Major Project Final1.docx

THREE PHASE FULLY CONTROLLED RECTIFIER MAJOR PROJECT-1 Submitted to Rajiv Gandhi Proudyogiki Vishwavidyalaya towards Partial Fulfillment of the Degree of

BACHELOR OF ENGINEERING (Electrical & Electronics Engineering)

GUIDED BY Ms. PRIYA PAL SUBMITTED BY KRISHNA GOPAL KUNAL AHIRRAO KUSHAL BADOLE MAINAK MALLICK NAYAN UPADHYAY

IPS ACADEMY INSTITUTE OF ENGINEERING & SCIENCE, INDORE ELECTRICAL & ELECTRONICS ENGINEERING DEPARTMENT 2018-19

A C K N OW L E D G E M E N T It is our great pleasure to express our profound gratitude to our esteemed guide Ms. Priya Pal Professor, Electrical and Electronics Engineering Department, IES, IPS Academy Indore for his valuable inspiration, able guidance and untiring help, which enabled us to carry out and complete this work. We are grateful to Mr. Manish Sahajwani, Professor & Head-Department of Electrical and Electronics Engineering IES, IPS Academy Indore, for his keenness towards this work and efforts put in, and also for sharing his valuable time to our problems and providing useful solutions We express our sincere gratitude to Dr. Archana Keerti Chowdhary, Principal, IES, IPS Academy, Indore for extending all the facilities during the course of study. At this juncture we also take this opportunity to express our deep gratitude to all the faculty and staff of Electrical and Electronics Engineering Department, for their appreciation and moral support. We are also thankful to all our friends who helped us directly or indirectly to bring the dissertation work to the present shape.

Date:

Name of Student KRISHNA GOPAL KUNAL AHIRRAO KUSHAL BADOLE MAINAK MALLICK NAYAN UPADHYAY

IPS ACADEMY INSTITUTE OF ENGINEERING & SCIENCE, INDORE ELECTRICAL & ELECTRONICS ENGINEERING DEPARTMENT

RECOMMENDATION It is recommended that the Major Project-1 (Planning and Literature survey) EX-7006 entitled “THREE PHASE FULLY CONTROLLED RECTIFIER” submitted by following students may be accepted. KRISHNA GOPAL SINGH KUNAL AHIRRAO KUSHAL BADOLE MAINAK MALLICK NAYAN UPADHYAY

Roll No. 0808EX151031 Roll No. 0808EX151033 Roll No. 0808EX151034 Roll No. 0808EX151036 Roll No. 0808EX151041

Guide By

HOD

Ms. Priya Pal

Prof. Manish Sahajwani

IPS ACADEMY INSTITUTE OF ENGINEERING & SCIENCE, INDORE ELECTRICAL & ELECTRONICS ENGINEERING DEPARTMENT

CERTIFICATE We are pleased to certify that the Major Project-1 (Planning and Literature survey) EX-7006 entitled “THREE PHASE FULLY CONTROLLED RECTIFIER” submitted by following students is accepted. KRISHNA GOPAL SINGH KUNAL AHIRRAO KUSHAL BADOLE MAINAK MALLICK NAYAN UPADHYAY

INTERNAL EXAMINER Date:

Roll No. 0808EX151031 Roll No. 0808EX151033 Roll No. 0808EX151034 Roll No. 0808EX151036 Roll No. 0808EX151041

EXTERNAL EXAMINER Date:

ABSTRACT Three phase AC to DC conversion of electric power is widely employed in adjustable speed drives (ASDs), uninterruptible power supply (UPSs), HVDC systems and utility interfaces with non-conventional energy sources such as electroplating welding units etc, battery charging for electric vehicles and power supplies for telecommunication systems. The purpose of this project is to successfully convert three phase ac to dc conversion of electric power using SCRs. AC to DC line commutated converters are used as the most usual choice for application. This is due to simplicity of the circuits requiring a minimum number of active and passive components. Thyristors or SCRs are the main line commutated power switches. This project is built on thyristors and a control or firing system using ATmega328p microcontroller which is used to trigger the three phase full-controlled bridge rectifier. it adopts three synchronization signals, 6-channels trigger pulses from it are very symmetrical and the pulses can be shifted within a cycle of a sine wave from 0 degree to 162 degrees. Structure of this circuit is simple and consists of the rectifier circuit consisting of the 6-SCRs and the isolation circuit with the protection system, a microcontroller a LCD screen ,synchronization circuits and the control voltage circuit. Its performance is high stable and reliable. Its anti-interference ability is strong and its operation is easy. A zero crossing circuit attached to the AC lines produces a digital signal to the processor (based on signal zero crossings) that is captured and used to predict the next zero crossing capture time and fire the SCR’s based on this prediction. For accuracy and precision, a phase locked loop algorithm is implemented in software that works to improve the accuracy of the next predicted zero crossing and locks to produce the desired output voltage.

Table of Contents CH NO

TOPIC NAME

1.

INTRODUCTION

1.1. 1.2. 1.3. 1.4. 1.5. 1.6.

Overview Background Objectives Scope Problem Statement Project Report

2.

LITERATURE REVIEW

2.1.

Introduction

2.2. 2.2.1. 2.2.2.

Theory of Rectifires Single Phase Rectifiers Three Phase Rectifiers

2.3.

Thyristor Commutation Effect of the AC Input Reactance

2.4.

Power Displacement Factor and Power Factor

2.5.

Effects on the AC Main Voltage

2.6. 2.6.1. 2.6.2. 2.6.3.

How to Reduce the Harmonic on the AC Main Three Phase Line Reactor DC Line Choke Passive Filters

2.7. 2.7.1. 2.7.2. 2.7.3. 2.7.4. 2.7.5.

Silicon Controller Rectifiers Working of SCR Switching Characteristics of SCR SCR Rating Gate Circuit Requirement SCR Protection

2.8.

Previous Researches

3.

Methodology

3.1

Introduction

3.2. 3.2.1. 3.2.2. 3.2.3. 3.2.4. 3.2.5.

Design Input The Rectifiers Circuit Sychronization of circuit / Zero Crossing Detector Controlling voltage Generating of the firing pulses

3.3. 3.3.1. 3.3.2.

Software Design Main Program ADC program for delay

4.

Refferences

Page No 1

4

18

24

TABLE OF FIGURES S.No

Name of Figure

Page No.

1 2 3 4

Rectifier inverter Chopper Power electronics interface between the power processor and controller Uncontrolled rectifier and sub divisions controlled rectifier and sub divisions Single-phase half wave diode rectifier-R/L Load A basic half wave controlled rectifier a. The Bridge Rectifier b. Single diode rectifier waveforms c. The centre-tapped Transformer rectifier A full wave controlled bridge rectifier Single way rectifier a. Source and output voltage

1 1 1 2

5 6 7 8 9

10 11 12 13 14

15 16

17 18 19 20 21

Three-phase bridge rectifier (a) & (b) it’s ideal equivalent circuit

a. Fully-controlled three phase bridge ciruit, b. The output voltage waveforms with small fring angle and c. with large firing angle Commutation of thyristor from one phase to another two- transistor model of the thyristor (SCR) (a and b) and its symbol Layer diagram of thyristor The static V-I characteristic of an SCR a. firing network load line Three phase controlled rectifier circuits Tri-phase control rectifier block diagram

5 6 6 7

Figure 10 b: single diode rectifier waveform 7

8 8 9 9 11

11 15

15 16 17 18 18

22

The input circuit to rectifier

19

23

Three phase connected to the supply with the snubber circuits and isolation circuit MOC3021 isolator connection to SCR and interface with ATmega328p microcontroller zero crossing circuit with input transformer square wave zero crossing signals of the two phases Controlling Voltage circuit waveform of the output pulse flow chart ADC subroutine and delay control

19

24

25 26 27 28 29

20

20 21 21 22 23