Analysis on Maloperation of 500 kV Station Transformer Protection in UHV Converter Station

This paper analyzes a incorrect protection operation that the secondary current circuit short-circuit of the 500 kV station transformer protection in an UHV converter station. By combining fault recording waveform diagrams and protection circuit inspection, the causes of incorrect protection operation were analyzed, reasoned, and verified. The fault point in the secondary current circuit was identified. The corresponding advice of the parameter setting put forward in this paper.