基于高频分量的高压直流输电线路单端保护方法

Single-ended Protection Method for HVDC Transmission Line Based on High Frequency Component

输电线路是高压直流输电系统中故障率最高的元件。针对现有输电线路行波保护耐过渡电阻能力差,存在难以识别区内高阻故障和远端区外金属性故障的问题,提出了一种高压直流输电线路单端保护方法。基于高压直流输电系统拓扑,分析了高压直流输电线路区内和区外故障电流的特征,从而利用小波变换提取高频分量电流构建保护方法。仿真结果表明,该方法不受过渡电阻、故障距离影响,保护可靠性高。

Transmission line has the highest failure rate in HVDC system.In view of the poor performance to transition resistance of the existing traveling wave protection of transmission line,it is difficult to identify the high resistance internal fault and the low resistance external fault,a single-ended protection method for HVDC transmission line is proposed.Based on the topology of HVDC transmission system,the characteristics of internal and external fault current are analyzed,the high frequency component current is extracted by wavelet transform,and the protection method is constructed.The simulation results show that the proposed method has high protection reliability,and cannot be affected by the transition resistance and fault distance.