Assessing application features of protective relays and systems through automated testing using fault transients

This paper presents a new approach to assessing application features of protective relays. The approach utilizes a test methodology based on the use of transients. Application features of protective relays, such as the response time and trip selectivity, may be extremely important when investigating relay misoperations or when purchasing new relays. These features are not readily known or made available in the relay manuals. The paper provides examples of how the test methodology may be applied and what kind or results may be obtained. It also discusses the requirements for the test tools to be used. A discussion of the test tools features that may be needed as well as the ways the tools may be applied to perform testing is presented as well. Conclusions about the needs for suitable test tools are given at the end.