CAJ | 학술논문

结合一起兴安直流线路因高阻接地故障引起的跳闸事故，通过对87DCLL逻辑的分析，对兴安直流线路纵差保护原理进行了改进。提出将87DCLL去掉“600 ms闭锁逻辑”，并基于仿真结果将保护延时调整至800 ms。仿真结果验证了所提措施不会导致87DCLL出现误动，并且在直流线路发生高阻抗接地故障时87DCLL能正确动作。
결합일기흥안직류선로인고조접지고장인기적도갑사고，통과대87DCLL라집적분석，대흥안직류선로종차보호원리진행료개진。제출장87DCLL거도“600 ms폐쇄라집”，병기우방진결과장보호연시조정지800 ms。방진결과험증료소제조시불회도치87DCLL출현오동，병차재직류선로발생고조항접지고장시87DCLL능정학동작。
Based on analysis of a tripping accident in Xing-An HVDC system due to high impedance ground fault and the logic of 87DCLL, this paper presents an improvement of the DC line longitudinal differential protection principle. It is proposed to remove the"600 ms blocking logic" from 87DCLL, and adjust the delay to 800 ms based on simulation results. Simulation results demenstrate that the proposed measures would not lead to 87DCLL malfunction, and 87DCLL can operate correctly when a high-impedance ground fault occurs in the DC line .