Fault Location Algorithm in Distribution Networks Considering Distributed Capacitive Current

Abstract

In recent years, with the expansion of urban scale and construction of energy infrastructure, more cities construct underground cables to replace overhead lines from the perspective of environment and safety. Thus, more distributed capacitive current flows back to distribution networks under fault conditions and affects the accuracy of fault locating. This paper proposes an iterative modification method of capacitive current to decrease the uncertainty of complex equations with micro synchronous phasor measurement unit (μPMU) data. Firstly, the initial fault location is calculated by using phasor measurement data without the shunt effect of grounding capacitance. Then, the capacitive current is estimated by the initial fault location distance, and the location result is modified by an iterative strategy. Finally, after iteration modification, a more accurate real number solution for complex equations can be obtained for complicated distribution networks with the uncertain capacitive current. The simulation results of a real underground distribution network and a modified IEEE 33 node test feeder in MATLAB/Simulink show that the proposed algorithm has higher accuracy than the traditional methods which do not have the iterative modification method of capacitive current under different fault locations, fault resistances, fault types and the neutral point grounding modes.