Fault location of three-core power distribution cables based on lump-parameter model considering conductor couplings

Due to the poor working conditions, the three-core distribution cables are prone to faults. Since most of the cables are laid underground, accurate fault location is difficult. Considering the couplings between the earth screen and core conductors, a lump-parameter model of the three-core cable is constructed in this paper. Through the steady-state circuit analysis, a method for identifying and locating a fault in the three-core cable is proposed. In the method, the information of the grounding line current, core current and voltage phasors at both terminals in normal operation are firstly used to compensate the synchronous measurement error. Then, the fault current is derived by the phase-corrected phasors in fault condition to identify the fault conductor. Finally, the accurate fault distance is computed by employing the fault voltage continuity criterion. A three-core distribution cable model is created by RTDS and various fault simulations are conducted. The results demonstrate the effectiveness of the method under different fault conditions.