distributed generation allocation for power loss minimization and voltage improvement of radial ...

158 Pages·2014·2.13 MB·English

DISTRIBUTED GENERATION ALLOCATION FOR
POWER LOSS MINIMIZATION AND VOLTAGE
IMPROVEMENT OF RADIAL DISTRIBUTION
SYSTEMS USING GENETIC ALGORITHM

By
DIPANJAN SAMAJPATI

DEPARTMENT OF ELECTRICAL ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY, ROURKELA
ROURKELA-769008

© Copyright by Dipanjan Samajpati, 2014
DISTRIBUTED GENERATION ALLOCATION FOR POWER
LOSS MINIMIZATION AND VOLTAGE IMPROVEMENT OF
RADIAL DISTRIBUTION SYSTEMS USING GENETIC
ALGORITHM

A Thesis for the award of the degree of

Master of Technology
In
Electrical Engineering

NIT Rourkela

Submitted By:
Dipanjan Samajpati
(Roll no.: 212EE4253)

Under the esteemed guidance of
Dr. Sanjib Ganguly
Assistant Professor, EED

May, 2014
DEPARMENT OF ELECTRICAL ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY, ROURKELA
ROURKELA-769008
NIT Rourkela

CERTIFICATE
I hereby certify that the work which is being presented in the thesis
entitled “Distributed Generation Allocation For Power Loss
Minimization And Voltage Improvement Of Radial Distribution
Systems Using Genetic Algorithm” in partial fulfilment of the
requirements for the award of Master Of Technology degree in
Electrical Engineering submitted in Electrical Engineering
Department of National Institute of Technology, Rourkela is an
authentic record of my own work carried out under the supervision
of Dr. Sanjib Ganguly, Assistant Professor, Department of Electrical
Engineering.
The matter presented in this thesis has not been submitted for the
award of any other degree of this or any other university.

(Dipanjan Samajpati)
This is certify that the above statement made by candidate is correct
and true to best of my knowledge.
(Dr. Sanjib Ganguly)
Department of Electrical Engineering
National Institute of Technology, Rourkela
Rourkela -769008
This thesis is dedicated

To the soul of my Father and beloved Mother,
May God bless them and elongate them live in his
obedience!!

To my best friend Smarani,
May God bless her and give her a sweet, happy, deserving
trustful life!!

---Dipanjan Samajpati
ACKNOWLEDGMENTS

First and foremost, I am deeply obligated to Dr. Sanjib Ganguly my advisor and guide, for
the motivation, guidance, tutelage and patience throughout the research work. I appreciate his
broad range of expertise and attention to detail, as well as the constant encouragement he has
given me over the years. There is no need to mention that a big part of this thesis is the result
of joint work with him, without which the completion of the work would have been impossible.

Last but not least, I would like to express my deep thanks to my family and one of my best
friend for their unlimited support and encouragement. Their pray and love was my source and
motivation to continue and finish this research.

Dipanjan Samajpati
ABSTRACT

Numerous advantages attained by integrating Distributed Generation (DG) in distribution
systems. These advantages include decreasing power losses and improving voltage profiles.
Such benefits can be achieved and enhanced if DGs are optimally sized and located in the
systems. This theses presents a distribution generation (DG) allocation strategy to improve
node voltage and power loss of radial distribution systems using genetic algorithm (GA). The
objective is to minimize active power losses while keep the voltage profiles in the network
within specified limit. In this thesis, the optimal DG placement and sizing problem is
investigated using two approaches. First, the optimization problem is treated as single-objective
optimization problem, where the system’s active power losses are considered as the objective
to be minimized. Secondly, the problem is tackled as a multi-objective one, focusing on total
power loss as well as voltage profile of the networks. This approach finds optimal DG active
power and optimal OLTC position for tap changing transformer. Also uncertainty in load and
generation are considered. Thus, in this work, the load demand at each node and the DG power
generation at candidate nodes are considered as a possibilistic variable represented by two
different triangular fuzzy number. A 69-node radial distribution system and 52-node practical
radial systems are used to demonstrate the effectiveness of the proposed methods. The
simulation results shows that reduction of power loss in distribution system is possible and all
node voltages variation can be achieved within the required limit if DG are optimally placed in
the system. Induction DG placement into the distribution system also give a better performance
from capacitor bank placement. In modern load growth scenario uncertainty load and
generation model shows that reduction of power loss in distribution system is possible and all
node voltages variation can be achieved within the required limit without violating the thermal
limit of the system.
TABLE OF CONTENTS

ABSTRACT
Table of Contents vii
List of Tables x
List of Figures xii
List of Abbreviations and Symbols Used xvii
CHAPTER 1 Introduction and Literature Review 1-10
1.1 Introduction 1
1.2 Objective of the Work 4
1.3 Literature Review 5
1.3.1 Distribution Networks and Distributed Generation 5
1.3.2 Uncertainty in Distribution Planning 9
1.4 Organization of the Report 10
CHAPTER 2 Modelling and Allocation of DG in Distribution 11-16
Networks
2.1 Introduction 11
2.2 Distribution Network Power Losses 12
2.3 Distributed Generation 12
2.3.1 Operational And Planning Issues With DGs 12
2.3.2 DG Operation 13
2.3.3 DG Siting 14
2.3.4 DG Sizing 14
2.4 Summary 16
CHAPTER 3 Incorporation of DG Model in Distribution System 17-40
Load Flows
3.1 Introduction 17
3.2 Load Flow of Radial Distribution Systems 18
3.2.1 Equivalent Current Injection 19
3.2.2 Formation of BIBC Matrix 19
3.2.3 Formation of BCBV Matrix 21
3.2.4 Solution Methodology 24
3.3 Algorithm for Distribution System Load Flow 26
3.4 Incorporation of DG into Load Flow 28
vii
3.5 Incorporation of OLTC into Load Flow 29
3.6 Incorporation of CB into Load Flow 30
3.7 Algorithm for Distribution System Load Flow with DG 30
3.8 Test System 32
3.9 Load Flow Solution for Base Case 35
3.10 Summary 40
CHAPTER 4 Optimal DG allocation Using Genetic Algorithm 41-96
4.1 Introduction 41
4.2 Genetic Algorithm 41
4.2.1 GAs vs Conventional Algorithms 42
4.2.2 Genetic Algorithm Description 42
4.2.3 Parameters of GA 44
4.2.4 Algorithm of Basic GA 45
4.2.5 Applications of GA 47
4.3 DG Allocation Optimization Objective Function 48
4.4 Basic-GA Optimization for DG Allocation 49
4.4.1 Coding Scheme 50
4.4.2 Initialization 50
4.4.3 Fitness Function 52
4.4.4 Reproduction 52
4.4.5 Crossover 53
4.4.6 Mutation 55
4.4.7 Elitism 56
4.4.8 Genetic Control Parameters Selection 56
4.5 Algorithm for DG Allocation 57
4.6 Case Study for Basic GA Optimization 60
4.6.1 Selection of GA Parameter for DG Allocation 61
4.6.2 Single-Objective Optimization With Basic GA - 63
Results of First Approach 63
Results of Second Approach 70
4.6.3 Multi-Objective Optimization With Basic GA 74
4.7 Improved/Adaptive Genetic Algorithm (IGA) 78
Optimization
4.7.1 Algorithm of Adaptive GA 80
viii
4.8 Case Study Adaptive Genetic Algorithm Optimization 82
4.8.1 Case Study for Adaptive GA#3 Optimization 83
4.9 Proposed Adaptive-GA Optimization 89
4.10 Case Study for Selection of Uncrossed Parents 94
4.11 Summary 96
CHAPTER 5 Optimal DG Allocation Under Variable Load and 97-123
Generation Using Genetic Algorithm
5.1 Introduction 97
5.2 Multi-Objective Planning of Radial Distribution 98
Networks Using PLGM
5.2.1 Possibilistic Load and Generation Model (PLGM) 99
5.2.2 Comparison of Fuzzy Numbers 100
5.3 Objective Functions 101
5.4 DG Allocation Strategy Using GA 102
5.5 Case Study for Uncertainty in Load and Generation 105
5.5.1 Deterministic load and generation analysis 105
5.5.2 Possibilistic load and generation analysis 108
5.5.3 Multiple run for deterministic and possibilistic load 109
and generation
5.5.4 Multiple run uncertainty analysis with different 115
system and GA parameter
5.5.5 Multiple run uncertainty analysis with different DG 117
rating limit
5.5.6 Violation of system constraint in overloading 119
condition
5.6 Summary 123
CHAPTER 6 Conclusion and Scope for Future Work 124-127
6.1 Conclusions 124
6.2 Scope for Future Work 127
REFERENCES 128-137
RESEARCH PUBLICATIONS 138
APPENDIX A 139-142
ix
LIST OF TABLES

Table 3.1 Base case converged flow solution for system #1. 38
Table 3.2 Base case converged flow solution for system #2. 39
Table 4.1 GA parameter selection with system#1 62
Table 4.2 Base case converged cower flow solution for system #1. 63
Table 4.3 Comparison of various cases optimization operation 64
Table 4.4 Converged Power Flow Solution of case#1(a); case#1(a), 67
unity p.f. DG
Table 4.5 Converged Power Flow Solution of case#2(a); case#2(a), 68
unity p.f. DG and OLTC
Table 4.6 Optimal Power Flow Solutions for 10 run. 69
Table 4.7 Comparison of various cases optimization operation. 70
Table 4.8 Converged Power Flow Solution for 10 run. 73
Table 4.9 GA and network parameters considered for the optimization 74
process
Table 4.10 Multiple run solution for different case with system#2 76
Table 4.11 Multi-objective optimization for different system with basic 77
GA optimization
Table 4.12 Comparison of various GA optimization for DG allocation 82
with system#1
Table 4.13 Different case study for different system with GA#3 88
optimization
Table 4.14 Position and rating for DG and CB of GA#3 optimization in 88
different cases
Table 4.15 Different case study for different system with GA#6 93
optimization
Table 4.16 Comparison of various uncrossed parents selection approach 94
of GA optimization for dg allocation
x