电工技术学报2025，Vol.40Issue(15)：4860-4873,14.DOI:10.19595/j.cnki.1000-6753.tces.241340
不依赖同步对时的配电网接地故障双端行波测距方法及其误差分析
A Double-Terminal Traveling Wave Grounding Fault Location Scheme in Distribution Networks Independent of Time Synchronization and Its Error Analysis
摘要
Abstract
The distribution network is at the end of the power system,with a high probability of line faults,among which single-phase ground faults account for over 80%.To reduce the burden of manual line inspections and achieve rapid fault restoration in the distribution network,accurate localization of single-phase ground faults has been a long-standing research focus.However,the distribution network line is short,and the traveling wave process is extremely brief.Even with known fault branch segments,achieving precise localization of single-phase grounding faults remains challenging.Existing fault location algorithms often rely on zero-modal components,but the instability and difficulty in estimating the zero-modal wave velocity introduce significant errors in the location results.To address these issues,this paper proposes a single-phase grounding fault location method that combines the advantages of traditional single-and double-terminal methods,while eliminating the dependence on zero-modal wave velocity estimation and synchronization between terminals. Firstly,mathematical calculations of the on-site modal time difference are performed based on the modal wave velocity difference,which is then used to characterize the fault location.Variational mode decomposition(VMD)and the Teager energy operator(TEO)are applied to separately calibrate the first wavefronts of the aerial and zero-modal components on both sides of the fault.The modal time differences from both sides are then substituted into the fault location formula to calculate the fault distance.This approach eliminates the need for estimating the zero-modal wave velocity and avoids the challenges of synchronization and detecting reflected waves,effectively improving the accuracy of fault location.Simulation results based on PSCAD/EMTDC show that the proposed fault location method can quickly and reliably locate single-phase grounding faults in overhead distribution network lines,with an error of less than 100 meters across various fault scenarios,including different fault resistances,fault angles,fault locations,fault phases,and grounding methods of the neutral point.Testing has shown that the noise resistance threshold of the proposed algorithm is 40 dB.When the noise level in the measurement environment is high(SNR＜40 dB)and there is a certain proportion of impulse noise,the combination of multiple moving average filters(to suppress white noise)and median filters(to suppress impulse noise)ensures the accuracy of wavefront calibration.Results from dynamic simulation tests demonstrate that the proposed method can still accurately locate faults in high-noise environments,with a relative error of 1.26%. Finally,based on numerical analysis theory,error bounds are derived for both the single-and double-terminal methods based on the modulus wave speed difference,as well as for the proposed algorithm.The impact of wavefront calibration errors and zero-modal wave velocity estimation errors on the error bounds is explored,revealing the theoretical basis for the improved accuracy.Validation cases using the PSCAD/EMTDC simulation platform confirm these findings.The results indicate that,without considering synchronization errors,the proposed method and the double-terminal method achieve significantly higher accuracy than the algorithm based on the modal wave velocity difference.After accounting for synchronization errors,the proposed method demonstrates higher accuracy than the double-terminal method.关键词
配电网/单相接地故障/故障测距/零模行波/误差限Key words
Distribution networks/single-phase grounding fault/fault location/zero-modal traveling wave/error bounds分类
信息技术与安全科学引用本文复制引用
郑雨霖,郭谋发,陈方旭,林佳壕..不依赖同步对时的配电网接地故障双端行波测距方法及其误差分析[J].电工技术学报,2025,40(15):4860-4873,14.基金项目
国家自然科学基金资助项目(51677030). （51677030）
