SETTING AND COORDINATION OF OVERCURRENT RELAY IN
DISTRIBUTION SYSTEM
ABDUL HADI BIN ISMAIL
Submitted to the Faculty of Electrical Engineering
in partial fulfillment of the requirement for the degree of
Bachelor in Electrical Engineering (Power)
Faculty of Electrical Engineering
Universiti Teknologi Malaysia
MAY 2008
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Dedicated, in thankful appreciation for support, encouragement and understandings
to:
My beloved mother Halijah Bte Ibrahim and father Ismail Bin Awang;
my brother and sister Norhasanah, Ahmad Tarmizi, Mohd Lotfi, Khairul Anwar
and Muhammad Naim;
also my beloved friend Ridhuan, Aidil, Rushdi, Afizan, Mohd Al-amin, Azizi and
Noor Izyawati Ibrahim
and all person contribute to this project.
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ACKNOWLEDGEMENT
First of all I would like to take this opportunity to express my sincere to Hjh
Faridah bt Hussin for his numerous invaluable advice, comments, guidance and
persistence encouragement throughout the course of this project.
My sincere appreciation also goes to Encik Hashim b Ahmad Turki (Branch
Manager, TNBD Langkawi) for his idea and advice to complete this project.
I would also like to thank our Advance Power Lab Technician, Puan Norlela for her
co-operations, guidance and helps in this project.
My appreciation also goes to my family who has been so tolerant and supports me
all these years. Thanks for their encouragement, love and emotional supports that they had
given to me.
Nevertheless, my great appreciation dedicated to my friends and those whom
involve directly or indirectly with this project. There is no such meaningful word
than...Thank You So Much.
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ABSTRACT
This project mainly focuses on studies of protection relay in power distribution
system. Relay that used in this project is inverse definite minimum time relay (IDMT)
and its have a widely application in distribution system. The reliability of power system
can be increased by proper setting and coordination of the relays in power distribution
system. The characteristic of relay is analyzed to find out the operating condition and
setting of the relay. A case study of power distribution system in Universiti Teknologi
Malaysia is analyzed and simulated using SKM Power Tools software to find out the
setting and coordination of a relay. Using relay coordination concept that are discussed
in this project, the operating time of relay for distribution system can be analyzed and
developed.
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ABSTRAK
Projek ini memfokuskan mengenai geganti perlindungan yang digunakan di
dalam sistem pengagihan. Geganti yang digunakan dalam projek ini adalah geganti
masa minimum tertentu songsang yang banyak diaplikasikan di dalam sistem
pengagihan. Keboleharapan di dalam sistem kuasa juga boleh ditingkatkan oleh
pengesetan dan koordinasi yang betul dalam sistem pengagihan kuasa elektrik. Ciri-ciri
geganti telah dianalisis untuk mendapatkan pengesetan dan keadaan operasi geganti
tersebut. Sistem pengagihan Universiti Teknologi Malaysia digunakan sebagai kajian
untuk dianalisis dan simulasi menggunakan perisian SKM Power Tools untuk
mendapatkan pegesetan dan koordinasi geganti aruslebih. Berdasarkan konsep
koordinasi untuk geganti aruslebih yang dibincangkan dalam projek ini, masa operasi
bagi geganti aruslebih di dalam sistem pengagihan dapat dihasilkan dan dianalisis.
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TABLE OF CONTENT
CHAPTER TITLE PAGE
DECLARATION OF THESIS ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENT vii
LIST OF TABLES x
LIST OF FIGURES xi
LIST OF SYMBOLS xii
LIST OF APPENDICES xiii
1. INTRODUCTION 1.1 Problem Statement 1
1.2 Objectives 2
1.3 Scope of Work 2
1.4 Organization of The Thesis 4
2. POWER SYSTEM PROTECTION 2.1 Introduction 5
2.2 Protection for Power Distribution System 6
2.3 Protection Devices 6
2.3.1 Fuse 6
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2.3.2 Circuit Breaker 7
2.3.3 Relay 7
2.4 Relays 7
2.4.1 Induction Relays 8
2.4.2 Attracted-armature Relays 9
2.4.3 Moving coil Relays 10
2.4.4 Thermal Relays 11
2.4.5 Timing Relays 11
2.4.6 Static Relays 12
2.5 Requirements 13
2.6 Protective Relay Application in Electrical Network 13
2.7 Protective Relaying 14
2.7.1 Applications 14
2.7.2 System 15
2.7.3 Scheme 16
2.8 Relay Coordination Concept 17
2.8.1 Radial System 17
2.8.2 Ring System 17
2.9 Overcurrent relay 18
2.9.1 Overcurrent Protection 18
2.9.2 Overcurrent IDMT Type Relays 19
2.10 Overcurrent Schemes 19
2.10.1 Shortcomings 19
2.10.2 Overcurrent Relay in a Distribution System 20
2.11 Time-graded Overcurrent Protection 20
2.11.1 Settings 21
2.11.2 Time Multiplier Setting 21
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3 SOFTWARE 3.1 Introduction 23
3.2 SKM Power Tools for Windows 24
3.2.1 DAPPER 24
3.2.2 CAPTOR 26
3.3 SKM in Relays Coordination 26
3.3.1 Modeling 27
3.3.2 Simulation and Analysis 27
3.3.3 Coordination 27
3.3.4 Evaluation 28
4 RESULT AND DISCUSSION 4.1 Introduction 31
4.2 Result of Simulation for Zon 1 32
4.2.1 Result for Overcurrent Relay Setting in Zon 1 37
4.2.2 Different setting of Time Setting Multiplier 40
(TSM) in Zon 1
4.3 Result of Simulation for Zon 2 42
4.3.1 Result for Overcurrent Relay Setting in Zon 2 47
4.3.2 Different setting of Time Setting Multiplier 50
(TSM) in Zon 2
4.4 Discussion 53
5 CONCLUSION AND RECOMMENDATION 5.1 Conclusion 54
5.2 Recommendation 55
REFERENCES 56
APPENDICES 57
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LIST OF TABLES
TABLE TITLE PAGE
4.1 Setting of overcurrent relay in Zon 1, UTM 37
4.2 Setting of overcurrent relay in Zon 1, UTM 40
(Different setting of TSM)
4.3 Setting of overcurrent relay in Zon 2, UTM 47
4.4 Setting of overcurrent relay in Zon 2, UTM 51
(Different setting of TSM)
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LIST OF FIGURES
FIGURE TITLE PAGE
1.1 Simple Circuits in Distribution System 2
1.2 Project Overview 3
2.1 Induction relays 9
2.2 Circuit of Time Graded Scheme 15
2.3 Relay coordination concepts for ring 18
System
2.4 Standard IDMT current-time characteristic 22
3.1 Component editor function 25
3.2 Relay adder, shifter, and calibration points 28
Function
3.3 Setting of IDMT overcurrent relay 29
3.4 Single Line Diagram of UTM 30
Power Distribution
4.1 Single line diagrams for Zon 1, UTM 32
4.2 Single line diagrams for Zon 1, UTM using 34
SKM Power Tools
4.3 Current-time graphs for Zon 1, UTM 35
4.4 Current-time graphs for different 36
Setting of TSM in Zon 1, UTM
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4.5 Single line diagram for Zon 2, UTM 42
4.6 Single line diagrams for Zon 2, UTM using 44
SKM Power Tools
4.7 Current-time graph for Zon 2, UTM 45
4.8 Current-time graphs for different 46
Setting of TSM in Zon 2, UTM
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LIST OF SYMBOLS
T - Torque
a - Angles of induction relays (side A) b - Angles of induction relays (side B) Ia - current of induction relays (side A)
Ib - current of induction relays (side B)
T - Time operating relay
M - Multiple of setting
TSM - Time Setting Multiplier
PSM - Plug Setting Multiplier
ROT - Relay Operating Time
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LIST OF APPENDICES
APPENDIX TITLE PAGE
A CAPTOR TCC Report for Single 57
Line Zon 1, UTM
B CAPTOR TCC Report for Single Line Zon 1, 65
UTM (Different setting of TSM)
C CAPTOR TCC Report for Single 69
Line Zon 2, UTM
D CAPTOR TCC Report for Single Line Zon 2, 79
UTM (Different setting of TSM)
E Example of Demand Load Report from 83
DAPPER function
F Example of Short Circuit Report from 84
DAPPER function
CHAPTER 1
INTRODUCTION
1.1 PROBLEM STATEMENT
Power system for must have a reliable and efficient protection scheme. Once
fault occurred on the system, it must be isolated as quickly as possible. This action could
minimize the effects on system stability and damage to plant. Referring to figure 1.1,
when a fault occurred on the system, one of the relay should be operated. However,
sometimes the relay that should be operated due to the fault does not work properly
delay in operation or does not function at all. It might be due to the problems from the
setting of the relay. Therefore, relay should be set properly to make it will function
accordingly. So, related to the problem, the study will be focused to the setting and
coordination of the relays that used in distribution system.
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Figure 1.1 Simple Circuits in Distribution System
1.2 OBJECTIVES
The main objective is to study how to setting the relay on the distribution
network, under various fault location. Secondly is to improve the reliability and
efficiency of power distribution by using optimum relay coordination. This project
focused on the application of relay in a power distribution system.
1.3 SCOPE OF WORK
Research will be focused on relay setting and coordination in power distribution
system. It involves in studying the characteristic of the relay, specification and function
of the relay in power distribution system. Then, analyze the different setting of relay and
the coordination using suitable software. For simulation, the single line diagram will be
used to analyze the real system in distribution. From the analysis, the setting and
11kV 250MVA
A B C
F
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coordination of relay in distribution system will be developed. Figure 1.2 shows the
Project Overview of this project.
Figure 1.2 Project Overview
Background
knowledge of fault, relay and
distribution network
Single line diagram from TNB
for simulation
Relay setting, coordination, and
characteristics
Analyze and compare the
simulation result to make conclusion
Repeat simulation with different setting and coordination of
relay
Computer simulation using suitable software
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1.4 ORGANIZATION OF THE THESIS
This thesis consists of five chapters. Each chapter will discuss the details about
the particular topic. First chapter covers the introduction of the project and scope of
work. This chapter highlights the overview of the project title and work flow of
methodology.
The second chapter describes the theory and technical literature. This topic
covered all the protection that used in distribution power system. The different types of
relay also discussed in this topic. This project focuses more on inverse definite minimum
times relay (IDMT) and the coordination concept in distribution system.
The software that used in setting and coordination of overcurrent relay was
present in the third chapter. Two main functions from SKM Power Tools software
namely, Distribution Analysis for Power Planning Evaluation and Reporting (DAPPER)
and Computer Aided Plotting for Time Overcurrent Reporting (CAPTOR) were
discussed in this chapter.
In the chapter four, presents the results of the study along with the discussions of
results. The result from simulation give the setting and coordination of overcurrent relay
in distribution system.
Finally, a conclusion and future recommendation of this project is present in
chapter five. Appendices sections are included to assist in further understanding on the
subject of this project.
CHAPTER 2
POWER SYSTEM PROTECTION
2.1 INTRODUCTION
Protection system for power system has been developed to minimize the damage
and to make sure supply in safe condition, continuously and economically. Relay is one
of the most important components in protection system. There is several kind of relay
that each kind has own characteristic. A relay is device that makes a measurement or
receives a signal that causes it to operate and to effect the operation of other equipment.
It responds abnormal conditions in faulty section of the system with the minimum
interruption of supply. The advantages of isolating a system fault as quickly as possible
include safety for personnel and public, minimizing damage to plant and minimizing
effects on system stability.
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2.2 PROTECTION FOR POWER DISTRIBUTION SYSTEM
The distribution system need a protection to minimize the damage and to ensure
supply is reliable and economically. Protection systems distinguish between the
protections against overload currents, effect of short circuit current and excessive
temperature rise. Protective system should provide reliability, selectivity, speed,
economy and stability in power system.
2.3 PROTECTION DEVICES
There are three-protection device used in distribution system:
1. Fuse
2. Circuit breaker
3. Relay
2.3.1 Fuse
The fuse is a preliminary protective device. As the power capacity and voltage of
electrical installations increase and their switching circuits become complicated, fuse
protection become inadequate. This leads to the development of protective gears based
on special, automatic device relays that are called protective relaying.
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2.3.2 Circuit breaker
A circuit breaker is a device that is not designed for frequent operation, but is
capable of making and breaking all currents including fault currents up to its relative
high rated breaking capacity. One great advantage of circuit breakers is their speedy
operation, comparatively speaking, on a small overloads and the considerable control of
operating time under these conditions.
2.3.3 Relay
Relays are used to respond to the various functions of the power system
quantities to protect against system hazards. A protection relay is devices that respond to
fault conditions and give a signal for circuit breaker to operate and isolate the fault.
2.4 RELAYS
A relay is a device that makes a measurement or receives a signal, which causes
it to operate and to effect the operation of other equipment. A protection relay is a device
that responds to abnormal conditions in an electrical power system to operate a circuit
breaker to disconnect the faulty section of the system with the minimum interruption of
supply. Many designs of relay elements have been produced but these are based on a
few basic operating principles. The great majority of electro-mechanical relays are in
one of the following groups:
1. Induction relays
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2. Attracted-armature relays
3. Moving-coil relays
4. Thermal relays
5. Timing relays
6. Static relays
2.4.1 Induction Relays
The induction relay is based on the domestic kilowatt-hour meter, which
has a metal disc free to rotate between the poles of two electromagnets. Torque is
produced by the interaction of upper electromagnet flux and eddy currents
induced in the disc by the lower electromagnet flux, and vice versa. The torque
produced is proportional to the product of upper and lower electromagnet fluxes
and the sine of the angle between them.
T a b sin A
This means that maximum torque is produced when the angles between
the fluxes are 90 and as are proportional to Ia and Ib T Ia Ib sin A. Torque applied to a disc without control would, of course, continually accelerate
the disc to a speed limited only by friction and windage. Control is provided in
two ways:
1. By a permanent magnet whose field passes through the disc and produces a
braking force proportional to disc speed. This controls the time characteristic
of the relay.
2. By a control spring which produces a torque proportional to disc angular
displacement. This controls disc speed at low values of torque and
determines the relay setting.
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Disc speed is dependent on torque and as disc travel over a fixed distance is
inversely proportional to time, an inverse time characteristic is produced. Figure
2.1 shows the basic operational of induction relays.
Typical applications:
a) Wattmetric relay
b) KVAr relay
c) Phase-angle-compensated relay
d) Overcurrent relay
e) Over/under voltage relay
Figure 2.1 Induction relays
2.4.2 Attracted-armature relays
The attracted-armature relay comprises an iron-cored electromagnet,
which attracts an armature, which is pivoted, hinged or otherwise supported to
permit motion in the magnetic field. The magnetic circuit can be presented in a
similar manner to an electric circuit, using magneto-motive force (m.m.f) in
ampere-turns applied to the reluctance of the iron and air gap in series-
represented by resistance-which causes a flux to flow in the circuit. The
permeability of the iron is much higher than that of air, which means that most of
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the mmf will be used to magnetise the air gap. When the relay starts to operate,
the length of the air gap, and therefore the reluctance, decreases which causes the
flux, and the force, to increase. The effect of this in practical terms is that when
the current in the coil reaches a value which produces sufficient force to move
the armature-movement of the armature itself causes the flux and the operating
forces to increase. So that once the armature moves it accelerates with increasing
force until it is fully closed. This is the reason that contactors are very successful
because once the contactor starts to move positive contact making is assured.
In d.c. operated relays residual flux is a problem and may prevent release
of the armature. In order to reduce it to alow value the armature should not bed
entirely on both poles of the electromagnet in the closed position but should
always have a non-magnetic stop, to ensure that there is a small air gap. In
general attracted-armature relays are used:
1. As auxiliary repeat relays and for flag indicators. These are
known as all-or-nothing relays.
2. As measuring relays where a drop-off/pick-up ratio of less than
90% can be tolerated.
Typical applications:
a) All-or-nothing relays
b) Measuring relays
2.4.3 Moving-coil relays
The moving coil relay consists of a light coil which when energized
moves in a strong permanent magnet field. The coil can either be pivoted
between bearings as in the usual moving-coil instrument or suspended in the
magnet field in the manner of the moving-coil. In both cases the movement very
sensitive that is very little energy is required to produce operating force. The
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forced produced is proportional to the product of the permanent magnet flux and
the coil current. The axial relay is less sensitive but is very robust. It has the
advantage of having no bearings but on the other hand is affected by gravity if
the relay case is not correctly aligned on the panel. In general moving-coil relays
are used:
1. Where a sensitive relay is required
2. To provide a high drop-off/pick up ratio
3. Where the relay can be subjected to a continuous overload of
many times its setting
4. In high-speed protection schemes.
2.4.4 Thermal relays
These are relays in which the operating quantity generates heat in a
resistance winding and so affects some temperature-sensitive component. Most
protective relays of the thermal type are based upon the expansion of metal, a
typical example being the use of bimetal material. Thermal relays are suitable for
use as overload relays where good accuracy and a long time delay are required.
2.4.5 Timing relays
In some circumstances a time delay is required in conjunction with
protection relays. These fall into three distinct groups:
1. Short-time relays
2. Medium-value accurate-time delays
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3. Long time relays
Design of the protective relays with certain certain principles as:
a) Simplicity
b) High operating force
c) High contact pressure
d) Contact circuit voltage
e) Contact-making action
f) Minimum size of wire
g) Enclosures
2.4.6 Static relays
At the outset, change from electromechanical relays to static relays was
very slow because of the relative costs. Since the cost of electronic relays
became less than the cost of equivalent electromechanical relays the transition
has been rapid and practically all-new installations are being equipped with
electronic types. The electromechanical relay will be with us for many years to
come and so are described not only for this reason but because the operation and
application of the electronic equivalents will be more easily understood.
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2.5 REQUIREMENTS
Main characteristics of protective relaying equipment are sensitivity,
selectivity, speed and reliability. Relaying equipment must be sufficiently
sensitive to operate reliably when required under the actual conditions that
produce a slight operating tendency. However, it should not operate in a wrong
manner. The ability of the protective relay system to operate so as to trip only the
minimum number of breakers directly controlling the defective part of the system
is called selectivity of the relaying system. A protective relay must operate at the
required speed and must be reliable. The speed at which relays and circuit
breakers operate has a direct bearing on the quality of service to the consumer,
stability of the system, and the amount of power that could be transmitted
without endangering the life and equipment. The use of protective relays should
be evaluated on the basis of its contribution to the best economy in service to
consumers.
2.6 PROTECTIVE RELAY APPLICATION IN ELECTRICAL NETWORK
1. Phase overcurrent relay
This relay is set to avoid operation on all of those normal conditions to which they may be subjected.
2. Ground overcurrent relays
This relay is advantage of utilizing a current source that supplies little or no normal current to the relays.
3. Directional overcurrent relays.
4. Phase overcurrent relays.
5. Ground overcurrent relays.
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2.7 PROTECTIVE RELAYING
Protective relaying is the basic form of electrical automatic equipment and is
indispensable for normal and dependable operation of modern power distribution
systems. When a fault occurs, the protection detects and disconnects the faulty section
from the system, acting on the circuit breakers for tripping. When an abnormal
condition, protection detects and depending on the nature of disturbance, performs the
necessary operations to restore the normal conditions or a tripping action to circuit
breaker.
2.7.1 Applications
Types There are two broad categories of protection; primary and backup. The
primary is the first line protection but some form of backup protection must be
provided. There are two such forms; local and remote. Local backup protection is
provided at the same location as the primary protection, whereas remote backup
protection as the name implies, is applied at another switching station. An
example of remote backup protection is the simple time graded relays as shown
in figure 2.2. A fault at F1 would normally be seen first by relay R1 and isolated
by the circuit breaker at R1. In the event of failure of the relay or associated
equipment at R1, the fault would be isolated by the operation of the relay R2.
Similarly, if a fault were at F2, in case the relay or allied equipment fails at R2,
the fault would be cleared by relay R3.
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Figure 2.2 Circuit of Time Graded Scheme
2.7.2 System
Successful application of protective gear involves thorough knowledge of
the system to be protected and the method of its operation. The maximum and
minimum fault levels for different types of faults occurring at different points of
the system must be calculated. The maximum load current must be known to
determine whether the ratio of the minimum fault current to maximum load
currents is high enough to enable simple overcurrent operated relays to be used
successfully.
R3 R2 R1
F2 F1
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2.7.3 Scheme
After the system details have been studied, a suitable protective scheme
can be chosen. The choice depends on following factors. The protective scheme
chosen will normally be supplied with samples of the system current and voltage
by means of current and voltage transformers.
The following are the common protection scheme used:
a) Time-graded overcurrent protection
This is based on the time/current principle of protection.
b) Distance protection
It serves the need for faster clearing times as the fault level increases and
also because of the difficulty in grading time/overcurrent relays with the
ever increasing number of switching stations creating more stage of
protection. Normally applied for feeder protection of 66,110 and 132kV
and above lines.
c) Differential protection
It consists of pilot wire protection and is quick acting. Generally applied
for transformers having capacity about 5-10MVA and above.
d) Restricted earth fault protection
Normally used for winding of the transformer connected in star, where
the neutral point is either solidly earthed or earthed through impedance.
The relay used is of high impedance type to make the scheme stable for
external faults.
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2.8 RELAY COORDINATION CONCEPT
2.8.1 Radial System
The specific protective relay as primary or backup is important in
distribution system. When relay applied to protect its own system element it is
thought of primary relay, when to backup other relays for fault at remote
location, it is serving as backup relay. Providing both functions simultaneously;
serving primary relay for its own zone protection and backup relay for remote
zone of protection. The protective relay must be time-coordinated, so that the
primary relay will always operate faster than the backup relay. So, the setting and
coordination of the relay is the very important part to make sure which relay
stands for primary and the other one for backup.
2.8.2 Ring System
To setting relay, the same method is used for both ring and radial system.
However, the circuit must be opened, start at the source point to form a two
radial circuit before setting the relay. First, followed the clockwise and system
will form the relay as 5-4-3-2-1 by referring figure 2.3. The relay setting start
with R1 and the concept same like radial system. Second, followed the anti-
clockwise and the system will form a radial circuit like e-d-c-b-a as shown
below. The relay setting start with Ra and the coordination concept same like
radial system. For time setting multiplier (TSM) value, set with minimum value
for primary relay and increased for backup relay.
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Figure 2.3 Relay coordination concepts for ring system
2.9 OVERCURRENT RELAY
2.9.1 Overcurrent Protection
The overcurrent relay is probably the most straightforward type of
protective relay. It monitors the current flowing in the phase conductor and
therefore its operating level must be set above the normal healthy level of current
in the circuit. It is important to realize that overcurrent relays are designed as
fault detecting devices and should not be thought of as overload devices.
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2.9.2 Overcurrent IDMT Type Relays
The overcurrent relay, which gives inverse definite minimum time
characteristics essentially, consists of an ac metre mechanism modified to give
the required characteristics. The upper electromagnet has two windings. One is
connected to the CT in line for the equipment to be protected and is tapped at
intervals. The tappings are connected to a plug setting bridge by which the
number of turns in use can be adjusted, thus giving the desired current setting.
The second winding is energized by induction from the primary and is connected
to the winding of the lower electromagnet. The disc spindle carries a moving
contact which bridges two fixed contacts when the disc has rotated through an
angle, which can be adjusted to give any desired time setting.
2.10 OVERCURRENT SCHEMES
2.10.1 Shortcomings
The inherent shortcomings of overcurrent schemes are:
a. Inability to distinguish between operating conditions at maximum
generation and fault conditions at minimum generation.
b. Comparatively large fault clearing time involved in clearing the
faults.
c. Increased settings at the generating ends in order to provide
suitable discrimination times between sections.
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2.10.2 Overcurrent Relay in a Distribution System
The application of overcurrent relays in a system is not simple and
requires a thorough checking of the other components for coordination within the
system for reliable protection. To ensuring proper protection in distribution
system, the following steps are involved. A single line diagram of the system is
drawn with various elements, such as bus bars, transformers, CTs ratio marked
so that a clear picture is obtained of the system. Information of the relays used
and all the settings must collect and recorded. Current settings are tentatively
decided next to allow maximum full load currents continuously.
2.11 TIME GRADED OVERCURRENT PROTECTION
The principle electromechanical relay used for this application is the
inverse-time relay that is an induction relay in which torque is proportional to I2.
This relay has a range of current settings, usually 50% to 200% of nominal
current in 25% steps. The setting is generally selected by the position of a plug in
a plug bridge, which determines the number of active turns on the operating coil
and therefore the current setting. The relay operating time can also be varied. At
the maximum time setting the disc has to travel through 180 before contact is made. By moving the disc reset position closer to the contact-making position the
operating time can be reduced. There is an adjuster, known as the multiplier,
with a calibrated scale of 0.1 to 1.0, which is used to set, the disc reset position.
The standard relay has a characteristic:
T = 3(logM)-1 or 3/ log M
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Where, M is the multiple of setting. This type of relay is known as the Inverse
Definite-Minimum Time (IDMT) relay.
2.11.1 Settings
When determining a setting for an IDMT relay a number of allowances
made by BS142 must be taken into account. BS142 states that the relay must
definitely operate at 130% setting. Modern electromechanical relays have a reset
figure of 90% and a operate figure of 110%. These affect the choice of plug
setting in two ways:
1. Under normal full-load conditions, the relay occupies the fully reset position
2. Plug setting should be chosen so that the overload current does not exceed
1.1 times the setting.
The current setting can be adjusted in 5% steps which allow a much closer
setting than that which is possible with the 25% steps associated with
electromechanical relays. If the relay which should operate first was given a
current setting higher than the following relay, at lower values of current
discrimination may result. Therefore the general rule is that the current setting of
a relay nearer the source must always be the same or higher than the setting of
the preceding relay.
2.11.2 Time-multiplier setting
There are four factors which affect the discrimination period between relays.
1. A variation from the ideal characteristic curve for which an error in time of
0.1s is used for calculation purposes.
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2. Overshoot, disc movement after the removal of current.
3. Circuit breaker operating time, 0.15s is allowed.
4. Contact gap. To ensure that a relay still has a short distance to travel when
the fault is cleared by the relay with which it is discriminating.
The minimum discrimination period of 0.4s is the time interval between relay
operations at the maximum fault level. Figure 2.4 shows the standard IDMT
current-time characteristic of different value Time Setting Multiplier. The
vertical axis of current-time graph is Time Setting multiplier and horizontal axis
is Plug Setting Multiplier.
Figure 2.4 Standard IDMT current-time characteristic
CHAPTER 3
SOFTWARE
3.1 INTRODUCTION
This project used SKM Power Tools for Windows for simulation part. Two
functions, Distribution Analysis for Power Planning Evaluation and Reporting
(DAPPER) and Computer Aided Plotting for Time Overcurrent Reporting (CAPTOR)
are used to setting and coordination of overcurrent relay. The simulation used real data
such as bus voltage, load demand, and nominal transformer rating, which are taken from
Universiti Teknologi Malaysia Distribution.
Figure 3.4 shows the single line diagram of UTM Distribution used in this
project. For simulation using SKM Power Tools, the whole system was dividing into 2
zones. This will make the coordination work easier and systematic.
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3.2 SKM Power Tools for Windows
SKM Power Tools for Windows is used to model and analyze power system and
coordinate protective relays. SKM Power Tools is electrical engineering analysis
software developed by SKM Systems Analysis. SKM also provides several analysis and
simulation with the functions of report and graph generating automatically. The several
purposes are:
1. Power Systems designing/modeling
2. Short circuit test and fault analysis
3. Load flow and demand load current analysis
4. Time current coordination for protection system
5. Harmonic analysis
6. Motor starting analysis
7. Transient stability simulation
Two main functions from SKM Power Tools will be used in the simulation, namely
Distribution Analysis for Power Planning Evaluation and Reporting (DAPPER) and
Computer Aided Plotting for Time Overcurrent Reporting (CAPTOR).
3.2.1 DAPPER (Distribution Analysis for Power Planning Evaluation and
Reporting)
This function is used to analyze and modeling power system with balance system
studies including load flow, demand load and power system fault. Start with modeling
the single line diagram and enter all the required data for the component that been used
in the system. After modeling, run the balance system and all the result will be listed
down in report function. Results will be used for other studies such as relay setting and
coordination.
25
Component editor
Component Editor is a dialog box that lets you easily add, edit, copy, and delete
system components in a convenient list format. Automatically generate one-line
diagrams from system data entered through the Component Editor. Equipment list
expands to show connections between system components allowing easy navigation.
Sort devices by type, or run queries to list equipment according to your own criteria such
as component type, voltage drop limits, voltage range, group association, etc. Figure 3.1
shows the component editor function used in SKM to modeling the single line power
system.
Figure 3.1 Component editor function
Libraries Save Time, Automate Data Entry, and Standardize Designs
User-definable libraries for cables, transformers, loads, motors and protective
devices ensure consistency and minimize data entry. Customize libraries to precisely
model equipment from the manufacturers published data. Switch libraries within a
single project to rapidly evaluate what if scenarios. Extensive default libraries can be
applied directly to any project. Advanced libraries for sub-transient level generator and
26
motor models, user-definable governors, exciters, power system stabilizers, frequency-
sensitive loads, protective devices, harmonic sources, reliability failure rates, DC
components, and transmission line configurations.
3.2.2 CAPTOR (Computer Aided Plotting for Time Overcurrent Reporting)
This function is used for coordination the protective devices. CAPTOR allows us
to change the setting for protective devices and plot the current-time graph
automatically. The current-time coordination report shows the information of device
setting, operating time and fault duty of the relay. Appendix A shows the example of
CAPTOR Report.
3.3 SKM in Relay Coordination
There are four major steps for setting and coordination of overcurrent relay in
distribution system in order to design good protection system.
1. Modeling
2. Simulation and analysis
3. Coordination
4. Evaluation
27
3.3.1 Modeling
Start with modeling the single line diagram based on real diagram. Select the
components in software library that categorized by function and specification. Based on
the real data of the component, components rating will be set in Component Editor.
3.3.2 Simulation and analysis
After modeling the system, run the model to get basic data such as fault current
and load flow. To run the system, select the balanced system studies function. The
output report will generate automatically for each studies for review. The examples of
balanced system study setup are demand load (dl.rpt), load flow (lf.rpt) and short circuit
(sc.rpt) shown in Appendix E and Appendix F.
3.3.3 Coordination
After running the balanced system studies, the simulations continue with
coordination part. In order to do that, data like fault current and demand load must be
obtained in advanced. To start the coordination, select the specific component in single
line diagram, and then press the right click mouse. Select the TCC drawing and as a
result, the current-time graph will be plotted together with component curve. The
voltage and fault current that applied to component are shown in component setting.
From the voltage and fault current data, the setting and coordination for overcurrent
relay can be done. The series rating must be filled with a value that larger than fault
current. Series rating is the value of current rating multiple with instantaneous value. So
that, the specified device can operates within the current range. The current transformer
28
ratio and relay setting can be found in setting section. The value of current transformer
ratio should be referring to demand load of that components, normally set higher than
demand current. Relay setting- (Tap, Standard Inverse, and Instantaneous) will make the
curve and operating time of relay change depend on that value. Adder/Shifter has to be
set to find out the operating time of protection devices. Figure 3.4 shows the relay adder,
shifter, and calibration points function. The value of adder/shifter should refer to
Instantaneous.
Figure 3.2 Relay adder, shifter, and calibration points function.
3.3.4 Evaluation
The TCC report includes the device setting, fault duty, voltage and operating
time. The report is generating automatically, choose the report function to see all the
report data. Coordination of protection devices can be evaluated by referring to TCC
report and checking the relay operating time. TCC also give the information about
functionality of protection system. There are four setting used in this report:
1. Time Setting Multiplier (TSM) is the Standard Inverse
29
2. Plug Setting Multiplier (PSM) is the Instantaneous
3. Relay Operating Time (ROT) is the Test Point in TCC report
4. RCOT is ROT/TSM
Figure 3.5 shows the example settings of IDMT overcurrent relay.
Figure 3.3 Setting of IDMT overcurrent relay
30
Figure 3.4 Single Line Diagram of UTM Power Distribution [7]
CHAPTER 4
RESULT AND DISCUSSION
4.1 Introduction
This chapter presents the simulation results of setting and coordination of
overcurrent relay in UTM distribution system. Start with modeling the single line using
DAPPER in SKM Power Tools and enter the real components rating. Then, run the
balanced system studies to get the data like load flow, short circuit current and demand
load. To setting and coordinate the overcurrent relays, used the CAPTOR TCC function
for each relay and the current-time graph will be plotted automatically. Finally, go to the
TCC report function to generate the CAPTOR TCC report that shown in Appendix A.
Figure 4.1 shows the single line diagram for Zon 1 that used in simulation part. For
simulation using SKM Power Tools, the whole system was dividing into 2 zones, Zon 1
and Zon 2. This will make the coordination work easier and systematic.
32
4.2 RESULT OF SIMULATION FOR ZON 1
Figure 4.1 Single line diagram of UTMs distribution for ZON 1 [7]
22kV
R7
R13
R1
R12
R2
R11
R15
R16
R14
R6
R8
R5
R27
R26
R9
R4
R3
R10 R22
R25 R23
R21
R20 R19
R18 R17
R24
PMU
33
Figure 4.2 shows the single line for Zon 1, UTM that modeling in DAPPER
functions. All the components rating must be correct to make sure the system working
properly.
Figure 4.3 shows the current-time graph for Zon1, UTM. From the graph, the
coordination of the relay will be obtained. For example, R21, R22 and R27 will be work
as primary relay because the curve was plotted at minimum operating time. But, R13
and R14 will be work as back-up relay because the curve was plotted at maximum
operating time.
Figure 4.4 shows the current-time graphs for different setting of TSM in Zon 1,
UTM. Compare the graph from figure 4.3; the curve of selected relay was plotted at
different operating time because the different setting of Time Setting Multiplier. Figure
4.4 shows when the TSM increased, the operating time of relay also increased.
34
Figure 4.2 Single line diagrams for Zon 1, UTM using SKM Power Tools [7]
35
Figure 4.3 Current-time graphs for Zon 1, UTM
36
Figure 4.4 Current-time graphs for different setting of TSM in Zon 1, UTM
37
4.2.1 Result for overcurrent relay setting in Zon 1, UTM
Table 4.1 shows the setting of overcurrent relay in Zon 1, UTM. A relay setting
like PSM, TSM, ROT and RCOT was shown in this table. The different value of Relay
Operating Time (ROT) depends on the setting of Plug Setting Multiplier (PSM) and
Time Setting Multiplier (TSM). For example, the setting of PSM for relay R1 is 18 and
setting of TSM is 0.1. Then, the relay will take 0.235s to send the signal to circuit
breaker to operate. This time is called as Relay Operating Time (ROT).
Table 4.1 Setting of overcurrent relay in Zon 1, UTM
Relay Setting Result
R1 PSM
RCOT
TSM
ROT
18
2.35
0.1
0.235s
R2 PSM
RCOT
TSM
ROT
18
2.355
0.2
0.471s
R3 PSM
RCOT
TSM
ROT
18
2.353
0.3
0.706s
R4 PSM
RCOT
TSM
ROT
18
2.353
0.4
0.941s
38
R5 PSM
RCOT
TSM
ROT
18
2.353
0.45
1.059s
R6 PSM
RCOT
TSM
ROT
11
2.85
0.5
1.425s
R7 PSM
RCOT
TSM
ROT
11
2.85
0.6
1.710s
R8 PSM
RCOT
TSM
ROT
18
2.35
0.1
0.235s
R9 PSM
RCOT
TSM
ROT
18
2.355
0.2
0.471s
R10 PSM
RCOT
TSM
ROT
18
2.353
0.3
0.706s
R11 PSM
RCOT
TSM
ROT
18
2.353
0.4
0.941s
R12 PSM
RCOT
TSM
18
2.353
0.45
39
ROT 1.059s
R13 PSM
RCOT
TSM
ROT
11
2.85
0.5
1.425s
R14 PSM
RCOT
TSM
ROT
11
2.85
0.6
1.710s
R15 PSM
RCOT
TSM
ROT
18
2.352
0.25
0.588s
R16 PSM
RCOT
TSM
ROT
18
2.353
0.3
0.706s
40
4.2.2 Different setting of Time Setting Multiplier (TSM) in Zon 1, UTM
Meanwhile, results for different setting of overcurrent relay in Zon 1 are shown
in Table 4.2. A relay setting like PSM, TSM, ROT and RCOT was shown in this table.
The different value of Relay Operating Time (ROT) depends on the setting of Plug
Setting Multiplier (PSM) and Time Setting Multiplier (TSM). Different setting of Time
Setting Multiplier was conduct to see the relation between Time Setting Multiplier and
Relay Operating Time. From the result, when the TSM value is minimum (0.1), the
operating time of relay will be the minimum value. That means, the operating time of
relay depends on the setting of TSM value. For example, the setting of PSM for relay
R27 is 27 and setting of TSM is 0.1. Then, the relay will take 0.205s to send the signal to
circuit breaker to operate. This time is called as Relay Operating Time (ROT). But,
when the TSM is 0.5 the relay will take 1.027s to send the signal to circuit breaker.
Table 4.2 Setting of overcurrent relay in Zon 1, UTM (different setting of TSM)
Relay Setting Result 1 Result 2
R17 PSM
RCOT
TSM
ROT
30
1.99
0.1
0.199s
30
1.988
0.5
0.994s
R18 PSM
RCOT
TSM
ROT
30
1.99
0.1
0.199s
30
1.988
0.5
0.994s
R19 PSM
RCOT
TSM
ROT
30
1.99
0.1
0.199s
30
1.988
0.5
0.994s
R20 PSM 30 30
41
RCOT
TSM
ROT
1.99
0.1
0.199s
1.988
0.5
0.994s
R21 PSM
RCOT
TSM
ROT
27
2.05
0.2
0.205s
27
2.054
0.5
1.027s
R22 PSM
RCOT
TSM
ROT
27
2.05
0.1
0.205s
27
2.054
0.5
1.027s
R23 PSM
RCOT
TSM
ROT
30
1.99
0.1
0.199s
30
1.988
0.5
0.994s
R24 PSM
RCOT
TSM
ROT
30
1.99
0.1
0.199s
30
1.988
0.5
0.994s
R25 PSM
RCOT
TSM
ROT
30
1.99
0.1
0.199s
30
1.988
0.5
0.994s
R26 PSM
RCOT
TSM
ROT
27
2.05
0.1
0.205s
27
2.054
0.5
1.027s
R27 PSM
RCOT
TSM
ROT
27
2.05
0.1
0.205s
27
2.054
0.5
1.027s
42
4.3 RESULT OF SIMULATION FOR ZON 2
Figure 4.5 Single line diagram of UTMs distribution for ZON 2 [7]
22kV
R1
R2
R10
R9
R8
R7
R6
R5
R11
R4
R3
R24 R23
R22
R21
R20
R19
R18
R17
R16
R15
R14
R13
R12
R35
R33 R32
R31
R29
R28
R27
R26 R25
R34
PMU
R30
43
Figure 4.6 shows the single line for Zon 2, UTM that modeling in DAPPER
functions. All the components rating must be correct to make sure the system working
properly.
Figure 4.7 shows the current-time graph for Zon 2, UTM. From the graph, the
coordination of the relay will be obtained. For example, R27, R28 and R29 will be work
as primary relay because the curve was plotted at minimum operating time. But, R10
and R11 will be work as back-up relay because the curve was plotted at maximum
operating time.
Figure 4.8 shows the current-time graphs for different setting of TSM in Zon 2,
UTM. Compare the graph from figure 4.7; the curve of selected relay was plotted at
different operating time because the different setting of Time Setting Multiplier. Figure
4.8 shows when the TSM increased, the operating time of relay also increased.
44
Figure 4.6 Single line diagrams for Zon 2, UTM using SKM Power Tools [7]
45
Figure 4.7 Current-time graphs for Zon 2, UTM
46
Figure 4.8 Current-time graphs for different setting of TSM in Zon 2, UTM
47
4.3.1 Result for overcurrent relay setting in Zon 2, UTM
Table 4.3 shows the setting of overcurrent relay in Zon 2, UTM. A relay setting
like PSM, TSM, ROT and RCOT was shown in this table. The different value of Relay
Operating Time (ROT) depends on the setting of Plug Setting Multiplier (PSM) and
Time Setting Multiplier (TSM). For example, the setting of PSM for relay R22 is 11 and
setting of TSM is 0.9. Then, the relay will take 2.565s to send the signal to circuit
breaker to operate. This time is called as Relay Operating Time (ROT).
Table 4.3 Setting of overcurrent relay in Zon 2, UTM
Relay Setting Result
R1 PSM
RCOT
TSM
ROT
11
2.85
0.1
0.285s
R2 PSM
RCOT
TSM
ROT
11
2.85
0.2
0.570s
R3 PSM
RCOT
TSM
ROT
11
2.85
0.3
0.855s
R4 PSM
RCOT
TSM
ROT
11
2.849
0.35
0.997s
R5 PSM
RCOT
11
2.85
48
TSM
ROT
0.4
1.140s
R6 PSM
RCOT
TSM
ROT
11
2.849
0.45
1.282s
R7 PSM
RCOT
TSM
ROT
11
2.85
0.5
1.425s
R8 PSM
RCOT
TSM
ROT
11
2.85
0.6
1.710s
R9 PSM
RCOT
TSM
ROT
11
2.85
0.7
1.995s
R10 PSM
RCOT
TSM
ROT
11
2.85
0.8
2.820s
R11 PSM
RCOT
TSM
ROT
11
2.85
0.9
2.565s
R12 PSM
RCOT
TSM
ROT
11
2.85
0.1
0.285s
R13 PSM 11
49
RCOT
TSM
ROT
2.85
0.2
0.570s
R14 PSM
RCOT
TSM
ROT
11
2.85
0.3
0.855s
R15 PSM
RCOT
TSM
ROT
11
2.849
0.35
0.997s
R16 PSM
RCOT
TSM
ROT
11
2.85
0.4
1.140s
R17 PSM
RCOT
TSM
ROT
11
2.849
0.45
1.282s
R18 PSM
RCOT
TSM
ROT
11
2.85
0.5
1.425s
R19 PSM
RCOT
TSM
ROT
11
2.85
0.6
1.710s
R20 PSM
RCOT
TSM
ROT
11
2.85
0.7
1.995s
50
R21 PSM
RCOT
TSM
ROT
11
2.85
0.8
2.280s
R22 PSM
RCOT
TSM
ROT
11
2.85
0.9
2.565s
4.3.2 Different setting of Time Setting Multiplier (TSM) in Zon 2, UTM
Table 4.4 shows the different setting of overcurrent relay in Zon 2, UTM. A relay
setting like PSM, TSM, ROT and RCOT are shown in this table. The different value of
Relay Operating Time (ROT) depends on the setting of Plug Setting Multiplier (PSM)
and Time Setting Multiplier (TSM). Different setting of Time Setting Multiplier was
conduct to see the relation between Time Setting Multiplier and Relay Operating Time.
From the result, when the TSM value is minimum (0.1), the operating time of relay will
be the minimum value. That means, the operating time of relay depends on the setting of
TSM value. For example, the setting of PSM for relay R35 is 25 and setting of TSM is
0.1. Then, the relay will take 0.211s to send the signal to circuit breaker to operate. This
time is called as Relay Operating Time (ROT). But, when the TSM is 0.5 the relay will
take 1.053s to send the signal to circuit breaker.
51
Table 4.4 Setting of overcurrent relay in Zon 2, UTM (different setting of TSM)
Relay Setting Result 1 Result 2
R23 PSM
RCOT
TSM
ROT
15
2.52
0.1
0.252s
15
2.515
0.4
1.006s
R24 PSM
RCOT
TSM
ROT
15
2.52
0.1
0.252s
15
2.515
0.4
1.006s
R25 PSM
RCOT
TSM
ROT
18
2.35
0.1
0.235s
18
2.353
0.3
0.706s
R26 PSM
RCOT
TSM
ROT
18
2.35
0.1
0.235s
18
2.353
0.3
0.706s
R27 PSM
RCOT
TSM
ROT
25
2.11
0.1
0.211s
25
2.106
0.5
1.053s
R28 PSM
RCOT
TSM
ROT
16
2.46
0.1
0.246s
16
2.456
0.5
1.228s
R29 PSM
RCOT
TSM
25
2.11
0.1
25
2.104
0.25
52
ROT 0.211s 0.526s
R30 PSM
RCOT
TSM
ROT
16
2.46
0.1
0.246s
16
2.456
0.25
0.614s
R31 PSM
RCOT
TSM
ROT
25
2.11
0.1
0.211s
25
2.105
0.4
0.842s
R32 PSM
RCOT
TSM
ROT
19
2.31
0.1
0.231s
19
2.307
0.3
0.692s
R33 PSM
RCOT
TSM
ROT
19
2.31
0.1
0.231s
19
2.308
0.5
1.154s
R34 PSM
RCOT
TSM
ROT
25
2.11
0.1
0.211s
25
2.104
0.45
0.947s
R35 PSM
RCOT
TSM
ROT
25
2.11
0.1
0.211s
25
2.106
0.5
1.053s
53
4.3 DISCUSSION
Based on the result, it is observed that the Time Setting Multiplier (TSM) was set
to 0.1 for primary relay and the delay time for backup relay is 0.5s. The setting of relay
can be adjusted from the TCC graph in order to determine the right setting and
coordination. For relay setting, Tap will set the starting operate time for relay and it will
move the curve vertically. Standard inverse will influence the real operating time (ROT)
as it is the time setting multiplier. The standard inverse also will move the curve
vertically in the current-time graph. Instantaneous is plug setting multiplier (PSM) it will
control the operating range of relay and can extend the curve in TCC graph. For the different setting of TSM, the lower value of TSM will make the relay work as primary
relay. Appendix A, Appendix B, Appendix C, and Appendix D shows CAPTOR TCC
report for single line diagram in UTMs distribution. The setting value of overcurrent
relay such as Plug Setting Multiplier, Time Setting Multiplier, Tap, and Current Rating
will be checked by referring this CAPTOR Report.
Overcurrent relays are added to protect the system and relay coordination can be
done. For a huge system, separate the whole system to several zones according to bus
voltage. This will make the setting and coordination work much easier and systematic.
CHAPTER 5
CONCLUSION AND RECOMMENDATION
5.1 CONCLUSION
For the conclusion, the main objective to setting and coordinate the overcurrent
relay types IDMT for power distribution system are obtained. The setting and
coordination of relay has been done for radial and ring system. The current-time graph
for each relays that used in distribution system was automatically plotted by CAPTOR
TCC function. The Relay Operating Time depends on the setting of PSM and TSM
value. The effect of increasing Time Setting Multiplier is to increase the Relay
Operating Time.
55
5.2 RECOMMENDATIONS
There are some recommendations for further study in this topic:
1. Used different types of relays such as directional overcurrent relay, earth
fault protection and others. Some distribution system used different types of
relay like earth fault relay and directional overcurrent relay. The different
types of relay can be used to compare the operating time at different setting
of relays.
2. Combined all the protection system for distribution system and transmission
system. For transmission system, the protection that applied was different
with distribution system. So, if distribution and transmission system was
combined, we should get the different setting and coordination according to
the system.
56
REFERENCES
[1] Mohd Zin, A.A., Kejuruteraan Sistem Kuasa, Edisi Kedua, UTM, 2007
[2] Davies, T., Protection of Industrial Power Systems, Second Edition, Newnes,
1996
[3] Alberto J.Urdaneta, Luis G. Perez (1999), Optimal Coordination of Directional
Overcurrent Relay considering Definite Time Backup Relaying, Venezuela:
Universidad Simon Bolivar.
[4] Pabla, A. S., Electic Power Distribution, McGraw-Hill, 2005
[5] A.R. Van C. Warrington, Protective Relays: Theory and Practice, Chapman and
Hall Ltd., 1968.
[6] SKM Power Tools for Windows Manual & www.skm.com
[7] Single Line Diagram of 22kV Distribution Substation UTM, Pejabat Harta Bina
UTM Skudai, 2007.
[8] Ravindranath, B. and Chander, M., Power System Protection and Switchgear,
John Wiley & Sons, 1987
57
APPENDIX A
CAPTOR TCC Report for Single Line Zon 1, UTM
----------------------------------------------------------------------------------------- Apr 15, 2008 15:11:08 Page 1 Project Name: zon1 TCC Name: latest.tcc Reference Voltage: 22000 V Current Scale: X 10^0 TCC Notes: TCC Comment: Fault Duty Option: Study Result - Bus Fault Current ----------------------------------------------------------------------------------------- ALL INFORMATION PRESENTED IS FOR REVIEW, APPROVAL, INTERPRETATION, AND APPLICATION BY A REGISTERED ENGINEER ONLY. SKM DISCLAIMS ANY RESPONSIBILITY AND LIABILITY RESULTING FROM THE USE AND INTERPRETATION OF THIS SOFTWARE. ----------------------------------------------------------------------------------------- CAPTOR (Computer Aided Plotting for Time Overcurrent Reporting) COPYRIGHT SKM SYSTEMS ANALYSIS, INC. 1983-2006 ----------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------- Device Name: R-7 TCC Name: latest.tcc Bus Name: BUS-1 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5248.6A Current Rating: 500A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (500A) Test Points: @11.0X, 1.710s 2) [S] Standard Inverse 0.6 @8.0X, 1.978s 3) INST 11 (5500A) @5.0X, 2.568s ----------------------------------------------------------------------------------------- Device Name: R-13 TCC Name: latest.tcc Bus Name: PE02 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5239.1A Current Rating: 500A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (500A) Test Points: @11.0X, 1.425s 2) [S] Standard Inverse 0.5 @5.0X, 2.140s 3) INST 11 (5500A) @2.0X, 5.015s
58
----------------------------------------------------------------------------------------- Device Name: R-17 TCC Name: latest.tcc Bus Name: BUS-3 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 29658.6A Current Rating: 1000A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (1000A) Test Points: @30.0X, 0.199s 2) [S] Standard Inverse 0.1 @20.0X, 0.227s 3) INST 30 (30000A) @10.0X, 0.297s ----------------------------------------------------------------------------------------- Device Name: R-18 TCC Name: latest.tcc Bus Name: BUS-3 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 29658.6A Current Rating: 1000A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (1000A) Test Points: @30.0X, 0.199s 2) [S] Standard Inverse 0.1 @20.0X, 0.227s 3) INST 30 (30000A) @10.0X, 0.297s ----------------------------------------------------------------------------------------- Device Name: R-1 TCC Name: latest.tcc Bus Name: PE02 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5239.1A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.235s 2) [S] Standard Inverse 0.1 @15.0X, 0.252s 3) INST 18 (5400A) @10.0X, 0.297s ----------------------------------------------------------------------------------------- Device Name: R-12 TCC Name: latest.tcc Bus Name: PE03 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5228.9A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 1.059s 2) [S] Standard Inverse 0.45 @15.0X, 1.132s 3) INST 18 (5400A) @10.0X, 1.337s
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----------------------------------------------------------------------------------------- Device Name: R-15 TCC Name: latest.tcc Bus Name: PE03 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5228.9A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.588s 2) [S] Standard Inverse 0.25 @5.0X, 1.070s 3) INST 18 (5400A) @2.0X, 2.507s ----------------------------------------------------------------------------------------- Device Name: R-16 TCC Name: latest.tcc Bus Name: PE17 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5217.8A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.706s 2) [S] Standard Inverse 0.3 @15.0X, 0.755s 3) INST 18 (5400A) @10.0X, 0.891s ----------------------------------------------------------------------------------------- Device Name: R-19 TCC Name: latest.tcc Bus Name: BUS-15 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 29643.9A Current Rating: 1000A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (1000A) Test Points: @30.0X, 0.199s 2) [S] Standard Inverse 0.1 @20.0X, 0.227s 3) INST 30 (30000A) @10.0X, 0.297s ----------------------------------------------------------------------------------------- Device Name: R-20 TCC Name: latest.tcc Bus Name: BUS-15 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 29643.9A Current Rating: 1000A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (1000A) Test Points: @30.0X, 0.199s 2) [S] Standard Inverse 0.1 @20.0X, 0.227s 3) INST 30 (30000A) @10.0X, 0.297s
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----------------------------------------------------------------------------------------- Device Name: R-21 TCC Name: latest.tcc Bus Name: BUS-5 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 8085.0A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @27.0X, 0.205s 2) [S] Standard Inverse 0.1 @15.0X, 0.252s 3) INST 27 (8100A) @10.0X, 0.297s ----------------------------------------------------------------------------------------- Device Name: R-2 TCC Name: latest.tcc Bus Name: PE03 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5228.9A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.471s 2) [S] Standard Inverse 0.2 @15.0X, 0.503s 3) INST 18 (5400A) @10.0X, 0.594s ----------------------------------------------------------------------------------------- Device Name: R-11 TCC Name: latest.tcc Bus Name: PE04 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5223.6A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.941s 2) [S] Standard Inverse 0.4 @10.0X, 1.188s 3) INST 18 (5400A) @2.0X, 4.012s ----------------------------------------------------------------------------------------- Device Name: R-22 TCC Name: latest.tcc Bus Name: BUS-7 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 8084.7A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @25.0X, 0.211s 2) [S] Standard Inverse 0.1 @15.0X, 0.252s 3) INST 27 (8100A) @10.0X, 0.297s
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----------------------------------------------------------------------------------------- Device Name: R-3 TCC Name: latest.tcc Bus Name: PE04 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5223.6A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.706s 2) [S] Standard Inverse 0.3 @10.0X, 0.891s 3) INST 18 (5400A) @5.0X, 1.284s ----------------------------------------------------------------------------------------- Device Name: R-10 TCC Name: latest.tcc Bus Name: PE05 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5223.6A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.706s 2) [S] Standard Inverse 0.3 @15.0X, 0.755s 3) INST 18 (5400A) @10.0X, 0.891s ----------------------------------------------------------------------------------------- Device Name: R-23 TCC Name: latest.tcc Bus Name: BUS-9 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 29648.1A Current Rating: 1000A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (1000A) Test Points: @30.0X, 0.199s 2) [S] Standard Inverse 0.1 @20.0X, 0.227s 3) INST 30 (30000A) @10.0X, 0.297s ----------------------------------------------------------------------------------------- Device Name: R-24 TCC Name: latest.tcc Bus Name: BUS-9 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 29648.1A Current Rating: 1000A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (1000A) Test Points: @30.0X, 0.199s 2) [S] Standard Inverse 0.1 @20.0X, 0.227s 3) INST 30 (30000A) @10.0X, 0.297s
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----------------------------------------------------------------------------------------- Device Name: R-25 TCC Name: latest.tcc Bus Name: BUS-9 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 29648.1A Current Rating: 1000A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (1000A) Test Points: @30.0X, 0.199s 2) [S] Standard Inverse 0.1 @20.0X, 0.227s 3) INST 30 (30000A) @10.0X, 0.297s ----------------------------------------------------------------------------------------- Device Name: R-4 TCC Name: latest.tcc Bus Name: PE05 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5223.6A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.941s 2) [S] Standard Inverse 0.4 @15.0X, 1.006s 3) INST 18 (5400A) @10.0X, 1.188s ----------------------------------------------------------------------------------------- Device Name: R-9 TCC Name: latest.tcc Bus Name: PE06 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5228.9A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.471s 2) [S] Standard Inverse 0.2 @15.0X, 0.503s 3) INST 18 (5400A) @10.0X, 0.594s ----------------------------------------------------------------------------------------- Device Name: R-26 TCC Name: latest.tcc Bus Name: BUS-11 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 15693.2A Current Rating: 600A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (600A) Test Points: @27.0X, 0.205s 2) [S] Standard Inverse 0.1 @15.0X, 0.252s 3) INST 27 (16200A) @10.0X, 0.297s
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----------------------------------------------------------------------------------------- Device Name: R-5 TCC Name: latest.tcc Bus Name: PE06 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5228.9A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 1.059s 2) [S] Standard Inverse 0.45 @15.0X, 1.132s 3) INST 18 (5400A) @10.0X, 1.337s ----------------------------------------------------------------------------------------- Device Name: R-8 TCC Name: latest.tcc Bus Name: PE07 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5235.1A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @18.0X, 0.235s 2) [S] Standard Inverse 0.1 @15.0X, 0.252s 3) INST 18 (5400A) @10.0X, 0.297s ----------------------------------------------------------------------------------------- Device Name: R-27 TCC Name: latest.tcc Bus Name: BUS-13 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 8085.3A Current Rating: 300A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (300A) Test Points: @27.0X, 0.205s 2) [S] Standard Inverse 0.1 @15.0X, 0.252s 3) INST 27 (8100A) @10.0X, 0.297s ----------------------------------------------------------------------------------------- Device Name: R-6 TCC Name: latest.tcc Bus Name: PE07 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5235.1A Current Rating: 500A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (500A) Test Points: @11.0X, 1.425s 2) [S] Standard Inverse 0.5 @5.0X, 2.140s 3) INST 11 (5500A) @2.0X, 5.015s
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----------------------------------------------------------------------------------------- Device Name: R-14 TCC Name: latest.tcc Bus Name: BUS-1 Bus Voltage: 22000.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 5248.6A Current Rating: 500A / 5A Curve Multiplier: 1 Setting: 1) Tap, Is 1 (500A) Test Points: @11.0X, 1.710s 2) [S] Standard Inverse 0.6 @5.0X, 2.568s 3) INST 11 (5500A) @2.0X, 6.017s
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APPENDIX B
CAPTOR TCC Report for Single Line Zon 1, UTM (Different setting of TSM)
---------------------------------------------------------------------------------------- Apr 15, 2008 15:36:19 Page 1 Project Name: zon1 TCC Name: diffsetting.tcc Reference Voltage: 433 V Current Scale: X 10^0 TCC Notes: TCC Comment: Fault Duty Option: Study Result - Bus Fault Current ----------------------------------------------------------------------------------------- ALL INFORMATION PRESENTED IS FOR REVIEW, APPROVAL, INTERPRETATION, AND APPLICATION BY A REGISTERED ENGINEER ONLY. SKM DISCLAIMS ANY RESPONSIBILITY AND LIABILITY RESULTING FROM THE USE AND INTERPRETATION OF THIS SOFTWARE. ----------------------------------------------------------------------------------------- CAPTOR (Computer Aided Plotting for Time Overcurrent Reporting) COPYRIGHT SKM SYSTEMS ANALYSIS, INC. 1983-2006 ----------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------- Device Name: R-17 TCC Name: diffsetting.tcc Bus Name: BUS-3 Bus Voltage: 433.0V Function Name: Phase Manufacturer: GEC Description: In=5A Sub Type: MCGG 22, 42, 52, 53, 62, 63, 82 Class Description:MCGG AIC Rating: N/A Fault Duty: 29658.6A Current Rating: 1000A / 5A