The AC transmission line fault near the LCC-HVDC inverter station might lead to commutation failure.And fault voltage and current waveforms would be distorted.It will have an adverse effect on the performance of fundamental power frequency phasor based distance protection.Firstly,the performance of traditional distance protection based on positive-sequence voltage polarization which is widely used in practice is analyzed.If the LCC-HVDC inverter station only has the single AC transmission outgoing line,distance protection based on positive-sequence voltage polarization would no longer be applicable.Then,based on the RL model of AC transmission line,a time domain distance protection based on waveform correlation coefficient is proposed.It is not affected by the nonlinear output characteristics of LCC-HVDC inverter station.To solve the fault direction identification problem near the exit area,the index of current distortion is defined to identify the fault direction.Finally,the proposed time domain distance protection is verified by the simulation results.
关键词
逆变站/交流线路/时域距离保护/波形相关系数/电流畸变程度
Key words
LCC-HVDC inverter station/AC transmission line/time domain distance protection/waveform correlation coefficient/degree of current distortion
维普
万方数据