Digital Relays

Power system protection is a practical area that requires extensive knowledge and experience. The organized structure, succinct illustration, and detailed programming examples provided in this book will benefit all levels of readers, including graduate students who are studying courses in electric power systems, as well as engineers who are working in electric utility companies, relay vendors, and consulting firms. - Abstruse principles and terminologies of relay functions and devices are demystified with 87 succinct illustrations. - Each chapter is provided with a summary of key points and a reference list that precisely guides readers to pertinent publications for further details. - Eleven representative examples with specific industry backgrounds are thoroughly illustrated. Twelve problems are provided in key chapters to facilitate readers to establish a comprehensive understanding of relay functions.

Hangtian Lei is an Associate Professor in the Department of Electrical and Computer Engineering at the University of Idaho, Moscow, Idaho, USA, where he has been working since 2017. He earned a BE degree in electrical engineering at Huazhong University of Science and Technology, Wuhan, China, and a PhD degree in electrical engineering at Texas A&M University, College Station, Texas, USA. His teaching and research interests include power system protection, power system reliability, and power system planning. He is a senior member of IEEE. Brian K. Johnson is a University Distinguished Professor and the Schweitzer Engineering Laboratories (SEL) Endowed Chair in Power Engineering in the Department of Electrical and Computer Engineering at the University of Idaho, Moscow, Idaho, USA. He earned his BS, MS, and PhD degrees in electrical engineering at the University of Wisconsin-Madison, Madison, Wisconsin, USA. He has been working at the University of Idaho for over 30 years, where he was the chair of the Department of Electrical and Computer Engineering from 2006 to 2012. His teaching and research interests include power system protection, HVDC transmission, and applications of power electronics in power systems. He is active with the IEEE Power and Energy Society, where he was the chair of the Power and Energy Education Committee from 2014 to 2015 and of the IEEE HVDC and FACTS subcommittee from 2018 to 2020. He is currently a member of the editorial board for IEEE Power and Energy Magazine. He is a senior member of IEEE.

1. Introduction. 2. Instrument Transformers. 3. Modeling Relay Functions Using MATLAB. 4. Overcurrent Protection. 5. Directional Elements. 6. Distance Protection. 7. Communication-Aided Protection Schemes. 8. Power Swing Blocking and Out-of-Step Tripping. 9. Differential Protection. 10. Time-Domain Protection.