电工技术学报2024，Vol.39Issue(z1)：106-116,11.DOI:10.19595/j.cnki.1000-6753.tces.L11013
基于经验小波变换的真空断路器关合预击穿燃弧时间分析
Analysis of Pre-Strike Arcing Time for Vacuum Circuit Breaker Closure Based on Empirical Wavelet Transform
摘要
Abstract
As an important equipment for switching capacitor banks for reactive power compensation in distribution network system,the reliability of vacuum circuit breaker directly affects the stable operation of power system.In the process of putting into the capacitor bank,when the circuit breaker is pre-strike,the closing inrush current appears synchronously until the contact is just closed,and the inrush current exists in the form of arcing,which is called pre-strike arcing.It will cause contact burning,fusion welding and material transfer,reduce the capacitive breaking capacity of the circuit breaker.Therefore,the accurate analysis of the pre-strike arcing time when the vacuum circuit breaker is closing can be used to evaluate the capacitive breaking capacity of the circuit breaker in real time. When the capacitor bank is put into the system,the inrush current between the contacts of the circuit breaker can reach up to 20 kA,and the generated electric repulsion makes the final speed of the contact change at the moment of closing.In addition,when carrying out high-voltage and high-current conditioning,hundreds of closing operations are required.The mechanical dispersion of the circuit breaker mechanism itself will also affect the accurate positioning of the instant closing point and reduce the calculation accuracy of the pre-strike arcing time.The displacement signal contains the accurate information of the instant closing point.Based on this,this paper proposes an analysis method of closing pre-strike arcing time based on empirical wavelet transform(EWT). Firstly,the least squares method is used to preprocess the collected closing displacement signal.On the premise of completely retaining the step change at the instant closing point,the environmental noise interference during signal acquisition is eliminated,which provides a guarantee for the accurate calculation of the subsequent closing pre-strike arcing time.After that,the pre-processed displacement signal is decomposed by EWT,and it is divided into six empirical wavelet function(EWF)components according to different frequency bands,and the high-frequency components of the contact closing moment are completely separated.Next,the kurtosis criterion is used to filter out the EWF component containing the effective information of the rigid point,and the effective positioning of the rigid point is realized.Finally,the starting time of the closing inrush current waveform is positioned,and the time difference between the starting time of the closing inrush current and the closing point is measured,and the pre-strike arcing time is obtained. Through carrying out simulation analysis and comparing with different methods,the error range of the pre-strike arcing time analysis method based on EWT is within 0.18 ms,which is higher than the 0.35～0.5 ms of the comparison methods,showing higher accuracy.On this basis,considering the influence of different test voltages,different inrush current amplitudes,and different mechanism speeds,field tests were carried out.The experimental results show that the mean error represented by the mean absolute error(MAE)evaluation index is always less than 0.2 ms,and the error dispersion represented by mean-square error(MSE)is always less than 0.03 ms2,which can meet the needs of accurate calculation of pre-strike arcing time without high-precision differential probes. Subsequently,on this basis,the pre-strike arcing time analysis method can be further applied to high-voltage and high-current conditioning,and the quantitative improvement of capacitive breaking capacity can be realized by precise control of pre-strike arcing energy.关键词
真空断路器/预击穿燃弧时间/位移信号/最小二乘/经验小波变换/峭度Key words
Vacuum circuit breaker/pre-strike arcing time/displacement signal/least squares/empirical wavelet transform/kurtosis分类
信息技术与安全科学引用本文复制引用
张登奎,张立岩,李志兵,张然,董恩源..基于经验小波变换的真空断路器关合预击穿燃弧时间分析[J].电工技术学报,2024,39(z1):106-116,11.基金项目
国家电网公司总部科技项目资助(5500-202255129A-1-1-ZN). （5500-202255129A-1-1-ZN）
