特高压直流输电线路接地极线路高阻故障测距方法研究

直流接地极线路不同于直流输电线路,其在正常运行下,电压电流的值均很小,且极址点是通过阻值很小的过渡电阻接地,因此接地极线路精确定位是故障测距的难点。理论分析和仿真表明,当接地极线路发生接地故障,且接地点电阻大于或等于极址电阻时,流入故障点的电流很小,利用沿线电压分布推导得到的故障点电压不再是电压在线路上分布的最小值,而极址点电压是沿线电压分布的最小值。因此根据故障点电压相等来构造测距函数的测距原理存在不足之处。利用极址点电压相等构造测距函数,提出一种基于故障录波数据的耐受高阻接地的直流接地极线路故障测距新方法。大量仿真表明,该算法可以实现接地极线路的精确定位,对采样率要求不高,便于工程实际运用。

Research on fault location algorithm for HVDC electrode line high impedance fault

HVDC grounding electrode line is different from normal DC transmission line. Normally, the average of voltage and current are small, beside the address electrode resistor is small, so that make the DC grounding electrode lines fault location difficult. Many simulations show when grounding electrode line is fault and the ground resistance is greater than or equal to the address electrode resistor, then little current flows into fault point. The fault point voltage is not the minimum for the distribution of voltage along the line but the address electrode voltage. So the fault location algorithm based on the equal of fault point voltage has greater error. A new fault location method which can withstand high impedance based on voltage equal at pole point is presented. Many simulations show that the algorithm can accurate position the electrode line.