Thesis Title (English)

Student Name

THESIS SUBMITTED IN FULFILMENT OF THE DEGREE OF DOCTOR OF PHILOSOPHY

FACULTY OF ENGINEERING AND BUILT ENVIROMENT UNIVERSITI KEBANGSAAN MALAYSIA BANGI

2011

ii

Thesis Title (Malay)

Student Name

TESIS YANG DIKEMUKAKAN UNTUK MEMPEROLEH IJAZAH DOKTOR FALSAFAH

FAKULTI KEJURUTERAAN DAN ALAM BINA UNIVERSITI KEBANGSAAN MALAYSIA BANGI

2011

iii

DECLARATION

I hereby declare that the work in this thesis is my own except for quotations and summaries which have been duly acknowledged.

Date

Student Name Student Number

iv

ACKNOWLEDGMENTS

First and foremost praise be to Almighty Allah for all his blessings for giving me patience and good health throughout the duration of this PhD research. I am very fortunate to have Professor Dr. … as a research supervisor. Also, I would like to express my high appreciation to my co-supervisor Dr. … Moreover, I am grateful to I would like to thank all post graduate students of UKM power research group for their help, friendship, and creating a pleasant working environment throughout my years in UKM. To my dearest wife Last but not least, I gratefully acknowledge financial support provided by UKM under grant numbers

v

ABSTRACT

The recent changes in utility structures, development in renewable technologies and increased

vi

ABSTRAK

Perubahan terkini dalam struktur utiliti, kemajuan teknologi boleh diperbaharui dan peningkatan

vii

TABLE OF CONTENTS

Page DECLARATION

iii

ACKNOWLEDGMENTS

iv

ABSTRACT

v

ABSTRAK

vi

CONTENTS

vii

LIST OF TABLES

x

LIST OF FIGURES

xii

LIST OF ABBREVIATIONS

xv

LIST OF SYMBOLS

xvi

CHAPTER I

INTRODUCTION

1.1

Research Background

1

1.2

Problem Statement

1

1.3

Objectives of Research and Scope of Works

1

CHAPTER II

LITERATURE REVIEW

2.1

Distributed Generation

2

2.1.1

Distributed Generation

2

2.1.2

Effect of Distributed Generation

2

2.2

2.3 2.4

Protection Issues for Distribution Networks 2.2.1

Short Circuit Currents

3

2.2.2

Power Flow

3

2.2.3

Overcurrent Protection

3

Distribution Systems

3

2.3.1

3

Review of Distribution Networks

Review of Distributed Generation

3

2.4.1

3

Distribution System Protection

viii

2.4.2

Review of Protection Methods

3

2.5

Chapter Summary

4

CHAPTER III

DISTRIBUTION NETWORK

3.1

Introduction

5

3.2

Radial Basis Function Neural Network

5

3.3

Distribution Network

5

3.3.1

Network

5

3.3.2

Classification

5

3.3.3

Location

5

3.3.4

Determination

6

3.3.5

Restoration

6

3.3.6

Generation

6

3.4

Chapter Summary

6

CHAPTER IV

PROTECTION STATEGY

4.1

Introduction

7

4.2

Protection

7

4.2.1

Main and Backup

7

4.2.2

Device

7

4.3

Algorithm

7

4.4

Proposed Strategy

7

4.4.1

Main Algorithm

8

4.4.2

Backup Algorithm

8

4.5

Chapter Summary

CHAPTER V

RESULTS AND DISCUSSION

5.1

Results of

9

5.1.1

14 Bus Test System

9

5.1.2

22 Bus Test System

10

5.1.3

32 Bus Test System

10

5.1.4

Results for Location

11

5.2

8

Results of Strategy

11

5.2.1

11

Results of Strategy for the 14 bus test system

ix

5.2.2

Results of Strategy for the 22 bus test system

11

5.2.3

Results of Strategy for the 32 bus test system

11

5.3

Chapter Summary

CHAPTER VI

CONCLUSION AND FUTURE WORKS

6.1

Conclusion

12

6.2

Significant Contributions of the Research

12

6.3

Suggestions for Future Work

12

REFERENCES APPENDIXES

3

4

x

LIST OF TABLES

Table Number

Page

2.1

Summary of technologies

3

3.1

Fault Type Data

4

4.1

Settings of OC relays

4

4.2

The expected relay in various lines

5

5.1

14-bus test system

6

xi

LIST OF FIGURES

Figure Number

Page

1.1

Electric power system

1

2.1

Short-circuit current

2

2.2

Network equivalent circuit of Figure ‎2.1

3

2.3

Thevenin equivalent circuit

4

xii

LIST OF ABBREVIATIONS

DG: Distributed Generation MLPNN : Multi Layer Perceptron Neural Network RBFNN: Radial Basis Function Neural Network W: Watt kW: kiloWatt MW: Mega Watt AC: Alternating current DC: Direct Current km: Kilometer kV: Kilo Volt MVA: Mega Volte Ampere MSE: Mean Square Error OC: Overcurrent Relay

xiii

LIST OF SYMBOLS

l: Feeder Length d: Distance dtot: Total Feeder Length Z : Impedance Z L : Total Line-Impedance Z DG : The DG Impedance

Z S : The Source Impedance U S : Voltages of the Main Source U DG : Voltages of DG Unit

I : Current I SC : Short Circuit Current I SC , S : The Grid Contribution of the Short Circuit Current

CHAPTER I

1

1.1

INTRODUCTION

RESEARCH BACKGROUND

In the recent years, the electrical utilities are undergoing rapid restructuring process worldwide. In the recent years, the utilities are undergoing rapid restructuring process worldwide. 1.2

PROBLEM STATEMENT

As a high penetration 1.3

OBJECTIVES OF RESEARCH AND SCOPE OF WORKS

This research focuses on the development of new techniques for

CHAPTER II

2

2.1

LITERATURE REVIEW

DISTRIBUTED GENERATION

Typically, distribution systems 2.1.1 Distributed Generation Distributed generation can be defined as the generation of electricity by facilities that are sufficiently smaller than 2.1.2 Effect of Distributed Generation Defining the mesh currents I 1 and I 2 and applying the Kirchhoff’s voltage law for U S and U DG , we get,

 US   ZS  ZL   U DG  (1  l ).Z L

(1  l ).Z L   I1  .  Z DG  (1  l ).Z L   I 2 

(2.2)

where I 1 is the grid contribution of the short circuit current, I SC ,S , and I 2 is the DG-contribution of the short circuit current, I SC , DG , to the total short circuit current. 2.2

PROTECTION DISTRIBUTION NETWORKS IN THE PRESENCE OF DISTRIBUTED GENERATION

Conflicts between DG unit and

3

2.2.1 Short Circuit Currents The fault contribution from a 2.2.2

Power Flow

Radial distribution networks are usually designed for unidirectional Power flow 2.2.3 Protection Overcurrent protection schemes for radial distribution systems are designed based on the available 2.3

DISTRIBUTION SYSTEMS

Electric power systems that are 2.3.1 Review of Methods in Distribution Networks with Distributed Generation Fault location in a distribution system 2.4

REVIEW OF PROTECTION METHODS

The basis in designing 2.4.1

Distribution System Protection

The purpose of distribution 2.4.2 Review of Protection Coordination Methods With the presence

4

I.

Adaptive Protection Scheme for Distribution Networks

Adaptive protection is a relatively new which is defined as the ability of a protection system to automatically Adaptive protection is a relatively new which is defined as the ability of a protection system to automatically II.

Multi-Agent Protection Scheme for Distribution Networks

An agent is a computer system that is capable of performing autonomous actions in this environment to meet its design objectives 2.5

CHAPTER SUMMARY

This chapter presents an introduction of

CHAPTER III

3

3.1

AUTOMATED FAULT DIAGNOSIS IN A DISTRIBUTION NETWORK WITH DISTRIBUTED GENERATION

INTRODUCTION

This chapter describes the proposed 3.2

RADIAL BASIS FUNCTION NEURAL NETWORK

The RBFNN is a feed-forward neural network consisting of three layers, namely, an input layer 3.3

DISTRIBUTION NETWORK

An important consideration in 3.3.1 Network Prior to the RBFNN implementation, Adaptive protection is a relatively new which is defined as the ability of a protection system to automatically 3.3.2 Classification The second step is to identify 3.3.3 Location After identifying the fault type,

6

3.3.4 Determination After identifying the fault 3.3.5 Restoration Once the faulty line 3.3.6 Generation Before executing the fault 3.4

CHAPTER SUMMARY

An automated method have been developed

CHAPTER IV

4

4.1

PROTECTION COORDINATION STATEGY IN A DISTRIBUTION NETWORK WITH DISTRIBUTED GENERATION

INTRODUCTION

This chapter describes a novel protection 4.2

PROTECTION FUNDAMENTAL

Protective devices are operated to isolate 4.2.1 Main and Backup Main protection should 4.2.2 Device The protection coordination study involves the preparation of the one-line diagram of a power system, 4.3

ALGORITHM

The algorithm which is based on heuristics is an optimal search method satisfied. 4.4

PROPOSED STRATEGY

It is difficult to coordinate the

8

4.4.1 Main Protection Algorithm After identifying the 4.4.2 Backup Algorithm In case of misoperation of 4.5

CHAPTER SUMMARY

A new protection coordination strategy in a distribution network with DG units has been presented by

9

CHAPTER V

5

5.1

RESULTS AND DISCUSSION

RESULTS OF FAULT DIAGNOSIS USING RBFNN

The proposed fault diagnosis method using 5.1.1 Results for the 14 Bus Test System To verify the performance and accuracy of the proposed I.

Network

Before implementing fault II.

Generation and

The training and testing data III.

Results of Classification

To identify the various fault types IV.

Results of Location

After recognizing the fault type, V.

Results of Isolation

After identifying the fault type

10

VI.

Results of Restoration

Once the faulty line and the 5.1.2

Results for the 22 Bus Test System

A 22 bus, 20 kV distribution network with 2 DG units shown in Figure 5.3 is selected as the test system to verify the performance and accuracy of the proposed I. Network The 22 bus test system is divided into three zones as shown in Error! Reference source not found.. Zones 2 and 3 have one II. Generation The training data III. Results of Diagnosis Error! Reference source not found. shows the 5.1.3 Results for the 32 Bus Test System To verify the performance and accuracy of the proposed fault I. Network After performing the network zoning procedure, II. Generation The training data III. Diagnosis Results The fault diagnosis results

11

5.1.4 Comparison between RBFNN and MLPNN Results To further evaluate the effectiveness of 5.2

RESULTS OF STRATEGY

This section presents the results of the proposed 5.2.1 Results of Strategy for the 14 bus test system To verify the performance and accuracy of the proposed 5.2.2 Results of Strategy for the 22 bus test system The proposed 5.2.3 Results of Strategy for the 32 bus test system To verify the performance and accuracy of the proposed 5.3

CHAPTER SUMMARY

In this chapter,

CHAPTER VI

6

6.1

CONCLUSION AND FUTURE WORKS

CONCLUSION

In this thesis, 

To achieve the first objective of the research which is to the impact of



To address the second objective of the research which is to develop an automated

 6.2

The third objective is to develop a new SIGNIFICANT CONTRIBUTIONS OF THE RESEARCH

The major contributions of this thesis are summarized as follows: i.

The proposed method

ii.

The use

iii.

The proposed method

6.3

SUGGESTIONS FOR FUTURE WORK

The proposed techniques for i.

To explore the use of

ii.

To implement feature selection

REFERENCES

A Mohamed & M Mazumder 1999. A neural network approach to fault diagnosis in a distribution system. International Journal of Power & Energy Systems 19 (2): 129-134. Abdelaziz, A. Y., Talaat, H. E. A., Nosseir, A. I. & Hajjar, A. A. 2002. An adaptive protection scheme for optimal coordination of overcurrent relays. Electric Power Systems Research 61(1): 1-9. Baghzouz, Y. 2005. Voltage Regulation and Overcurrent Protection Issues in Distribution Feeders with Distributed Generation - A Case Study. 38th Annual Hawaii International Conference on System Sciences. 66b-66b. Bretas, A., Moreto, M., Salim, R. & Pires, L. 2006. A novel high impedance fault location for distribution systems considering distributed generation. IEEE PES Transmission and Distribution Conference and Exposition, Latin America, Venezuela. 1-6. Chaitusaney, S. & Yokoyama, A. 2005. Impact of protection coordination on sizes of several distributed generation sources. The 7th International Power Engineering Conference, (IPEC 2005) 669-674 Vol. 662. Cheung, H., Hamlyn, A., Cungang, Y. & Cheung, R. 2007. Network-based Adaptive Protection Strategy for Feeders with Distributed Generations. IEEE Canada Electrical Power Conference (EPC 2007). 514-519. Doyle, M. T. 2002. Reviewing the impacts of distributed generation on distribution system protection. Power Engineering Society Summer Meeting, 2002 IEEE. 1: 103-105 vol.101. El-Zonkoly, A. M. 2011. Fault diagnosis in distribution networks with distributed generation. Electric Power Systems Research 81(7): 1482-1490. Fei, W. & Ying, S. 2003. An Improved Matrix Algorithm for Fault Location in Distribution Network of Power Systems Automation of Electric Power Systems 24(3). Gaonkar, D. N. 2010. Distributed Generation. Croatia: InTech. Hui, W., Li, K. K. & Wong, K. P. 2010. An Adaptive Multiagent Approach to Protection Relay Coordination With Distributed Generators in Industrial Power Distribution System. IEEE Transactions on Industry Applications 46(5): 2118-2124.

APPENDIX A

RESULT OF FAULT DIAGNOSIS FOR THE 22 AND 32 BUS TEST SYSTEMS

Table A-1 Fault Diagnosis Results of the 22 bus test system Identify fault location

Sample

950 meter of line 1

200 meter of line 2

Fault type

RBFNN 1,3,5,7

RBFNN 2,4,6,8

Isolation

Restoration

RBFNN 3, 6, 9, 12

temporary

Distance from Main Source(Km)

Distance from DG1(Km)

Distance from DG2(Km)

Faulty Line No.

CB1

CB2

CB3

CB4

Recloser ‘1’

Close ‘1’

1 Ph-G

0.960

2.060

7.055

0.98

0

0

0

0

CB1

CB2-CB3-CB4

2 Ph

0.960

2.061

7.059

0.91

0

0

0

0

CB1

CB2-CB3-CB4

2 Ph-G

0.950

2.053

7.060

1.02

0

0

0

0

CB1

CB2-CB3-CB4

3 Ph

0.961

2.057

7.057

1.07

0

0

0

0

CB1

CB2-CB3-CB4

Actual

0.950

2.050

7.050

1

0

0

0

0

1 Ph-G

1.195

1.794

7.197

1.98

0

0

0

0

CB1

CB2-CB3-CB4

2 Ph

1.189

1.803

7.189

2.03

0

0

0

0

CB1

CB2-CB3-CB4

2 Ph-G

1.211

1.802

7.193

2.01

0

0

0

0

CB1

CB2-CB3-CB4

3 Ph

1.195

1.811

7.190

2.02

0

0

0

0

CB1

CB2-CB3-CB4

Actual

1.200

1.800

7.200

2

0

0

0

0 Continue …

… Continued

350 meter of line 3

450 meter of line 4

560 meter of line 5

1 Ph-G

2.347

0.643

8.351

3.03

1

0

1

0

CB2

DG1-CB4

2 Ph

2.352

0.657

8.344

3.01

1

0

1

0

CB2

DG1-CB4

2 Ph-G

2.361

0.656

8.346

3.09

1

0

1

0

CB2

DG1-CB4

3 Ph

2.355

0.647

8.351

3.05

1

0

1

0

CB2

DG1-CB4

Actual

2.350

0.650

8.350

3

1

0

1

0

1 Ph-G

3.450

0.453

9.442

4.01

1

1

1

0

CB4

CB4

2 Ph

3.449

0.458

9.449

3.98

1

1

1

0

CB4

CB4

2 Ph-G

3.450

0.452

9.448

4.00

1

1

1

0

CB4

CB4

3 Ph

3.451

0.456

9.447

4.02

1

1

1

0

CB4

CB4

Actual

3.450

0.450

9.450

4

1

1

1

0

1 Ph-G

4.560

1.562

10.554

4.96

1

1

1

0

CB4

CB4

2 Ph

4.559

1.555

10.553

4.92

1

1

1

0

CB4

CB4

2 Ph-G

4.560

1.559

10.561

5.02

1

1

1

0

CB4

CB4

3 Ph

4.558

1.556

10.556

5.08

1

1

1

0

CB4

CB4

Actual

4.560

1.560

10.560

5

1

1

1

0

APPENDIX B

MATLAB CODE clear all; clc; % determine network % DataNetwork_1; % DataNetwork_2; DataNetwork_3; % define faulted line Nline_fault = 2;