Real-time digital simulators in conjunction with current and voltage amplifiers offer an opportunity for detailed testing of modern microprocessor based relays in conditions as close to realistic as possible. Testing a digital line current differential protection system creates challenging problems as a number of communications-related test scenarios should be examined in combination with power system disturbances. This paper presents a methodology for testing 2- and 3-terminal line current differential systems. Sample test results and a number of recommendations for testing digital relays have been included. The Real-Time Digital Simulator (RTDS) and Communications Data Link Simulator (CDLS) were the testing tools used.
I. Voloh, B. Kasztenny and C. B. Campbell, "Testing line current differential relays using real-time digital simulators," 2001 IEEE/PES Transmission and Distribution Conference and Exposition. Developing New Perspectives (Cat. No.01CH37294), Atlanta, GA, USA, 2001, pp. 516-521 vol.1, doi: 10.1109/TDC.2001.971287.
KEYWORDS: power system protection, line differential relay, relay communications, real-time digital simulator, data link simulator