End-to-end relay testing using GPS-synchronized secondary injection

Digital signal processors and high-speed operating systems have revolutionized not only protective relays, but protective relay testing as well. Modern microprocessor-based relay test sets, combined with personal computers and GPS satellite receivers have provided the means to dynamically test relay protection schemes end-to-end. This paper describes the test system, test preparation, and test execution. Examples of end-to-end test applications are discussed.