Cover Page





images

ELECTRIC POWER SYSTEM BASICS FOR THE NONELECTRICAL PROFESSIONAL

SECOND EDITION



STEVEN W. BLUME









Wiley Logo

PREFACE

ABOUT THE BOOK

This book is intended to give nonelectrical professionals a fundamental understanding of large interconnected electrical power systems, better known as the “Power Grid” with regard to terminology, electrical concepts, design considerations, construction practices, industry standards, control room operations for both normal and emergency conditions, maintenance, consumption, telecommunications, and safety. Several practical examples, photographs, drawings, and illustrations are provided to help the reader gain a fundamental understanding of electric power systems. The goal of this book is to have the nonelectrical professional come away with an in-depth understanding of how power systems work from electrical generation to household wiring and consumption through connected appliances.

This book starts with terminology and basic electrical concepts used in the industry then progresses through generation, transmission, and distribution of electrical power. The reader is exposed to all the important aspects of an interconnected power system. Other topics discussed include energy management, conservation of electrical energy, consumption characteristics, and regulatory aspects to help readers understand modern electric power systems in order to effectively communicate with seasoned engineers, equipment manufacturers, field personnel, regulatory officials, lobbyists, politicians, lawyers, and others working in the electrical industry.

Please note that some sections within most chapters elaborate on certain concepts by providing additional details or background. These sections are marked “optional supplementary reading” and maybe skipped without losing value to the intent of this book.

This Second Edition provides updates to renewable energy (solar and wind primarily), equipment photo updates, updates in regulatory issues, new measures taken to improve system reliability, and more on smart technologies used in the power grid system.

ABOUT THE AUTHOR

The author, Steven W. Blume, is a registered professional engineer with a master's degree in electrical engineering and over 40 years’ experience that covers all aspects of this book. Further, he has been teaching electric power system basics to nonelectrical professionals for over 25 years. His combined knowledge, experience, and ability to explain complex subjects in simple-to-understand terms present this book to those interested in gaining a fundamental understanding of electric power systems. Additional training materials are available to the reader such as online courses, instructor-led courses, private custom courses, and tour oriented courses. Visit www.aptc.edu. Blume is available at swblume@gmail.com

CHAPTER SUMMARIES

A brief overview of each chapter is presented below. Knowing where and when to expect specific topics and knowing how the information is organized in this book will help the reader comprehend the material easier. The language used in this book reflects actual industry terminology.

Chapter 1: System Overview, Terminology, and Basic Concepts

The book starts out with a brief yet informative discussion of the history that led to the power systems we know today. Then a system overview diagram is presented with brief discussions of the major divisions within an electric power system. Basic definitions and common terminology are then discussed such as voltage, current, power, and energy. Fundamental concepts such as direct and alternating current (i.e., dc and ac), frequency, single-phase and three-phase, types of loads, and power system efficiency are discussed to set the stage for more advanced learning.

How electrical generators produce electricity is also introduced in this chapter. The physical laws and concepts presented in this chapter serve as the foundation of all electric power systems.

Some very basic electrical formulas are presented in this chapter and at times elsewhere in the book. This is done intentionally to help explain terminology and concepts associated with electric power systems. The reader should not be intimidated nor concerned about the math, it is meant to describe and explain relationships.

Chapter 2: Generation

Basic concepts of the various electrical generation sources or power plants are presented in this chapter. These concepts include sub-systems that differentiate the plants regarding natural resources, spinning or non-spinning rotors, operational characteristics, environmental effects, and overall efficiencies.

The reader becomes more knowledgeable with the various aspects of electrical generation, the different prime movers used to rotate generator shafts and the basic building blocks that make up the various power plants. The prime movers discussed include steam, hydro, and wind turbines. Some of the non-rotating electric energy sources are also discussed in this chapter such as solar photovoltaic and biopower systems. The growth in renewable energy and its application to power grid operations are discussed.

The major equipment components or sub-systems associated with each power plant type are discussed such as boilers, cooling towers, boiler feed pumps, high- and low-pressure systems. The reader gains a basic understanding of power plant fundamentals as they read through this chapter.

Chapter 3: Transmission Lines

The reasons for using very high voltage power lines compared to low-voltage power lines are explained in this chapter. The fundamental components of transmission lines such as conductors, insulators, air gaps, and shielding are discussed. Direct current (dc) transmission and alternating current (ac) transmission lines are compared along with underground versus overhead. The reader will come away with a good understanding of transmission line design parameters and the benefits of using high-voltage transmission for efficient transport of electrical power.

Chapter 4: Substations

This chapter covers the equipment found in substations that transforms very high voltage electrical energy transported from generation facilities into a more useable form of electrical energy for distribution and consumption. The equipment themselves (i.e., transformers, regulators, circuit breakers, and disconnect switches) and their relationship to system protection, maintenance operations, and system control are discussed in this chapter. This chapter also includes discussions on new digital substation equipment being used to help modernize operations and reliability.

Chapter 5: Distribution

This chapter describes how primary distribution systems, both overhead and underground, are designed, operated, and used to serve residential, commercial, and industrial consumers. The distribution system between the substation and the consumer's demarcation point (i.e., service entrance equipment) is the focus. Overhead and underground line configurations, voltage classifications, and common equipment used in distribution systems are covered. The reader will learn how distribution systems are designed and built to provide reliable electrical power to the end users.

This chapter focuses on distribution systems in general; the modernization of distribution systems such as distribution automation, intelligent electronic devices, outage management, and customer information systems are discussed in Chapter 9.

Chapter 6: Consumption

The equipment located between the customer service entrance (i.e., demarcation point) and the wiring to the consumer's actual load devices are discussed in this chapter. The use of emergency generators and uninterruptible power supply (UPS) systems to enhance reliable power service are discussed along with their operating issues. Smart meters, service reliability indicators, common problems, and solutions associated with large power consumers are all covered in this chapter.

Chapter 7: System Protection

The difference between “system protection” and “personal protection” (i.e., safety) is explained first. Then this chapter is devoted to “system protection” and how electric power systems are protected against equipment failures, faults on power lines, lightning strikes, inadvertent operations, and other events that cause system disturbances. “Personal protection” is discussed later in chapter 10.

Reliable service is dependent upon properly designed and periodically tested protective relay systems. These systems, and their protective relays, are explained for transmission and distribution lines, substations, and generator units. The reader learns how the entire electric power system is designed to protect itself from power faults, lightning strikes, and to minimize the impact of major system disturbances.

Chapter 8: Interconnected Power Systems

This chapter starts out with a discussion of the four major power grids in North America and how these grids are territorially divided, operated, controlled, and regulated. The emphasis is to explain how the individual power companies are interconnected to improve the overall performance, reliability, stability, and security of the entire power grid. Other topics discussed include generation-load balance, resource planning, and operational limitations under normal and emergency conditions. Last, the concepts of rolling blackouts, brownouts, load shedding, and other service reliability issues and the methods used to minimize outages are discussed.

Chapter 9: System Control Centers and Telecommunications

System control centers are extremely important in the day-to-day operation of electric power systems. This chapter explains how system control center operators monitor and control equipment remotely. The advanced computer programs and telecommunications systems used to control power equipment remotely in substations, on power lines, and the actual consumer are discussed. These tools enable power system operators to economically dispatch power, meet system energy demands, control equipment during normal and during emergency conditions. The explanation and use of SCADA (Supervisory Control and Data Acquisition) and EMS (Energy Management Systems) are included in this chapter.

The functionality and benefits of the various types of communications systems used to connect system control centers with remote terminal units are discussed. These telecommunication systems include fiber optics, microwave, power line carrier, radio, and copper wireline circuits. The methods used to provide high speed protective relaying, customer service call centers, and digital data/voice/video communications services are all discussed in a fundamental manner.

The modernization of system control center tools such as synchrophasors and wide area monitoring systems to improve system security and reliability are discussed in this chapter. Distribution control and system modernization are also discussed in this chapter.

Chapter 10: Personal Protection (Safety)

The book concludes with a chapter devoted to electrical safety: personal protection and safe working procedures in and around high-voltage electric power systems. Personal protective equipment such as rubber insulation products and the equipment necessary for effective grounding are described. Common safety procedures and proper safety methods are discussed, including “equipotential grounding.” The understanding of “ground potential rise,” “touch potential,” and “step potential” adds a strong message to the reader as to the proper precautions needed when being around high-voltage power lines, substations, and even around the home.

This chapter includes a discussion around the very important issue of arc flash safety. The discussion includes governmental rules and regulations, proper safety procedures, responsibilities, and the special clothing needed to protect oneself from the hazard of arc flash should equipment unexpectedly explode or arc causing dangerous heat exposure when events like this are in close proximity to workers.

The last item discussed in this book is electrical safety around the home. Albeit high voltage is dangerous, normal residential voltage around the home is lethal too and safety around the home is also a very important topic to cover.

In summary, the purpose of this book is to give readers a basic overview of how electric power systems work, followed by a chapter on electrical safety around high-voltage equipment and the home.

ACKNOWLEDGMENTS

I WOULD personally like to thank several people who have contributed to the success of my career and the success of this book. To my wife Maureen who has been supporting me for well over 40 years. Thank you for your guidance, understanding, encouragement, and so much more. Thank you Michele Wynne; your enthusiasm, organizational skills, and creative ideas are greatly appreciated. Thank you Bill Ackerman; you are a great go-to person for technical answers, courseware development, and you always display professionalism and responsibility. Thank you John McDonald; your encouragement, vision, and recognition are greatly appreciated. I would also like to thank all of those who reviewed my final draft manuscript and provided professional suggestions that further enhanced this book for your benefit.

Steven W. Blume