基于Kaiser窗滤波的高压直流输电线路突变量功率保护

HVDC Line Protection Based on the Mutant Power Through Kaiser Window

研究了一种反映突变量中直流分量的高压直流输电线路功率保护。为了获得突变量中的直流分量,分析了高压直流输电线路区内外故障时两端突变量电压和突变量电流的特征,利用Kaiser窗提取突变量电压和突变量电流中的直流分量,提出了基于同极线两端突变量功率极性比较的保护原理和基于突变量功率幅值的启动判据,并构造了利用突变量电压的故障极识别判据,设计了保护的动作方案。由于保护动作判据采用的是突变量功率中的直流分量,所以从本质上反映了直流线路的故障特征。理论分析和仿真结果表明,所提出的保护方案能够正确区分线路内外部故障,耐受过渡电阻能力强,且能够准确识别故障极线,适合作为高压直流输电线路的后备保护。

We studied a new HVDC line protection based on the DC component of mutant power.Moreover, by analyzing the characteristics of mutant voltage and mutant current at both ends of the HVDC transmission line with faults inside and outside the line, we used Kaiser window to extract the DC components. The line protection principle is based on polarities of the mutant power at the two ends of the same line. By comparing the mutant power magnitude with the threshold value, the start criterion for the line protection was presented. The identification criterion of the fault pole was used to calculate the mutant voltage. Finally, a complete line protection scheme was designed. Because the protection criterion applies the DC component of mutant power, the fault features are essentially reflected. Theoretical analysis and simulation results show that the protection scheme proposed by this paper can correctly distinguish internal faults between external faults with strong transition-resistance-tolerated ability, and can accurately identify the fault pole, so it is suitable for the HVDC line backup protection.