A single-phase matrix algorithm for fault location of two-phase earthing fault in distribution systems

When two-phase earthing fault occurs in different sections of a feeder in a distribution system, part of section switches may have two phase fault current flowing through and part of section switches may have one phase fault current flowing through. So, fault current characteristic of this kind of fault is different from that of interphase short circuit fault. Then the traditional matrix algorithm will not be able to solve the fault location problem of this kind of fault. In order to solve the fault location problem, a single-phase matrix algorithm is put forward. This kind of fault has two fault phases and each fault phase has one single-phase fault information matrix. By multiplying each single-phase fault information matrix with the network describing matrix of the fault feeder, the single-phase fault judgment matrix of corresponding fault phase is generated. Both fault positions can be found by corresponding single-phase fault judgment matrixes.