利用零序电流全量Hough变换的配电网故障选线方法

A Novel Hough Transform Approach of Fault Line Selection in Distribution Networks Using Total Zero-sequence Current

对配电网单相接地故障电磁暂态仿真分析表明,故障馈线和健全馈线的零序电流全量起始阶段的整体变化趋势相反。基于此,提出应用Hough变换对零序电流起始阶段整体变化趋势进行变化方向检测的故障选线新方法。利用配电网故障后短时窗各馈线零序电流数据进行Hough变换,构造出零序电流全量起始阶段整体变化趋势的"整体"突变方向夹角。故障馈线零序电流全量起始阶段整体变化趋势突变方向与"整体"突变方向相反,健全馈线零序电流全量起始阶段整体变化趋势突变方向与"整体"突变方向相同。该方法原理简单,降低了对硬件采样速率的要求。大量仿真结果表明该方法准确、可靠。

The analysis of single-phase grounded fault in a distribution power system shows that the overall trends of the initial stage in zero-sequence current between the fault feeder and the sound feeder are opposite. Thus, a novel fault line selection approach employing the Hough transform to detect the overall trends of the initial stage in zero^sequenee current is proposed. The data of zero-sequence current after fault is transformed by utilizing the Hough transform, and then constructing an overall mutation direction angle of the overall trends of the initial stage in zero-sequence. The initial direction trend polarity of zero- sequence current of faulty line is different from the whole mutation polarity, while in non-fault line it is the same as the whole polarity of power frequency variation. The Hough transform based method is simple in theory and significantly relaxes the requirement of sampling rates. Substantial simulation results illustrate the method is accurate and reliable. This work is supported by National High Technology Research and Development Program of China （863 Program） （No. 2012AA050213）.