DYNAMIC TESTING OF FREQUENCY RELAYS

Frequency relays are often applied on power systems either to protect generation equipment or provide load shedding capabilities. Accurate s etting and operation of these relays is essential in the proper coordi nation of the power system equipment. Dynamic testing provides a metho d of assuring the proper operation of frequency relays. Along with thi s testing is a myriad of complexities and confusion. Dynamic tests are not always as straightforward as one might think, especially when the results are not as anticipated. The methods of testing, type of test equipment used, and the specific relay measuring techniques all play a significant role in the dynamic testing results. This paper discusses the intricacies of dynamic frequency testing along with the differenc es between test equipment and frequency relays and how these differenc es affect the testing results. A sampling of four frequency relays was tested (three solid-state devices and one electromechanical), each us ing four different test sets. Results of each will be discussed.