Review of generation system overflux limiters and protection and consequences of incorrect settings

摘要

This paper presents a brief review of the coordination issues between the settings for generator automatic voltage regulator (AVR) overflux (V/Hz) limiters and monitors and the overflux protection relay settings. Recent blackouts have caused NERC (North American Electric Reliability Council) to develop standards for coordination of generator excitation control and protection [1–2] with the aim of improving overall system reliability. The paper considers some practical issues encountered when coordinating protection to ensure generators remain on-line whenever possible to support the power system whilst remaining within recommended limits to ensure maximum equipment lifetime. Consequence of incorrect overflux setting is presented.