摘要
基于故障暂态量分布特征的线路保护不受系统运行方式、工频振荡等影响,对故障的判别更加快速、准确。线路发生区外故障时,高频成分在经过线路边界时发生明显的透反射效应,造成能量上的损耗,故障电流中高频含量低;而区内故障则不存在这个现象,故障电流中高频含量高。基于线路故障时产生的宽带高频暂态电流分量,利用D2小波能量谱实现故障的快速检测,并构造了小波能量熵量化描述高频暂态电流成分的能量分布,实现区内、外故障的判别。在PSCAD/EMTDC中搭建仿真模型,结果表明:该算法能很好地进行线路故障的快速检测及区内、外故障的判别,受故障类型、故障位置等因素的影响小。
The line protection based on fault transient distribution characteristics is not affected by system operation mode,power frequency oscillation and other factors,which has faster and more accurate fault identification. When the external fault occurs,the high frequency component has obvious reflection effect while passing through the line boundary,which results in energy loss and low content of high frequency in fault current. However,there is no such problem in internal fault,the content of high frequency in fault current is high. According to the wideband high frequency transient current component generated by line fault,this paper adopted the D2 wavelet energy spectrum to detect the fault quickly and constructed the wavelet energy entropy to obtain quantized description of energy distribution of the high frequency transient current component,thus distinguishing the internal and external fault. A simulation model was established on PSCAD/EMTDC,and the results show that the algorithm has good performance in detecting line faults and distinguishing internal and external faults and is almost free from the influence of fault type,location and other factors.
引文
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