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Teaching Protective Relaying Concepts and Testing Methods

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2016 ASEE Annual Conference & Exposition


New Orleans, Louisiana

Publication Date

June 26, 2016

Start Date

June 26, 2016

End Date

August 28, 2016





Conference Session

Assessment, Course, and Curricular Development

Tagged Division

Energy Conversion and Conservation

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Glenn T. Wrate P.E. Northern Michigan University

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Glenn T. Wrate received his B.S.E.E. and M.S.E.E. from Michigan Technological University (MTU) in 1984 and 1986, respectively. While attending MTU, he worked for Bechtel Power Corporation on the Belle River and Midland power generating stations. After graduating MTU, he worked for the Los Angeles Department of Water and Power from 1986 to 1992, primarily in the Special Studies and High Voltage DC (HVDC) Stations Group. He returned to MTU in 1992 to pursue a Ph.D. in Electrical Engineering. While completing his research he worked in the relay testing group at Northern States Power Company in Minneapolis.
After obtaining his Ph.D., Glenn accepted an appointment as an Assistant Professor in the Electrical Engineering and Computer Science department at the Milwaukee School of Engineering (MSOE). In 1999 he was promoted to Associate Professor, in 2001 he won the Falk Engineering Educator Award and was promoted to head the Master of Science in Engineering (MSE) program. He received the Karl O. Werwath Engineering Research Award in 2003. In 2004 he moved from the MSE program to take over the Electrical Engineering program. After guiding the program through accreditation, he stepped down in 2007.
Dr. Wrate has now returned to his boyhood home and is teaching at Northern Michigan University. He is a member of HKN and IEEE, a Registered Professional Engineer in California, and is a past chair of the Energy Conversion and Conservation Division of ASEE.

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This paper covers problems inherent in teaching electrical power system protective relaying concepts and testing methods at the associate degree level in an electrical engineering technology program. In many cases, these problems are also seen at the baccalaureate level in both electrical engineering and electrical engineering technology. The first, and most difficult obstacle is symmetrical components. The mathematics behind symmetrical components involve complex numbers and linear algebra. While the students are exposed to complex numbers in their AC analysis course and, if required by their program, their electrical machinery course, most of the students have not had a linear algebra course. Another obstacle is power system stability. At best they may have a classical controls and/or dynamics course. This is why in most cases protective relaying is taught at the graduate level or via industrial seminars. Without a background in protective relaying concepts, the testing of the protective relay becomes very prescriptive. The student only learns the specific steps outlined by the relay manufacturer, or in some cases the textbook author, to determine if the relay performed one function correctly. Most utilities and electrical power system operators need protective relay technicians that understand the electrical power system and how the protective relays function to protect the system in the case of abnormal operating conditions. Simply knowing the output X was set when input Y reached a certain level is not sufficient. The methods used to cover protection of generators, transformers, transmission lines, and busses are discussed. The level of detail in symmetrical components: how they are derived, how they can be recombined to form phase quantities; along with what are the characteristics of the different sequence values, and what sequence quantities are associated with the different fault types are covered. Finally, zones of protection, communication between protective relays, and the subsequent effect on system integrity are also discussed.

Wrate, G. T. (2016, June), Teaching Protective Relaying Concepts and Testing Methods Paper presented at 2016 ASEE Annual Conference & Exposition, New Orleans, Louisiana. 10.18260/p.26048

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