This chapter introduces the project, which is to create an advanced user guide for the ETAP software to analyze power system protection designs. The guide will explain how to create a one-line diagram, configure protection equipment, perform fault and short circuit analysis. The objectives are to help engineers learn and apply ETAP, while the constraints include completing all tasks by the deadline and within budget.

1. PROTECTIVE DEVICE
COORDINATION
Héctor Rivera

2. POYTECHNIC UNIVERSITY OF PUERTO RICO
ELECTRICAL ENGINEERING DEPARTMENT
HATO REY, PUERTO RICO
PROTECTIVE DEVICE COORDINATION
GROUP 28
Rivera, Héctor J.
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3. Table of Contents
Table of Pictures ............................................................................................................................. 5
Chapter 1: General Information ...................................................................................................... 8
1.1 Abstracto ..................................................................................................................... 10
1.2 Abstract ....................................................................................................................... 11
1.3 Introduction ................................................................................................................. 12
1.4 Objectives ................................................................................................................... 14
1.5 Constraints .................................................................................................................. 15
Chapter 2: ETAP User Guide ....................................................................................................... 16
2.1 Basic ETAP User Guide ............................................................................................. 18
2.1.1 Creating a new ETAP Project. ............................................................................. 22
2.1.2 Opening an ETAP existing Project. ..................................................................... 23
2.1.3 Building New one-line Diagrams. ....................................................................... 25
2.1.4 Connecting Elements. .......................................................................................... 28
2.1.5 Adding a Protective Device to your One-Line. ................................................... 28
2.1.6 Verify if the element is connected. ...................................................................... 29
2.2 Advance ETAP User Guide ........................................................................................ 30
2.2.1 How to configure the elements in the one-line diagram. ..................................... 34
A) Utility ................................................................................................................. 34
B) High Voltage Circuit Breakers ........................................................................ 36
C) Low Voltage Circuits Breakers ....................................................................... 39
D) Protective Relay ................................................................................................ 44
E) Fuses Ratings .................................................................................................... 49
F) Transformer Properties: .................................................................................. 54
G) Load Properties: ............................................................................................... 57
H) Bus ...................................................................................................................... 58
2.2.2 Perform a Fault Analysis; .................................................................................... 59
Chapter 3: Transformer Case Study.............................................................................................. 61
3.1 Diagrams ..................................................................................................................... 64
3.2 Equipment Data .......................................................................................................... 66
3.3 Calculations ................................................................................................................ 68
3.4 Coordination Using ETAP Program ........................................................................... 73
3.5 Fault Simulation .......................................................................................................... 77
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4. 3.6 Settings and Results .................................................................................................... 81
Chapter 4: Bayamón WWTP Coordination Study........................................................................ 84
4.1 Scope ........................................................................................................................... 88
4.2 Electrical System Oneline Diagram ............................................................................ 90
4.3 Imput Data Report ...................................................................................................... 94
4.4 Calculations ................................................................................................................ 97
4.5 Short Circuit Study ................................................................................................... 138
4.6 Power Fuses Selection for Power Transformers T1, T2, T3, T4, T5, T6 and T7 ..... 160
4.7 Protection Relay Settings for ................................................................................. 173
Distribution Feeders ..................................................................................................... 173
4.8 Relay Settings ........................................................................................................... 178
4.9 Results ....................................................................................................................... 181
Chapter 5: Protective Device Coordination Project Results ....................................................... 186
5.1 Alternatives Considered ............................................................................................ 188
5.2 System Specifications ............................................................................................... 191
Operation .................................................................................................................... 193
Protective relay ........................................................................................................... 193
Distance relay ............................................................................................................ 195
Magazine Article............................................................................................................. 197
5.4 Budget ....................................................................................................................... 198
5.5 Bibliography ............................................................................................................. 199
5.6 Conclusion ................................................................................................................ 201
Chapter 6: Administrative Section .............................................................................................. 202
6.1 Protective Device Coordination Project Proposal..................................................... 205
Work Schedule ............................................................................................................ 217
Progress Report ............................................................................................................... 222
Work Schedule ................................................................................................................ 241
Appendix ..................................................................................................................................... 246
Tables and Curves ........................................................................................................... 247
Protection Relay Settings for Generators ........................................................................ 252
A.3 General Information ................................................................................................. 255
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5. Table of Pictures
Fig. 2.1: Create New Project Panel.................................................................................................... 22
Fig. 2.2: User Information Panel ....................................................................................................... 22
Fig. 2.3: Starting up window ............................................................................................................. 23
Fig. 2.4: Open Panel .......................................................................................................................... 24
Fig. 2.5: Selecting Project.................................................................................................................. 24
Fig. 2.6: Mode Toolbar ...................................................................................................................... 25
Fig.2.7: ETAP Elements .................................................................................................................... 27
Fig. 2.8: Connecting Elements .......................................................................................................... 28
Fig. 2.9: Open Panel .......................................................................................................................... 28
Fig. 2.10: Elements not connected..................................................................................................... 29
Fig. 2.11: Power Grid Editor Window .............................................................................................. 34
Fig. 2.12: High Voltage Circuit Breaker Editor Window .................................................................. 36
Fig. 2.13: Circuit Breaker Library ..................................................................................................... 37
Fig. 2.14: Low Voltage Circuit Breaker Window ............................................................................. 39
Fig. 2.15: Low Voltage Circuit Breaker library ................................................................................ 41
Fig. 2.16: Overcurent Relay Editor Window ..................................................................................... 44
Fig. 2.17: Overcurrent Settings Panel ................................................................................................ 45
Fig. 2.18: Instantaneus Settings Panel ............................................................................................... 46
Fig. 2.19: Fuse Editor Window ......................................................................................................... 49
Fig. 2.20: Fuse Library Window ....................................................................................................... 51
Fig. 2.21: Winding Transformer Editor Window .............................................................................. 54
Fig. 2.22: Transformer Rating Editor Window ................................................................................. 55
Fig. 2.23: Transformer Tap Editor Window ...................................................................................... 56
Fig. 2.24: Lumped Load Editor Window........................................................................................... 57
Fig. 2.25: Bus Editor Window ........................................................................................................... 58
Fig. 2.26: Fault Simulation ................................................................................................................ 59
Fig. 2.27: Select Sequence Viewer to find fault analysis results ....................................................... 60
Fig. 2.28: Results Window ................................................................................................................ 60
Fig. 3.1: Transformer Protection Diagram……………………………………………………....... 65
Fig. 3.2: Selected Fuse…………………………………………………………………………….. 67
Fig. 3.3: Selected Relay…………………………………………………………………………… 67
Fig. 3.4: Table of Current Transformer Specifications…………………………………………… 67
Fig. 3.5: Table of Power Fuse Rating……………………………………………………………... 71
Fig. 3.6: Overcurrent Relay Settings at Transformer……………………………………………... 74
Fig. 3.7: Overcurrent Relay Settings at Load 1,2…………………………………………………. 75
Fig. 3.8: Fuse Settings…………………………………………………………………………….. 76
Fig. 3.9: ETAP Simulation of Fault at Bus 1……………………………………………………… 78
Fig. 3.10: Sequence of Operation Events at Bus 1………………………………………………... 78
Fig. 3.11: ETAP Fault Simulation at Bus 2……………………………………………………….. 79
Fig. 3.12: Sequence of Operation Events at Bus 2………………………………………………... 79
Fig. 3.13: ETAP Fault Simulation at Load 1……………………………………………………… 80
Fig. 3.14: Sequence of Operation Events at Load 1………………………………………………. 80
Fig. 3.15: Relay and Fuse Settings………………………………………………………………... 83
Fig. 3.16: Results of Short Circuit Analysis………………………………………………………. 83
Fig. 4.1: Power Transformer Characteristics Table……………………………………………….. 89
Fig. 4.2: Generator Characteristics Table…………………………………………………………. 89
Fig. 4.3: Original Oneline Diagram of Bayamón WWTP………………………………………… 92
Fig. 4.4: Suggested Oneline Diagram of Bayamón WWTP………………………………………. 93
Fig. 4.5: Lines Cables……………………………………………………………………………... 95
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6. Fig. 4.6: Existing Transformer Line Cable. …………………………………………………….... 95
Fig. 4.7: Generator Cables………………………………………………………………………… 95
Fig. 4.8: Positive Sequence impedance Diagram at Bus 1……………………………………....... 99
Fig. 4.9: Three Phase Fault at Bus 1…………………………………………………………… 102
Fig. 4.10: Positive Sequence Impedance Diagram at Bus 2…………………………………… 103
Fig. 4.11: Three Phase Fault at Bus 2 …………………………………………………………… 104
Fig. 4.12: Positive Sequence Impedance Diagram at Load 1……………………………………. 105
Fig. 4.13: Three Phase Fault at Load 1…………………………………………………………... 106
Fig. 4.14: Positive Impedance Diagram at Load 5………………………………………………. 107
Fig. 4.15: Three Phase Fault at Load 6…………………………………………………………... 108
Fig. 4.16: Positive Sequence Impedance Diagram at Bus 1 for a Line to Ground Fault………... 109
Fig. 4.17: Cero Sequence Impedance Diagram at Bus 1……………………………………........ 109
Fig. 4.18: Line to Ground Fault at Bus 1………………………………………………………… 110
Fig. 4.19: Positive Sequence Impedance Diagram at Bus 2 for a Line to Ground Fault………... 111
Fig. 4.20: Cero Sequence Impedance Diagram at Bus 2………………………………………… 111
Fig. 4.21: Line to Ground Fault at Bus 2………………………………………………………… 112
Fig. 4.22: Positive Sequence Impedance Diagram at Load 1 for a Line to Ground Fault………. 113
Fig. 4.23: Cero Sequence Impedance Diagram at Load 1……………………………………….. 113
Fig. 4.24: Line to Ground Fault at Load 1……………………………………………………….. 114
Fig. 4.25: Positive Sequence Impedance Diagram at Load 5 for a Line to Ground Fault………. 115
Fig. 4.26: Cero Sequence Impedance Diagram at Load 5……………………………………….. 115
Fig. 4.27: Line to Ground Fault. At Load 5……………………………………………………... 116
Fig. 4.28: Positive Sequence Impedance Diagram at Generator Bus……………………………. 117
Fig. 4.29: Positive Sequence Impedance Diagram at Bus 2 using Generators………………….. 118
Fig. 4.30: Positive Sequence Impedance Diagram at Load 1 using Generators………………… 119
Fig. 4.31: Positive Sequence Impedance Diagram at Load 5 using Generators………………… 120
Fig. 4.32: Positive Sequence Impedance Diagram at Generators Bus for a Line to Ground Fault. 121
Fig. 4.33: Cero Sequence Impedance Diagram at Generators Bus………………………………. 121
Fig. 4.34: Positive Sequence Impedance Diagram at Bus 2 Using Generators for a Line to Ground
Fault……………………………………………………………………………………………… 122
Fig. 4.35: Cero Sequence Impedance Diagram at Bus 2 Using Generators……………………... 123
Fig. 4.36: Positive Sequence Impedance Diagram at Load 1 Using Generators for a Line to Ground
Fault……………………………………………………………………………………………… 124
Fig. 4.37: Cero Sequence Impedance Diagram at Load 1 Using Generators……………………. 124
Fig. 4.38: Positive Sequence Impedance Diagram at Load 5 Using Generators for a Line to Ground
Fault……………………………………………………………………………………………… 125
Fig. 4.39: Cero Sequence Impedance Diagram at Load 5 Using Generators……………………. 125
Fig. 4.40: Fault Simulation at Primary Side of 38KV/4.16KV Utility Transformer of BWWTP. 140
Fig. 4.41: Sequence of Operations Events at Primary Side of T1……………………………….. 141
Fig. 4.42: Fault Simulation at Bus 1 of BWWTP………………………………………………... 144
Fig. 4.43: Sequence of Operation Events at Bus 1………………………………………………. 145
Fig. 4.44: Fault Simulation at Bus 2 of BWWTP………………………………………………... 148
Fig. 4.45: Sequence of Operation Events at Bus 2………………………………………………. 149
Fig. 4.46: Fault Simulation at Load 1 of BWWTP……………………………………………… 152
Fig. 4.47: Sequence of Operations Events at Load 1……………………………………………. 153
Fig. 4.48: Fault Simulation at Load 6 of BWWTP……………………………………………… 156
Fig. 4.49: Sequence of Operation Events at Load 6……………………………………………... 157
Fig. 4.50: Recommendations to Fuse Protection………………………………………………… 161
Fig. 4.51: Time Fuse 1 and 5 Coordination……………………………………………………… 162
Fig. 4.52: Characteristics Curves for Fuse 1 and 5……………………………………………… 163
Fig. 4.53: Fuse 1 and 5 recommended…………………………………………………………… 164
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7. Fig. 4.54: Time Fuse 2 and 6 Coordination……………………………………………………… 165
Fig. 4.55: Characteristics Curves for fuse 2 and 6………………………………………………. 166
Fig. 4.56: Fuse 2 and 6 Recommended………………………………………………………….. 166
Fig. 4.57: Time Fuse 3, 4, 7 and 8 Coordination………………………………………………… 167
Fig. 4.58: Characteristics Curves for fuses 3, 4, 7 and 8………………………………………… 168
Fig. 4.59: Fuse 3, 4, 7 and 8 Recommended……………………………………………….......... 169
Fig. 4.60: Time Fuse 9 Coordination……………………………………………………………. 170
Fig. 4.61: Characteristics Curves for fuse 9……………………………………………………... 171
Fig. 4.62: Fuse 9 Recommended………………………………………………………………… 172
Fig. 4.63: Relay 351A Settings…………………………………………………………………... 179
Fig. 4.64: Overcurent Relay Settings for Generator……………………………………………... 180
Fig. 4.65: Undervoltage, Overvoltage, Frequency of Power Relay for Generator………………. 180
Fig. 4.66: Three Phase Fault Results…………………………………………………………….. 183
Fig. 4.67: Line to Ground Fault Results…………………………………………………………. 184
Fig. 4.68: Three Phase Fault Results Using Generators…………………………………………. 185
Fig. 4.69: Line to Ground Fault Results Using Generators…………………………………........ 185
Fig. 6.1: Protective Devices……………………………………………………………... 213
Fig. 6.2: Budget to Complete Design……………………………………………………. 218
Fig. 6.3: Salary Cap……………………………………………………………………… 218
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8. Chapter 1: General Information
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9. Contents
1.1 Abstracto……………………………………………………………………………... 10
1.2 Abstract………………………………………………………………………………. 11
1.3 Introduction…………………………………………………………………………... 12
1.4 Objectives…………………………………………………………………………….. 14
1.5 Constraints…………………………………………………………………………..... 15
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10. 1.1 Abstracto
La protección de los sistemas de potencia es uno de los campos más importantes
dentro del área de potencia en la ingeniería eléctrica. A través del tiempo se han creado
muchísimos programas de computadora con el fin de analizar diseños eléctricos. Nuestro
proyecto consiste en preparar una guía de usuario fácil de entender acerca de un programa
existente, llamado ETAP, diseñado para realizar análisis de protección de sistemas de
potencia. Esta guía de usuario debe incluir como crear un diagrama monolineal, como
configurar los equipos de protección, y también la forma correcta de hacer un análisis de
fallas y de corto circuito. Finalmente, nosotros preparamos una guía de usuario avanzada
con explicaciones detalladas sobre aplicaciones especiales y conceptos técnicos manejados
en el programa ETAP. También, como requisito de nuestro proyecto se analiza un caso
estudio de un sistema de potencia y se realiza la coordinación de protección del mismo.
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11. 1.2 Abstract
Power Protection is one of the most important fields in Power Electrical
Engineering. Through time many software’s has been created to analyze electrical designs.
Our project consist of prepare a user guide easy to understand of how to use an existing
power protection analysis program calling ETAP. This user guide must include how to
create a one-line diagram, how to configure power system devises, and an explanation of
the right way to perform a short and fault analysis. Finally, we prepare an advance user
guide with detailed explanations of special features and technical concept of ETAP
program. Also, as a requirement of our project, we analyzed a case study of power system
and perform the protective device coordination of it.
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12. 1.3 Introduction
Electricity has been a subject of scientific interest since at least the early 17th
century. Probably the first electrical engineer was William Gilbert who designed the
versorium: a device that detected the presence of statically charged objects. He was also the
first to draw a clear distinction between magnetism and static electricity and is credited
with establishing the term electricity. However it was not until the 19th century that
research into the subject started to intensify. Notable developments in this century include
the work of Georg Ohm, who in 1827 quantified the relationship between the electric
current and potential difference in a conductor, Michael Faraday, the discoverer of
electromagnetic induction in 1831, and James Clerk Maxwell, who in 1873 published a
unified theory of electricity and magnetism in his treatise on Electricity and Magnetism.
They are the fathers of electrical engineering and the electric systems.
Today, power system protection is that part of electrical power engineering that
deals with protecting the electrical power system from faults by isolating the faulted part
from the rest of the network.
Any electric power system involves a large amount of auxiliary equipment for the
protection of generators, transformers, and the transmission lines. Circuit breakers are
employed to protect all elements of a power system from short circuits and overloads, and
for normal switching operations.
The principle of a protection scheme is to keep the power system stable by isolating
only the components that are under fault, even as leaving as much of the network as
possible still in operation. Thus, protection schemes must apply a very pragmatic and
pessimistic approach to clearing system faults. For this reason, the technology and
philosophies utilized in protection schemes are often old and well-established because they
must be very reliable.
In much the same way as the early computers of the 1950s and 1960s were a
precursor to the computational capabilities of today’s computers. Specialized hardwire
systems were developed for locally monitoring the operation of power plants and for
remotely monitoring and controlling switches in transmission substation. The Remote
Terminal Units of these early monitoring systems were implemented with relay logic, while
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13. the master station consisted primarily of large banks of annunciator panels with red and
green light indication the state of the points being monitored with flashing light indication a
change in state or an alarm condition.
The impact of computers has nowhere been more revolutionary than in electrical
engineering. The design, analysis and operation of electrical and electronic systems has
become completely dominated by computers, a transformation that has been motivated by
the natural ease of interface between computers and electrical systems, and the promise of
spectacular improvements in speed and efficiency.
Our project consists of develop a protective device coordination using a graphical
software program to add features and flexibility in the area of electrical system protection.
Also, this graphical software program it’s going to be using for all kind of element that
used these. We will select the software program, analyze all types of element protection
that are utilizing in electrical systems, and simulate the program using various management
studies.
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14. 1.4 Objectives
• To make a research about technical references of fuses, relays and breakers.
• Understand technical data format of protection devices.
• To learn how to use the protective device coordination program.
• Create a user guide easy to understand about how to use software program.
• Build an advance use guide to explain additional features of software program.
• Perform a case study with the software program.
• Establish the system coordination of a case study with the program.
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15. 1.5 Constraints
• How to install ETAP program.
• Ways to use library of ETAP program. Start by understanding.
• Interpret results in the program.
• Establish coordination of a protection system.
• Run the program with all kind of requisites.
• Find right protective devices for design coordination.
• Understand how to program protective devices settings of equipments to use.
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16. Chapter 2: ETAP User Guide
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17. Contents
Basic ETAP User Guide………………………………………………………………………... 18
Creating a new ETAP Project………………………………………………………………….. 22
Opening an ETAP existing Project..……… ………………………………………… 23
Building New one-line Diagram. ……………………………………………………... 25
Connecting Elements……………………………………………………………… 28
Adding Protective Device to your One-Line………………………………………. 28
Verify if the element is connected………………………………………………… 29
Advance ETAP User Guide…..…………………………………………………………... 30
How to configure the elements in the one-line diagram…………………………… 34
Utility……………………………………………………………………… 34
High Voltage Circuit Breakers……………………………………………... 36
Low Voltage Circuit Breaker………………………………………………. 39
Protective Relay……………………………………………………………. 44
Fuses Ratings………………………………………………………………. 49
Transformer Properties………………………………………………..……. 54
Load Properties…………………………………………………………….. 57
Bus…………………………………………………………………………. 58
Perform a Fault Analysis…………………………………………………………... 59
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18. 2.1 Basic ETAP User Guide
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19. Page 19 of 263

20. Contents
Creating a new ETAP Project. ...................................................................................................... 22
Opening an ETAP existing Project. .............................................................................................. 23
Building New one-line Diagrams. ................................................................................................ 25
Connecting Elements. ................................................................................................................... 28
Adding a Protective Device to your One-Line. ............................................................................ 28
Verify if the element is connected. ............................................................................................... 29
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21. Table of Figure
Fig. 2.1: Create New Project Panel .................................................................................................... 22
Fig. 2.2: User Information Panel ....................................................................................................... 22
Fig. 2.3: Starting up window ............................................................................................................. 23
Fig. 2.4: Open Panel .......................................................................................................................... 24
Fig. 2.5: Selecting Project.................................................................................................................. 24
Fig. 2.6: Mode Toolbar ...................................................................................................................... 25
Fig.2.7: ETAP Elements .................................................................................................................... 27
Fig. 2.8: Connecting Elements .......................................................................................................... 28
Fig. 2.9: Open Panel .......................................................................................................................... 28
Fig. 2.10: Elements not connected..................................................................................................... 29
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22. 2.1.1 Creating a new ETAP Project.
Open the program and select new project. Write the name of the new project and select ok.
Fig. 2.1: Create New Project Panel
Write the name of the project user and select the access level permissions.
Fig. 2.2: User Information Panel
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23. 2.1.2 Opening an ETAP existing Project.
Select open on the ETAP screen.
Fig. 2.3: Starting up window
To open an existing project must be selected the icon showed. Click the icon and select
the project that you want to run in program.
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24. For example, select document named Protection System Devices and wait until in the next
page appears (Fig. 2.5)
Fig. 2.4: Open Panel
Select icon that has the ETAP symbols. Then click open to see the project at ETAP main
window.
Fig. 2.5: Selecting Project
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25. 2.1.3 Building New one-line Diagrams.
To build or edit a one-line diagram in ETAP, you must be in Edit Mode. Click the Edit
button on the Mode toolbar.
Fig. 2.6: Mode Toolbar
AC Elements:
= Pointer = Bus
= 2 winding transformers = 3 winding transformers
= cable = Transmission Line
= Reactors, Current-Limiting = Impedance
= Power grid = Generator
= Wind turbine Generator = Induction Machine
= Synchronous Motor = Lumped Load
= MOV = Static Load
= Capacitor = Harmonic Filter
= Remote Connector = Static Var Compensator
= HV DC Transmission Link = AC Composite Motor
= Composite Network = Fuse
= Contactor = High Voltage Circuit
Breaker
= Low Voltage circuit Breaker = Single Throw Switch
= Double Throw Switch = Instrumentation
= Ground Grid = Display options
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26. = Schedule Report Manager = Current Transformer (CT)
= Potential Transformer (PT) = Voltmeter
= Ammeter = Multi-meter
= Voltage Relay = Reverse Power Relay
= Frequency Relay = MV solid State Trip
Relay
= Motor Relay = Overcurrent Relay
= Overload Heater = Multi-Function Relay
= Tag Link
DC Elements:
= Pointer = Bus
= DC Cable = DC Impedance
= DC-DC Converter = Battery
= DC Motor = DC static Load
= DC Lumped Load = Composite CSD
= DC Composite Motor = Composite Network
= DC Circuit Breaker = DC Fuse
= DC Single Throw Switch = DC Double Throw
Switch
= Un-Interrupted Power System = Variable Frequency Drive
= Charger = Inverter
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27. You can select the element that your project requires for run the short circuit analysis. In
the columns you can see all the elements that ETAP program has. Select the elements and
drop to the board to complete your diagram.
Fig.2.7: ETAP Elements
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28. 2.1.4 Connecting Elements.
To connect the elements in the one-line. Use the mouse pointer over the connection pin of
an element, and it will turn red. Then click and drag to the connection pin of another
element. Follow this procedure to connect all the elements on the one-line. In the case of
buses, the entire element graphic functions as a connection point.
Fig. 2.8: Connecting Elements
2.1.5 Adding a Protective Device to your One-Line.
To connect the element between two elements does not require delete the line connecting
the elements. The element will automatically connect to the line. As shown in the diagram.
Fig. 2.9: Open Panel
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29. 2.1.6 Verify if the element is connected.
To check if an element is energized click on the continuity icon ( )
located in the project toolbar. All elements that are not energized will
be grayed out. For example, with the continuity check on, open CB4.
As shown in the figure to the right, CB4 and elements downstream
are grayed out.
Fig. 2.10: Elements not connected
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30. 2.2 Advance ETAP User Guide
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31. Page 31 of 263

32. Contents
How to configure the elements in the one-line diagram. .............................................................. 34
A) Utility ............................................................................................................................. 34
B) High Voltage Circuit Breakers ....................................................................................... 36
C) Low Voltage Circuits Breakers ...................................................................................... 39
D) Protective Relay ............................................................................................................... 44
E) Fuses Ratings .................................................................................................................... 49
F) Transformer Properties: ................................................................................................. 54
G) Load Properties: .............................................................................................................. 57
H) Bus ..................................................................................................................................... 58
Perform a Fault Analysis; ............................................................................................................. 59
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33. Table of Figures
Fig. 2.11: Power Grid Editor Window .............................................................................................. 34
Fig. 2.12: High Voltage Circuit Breaker Editor Window .................................................................. 36
Fig. 2.13: Circuit Breaker Library ..................................................................................................... 37
Fig. 2.14: Low Voltage Circuit Breaker Window ............................................................................. 39
Fig. 2.15: Low Voltage Circuit Breaker library ................................................................................ 41
Fig. 2.16: Overcurent Relay Editor Window ..................................................................................... 44
Fig. 2.17: Overcurrent Settings Panel ................................................................................................ 45
Fig. 2.18: Instantaneus Settings Panel ............................................................................................... 46
Fig. 2.19: Fuse Editor Window ......................................................................................................... 49
Fig. 2.20: Fuse Library Window ....................................................................................................... 51
Fig. 2.21: Winding Transformer Editor Window .............................................................................. 54
Fig. 2.22: Transformer Rating Editor Window ................................................................................. 55
Fig. 2.23: Transformer Tap Editor Window ...................................................................................... 56
Fig. 2.24: Lumped Load Editor Window........................................................................................... 57
Fig. 2.25: Bus Editor Window ........................................................................................................... 58
Fig. 2.26: Fault Simulation ................................................................................................................ 59
Fig. 2.27: Select Sequence Viewer to find fault analysis results ....................................................... 60
Fig. 2.28: Results Window ................................................................................................................ 60
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34. 2.2.1 How to configure the elements in the one-line diagram.
A) Utility
Rated kV
Enter the rated voltage of the power grid in kilovolts (kV).
Fig. 2.11: Power Grid Editor Window
Generation Categories
This group is used to assign the different power settings to each of the ten generation
categories for this power grid. Each grid can be set to have a different operating power
level for each generation category. Depending on the operation mode, some of the values
become editable as follows:
• Swing Mode: %V and angle
• Voltage Control Mode: %V and MW
• Mvar Control: MW and Mvar
• Power Factor Control: MW and PF
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35. SC Rating MVAsc
Specify the short-circuit MVA for three-phase and single-phase (line-to-ground) faults. As
you enter or modify MVAsc or X/R, ETAP recalculates the corresponding short-circuit
impedance values.
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36. B) High Voltage Circuit Breakers
How to change the Rating
• Click on either the ANSI or IEC option button to select that standard.
Fig. 2.12: High Voltage Circuit Breaker Editor Window
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37. Library Info
To access ANSI standard library data, click on the ANSI selection and then click on the
Library button. Use the same procedure for accessing IEC standard library data. As you
change the standard from ANSI to IEC, the data fields change accordingly.
Rating, ANSI Standard
Click on ANSI to enter high voltage circuit breaker ratings according to the ANSI
standards. Select the manufacturer and breaker model.
Fig. 2.13: Circuit Breaker Library
Max kV
Select the rated maximum kV of the high voltage circuit breaker in rms kV or select the
rating from the list box.
Continuous Amp
Select the continuous current rating of the high voltage circuit breaker in amperes or select
the rating from the list box.
Standard
Select the high voltage circuit breaker type as Symmetrical or Total rated from the list box.
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38. Cycle
Select the rated interrupting time for AC high voltage circuit breakers in cycles from the list
box.
CB Cycle Description
2 2-cycle ac high voltage circuit breakers with 1.5-cycle Minimum Contact Parting Time
3 3-cycle ac high voltage circuit breakers with 2-cycle Minimum Contact Parting Time
5 5-cycle ac high voltage circuit breakers with 3-cycle Minimum Contact Parting Time
8 8-cycle ac high voltage circuit breakers with 4-cycle Minimum Contact Parting Time
Rated Interrupting
Enter the rated short-circuit current (rated interrupting capability) at the rated maximum kV
in rms kA or select the rating from the list box.
Maximum Interrupting
Enter the maximum symmetrical interrupting capability in rms kA or select the rating from
the list box.
C & L RMS
Enter the closing and latching capability of the high voltage circuit breaker in asymmetrical
rms kA. This value is equal to 1.6 times the maximum interrupting capability.
C & L Crest
Enter the closing and latching capability of the high voltage circuit breaker in crest kA.
This value is equal to 2.7 times the maximum interrupting capability.
Page 38 of 263

39. C) Low Voltage Circuits Breakers
Standard
Click on either the ANSI or IEC option button to select that standard. Note: once the
breaker is selected from the breaker Library Quick Pick the standard is set based on the
library entry and is display only.
Type
Select a type from the drop-down list and display the type of breaker. Low voltage circuit
breakers include Molded Case, Power, and Insulated Case breakers. Once the breaker is
selected from the breaker Library Quick Pick, the LVCB type is set based on the library
entry and is display only.
Fig. 2.14: Low Voltage Circuit Breaker Window
Page 39 of 263

40. CB and Trip Device library
The low voltage circuit breaker data for a selected standard and type can be selected by
clicking on the Library button.
Standard
Click on either the ANSI or IEC option to select that standard. Note that the Standard
selection in the breaker library Quick Pick (and hence the breaker models displayed) will be
defaulted to the selection.
AC/DC
Displays that the LV breaker is AC. This option is grayed out and is not available for
editing.
Type
Select from the drop down list and display the breaker type. The LV breaker types include
Molded Case, Power and Insulated Case breakers. Note that the Type selection in the
breaker library Quick Pick (and hence the breaker models displayed) will be defaulted to
the selection made for the breaker type on the Rating page. The breaker type selection can
be changed on the Quick Pick if desired.
Page 40 of 263

41. Manufacturer Name
This displays a list of all AC LV breaker manufacturers included in the library for the
selected breaker standard and type. To choose one, just select the manufacturer name.
Fig. 2.15: Low Voltage Circuit
Breaker library
Reference
This displays the Manufacturer reference, if available. For example, Westinghouse is the
reference for Cutler Hammer.
Page 41 of 263

42. Model Name
The Model section displays list of all models for the selected standard, breaker type and
breaker manufacturer. The models are displayed in the form of Model – Max kV – Pole,
which forms a unique record name in the breaker library. Select the Model – Max kV –
Pole by highlighting it.
ANSI Short-Circuit data
When ANSI standard is selected, the short-circuit data shows the applied voltage in kV,
short-circuit interrupting current for the applied voltage in kA, and test power factor in %,
for all breaker types. The short-circuit parameters are explained in more detail in the
Ratings section. Select a desired applied voltage and short-circuit data by highlighting it.
Size
This displays a list of all sizes available for the selected Model, Max. kV, and Pole record
for the breaker. To select a size from the Library Quick Pick, highlight the size.
Ratings, ANSI Standard
Click on ANSI standard button and choose the breaker type to enter the ratings for LV
circuit breaker in accordance with the ANSI/IEEE standards. When a breaker is selected
from Library Quick Pick, all parameters shown below will be set to their corresponding
values chosen from the Quick Pick. With the exception of Size, changing the values after
selecting a breaker from Library Quick Pick will turn the header blue to indicate that the
substituted library data has been modified.
Size
Select an item from the drop-down list to display the size in amperes for the selected
breaker.
Page 42 of 263

43. Continuous Amp
Select an item from the drop-down list or enter the continuous current rating for the low
voltage circuit breaker in amperes. The Continuous Amp value will be set equal to the
breaker size when a breaker is selected from the breaker Library Quick Pick.
Rated kV
Select an item from the drop-down list or enter the rated kV rating for the low voltage
circuit breaker in kV. When a breaker is selected, the rated kV value will be set equal to
the applied kV selected from Library.
Test PF
This is the power factor of test equipment on which the rating of the circuit breaker has
been established. When a breaker is selected, the Test PF is set to the Test PF value
selected from Library.
Fused
For all breaker types, select fused or unfused by clicking on the provided selection box.
Note that when a breaker is selected from library, the Fused checkbox is set to the status as
selected from the Quick Pick. The value of Test PF will change appropriately for fused or
unfused type, in case of Power breakers.
Interrupting kA
Select from drop down list or enter the Interrupting kA rating for the low voltage circuit
breaker in kA. Note that when a breaker is selected, the interrupting kA value will be set
equal to the kA value for selected applied kV from library Quick Pick.
Page 43 of 263

44. D) Protective Relay
Fig. 2.16: Overcurent Relay Editor Window
Library
To access the Overcurrent relay library data, click on the Library button. Clicking the
Library button displays the relay library Quick Pick. From the Library, select the relay by
highlighting the Manufacturer name and Model name. Then click on the OK button to
retrieve the selected data from the library and transfer it to the editor.
OC level
Overcurrent relays can have multiple Time overcurrent (TOC) and/or Instantaneous
overcurrent (IOC) elements that can simultaneously and independently set in the relay
library. The OC level displays a drop down list of the maximum number of overcurrent
levels that are available for the selected relay.
Page 44 of 263

45. Overcurrent (51) Settings
The Time overcurrent settings available for Phase, Neutral, Ground, Sensitive Ground and
Negative Sequence are described below.
Fig. 2.17: Overcurrent Settings
Panel
Pickup Range
Select from drop down list and display the Time overcurrent Pickup range for the selected
curve. The pickup range can be specified in amperes of the secondary or primary current
rating. It can also be in multiples/percent of the CT secondary.
Pickup Setting
For the selected pickup range, select or enter the Time overcurrent pickup setting. The
pickup setting can be discrete values or continuously adjustable.
Relay Amps
This field displays the relay secondary current in amperes, for the selected pickup setting.
Prim. Amps
This field displays the relay primary current in amperes, for the selected pickup setting.
Page 45 of 263

46. Time Dial
Select and display the Time Dial for the selected curve type. The time dial can be discrete
values or continuously adjustable.
Instantaneous (50) Settings
The Instantaneous settings available for Phase, Neutral, Ground, Sensitive Ground and
Negative Sequence are described below.
Fig. 2.18: Instantaneus Settings Panel
Page 46 of 263

47. Curve Type
This field with a drop down list of curves is available only if the selected relay has Short
time feature and if the Short time is selected. Select from the drop down list and display
the Short time curve type for the selected model.
Pickup Range
Select from the drop down list and display the Instantaneous Pickup range (for the selected
curve in case of Short time). The pickup range can be specified in amperes of the
secondary or primary current rating. It can also be in multiples/percent of the CT secondary
or 51 pickup.
Pickup Setting
For the selected pickup range, select or enter the Instantaneous pickup setting. The pickup
setting can be discrete values or continuously adjustable.
Relay Amps
This field displays the relay secondary current in amperes, for the selected pickup setting.
Prim. Amps
This field displays the relay primary current in amperes, for the selected pickup setting.
Delay Range
This field is available only if the relay has Instantaneous function. Select from the drop
down list and display the Instantaneous Delay range. The delay range could either be in
seconds or cycles.
Delay
Select or enter the intentional delay for the instantaneous. The Delay can be in seconds or
cycles, depending on the selection of relay. The delay can be in the form of discrete values
or continuously adjustable.
Page 47 of 263

48. Time Dial
This field is available only if the selected relay has Short time feature and if the Short time
is selected. Select or enter the Time Dial for the selected curve type. The time dial can be
discrete values or continuously adjustable.
Page 48 of 263

49. E) Fuses Ratings
Standard
Click either the ANSI or IEC button option to select that standard. Once the fuse is
selected from the Library Quick Pick - Fuse, the standard is set based on the library entry
and is display only.
Rating, ANSI Standard
Click on ANSI standard to enter the ratings for Fuse in accordance with the ANSI/IEEE
standards. When a Fuse is selected from library Quick Pick, all parameters shown below
will be set to their corresponding values chosen from the Quick Pick. With the exception of
Size, changing the value(s) after selecting a fuse from library Quick Pick will turn the
header to blue color indicating that the substituted library data has been modified.
Fig. 2.19: Fuse Editor Window
Page 49 of 263

50. kV
Select from drop down list or enter the rated kV rating for the Fuse in kV. When a Fuse is
selected, the Rated kV value will be set equal to the Max. kV selected from library Quick
Pick.
Size
Select from the drop-down list and display the size in amperes for the selected fuse. Note:
the Size field will be empty when no fuse is chosen from Library Quick Pick.
Continuous Amp
Select from drop down list or enter the continuous current rating for the Fuse in amperes.
The Continuous Amp value will be set equal to the fuse size when a fuse is selected from
library Quick Pick.
Interrupting
Select from the drop-down list or enter the Interrupting kA rating for the Fuse in kA. Note:
when a Fuse is selected, the interrupting kA value will be set equal to the kA value for
selected fuse size from Library Quick Pick.
Test PF
Enter the power factor of test equipment on which the rating of the fuse has been
established. When a fuse is selected, the Test PF is set to the Test PF value selected from
library Quick Pick.
Page 50 of 263

51. Library (Quick Pick)
To select a fuse from the library, click the Library button and the Library Quick Pick – Fuse
dialog box will appear. From the dialog box, select a fuse by selecting the Manufacturer
name and the desired fuse Model, Max kV, and Speed. This represents a unique record.
Select the desired size and short circuit interrupting kA. Then click the OK button to
retrieve the selected data from the library and transfer it to the editor.
Fig. 2.20: Fuse Library Window
Standard
Click on either the ANSI or IEC option to select that standard. Note that the Standard
selection in the Fuse library Quick Pick (and hence the fuse models displayed) will be
defaulted to the selection made for the standard on the Rating page. The standard selection
can be changed on the Quick Pick if desired.
Page 51 of 263

52. Manufacturer
Manufacturer Name
Displays a list of all AC Fuse manufacturers included in the library for the selected
standard. Select the manufacturer by highlighting the manufacturer name.
Reference
Displays a manufacturer reference, if available, for selected manufacturer. For example,
Siemens is the reference manufacturer for ITE.
Model Name
The Model section displays list of all fuse models for the selected standard and fuse
manufacturer. The models are displayed in the form of Model – Max kV – Speed, which
forms a unique record name in the fuse library. Select the Model – Max kV – Speed by
highlighting it.
Cont. Amp
This displays the ampere value corresponding to each size for the selected fuse model.
Int. kA (ANSI Standard)
This displays the short-circuit interrupting rating in kA corresponding to each size for the
selected ANSI fuse model.
Model Info
Class
This displays the class (E-rated, for example) for the selected fuse model.
Page 52 of 263

53. Type
This displays the type (Power Fuse, for example) for the selected fuse model.
Brand Name
It shows the brand name, if available, for the selected fuse model.
Reference
It demonstrates the reference, if available, for selected fuse model.
Application
Present the application for the selected fuse model.
Page 53 of 263

54. F) Transformer Properties:
You can open the editor for T2 and go to the Rating page. On the rating page you can enter
the value of the primary kV, secondary kV, primary winding rating in kVA or MVA, and
the maximum transformer rating. Additionally, you can enter the impedance or substitute
typical values for the transformer.
Fig. 2.21: Winding Transformer Editor Window
Page 54 of 263

55. Transformer Ratings
Fig. 2.22: Transformer Rating Editor Window
Rating of Transformer:
Enter the rating of KV primary and secondary.
Enter the rating of MVA.
Enter the Typical X/R.
Enter the Z variation and Z Tolerance.
You may select the typical rating.
Page 55 of 263

56. Transformer Tap
The Transformer Tap Optimization calculation optimizes a unit transformer tap, or
equivalently, its turn ratio, to ensure that the generator unit voltage remains within its upper
and lower variation range (typically 95% to 105%), while producing its full MW and Mvar
capability under the system voltage variation.
Fig. 2.23: Transformer Tap Editor Window
Page 56 of 263

57. G) Load Properties:
In this part you can go to the Nameplate page. The available fields in the rating section depend
on the Model Type selected. In the Ratings section enter the lumped load rating in MVA or
MW. Furthermore, the % loading for various loading categories can be specified here.
Fig. 2.24: Lumped Load Editor Window
Page 57 of 263

58. H) Bus
Nominal kV
Enter the nominal voltage of the bus in kilovolts (kV).
In/Out of Service
The operating condition of a bus can be selected by choosing either the In Service or Out of
Service option.
Fig. 2.25: Bus Editor Window
Page 58 of 263

59. 2.2.2 Perform a Fault Analysis;
Star View:
Click Star Protective Device Coordination.
Fig. 2.26: Fault Simulation
Page 59 of 263

60. Select Sequence Viewer to find the result of the Protective Device Cordination.
Fig. 2.27: Select Sequence Viewer to
find fault analysis results
It will show the results to be show in the report. The sequence of operation is on order to
the parameters of the system.
Fig. 2.28: Results Window
Page 60 of 263

61. Chapter 3: Transformer Case
Study
Page 61 of 263

62. Contents
Diagrams………………………………………………………………………………… ..64
Equipment Data……………………………………………………………………………66
Calculations………………………………………………………………………………..68
Coordination Using ETAP Program……………………………………………………….73
Fault Simulation……………………………………………………………………………77
Results………………...……………………………………………………………………81
Page 62 of 263

63. Table of Figures
Fig. 3.1: Transformer Protection Diagram……………………………………………………....... 65
Fig. 3.2: Selected Fuse…………………………………………………………………………….. 67
Fig. 3.3: Selected Relay…………………………………………………………………………… 67
Fig. 3.4: Table of Current Transformer Specifications…………………………………………… 67
Fig. 3.5: Table of Power Fuse Rating……………………………………………………………... 71
Fig. 3.6: Overcurrent Relay Settings at Transformer……………………………………………... 74
Fig. 3.7: Overcurrent Relay Settings at Load 1,2…………………………………………………. 75
Fig. 3.8: Fuse Settings…………………………………………………………………………….. 76
Fig. 3.9: ETAP Simulation of Fault at Bus 1……………………………………………………… 78
Fig. 3.10: Sequence of Operation Events at Bus 1………………………………………………... 78
Fig. 3.11: ETAP Fault Simulation at Bus 2……………………………………………………….. 79
Fig. 3.12: Sequence of Operation Events at Bus 2………………………………………………... 79
Fig. 3.13: ETAP Fault Simulation at Load 1……………………………………………………… 80
Fig. 3.14: Sequence of Operation Events at Load 1………………………………………………. 80
Fig. 3.15: Relay and Fuse Settings………………………………………………………………... 83
Fig. 3.16: Results of Short Circuit Analysis………………………………………………………. 83
Page 63 of 263

64. 3.1 Diagrams
Page 64 of 263

65. 3.1.1 Transformer Case Study Diagram:
Fig. 3.1: Transformer Protection Diagram
Our Transformer Case Study has the following components:
a) One transformer 38/4.16 KV of 7.5/11.3 MVA.
b) Two feeders.
Protection has to be able to extinguish faults that affect the system. It scheme consist of
protective relaying and fuses. Coordination criteria have 22 cycles between protection levels.
We considered selectivity, reliability and simplicity to accomplish with a scheme protection
safety.
Page 65 of 263

66. 3.2 Equipment Data
Page 66 of 263

67. Equipment Data:
Specification of electric fuse
Fuse
Continuous Maximum
Fuse Name Size Type
Amperes KV
Cutler Hammer Standard
150E 150 17
BA-200 Speed
Fig. 3.2: Selected Fuse
Relay settings
Relay
TOU
IOU
Location Relay Name 51 & Curve
50 & 50N
51N
ABB 51D
0.5-80; 0.5-80; Extremely
Feeder with 50
0.1 steps 0.1 steps Inverse
(60Hz)
ABB 51D
Main 0.5-80; 0.5-80; Very
with 50
Breaker 0.1 steps 0.1 steps Inverse
(60Hz)
Fig. 3.3: Selected Relay
Selected current transformer
Current Transformer
Location CTR Type
Main
2,500/5 MR C400
Breaker
Load 800/5 MR C400
Fig. 3.4: Table of Current Transformer Specifications
Page 67 of 263

68. 3.3 Calculations
Page 68 of 263

69. Power System Coordination calculation:
1) Calculating the short circuit current:
375MVA
ISC = = = 5, 697.53 A
3(38 KV )
7.5MVA
IBASE = = 113.95 A
3(38 KV )
5, 697.53
I pu = = 50.0 pu
113.95
1
Z pu = = 0.02 pu
50.0
1∠00
ISC = = 11.11 p
0.02 + 0.07
 38 
IBASE = (113.95)   = 11,564.3 A
 4.16 
Page 69 of 263

70. 2) Calculating the multiples of the relay in the load, to verify the necessary time dial in the
curves:
11, 565.3
M= = 13.6
850
3) Obtaining the pick-up current for the relay in the transformer:
Pickup = (1568.28)(1.2) = 1881.93A
4) The multiples of the current transformer (CTM) in the transformer:
11,565.3
M= = 6.14
1,881.93
5) The calculation for choose the CTR:
CTR = 2000/5
11.3MVA
IFL = = 1, 568.28 A ISC = 11,565.04
3(4.16 KV )
a) CTR > 1,568.28(1.2) = 1,881.93A
b) ISC/CTR < 100 A
11,565.04/400 < 100
Page 70 of 263

71. 6) Calculation for choosing fusible:
Using the standard Speed curve
Step 1: Full load Current
11.3MVA 7.5MVA
IFL = = 171.68 A INM = = 113.95 A
3(38 KV ) 3(38 KV )
Data: 46 Kv Power Fuses (Show & Standard Speed)
Rating Continuous Current Operating Time
100E 165 See curves…
125E 181 See curves…
Fig. 3.5: Table of Power Fuse Rating
F1 ≥ 125E
Step 2: Inrush Current
IINRUSH = 113.95(12) = 1,367.48 A @ 6 cycles F1 ≥ 100E
Step 3: Short circuit current
11,564.3
ISC = = 1, 266.1A @ 43.2 cycles F1 ≥ 175E
 38 
 
 4.16 
Step 4: Turning Ratio
 I NOMINAL 
FR =   > 1.5 < 3
 I NOMINAL TRANS. 
 213 
=  = 1.86 1.5 < 1.86 < 3
 113.95 
The fuse chosen is 175E because it complied with the parameters of the design. Fuse will be
175E and can handle 213 Amps.
Page 71 of 263

72. Using the Slow Speed curve:
Step 1: Full load Current
11.3MVA
IFL = = 171.68 A
3(38 KV )
Data: 46 Kv Power Fuses (Slow & Standard Speed)
Rating Continuous Current Operating Time
100E 165 See curves…
125E 181 See curves…
Fig. 3.5: Table of Power Fuse Rating
F1 ≥ 125E
Step 2: Inrush Current
IINRUSH = 113.95(12) = 1,367.48 @ 6 ciclos F1 ≥ 80E
Step 3: Short circuit current
11,564.3
ISC = = 1, 266.1A @ 43.2 ciclos F1 ≥ 125E
 38 
 
 4.16 
Step 4: Turning Ratio
 I NOMINAL 
FR =   > 1.5 < 3
 I NOMINAL TRANS. 
 181 
=  = 1.58 1.5 < 1.58 < 3
 113.95 
The fuse chosen is 125E because it complied with the parameters of the design.
Page 72 of 263

73. 3.4 Coordination Using ETAP
Program
Page 73 of 263

74. Overcurrent:
To protect our transformer power system we choose a relay distributed by ABB
with overcurrent and instantaneous settings. This setting for overcurrent was given using a
Definite Time Curve. The pick range is specified by 5 amperes of the secondary or primary
rating. Using this setting the relay will operate when primary current exceed 2,500A. Time
dial of overcurrent relay is given by curve type and changing it by time required. In the
other side, to operate instantaneous relay is necessary select a pick up according to short
circuit current. These input settings are introduced at ETAP window showing below.
Overcurrent Relay settings in the transformer:
Fig. 3.6: Overcurrent Relay Settings at Transformer. In this
case the curve selected was Definite Time.
Page 74 of 263

75. Another section of our power system that required protection are load 1 and 2
feeders. To protect these feeders we select an ABB instantaneous and overcurrent relay.
The overcurrent settings were chosen by a Definite Time Curve. The pick range is
specified by 5 amperes of the secondary side of relay. Using this setting the overcurrent
will operate when line current exceed 850A. Time dial is given by relay curve according to
time required for current magnitude. In the other side, to operate instantaneous relay is
necessary select a pick up according to short circuit current. When current reach 11,568;
instantaneous protection must operate. These input settings are introduced at ETAP
window showing below.
Overcurrent relay setting at load 1,2:
Fig. 3.7: Overcurrent Relay Settings at Load 1,2
Page 75 of 263

76. Fuse Setting:
In order to perform good protective device coordination is necessary implement use of
almost one fuse. The fuse selected by us is S&C, SMU-20. It is modeling by an standard
speed curve with short circuit current of 10KA. Also it has a maximum rated voltage of
38KV. Finally, the size of fuse is 200E with a 200 continuous amperes.
Fig. 3.8: Fuse Settings
Page 76 of 263

77. 3.5 Fault Simulation
Page 77 of 263

78. Short circuit results:
Fig. 3.10: Sequence of Operation
Events at Bus 1
Fig. 3.9: ETAP Simulation of
Fault at Bus 1
Protection in the system can not protect for a fault at bus 1. It should be protected
by other protective device out of our system.
Page 78 of 263

79. Figures below show short circuit results at bus 2 when operate the instantaneous
relay 2. The instantaneous relay work to open the circuit and if it does not operate fuse 1
operate to disconnect system. Relay 2 operates at 2.75 cycles after a fault occurs. If relay 1
does not work, fuse 1 is going to operate at 52.56 cycles.
Fig. 3.12: Sequence of Operation Events at
Fig. 3.11: ETAP Fault Simulation at Bus 2 Bus 2
Page 79 of 263

80. In figures below you can see short circuit results at load 1. Instantaneous relay 3 will open
first. If it does not operate, time overcurrent relay 2. But, if it also does not work, fuse 1
must open with a time delay.
Fig. 3.14: Sequence of Operation Events at
Load 1
Fig. 3.13: ETAP Fault Simulation at Load 1
ETAP program gives results of short circuit. Short circuit current is 21,570 at load 1.
With this current we choose settings for relay 3. Short circuit at load 1 is the same results
at load 2.
Sequence operation work with a sequence coordination of 22 cycles approximated.
Relay 3 operates at 7.74 cycles covered by relay 2 witch operates at 28.86 cycles like
primary protection.
Page 80 of 263

81. 3.6 Settings and Results
Page 81 of 263

82. Settings and Results
We perform protective device coordination for a transformer and two loads. In
order to express our results and recommendations clearly, we organized all data in tables.
These tables include devices and fuse settings. In the figure 3.15 you can find curves type,
pick-up and time dial to obtain better results with the protective device coordination. In the
other side, three phase fault table contents short circuits results in different section of
system.
The figure 3.16 shows short circuit current magnitude in different parts of system.
First, the table presents a three phase fault at feeder #1. Short circuit current at this point is
11,564A. With this fault feeder relay will operates at 2.76 cycles like primary protection.
If the feeder relay does not operate, main breaker feeder will operate at 25.86 cycles.
When system has a fault at primary side of transformer #1, the fuse will operate at
52.56 cycles.
Relays in our system use definite time curve. It is use to chose time dial of relay
operation. In the other way, fuse 1 is modeling with a standard speed curve. Using these
settings the protection is complete according with coordination criteria.
Page 82 of 263

83. Equipment Settings
Equipment Settings
Time
Equipment Curve Pick-up
Dial
Feeder Definite
2,500 1.895
Relay Time
Main
Definite
Breaker 850 1.895
Time
Relay
Standard
Fuse X X
Speed
Fig. 3.15: Relay and Fuse Settings
Fault Results
Three Phase Fault
Short Operation Protection Devices
Localization
Circuit Feeder Main
Fault
Current Relay Breaker Fuse
(51) Relay (51)
Feeder #1 or 11,564
2.76 25.86 52.56
#2 A
11,566
Bus #2 X 2.76 52.56
A
10,500
T1 Primary X X 52.56
A
T1 Secondary 9,950 A X X X
Fig. 3.16: Results of Short Circuit Analysis
Page 83 of 263

84. Chapter 4: Bayamón WWTP
Coordination Study
Page 84 of 263

85. Contents
Scope……………………………………………………………………………………….. 88
Electrical System Oneline Diagram……………………………………………………….... 90
Imput Data Report………………………………………………………………………… 94
Calculations………………………………………………………………………………... 97
Short Circuit Study………………………………………………………………………. 138
Power Fuse Selection for Power Transformer T1, T2, T3, T4, T5, T6 and T7………….. 160
Protection Relay Settings for Distrbution Feeders………………………………………. 173
Relay Settings……………………………………………………………………………. 178
Results……………………………………………………………………………………. 181
Page 85 of 263

86. Table of Figure
Fig. 4.1: Power Transformer Characteristics Table………………………………………………... 89
Fig. 4.2: Generator Characteristics Table…………………………………………………………. 89
Fig. 4.3: Original Oneline Diagram of Bayamón WWTP………………………………………… 92
Fig. 4.4: Suggested Oneline Diagram of Bayamón WWTP………………………………………. 93
Fig. 4.5: Lines Cables……………………………………………………………………………... 95
Fig. 4.6: Existing Transformer Line Cable. ……………………………………………………… 95
Fig. 4.7: Generator Cables………………………………………………………………………… 95
Fig. 4.8: Positive Sequence impedance Diagram at Bus 1………………………………………... 99
Fig. 4.9: Three Phase Fault at Bus 1……………………………………………………………... 102
Fig. 4.10: Positive Sequence Impedance Diagram at Bus 2……………………………………... 103
Fig. 4.11: Three Phase Fault at Bus 2 …………………………………………………………… 104
Fig. 4.12: Positive Sequence Impedance Diagram at Load 1……………………………………. 105
Fig. 4.13: Three Phase Fault at Load 1…………………………………………………………... 106
Fig. 4.14: Positive Impedance Diagram at Load 5………………………………………………. 107
Fig. 4.15: Three Phase Fault at Load 6…………………………………………………………... 108
Fig. 4.16: Positive Sequence Impedance Diagram at Bus 1 for a Line to Ground Fault………... 109
Fig. 4.17: Zero Sequence Impedance Diagram at Bus 1……………………………………........ 109
Fig. 4.18: Line to Ground Fault at Bus 1………………………………………………………… 110
Fig. 4.19: Positive Sequence Impedance Diagram at Bus 2 for a Line to Ground Fault………... 111
Fig. 4.20: Zero Sequence Impedance Diagram at Bus 2………………………………………… 111
Fig. 4.21: Line to Ground Fault at Bus 2………………………………………………………… 112
Fig. 4.22: Positive Sequence Impedance Diagram at Load 1 for a Line to Ground Fault………. 113
Fig. 4.23: Zero Sequence Impedance Diagram at Load 1……………………………………….. 113
Fig. 4.24: Line to Ground Fault at Load 1……………………………………………………….. 114
Fig. 4.25: Positive Sequence Impedance Diagram at Load 5 for a Line to Ground Fault………. 115
Fig. 4.26: Zero Sequence Impedance Diagram at Load 5……………………………………….. 115
Fig. 4.27: Line to Ground Fault. At Load 5……………………………………………………... 116
Fig. 4.28: Positive Sequence Impedance Diagram at Generator Bus……………………………. 117
Fig. 4.29: Positive Sequence Impedance Diagram at Bus 2 using Generators………………….. 118
Fig. 4.30: Positive Sequence Impedance Diagram at Load 1 using Generators………………… 119
Fig. 4.31: Positive Sequence Impedance Diagram at Load 5 using Generators………………… 120
Fig. 4.32: Positive Sequence Impedance Diagram at Generators Bus for a Line to Ground Fault 121
Fig. 4.33: Zero Sequence Impedance Diagram at Generators Bus……………………………… 121
Fig. 4.34: Positive Sequence Impedance Diagram at Bus 2 Using Generators for a Line to Ground
Fault……………………………………………………………………………………………… 122
Fig. 4.35: Zero Sequence Impedance Diagram at Bus 2 Using Generators……………………... 123
Fig. 4.36: Positive Sequence Impedance Diagram at Load 1 Using Generators for a Line to Ground
Fault……………………………………………………………………………………………… 124
Fig. 4.37: Zero Sequence Impedance Diagram at Load 1 Using Generators……………………. 124
Fig. 4.38: Positive Sequence Impedance Diagram at Load 5 Using Generators for a Line to Ground
Fault……………………………………………………………………………………………… 125
Fig. 4.39: Zero Sequence Impedance Diagram at Load 5 Using Generators……………………. 125
Fig. 4.40: Fault Simulation at Primary Side of 38KV/4.16KV Utility Transformer of BWWTP. 140
Fig. 4.41: Sequence of Operations Events at Primary Side of T1……………………………….. 141
Fig. 4.42: Fault Simulation at Bus 1 of BWWTP………………………………………………... 144
Fig. 4.43: Sequence of Operation Events at Bus 1………………………………………………. 145
Fig. 4.44: Fault Simulation at Bus 2 of BWWTP……………………………………………….. 148
Fig. 4.45: Sequence of Operation Events at Bus 2………………………………………………. 149
Fig. 4.46: Fault Simulation at Load 1 of BWWTP……………………………………………… 152
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87. Fig. 4.47: Sequence of Operations Events at Load 1……………………………………………. 153
Fig. 4.48: Fault Simulation at Load 6 of BWWTP……………………………………………… 156
Fig. 4.49: Sequence of Operation Events at Load 6……………………………………………... 157
Fig. 4.50: Recommendations to Fuse Protection………………………………………………… 161
Fig. 4.51: Time Fuse 1 and 5 Coordination……………………………………………………… 162
Fig. 4.52: Characteristics Curves for Fuse 1 and 5……………………………………………… 163
Fig. 4.53: Fuse 1 and 5 recommended…………………………………………………………… 164
Fig. 4.54: Time Fuse 2 and 6 Coordination……………………………………………………… 165
Fig. 4.55: Characteristics Curves for fuse 2 and 6………………………………………………. 166
Fig. 4.56: Fuse 2 and 6 Recommended………………………………………………………….. 166
Fig. 4.57: Time Fuse 3, 4, 7 and 8 Coordination………………………………………………… 167
Fig. 4.58: Characteristics Curves for fuses 3, 4, 7 and 8………………………………………… 168
Fig. 4.59: Fuse 3, 4, 7 and 8 Recommended……………………………………………….......... 169
Fig. 4.60: Time Fuse 9 Coordination……………………………………………………………. 170
Fig. 4.61: Characteristics Curves for fuse 9……………………………………………………... 171
Fig. 4.62: Fuse 9 Recommended………………………………………………………………… 172
Fig. 4.63: Relay 351A Settings………………………………………………………………….. 179
Fig. 4.64: Overcurent Relay Settings for Generator……………………………………………... 180
Fig. 4.65: Undervoltage, Overvoltage, Frequency of Power Relay for Generator………………. 180
Fig. 4.66: Three Phase Fault Results…………………………………………………………….. 183
Fig. 4.67: Line to Ground Fault Results…………………………………………………………. 184
Fig. 4.68: Three Phase Fault Results Using Generators…………………………………………. 185
Fig. 4.69: Line to Ground Fault Results Using Generators…………………………………........ 185
Page 87 of 263

88. 4.1 Scope
Page 88 of 263

89. Scope
Develop a short circuit study for Power Transformers and relay settings for a waste
water treatment plant and the protective devices associated.
The Bayamón Waste Water Treatment Plant has seven large power
transformers with their respective protective devices (power fuses or
protective relaying) in service. The intention of this short circuit study is to
verify the appropriated protective device coordination and recommended the
appropriated changes if any.
For this plant we will cover the relay coordination and settings for the
protective device associated.
The short circuit current available at Bayamón Waste Water Treatment
Plant, with 38 kV connection tap, is submitted by Puerto Rico Electric
Authority (PREPA). Three phase short circuit current is 20,000 A and
11,547 A for phase to ground.
The ETAP Power Simulation computer program, version 5.5 from Operation
Technology, Inc was used for all the short circuit studies and simulations.
The following tables detail information available for the electrical
Fig. 4.1: Power equipment from the electrical drawings for Bayamón Waste Water
Transformer Treatment Plant. This information will be the data base for the short circuit
Characteristics
Table study.
Power Transformer
# T1 T2 T3 T4 T5 T6 T7
Characteristics
1 Voltage in kV 38/4.16 4.16/0.48 4.16/0.48 38/4.16 4.16/0.48 4.16/0.48 4.16/0.48
2 Capacity in MVA 5 1.5 1.5 5 1.5 1.5 0.15
3 Impedance in % 6.21 3 3 6.21 3 3 2.5
4 Connection D-Y D-Y D-Y D-Y D-Y D-Y D-Y
# Generator (1 to 2) Value Units SEL 300G
Characteristics
1 Terminal Voltage 4.16 kV
2 Capacity 2500 KW
3 Power Factor 0.8 Fig. 4.2: Generator
Characteristics
4 Full Load 347.37 Amps Table.
5 Synchronous Reactance 2.14
6 Transient Reactance 0.19
7 Substransient Reactance 0.14
8 Negative Sequence Reactance 0.19
9 Zero Sequence Reactance 0.05
Page 89 of 263

90. 4.2 Electrical System Oneline
Diagram
Page 90 of 263

91. Diagrams
We were required to perform an analysis for choose necessary equipment to protect
electric power system o Bayamón Waste Water Treatment Plant. After analizing the
system, we decided to use following coordination equation; t2 = 1.3t1 +15. Using it, we set
next coordination level between 23 to 25 cycles.
In order to find the best devices to perform a good protective device coordination,
we analized a lot of different devices. The selected devices are commonly used in power
systems. It help very much to find devices information. Selected fuses were exclusive to
accomplish all requirements. Chosen devices and results are showed through next pages.
Page 91 of 263

92. Bayamón WWTP Case Study
Fig. 4.3: Original Oneline Diagram of
Bayamón WWTP.
This is the original oneline diagram given to us with the objective of perform the
protective device coordination. It does not include any protective device.
Page 92 of 263

93. Bayamón WWTP Sugested Oneline Diagram
Fig. 4.4: Suggested Oneline Diagram of
Bayamón WWTP.
Above diagram shows all suggested protective devices for power system of
Bayamón WWTP. Each device was selected to guarantee the best protective device
coordination. Shortly we present complete analysis of this coordination.
Page 93 of 263

94. 4.3 Input Data Report
Page 94 of 263