M3

Power Quality Training Courses

Voltage fluctuations/flicker

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LPQIVES is a programme of:

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Module 3 Voltage fluctuations/flicker

1 INTRODUCTION Voltage fluctuations are the specific type of electromagnetic disturbances as their main effect – the phenomenon of light flicker – appears in the form of a negative direct influence on the human organism. Light flicker is the subjective sensation of variations in the luminous flux, whose luminance or spectral distribution fluctuates with time. Moreover, voltage fluctuations are the reason of adverse effects of technical and economic nature.

1.1 General aims The seminar describes the flicker phenomenon and discusses the sources of voltage fluctuations and their effects. It presents methods for analysis, measurement and limitation of voltage fluctuations in electric power networks. It describes the current state of standardization of the phenomenon in the light of international and national rules, and particularly considers the problems that are important for contracts closed between energy suppliers and consumers.

1.2 Target groups This module’s target group are mainly: − end-users of equipment − designers − installers or contractor of installations − electric networks operators − equipment sellers and services providers in the electricity sector.

2 SPECIFIC AIMS AND TOPICS The pathway of learning consists of a 2 days course, subdivided in sections (with different duration), with these contents and related aims.

Contents

Aims

Contents

Aims

1st day Introduction, Basic terms and definitions, Description of the disturbances, Sources of voltage fluctuations Effects of voltage fluctuations Measuring methods and instrumentation Supplying knowledge concerning theoretical basics of disturbances, its sources, effects, and methods of assessment by means of measuring 2nd day Standardisation of voltage fluctuations, flickermeter – emission and immunity tests, customer connection requirements (responsibility of the supplier, and the customer), measurement and assessment of voltage fluctuations Supplying knowledge concerning principles of measuring, contract formulation. Use of the obtained knowledge to analysis and solving problems related to voltage fluctuation (ASD, wind generation), and to practical measurements in laboratory.

Below there’s a detailed overview of the course contents.

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2.1

Pathway of learning flow chart

Time progression (hours)

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COURSE DETAILED PROGRAM

First day: 60 mins

Participants registration - Akademia Górniczo-Hutnicza, Kraków Pawilon B1, sala 25

5 mins

Openning, informations, course introduction, course introduction

55 mins

Section 1: Introduction − Basic terms and definitions − Description of the disturbances − Sources of voltage fluctuations (arc furnaces, induction motors etc.) − Effects of voltage fluctuations (influence on human organism, light sources, other equipment) Modality: Lesson and discussion

60 mins

Mitigation of voltage fluctuations (general compensator, static compensators - SVC) Modality: Lesson and discussion

15 mins

Coffee break

60 mins

Section 2: Measuring methods and instrumentation (flickermeter, measured flicker severity) Modality: Lesson, computer laboratory and discussion

considerations,

synchronous

Second day: 45 mins

Section 3: Standardisation of voltage fluctuations (general considerations, compatibility levels, emission of voltage fluctuation, immunity levels, connection of disturbing customers in MV and HV systems, voltage fluctuations in national regulations Modality: Lesson and discussion

45 mins

Static compensators Modality: Laboratory and discussion

15 mins

Coffee break

60 mins

Section 4: Flickermeter – emission and immunity tests Modality: Laboratory and discussion

60 mins

Customer connection requirements (responsibility of the supplier and customer) − Case study 1 - ASD − Case study 2 - wind generation Modality: Lesson and discussion

15 mins

Coffee break

60 mins

Section 5: Measurement and assessment of voltage fluctuations Modality: Laboratory and discussion

30 mins

Final discussion and conclusions, End of the course, user satisfaction survey (user’s questionnaire),

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the

Confirmations of attendance

4 − − − −

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GENERAL NOTES each day there will be two coffee breaks according to the seminar program; at the beginning of the course the lecturer will explain course aims and at the end he will verify their fulfilment; the course will be divided in theoretical and practical sections; at the end of the lessons, a user satisfaction survey will help the lecturer in monitoring the course quality.

TEACHING METHODS

Teaching methods are summarized in three main moments: − − −

knowledge transfer (Lesson) topics exposure by the lecturer with the help of slides and presentation of practical cases; deepening/learning verification (Discussion) general discussion stimulated by the lecturer (also during the lesson) to verify knowledge transfer; practical training, laboratory activities; group work

During all the sections, the lecturer will always attend, with teaching and/or activity coordination duty.

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DIDACTIC MATERIAL

The didactic tools which will be used by the lecturers will be: − Blackboard − Video-projector − Notebook − Microphone The lecture room will be suitable to allow the use of all the above listed didactic tools and to enable group work for the attendants. Each user will receive, during the registration, a folder containing: − course program; − lecture notes containing all or part of the lecture slides; − LPQIVES knowledge database access personal key. All this didactic material, and eventually some additional electronic tools, will be available also in electronic format at: http://lpqi.org/custom/1036/. The folder will also include a user satisfaction questionnaire and a knowledge test (which will be both filled and submitted at the end of the course). 7

EXISTING KNOWLEDGE REQUIREMENTS

The following (on the basic level) shall be prerequisite for the participant: www.lpqi.org

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− electric circuits theory: AC circuits − electric machines − electric power engineering; power system − power electronics electric metrology.

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ACQUIRED COURSE KNOWLEDGE

The knowledge acquired during the course should be sufficient for: − identification of the distortion nature − distortion source identification − disturbance assessment by means of measuring − evaluation of technical and economic effects of disturbance − proposing remedial measures formulation of contract between the supplier and consumer of electric power on the basis of the existing standards and regulations. 9

ANNEXES - MIDAS REPORT

Press 1. PR-00011, McGranaghan, M, Economic evaluation of power quality, IEEE Power Engineering Review, 01/02/2002 Facility managers and utility engineers must evaluate the economic impacts of the power quality variations against the costs of improving performance for the different alternatives.

2. PR-00020, Gurney, J, Hughes, B, Li, C, Neilson, B, Xu, W, Virtual PQ troubleshooter, IEEE power & energy magazine, may/june 2003 The authors describe a prototype instrument that locates the sources of power quality disturbances and is geared toward power system troubleshooting and management.

Publication 3. REP-00002, 2004, 1-9 Power Quality Glossary, Application note The glossary of main technical terms used in PQ

4. REP-00017, 2003, 5-1-4 Voltage fluctuation - flicker, Application Note Extended application guide on flicker. Causes, effects, measurement, mitigation.

5. REP-00018, 2003, 5-2-2 Annex - Monitoring Instruments, Application Note PQ monitoring instruments available on the market - comparison

6. REP-00019, 2003, 5-2-2 Voltage disturbance monitoring, Application Note Application guide about basics of monitoring equipment. Standards

7. REP-00020, 2003, 5-2-3 Flicker measurement, Application Note Extended application note about flicker measurement - principle, calibration.

8. REP-00021, 2002, 5-3-3 Dip resilient variable speed drives, Application Note Application note about different methods of voltage dip mitigation. Subjects: - Effects of voltage dips and short supply interruptions - Methods of voltage dips effects mitigation

9. REP-00023, 2003, 5-3-5 Flicker case study, Application Note Arc furnace produces flicker. How to mitigate?

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10. REP-00024, 2003, 5-3-6 Mitigation of voltage unbalance, Application Note Unbalance standards, limits, symmetrization - examples (calculations) Subjects: - Standardization - Principles of compensation and symmetrization - Static compensators

11. REP-00109, 2003, Voltage fluctuation in electric supply system. Application note no. 7, Application note Voltage fluctuations in the electric supply system - subjects: 1. What are voltage fluctuations? 2. Effects of voltage fluctuations 3. Causes of voltage fluctuations 4. Calculation of the flicker indices 5. Voltage fluctuation standards and planning levels 6. Reducing the effects of voltage fluctuations

12. REP-00125, 2002, Specification guidelines to improve power quality immunity and reduce plant operating costs, Paper There are many useful IEEE and IEC standards that support the design of chemical and petrochemical plants. This article brings relevant Power Quality standards information together and provides recommendations in areas not yet covered in current standards. Circuit configurations for cost saving solutions are provided.

13. REP-00144, 1996, Guide to quality of electrical supply for industrial installations. PART 1: Types of disturbances and relevant standards, Brochure (Document available in the library of Katholieke Universiteit Leuven) 1. Scope 2. Introduction to the concept of electromagnetic compatibility (EMC) 2.1. Definition of EMC 2.2. Basic concepts 2.3. Compatibility, emission and immunity levels 2.4. The concept of electromagnetic environment 3. Types of disturbances, origins and effects 3.1. General classification 3.2. Harmonics 3.3. Interharmonics 3.4. Voltage fluctuations 3.5. Voltage dips and short (supply) interruptions 3.6. Voltage unbalance - asymmetry 3.7. Power frequency variations 3.8. Transient overvoltages 3.9. Mains siganlling 3.10. Reference to HF conducted and LF and HF radiated disturbances 4. Coordination strategies among the involved parties 4.1. Evaluation of the disturbance emission level 4.2. Immunity of equipment 4.3. Mitigation techniques 4.4. Prediction studies for installation requirements 4.5. An approach to measurement criteria 5. Main standards and othter EMC publications 5.1. Recent developments in the approach to evaluating EMC coordination 5.2. Relevant EMC standards on EMC 5.3. CENELEC and national EMC standards and publications 5.4. Relevant publication from other international bodies dealing with EMC 6. Glossary of terms and definitions 7. Abbreviations 8. References Appendix A. Disturbance compatibility levels in figures A-1. Electromagnetic compatibility levels for low-, medium- and high-voltage public distribution networks A-2. Electromagnetic compatibility levels for indoor industrial plants

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14. REP-00146, 2000, Understanding power quality problems - Voltage sags and interruptions: 1. Overview of power quality and power quality standards, Book Chapter 1 of the book "Understanding power quality problems - Voltage sags and interruptions" (IEEE Press, ISBN 0-7803-4713-7) Interest in power quality Power quality, voltage quality Overview of PQ phenomena PQ and EMC standards

15. REP-00149, 2000, Understanding power quality problems - Voltage sags and interruptions: 4, Voltage sags - Characterization, Book Chapter 4 of the book "Understanding power quality problems - Voltage sags and interruptions" (IEEE Press, ISBN 0-7803-4713-7) Voltage sag magnitude Voltage sag duration Three-phase unbalance Phase-angle jumps Magnitude and phase-angle jumps for three-phase unbalanced sags Other characteristics of voltage sags Load influence on voltage sags Sags due to starting of induction motors

16. REP-00150, 2000, Understanding power quality problems - Voltage sags and interruptions: 5. Voltage sags - Equipment behavior, Book Chapter 5 of the book "Understanding power quality problems - Voltage sags and interruptions" (IEEE Press, ISBN 0-7803-4713-7) Computers and consumer electronics Adjustable-speed AC drives Adjustable-speed DC drives Other sensitive loads

17. REP-00151, 2000, Understanding power quality problems - Voltage sags and interruptions: 6. Voltage sags - Stochastic assessment, Book Chapter 6 of the book "Understanding power quality problems - Voltage sags and interruptions" (IEEE Press, ISBN 0-7803-4713-7) Compatibility between equipment and supply Presentation of results: voltage sag coordination chart Power quality monitoring The method of fault positions The method of critical distances

18. REP-00152, 2000, Mitigation of interruptions and voltage sags, Book Chapter 7 of the book "Understanding power quality problems - Voltage sags and interruptions" (IEEE Press, ISBN 0-7803-4713-7) Overview of mitigation methods Power system design - redundancy through switching Power system design - redundancy through parallel operation The system-equipment interface

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