Cause Analysis and Improvement Measures about Excessive Zero-Sequence Current of 35 kV Quadruple-Circuit Transmission Lines on the Same Tower in a Photovoltaic Power Station
A photovoltaic power station in Guangxi is sent out by 35 kV quadruple-circuit transmission lines on the same tower.After the expansion and grid connection of the power station,zero-sequence overcurrent tripping accidents occurred many times,which seriously affected the power transmission of the power station.In this paper,the causes of zero-sequence overcurrent tripping are analyzed by combining theoretical analysis with numerical simulation,and the phase sequence optimization layout scheme is proposed.The effectiveness of the proposed scheme is verified by numerical simulation tools.The problems existing in the n-1 fault state of the quadruple-circuit transmission lines on the same tower are analyzed,and the suggestion of avoiding the misoperation of zero-sequence overcurrent protection is put forward.The results show that the tripping fault is caused by improper phase sequence arrangement of quadruple-circuit transmission lines on the same tower;The implementation of the optimization scheme can effectively solve the problem of zero-sequence overcurrent in the transmission line,The field measurement results are basically consistent with the simulation results,which verifies the correctness and effectiveness of the proposed optimization scheme.The research results can provide reference for the analysis and treatment of zero-sequence overcurrent problem of multi-circuit transmission lines on the same tower.
zero-sequence current35 kV transmission linequadruple-circuit transmission line on the same towerphase sequence arrangement
国家科技期刊平台
NSTL
万方数据
