【摘要】 电压源换流器型高压直流输电VSC-HVDC系统大多采用地下电缆作为其输电线路,但由于地下电缆行波色散严重,导致在对长距离输电线路进行故障测距时,难以准确测量出故障行波的到达时刻。本文提出了一种基于双端故障信息的单端故障测距方法,即当故障距离小于总长度一半时,采用前端的故障行波进行测距;当故障距离大于总长度一半时,采用后端的故障行波进行测距。该法采用数学形态学算法,当获取故障行波后,用数学形态学梯度算法进行故障发生时刻的提取。采用PSCAD和MATLAB进行建模仿真和数据处理,仿真结果表明,该法测量准确度较高,400 km的电缆线路上,误差在总线路长度的0.5%以内。该法测距精确,所需设备少,且不受噪声和过渡电阻的影响。更多还原

【Abstract】 Voltage source converter-high voltage direct current transmission(VSC-HVDC)system mostly uses under-ground cables as its transmission lines,but the traveling wave on underground cable lines disperses seriously,whichleads to difficulty in measuring the arrival time of fault traveling waves when the transmission line is long. This paperpresents a single-ended fault location method based on two-terminal fault information:when the fault distance is lessthan half of the total length,the fault traveling wave at the front-end is used;when the fault distance is longer than halfof the total length,the fault traveling wave at the back-end is used. After the fault traveling wave is obtained,the timeof failure is extracted using morphological gradient algorithm. In this paper,PSCAD and MATLAB are used for simula-tion and data processing,respectively. Simulation results show that the measurement accuracy of this method is higher,i.e.,the error is within 0.5% of the total line length in the case of 400 km cable. This method is precise,and it requiresless equipment. Moreover,it is not affected by noise or transition resistors.更多还原