A lengthways-comparison scheme to detect single phase fault in non-solid grounded network with feeder automation

Single-phase fault detection in non-solid grounded medium voltage network (i.e. isolated or a Peterson coil compensated) is a headachy problem. Nevertheless, situation is changing when a distribution automation system(DAS) is available. In this paper a new single phase ground fault detection technique named lengthways-comparison scheme is present. This scheme is feeder-object-oriented, and the FTU which located in a feeder can communicate with its neighbors. The negative current element is obtained by the synthesis negative sequence vector arithmetic (SNSV). Based on distributed FTU, the delta of SNSV current is used to detect a single grounded fault. The new scheme can be realized in a distribution automation system, and all the conclusions are verified by EMTP simulation, the results are exciting.