A novel fault section location method for single pole to ground fault of DC distribution lines

Abstract

AbstractDirect‐current (DC) distribution lines are mostly underground cables, with the highest probability of single pole to ground fault among various faults. However, the topology of DC distribution networks is flexible and variable, and existing fault location technologies cannot achieve both high accuracy and good adaptability. A fault section location method for single pole to ground fault in DC distribution lines based on steady‐state zero‐mode current direction is proposed. First, a unified zero‐mode equivalent model for the DC distributed system in the non‐effectively grounded system is established. Then the directional difference in zero‐mode current between the fault and non‐fault sections in the zero‐mode network is fully explored when a single pole to ground fault occurs. Next, a fault section location criterion based on the direction of the steady‐state zero‐mode current is proposed to effectively identify the single‐pole grounded fault section. The feasibility of the proposed fault section location method under different fault conditions is verified based on the PSCAD/EMTDC software. In addition, the simulations show that the proposed method is suitable in the non‐effectively grounded system, and has low requirements for sampling frequency and data processing, with strong resistance to transition resistance.