Performance comparison of current differential protection scheme based on symmetrical components

This paper presents the extended study on current differential protection schemes based on symmetrical components. The principles of the protection schemes are analyzed firstly. Their performances are evaluated on a typical 500 kV power transmission line system model using EMTP. Extensive simulation studies are presented under various system and fault conditions, such as variations in system load currents, fault resistances, fault location and fault types. Comprehensive comparison based on theoretic analysis and extensive simulation shows that negative-sequence current differential protection provides the best performance.