i effect of various load on power system...
TRANSCRIPT
i
EFFECT OF VARIOUS LOAD ON POWER SYSTEM PROTECTION
SUN RUIHAO
A project report submitted in partial fulfilment of the
requirements for the award of the degree of
Master of Engineering (Electrical-Power)
Faculty of Electrical Engineering
Universiti Teknologi Malaysia
JANUARY 2012
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DEDICATION
To my beloved mother and father
谨此献给含辛茹苦的，我所爱的父母
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ACKNOWLEDGEMENTS
ACKNOWLEDGEMENTS
I would like to express my sincere gratitude to my supervisor Prof. Ir. Dr.
Abdullah Asuhaimi bin Mohd Zin for him continuous guidance, advice and support.
Besides, I would like to thank some of my local friends. Thanks for them give me
lots of ideas and help in my study, and give me a wonderful life in UTM.
Finally, I would like to extend special word of appreciation to the most important
person in my life: my dear father SUN JUN, and my lovely mother YAN YU, for
their endless love and selfless support to allow me further study in Malaysia.
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ABSTRACT
ABSTRACT
This project established a reclosing simulation mode on 161kv line with
bilateral power source of regional network based on PSCAD, and to do the
simulation when the different types of fault occur on the various load condition. On
this basis, analysis for the different types of fault occur is done, and effect of various
loads of the protection devices in the power system is studied. The key point analysis
focused on the effect of residue voltage produced from the induction motor load in
case of the transient fault and permanent fault occurred on the transmission line
separately.
This thesis has analyzed the changing rule of the residual voltage produced
from the induction motor when the faults occurred. Hence, a proper reclosing time
was identified, and a better control system, which able to improve the residual
voltage on the power system protection, was proposed.
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ABSTRAK
ABSTRAK
Projek ini bertujuan untuk mensimulasikan sumber kuasa elektrik rangkaian
serantau dua hala 161kV dengan menggunakan PSCAD. Kajian ini adalah hasil
simulasi mod “reclosing” pada sistem talian penghantaran 161kV ke atas jenis
keadaan beban yang berlainan. Simulasi ini juga mengesahkan pelbagai kesilapan
atau kegagalan yang mungkin boleh berlaku kepada sistem. Oleh itu, analisis ini
dibuat berdasarkan pelbagai kesan beban peranti perlindungan dalam sistem kuasa.
Analisis tertumpu kepada kesan voltan yang dihasilkan daripada beban yang
berdasarkan motor induksi dalam kes kesalahan fana dan kerosakan tetap yang
berlaku dalam talian penghantaran secara berasingan.
Tesis ini telah menganalisis perubahan peraturan voltan yang dihasilkan
daripada motor induksi apabila kesalahan berlaku. Oleh itu, masa yang sesuai untuk
“reclosing” telah dikenal pastikan. Selain itu, sistem kawalan yang lebih baik, di
mana dapat meningkatkan voltan baki perlindungan sistem kuasa, telah dicadangkan.
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TABLE OF CONTENTS
1 INTRODUCTION 1
1.1 Background
1.2 Problem Statement
1.3 Objectives
1.4 Scope
1.5 Thesis Outline
1
3
4
4
4
2 LITERATURE REVIEW 6
2.1 Introduction
2.2 Faults on Power System
2.3 Acuter Event
6
6
8
CHAPTER TITLE PAGE
DECLARATION
DEDICATION
ACKNOWLEDGEMENT
ABSTRACT
ABSTRAK
TABLE OF CONTENTS
LIST OF TABLES
LIST OF FIGURES
LIST OF ABBREVIATIONS
LIST OF APPENDICES
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2.3.1 Fault Arc Path and Effect on Motor
2.4 Distance Relay
2.5 Auto-Recloser
2.5.1 Setting Reclosing Time
2.6 Induction Motor and Residue Voltage
2.6.1 The Theory Analysis of Induction Motor
Residue Voltage
2.6.2 Research on Residue Voltage
2.7 Summary
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10
11
13
16
19
20
23
3 METHODOLOGY 24
3.1 Introduction
3.2 Process Analysis
3.3 Circuit Construction
3.4 Components
3.4.1 Source
3.4.2 Multimeter
3.4.3 Transmission Line
3.4.4 Circuit Breaker
3.4.5 Fault Component
3.4.6 Induction Motor
3.4.7 Online Frequency Scanner
3.4.8 Distance Relay
3.5 Summary
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27
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4 RESULTS AND DISCUSSIONS 39
4.1 Introduction
4.2 No Fault Condition
4.3 Transient Fault Condition
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39
41
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4.3.1 Transient Fault without Motor Load
Condition
4.3.2 Transient Fault with Induction Motor
Load Condition
4.4 Permanent Fault Condition
4.4.1 Permanent Fault without Motor
Load Condition
4.4.2 Permanent Fault with Motor Load
Condition
4.5 Summary
42
46
56
56
59
67
5 CONCLUSIONS AND RECOMMENDATIONS 68
5.1 Conclusions
5.2 Recommendation
68
69
REFERENCES 70
APPENDIX A 72
x
LIST OF TABLE
TABLE NO.
2.1
TITLE
Main Parameter of Induction Motor
PAGE
22
3.1 Configuration of Voltage Source
27
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LIST OF FIGURES
FIGURE NO. TITLE PAGE
1.1 The typical load on transmission line network 3
2.1 The Photo of the fault type on transmission line 7
2.2 One-line of Monsanto-Johnsonville 161kv line 8
2.3 Power Quality data captured during unsuccessful
high-speed reclose.
8
2.4 3-Zone distance protection scheme 11
2.5 The typical operational settings of auto-recloser 12
2.6 Principle diagram of synchronous reclosing 14
2.7 Diagram of ΔU and δ on synchronism check relay 16
2.8 Auto-reclosing on lines with motors 17
2.9 Induction motor equivalent circuit. 21
2.10 Residual voltage and rotor current oscillogram in single
motor
21
2.11 Simulating model of reclosing for induction machine 22
2.12 Result of simulating 22
3.1 The schematic diagram of project flow 25
3.2 Establishment of 161 kV line reclosing on without
motor load
26
3.3 Establishment of 161 kV line reclosing on induction
motor load.
26
3.4 Three Phase Voltage Source 27
3.5 Multimeter 28
3.6 Transmission Line 28
3.7 The Type of Transmission Tower 30
3.8 Parameters of Line Model 30
3.9 Circuit Breaker 30
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3.10 Three Phase Fault 31
3.11 The Fault Type 31
3.12 Squirrel Cage Induction Machine 32
3.13 The induction motor definition by CSMF 32
3.14 Online Fast Fourier Transform (FFT) 33
3.15 Distance relay design by PSCAD 34
3.16
3.17
3.18
3.19
3.20
3.21
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
4.12
4.13
The control part of Distance relay
The Distance relay definition by CSMF
Line to Ground Impedance Component
The Distance relay definition by CSMF
Line to Line Impedance Component
MHO Circle Component
No Fault Condition
Without motor load condition model by PSCAD
Signal Phase Fault without Motor Load Condition
Signal Phase Fault without Motor Load Condition
Induction motor load condition model by PSCAD
Three Phase Fault without Motor Load Condition
Three Phase Fault with Induction Motor Load
Condition
Three Phase Fault with Induction Motor Load
Condition
Three Phase Fault with Induction Motor Load
Condition
Permanent Fault without Motor Load Condition
Permanent Fault without Motor Load Condition
Permanent Fault without Motor Load Condition
Permanent Fault with Motor Load Condition
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62
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4.14 Permanent Fault with Motor Load Condition 66
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LIST OF ABBREVIATIONS
Ea - Voltage Source
Ia - Current phase a
UV - Under-Voltage
OV - Over-Voltage
TEF - Transient Energy Function
KV - Low Voltage Element
KY - Synchronous Element
AAR - Auto-Recloser
MATLAB - Math Lab
W - Motor Speed
CSMF - Continuous System Model Function
FFT - Fast Fourier Transform
MAG - Magnitude
PH - Phase
PSCAD - Power System CAD
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LIST OF APPENDICES
APPENDIX PAGE
A Output of Channels 72
1
CHAPTER 1
1 INTRODUCTION
INTRODUCTION
1.1 Background
Electrical energy is the most popular form of energy due to it can be
transported easily at high efficiency and reasonable cost [1]. The modern power of
engineering consists of three main subsystems, which are generation, transmission
and distribution. In order to provide the electrical energy to consumer in usable form,
the transmission and distribution system have to be satisfying some of the basic
requirements, which are shown as below [2]:
i. Provide the power consumers needed for all the time.
ii. Maintain a stable and nominal voltage that does not vary by more than
+10%.
iii. Maintain a stable frequency that does not vary by more than +0.1 Hz.
iv. Supply energy at an acceptable price.
v. Meet the standard of safety.
vi. Follow the environmental standards.
Transmission line in power system is an important component, where it is
used to transmit the power. The operation experiences the power of system shows
that the faults occurred on transmission lines are mostly transient; hence the
automatic recloser is widely used in transmission line. It is a very important
equipment to guarantee the security of operation power line and improve the
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reliability of power supply. Besides, it is an effective method to improve the stability
and reliability of power systems. However, the present auto-recloser technique
normally employs a prescribed reclosing time, which is the breaker will be re-closed
after a fixed period following a tripping operation.
In the industrial production sectors, medium and large induction motors have
been widely used, often used as an important auxiliary production. Its capacity can
reach up to thousands of kilowatts, no matter the operations can reclose or cannot; all
the consequence can affect the entire production process. Once the electrical outage
for any reason, it will cause great loss of production [1-2].
In practice, when the transient fault occurred, the produce of the short-term
depression on power supply, which led to the protection device tripped, and make the
loss of motor power is a common phenomenon. Luckily, this failure is usually
temporary, and let the motor rapidly recover the power supply after short-term outage;
hence the production loss can be reduced. This requires a temporary reclose after
troubleshooting operations to ensure the normal operation of the motor [3-5].
The various components constitute in the power system, the transmission
lines have a wide working area and can support a variety of natural conditions and
the rate of failure is the highest in all electrical equipment. Therefore, the protection
of normal transmission line operation is an important task in the power system. The
installation of auto-recloser is to ensure the rapid restoration if necessary, and to
protect the circuit during normal operation.
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1.2 Problem Statement
Weak
SourceE F
A D
BC
Pulp and
paper mill
(motor)
Utility
161 kV
Utility
161 kV
Strong
Source
Figure 1.1: The typical load on transmission line network
With reference to Figure 1.1, points E and F are circuit breakers which are
installed with protective device, first to assume there without motor load, when faults
occur on the transmission line the utility protective relays at each end detect the fault
and initiate tripping of their respective breaker. Breakers E and F will trip. Protection
device at E will operate in the dead line live bus condition, followed by F. After the
protective device E operates, the transmission line become live, the protective device
F will be reclose during this condition.
In reality, there are large motor loads connected to transmission line. When
the faults occur in the transmission line, the supply is removed from an induction
machine, flux is trapped in its rotor. This flux decays with time and produces a
residual voltage in the machine windings until its rotation ceases. Residual voltage
can decay in a few cycles in small machines but may require up to five seconds in
larger machines. Higher inertia machines will tend to act as generators feeding the
lower inertia machines on the bus such that the entire group decays together. Means
that the motor load will become generator which supply power to grid. The power
will be supplied from strong source to weak source, so the problem is to optimize the
protective device setting in the system, which can work normal conduction in live
line live bus condition.
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1.3 Objective
The objectives of this study are:
(i) To study the performances of protective device operate safely and
successfully during various load condition.
(ii) To study the residual voltage generated by induction motor.
(iii) To propose some protection elements to decrease the effect of residual
voltage on power system.
1.4 Scope
The two main goals of a transmission line protection scheme are to
successfully clear faults and to successfully reclose the circuit once when fault has
been cleared. The chances of success are greatly reduced in the presence of
significant induction motor load. The presence of motor load, can affect the system
protection, so must proper scheme adjustments could be made.
The scopes of the project are as below:
(i) The various load condition effect on the transmission line reclosing
will be studied.
(ii) In this project, the protection elements setting will be considered.
(iii) The modeling and simulation using power system CAD software.
1.5 Thesis Outline
First chapter is briefly introducing protective devices which are used in
transmission line and a general idea about the project. This chapter discusses about
the main objectives, scope, problem statement and describes the project methodology
that will be used.
5
Second chapter is written based on the finding from literature review. This
chapter elaborates about protective device used related with induction motor of
transmission line, and the residue voltage generated by induction motor. It is about
the basic theory or general topic related this project.
Third chapter is mainly discussed the methodology and the background of the
project.
Fourth chapter is to describe the simulation and results of the design using
PSCAD consist of the components.
Fifth chapter is the conclusion and also the last chapter concludes the project
and highlights some of the recommendation to improve the project.
70
REFERENCE
REFERENCE
1. Abdullah Asuhaimi Bin Mohd. Zin, “Power system protection” 2010.
2. Hadi Saadat, “Power System Analysis” McGraw Hill, 2004.
3. Les Hewitson, “Practical Power Systems Protection” Pearson Prentice Hall,
2004.
4. Russell W. Patterson George T. Pitts, “Reclosing and Tapped Motor Load”
61st Annual Georgia Tech Protective Relaying Conference May 2-4, NY,
2007
5. LI Yi feng, “Discussions for Setting Reclosing Time of Transmission Lines”
The Information College of Guangdong Ocean University, Journal of
Guangdong University, Zhanjiang 524088, China, 2007.
6. Kuo-HsiungTseng, Wen-ShiowKao, and Jia-Renn Lin, “Load Model Effects
on Distance Relay Settings”, IEEE transactions on power delivery, VOL. 18,
NO. 4, October 2003, 13(1):21-24.
7. Shaltout A, Al-omoush M, “Reclosing torques of large motors with stator
trapped flux”, IEEE Transactions on Energy Conversion, 1996, 11(1):84-90.
8. Deng Jianguo, “Transient analysis on reclosing of three-phase motor”,
Electric power Automation Equipment, 2004, 24(1):37-41.
9. J. Berdy and P. G. Brown, “High-Speed Reclosing Systemand Machine
Considerations” IEEE Transactions on Energy Conversion, NY. 2009, 42(2).
10. Meyer Kao Tennessee Valley, “Analysis of Underfrequency Load Shedding
and Reclosing into a Motor Load on a TVA 161 kV Transmission Line”.
Authority Presented to the Georgia Tech Fault and Disturbance Analysis
Conference May 1-2, 2006.
11. Ma Hongzhong, Hu Qiansheng, Zhang Lim in, Han Jingdong, “Research on
Residua l Voltage of AC Motor after Dump” S&M Electric Machines, 2005,32
(5):3-5.
12. Line Protection Subcommittee Working Group D5 of the IEEE Power
71
Engineering Society, “Summary of C37.230-2007, IEEE Guide for Protective
Relay Applications to Distribution Lines”, Power System Relaying
Committee. 2006, 17(1).
13. Zhang baohui, “Optimal reclosing time and its setting calculation” IEEE
Transactions on Energy Conversion, China. 2009.
14. Xie Kefu, “Transient Analysis of Three -phase Induction Motor with
Momentary Voltage Dips”, Journal of Zhejiang University ( Engineering
Science), China. 2003.
15. G.E Alexander and J.G Andrichak, “Ground Distance Relaying: Problems
and Principles”, General Electric Company Malvern, PA, 1991
16. Yu Ji Akiyama, member, IEEE, “Induction Motor Residual Voltage”
Kanagawa Institute of Technology, JAPAN, 2002.
17. Aiyuan Wang, Zhihao Ling, Wenbo Liu,“ Residual Voltages Analysis in
Reclosing Process for Induction Machine”, Proceedings of the 7th
World
Congress on Intelligent Control and utomation June 25 - 27, Chongqing,
China, 2008,