Optimal Allocation of FACTS Devices in Power Networks Using Imperialist Competitive Algorithm

209 Pages·2015·3.66 MB·English

Optimal Allocation of FACTS Devices
in Power Networks Using Imperialist
Competitive Algorithm (ICA)

A thesis submitted for the degree of Doctor of Philosophy

By

Mohammad Shahrazad

Supervised by Dr. Ahmed F Zobaa
College of Engineering, Design and Physical Sciences
Brunel University London

September 2015
ABSTRACT
Due to the high energy consumption demand and restrictions in the installation of new
transmission lines, using Flexible AC Transmission System (FACTS) devices is inevitable. In
power system analysis, transferring high-quality power is essential. In fact, one of the
important factors that has a special role in terms of efficiency and operation is maximum
power transfer capability. FACTS devices are used for controlling the voltage, stability,
power flow and security of transmission lines. However, it is necessary to find the optimal
location for these devices in power networks. Many optimization techniques have been
deployed to find the optimal location for FACTS devices in power networks.
There are several varieties of FACTS devices with different characteristics that are
used for different purposes. The imperialist competitive algorithm (ICA) is a recently
developed optimization technique that is used widely in power systems. This study presents
an approach to find the optimal location and size of FACTS devices in power networks using
the imperialist competitive algorithm technique. This technique is based on human social
evolution. ICA technique is a new heuristic algorithm for global optimization searches that is
based on the concept of imperialistic competition. This algorithm is used for mathematical
issues; it can be categorized on the same level as Genetic Algorithm (GA) and Particle
Swarm Optimization (PSO) techniques. Also, in this study, the enhancement of voltage
profile, stability and loss reduction and increasing of load-ability were investigated and
carried out. In this case, to apply FACTS devices in power networks, the MATLAB program
was used. Indeed, in this program all power network parameters were defined and analysed.
IEEE 30-bus and IEEE 68-bus with 16 machine systems are used as a case study. All the
simulation results, including voltage profile improvement and convergence characteristics,
have been illustrated. The results show the advantages of the imperialist competitive
algorithm technique over the conventional approaches.
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ACKNOWLEDGEMENTS

I would like to express my utmost gratitude to Dr. Ahmed Zobaa for initiating this
research and for his guidance and encouragement throughout the duration of my research into
this topic.
I gratefully acknowledge my brother who supported me financially during my course.
I would like to thank my lovely fiancée for all her support and love.

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DECLARATION

The work described in this thesis has not been previously submitted for a degree at
this or any other university and unless otherwise referenced it is the author’s own work.

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To my:

Dad & Mum

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STATEMENT OF COPYRIGHT

The copyright of this thesis rests with the author. No parts from it should be published
without his prior written consent, and information derived from it should be acknowledged.
©COPYRIGHT Mohammad Shahrazad
All Rights Reserved

LIST OF JOURNAL PUBLICATIONS

1. Mohammad Shahrazad, Ahmed Zobaa, “Optimal Allocation of FACTS Devices in
Distribution Networks Using Imperialist Competitive Algorithm”, International
Review of Electrical Engineering (I.R.E.E.), 2013, Vol. 8, No. 5
2. Mohammad Shahrazad, Amirhessam Alikhanzadeh, “Application of Imperialist
Competitive Optimization Algorithm in Power Industry”, International Journal of
Industrial Engineering Computations, 2015, Vol. 6, No. 1
3. Mohammad Khodapanah, Mohammad Shahrazad, “Combination of Energy Storage
and Wind Turbine with Conventional Generation Using Scheduling Technique”,
International Journal of Electronics and Electrical Engineering, 2015, Vol. 3, No. 6
4. Yaminidhar Reddy Bhavanam, Mohammad Shahrazad, “Impact of Increased
Distributed Generation on Fault Levels and the Network Equipment”, Journal of
Electrical Systems, 2014, Vol. 10, No. 2

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Contents
Abstract .................................................................................................................................................................. i
Acknowledgements ............................................................................................................................................... ii
Declaration ........................................................................................................................................................... iii
Statement of Copyright ........................................................................................................................................ v
List of Journal Publications ................................................................................................................................. v
List of Figures ....................................................................................................................................................... x
List of Tables ...................................................................................................................................................... xiii
List of Symbols .................................................................................................................................................... xv
List of Abbreviations ......................................................................................................................................... xvi
1.Introduction
............................................................................................................................................ 2
1.1.Power Systems Environment .......................................................................................... 2
1.2.FACTS Devices
...................................................................................................................... 2
1.3.Power Networks
..................................................................................................................... 3
1.4.Research Aim and Objectives ........................................................................................ 3
1.5.Principle Contribution to Knowledge ........................................................................ 4
1.6.Research Methodology ....................................................................................................... 4
1.7.Thesis Outline .......................................................................................................................... 5
2.FACTS Devices
................................................................................................................................. 8
2.1.FACTS Background
............................................................................................................. 8
2.2.Available transfer capability
........................................................................................... 9
2.3.Importance of FACTS
....................................................................................................... 12
2.4.FACTS Device Investment
............................................................................................ 14
2.5.Category and Types of FACTS
................................................................................... 16
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2.5.1.Parallel Device Compensator ................................................................................................ 17
2.5.1.1.Static Var Compensator .......................................................................................... 17
2.5.1.1.1.Thyristor Controlled Reactor ............................................................................... 19
2.5.1.1.2.Thyristor switched Reactor .................................................................................. 20
2.5.1.1.3.Thyristor Switched Capacitor .............................................................................. 21
2.5.1.2.Static Synchronous Compensator ........................................................................... 22
2.5.2.Series Device Compensator .................................................................................................. 24
2.5.2.1.Thyristor Switched Series Capacitor ....................................................................... 24
2.5.2.2.Thyristor Controlled Series Capacitor .................................................................... 25
2.5.2.3.GTO Controlled Series Capacitor ........................................................................... 28
2.5.2.4.Static Synchronous Series Compensator ................................................................. 29
2.5.3.Series-Series Device Compensators ...................................................................................... 29
2.5.3.1.Inter Line Power Flow Controller ........................................................................... 29
2.5.4.Series-Parallel Device Compensators ................................................................................... 30
2.5.4.1.Unified Power Flow Controller ............................................................................... 30
2.5.4.1.1.UPFC Structure .................................................................................................... 31
2.5.4.1.2.Operation of UPFC .............................................................................................. 32
2.5.4.1.3.Physical Operation of UPFC ................................................................................ 33
2.5.4.1.4.UPFC Control Modes .......................................................................................... 34
2.5.4.1.4.1.Parallel Converter ............................................................................................. 35
2.5.4.1.4.2.Series Converter ................................................................................................ 35
2.5.4.1.5.UPFC Constraints ................................................................................................ 36
2.5.4.2.Thyristor Controlled Phase Shifting Transformer ................................................... 37
2.5.5.Advantages of SVC and UPFC in Power Networks.............................................................. 38
2.6.Summary of the Chapter
.................................................................................................. 40
3.Literature Review
........................................................................................................................... 43
3.1.Genetic Algorithm
............................................................................................................... 84
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3.2.Particle Swarm Optimization
........................................................................................ 85
3.3.Bees Algorithm
..................................................................................................................... 85
3.4.Imperialist Competitive Algorithm
........................................................................... 86
4.Imperialist Competitive Algorithm
................................................................................. 88
4.1.Optimization Overview
.................................................................................................... 88
4.2.Types of Optimization Problems ................................................................................ 90
4.2.1.Trial and Error Optimization ...................................................................................... 90
4.2.2.Single- and Multiple-Dimension Optimizations.................................................................... 91
4.2.3.Dynamic and Static Optimizations ........................................................................................ 91
4.2.4.Discrete and Continuous Optimization ................................................................................. 91
4.2.5.Constrained and Unconstrained Optimization ....................................................................... 92
4.2.6.Minimum-Seeking and Random Optimization ..................................................................... 92
4.2.7.Optimization Outline ............................................................................................................. 92
4.3.Imperialist Competitive Algorithm Background............................................... 93
4.3.1.Imperialist Competitive Algorithm .......................................................................... 93
4.3.2.Performing Initial Empires ......................................................................................... 96
4.3.3.Assimilation and Moving Colonies towards the Empires .................................. 98
4.3.4.Swapping the Positions of the Colony with the Imperialist .............................. 99
4.3.5.Total Power of Imperialist ........................................................................................ 100
4.3.6.Imperialist Competition ............................................................................................. 100
4.3.7.Weak Empires Collapse ............................................................................................. 103
4.4.Summary of the Chapter ................................................................................................ 106
5.Optimization problem
............................................................................................................... 108
5.1.IEEE 30-Bus System ....................................................................................................... 108
5.1.1.Total Transfer Capability .......................................................................................... 109
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5.1.2.Objective Functions and Constraints ..................................................................... 110
5.1.2.1.UPFC Modeling ........................................................................................................ 111
5.2.IEEE 68-Bus System ....................................................................................................... 115
5.2.1.Objective Functions and Constraints ..................................................................... 115
5.3.Summary of the Chapter ................................................................................................ 117
6.Results and Discussions
.......................................................................................................... 119
6.1.IEEE-30 Bus System without FACTS .................................................................. 120
6.1.1.P-V Curves .................................................................................................................... 127
6.2.IEEE 30-Bus System with Static Var Compensator ..................................... 131
6.3.IEEE 30-Bus System with Unified Power Flow Controller ..................... 145
6.4.Results Comparison .......................................................................................................... 152
6.5.IEEE 68-Bus System ....................................................................................................... 157
6.5.1.Allocation of SVC in the Study Case .................................................................... 157
6.6.Summary of the Chapter ................................................................................................ 162
7.Conclusions
........................................................................................................................................ 165
7.1.Future Work .......................................................................................................................... 166
References ................................................................................................................................................... 168
Appendix A ................................................................................................................................................. 180
Appendix B ................................................................................................................................................. 184

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