基于前后逐段逼近的含多分支配电网单相接地故障测距方法

A single-phase ground fault ranging method based on back-and-forth segment-by-segment approximation for distribution networks with multiple branches

随着配电网的发展,T接分支的大量接入使得配电网结构复杂,传统测距算法通常忽略分支,测距精度变低,研究含多分支配电网单相接地故障测距具有重要意义。为此,提出一种基于前后逐段逼近的含多分支配电网单相接地故障精确测距方法。首先,分析分布参数模型,根据零序电压、电流关系,提出故障区段判别系数,判别最小故障区段。其次,利用最小故障区段两端的零序电压、电流建立故障测距函数,采用梯度下降法求解精确故障点。最后,在PSCAD仿真平台上对所述方法进行验证。结果表明,所提方法可确定故障最小区段,精确计算出故障点,并具有较强的耐受过渡电阻能力,能较好适应高渗透率分布式电源的接入。

With the development of the distribution network,the large number of T-connected branches complicates the network structure.Traditional ranging algorithms often overlook the branches,resulting in decreased ranging accuracy.Researching the precise location of single-phase ground faults in distribution networks with multiple branches is therefore significant.To address this,an accurate single-phase ground fault ranging method based on back-and-forth segmentby-segment approximation for distribution networks with multiple branches is proposed.First,the distributed parameter model is analyzed.From the relationship between zero sequence voltage and current,a discriminant coefficient of fault section is proposed to determine the minimum fault section.Secondly,the fault location function is established by using the zero sequence voltage and current at both ends of the minimum fault section,and the gradient descent method is used to solve the accurate fault point.Finally,the proposed method is validated on the PSCAD simulation platform.The results demonstrate that the proposed method can identify the minimum fault section,accurately calculate the fault point,and exhibits strong resistance to transition resistance,making it well-suited for accommodating high-permeability distributed generation.