Study on active distribution network protection based on short-time integral parameter of total harmonic distortion rate

The large-scale access of distributed generator (DG) in distribution network has increased the difficulty of traditional distribution network protection calibration, and experts and scholars have proposed a variety of solutions, but how to accurately identify and remove ground faults with large transition resistance is still a difficult problem. Therefore, this paper proposes a magnitude comparative protection principle based on the Total harmonic distortion (THD) short-time integration parameter, and the applicability of the proposed protection principle is verified by simulation using the PSCAD simulation platform. From the theoretical analysis and simulation verification, it can be seen that the protection principle has good sensitivity in recognizing various ground faults with large transition resistances, and also has good applicability to interphase faults, which provides a new scheme for improving the transition resistance capability of distribution network protection.