Transformer inrush mitigation using controlled switching of a 500-kV circuit breaker

Abstract

This paper presents post event analyses of three inrush events that caused relay misoperation. It then presents the results of an EMTP study that illustrates the degree to which different techniques can mitigate the transformer inrush transient and compares this to the predicted performance of closing resistors in an identical application. It demonstrates that controlled switching of a transformer adequately mitigates inrush transients.