实验技术与管理2025，Vol.42Issue(7)：34-42,9.DOI:10.16791/j.cnki.sjg.2025.07.005
基于暂态零序功率特性的配电网单相接地故障选段实验设计
Experimental design for single-phase grounding fault section selection in distribution networks based on transient zero-sequence power characteristics
摘要
Abstract
[Objective]A single-phase grounding fault is the most frequent type of fault in distribution networks,and identifying the fault accurately and locating the fault section for the safe operation of power networks is crucial.However,because of small fault current,weak fault characteristics,and poor dispersion,the accuracy of fault location in engineering practice is low.In order to enhance the quality of experimental teaching,students'cognition of single-phase grounding fault in distribution networks,and their practical analytical skills,this paper presents an experimental design scheme for the resonant grounding fault segment in distribution networks.[Methods]First,the design method of the single-phase grounding fault experiment platform is described,including the components of the 10 kV true type experiment system and the hardware and software designs of the single-phase fault grounding current identification terminal to build a real experimental environment for the research.Second,the design scheme of the distribution network grounding fault section is proposed.After an in-depth analysis of the polarity differences between the transient zero-sequence signals in the healthy section and the faulty section,it is found that when transient zero-sequence power is directly calculated,misjudgment will occur because of the influence of arc suppression coil compensation and noise interference.However,some frequency band information of the zero-sequence power contains characteristic information that can effectively suppress the interference.Based on this,the transient zero-sequence power is decomposed by a wavelet packet algorithm,in which the frequency band with strong energy entropy can stably reflect the state characteristics of the line.Considering the randomness and uncertainty of the fault arc and the presence of field noise,the high-entropy characteristic frequency bands of each fault sample are not the same,and the number of characteristic frequency bands available for selection is large.Therefore,this paper further proposes a feature frequency band optimization method based on a genetic algorithm and wavelet packet energy entropy.In the offline stage,the genetic algorithm is used to screen the massive historical data and optimize the selection of feature frequency bands to improve the identification accuracy of the fault section.In the single calculation stage,the five frequency bands with the highest wavelet packet energy entropy are selected as the characteristic frequency bands,and then,the fault characteristic frequency bands with strong characterization ability are determined by intersection operation.This method can effectively suppress the noise interference and enhance the identification performance of the fault section.[Results]Experimental results show that the proposed method is highly adaptive,requires no threshold in ground fault current identification,and achieves an accuracy of 95.24%.Compared with other methods in the literature,the proposed method can maintain higher recognition performance under various working conditions.Finally,hierarchical experiment schemes are designed according to different curriculum requirements for students to gradually master the whole process from fault mechanism analysis to advanced intelligent identification methods.[Conclusions]The experimental platform and single-phase grounding fault identification method not only improve the students'hands-on and engineering application capabilities but also lay the foundation for further research and application of single-phase grounding fault detection technology in distribution networks and provide an innovative practical teaching model for the cultivation of talent in the field of power engineering.关键词
配电网/单相接地故障/故障选段/暂态零序功率特性/特征频带优选Key words
distribution networks/single-phase grounding fault/fault section location/transient zero-sequence power characteristics/optimal selection of characteristic frequency band分类
信息技术与安全科学引用本文复制引用
高伟,郑子杰,李育凤,林建新,郭谋发..基于暂态零序功率特性的配电网单相接地故障选段实验设计[J].实验技术与管理,2025,42(7):34-42,9.基金项目
福建省教育厅2022年本科高校教育教学研究项目(重大项目)(FBJG20220284) （重大项目）
福建省自然科学基金项目(2021J01633) （2021J01633）
