ELECTRIC DISTRIBUTION
SYSTEMS
IEEE Press
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Giancarlo Fortino
David Alan Grier
Donald Heirman
Xiaoou Li
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Saeid Nahavandi
Ray Perez
Jeffrey Reed
Linda Shafer
Mohammad Shahidehpour
Sarah Spurgeon
Ahmet Murat Tekalp
SECOND EDITION
ELECTRIC DISTRIBUTION
SYSTEMS
ABDELHAY A. SALLAM
OM P. MALIK
Copyright © 2019 by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.
Published by John Wiley & Sons, Inc., Hoboken, New Jersey.
Published simultaneously in Canada.
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Library of Congress Cataloging-in-Publication Data is available.
ISBN: 978-1-119-50931-8
Cover design: Wiley
Cover images: (Top image) © Sam Robinson/Getty Images; (Center image) Courtesy of Om P. Malik
Printed in the United States of America.
10 9 8 7 6 5 4 3 2 1
CONTENTS
PREFACE
xi
ACKNOWLEDGMENTS
PART I
CHAPTER 1
1.1
1.2
1.3
1.4
2.1
2.2
2.3
3
3
DISTRIBUTION SYSTEM STRUCTURE
DISTRIBUTION SYSTEM PLANNING
LOAD FORECASTING
Introduction 41
Important Factors for Forecasts
Forecasting Methodology 43
Spatial Load Forecasting (SLF)
End-Use Modeling 64
Spatial Load Forecast Methods
9
9
Duties of Distribution System Planners
Factors Affecting the Planning Process
Planning Objectives 31
Solutions for Meeting Load Forecasts
CHAPTER 4
4.1
4.2
4.3
4.4
4.5
4.6
INTRODUCTION
Distribution Voltage Levels 9
Distribution System Configuration
General Comments 22
CHAPTER 3
3.1
3.2
3.3
3.4
FUNDAMENTAL CONCEPTS
Introduction and Background
Power System Structure 3
Distribution Level 5
General 7
CHAPTER 2
xiii
23
23
25
37
41
42
56
65
v
vi
CONTENTS
PART II
CHAPTER 5
5.1
5.2
5.3
5.4
5.5
8.1
8.2
8.3
9.1
9.2
9.3
9.4
9.5
9.6
9.7
9.8
163
166
PROTECTION: OTHER SCHEMES
207
223
SWITCHGEAR DEVICES
235
Need for Switchgear 235
MV Switchgear Devices 237
LV Switchgear Devices 244
Protection Classes 250
Specifications and Implementation of Earthing
Assessment of Switchgear 253
Safety and Security of Installations 255
Application Trends in MV Switchgear 256
CHAPTER 10
10.1
10.2
10.3
10.4
10.5
PROTECTION: CURRENT-BASED SCHEMES
Overvoltage Protection 207
Thermal Protection 220
Reclosers, Sectionalizers, Fuses
CHAPTER 9
111
113
Introduction 163
Types of Relay Construction
Overcurrent Protection 171
Directional Protection 187
Differential Protection 193
CHAPTER 8
75
104
SHORT-CIRCUIT STUDIES
Introduction 111
Short-Circuit Analysis
CHAPTER 7
7.1
7.2
7.3
7.4
7.5
EARTHING OF ELECTRIC DISTRIBUTION SYSTEMS
Basic Objectives 75
Earthing Electrical Equipment 76
System Earthing 93
MV Earthing Systems 99
Earthing Systems in LV Distribution Networks
CHAPTER 6
6.1
6.2
PROTECTION AND SWITCHGEAR
SWITCHGEAR INSTALLATION
Steps for Installing Switchgear 261
Switchgear Layout 262
Dimensioning of Switchgear Installations
Civil Construction Requirements 275
ARC-Flash Hazards 282
251
261
264
CONTENTS
PART III
CHAPTER 11
11.1
11.2
11.3
11.4
11.5
12.1
12.2
12.3
12.4
VOLTAGE VARIATIONS
321
POWER FACTOR IMPROVEMENT
361
HARMONICS IN ELECTRIC DISTRIBUTION SYSTEMS
379
396
HARMONICS EFFECT MITIGATION
403
Introduction 403
First Class of Solutions 403
Second Class of Solutions 404
Third Class of Solutions 406
Selection Criteria 409
Case Studies 409
PART IV
CHAPTER 16
16.1
317
What Are Harmonics? 379
Sources of Harmonics 384
Disturbances Caused by Harmonics 391
Principles of Harmonic Distortion Indications and Measurement
Frequency Spectrum and Harmonic Content 398
Standards and Recommendations 400
CHAPTER 15
15.1
15.2
15.3
15.4
15.5
15.6
297
Background 361
Shunt Compensation 365
Need for Shunt Compensation 366
An Example 368
How to Determine Compensation 370
CHAPTER 14
14.1
14.2
14.3
14.4
14.5
14.6
ELECTRIC POWER QUALITY
Voltage Quality 321
Methods of Voltage Drop Reduction 329
Voltage Sag Calculations 345
Estimation of Distribution Losses 356
CHAPTER 13
13.1
13.2
13.3
13.4
13.5
POWER QUALITY
Overview 297
Power Quality Problems 298
Cost of Power Quality 304
Solutions of Power Quality Problems 310
Solution Cycle for Power Quality Problems
CHAPTER 12
vii
MANAGEMENT AND AUTOMATION
DEMAND-SIDE MANAGEMENT AND ENERGY EFFICIENCY
Overview
431
431
viii
16.2
16.3
16.4
16.5
16.6
16.7
16.8
16.9
16.10
16.11
16.12
CONTENTS
DSM 432
Needs to Apply DSM 433
Means of DSM Programs 434
International Experience with DSM 437
Potential for DSM Application 438
The DSM Planning Process 439
Expected Benefits of Managing Demand 444
Energy Efficiency 444
Scenarios Used for Energy-Efficiency Application
Economic Benefits of Energy Efficiency 445
Application of Efficient Technology 445
CHAPTER 17
17.1
17.2
17.3
17.4
17.5
17.6
Introduction 465
Definitions 469
SCADA Components 470
SCADA Systems Architectures
SCADA Applications 480
SCADA and Grid Modernization
PART V
CHAPTER 18
18.1
18.2
18.3
473
484
DISTRIBUTED ENERGY RESOURCES
AND MICROGRIDS
DISTRIBUTED GENERATION
ELECTRICAL ENERGY STORAGE
Introduction 535
Electrical Energy Storage 535
Role of Electrical Energy Storage
Types of EES Systems 540
Energy Storage Application 550
CHAPTER 20
20.1
20.2
20.3
20.4
20.5
20.6
20.7
20.8
465
Power Systems and Distributed Generation
Performance of Distributed Generators 493
Case Study 518
CHAPTER 19
19.1
19.2
19.3
19.4
19.5
SCADA SYSTEMS
445
489
535
538
MICROGRIDS AND SMART GRIDS
Background 553
MG Benefits 555
MG Operation 556
Challenges 556
Handling the Challenges 557
Control Methodology 558
Case Study 560
Protection for MGs 570
489
553
CONTENTS
20.9
20.10
Concluding Remarks on MGs
Smart Grids 572
ix
572
APPENDIX A
DATA OF MICROGRID COMPONENTS
581
APPENDIX B
MATLAB SIMULINK MODELS
583
REFERENCES
589
INDEX
601
PREFACE
T
HANKS TO THE VERY GOOD response received by the first edition
of this book, the authors were encouraged to revise and prepare a second edition.
In taking advantage of this opportunity, the first edition has been thoroughly revised
from the perspectives of
r having a critical look at the organization and structure of the first edition, and
r the inclusion of new developments that have taken place since the first edition
was prepared.
Although the basic objective of the book remains the same as described in the
preface to the first edition and the material is still grouped in five parts, the original
edition had 14 chapters, whereas the new edition has 20 chapters. Some of the new
chapters are the result of re-arrangement of the material in the original book, while
the rest contain new material. A brief description of the five parts highlighting the
changes is given in what follows.
PART I: FUNDAMENTAL CONCEPTS
The background and power system structure, in addition to the layout of the distribution system for both small and large distribution systems, is presented as an introduction in Chapter 1. The fundamental concepts of distribution systems are now the
subject of Chapters 2 and 3. The duties of distribution engineers including the factors
affecting the planning process are introduced here. It is aimed at identifying the key
steps in planning. Examples of structures used in distribution systems at medium and
low voltages are presented.
Definitions of load forecast terms and different methods of estimating the
demand forecast with application examples are now explained in Chapter 4.
PART II: PROTECTION AND SWITCHGEAR
Earthing, protection schemes and distribution switchgear are included in this part.
Various methods of earthing, as the protection system is based on it, are explained
in Chapter 5. Computation of short-circuit current, on which the design of protection
is based, is presented in Chapter 6. General description of the types of protection
schemes in distribution systems is now split and is presented in Chapters 7 and 8.
xi
xii
PREFACE
Details about switchgear devices and switchgear installation, including the
major factors affecting the design of switchboards, have also been reorganized in
Chapters 9 and 10, respectively.
PART III: POWER QUALITY
The key elements of quality of power supply (voltage quality, power factor and harmonics) and means of their improvement are now explained in Chapters 11 through
15 with relatively minor revisions to the material in the original edition.
PART IV: MANAGEMENT AND AUTOMATION
Reliability, economics, investment aspects and methodologies applied to improve the
performance of the distribution systems are explained in Chapter 16 by applying
demand-side management and energy-efficiency policies.
The difference between system automation and monitoring, using supervisory
control and data acquisition (SCADA) systems, and the conditions of using various
architectures are given in Chapter 17. In addition, the role of SCADA to modernize
the distribution system to become a smart grid is illustrated.
PART V: DISTRIBUTED ENERGY RESOURCES AND
MICROGRIDS
Various types of distributed energy sources and the corresponding effect of integrating
these sources with the distribution system are described in Chapter 18.
Energy storage systems are required to meet the intermittency of the power
source when using solar or wind sources and to provide added benefits such as
improved control, power quality, dynamic and transient stability, reliability and satisfactory operation. Various types of energy storage systems that can be used for this
purpose are discussed in Chapter 19.
The integration of distributed generation, energy storage systems and consumption into one system, commonly referred to as a microgrid, in addition to the recent
trend to modernize it to become a smart grid, is illustrated in Chapter 20.
Electric power distribution systems cover a broad spectrum of topics. To keep
the overall length of the book within a reasonable limit, many of these topics are, per
force, not covered in depth. However, all material is supported by an extensive list
of references from which the interested reader can get more details for an in-depth
study.
Abdelhay A. Sallam
Om P. Malik
ACKNOWLEDGMENTS
N
O WORK OF ANY significance can be accomplished without the help
received from many sources. In that respect, this book is no exception. The authors
are grateful for the invaluable help received from many sources and wish to express
their gratitude to the following, in particular, without whose help it would not have
been possible to put this book together:
r Mr. Hany Shaltoot of Schneider-Electric, Egypt, for providing access to a number of relevant articles and company practices relating to the distribution systems. He also helped with obtaining permission from Square-D to include in
the book information on AccuSine® products.
r Square-D North America for permission to include the AccuSine® product
photos.
r Technical and Sales staff members of ABB-Egypt for making available manuals
describing the company practices and a number of illustrations included in the
book with permission.
r Dr. Azza Eldesoky for the information on load forecasting that is included in
the book and Dr. Ahmed Daoud for editing some of the illustrations.
r Dr. Tamer Melik, Optimal Technologies (Canada) Inc., for making available
the report on which a part of the material in Chapter 16 is based.
r European Commission, Community Research-Smart Grids technology platform for making available the report on which a part of the material in Chapter 20 is based.
In addition, help has been received from a number of other sources to which
the authors are indebted and wish to acknowledge and express their sincere thanks.
All this work requires the moral support of the families, and we wish to recognize that with our sincere appreciation. We dedicate this book:
To our wives,
Hanzada Sallam and Margareta Malik
A. A. S.
O. P. M.
xiii