Centralized substation level protection for determination of faulty feeder in distribution network

This paper presents a novel approach to design of a centralized substation level protection aimed at determining the faulty feeder in a distribution network. In opposite to phase-to-ground faults in the transmission networks (HV), impedance of phase-to-ground fault-loops in MV distribution networks is usually high. From all of these reasons, detection of ground-fault and determination of a faulty feeder at a bus-bar with many outgoing feeders arises as serious problem. However, during the ground-fault the transient component which provides important information about the disturbance in the system appears. Such signals consist of different frequency components, which result from charging or discharging of the network capacitances. In this paper new approach which is based on checking a phase displacement between a fundamental frequency component of zero sequence current and a voltage directly after the fault inception is presented. Provided simulation experiments in ATP/EMTP software package confirm the effectiveness of the proposed technique for selection of a faulty feeder during phase-to-ground fault in different and under different fault scenarios-different fault inception angles, including random mechanism and high resistance faults.