电工技术学报2025，Vol.40Issue(15)：4845-4859,15.DOI:10.19595/j.cnki.1000-6753.tces.241234
基于矩阵变换与模态分析的电缆型配电网单相接地故障区段定位
Single-Phase Grounding Fault Section Location of the Distribution Cable Networks Based on Matrix Transformation and Mode Analysis
摘要
Abstract
Cables in urban distribution networks have advantages such as lightweight,high-temperature resistance,and high transmission power.However,over time,they can be affected by erosion,mechanical forces,and long-term overload operation,leading to insulation degradation and defects.Locating single-phase grounding faults in distribution networks is difficult due to the complex structure and short cable length.Furthermore,the existing decoupling methods for overhead lines and three-core cables are challenging to adapt. The complex structure of multi-conductor coupling in three-phase single core cables of distribution networks,which is easily affected by proximity and skin effects,and the weak and variable characteristics of single-phase grounding faults in practical applications,as well as the difficulty of precise fault location in complex distribution networks,have not been solved.Many scholars have conducted extensive research in recent years on the precise positioning problem of cable-type distribution networks.Further analysis has found that there are still two problems with existing fault positioning technologies:(1)The multi-conductor structure coupling of three-phase single-core cables in distribution networks is complex,and the electrical parameters are asymmetric,making it difficult to transplant existing decoupling methods.(2)The grid structure of a cable-type distribution network with multiple nodes and short branches makes the refraction and reflection of traveling waves more complex,requiring high hardware requirements for measurement devices and communication equipment,making it difficult to meet both reliability and economy simultaneously. This paper proposes a section location method based on single-core cable matrix transformation and fault characteristic modal analysis to address the problems of existing methods.Specifically,(1)Based on the complex coupling between the conductor and shielding layer of a single-core cable in the distribution network,a phase mode transformation method is proposed to achieve complete system decoupling under frequency conditions.(2)Analyze the transient fault characteristic changes and measurement feasibility of decoupled modal signals to screen fault characteristic modes reasonably.(3)A topology measurement point distribution matrix,a current alpha mode polarity matrix,and a final criterion matrix dominated by diagonal elements are constructed.The information exchange between matrices is utilized to achieve logical judgment,thereby reducing the number of measurement points and saving costs while achieving high-precision fault location.The simulation results show that this method can accurately position single-phase grounding faults under complex conditions and has advantages such as low computational complexity,small storage capacity,low time consumption,and high timeliness compared to existing methods.The following conclusions have been drawn through research:(1)A matrix transformation method is proposed for three-phase single-core cables to achieve complete decoupling of the cable system.(2)The voltage σ mode and current α mode can be used as fault characteristic modes before and after single-phase grounding faults.(3)By configuring measuring points based on the spatial location of the distribution network,accurate fault section positioning can be achieved while saving costs.(4)This method offers advantages in measuring point configuration,decoupling degree,and resistance to noise interference compared to existing methods.The criterion matrix has low computational complexity and high timeliness,with certain engineering values.关键词
完全解耦/特征模态/矩阵变换/单相接地故障/配电电缆Key words
Complete decoupling/characteristic mode/matrix transformation/single-phase grounding fault/distribution cables分类
信息技术与安全科学引用本文复制引用
王晓卫,王雪,王璐,范林慧,康乾坤..基于矩阵变换与模态分析的电缆型配电网单相接地故障区段定位[J].电工技术学报,2025,40(15):4845-4859,15.基金项目
国家自然科学基金资助项目(52177114,61403127). （52177114,61403127）
