Causes and Solutions for the Mal-operation of Differential Pressure Protection of Substation

Abstract

The capacitor compensation circuit of the traction substation is affected by high-harmonics and the differential voltage protection is frequently mal-operation, which causes serious disturbance to the railroad transportation order. In this paper, the effect of parasitic inductance of capacitor banks and the parameter characteristics under high harmonics are analyzed by establishing the high-frequency circuit structure of capacitor banks. Then, a fitting formula describing the differential voltage is established based on the measured data to describe the frequency variation characteristics of the differential voltage value. Finally, a solution to the problem of differential voltage protection mal-operation of capacitor banks is discussed, a Resistance-Capacitance filter circuit is designed, and the effectiveness is verified by simulation.