A novel fault location and recognition method for low voltage active distribution network

Abstract

As more and more DGs plugged into low voltage side of the distribution network, the low voltage distribution network has been changed to active distribution network. Bidirectional power flow and uncertainty of DGs' output cause the conventional fault location methods to be inapplicable in active distribution network for malfunction and miss trip, which makes the fault location in low voltage active distribution network an urgent problem. In order to solve this problem, a novel fault location and recognition method for low voltage active distribution network which needs 3-phase currents measurement only is proposed in this paper. In the proposed method, a low voltage active distribution network is installed with the measurement and data process units for current measurement and data process at nodes and a control center for fault location and recognition. By the division of the low voltage active distribution network into several two-terminal sections without branch, the fault location (inside/outside the section) with fault-phase selection can be determined by the calculation of A, B and C phase current phase-angle differences of each section and the fault type can be identified by judging the amplitudes of zero-sequence node currents at both ends of every fault section. Simulation verification of the proposed method has been carried out by MATLAB/Simulink, the simulation results indicate that fault in low voltage active distribution network can be located and recognized accurately by the proposed method with fast speed and self-adaption.