Zone Selective Protection System with Multiple Power Sources

Abstract

In the power system with multiple power sources, the fault current direction is not fixed. Therefore, the conventional ZSI protection is not suitable. Furthermore, the ZSI protection with fault current direction judgment function is required. In this paper, the R, L property based fault current direction judgment method is proposed. This method is verified based on the simulation and test result. The validation shows this method can correctly judge the fault current direction within shorter time than state of art method.