基于极点对称模态分解的配电网单相接地故障区段定位技术

Fault section location method for single-phase grounding fault in distribution network based on ESMD

配电网发生单相接地故障后,系统中将产生丰富的暂态电气量。利用故障点上游暂态零序电流幅值远大于故障点下游及正常线路的特征,提出一种基于暂态零序电流极点对称模态分解(ESMD)的配电网故障区段定位方法。基于实际配电网线路参数搭建典型缆-线混联仿真模型,对故障后暂态零序电流进行极点对称模态分解并构造相应的暂态能量函数,将构造所得的暂态能量函数作为评价各测点暂态零序电流幅值强弱的指标进行故障区段定位。仿真结果表明所提方法可有效提取故障特征,对各种故障工况适应性强,且各测点仅需上传1个暂态能量值,可有效降低通信要求、节约硬件投资成本。

Single-phase grounding fault in distribution network generates abundant electrical transient quantities in the system. Based on the characteristic that the magnitude of transient zero-sequence current at upstream of the fault point is much larger than that at the downstream of the fault point and normal line,the fault section location method based on ESMD(Extreme-point Symmetric Mode Decomposition) is proposed for distribution network. Based on line parameters of actual distribution network,a typical cable-line hybrid simulation model is established,with which,the transient zero-sequence current is decomposed by ESMD and the transient energy function is constructed. The tran-sient energy function is used as an index to evaluate the magnitude of the transient zero-sequence current of each measurement point for fault section location. The simulative results show that the proposed method can extract fault features effectively,and has strong adaptability to various fault conditions,and each measurement point only needs to upload one transient energy value,which can effectively reduce communication requirements and save hardware investment costs.