Analysis on Operation Characteristics of Ground Distance Protection for the Mixed Voltage Four Circuit Transmission Lines on the Same Tower

According to the structural feature that the phase to phase coupling of the mixed voltage non transposed four circuit transmission line on the same tower leads to parameter asymmetry, combined with the original data of Shuixiang-Wancheng transmission line, a line simulation model is built by PSCAD. On this basis, the effects of fault location, transition resistance and fault type on the performance of fault component impedance relay, quadrilateral characteristic distance relay and zero sequence reactance relay are analyzed and studied. The above research results can provide reference for the function configuration, setting calculation and engineering application of distance protection for complex lines on the same tower.