Ansi_ieee Std 519-1981 Guide For Harmonic Control And Reactive Compensation Of Static Power Conve.pdf

ANSI/IEEE Std 519-1981

IEEE Guide for Harmonic Control and Reactive Compensation of Static Power Converters

Published by The Institute of Electrical and Electronics Engineers, Inc 345 East 47th Street, New York, N Y 10017, USA April 27, 1981

SHO 7 9 71

A

ANSI/IEEE Std 519-1981

A n American National Standard

IEEE Guide for Harmonic Control and Reactive Compensation of Static Power Converters

Sponsor Static Power Converter Committee of the Industry Applications Society

Approved December 20, 1979 IEEE Standards Board

Approved April 29,1983 American National Standards Institute

@Copyright 1981 by

The Institute of Electrical and Electronics Engineers, Inc 345 East 47th Street, New York,NY 10017 N o part of this publication may be reproduced in any f o r m , in an electronic retrieval system o r otherwise, without the prior written permission of the publisher.

Approved December 20,1979

IEEE Standards Board Joseph L. Koepfinger, Chairman

Irvin N. Howell, Jr, Vice Chairman

Ivan G . Easton, Secretary G. Y. R. Allen William E. Andrus C. N. Berglund Edward Chellotti Edward J. Cohen Warren H. Cook R. 0. Duncan Jay Forster *Member emeritus

Harold S. Goldberg Richard J. Gowen H. Mark Grove Loering M. Johnson Irving Kolodny W. R. Kruesi Leon Levy

J. E. May Donald T. Michael* R. L.Pritchard F. Rosa Ralph M. Showers J. W. Skooglund W. E. Vannah B. W. Whittington

Foreword (This Foreword is not a part of IEEE Std 519-1981, IEEE Guide for Harmonic Control and Reactive Compensation of Static Power Converters.)

This guide was prepared by the Harmonic and Reactive Compensation Subcommittee of the IEEE Static Power Converter Committee. The subject is not new; it has been theoretically and experimentally investigated for more than fifty years. Widespread use of converters, accentuation of problems, and involvement of nonspecialized personnel are, however, new. When work was started in 1974, static power converters using solid state devices had been used in industry for about ten years. The technology had progressed to a state that promised increased use of these devices in application from home use t o heavy industrial use. The need for a guide t o set practical limits on power system noise from these devices became apparent. During the past five years, patterns have been established where the interaction between static power converters and reactive compensation equipment have led t o practices for correcting problems that occur. This guide has application guidelines t o control interaction between these two types of equipment. At the time it approved this guide the IEEE Subcommittee on Harmonic and Reactive Compensation of Static Converters of Electric Power had the following membership: Ray P. Stratford, Chairman

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D. L. Ashcroft W. H. Bixby J. H. Galloway N. C. Herndon D. Human A. J. Humphrey*

0. Johnson A. Kirsh

S. T. Kohn A. Kusko E. J. Luoma D. McLellont

W. E. Newellt J. H. Ottevangers R. G. Schieman D. E. Steeper L. F. Stringer R. V. Wachter

*past secretary *deceased

This guide was prepared by a working group of the IEEE Subcommittee on Harmonic and Reactive Compensation of Static Converters of Electric Power. The membership of the working group was: R. P. Stratford, Chairman D. L. Ashcroft W. H. Bixby W. R. Caputo R. Edward J. H. Galloway H. A. Gauper N. C. Herndon D. Human A. J. Humphrey *deceased

0. Johnson A. F. Kirsch A. Kusko A. Ludbrook E. J. Luoma H. A. McColeman D. McLellont W. E. Newellt J. H. Ottevangers

D. H. Potter R. G. Schieman J. Simons H. M. Schlicke D. E. Steeper L. F. Stringer R. V. Wachter D. C. Washburn J. A. 1. Young

IEEE Standards documents are developed within the Technical Committees of the IEEE Societies and the Standards Coordinating Committees of the IEEE Standards Board. Members of the committees serve voluntarily and without compensation. They are not necessarily members of the Institute. The standards developed within IEEE represent a consensus of the broad expertise on the subject within the Institute as well as those activities outside of IEEE which have expressed an interest in participating in the development of the standard. Use of an IEEE Standard is wholly voluntary. The existence of an IEEE Standard does not imply that there are no other ways to produce, test, measure, purchase, market, or provide other goods and services related to the scope of the IEEE Standard. Furthermore, the viewpoint expressed a t the time a standard is approved and issued is subject to change brought about through developments in the state of the art and comments received from users of the standard. Every IEEE Standard is subjected to review at least once every five years for revision or reaffirmation. When a document is more than five years old, and has not been reaffirmed, it is reasonable to conclude that its contents, although still of some value, d o not wholly reflect the present state of the art. Users are cautioned to check to determine that they have the latest edition of any IEEE Standard. Comments for revision of IEEE Standards are welcome from any interested party, regardless of membership affiliation with IEEE. Suggestions for changes in documents should be in the form of a proposed change of text, together with appropriate supporting comments. Interpretations: Occasionally questions may arise regarding the meaning of portions of standards as they relate to specific applications. When the need for interpretations is brought to the attention of IEEE, the Institute will initiate action to prepare appropriate responses. Since IEEE Standards represent a consensus of all concerned interests, it is important to ensure that any interpretation has also received the concurrence of a balance of interests. For this reason IEEE and the members of its technical committees are not able to provide an instant response to interpretation requests except in those cases where the matter has previously received formal consideration. Comments on standards and requests for interpretations should be addressed to: Secretary, IEEE Standards Board 345 East 47th Street New York, NY 10017 USA

Contents SECTION

PAGE

1. IntroductionandScope ...................................................... 1.1 Introduction .......................................................... 1.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7 7 7

2. Definitions and Letter Symbols ................................................ 2.1 Definitions ........................................................... 2.2 Letter Symbols ........................................................

7 7 9

3. References ................................................................ 3.1 Standards References ................................................... 3.2 References ............................................................

11

4. Converter Theory and Harmonic Generation ......................................

.......................................................... 5. Reactive Power Compensation and Harmonic Control Techniques ..................... 5.1 Converter Power Factor ................................................. 4.1 Introduction

5.2 Reactive Power Compensation ............................................ 5.3 Problems and Control of Harmonics ........................................ 6 . Calculation Methods ........................................................ 6.1 Calculation of Harmonic Currents .......................................... 6.2 System Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 Telephone Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4 Line Notching Calculations (For Low Voltage Systems) ......................... 6.5 Distortion Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.6 System Calculation (Low Voltage, Below 1000 V) ............................. 6.7 Power Factor Improvement Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11 11

11 11 15 15 17 21 22 22 22 24 24 26 26 27

7. Measurements ............................................................. 7.1 LineNotching ......................................................... 7.2 Harmonics ............................................................ 7.3 Telephone Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4 Flicker ............................................................... 7.5 Power Factor Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8. Recommended Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1 LineNotching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2 Power Factor Correction ................................................. 8.3 Harmonics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4 Telephone Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5 Flicker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31 31 31 31 34 34 36 40

9 . Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1 Books and General Discussion ............................................. 9.2 Real and Wattless Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 Waveform Analysis and Measurement Techniques .............................. 9.4 Standards and Engineering Recommendations ................................ 9.5 Waveform Analysis and Means for Harmonic Suppression/Power Averaging . . . . . . . . . . 9.6 Effects on Components and Systems ........................................

42 42 43 44 44 45 48

28 29 30 30

FIGURES

Fig 1 Fig 2 Fig 3 Fig 4 Fig 5 Fig 6 Fig 7 Fig 8 Fig 9 Fig 10 Fig 11 Fig 12 Fig 13 Fig 14 Fig 15 Fig 16 Fig17 Fig 18 Fig 19 Fig 20 Fig 21 Fig 22 Fig 23 Fig 24 Fig 25 Fig26 Fig 27 Fig 28 Fig 29

PAGE

Current and Voltage Wave Forms Delta. Six.Phase. Y.Double Way . . . . . . . . . . . . . . . . 12 Relations Among Angles Used in Converter Theory ............................ 14 Theoretical and Typical Values of Harmonic Current For a Six-Pulse Converter . . . . . . . 15 Relationship Between Distortion Displacement and Total Power Component . . . . . . . . . 15 Total Power Factor of Six-Pulse and Twelve-Pulse Converters. a = 0 . . . . . . . . . . . . . . . . 16 Determination of Displacement Power Factor (Neglecting Transformer Exciting Current) ................................... 16 17 Reactive Power Versus dc Volts of Converter ................................. Effect of Reactive Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Capacitors Switched in Binary Values ....................................... 18 Static VAR Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Three-phase Diagram of One Bank of Capacitors ............................... 19 Self Saturating Reactor Scheme ............................................ 19 Power System Showing Harmonic Current and Voltage Influences . . . . . . . . . . . . . . . . . 20 Impedance Diagram of Power System ....................................... 23 Three-phase Full Wave Converter .......................................... 24 Voltage Notches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 InductanceDiagram .................................................... 25 Typical Power System and Equivalent Diagram ................................ 27 Power-Reactive Triangle for Power Factor Correction ........................... 28 Test Circuit for Measuring Current and Voltage Using Potential Transformer and Current Transformer .......................... 29 Notch Depth Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Simplified Diagram. Power Distribution System ............................... 32 Converter Connection t o Distribution System ................................. 33 Power System Showing Paralleling Between System and Shunt Capacitance Reactances ......................................... 34 Power System with Shunt Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Shuntpower Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Theoretical Voltage Distortion Versus Short-circuit Ratio for Six- and Twelve-Pulse Rectifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 1960 TIF Weighting Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Maximum Permissible Voltage Fluctuations .................................. 41

TABLES

Table 1 Harmonic Currents Present in Input Current t o a Typical Static Power Converter in Per-Unit of the Fundamental Current . . . . . . . . . . . . . . . . . . 22 Table 2 Low Voltage System Classification and Distortion Limits for 460 V Systems . . . . . . . . 34 36 Table 3 Typical Filter Configuration Versus System Size .............................. Table 4 Voltage Distortion Limits for Medium and High Voltage Power Systems . . . . . . . . . . . 36 38 Table 5 1960 Single Frequency TIF Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Table 6 Typical 1.T Values for 48 V dc Converters .................................. Typical 1.T Values for 48 V dc Ferroresonant Converters ....................... 39 Table 7 Table 8 Balanced I * TGuidelines for Converter Installations. Tie (Supply) Lines . . . . . . . . . . . . 40

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A n American National Standard

IEEE Guide for Harmonic Control and Reactive Compensation of Static Power Converters

frequencies. Additional useful definitions will be found in ANSI/IEEE Std 100-1977,Standard Dictionary of Electrical and Electronic Terms, IEEE Std 223-1966, Standard Definitions of Terms for Thyristors, IEEE Std 59-1962, Standard Semiconductor Rectifier components, ANSI C34.2-1968, Practices and Requirements for Semiconductor Power Rectifiers, and ANSI/IEEE Std 444-1973, Standard Practices and Requirements for Thyristor Converters and Motor Drives: Part I -- Convertersfor DC Motor Armature Supplies.

1. Introduction and Scope 1.1 Introduction. Static power converters of electric power are widely used in industry for a variety of purposes, such as electrochemical power supplies, adjustable speed drives, and uninterruptible power supplies. These devices are useful because they can convert ac to dc, dc to ac, and ac to ac. This characteristic, however, changes the sinusoidal nature of the ac power current (and consequently the ac voltage drop), resulting in the flow of harmonic currents in the ac power system that can cause interference with communication circuits and other equipments. When reactive power compensation is used with converters, resonance conditions can cause high harmonic voltages and currents when they occur at a harmonic associated with the converter.

commutation. The transfer of unidirectional current between thyristor (or diode) converter circuit elements that conduct in succession. converter. An equipment that changes electrical energy from one form to another. A semiconductor converter is a converter that uses thyristors or diodes as the active elements in the conversion process.

1.2 Scope. This guide applies to all types of static power converters used in industrial and commercial power systems. The purpose is to discuss the problems, be an application guide, and recommend limits of disturbances to the ac power distribution system which affect other equipments and communications. This guide is not intended to cover the effect of radiofrequency interference.

deviation from a sine wave. A single number measure of the distortion of a sinusoid due to harmonic components. It is equal to the ratio of the absolute value of the maximum difference between the distorted wave and the fundamental to the crest value of the fundamental. deviation from a sine wave, maximum theoretical. For a nonsinusoidal wave, the ratio of the arithmetic sum of the amplitudes (rms) of all harmonics in the wave to the amplitude (rms) of the fundamental.

2. Definitions and Letter Symbols

distortion factor (harmonic factor). The ratio of the root-mean-square of the harmonic content to the root-mean-square value of the fundamental quantity, expressed as a percent of the fundamental.

2.1 Definitions. Definitions given herein are tailored specifically to the harmonics generated by static power converters at utility system

7

IEEE Std 519-1981

sum of squares of amplitudes of all harmonics square of amplitude of fundamental

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

integral multiple of the fundamental frequency.

*loo%

NOTE: For example, a component, the frequency of which is twice the fundamental frequency, is called a second harmonic.

harmonic, characteristic. Those harmonics produced by semiconductor converter equipment in the course of normal operation. In a six pulse converter, the characteristic harmonics are the nontriple odd harmonics, for example, the 5th, 7th, l l t h , 13th, etc.

filter. A generic term used in describing those types of equipment whose purpose is t o reduce the harmonic currents or the voltage flowing in or being impressed upon specific parts of an electrical power system, or both. filter, damped. A filter generally consisting of combinations of capacitors, reactors, and resistors which have been selected in such a way as t o present a low impedance over a broad range of frequencies. The filter usually has a relatively low Q ( X / R ) .

h=kqk1 k = any integer q = pulse number of converter harmonic, noncharacteristic. Those harmonics which are not produced by semiconductor converter equipment in the course of normal operation. These may be a result of beat frequencies, a demodulation of characteristic harmonics and the fundamental, or unbalance in the ac power system or unsymmetrical delay angle.

filter effectiveness (shunt). Defined by two terms : pf = the impedance ratio which determines the per unit current which will flow into the shunt filter ps = the impedance ratio which determines the per unit current which will flow into the power source pf should approach unity and ps should be very small at the tuned frequency.

harmonic factor. The ratio of the root-meansquare (rms) value of all the harmonics t o the root-mean-square value of the fundamental. harmonic factor (for voltage)

=

4ES2+ ES2+ El2.. . E,

filter, high-pass. A filter having a single transmission band extending from some cutoff frequency, not zero, up t o infinite frequency. filter, series. That type of filter which reduces harmonics by putting a high series impedance between the harmonic source and the system t o be protected.

impedance ratio factor. The ratio of the source impedance at the point in the system under consideration to the equivalent total impedance from the source t o the converter circuit elements which commutate simultaneously.

filter, shunt. That type of filter which reduces harmonics by providing a low impedance path to shunt the harmonics from the source away from the system t o be protected.

I

T product. The inductive influence expressed in terms of the product of its root-mean-square magnitude in amperes ( I ) times its telephone influence factor (TIF).

filter, tuned. A filter consisting generally of combinations of capacitors, inductors, and resistors which have been selected in such a way as t o present a relative minimum (maximum) impedance t o one or more specific frequencies. For a shunt (series) filter the impedance is a minimum (maximum). Tuned filters generally have a relatively high Q ( X / R ) .

kV

T product. Inductive influence expressed in terms of the product of its root-mean-square magnitude in kilovolts (kV) times its telephone influence factor (TIF). line voltage notch. The dip in the supply voltage to a converter due t o the momentary shortcircuit of the ac lines during a commutation

harmonic. A sinusoidal component of a periodic wave or quantity having a frequency that is an

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IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

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interval. Alternatively, the momentary dip in supply voltage caused by the reactive drops in the supply circuit during the high rates of change in currents occurring in the ac lines during commutation.

telephone influence factor (TIF). Of a voltage or current wave in an electric supply circuit, the ratio of the square root of the sum of the squares of the weighted root-mean-square values of all the sine-wave components (including alternating current waves both fundamental and harmonic) t o the root-mean-square value (unweighted) of the entire wave.

power factor, displacement. The displacement component of power factor; the ratio of the active power of the fundamental wave, the watts, t o the apparent power of the fundamental wave, in volt-amperes (including the exciting current of the thyristor converter transformer).

2.2 Letter Symbols. The following set of letter symbols is used in thyristor converter circuit analysis and calculation of converter characteristics.

2.2.1 Subscripts 0 = a t no load; for example, Ed0 1 = at rated load, or fundamental; for example Ed1 or Il d = direct current and voltage h = order of harmonic i = ideal 1 = converter side of transformer, phase-tophase, el L = line side of transformer p = inherent pu = per-unit quantities s = converter side of transformer, phase-toneutral 2.2.2 Letter Symbols a = delay angle y = margin angle (for inverter operation) p = commutation angle p f = impedanceratio ps = impedanceratio cos @1 = displacement power factor (including transformer exciting current) cos 6 = distortion component of power factor Uh = amplitude of sine term for the h harmonic in Fourier expansion (crest value) bh = amplitude of cosine term for the h harmonic in Fourier expansion (crest value) Ch = amplitude of resultant for the h harmonic in Fourier expansion (crest value) Dx = commutating reactance transformation constant (applies only t o the first mode of operation after the light load transition) E,, = crest working voltage Ed = average direct voltage under load Edo = theoretical direct voltage (average direct voltage at no load or light transition load, assuming zero phase

power factor (total). The ratio of the total power input in watts t o the total volt-ampere input t o the converter. NOTES: (1) This definition includes the effect of harmonic components of current and voltage, the effect of phase displacement between current and voltage, and the exciting current of the transformer. Volt-amperes is the product of rms voltage and rms current. ( 2 ) The power factor is determined at the ac line terminah of the converter.

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pulse number. The total number of successive nonsimultaneous commutations occurring within that converter circuit during each cycle when operating without phase control. It is also equal t o the order of the principal harmonic in the direct voltage, that is, the number of pulses present in the dc output voltage in one cycle of the supply voltage. quality factor. Two K times the ratio of the maximum stored energy t o the energy dissipated per cycle at a given frequency. An approximate equivalent definition is that the Q is the ratio of the resonance frequency to the bandwidth between those frequencies on opposite sides of the resonance frequency where the response of the resonant structure differs by 3 dB from that at resonance. If the resonant circuit comprises an inductance L and a capacitance C in series with an effective resistance R , the value of Q is:

Q = L ( L $5) R C short-circuit ratio. Of a semiconductor converter is the ratio of the short-circuit capacity of the bus in MVA at the point of converter connection t o the rating of the converter in MW. 9

IEEE Std 519-1981

Ed1 = =

Ef =

Eii = EL = En = Er=

E, = Ex =

f =

F,

=

IC1

=

Id =

le = I, = Ih =

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

control and zero forward voltage drop) direct rated voltage commutating voltage total forward voltage drop per circuit element initial reverse voltage ac system line-to-line voltage ac system line-to-neutral voltage direct-voltage drop caused by resistance losses in transformer equipment, plus interconnections not included in Ef transformer dc (secondary) winding line-to-neutral voltage (rms) direct-voltage drop caused by commutating reactance frequency of ac power system IcXc/Es commutating reactance factor transformer dc winding (secondary) coil rms current average dc load current of the rectifier, in amperes transformer exciting current direct current commutated between two rectifying elements in a single commutating group harmonic component of I of the order indicated by the subscript

output power, in watts pulse number of a converter line-to-neutral commutating resistance for a set of commutating groups, in ohms Rcn = equivalent line-to-neutral commutating resistance, in ohms, for a set of commutating groups referred t o the ac (primary) winding of a converter transformer R, = line-to-neutral commutating resistance, in ohms, for a single commutating group R, = effective resistance of the ac (primary) winding R, = effective resistance of the directcurrent (secondary) winding S = circuit factor [l for single-way; 2 for bridge (double-way)] Xc = line-to-neutral commutating reactance, in ohms, for a set of commutating groups Xcpu = per-unit commutating reactance Xcn = equivalent line-to-neutral commutating reactance, in ohms, for a set of commutating groups referred t o the ac (primary) winding of a converter transformer (Xcn= D,Xe) X, = line-to-neutral commutating reactance, in ohms, for a single commutating group X L = reactance of supply line, in ohms (per line) X L , ~= per-unit reactance of supply line, expressed on base of rated volt-amperes a t the line terminals of the transformer ac (primary) windings X T , ~= per-unit reactance of transformer, expressed on base of rated volt-amperes a t the line terminals of the transformer ac (primary) windings 2, = line-to-neutral commutating impedance, in ohms, for a set of commutating groups Zcn = equivalent line-to-neutral commutating impedance, in ohms, for a set of commutating groups referred t o the ac (primary) winding of a converter transformer 2, = line-to-neutral commutating impedance, in ohms, for a single commutating group Pd = g = Rc =

IH =

IL = Im = I, = IpL =

Is = I1 = Ilp = IlQ =

Ld

=

n =

P = Pr =

equivalent totalized harmonic component of IL alternating line current (rms) alternating line current (crest value) transformer ac (primary) winding coil current alternating line current corresponding t o the current in the ac (primary) winding during load loss test in accordance with 8.3.2.1 ANSI/IEEE Std 444-1973 transformer dc winding (secondary) line rms current fundamental component of IL power component of I1, in watts reactive component of I1 inductance of the dc reactor, in henrys number of simple converters pulse number of commutating group transformer load losses, in watts (including resistance and eddy current losses)

NOTE: Commutating reactances due to various circuit elements may be indicated by subscript as in X,, X c 2 , or X c and ~ X c for ~ transformers and line, respectively.

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IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

3. References

[14] JOHNSON, E. R., Static High Speed VAR Control for Arc Furnace Flicker Reduction. Proceedings American Power Conference, vol 34,1972, pp 1097-1105.

[l]CHRISTENSEN, E. F., Analysis of Rectifier Circuits. AIEE Transactions, vol 63,1944, pp 1048-1058.

[ 151 ANSI C34.2-1968 (R 1973), Practices and Requirements for Semiconductor Power Rectifiers'

[2] READ, J. C. The Calculation of Rectifier and Converter Performance Characteristics. Journal IEE, vol92, pt 11,1945, pp 495-509.

[16] ANSI/IEEE Std 18-1980, Shunt Power Capacitors

[31 PELLY, B. R. Thyristor Phase-Controlled Converters and Cycloconverters. New York: John Wiley, 1971.

[17] ANSI/IEEE Std 100-1977, Standard Dictionary of Electrical and Electronics Terms

[4] TRUXAL, J. G. Automatic Feedback Control System Synthesis. New York: McGrawHill, 1955, pp 375-390.

[ 181 ANSI/IEEE Std 444-1973, Standard Practices and Requirements for Thyristor Converters and Motor Drives: Part I - Converters for dc Motor Armature Supplies

[5] KIMBARK, E. W. Direct Current Transmission - vol I, New York: Wiley-Interscience, 1971 (see Ch 8, Harmonics and Filters, which includes a list of 62 references).

[19] IEEE Std 59-1962, Standard for Semiconductor Rectifier Components [20] IEEE Std 223-1966, Standard Definitions of Terms for Thyristors

[ 61 AIEE COMMITTEE REPORT. Inductive

Coordination Aspects of Rectifier Installations. AIEE Transactions, vol65, 1946, pp 417-436. A

[ 211 ANSI/IEEE Std 368-1977, Recommended Practice for Measurement of Electrical Noise and Harmonic Filter Performance of HighVoltage Direct-Current Systems.

[7] Survey of Arc-Furnace Installations on Power Systems and Resulting Lamp Flicker. Subcommittee Report, AIEE Transactions, vol 76, pt 11, Sept 1957, pp 170-183.

[22] IEEE Std 469-1977, Recommended Practice for Voice-Frequency Electrical-Noise Tests of Distribution Transformers

[8] CONCORDIA, C., Selection of Buffer Reactors and Synchronous Condensers on Power Systems Supplying Arc-Furnace Loads. AIEE Transactions, vol 76, pt 11, Jul 1957, pp 123135.

4. Converter Theory and Harmonic Generation

[9] KENDALL, P. G. Light Flicker in Relation t o Power-System Voltage Fluctuation. Proceedings IEE, ~ 0 1 1 1 3 , 1 9 6 6pp , 471-479.

4.1 Introduction. A power converter by definition changes electrical energy from one form t o another. This change is accomplished by periodic switching in the conducting circuits of the converter. A three-phase bridge converter (see Table 6, Circuit No 23, ANSI C34.2-1968, [15] ), for example, connects the line-voltage with the highest instantaneous value of voltage t o the load. (See Fig 1.) The switches in the example of Fig l ( a ) are thyristors. Combinations of one odd and one even numbered thyristor will connect the ac source t o the load.

[ 101 MULCAHY, J. A. and LUDBROOK, A. A. New Flicker Correcting System for Arc Furnaces. Journal of Metals, Apr 1967, pp 63-66.

[ll] FRANK, H. and LANDSTROM, B. PowerFactor Correction with Thyristor-Controlled Capacitors. ASEA Journal, vol 44, 1971, pp 180-1 84. [ 121 Thyristor-Switched Capacitors Curb Furnace Flicker. Electrical Review, Aug 9, 1974, pp 164-166.

[13] OLTROGGE, A. R. Fundamental Criteria for Large Arc Furnace Power Systems. Journal of Metals, Jan 1971, pp 53-64.

'ANSI documents are available from the American National Standards Institute, 1430 Broadway, New York, N. Y. 10018.

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Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

I ,E

L 4

(a) Table 6, Circuit No 23 [ 151

DC WINDING

R"

R.

(b) Transformer dc Winding Volts

(c) Current in Rectifying Elements

(a) Voltage Across No 1 [15] Rectifying Element

(e) Current in dc Winding Rt

GL I

I---?+

2%

TId

(g) ac Table Line6,Current CircuitsIfl Nofor 24 and No 25 [ 151

2Ia ES

I++-d

fi Id E.

(f) ac Line Current Hl for Table 6, Circuits No 23 and No 26 [ 151 I-

Fig 1 Current and Voltage Wave Forms Delta A, Six-Phase, Y, Double Way

12

?,"4

IEEE

Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

A

I

The resulting unidirectional voltage is made up of the tops of sinusoidal waves, each top sixty degrees wide. It is a dc voltage with superimposed high-frequency ripple. Harmonic analyses show that the ripple voltage consists of the supply voltage with a frequency of multiples of six times the fundamental frequency. The dc load circuit and the dc load itself contain inductance which will flatten the load current. In converter theory, for convenience sake, the dc current is considered to be constant. As shown in Fig l(f), the line currents at the ac side will consist of flat topped waves. Power, the product of current and voltage, at the dc side contains harmonics due to the harmonics in the voltage. Since no energy storage can take place in the elements of a converter, the power balance of input and output requires harmonics in the input power, and thus harmonic currents will flow in the supply lines. Energy balance considerations show, and Fourier analysis of the square waves confirms, that each 6n harmonic in the dc voltage requires harmonic currents of frequencies 6n + l and 6n - l in the ac line. The magnitude of the harmonic current is inversely proportional to the harmonic number.

29, 31, etc are 180' out of phase, thereby cancelling these currents when they are used in a circuit such as Table 6, Circuit No 31 [15]. The square current waves of Fig l ( c ) are based on the assumption that the line current will transfer instantaneously when the higher ac voltage causes a diode to start conducting. In practice there will be reactance in the circuit which will cause the current transfer to be more gradual (Fig 2), reducing the slope of the leading and trailing edges of the square waves and reducing the magnitude of the ac current harmonics. The time to transfer current is called the commutating angle ( p ) . Figure 3 shows the relationship of theoretical value to a typical value of harmonic current. The switching elements of the bridge in Fig l ( a ) are diodes. They will start conducting as soon as a voltage is applied in the forward, or current-carrying, direction. Thyristors not only need a forward voltage, but also a firing pulse t o start conducting. Output voltage can be controlled by delaying the firing pulse with reference to the voltage cross-over time. Firing delay influences the manner in which current is transferred from phase-to-phase, and thus also influences the magnitude of the current harmonics. The delay angle is called a. This example of one use of a semiconductor device demonstrates the production of harmonic currents. These currents flowing in the circuits of a power system can cause problems if a resonant circuit exists at the frequency of any of these currents. These currents can excite these resonant circuits and produce large oscillating currents which can overload circuit elements causing failure or operation of protective equipment. These higher than fundamental frequency currents can produce noise on communication circuits, either voice or data transmission, by electrostatic or electromagnetic coupling. The ability of the thyristor to delay the commutation of the current t o the more positive phase (operation at reduced voltage output) increases the angle by which the voltage leads the current, and thus reduces the power factor. Some installations compensate for this reduction in power factor by capacitors; this increases the chance of setting up parallel resonances. The electrical circuit within an industrial plant is not isolated from the utility providing the electric power. The resonant conditions described in this Guide are a result of the

h = kq+1 = I1 Ih h

where h = harmonic order k = any integer q = pulse number of circuit I1 = fundamental current Therefore, for a 6-pulse converter, such as Table 6, Circuits 23, 25, or 25 [15] the harmonic currents in the ac power supply would theoretically be: Harmonic Order and Current Magnitude in Per Unit of the Fundamental 5

7

11

13

17

19

23

25

0.2000 0.1429 0.0909 0.0769 0.0588 0.0526 0.0435 0.0400

-

A transformer connection of Y-Y (Table 6, Circuit No 24) [15] or A-A (Table 6, Circuit No 25) [15] would reflect an ac line current as shown in Figure l(g). This has the same harmonics as Table 6, Circuit No 23 and Circuit No 26 [15] except the 5, 7, 17, 19, 13

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

/ RECTIFIER

I

I

I I I I I

I

I

I

I I

I I I

I I

I I INVERTER I

Fig 2 Relations Among Angles Used in Converter Theory

_14

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

A twelve pulse converter has theoretical value of approximately 0.988. q sin = pF = = q where

TYPICAL d m

5th

7th

$5

: g

0 0

0 0 0 0

mu3

13th

17th

11th

q # 1 For purpose of calculations, transformer magnetizing current is neglected. With commutation overlap and phase retard, the equation becomes: 19th

23rd

25t.h

O R D E R OF HARMONIC

Fig 3 Theoretical and Typical Values of Harmonic Current For a Six-Pulse Converter

h

where Ed' = Ed + + Ef Ed = average direct voltage under = resistance drop

combination of inductive and capacitive reactances in the total circuit. Resonant problems that arise must be solved by a joint effort between the industrial user and the utility by approaching the problem on a system basis. This guide suggests limits of voltage distortion and recommends practices t o minimize the effects of the harmonic currents from static power converters.

load

E f = total forward drop per circuit element I d = d < load current supplied by the converter, in average amperes EL = primary line-to-line r m s voltage

Fig 4 Relationship Between Distortion Displacement and Total Power Component 1.oo

5. Reactive Power Compensation and Harmonic Control Techniques

0.98 0.96

5.1 Converter Power Factor. The power factor of a converter is made up of two components: displacement and distortion. The effect of the two are combined into the total power factor. Their relationship is shown in Fig 4. The displacement component is the ratio of the active power of the fundamental wave, in watts, to the apparent power of the fundamental wave, in voltamperes. This is the power factor as seen by the utility metering by watthour and varhour meters. The distortion component is that part associated with the harmonic voltages and currents present. The power factor of a six pulse converter on a theoretical square wave current basis is:

0.94 0.92 0.90 0.88 0.86 0.84 0

20

10

- =-Ex IC xc

E,

PF = 3/, = 0.955 (a= 0 )

15

E,

30

REACTANCE FACTOR

(%I

40

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

IL= ac primary line current, in rms amperes a = commutation angle p = angle of overlap or commutating angle Ed0 = theoretical dc voltage E, = direct voltage drop due t o commutating reactance where

ing current. Transformer magnetizing current (Imag) correction is approximately

where cos

power factor, not including transformer magnetizing current Static power converters need a supply of reactive power whether they are rectifying or inverting. In both cases the thyristor can only turn the current on after the voltage has become more positive than the previous phase voltage. The closer the operation is t o zero volts dc (Fig 7), the more reactive power is required with the same output current. The reactive power requirements of commonly used converter circuits is a function of load and output voltage and may be calculated. It is possible to reduce reactive power requirements of static power converters by: (1)Limiting the amount of phase control required during normal operation (limit a) (2) Lower reactance of converter transformers (limit p ) (3) Asymmetrical or sequential control of converters (limit a)

sinp [ 2 + cos ( p + 2 a ) ] -p [l + 2 cos a cos ( p + a ) ] f(p,a)= [ 2 71 cos a cos ( p + a)]2

-

The displacement factor, cos 4; =

sin2p ( p 2 + sin'p

- 2p sin p COS^)^

( a =0)

Displacement power factor is the power factor that is measured by metering equipment, and is the one on which utility billing is based. The distortion power factor (cos 6 ) is the ratio of the fundamental component of ac line current t o the total line current (I~/IL). Figure 6 shows the relationship between displacement power factor and system reactance. This does not allow for transformer magnetizFig 5

Total Power Factor of Six-Pulse and

= displacement

Fig 6 Determination of Displacement Power Factor (Neglecting Transformer Exciting Current)

Twelve-Pulse Converters, a = 0

1

0.98

PERCENT VOLTAGE

nn

I.UU

0.96 0.96

0.92 0.94

0.88

-

0.92

0.84

0

0.80 d

0.90

0.76 0.72

0.88

0.68

0.64 0

5 EX (7cJ -

0

10

10

5

E, ( 7 ) -

REACTANCE FACTOR

Ed 0

h o

16

15

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

e

using any of the above methods. Voltage control by regulating transformer can reduce the amount of voltage control required by phase retard in the converter. A lower reactance converter transformer may mean that the short circuit levels in the converter are too high. Asymmetrical or sequential control may be economical if the application requires large enough converters so that two converter sections are needed.

5.1.1 Limiting Phase Control. Static power converters are usually designed t o operate from a power system whose voltage range is from +lo% t o - 5%of nominal. If the converter is t o invert, it is usually designed to operate with a *lo% voltage. This means that the power system voltage can vary over &lo% and stili have satisfactory operation of the converter. If some other means of voltage control is used t o maintain the power system voltage in a narrower range, the secondary voltage of the converter transformer can be chosen so that, during normal operation, the converter is operated more nearly fully phased on (less retard). If the load that the converter is feeding requires a wide range of voltage, voltage control from transformer taps will limit the amount of phase control used by the converter. 5.1.2 Lower Reactance Transformer. Reactive power is required t o furnish the magnetizing component of current t o transformers. If the transformer is designed to have a minimum reactance, the reactive power requirement is also minimum and it reduces the commutation angle. 5.1.3 Asymmetrical or Sequential Control. By designing a static power converter to operate with two converter sections in series, it is possible to operate one section fully phased on and the second section adding or subtracting from the voltage of the first section. Because a smaller part of the total static converter is operating with phase control, a smaller amount of reactive power is required. 5.1.4 Other Considerations. The ability to reduce the reactive power requirements of a static power converter is sometimes limited by the number of units involved and the economics of

5.2 Reactive Power Compensation. The rate structures electric power utility companies are made up of two main components: demand charge and energy charge. The first is a result of the investment in equipment t o furnish that amount of total power t o the customer. The second is the result of fuel that must be expended t o generate the energy used. The total power (kVA) is made up of two components in quadrature. If the kVA can be reduced by furnishing reactive power locally, the demand charge can be minimized. Reactive power sources are: (1)Static power capacitors (2) Synchronous machines (3) Force commutated static power converters 5.2.1 Reactive Power Compensation Using Static Power Capacitors. Power capacitors are an inexpensive source of reactive power (leading vars). The vars are proportional to the square of the applied voltage. The reactance of a capacitor bank varies inversely with the frequency 1 Xcap= 2nfC So for high frequencies they provide low impedance. The leading current drawn by the capacitors give a voltage rise through the inductive reactance of the power system which raises the operating voltage level. They cannot by themselves control reactive power and voltages. They must be switched in groups to provide

Fig 7 Reactive Power Versus dc Volts of Converter

I

VARS (PER UNIT)

Fig 8 Effect of Reactive Power

DC VOLTS (PER UNIT:

17

IEEE

Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

variable reactive power. Four methods of controlling vars using capacitors, in the order of complexity are : (1)Switching by power circuit breaker or vacuum switches (2)Back-to-back phase control thyristor switching of a reactor in parallel with the capacitor bank (3) Back-to-back thyristor switching of capacitors which will turn on or off at current zero (4) Saturable reactor in parallel with capacitor bank 5.2.1.1 Switching Power Capacitors by Circuit Breakers or Vacuum Switches. For controlling reactive power on a continuous basis switching power capacitors by circuit breakers or vacuum switches requires a switching device that can be operated with high frequency and can interrupt at current zero with a high voltage across the contacts without reignition. Because of these requirements, this method is used only for switching larger banks once or twice a day when the demand changes from normal t o light load conditions. The switching device has the special requirement of being able t o interrupt a current which leads the voltage by 90". Where the limitations are not an operating disadvantage, this method of controlling vars is most economical. 5.2.1.2 Back-to-Back Phase Control Thyristor Switching of Reactor. Back-to-back phase control thyristor switching in parallel with capacitors has the advantage of smooth var control over the range of the equipment. By

T T T T

TO PLANT LOADS

1

2

4

8

Fig 9 Capacitors Switched in Binary Values switching the current t o the reactor, the problems of switching leading current is avoided. Thyristor switching of a balanced three-phase load causes 5 , 7, etc harmonic currents. Therefore, the capacitors may be divided into three or more sections with tuning reactors to filter these harmonics. The reactor var rating is normally equal t o the capacitor rating t o obtain full control. More capacitors can be supplied if a bias of vars is needed on the system. 5.2.1.3 Back-to-Back Thyristor Switching of Capacitors at Zero Current. Back-to-back thyristor switching of capacitors at zero current leaves the capacitor charged with either a positive or negative full charge on the capacitor. The thyristor's fine control allows the switchingon of the capacitor when the system voltage equals the charged capacitor voltage. This eliminates any transients on the system. The capacitors are switched in finite steps as reactive power is needed. The switched capacitors can

Fig 10 Static VAR Control NOTE: This system can control vars on a per-phase basis.

TO PLANT LOADS

r7'7-l5

7

11

13

l1A KMON I<' F I LT ERS

18

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

-

be tuned with a reactor to filter harmonics on the system. This system can also be used with a fixed bias of capacitors t o provide a base vars with the switched capacitors to be used for variable vars. This system can be regulated on a per-phase basis. The control of this equipment is more complicated than switching a paralleled reactor. 5.2.1.4 Saturable Reactor in Parallel with a Capacitor Bank. A saturable reactor in parallel with a capacitor bank provides a variable var supply that requires no external control circuitry. This system consists of a self-saturating reactor in parallel with a capacitor bank which can be arranged into tuned series circuits. The self-saturating reactor draws heavy currents at overvoltages so that the voltage drop through the system reactance counteracts the voltage rise at the load. As the system voltage decreases, the reactor draws less current and the paralleled capacitors furnish the vars needed at the load. The harmonics generated by iron saturation are somewhat compensated by the winding configuration; however, the paralleled capacitor is usually furnished with series tuned circuits t o the major harmonics, 5, 7, etc. 5.2.2 Reactive Power Compensation Using Rotating Machinery. Synchronous machines can be made t o operate with either a leading or lagging power factor by controlling the field excitation. This property can be used to provide reactive power compensation on a dynamic basis with the appropriate control strategy. A synchronous machine is referred t o as a synchronous condenser when it is dedicated solely to reactive power compensation. It will have no mechanical load and all the machine power will be available as reactive power. A

synchronous condenser is often used with a fixed capacitor bank equal to the machine vars. This will allow a total range of operation from zero t o twice the machine rating for leading vars with proper adjustment of the field excitation. A synchronous motor can be sized to provide leading vars. When the system includes synchronous motors, consideration should be given to this possibility since the incremental cost of providing leading vars can be quite attractive. Further, with proper control strategy, the vars can be adjusted t o the system requirements (power factor regulator). When synchronous machines are used t o provide power factor compensation, the following technical areas of interest should be considered: (1)Time profile of the var and kW demand on the bus to be protected (2) Allowable voltage deviation on this bus (transient and steady-state) (3) Time profile of the vars the synchronous machine must provide in order to maintain the voltage deviation limits NOTE: The synchronous machine, by virtue of its stored magnetic energy, will be able t o provide instantaneous attenuation of a voltage disturbance. The field must be adjusted to provide complete attenuation. The time required can be reduced by field forcing with a static power converter field exciter.

(4)Compatibility with static power converters in such areas as: (a) Voltage unbalance sensitivity (b) AC line harmonic heating (c) Bearing currents (5) Control limits that will avoid: (a) Exceeding machine pullout torque capability (b) Exceeding machine thermal limit

Fig 11 Three-phase Diagram of One Bank of Capacitors

Fig 12 Reactive Power Compensation Using Rotating Machinery

L SATURATING

REACTOR

T 5th

T

7th

T

11th

HAKMOhlC I l l T t R 5

19

T

13th

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

5.2.3 Reactive Power Compensation Using Forced Commutated Converters. The technique of forcing commutation t o a different phase before the voltage has become more positive produces leading vars. An example of this type of converter is an inverter using a fuel cell or battery as an energy source.

Harmonic voltage generation can be controlled by the use of a number of different cancellation techniques, such as pulse multiplication and step wave which cancel the lower order harmonic pairs. Treatment of the remaining harmonics is quite different with the forced commutated converter. The inductance on the ac side of forced commutated converters offers a high impedance to the passage of the higher harmonic currents. In cases where the ac system is stiff relative t o the ac side reactance, no control of harmonic voltages at the ac bus is required. With weak ac systems, some filtering may be required. A small, high-pass shunt filter or a small capacitance bank suffices with 18-or 24-pulse configurations since the ac side inductance restricts harmonic current flow. Selfcommutated converters do not require reactive compensation (they can generate vars) and filters for the uncancelled harmonics are small.

Forced-commutated converters incorporate their own means for commutation and can commutate independently of the line voltage. The conversion parts of these systems are voltage sources rather than current sources as in linecommutated conversion. The forced commutated converter functions nearly the same as a conventional utility generator; that is, a voltage source behind an impedance. The converters have essentially no inductance on the dc side but do require additional inductance on the ac side. Reactive compensation is not required.

Fig 13 Power System Showing Harmonic Current and Voltage Influences (a) Schematic Diagram; (b) Impedance Diagram

AVERAGE O F SUBTRASIENT AND NEGATIVE SEQUENCE REACTANCE T,

CONVERTER TRANSFORMER

I

EXTENSIVE NETWORK (ASSUME NEGLIGIBLE REACTANCE COMPARED T O THAT OF T i )

iJ 20

CONVERTER

-.

COMPENSATION OF STATIC POWER CONVERTERS

-

-

5.3 Problems and Control of Harmonics. The diagram of Fig 13 shows a converter C supplied from a power source G over a three-phase line L,. The reactance of the source XG + xi2 and the line L, are in series with the converter transformer reactance Xt. If a harmonic current Ih flows between the converter and the source there will be harmonic voltage Eh = Ih Xh at location A. ( x h is the reactance of the source at the harmonic frequency h). When there is an extension L, for supplying other loads, the harmonic voltage at A will cause a harmonic current to flow over that line as well, although the power to the rectifier is supplied only over line L, . The higher the value of x h , the greater will be the harmonic voltage at A and the higher the magnitude of the harmonic currents flowing over line L,. Actually, the harmonic currents from a converter can flow into any part of an ac system to which it is connected, as determined by the impedances of the various branches of the system at the harmonic frequencies. The harmonic voltages and currents can be calculated. Inductive coupling between the ac power line and the telephone lines induces harmonic voltages on the telephone system which may cause noise levels high enough that it is impossible to understand messages being transmitted on the telephone lines. In recent years such telephone techniques as carrier devices (high frequency) facilities and the use of shielded cables have minimized the susceptibility of these communication circuits t o harmonics on power lines. There are still many cases where the pole line is shared by both the voice frequency telephone and power distribution systems so that harmonics can cause harmful affects on the communication system. Harmonic currents can cause excessive heating in rotating machinery. The harmonic currents of Izq + l are positive phase sequence currents and Izq l are negative phase sequence currents. On synchronous machines, these two currents add directly, causing additional heating in the solid rotor of large synchronous machines. This limits the amount of converter load that can be carried by synchronous generators. The converter loads frequently are small compared to the electric utility generator sizes, but local generation (for example, the user) may suffer severely. Noise from harmonic generation operating on regulating and control systems can give errone-

ous operation of these systems. Proper shielding or isolation of the signal leads can prevent most of these problems. On utility systems feeding domestic loads, interference with TV video signals by the harmonic currents generated by converters is usually the first indication of harmonic problems. Metering and instrumentation are affected by harmonic currents, particularly if resonant conditions occur which cause high harmonic voltage on the circuits. Induction disk devices such as watthour meters and overcurrent relays normally see only fundamental current, but phase unbalances caused by harmonic distortion can cause erroneous operation of these devices. On critical loads, torque pulsations caused by harmonic currents on ac motors can be harmful t o the process. They can also set up resonant conditions if the natural frequency of the mechanical system is excited by the harmonics. Ballasts for fluorescent or mercury lighting sometimes have capacitors which, together with the inductance of the ballast and circuit, have a resonant point. If this corresponds t o one of the generated harmonics, excessive heating and failure can result. Carrier systems that control remote devices can operate erroneously if the harmonics are generated close to the carrier signal frequency. Carrier systems for time clocks and off-peak control are two examples. Harmonic current can be controlled by several techniques. These include : (1)Shunt filters (2)Phase multiplication (3)Harmonic compensation or injection 5.3.1 Shunt Filters. Shunt filters for reduction of harmonic currents flowing into an ac power system consist of one or more tuned circuits consisting of series L-C circuits. The filter commonly used on HVDC transmission consists of individual circuits tuned for the 5, 7, 11 and 13 harmonics plus a high pass filter tuned near the 17 harmonic. Filters in industrial systems can be simpler because of the higher damping in the lower voltage systems. The need t o filter the higher order harmonics is related to the system short-circuit levels. The damping factor is dependent upon the X/R ratio of the circuit. 5.3.2 Phase Multiplication. Single-phase converters are commonly used for small loads. For lowest initial cost, a half wave circuit may be used where current requirements are small. For

-

-_

IEEE Std 519-1981

21

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

greater output and less generation of harmonics a full wave circuit can be used. The basic polyphase converter is a six-pulse unit. Theoretically, a twelve-pulse unit will eliminate the 5, 7, 17, 19, etc harmonic frequencies. Further phase multiplication will reduce other harmonic currents. For example, a 36-pulse circuit is usually constructed with six 6-pulse bridges, each of which is phase shifted 10" from the other transformers by a separate phase shifting transformer or additional coils in the primary windings. If one 6pulse unit is out of service, the harmonic current equivalent to that unit will be present. Large installations may require addition of shunt filters to minimize harmonic currents. Phase multiplication is most effective for an installation where converters operate such that equal sizes are operated with equal loading and phase retard. 5.3.3 Harmonic Injection. Harmonic currents can be eliminated by inducing harmonic fluxes in a core of a transformer with a 180" phase shift from the harmonic fluxes induced by the current flowing on the transformer secondary.

Table 1 Harmonic Currents Present in Input Current t o a Typical Static Power Converter in Per-Unit of the Fundamental Current Converter Pulses 6 12 18 24

5

7

0.175 0.11 0.026 0.016 0.026 0.016 0.026 0.016

Harmonic Order 11 13 17 19

23

25

0.045 0.029 0.015 0.010 0.009 0.008 0.045 0.029 0.002 0.001 0.009 0.008 0.007 0.004 0.015 0.010 0.001 0.001 0.007 0.004 0.002 0.001 0.009 0.008

monics are 25% of those computed for a sixpulse converter. The 25% factor appears t o be on the high side. A range of 15%t o 25% would be more accurate depending upon the equipment. These unbalances might be caused by: (1)Variations in voltage or impedance lineline in three-phase systems (possibly k2.596) (2) Differences in transformer winding ratios for Y and A connections (3) Differences in thyristor firing pulse angles between multipulse circuits (4) Variations in thyristor turn-off times. 6.1.1 Diversity Factors. A need exists to develop either diversity factors or a statistical method for calculating the harmonic current amplitudes of more than one converter connected t o a bus. 6.1.2 Harmonic Currents from Semiconverters and Cycloconverters. To estimate harmonic current amplitudes for semiconverters and other infrequently used circuits, it is recommended that the wave shape be estimated or obtained by test and standard Fourier analysis computer programs be used. Approximations can be used as described in [3] and [ 4 ] .

6. Calculation Methods This section recommends calculating methods for harmonic currents and voltages generated by converters, including their effect on telephone circuits and power systems. The effects on telephone circuits are described by TIF and 1.T product. The effects on power systems are described by distortion factor and line notching. Low-voltage system calculations use both distortion factors and line notching methods.

6.2 System Analysis. The circuit of Fig 1 4 should be analyzed at each frequency of interest by calculating series and parallel resonances. 6.2.1 Impedance as a Function of Frequency. The major impedance elements in the above circuit respond differently as frequency changes. The impedance of transmission lines is a complex relationship between the inductive and capacitive reactances. Using the fundamental frequency resistance and inductance of the transmission line, however, gives good results [ 51 . For most industrial systems, Z, and 2 , can be approximated by the short-circuit impedance. The impedance versus frequency characteristic of a transformer depends upon design, size, voltage, etc. Its load loss, I'R, will constitute 75% to 85% of the total transformer loss and about 75% of this is not frequency depend-

6.1 Calculation of Harmonic Currents. Harmonic current amplitudes are a function of the delay angle (a)and the commutating reactance (Xc). The basic equations for calculating the amplitude are given in [ 11 ? Curves showing the changes in amplitude as a function of a and X , are contained in [ 2 ] . Typical values for harmonic analysis are shown in Table 1. Theoretically, a 12-pulse converter does not produce 5, 7, 1 7 and 1 9 harmonics; but due to unbalances, some will be present. Reference [ 21 recommends the assumption that these har'Numbers in brackets correspond t o those in the References, Section 3.

22

-

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

-

F

TRANSFORMER T R A K S -

11

-vh

=I

ZC I

hf ISSIOIi LINE

Zf

FILTER AND OTHER PARALLEL LOADS

t

-

ent. The remainder varies with the square of the frequency. The no load (core loss) constitutes between 15% and 25% of the total loss and, depending upon flux density, the loss varies as frequency t o the three halves (f") power t o the frequency cubed ( f 3 ) . From this, with reactance increasing directly with frequency (inductance constant), it can be seen that the harmonic X / R ratios will be less than the fundamental frequency X / R ratio. If fundamental frequency X / R ratios are used, there will be less damping of the high-frequency current than in actuality. 6.2.2 Adjacent Capacitor Banks. If there are large capacitor banks or filters connected t o the utility system, it is necessary t o consider their effect. 6.2.3 Converter as a Harmonic Generator. The converter is usually considered to be a generator of harmonic currents ih, and is considered to be a constant current source. Then 2, is very large and is ignored. If the converter is a constant voltage source, 2, should be included. 6.2.4 Circuit Analysis. Using Ohm's and Kirchhoff's laws, the following is evident:

Define two ratios as follows:

Then Eq 3 and Eq 4 become: (Eq 7)

If

(Eq 8)

= PfIh

Because of Eq 1 , it is evident that PS+Pf = 1

(Eq 9)

Note that ps and pf are complex quantities. At the various harmonics, Eq 7 shows that it is desirable that p, be small. Typical values for a series tuned filter are (at the tuned frequency):

p,

=

0.045 1-80.6"

pf = 0.994 /+2.6" Parallel resonances occur between Zf and Z,, and typical values are:

Let

p, = 16.67 1-92.9'

2, = z,+ 2, Ih

4 = PsIh

=4

+ If

IfZf = I,Z,

pf = 16.75 /+83.6' (Eq 1)

The approximate 180° difference emphasizes why a parallel resonance cannot be tolerated at a frequency near a harmonic current generated. A current of the resonance frequency will excite the circuit and a 16.67 per unit current will oscillate between the two energy storage units (system inductance and capacitors). A plot of p, versus h is a useful display of filter performance. Frequently a plot of log p, is more convenient.

(Eq 2)

Solve Eq 2 for If,substitute into Eq 1,and rearrange, giving:

23

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

The harmonic voltage V, is:

three-phase full-control converter bridge. The thyristors operate in pairs t o convert threephase ac t o dc by switching the load among the various thyristor pairs 6 times per cycle. During the process, a brief short-circuit produces a notch in the line-to-line voltage waveform. The current in the converter of Fig 1 5 has been flowing from Phase A through thyristor 1. When thyristor 3 fires (Fig 16(a), (b), and (c)) at time t (30' on the line-to-line voltage base), the current begins to transfer from Phase A t o Phase B. Source reactance prevents instantaneous transfer: the commutating time (angle) required becomes the notch width ( p ) . The resulting notch is shown on a line-toneutral basis in Fig 16(a) and on a line-to-line basis in Fig 16(b). The latter clearly illustrates the shorting action when both thyristors 1and 3 are conducting simultaneously; the other notches reflect the action of the thyristor on the other legs of the ac circuitry. 6.4.1 Notch Area Calculations. The area of the notch is dependent upon the volt-seconds absorbed in the circuits from the source to the point of the circuit which is of interest. The area of the notch is an indication of the effect the static power converter will have on other loads. The notch area is calculated (refer t o Fig 17) as follows:

The distortion factor is: sum of squares of amplitudes of all harmonic voltages square of amplitude of fundamental

1

x 100% (Eq 11)

6.3 Telephone Interference. T w o equations are in general use in North America. 6.3.1 Voltage Telephone Influence Factor. The voltage telephone interference factor VTIF is :

where

V, = fundamental L-N voltage (rms) Ih= harmonic current into power system &=power system impedance at harmonic order h Th = telephone interference weighting factor (TIF) [1960 curves currently in use] hh = upper limit of harmonics, 5000 Hz

6.3.2 I*T Product. The other equation frequently used is the 1.T product:

6.4 Line Notching Calculations (For LowVoltage Systems). Figure 1 5 shows a typical

Fig 15 Three-phase Full Wave Converter SOURCE REACTANCE m

XL

A

m

B

m

C

3 PHASE F U L L WAVE RECTIFIER FI RING 1

5

3

24

ORDER:

1, 2 , 3 9 4 , 5 , 6

.

IEEE

COMPENSATION OF STATIC POWER CONVERTERS

Std 519-1981 LINE N E U T R A L VOLTAGE

I

NOTE: The two other phases are similar to A-B. Width of notches is exaggerated and ringing omitted for clarity.

Fig 16 Voltage Notches

LL

Lt

LC r----

- - - -I

CONVERTER OTHER LOADS

Fig 17 Inductance Diagram 25

IEEE

Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

where VN = notch depth in volts (L-L) of the deeper notch of the group tN = width of notch in microseconds Id = converter dc current in amperes e = instantaneous voltage (L-L) just prior t o notch L = inductance in henrys per phase AN = notch area in volt-microseconds

6.5.1 Relationship Between Line Notching and Distortion Factor (See Figs 16 and 17).

Combining the above equations:

6.4.2 Calculation of Source Inductance, Transformer Inductance (600 V and below). Dry type transformers used in converters at this voltage have approximately equal reactance and resistance when considering the transient characteristics of the commutating phenomena. The following equation can then apply: transformer 2 EL inductance fi28f'fi11

P

From the above:

For fi

DF-

%

See 6.4.1 for other terms.

6.6 System Calculated (Low Voltage, Below 1000 V). A typical plant distribution system is shown in Fig 18(a) and a simplified diagram in Fig 18(b). The system can then be considered an RLC circuit. Since the rectifier can be considered a short circuit, during commutation, this can be replaced by a knife switch in the simplified circuit. The equivalent impedance of the transformer needs t o be considered when the simplified sketch is drawn up. 6.6.1 System Damping Factor. In most systems, the rectifier transformer plus line impedance is much larger than the distribution transformer impedance so that the distribution transformer can be neglected in calculating the damping factor and the natural frequency. In a series resonant circuit the following equations can be employed :

6.5 Distortion Factor. The distortion factor is used t o define the effect of harmonics on the power system voltage. It is used in low-voltage, medium-voltage, and high-voltage systems. It is expressed as a percent of the fundamental and is defined as: sum of the squares of of all harmonic voltages square of the amplitude of the fundamental voltage

= 0.0744 P

where p = t h e ratio of the total inductance to the common system inductance fi = power circuit frequency VH = sum of harmonic voltages

The above assumes XL= RL 6.4.3 Calculation of Line Inductance. Typically the per-phase line inductance on a threephase ac line can be considered t o be 0.3 pH per foot of line, or about 1pH/m.

=(

60 Hz and EL = 460 V

Henrys

where 2 =transformer nameplate per unit impedance EL = rated line-to-line voltage Il = rated ac full load f = line frequency

DF

=

x 100%

Damping factor = E

See Section 4 for harmonics.

26

.

IEEE COMPENSATION OF STATIC POWER CONVERTERS

1

Std 519-1981

UTILITY DISTRIBUTION TRANSFORMER

T1

$

TRANSFORMER

CAPACITOR

CONVERTER

THYRISTOR CONVERTER

r

RT2

Fig 1 8 Typical Power System and Equivalent Diagram

-.

Natural frequency f

=

information t o size a cost saving power capacitor. Utility company rate clauses differ with respect t o reactive power so that each must be studied and evaluated on an individual basis. Detailed knowledge of the operating mode of the individual drives in a group may be used t o establish a target value of kvars t o add for reactive compensation. Each drive kW and kvar value is derived from load and speed characteristic data, taking into account basic variations in operating mode. Summation of these kW and kvar values along with similar data for other loads will provide an overall basis upon which t o size supplemental kvar requirements. If the converters are used for purposes other than motor drives, similar considerations will be required for the loading in each case. Below is an example illustrating this approach, which is based upon loading in a particular plant. For conciseness, the actual plant loading is consolidated in this listing.

lk 2~'F

Natural frequency o,=

rad/s

Lc Hz

For low-voltage equipment, the damping factor of the system should be greater than 0.5 when the natural frequency of the system is less than 2100 Hz (35 harmonic on 60 Hz). At frequencies greater than 2100 Hz, the system losses, such as skin effect, provide damping t o the system.

-

6.7 Power Factor Improvement Calculation. Because reactive power varies on a given thyristor motor drive depending upon operating speed and torque, requirements may increase more than 100% from top speed down t o low speed. N o single capacitance value can be applied t o a single drive t o maintain near constant reactive power throughout its operating range. However, a group of such drives may, by their diversity, reflect a more uniform kilovar requirement. Recording wattmeter and varmeter data obtained over a representative period of time would establish the feasibility of applying nonswitched capacitors for power factor improvement of the thyristor drive group. In many cases utility company billing (from which power, real and reactive, and power factor (PF) may be derived) will provide this

Induction motors: 1200 kW at 0.80 PF = 900 kvars 900 kW at 0.70 PF = 918 kvars Thyristor dc drives: 600 kW at 0.70 PF = 612 kvars 1100 kW at 0.50 PF = 1905 kvars Other: 1300 kW at 0.90 PF = 630 4965 kvars 5100 kW

27

IEEE

Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

5100 kW kvar

(

=

0 4 C , 5100

(

= r,loc,

05Q,

5,';f;X

= 0.7165

=

095

ixsiw:i) I X J . \ D

ACTUAL LOAD

Fig 1 9 Power-ReactiveTriangle for Power Factor Correction Figure 1 9 illustrates the low power factor (0.7165) associated with this load and that an added 3289 kvars are necessary t o improve the power factor to 0.95. The amount of reactive compensation, will depend upon the economics of compensation with regard t o utility company billing. A given rate structure may make compensation to unity power factor economical. A 3300 kvar capacity bank is easily made up of standard units. Assuming such a bank is applied in a plant on a 4160 V supply bus, fifth harmonic resonance will occur if the short circuit capacity is approximately 80 MVA. Similarly, 7 harmonic resonance will occur at approximately 150 MVA. Depending upon the actual system short-circuit level or experience, or both, a tuning reactor may be required. If required, it should be selected for 5 harmonic suppression. Changing the capacitor size can control the resonance point. The tuning reactor is sized t o take into consideration the actual capacitor bank kvar, which averages up t o 5% above the nameplate. The capacitor reactance (Xcw fundamental frequency) is : kV2 =

=

per phase and a current carrying capability at least equal t o that required by the capacitor. The question sometimes arises as to the effect that power capacitor banks have on the response of the converter. No adverse effect on response time should be expected as long as harmonic resonance is not present at a characteristic harmonic. Actually, a power capacitor bank does stiffen the ac power system transient response which would theoretically enhance response time. Practically speaking, such effect is negligible.

7. Measurements Techniques for measuring the extent and effect of harmonics and reactive compensation are readily available. They differ from ordinary power system measurement techniques primarily in the bandwidth required. Whereas most of the ordinary measurements of voltage, current, and power can be accomplished with attention t o a narrow band of frequencies near the distribution frequency (for example, 50 Hz or 60 Hz), measurement of the effect of harmonics requires attention to a substantially wider bandwidth. For most applications this bandwidth is limited to radio frequencies up t o 30 kHz. (The extremely rare situation where the minuscule radio frequency powers generated by converters is of interest will be ignored in this treatment. Applicable techniques are those of this guide extrapolated to the frequency band of interest.) In general, it is desired to measure the effect of converter operation on the remainder of the

4.16* (3.3) (1.05)

4.99 52

where

Xr= reactance of tuning reactor 1.05 = tolerance of capacitors Thus, the tuning reactor should have 0.20 !2

28

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

I

-

distribution (or transmission) system. Figure 20 represents a generalized approach to this measurement. In Fig 20 it should be noted that the ac supply may be single or three phase. The apparatus under test is a power converter, but may include transformers, inductors, capacitors, switches, etc, which are either necessary to the function of the converter or have been added to reduce the effect of the converter on the remainder of the power system. Potential transformers may or may not be required, depending on the supply voltage and the nature of the voltage coupler. Generally, voltages higher than 480 V require either a transformer or voltage divider to allow safe operation of the measuring instruments. The current transformer may in most cases be replaced with a noninductive shunt, if circumstances indicate the desirability of doing so. Voltage coupler and current coupler may be simply suitable conductors, or they may be networks, amplifiers, etc added t o allow measurement by a given instrument. In many cases, the couplers are either an accessory of, or built into, the measuring instrument. Some measurements, specifically those involving wattmeters, will require both voltage and current inputs, rather than one or the other as implied by Fig 20. The discussions of specific measurement requirements below are organized to correspond to the topics discussed in Section 8.

most interest where it can be most pronounced, that is, on distribution systems of 600 V or less. Voltage dividers and current shunts are frequently used, rather than transformers. In the lower voltage systems, these quantities can be coupled directly t o the instruments. To measure the notch width and depth, an oscilloscope is required. It is desirable that the oscilloscope have single sweep and storage capability so as t o assure cleanly defined notch areas which can be measured after the event has been recorded. Photographic records are also desirable, t o allow comparison of conditions before and after compensating techniques have been applied. The oscilloscope must be moderately wide-band, say 25 MHz, t o allow suitable fidelity of measurement. The voltage divider probe available as an accessory t o the oscilloscope normally suffices as a voltage coupler. Differential input is preferred, in order to avoid grounding problems. Operation of the oscilloscope with chassis ungrounded or floating constitutes a serious safety hazard, and should be avoided? Measurement of notch width and depth can be made by scaling the 3The Tektronix 7313 oscilloscope with 7A13 vertical amplifier and P6007 probes is adequate for most measurements on industrial systems up to 1500 V. (Note that the mention of specific manufacturers' model numbers here and later are intended to be for example only. In each case there are many other suitable measuring schemes which will be apparent to those skilled in the art.)

7.1 Line Notching. This phenomenon is of

Fig 20 Test Circuit for Measuring Current and Voltage Using Potential Transformer and Current Transformer

APPARATUS UNDER TEST

29

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

time duration and voltage excursion of the individual notches from the oscilloscope trace. When planning the installation of a converter in an existing distribution system, it is necessary to determine the Thevenin equivalent of the power source as seen by the converter input. This knowledge allows a prediction of the extent of probable uncompensated notching, and determines the extent of compensation required. The Thevenin source may be known or deduced from existing data in most cases; in some cases it may be necessary t o make some measurements to determine it. The measurements are those of no load voltage and voltage and current with a known load. It is normally desired to know the phase angle between voltage and current, as well as their absolute values. An ac industrial analyzer accurate t o 1% is sufficient for measurements of this type. Potential transformers or current transformers are not required for voltages up t o 600 V or currents to 125 A? In higher voltage systems, the notching phenomenon becomes less pronounced and more difficult t o measure accurately by observation of an oscilloscope trace. In these cases, measurements of harmonic voltages and currents are made, as described below. 7.2 Harmonics. Measurements of harmonic currents and voltages are made to determine total harmonic distortion which can be used as a figure of merit to describe the effect of the converter(s) on the distribution system. A similar figure of merit called TIF (telephone influence factor) can also be determined. TIF measurements have had substantial engineering attention in the past, meriting a separate paragraph below for discussion. Measurements of the individual harmonics are desirable to aid in selecting suppression techniques, inasmuch as the amplitudes actually generated frequently differ considerably from those indicated by simplified theory. A primary consideration in measuring harmonics is the provision of suitably wide-band sensors and instruments. Frequencies up to 6 ~

4The Weston Model 639 AC Industrial Analyzer is sufficiently accurate (1%) for most measurements of this type. For higher voltage systems, instrument transformers, such as the Weston Model 327 for current and Westinghouse Type PTM for voltage, may be used. These are relatively narrow bandwidth transformers, suitable for Thevenin measurement, but not generally suited for faithful measurements where harmonics are present, as in the case of notch measurement previously described.

kHz are usually of interest, and in some cases even higher harmonics may be of concern. The bandwidth of interest in a given case depends on the susceptibility of apparatus in the specific distribution system. Generally, the commonly available line frequency sensors and instruments, such as those used for system operation, are not suitably broadband? No special voltage or current couplers are required for harmonic distortion measurements. Good practice would include the use of either coaxial cable or shielded twisted pair conductors between voltage and current sensors and instruments. Current transformers will require suitably noninductive resistor burdens as recommended by the transformer manufacturer.

7.3 Telephone Interference. The measurement of TIF may be accomplished in two ways. The first involves the use of a current transformer and a frequency-selective voltmeter! Using this method the individual harmonics are recorded, the appropriate TIF/C Message Weighting applied and the individual weighted harmonics summed on a root-mean-square basis. This method has the advantage of identifying particular harmonics which could be suppressed by filtering or other means. The second method involves a direct measurement? The details of the measurements are 'To measure total harmonic distortion directly, a distortion analyzer, such as the Hewlett-Packard Model 331A, may be used. This instrument may also be used, in its voltmeter mode of operation, to read amplitudes of individual harmonics, though not as accurately as might be done with a frequency-selective voltmeter designed for that purpose. The advantage of the distortion analyzer is that it indicates the total harmonic distortion directly. As an alternative, a frequency selective voltmeter, such as the Hewlett-Packard Model 3590A, can be used to measure the amplitude of the fundamental and each of the harmonics. The total harmonic distortion can then be calculated. To use either the distortion analyzer or frequency-selective voltmeter, system voltages and currents must be divided or transformed to levels compatible with the instruments' allowable input levels. Wideband current transformers, such as the Pearson Model 301X, and voltage dividers, such as the ITTJennings Model JP-2000, may be used for this purpose. Normally, harmonic distortion is measured on either voltage or current, but not both. Most practitioners favor the voltage measurement, probably because voltages are generally more accessible for sensing. 6Examples of a frequency-selective voltmeter are the Hewlett Packard Model 302A or Wilcom Products Model T132 analyzer. 7A Western Electric 106A current coupling unit is connected t o a Western Electric 3 Type noise measuring set or alternatively a Hewlett Packard Model 3555 transmission measuring set.

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

_-

-

given in ANSI/IEEE Std 368-1977 [21] and IEEE Std 469-1977[22]. TIF measurements are applicable to telephone circuits which are voice frequency and involve electro-acoustic transducers. There are an increasing number of telephone services which do not benefit from the C Message weighting (for example, data circuits) and others which operate above the voice band (for example, carrier system) which have the potential for interference from power lines. For these situations unweighted single frequency measurements must be taken and the results analyzed t o predict interference levels.

however, should be mentioned. When power factor correction networks are installed, it is frequently required that the harmonic currents into the networks be measured. This is necessary t o assure that components of such networks are being utilized within their rating. Since these are harmonic currents, the techniques and instruments discussed in 7.2 are applicable.

7.4 Flicker. The measure of flicker is the frequency and severity (amplitude) of voltage variation. Unlike most of the measurements discussed herein, this is a narrow band measurement. It can be made with instrument transformers normally used in the distribution system and needs no special voltage coupler. Where the phenomenon is periodic or nearly periodic, the measurement can be made with a voltmeter and a stop watch, or in the case of periods shorter than a few seconds, an oscilloscope or oscillograph. Some care should be taken t o ensure that instrument damping (or lack of it) does not distort the measurements. Where the phenomenon is nearly random, and specifically where it is desired t o establish statistics over periods longer than a few hours, an event recorder may be used?

Industrial and commercial application of converters can be divided into two broad categories :

8. Recommended Practices

(1)Large drives and electrochemical processes operated from a medium-voltage (2.4-69 kV) or high-voltage (above 115 kV) power source (2) Small drives and miscellaneous power supplies operated from a low-voltage (below 600 V) source The effects on both systems are similar. Analysis follows the same procedure. The XIR ratios are higher in medium-voltage systems, so the resonant phenomenon is less damped. The notching phenomenon is more important in low-voltage systems. This section includes discussion and the recommended practices for: (1) Line notch limits (2) Voltage distortion limits (3) Telephone influence limits (4)Flicker limits Part of the discussion is how these limits can be met by good design

7.5 Power Factor Correction. The measurements required for power factor correction are the sort of measurements normally made within the distribution system. That is, ordinary measurements of voltage, current, and power at 50 Hz or 60 Hz are those required. The object in applying power factor correction techniques is t o increase the ratio of real power t o volt-amperes as viewed from the utility source. This can be done by utilizing instruments and measuring techniques used for system cost metering and operation. These are well-known and established and need not be described here. One aspect of the application

8.1 Line Notching. Line notching occurs when current commutates from one phase t o another. During commutation these two phases are connected (short circuited) by the converter through the ac impedance (which is very low) and thus causes the voltage t o drop t o near zero (Fig 21). These line notches can excite the natural resonance of the power distribution system in the audio (15 to 20 000 Hz) frequency range. The higher frequencies are easily filtered with resistor capacitor networks if any problem arises. The energy associated with oscillations excited by commutation notches is small. Many converters are designed to use a single

~~

-

'For example, the Dranetz Model 606 Power-Line Disturbance Analyzer will afford a printed record of voltage excursion amplitudes versus time of occurrence. This allows the flicker statistics to be recorded without operator attendance, a useful attribute when event occurrences are randomly separated by several minutes or even hours.

31

IEEE

Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

BUS A

(,BUS B

SWITCH

(

THYRISTOR CONVERTER

BUSC

Fig 21 Notch Depth Reduction pulse t o gate the thyristor. If the line notch is wider than the gate pulse, the thyristor may not continue in conduction and the converter will suffer a commutation failure if in the inverting mode. stability may be affected if in the rectifying mode. Other equipment, such as digital equipment, may also be affected. Line notching is particularly evident in lowvoltage systems. The discussion that follows is written for low-voltage systems or systems where the X/R ratios are low, below 6. Values given are typical. 8.1.1 Design Practices for Minimizing Notching Effects. Line notching and its effects are directly affected by the plant distribution system, the power and control wiring, and the

design of the gate firing pulse. A discussion of recommended practices follows. 8.1.1.1 Distribution System. The impedance as seen by a converter includes the power source (utility system), stepdown transformer, cables, and isolation transformer. The isolation transformer represents the largest single impedance. Figure 22(a) represents a typical distribution system. The incoming voltage is stepped down t o plant utilization voltage, EL,by the main transformer. Power then flows through the line isolation transformer t o the converter. Voltage EL distributes power t o other equipment. Figure 22(b) shows the equivalent system impedance diagram. 2, and Z, are the impedances

Fig 22 Simplified Diagram, Power Distribution System (a)

(b) SYSTEM AND MAIN TRANSFORMER

TRANSFORMER

PLANT BUS EL VOLTS

ISOLATION TRANSFORMERS

ISOLATION TRANSFORMER

t OTHER LOADS

OTHER LOADS

CONVERTER

32

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

~

-.

4

76 Notch Depth = ____

100

&+Z,

=K i

-

other circuits at the point of common coupling. 8.1.1.2 Power Wiring Practice. The power wiring t o the converter equipment should be isolated from control wiring to minimize the inductive capacitive coupling between the two. The sharp wave fronts of the notches and currents present on the power wiring can induce noise on adjacent circuits. If an isolation transformer is provided, it should be placed as close as possible to the converter. 8.1.1.3 Design of Gate Triggering Circuit. Since line notching cannot always be avoided, the gate triggering pulses on industrial equipment should have such design criteria that interference is not encountered in most applications. As a recommended practice, equipment should be designed so as t o be capable of performing on supply systems containing notches of 250 ps wide (5.4 electrical degrees) and a notch depth of 0.7 of the rated maximum line voltage. 8.1.2 Limits of Line Voltage Notching. Three classes have been established on low-voltage systems to determine the limits of distortion that may be allowed from static power converters. The criteria for measurement in these systems include:

of the main and isolation transformers, respectively. The junction of impedances Z,and Z, is the plant bus which carries line voltage ELand distributes power throughout the building. During commutation the voltage on the load side of the isolation transformer goes to zero. However, the short circuit is isolated from the plant bus by the transformer impedance so that the effect of the notch on the plant bus is greatly diminished. The amount of notching that gets through to the plant bus can be computed by analyzing the equivalent circuit voltage divider formed by the transformer impedances. It can be shown that the line notch amplitude at the bus is:

100

If there is no isolation transformer, Z,is zero, and there will be no impedance drop between the converter and the bus so the voltage will drop t o zero momentarily. Figure 23 illustrates good and bad practice, respectively. Figure 23(b) has the converter sharing the same lines as other equipment, allowing ready propagation of the harmonic currents throughout the system. Figure 23(a) minimizes the effect of the converter on other loads in the power system. Impedance inserted into the converter circuit lessens the depth of the notch as seen by the

DF = voltage distortion factor

AN =area of the commutation notch in voltp

microseconds =impedance ratio of total impedance t o impedance at common point in system

Fig 23 Converter Connector to Distribution System (a) Recommended Configuration; (b) Poor Practice UTILITY SYSTEM TRANSFORMER

@I

CONVERTER

OTHER LOADS RECOMMENDED CONFIGURATION

POOR PRACTICE

(b)

(a)

33

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

Table 2 Low-Voltage System Classification and Distortion Limits for 460 V Systems Class Special Application* General System Dedicated System

p

10 5 2

AN voltmicroseconds 16 400 22 800 36 500

high impedance to current at the resonant frequency. Series resonance is low impedance. If the parallel resonance is at or near one of the characteristic harmonic frequencies produced by the converter, the tank circuit can be excited and large oscillating currents can flow between the inductive reactance of the power system and the capacitive reactance of the capacitors. These currents add t o the harmonic voltage drop, causing a much larger voltage distortion factor. It is this resonant condition that causes problems involving conductive and inductive interference. Hence, capacitors should be sized t o avoid a resonance near a characteristic harmonic frequency. The parallel resonant frequency can be calculated as:

DF %

3 5 10

*Special applications are those where the rate of change of voltage of the notch might mistrigger an event.

For notch area (AN) the voltage and current are referred t o the point of common coupling. The dimensions are expressed in voltmicroseconds which are easily measured on an oscilloscope screen.

f,

8.2 Power Factor Correction. The question of whether or not t o apply one or more of the power factor correction techniques noted in 5.2 is almost entirely answered by the economics of a specific converter installation. The recommended practice is then simply t o use power factor correction t o the degree economically justifiable. However, there are two caveats involving the use of capacitance. These are the system sink phenomenon and the resonant phenomenon, described below. 8.2.1 System Sink Phenemenon. Power factor correcting capacitors are placed across the utility’s transmission system, frequently with very little isolating impedance. As a consequence, any harmonics present on the incoming voltage are imposed on the capacitors. Thus, the capacitors can be subjected t o large harmonic currents, generated elsewhere in the power system, in some cases sufficient t o destroy them. Prudence dictates a preliminary measurement t o determine the existence and degree of such harmonics. If they exist t o a substantial degree, either the capacitors must be decoupled (with resistance or inductance in series) or the power factor correction effort abandoned. 8.2.2 Resonant Phenomenon. When static capacitors are connected t o a system for voltage or reactive power control (power factor correction), there is a frequency at which the capacitors are in parallel resonance with the power system reactance. Figure 24 illustrates this when the converter is considered a source of harmonic currents. Parallel resonance is a

system short circuit MVA capacitor Mvar

= fl

where

X,

= reactance

of capacitor bank, per unit or

i2

zc= reactance

of power system, per unit or

i2 fi

=

L,, C

= =

fundamental frequency inductance of power system, H capacitance of capacitor bank, F

8.3 Harmonics. The harmonic voltage drop caused by the flow of harmonic current through an impedance distorts the fundamental sine wave of voltage (see 5.3). This voltage distortion causes harmonic currents t o flow in circuits other than those which normally have converter loads. These currents can have a conductive effect in the circuit in which they flow Fig 24 Power System Showing Paralleling Between System and Shunt Capacitance Reactance SYSTEM REACTANCE

34

_L

SHUNT

IEEE COMPENSATION OF STATIC POWER CONVERTERS

Std 519-1981

UTILITY

Fig 25 Power System with Shunt Filters

-

sum of Ih of all converters connected H = harmonic t o which the filter is tuned (tuned harmonic)

or an inductive effect on circuit conductors which parallel the circuit conductor. 8.3.1 Shunt Filters. The application of a shunt filter to a power system is effective t o remove harmonics generated by solid-state converters. When connected t o the converter bus, the flow of harmonic current is so controlled that the harmonic voltages in other parts of the circuits are very low. Figure 25 shows a typical arrangement. Because the filters will absorb almost all of the harmonic currents generated by the converter, the filter must be sized t o take these currents, as well as any other currents not isolated from the filter with impedance. 8.3.1.1 Filter Rating. The capacitor in the filter must be of such a rating as t o enable it to withstand the arithmetic sum of the fundamental and tuned harmonic voltages in the filter. (See Fig 26.) The voltage and current ratings of the reactor and capacitor are then:

Ih =

Vc = Ii X ci + IHX CH VL = 11XL, 4- IH x L ~ The volt-ampere rating of the capacitor is then: IF Vi Under maximum conditions (system voltage above normal or overload on the converters), the volt-ampere loading of the capacitor cannot exceed 1.35 per unit with a maximum of 1.1per unit V. (See ANSI/IEEE Std 18-1980.) Table 3 lists the filter configuration for different size power systems. Other factors t o be considered are capacitor size for reactive comFig 26 Shunt Power Filter

'fi vs

XL

h

where

xc T

I

V,= system nominal voltage (fundamental) 35

vc

f

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

Table 3 Typical Filter Configuration Versus System Size

where vh = Ih

System Short-circuit Capacity 0 - 250 MVA 251 - 750 MVA 751 1500 MVA 1500MVA

-

&

V, = fundamental voltage H = 50 or any harmonic less than 0.01 V,

Tuned Filter 5th 5th. 7th 5th; 7th, 11th 5th, 7th, l l t h , 13th

Theoretical values of distortion factors are plotted in Fig 27 for different pulse number converters as a function of the ratio of system impedance t o converter size (short-circuit ratio) where:

pensation, number of capacitor equipments, local factors influencing choices, and the total converter load on the power system. 8.3.1.2 Parallel Resonances. For each tuned filter there will be a parallel resonance between the filter and the power system reactance. This parallel resonant point will be lower than the filter frequency and above the next lowest tuned filter. For this reason, it is not practical t o apply filters tuned t o the higher order harmonics and not t o the lower orders. For example, if an 11 harmonic filter is applied on a normal twelve-pulse rectifier, the parallel resonant point will be below the 11 harmonic. If this is a t the 7 harmonic, any 7 harmonic current flowing into the high impedance at the parallel resonance will cause high 7 harmonic oscillating currents between the 11 harmonic filter and the power system. This condition will overload the capacitors in the filter, causing fuses t o fail and detuning the circuit. Therefore, filters should be applied and connected t o the power system starting with the lowest order and added upon. Conversely, if the total kvar of capacitance must be reduced, the highest order filter should be switched off first, etc. Once filters are connected t o the system, there will be a low impedance path for the currents of the tuned frequencies. If there is a harmonic component of voltage in the power supply system corresponding t o the filter frequency, this harmonic voltage will cause additional current in the filter. 8.3.2 Limits on Harmonics. The amount of voltage distortion that can be tolerated on a power system is dependent upon the equipment connected t o it and this equipment’s susceptibility t o nonsinusoidal wave shapes. The distortion is a function of the amount of harmonic currents flowing through the impedance t o the source.

Short-circuit Ratio =

system short-circuit MVA converter MW

On industrial power systems, the voltage disnot be greater than listed in tortion 4-

If voltage distortion is kept within the above limits, other equipment will operate satisfactorily. 8.4 Telephone Interference. The presence of harmonic currents or voltages in circuitry associated with power conversion apparatus can produce magnetic and electric fields that will impair the satisfactory performance of communication systems which, by virtue of their proximity and susceptibility, can be disturbed. For a given physical arrangement it is apparent that the disturbance is a function of both the amplitude and the frequency of the disturbing component in the conversion apparatus. The study of means for minimizing the interference which power systems might cause in communication systems is a proper subject of inductive coordination which has been actively pursued by a Joint Subcommittee for Development and Research of the Edison Electric Institute and The Bell Telephone System. Since a primary source of interference is the presence of harmonic currents or voltages in the power system, a task force of the above joint subcommittee has revised the weighing factors to be placed upon the harmonic frequency components t o bring them up-to-date with the improved state of the communication systems in 1960, following the introduction of the 500type telephone set. By subjective and objective listening tests on a group of individuals, relative weights were established for the various harmonic frequencies which indicate the disturbance t o voice frequency communication that

I H

36

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

-,.

Table 4 Voltage Distortion Limits for Medium and High-Voltage Power Systems Power System Voltage Dedicated* System General Level Converter Power System Medium Voltage 2.4 - 69 kV 8% 5% High Voltage 115 kV and above 1.5% 1.5% *A dedicated system is one servicing only converters or loads not affected by voltage distortion.

Definition of Buses for Table 4

MEDIUM VOLTAGE

CONVERTERS

CONVERTER

BUSC

MEDIUM VOLTAGE

LOW VOLTAGE SUBSTATIONS

CONVERTER LOADS

OTHER LOAD NOT SENSITIVE TO VOLTAGE DISTORTION

NOTE: Bus A is a general power system. Buses B and C are considered dedicated systems.

37

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

28

24

\\

NUMBER OF PULSES

-

-6 ---12

APPROXIMATE ALPHAS Ed

I \\

10

ff

80"

10% 100% 120%

\

20 30 SHORT-CIRCUIT RATIO

31"

-

0"

40

3

NOTE: The voltage distortion on industrial power systems should not be greater than that listed in Table 4.

Fig 27 Theoretical Voltage Distortion Versus Short-circuit Ratio for Six- and Twelve-Pulse Rectifiers the injection of a signal of the harmonic frequency into the communication network will produce relative t o that which would be produced by a 1000 Hz signal similarly injected. 8.4.1 TIF Weighting Factor. The TIF Weighting is a combination of the C Message Weighting characteristic, which accounts for the relative interferring effect of various frequencies in the voice band (including the response of the telephone set and the ear), and a capacitor, which provides weighting which is directly proportional t o frequency t o account for the assumed coupling function. TIF is a dimensionless quantity which is indicative of the waveform and not the amplitude, and is given by:

or equivalently :

TIF =

dE(q

where X, = total rms voltage or current X,= single frequency rms current or voltage at frequency f W,= single frequency TIF weighting at frequency f

38

IEEE

Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

h

The TIF weighting function, W,, which reflects the present C Message Weighting and the coupling (proportionality component) normalized t o 1 kHz, is given by:

8.4.2.1 Multiphasing of the Conversion Equipment. Increasing the number of phases or pulse number of the conversion system will generally reduce certain harmonic components in the leads t o the converter. 8.4.2.2 Residual or Ground Return Currents. Telephone circuits are particularly susceptible t o the influence of ground return currents. Special care should be exercised in holding these t o an absolute minimum. As long as both conductors of a telephone circuit have equal exposure t o a balanced three-phase power circuit, as is the case with twisted pairs, the induced harmonic voltages and currents cancel. 8.4.2.3 Commutation Effects. Presence of reactance in the utility source and reactance in the converter transformers, both of which can contribute t o the commutating reactance of the converter, will cause the I * T product and the kV-T product at the line terminals of the converter t o increase rapidly with the angle of phase retard. To minimize the inductive influence it is desirable, where practicable, t o maintain the angle of phase retard of commutation in the converter as small as possible. 8.4.2.4 Filtering. The influence of currents and voltages in the utility system caused by harmonic components in the converter can be reduced by a judicious choice of series and shunt reactive filters placed at the connecting interface between the two systems. Extreme care and caution must be exercised in the application of such filters t o avoid possible resonant conditions resulting from unexpected harmonics which might appear at some future time in the utility system causing catastrophic damage. 8.4.3 Limits of Interference. It is difficult t o place specific limits on the telephone influence which the harmonic components of current and voltage in converter systems can inflict. The actual interference t o voice communication systems in proximity t o the power system supplying the converter is dependent upon a number of factors not under the control of the designer of the converter system. These factors will vary from location t o location and from time t o time as the state-of-the art of inductive coordination progresses. There is some data available which related t o the I * Tperformance of large converters used in telephone offices t o charge batteries. It should be noted that the values shown in Table 6 are

w,=5 4f where 5 = constant 4 = C message weighting at frequency f f = frequency under consideration As an example, the TIF Weighting at 1kHz is 5000 since the C message attenuation is unity, that is: W,= (5) (1)(1000)= 5000

In practice, telephone interference is often expressed as a product of the current and the TIF, that is, the I - T product, where the I is rms current in amperes and T i s TIF. Alternatively, it is sometimes expressed as a product of the voltage and the TIF weighting, where the voltage is in rms kV, that is, the kV * T product. The single frequency TIF values are listed in Table 5. The curve of Fig 28 plots the values.

-Table 5 1960 Single Frequency TIF Values FREQ 60 180 300 360 420 540 660 720 780 900

_-

TIF FREQ TIF FREQ TIF FREQ 7820 3000 0.5 1020 5100 1860 8330 3180 30 1080 5400 1980 3300 5630 2100 8830 225 1140 9080 3540 400 1260 6050 2160 9330 3660 650 1380 6370 2220 9840 3900 1320 1440 6650 2340 1500 6680 2460 10340 4020 2260 2760 1620 6970 2580 10600 4260 3360 1740 7320 2820 10210 4380 4350 1800 7570 2940 9820 5000

TIF 9670 8740 8090 6730 6130 4400 3700 2750 2190 840

8.4.2 Methods of Reducing Interference. Where the power conversion equipment is directly connected t o a utility system, most of the interference will result from harmonic current and voltage disturbances which are placed upon the utility network by the converter. This is due t o the proximity and greater exposure which the communication circuits will have t o this network. Other exposures t o the converter interference are more closely contained within the industrial complex and their interfering effects can be held t o negligible levels by suitable placement and shielding of the wiring. The disturbance to the communications system can be reduced by the following means. 39

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

FREQUENCY

IN HERTZ

Fig 28

1960 TIF Weighting Values given for illustrative purposes and are not to be considered as requirements. Furthermore, the values shown are applicable to the secondary distribution within the telephone building and the I * T on the primary system would be reduced by the turns ratio in the distribution transformer, which is typically in the range of (40 to 60):l. Thus, an I*T of 100 000 for a 240 V, 1600 A converter would be about 2000 on the primary distribution, which, of course, is important since the exposure t o the primary feed will be greater in length. These converters were of the 6-pulse type with phase-shifting taps to permit two converters t o be operated in parallel on a 12-pulse basis or four converters t o be operated on a 24pulse basis. Recently there have been expressed desires to lower the specified maximum values t o one-half or less of the above figures, particu-

larly where the battery plant is to be associated with an electronic switching office. For the case of ferroresonant units which do not utilize phase shifting, the I * T is typically much lower, as indicated in Table 7. As discussed previously in 8.4.1,the I - T on the primary transmission is of most interest t o the telephone company inductive coordination engineer. Although there are no specific requirements, experience with interference problems over the years have provided some guidelines which may be useful. Noise sensitive installations fall in Category I. Commercial buildings and industrial plants fall in Category 11. Unrestricted areas fall in Category 111. It should be pointed out that the above guidelines are applicable t o balanced rather than residual components on power systems. Table 8

Table 6 Typical 1-T Values for 48 V DC Converters

Table 7 Typical I * T Values for 48 V DC Ferroresonant Converters

Three Phase Line-to-Line Voltage 2081240 V

Rectifier Full Load Output Current Rating 400

I*T On Secondary Distribution 25 000

480 V

800 1600 400 800 1600

100 000 12 000 25 000 50 000

Three Phase Line-to-Line Voltage (Secondary) 2081240 V

50 000

480 V

Converter Full Load output Current Rating loo* 400 loo* 400

*Single Phase Rectifiers

40

I-T On Secondary Distribution 7 50 1500

350 750

-.

COMPENSATION OF STATIC POWER CONVERTERS

Table 8 Balanced I*T Guidelines for Converter Installations, Tie (Supply) Lines

.-7

Category I 11 I11

as in the case of jogging or manual spot-welding. A source may also be periodic, as in the case of an automatic spot-welder. Flicker intensity (that is, the magnitude of the voltage variation) is determined by power source impedance and load peak power requirements. When planning t o install pulsed converters, the effects of the pulse load on other parts of the distribution system should be calculated. This requires knowledge of: (1)The volt-ampere requirements of the pulsed load, magnitude and frequency (2)The impedance of the source(s) within the distribution system back to a supply of such stiffness that variations can be considered truly inconsequential (3) Whether or not apparatus or beings susceptible to flicker are within the exposed distribution sector and their degree of susceptibility 8.5.1 Limits of Flicker. Frequently the degree of susceptibility is not readily determinable. Figure 29 is offered as a guide in planning for such applications. This curve is derived from empirical studies made by several sources [ 71 -[ 141 , There are several such curves existing which have approximately the same vertical scale. Figure 29 represents the least conservative of available curves; that is, it allows approximately three times the voltage variation considered tolerable by more conservative authorities. 8.5.2 Compensation for Flicker. Methods for compensating for existing or potential flicker are much the same as those used t o compensate for subtransient disturbances, such as those evidenced by notching or harmonic currents. The simplest and generally most effective technique is to provide a sufficiently stiff source of power so that the effect is negligible at the point where the flicker source is tapped off from the rest of the power distribution system. Compensatory methods are used t o emulate the stiff source: series capacitors, thyristor switching of inductors with shunt capacitors (static var control), saturating shunt inductors, synchronous condensers, and switched shunt capacitors may be used to maintain a relatively steady voltage at the tie point. As in cases where such schemes are used t o provide subtransient compensation, the possibility of overall distribution system instability must be thoroughly investigated before one can confidently apply the technique.

Description I*T Levels most unlikely Up t o 10 000 to cause interference Levels that might cause 10 000 to 50 000 interference Levels that probably greater than 50 000 will cause interference

NOTE: These values of I-T product are for circuits with an exposure between overhead systems, both power and telephone. Within an industrial plant or commercial building, the exposure between power distribution in cables and telephone lines in cable with twisted pairs is extremely low and no interference is normally encountered. I-T products similar to those of Table 6 should be used within plants and buildings.

provides representative I *T guidelines for electric lines which tie industrial and commercial converter installations t o primary distribution and .transmission line networks [6]. Similar 1.T guidelines for H V and EHV transmission lines were recently updated and published in ANSI/IEEE Std 368-1977 [21]. ~

--

IEEE Std 519-1981

8.5 Flicker. This phenomenon is a result of applying a load on the converter, then releasing it, reapplying it some time later, etc. The converter does not in itself cause flicker. If this process is carried out at a frequency to which the human eye is susceptible, and if the resulting system voltage drop is great enough, a modulation of the light level of incandescent or fluorescent lamps will be detected. This is the effect which gives the phenomenon its name, and one which may be a matter of concern. In modern power systems, however, there may be other apparatus, such as computers, instrumentation, and communication equipment, which suffer deleterious effects. For some cases, these deleterious effects may exist even though the flicker of incandescent lamps is not discernible. The measure of flicker is the amount of system voltage variation involved and the fiequency at which the variation recurs. The frequency may be a pure single frequency, but is more often a frequency band. Sources of flicker in industrial power distribution systems can be, for instance, the somewhat random variations of load typified by an arc furnace melting scrap steel or elevator motor starts and stops. A flicker source may be nearly periodic,

41

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

5

0

Fig 29 Maximum Permissible Voltage Fluctuations

9. Selected Bibliography on Power Factor, Harmonics, and EM1

Convertors. (see Chapter 7 in High Voltage Direct Current convertors and Systems, Ed: CORY, B. J. London: Macdonald, 1965.

9.1 Books and General Discussions [ B l ] SCHAEFER, J. Rectifier Circuits: Theory and Design. New York: John Wiley, 1965.

[B6] ADAMSON, C. and HINGORANI, N. G. High Voltage Direct Current Power Transmission. (see Chapter 10, Harmonics). London: Garraway, 1960.

[B2] KIMBARK, E. W. Direct Current Transmission, vol I. (see Chapter 8, Harmonics and Filters, which includes a list of 62 references). New York: John Wiley, 1971.

[B7] BJARESTEN, N. A. The Static Converter as a High-speed Power Amplifier. (Direct Current). London: June 1963,154-165.

[ B3] PELLY, B. R. Thyristor Phase-Controlled Converters and Cycloconverters. New York: John Wiley, 1971.

[B8] IEE CONFERENCE PUBLICATIONS. no 8, Abnormal Loads on Power Systems, 1964.

[B4] RISSIK, H. The Fundamental Theory of Arc Converters. London: Chapman and Hall Ltd, 1939.

[B9] IEE CONFERENCE PUBLICATIONS. no 22, High-Voltage DC Transmission, 1966. [BlO] IEE CONFERENCE PUBLICATIONS. no 107, High-Voltage DC or AC Power Transmission, 1973.

[B5] AINSWORTH, J. D. Filters, Damping Circuits, and Reactive Volt-Amps in HVDC

42

IEEE

Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

h

[B24] SUCENA-PAIVA, J. P. and FRERIS, L. L. Stability study of Controlled Rectifiers Using a New Discrete Control. Proceedings o f IEE, v o l l l 9 , Sept 1972, pp. 1285-1293.

[ B l l ] IEE CONFERENCE PUBLICATIONS. no 110, Sources and Effects of Power-System Disturbances, 1974. [ B12] IEE CONFERENCE PUBLICATIONS. no 123, Power Electronics - P o w e r Semiconductors and their Applications, 1974.

[ B25] LAGOSTENA, L. Disturbances Produced by Domestic Appliances Controlled by Thyristors: Experiments and Studies Conducted for the Purpose of Preparing Adequate Standards. IEE Conference Pub no 110, April 1974, pp 214-222.

[B13] IEE CONFERENCE PUBLICATIONS. no 154, Power Electronics - Power Semiconductors and their Applications, 1977. [B14] KAUFERLE, J. HVDC Stations Connected t o Weak AC Systems. IEEE Trunsactions. PAS-89, Sept 1970, pp 1610-1617.

[B26] UHLMANN, E. Power Transmission by Direct Current. Springer-Verlag, Berlin, Germany, 1975 (in English).

[B15] HINGORANI, N. G. and BURBERY, M. F. Simulation of AC System Impedance in HVDC System Studies. IEEE Transactions, PAS-89, May 1970, pp 820-828.

9.2 Real and Wattless Power [B27] CALVERLEY, T. E. The Flow of Power and Reactive Components in Rectifier and Inverter Equipments. English Electric Journal, Mar 1954, pp 206-219, and Apr 1954, pp 243259.

[B16] GAUPER, H. A. Power Supply Aspects of Semiconductor Equipment. IEEE Spectrum, October 1971, pp 32-43.

z

[B17] BARON, J. A. and REEVE, J. Harmonic Interaction Between HVDC Converters and AC Power Systems. IEEE Transactions, PAS-90, NOV1971, pp 2785-2793.

[B28] SCHMIDT, A. Power Factor of Rectifiers. AIEE Transactions, vol 77, pt 11, May 1958, pp 53-57. [B29] KIMBARK, E. W. A Chart Showing the Relationships between Electrical Quantities on the AC and DC Sides of a Converter. IEEE Trunsactions, vol PAS-82, Dec 1963, pp 10501054. Also Direct Current, vol 8, June 1963, pp 166-169.

[B18] CORBYN, D. B. This Business of Harmonics. Electronics and Power, June 1972, pp 219-223. [B19] JACOBS, A. P. and WALSH, G. W. Application Considerations for SCR DC Drives and Associated Power Systems. IEEE Transactions, vol IGA-4, July/Aug 1968, pp 396-404.

[B30] SHEPHERD, W. and ZAKIKHANI, P. Suggested Definition of Reactive Power for Nonsinusoidal Systems. Proceedings IEE, vol 119, Sept 1972, pp 1361-1362. (see also discussion in vol 120, Jan 1973, p. 108, and July 1973, pp 796-798, and vol121, May 1974, pp 389-390, and July 1974, pp 705-706.

[B20] STACEY, E. M. and SELCHAU-HANSEN, P. V. SCR Drives - AC Line Disturbance, Isolation, and Short-circuit Protection. IEEE Transactions, vol IA-10, Jan/Feb 1974, pp 88105. [B21] WHITEHEAD, S. and RADLEY, W. G. Generation and Flow of Harmonics in Transmission Systems. IEE Journal, vol 96, pt 11, 1949, pp 29-48.

[B31] SHARON, D. Reactive-Power Definitions and Power-Factor Improvement in Nonlinear Systems. Proceedings IEE, vol 120, June 1973, pp 704-706. (see also discussion in vol 121, May 1974, pp 390-392, and July 1974, pp 705-706.

[B22] MELVOLD, D. J. Pacific HVDC Intertie System AC Side Harmonic Studies. IEEE Transactions, vol PAS-92, Mar/April 1973, pp 690-701.

[B32] ERLICKI, M. S. and EIGELES, A. E. New Aspects of Power Factor Improvement: Part I - Theoretical Basis; Part I1 - Practical Circuits. IEEE Transactions, vol IGA-4, July/ Aug 1968, pp 441-455.

[B23] COLLIE, A. A. Solid-state Control of Domestic Appliances. IEE Electronics and Power, Jan 1972, pp 19-22. 43

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

9.3 Waveform Analysis and Measurement Techniques [B33] GOODHUE, W. M. The Rectifier Calculus. AIEE Transactions, vol 59, 1940, pp 687691 and pp 1073-1076.

no 110, April 1974, pp 261-267. 9.4 Standards and Engineering Recommendations [ B44] Supplies t o Converter Equipment-Harmonic Distortion and Permissible Pulse Number of Consumers’ Rectifiers and Inverters (British) Electricity Council Engineering Recommendation G5/2, Oct 1967.

[B34] GIBBONS, J. F. A Simplified Procedure for Finding Fourier Coefficients. Proceedings IRE, vol 45, Feb 1957, p 243; (see also discussion on pp 1018-1019 and pp 1022-1024, July 1957; p 1549, Nov 1957; and vol46, Nov 1958, pp 1877-1878.

[B45] Limits for Harmonics in the United Kingdom Electricity Supply System, System Design and Development Committee The Electricity Council (Britain), Recommendation G.5/3, Sept 1976.

[B35] GUILLEMIN, E. A. Computational Techniques Which Simplify the Correlation Between Steady-State and Transient Response of Filters and Other Networks. Proceedings National Electronics Conference, vol 9, 1953, pp 513-532.

[B46] Report on Harmonic Distortion Caused by Converter Equipment, British Electricity Boards A.C.E. Report no 15,1970.

[B36] AMATO, C. J. A Simple and Speedy Method for Determining the Fourier Coefficients of Power Converter Waveforms. IEEE Industry and General Application 4th Annual Meeting Record, Oct 1969, pp 477-483. Reprinted in Power Semiconductor Applications, vol11, New York; IEEE Press, 1972, pp 44-50.

[B47] KIDD, W. L. and DUKE, K. J. Harmonic Voltage Distortion and Harmonic Currents in the British Distribution Network, Their Effects and Limitation. IEE Conference Publications no 110, April 1974, pp 228-234. [B48] DELOUX, G. International Standardization and Electric Power Supply Network Disturbances. IEE Conference Publications no 110, April 1974, pp 223-227.

[B37] DORTORT, I. K. Harmonic Analysis by Direct Area Measurements. AIEE Transactions, V O ~75, pt 11,1956, pp 16-19.

[B49] GAUPER, H. A. Regulatory and Industrial Aspects of Power Conversion Interference. IEEE Industrial Static Power Conversion Conference Record, (Catalog no 34C20), 1965, pp 109-111.

[B38] LEVENSTEIN, H. Fourier Coefficients and Such. IEEE Spectrum, Aug 1966, p 5. [B39] COREY, P. D. Methods for Optimizing the Waveform of Stepped-Wave Static Inverters. AIEE Conference, June 1962, Paper 62-1147. Reprinted in Power Semiconductor Applications, IEEE Press: 1972, vol I, pp 321-327.

[ B50] Specifications for Semiconductor Rectifier Equipments, British Standard 4417. [B51] Electromagnetic Interference Characteristics, Requirements for Equipment MIL-STD461. Measurement of Electromagnetic Interference Characteristics, MIL-STD-462. Definitions and System of Units, Electromagnetic Interference Technology, MIL-STD-463.

[B40] DORTORT, I. K. Phase Shifting of Harmonics in AC Circuits of Rectifiers. IEEE Trunsactions, vol IGA-4, Nov/Dec 1968, pp 655-658. [B41] STANTON, K. N. Instrumentation for Thyristor Control. IEEE Transactions, vol IGA-4, Nov/Dec 1968, pp 638-643.

[B52] Semiconductor Dimmers for Incandescent Lamps, NEMA WD-2-1970.

[ B53] Load Control for use on Central Electric Heating Systems, NEMA Pub 101-1971 and EEI Publication 71-43.

[B42] DOWNING, W. C. Watthour Meter Accuracy on SCR Controlled Resistance Loads. IEEE Transactions, vol PAS-93, July/Aug 1974, pp 1083-1089.

[B54] Directives Concerning the Protection of Telecommunication Lines Against Harmful Effects from Electricity Lines. International Communication Union, Geneva, 1963, pp 414.

[B43] BAGGOT, A. J. The Effect of Waveshape Distortions on the Measurement of Energy by Tariff Meters. IEEE Conference Publications 44

IEEE COMPENSATION OF STATIC POWER CONVERTERS

h

Std 519-1981

9.5 Waveform Analysis and Means for Harmonic Suppression/Power Averaging 9.5.1 Converter Waveform Analysis [B55] WILLIS, C. H. and HERSKIND, C. C. Rectifier Terminology and Circuit Analysis, AIEE Transactions, vol61, July 1942, pp 496498.

Phase AC Thyristor Voltage Regulator, IEE Conference Pub no 1 1 0, April 1974, pp 198202. [B67] DEWAN, S. B. Harmonic Analysis of AC-to-AC Frequency Converters, IEEE Trunsactions, vol IGA-5, Jan/Feb 1969, pp 29-33. [B68] DEWAN, S. B. and KANKAM, M. D. A Method for Harmonic Analysis of Cycloconverters. IEEE Transactions, vol IGA-6, Sept/ Oct 1970, pp 455-462. 9.5.2 Effects of Unbalance and Source Impedance [B69] STAHL, B. P. Interaction Between SCR Drives, IEEE Trunsactions, vol IGA-4, Nov/Dec 1968, pp 596-599.

[ B56] HERSKIND, C. C. Rectifier-Circuit Duty, AIEE Transactions, vol 63, March 1944, pp 123-128.

[B57] GALLOWAY, J. H. Harmonic Line Currents in Large Thyristor Six-Pulse Converters, IEEE Industry Application Society 8 t h Annual Meeting Record, Oct 1973, p p 753-759. [B58] DUFF, D. L. and LUDBROOK, A. Semiconverter Rectifiers Go High Power. IEEE Transactions, vol IGA-4, Mar/Apr 1968, pp 185-192.

[B70] FRERIS, L. L. Effects of Interaction Among Groups in a Multigroup AC/DC Converter, IEE Proceedings, vol 114, July 1967, pp 965-973.

[B59] McMURRAY, W. A Study of Asymmetrical Gating for Phase-Controlled Converters, IEEE Transactions, vol IA-8, May/June 1972, pp 289-295.

[B71] PALMER, L. W. Design and Specification t o Minimize the Harmonic Current Generation Effect of Thyristor Drives, IEE Conference Pub no 93, Oct 1972, pp 162-167.

[B60] MEHTA, P. and MUKHOPADHYAY, S. Improvement in DC Motor Performance by Asymmetrical Triggering: Part I - One Quadrant Drive. IEEE Industry Application Society 8th Annual Meeting Record, Oct 1973, pp 615-633.

[B72] SHERMAN, W. G. Summation of Harmonics with Random Phase Angles, Proceedings IEE, V O 119, ~ NOV1972, pp 1643-1648. [B73] ROWE, N. B. The Summations of Randomly-Varying Phasors or Vectors with Particular Reference t o Harmonic Levels, IEE Conference Publication no 110, April 1974, pp 177-181.

[B61] PERRIN, E. M. and SCHONHOLZER, E. T. Fundamental Operation of Rectifiers with Thyristor AC Power Control, IEEE Transactions, vol IA-9, July/Aug 1973, pp 453-461.

[B74] BLYE, P. W. and KENT, H. E. Effects of Rectifiers on System Wave Shapes, AIEE Transactions, vol 53, Jan 1934, pp 54-63.

[B62] SCHMUCK, K. Reaction Effects on the Supply System Caused by Hexapulse Static Converters with Sequential Control, Brown Boveri Review, Nov 1971, pp 514-520.

[B75] EVANS, R. D. Harmonics and Load Balance of Multiphase Rectifiers, Transactions AIEE, V O ~62,1943, pp 182-187.

[B63] ZANDER, H. Self-Commutated Rectifier t o Improve Line Conditions, Proceedings IEE, vol120, Sept 1973, pp 977-981.

[B76] ORKINA, B. G. Higher Harmonics in a Power System Supplying Mercury Rectifiers, Direct Current, vol2, June 1955, pp 115-121.

[B64] BURKART, R. M. and BURTNESS, R.

W. Lamp Acoustical Noise and the Reverse

[B77] Propagation of Harmonic Currents and Voltages Through a Transmission System : CEGB Tests, Direct Current, vol 9, Nov 1964, pp 156,161.

Phase Controlled Dimmer, IEEE Transactions, vol IA-8, Jan/Feb 1972, pp 84-88.

I

[B65] LLOYD, S. A Thyristor AC Regulator with Sinusoidal Output, IEE Conference Publication N o 53, May 1969, pp 168-176.

[B78] PHADKE, A. G. and HARLOW, J. H. Generation of Abnormal Harmonics in HighVoltage AC-DC Power Systems, IEEE Trans-

[B66] MARSHALL, P. and LLOYD, S. A 345

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

actions, vol PAS-87, Mar 1968, pp 873-882.

[B90] REEVE, 6. and BARON, J. A. Harmonic DC Line Voltages Arising from HVDC Power Conversion, IEEE Transactions, vol PAS-89, Sept/Oct 1970, pp 1619-1624.

[B79] REEVE, J. and KRISHNAYYA, P. C. S. Unusual Current Harmonics Arising from HighVoltage DC Transmission, IEEE Transactions, V O PAS-87, ~ Mar 1968, pp 883-893.

[B91] CZUBKOWSKI, R. Application of Thyristor Converters to Electric Mining Shovels, 1 977 IEEE/IAS International Semiconductor Power Converter Conference, IEEE 77CH118331A, pp 371-382.

[B80] REEVE, J. A General Approach t o Harmonic Current Generation by HVDC Converters, IEEE Transactions, vol PAS-88, July 1969, pp 989-995.

9.5.3 Passive Harmonic Filters and Power Factor Correction [B92] FEASTER, W. C. and HARDER, E. L. System Lower-Harmonic Voltages - Methods of Calculation and Control by Capacitors, AIEE Transactions, vol 60, 1941, pp 10601066.

[B81] REEVE, J. and BARON, J. A. Harmonic Interaction Between HVDC Converters and AC Power Systems, IEEE Transactions, vol PAS-90, NOV1971, pp 2785-2793. [B82] REEVE, J. and RAO, T. S. Dynamic Analysis of Harmonic Interaction Between AC and DC Power Systems, IEEE Transactions, vol PAS-93, Mar/Apr 1974, pp 640-646.

[ B93] STACKEGARD, H. Capacitor Bank with Harmonic Filters, ASEA Journal, vol 34, no 5,1961, pp 75-78.

[B83] HINGORANI, N. G. and BURBERY, M. F. Simulation of AC System Impedance in HVDC System Studies, IEEE Transactions, vol PAS-89, May/June 1970, pp 820-828.

[B94] PHADKE, A. G. and HARLOW, J. H. Generation of Abnormal Harmonics in HighVoltage AC-DC Power Systems, IEEE Transactions, PAS-87, March 1968, pp 873-882.

[B84] LIPS, H. P. Aspects of Multiple Infeed of HVDC Inverter Stations into a Common AC System, IEEE Transactions, vol PAS-92, Mar/Apr 1973, pp 775-779.

[B95] DEWAN, S. B. Input Filter Design with Static Power Converters, IEEE Transactions, V O IGA-6, ~ July/Aug 1970, pp 378-383.

[k85] NORTHCOTE-GREEN, J. E. D. The Computation of Impedance-Frequency Loci and Harmonic Current Penetration for AC Systems Adjacent to HVDC Conversion Equipment, IEE Conference Pub no 107, Nov 1973, pp 97-102.

[B96] GILSIG, T. An Interconnected AC Filter for High Voltage DC Converters, IEEE Transactions, vol PAS-89, Mar 1970, pp 463469. [B97] BARON, J. A. Combined PrimaryTertiary AC Filters for HVDC Applications, IEE Conference Pub no 107, 1973, pp 1-5.

[B86] KITCHIN, R. H. and HAY, J. L. Digital Simulation of Waveform Distortion Due t o Converters, IEEE Conference Pub no 110, April 1974, pp 193-197.

[B98] BREWER, G. L. A Simple Method for Estimating Harmonic Filter Performance, IEE Conference Pub no 110, April 1974, pp 162167.

[B87] CORBYN, D. B. Abnormal Harmonic Disturbances: Assessment and Mitigation, IEE Conference Pub no 110, April 1974, pp 235240. [B88] HOOPER, C. K. and McADIE, C. H. Effects of Supply Line Unbalance on the Filtered Output Ripple of Polyphase Rectifiers, AIEE Transactions, vol 69, pt 11, 1950, pp 766-770.

[B99] BIALKIEWICZ, Z. S. Reducing of Harmonics in MV Networks with LC-Filters, IEE Conference Pub no 1 1 0, 1974, pp 151-155. [BlOO] SHEPHERD, W. and ZAKIKHANI, P. Power Factor Correction in Nonsinusoidal Systems by the Use of Capacitance, Journal o f Physics D : Applied Physics, vol 6, 1973, pp 1850-1861.

[B89] PINTSOY, A. M. The Calculation of the Harmonics of Audio Frequency Currents in DC Power Lines, Direct Current, vol4, June 1958, pp 8-13.

[BlOl] SHEPHERD, W. and ZAKIKHANI, P. Power Factor Compensation of Thyristor-Con46

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

--

trolled Single-phase Load, IEE Proceedings, vol120, Feb 1973, pp 245-246.

tance, IEEE Transactions, vol IECI-20, May 1973, pp 61-68.

[B102] STEEPER, D. E. and STRATFORD, R. P. Reactive Compensation and Harmonic Suppression for Industrial Power Systems Using Thyristor Converters, IEEE Transactions IA-12, May 1976, pp 232-255.

[B113] MATHUR, R. M. and SHARAF, A. M. Harmonics on the DC Side in HVDC Conversion, IEEE Transactions PAS-96, Sept 1977, pp 1631-1638. 9.5.5 Active Compensation and Harmonic Injection [B114] Survey of Arc-Furnace Installations on Power Systems and Resulting Lamp Flicker, AIEE Transactions, vol 76, pt 11, Sept 1957, pp 170-183.

[B103] GYUGYI, L. Reactive Power Generation and Control by Thyristor Circuits, IEEE Power Electronics Specialists Conference, 1976, pp 174-184. [B104] PITEL, I. and TALUKDAR, S. N. A Review of the Effects and Suppression of Power Converter Harmonics, IEEE/IAS Annual Meeting, 1977, pp 119-126.

[B115] CONCORDIA, C. Selection of Buffer Reactors and Synchronous Condensers on Power Systems Supplying Arc-Furnace Loads, AIEE Transactions, vol 76, pt 11, July 1957, pp 123-135.

[B105] SCHIEMAN, R. T. and SCHMIDT, W. C. Power Line Pollution by 3-Phase Thyristor Motor Drives, IEEE/IAS Annual Meeting, 1976, pp 680-690.

[B116] KENDALL, P. G. Light Flicker in Relation to Power-System Voltage Fluctuation, IEEE Proceedings, ~ 0 1 1 1 3 , 1 9 6 6pp , 471-479.

[B106] GALLOWAY, J. H. Line Current Waveforms and Harmonics for a Large MultiPhase Converter System, IEEE Transactions IA-13, Sept 1977, pp 394-399.

[B117] MULCAHY, J. A. and LUDBROOK, A. A New Flicker Correcting System for Arc Furnaces, Journal o f Metals, April 1967, pp 63-66.

[B107] MELVOLD, D. J. Pacific HVDC Intertie System AC Side Harmonic Studies, IEEE Transactions PAS-92, March 1973, pp 690701. 9.5.4 DC Filters and Critical Inductance [B108] MICOSKY, W. J. and HOVIS, G. R. Filter Design for SCR Type DC Power Converters, IEEE Industrial and General Applications 6th Annual Meeting Record, Oct 1971, pp 347-360.

[B118] FRANK, H. and LANDSTROM, B. Power-Factor Correction with Thyristor-Controlled Capacitors, ASEA Journal, ~0144,1971, pp 180-184. [ B1191 Thyristor-Switched Capacitors Curb Furnace Flicker, Electrical Review, Aug 9, 1974, pp 164-166.

[B120] OLTROGGE, A. R. Fundamental Criteria for Large Arc Furnace Power Systems, Journal of Metals, Jan 1971, pp 53-64.

[B109] OVERBECK, W. P. Critical Inductance and Control Rectifiers, IRE Proceedings, vol 27, Oct 1939, pp 655-659.

[B121] JOHNSON, E. R. Static High Speed VAR Control for Arc Furnace Flicker Reduction, Proceedings of the American Power Conference, ~ 0 1 3 4 , 1 9 7 2pp , 1097-1105.

[BllO] DISTLER, R. J. and MUNSHI, S. G. Critical Inductance and Controlled Rectifiers, IEEE Transactions, vol IECI-12, March 1965, pp 34-37.

[B122] FRANK, H. and IVNER, S. Power Factor Correction Equipment for Arc Furnaces Using Thyristor-Controlled Capacitors, Iron and Steel International, Feb 1974, pp 33-38.

[ B l l l ] DISTLER, R. J. and DUNNE, D. J. An Improvement of the Critical Inductance Criterion, IEEE Transactions, vol IECI-12, Nov 1965, pp 44-46.

--.

[B123] CRONIN, J. New Concepts for VAR Supply, Transmission and Distribution, Feb 1974, pp 60-64.

[B112] SCHWARTZ, F. C. A Time-Domain Analysis of the Power Factor for a Rectifier Filter System with Over-and Subcritical Induc-

[B124] KILGORE, L. A. and WASHBURN, D. C. Energy Storage at Site Permits Use of 47

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

Large Excavators on Small Power Systems, Westinghouse Engineer, vol 30, Nov 1970, pp 162-167.

[B136] AMEMIYA, Y. and SOWA, M. Harmonic Reduction in a Bridged Rectifier Circuit by Means of an AC Branch Across the Load, Electrical Engineer of Japan, vol 93, Feb 1973, pp 54-59.

[B125] FINLAYSON, P. T. and WASHBURN, D. C. Cycloconverter-Controlled Synchronous Machines for Load Compensation on AC Power Systems, IEEE Transactions, vol IA-10, Nov/ Dec 1974, pp 806-813.

[B137] SASAKI, H. and MACHIDA, T. A New Method t o Eliminate AC Harmonic Currents by Magnetic Flux Compensation-Considerations on Basic Design, IEEE Transactions, vol PAS90, Sept/Oct 1971, pp 2009-2019.

[B126] SINGER, Z. Power Regulation by Means of a Switched Capacitor, IEE Proceedings, v o l l l 9 , Feb 1972, pp 149-152.

[B138] SASKI, H. and MACHIDA, T. Transient Analysis of Harmonic Current Elimination Method by Magnetic Flux Compensation, IEEE Transactions, vol PAS-93, Mar/Apr 1974, pp 669-675.

[B127] SINGER, Z. and ERLICKI, M. S. Analysis of Systems Switched with Alternating Polarity, IEE Proceedings, vol 121, Feb 1974, pp 88-90.

9.6 Effects on Components and Systems [B139] WARDER, S. B. The Influence of Rectifier Harmonics in a Railway System on the Dielectric Stability of 33 kV Cables, IEE Proceedings, vol98, pt 11,1951, pp 399-421. 9.6.1 Transformers and Inductors [B140] DE BLIEUX, E. V. Losses in Transformers for use with Mercury Arc Rectifiers, AIEE Transactions, ~0150,1931,pp 999-1007.

[B128] SINGER, Z. and ERLICKI, M. S. Use of Practical Circuits Switched with Alternating Polarity, IEE Proceedings, vol121, April 1974, pp 249-251. [B129] MIDGLEY, D. and SIGGER, M. Switched Capacitors in Power Control, IEE Proceedings, vol 121, July 1974, pp 703-704. [B130] EMANUEL, A. E. Using Inverters for DC Motor Control, IEEE Industry Applications Society 8 t h Annual Meeting Record, Oct 1973, pp 585-593.

[B141] DE BLIEUX, E. V. Characteristics, Design and Applications of Rectifier Transformers, General Electric Review, vol 40, Sept 1937, pp 412-417; Oct 1937, pp 481-489; Nov 1937, pp 539-542; Dec 1937, pp 590593.

[B131] THORBORG, K. A Three-phase Inverter with Reactive Power Control, IEEE Transactions, vol IA-9, July/Aug 1973, pp 473-481.

[B142] MARTIN, P. N. Transient Conditions in a Transformer Supplying Energy t o a HalfWave Rectifier Circuit, AIEE Transactions, V O ~70, pt 11,1951, pp 1468-1479.

[B132] KANNGIESSER, K. W. and LIPS, H. P. Control Methods for Improving the Reactive Power Characteristic of HVDC Links, IEEE Transactions, vol PAS-89, July/Aug 1970, pp 1120-1125.

[B143] HOLCOMB, J. E. Steady-State Conditions in a Transformer Supplying Energy t o a Half-Wave Rectifier, IEEE Transaction, vol PAS-82,1963, pp 334-352.

[B133] BLAKE, L. R. The Double 3-Phase Rectifier with Inter-Phase Reactor Excited from a Frequency Tripler, IEE Proceedings, V O ~100, pt 11,1953, pp 310-314.

[B144] CREPAZ, S. For an Improved Evaluation of Conventional Losses of Transformers for Converters, IEEE International Semiconductor Power Converter Conference Record, May 1972, pp 2-5-1 t o 9.

[B134] BIRD, B. M. Harmonic Reduction in Multiplex Convertors by Triple-Frequency Current Injection, IEE Proceedings, vol 116, Oct 1969, pp 1730-1734.

[B145] SPECHT, T. R. Transformer Inrush and Rectifier Transient Currents, IEEE Transactions, vol PAS-88, Apr 1969, pp 269-276.

[B135] AMETANI, A. Generalized Method of Harmonic Reduction in AC/DC Convertors by Harmonic Current Injection, IEE Proceedings, V O ~119, July 1972, pp 857-864.

[B146] NAKRA, H. L. and BARTON, T. H. Three-phase Transformer Transients, IEEE 48

IEEE COMPENSATION OF STATIC POWER CONVERTERS

Std 519-1981

Transactions, vol PAS-93, Nov/Dec 1974, pp 1810-1819.

9.6.3 DCMachines [B158] SCHMIDT, A. and SMITH, W. P. Operation of Large DC Motors from Controlled Rectifiers, AIEE Transactions, vol 67, pt I, 1948, pp 679-683.

[B147] WOODBURY, J. R. Design of Imperfectly Coupled Power Transformers for DC to DC Conversion, IEEE Transactions, vol IECI21, Aug 1974, pp 152-159. [B148] NISHIZAKI, T. T. Computer-Aided Design and Weight Estimation of High-Power High-Voltage Power Conditioners, IEEE Transactions, vol AES-7, Nov 1971, pp 1179-1194.

[B159] REITER, C. R. and AMMERMAN, C. R. Increased Losses in a DC Motor When Operated From Grid Controlled Rectifiers, AIEE Transactions, vol 71, pt 11,1952, pp 7782.

[B149] ACOSTA, 0. N. Interphase Transformer for Multiple Connected Power Rectifiers, IEEE Transactions, vol IGA-1, Nov/Dec 1965, pp 423-428.

[B160] DUNAISKI, R. M. The Effect of Rectifier Power Supply on Large DC Motors, AIEE Transactions, vol 79, pt 111, 1960, pp 253-259.

[B150] USHER, T. Design Relationships for Iron-Core Filter Chokes, AIEE Transactions, vol76, pt I, Sept 1957, pp 484-487.

[B161] ROBINSON, C. E. Redesign of DC Motors for Applications with Thyristor Power Supplies, IEEE Transactions, vol IGA-4, Septl Oct 1968, pp 508-514.

[B1511 SUBBARAo, T' and REEVE, Harmonics Caused by Imbalance Transformer Impedances and Imperfect Twelve-Pulse Operation in HVDC Conversion, IEEE Transactions, PAS-95, Sept 1976, pp 1732-1737.

[I31621 DEMERDASH, N. A. 0. and HAMILTON, H. B. Effect of Complex Forms on Copper Losses in Large DC Motors, IEEE 5th Industrial Applications Society Annual Meeting Record, Oct 1970, pp 77-81 (Reprinted in Power Semiconductor Applications, vol I, IEEE Press, 1972, pp 427-431.

J'

9.6.2 Capacitors [B152] SCHMIDT, A. Capacitors in Power Systems with Rectifier Loads, AIEE Transactions, vol72, pt I, 1953, pp 14-17.

[B163] FRANKLIN, P. W. Theory of the DC Motor Controlled by Power Pulses: Part I Motor Operation: P& I1 - Braking Methods, Commutation, and Additional Losses, IEEE Transactions, vol PAS-91,1972, pp 249-262.

[B153] SCHMIDT, A. Capacitors in Power Systems with Rectifier Loads, Direct Current, V O ~ 4, March 1959, pp 116-119. [B154] Paper, Paper/Film, Film Dielectric Capacitors for Power Semiconductor Applications EIA Standard RS-401, March 1973, (ANSI C83.97-1973).

[B164] JONES, D. Ripple Current Effects on DC Servo Motors, Machine Design, Sept 1971, pp 63-66. [B165] GYUGYI, L. and STRYCULA, E. C. Active AC Power Filters, IEEE/IAS Annual Meeting, 1976, pp 529-535. 9.6.4 AC Machines [B166] JAIN, G. C. The Effect of Wave-Shape on the Performance of a 3-Phase Induction Motor, IEEE Transactions, vol PAS-83, June 1964, pp 561-566.

[B155] ROBINSON, W. M. EIA Standards for Commutating Capacitors, IEEE International Semiconductor Power Converter Conference Record (IEEE Catalog no 72-CHO-602-3-IA), May 1972, pp 1-9-1to 11. [B156] HIRE, L. L. Thermal Considerations of AC Resonating Capacitors in Ferroresonant Applications, IEEE Industry Application Socie t y 9th Annual Meeting Record, Oct 1974, pp 293-298.

[B167] KLINGSHIRN, E. A. and JORDAN, H. E. Polyphase Induction Motor Performance and Losses on Nonsinusoidal Voltage Sources, IEEE Transactions, vol PAS-87, Mar 1968, pp 624-631.

[B157] MOORE, A. H. Application of Power Capacitors to Electrochemical Rectifier. IEEEIAS Transactions, vol 1A-13, no 5, Sept/Oct 1977, pp 399-406.

[B168] CHALMERS, B. J. and SARKER, B. R. Induction Motor Losses Due to Nonsinusoidal 49

IEEE Std 519-1981

IEEE GUIDE FOR HARMONIC CONTROL AND REACTIVE

Supply Waveforms, IEE Proceedings, vol 115, Dec 1968, pp 1777-1782.

Power Systems With Rectifier Load, AIEE Transactions, vol 63,1944, pp 91-96.

[B169] McLEAN, G. W. Performance and Design of Induction Motors with Square-Wave Excitation, IEE Proceedings, vol 116, pp 14051411.

[B180] AIKENS, A. J. and LEWINSKI, D. A. Evaluation of Message Circuit Noise, Bell Telephone System Monograph 3661, vol 39,1960, pp 1-31.

[B170] LARGIADER, H. Design Aspects of Induction Motors for Traction Applications with Supply Through Static Frequency Changers, Brown-Boveri Review, vol 57, April 1970, pp 152-167.

[B181] COCHRAN, W. T. and LEWINSKI, D. A. A New Measuring Set for Message Circuit Noise, Bell Telephone System Monograph 3661, V O ~ 39,1960, pp 33-53. [B182] BOZZELLA, S. J. Harmonics from Railroad Rectifiers on Power Systems Reduced by Filters, AIEE Transactions, vol 74, pt 11, NOV1955, pp 324-335.

[B171] LIPO, T. A. Harmonic Torque and Speed Pulsations in a Rectifier-Inverter Induction Motor Drive, IEEE Transactions, vol PAS88, May/June 1969, pp 579-587.

[B183] BALL, W. C. and POARCH, C. K. Telephone Influence Factor (TIF) and its Measurement, AIEE Transactions, vol 79, pt 11, Jan 1961,659-664.

[B172] ROBERTSON, S. D. T. and HEBBAR, K. M. Torque Pulsations in Induction Motors with Inverter Drives, IEEE Transactions, vol IGA-7, Mar/Apr 1971, pp 318-323.

[B184] MEYER, W. S. and DOMME, H. W. Telephone-Interference Calculation for Multiconductor Power Lines, IEEE Transactions, V O PAS-88, ~ Jan 1969, pp 35-41.

[B173] KLIMAN, G. B. Harmonic Effects in Pulse Width Modulated Inverter Induction Motor Drives, IEEE 7 t h Industry Applications Society Annual Meeting Record, Oct 1972, pp 783-790.

[B185] DEFTY, J. W. and MAPLES, G. C. Harmonic-Measurement Facility for PowerSupply Systems, IEE Proceedings, vol 117, 1970, pp 1993-1996.

[B174] JACOVIDES, L. J. Analysis of Induction Motor Drives with a Nonsinusoidal Supply Voltage Using Fourier Analysis, IEEE Transactions, vol IA-9, Nov/Dec 1973, pp 741-747.

[B186] BUCKEL, R. Signaling and Communications Problems Arising from Thyristor Control in Electric Traction, IEEE International Semiconductor Power Converter Conference Record (IEEE Catalog no 72 CHO 602-3-IA), May 1972, pp 3-13-1t o 19.

[B175] BECK, C. D. and CHANDLER, E. F. Motor Drive Inverter Ratings, IEEE Transactions, vol IGA-4, Nov/Dec 1968, pp 589-595. 9.6.5 Telephone and Communications EM1 [B176] Engineering Reports of the Joint Subcommittee on Development and Research of the Edison Electric Institute and the Bell Telephone System, 5 Volumes, July 1926 t o January 1943.

[B187] MORI, H. Harmonic Analysis of Chopper Controlled Electric Rolling Stock, IEEE Transactions, vol IA-9, May/June 1973, pp 302-309.

[B177] BARSTOW, J. M. Measurement of Telephone Noise and Power Wave Shape, AIEE Transactions, vol 54, Dec 1935, pp 1307-

[B188] ZASTROW, 0. W. Recommended Practice for Voice-Frequency Electrical Noise Tests of Distribution Transformers, IEEE Transactions, COM-21, Dec 1973, pp 14481455.

1315. [B178] PLUCKNETT, K. J. Inductive Coordination of REA Distribution Systems and Telephone Systems, AIEE Transactions, vol 60, 1941, pp 586-595.

[B189] McLELLAN, D. W. and POTTER, D. H. Telephone Interference from Power Line Loads Regulated by Semiconductor Control Devices, IEEE/IAS Annual Meeting, 1975, pp 1001-1004.

[B179] FRICK, C. W. A Short-cut Method of Estimating Telephone Influence Factor of

50

IEEE Std 519-1981

COMPENSATION OF STATIC POWER CONVERTERS

Cell Power Generation, IEEE Transactions, vol PAS-95. no 3., Mav/June 1976. DD 944-953. ".

[B190] SARMA, M. P. and GILSIG, T. A Method of Calculating the RI From HVDC Converter Stations, IEEE Transactions, vol PAS-92, May/June 1973, pp 1009-1018.

,

A

A

[B192] MICHAELS, L. H., FAIRCHILD, B. T. and KO", S . T. Hybrid Simulation of Fuel Cell Conversion Systems, IEEE Transactions, vol PAS-96, no 4, July/Aug 1977, pp 13291336.

9.6.6 Forced Commutated Converters [B191] PHILLIPS, G. A., VOGT, J. H, and WALTON, J. W. Inverters for Commercial Fuel

51