DC fault location in multi-terminal DC distribution network based on voltage similar triangle principle

Abstract

This paper presents a fault location method for multi-terminal DC distribution network based on voltage similar triangle principle. To estimate the fault location of DC lines, the concept of pseudo voltage is illustrated. In this method, the real voltage and pseudo voltage of two-terminal capacitors are formed into a similar triangle with the fault point voltage, and the fault location algorithm is established based on the principle of the similar triangle. This paper analyses the reasons of the location error affected by weak synchronization, and presents an effective solution. In addition, it is also considered the effects of the line distributed capacitance, noise, and arc fault on the location results. A four-terminal DC distribution network model built by PSCAD/EMTDC is considered as the test system. The simulation results show that the proposed method can locate the fault point quickly and has high accuracy. In addition, a small-scale hardware experiment platform also verifies the feasibility of the proposed method.