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

作　　者：张登奎 张立岩 李志兵 张然 董恩源[1] Zhang Dengkui;Zhang Liyan;Li Zhibing;ZhangRan;Dong Enyuan(School of Electrical Engineering Dalian University of Technology, Dalian 116024 China;China Electric Power Research Institute ,Beijing 100192 China)

机构地区：[1]大连理工大学电气工程学院,大连116024 [2]中国电力科学研究院有限公司,北京100192

出　　处：《电工技术学报》2024年第S1期106-116,共11页Transactions of China Electrotechnical Society

基　　金：国家电网公司总部科技项目资助(5500-202255129A-1-1-ZN)。

摘　　要：作为容性投切的重要设备,真空断路器的可靠运行对于维持电网的稳定至关重要。在并联电容器组投入时,真空断路器会出现合闸预击穿燃弧,导致触头的烧损、熔焊和材料转移等问题,严重影响其开断性能。因此,对断路器关合时的预击穿燃弧时间进行准确分析,不仅可以对容性开断水平进行实时评估,还可以应用于高压大电流老炼中,实现容性投切能力的定量提升。基于此,该文提出一种基于经验小波变换(EWT)的真空断路器关合预击穿燃弧时间分析方法。首先,对断路器的合闸位移信号进行最小二乘预处理,降低信号采集时的干扰;其次,对处理后的位移特征曲线进行EWT分解,利用峭度准则选取能准确反映刚合点的特征量,结合预击穿涌流波形,得到关合预击穿燃弧时间;最后,通过模拟分析和现场试验,对不同影响因素下的关合预击穿燃弧时间开展分析。相较于传统方式,该分析方法可在现有传感器的测量基础上,大幅提高预击穿燃弧时间的检测准确度,为断路器容性开断能力的准确评估和定量提升提供可靠支撑。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 wave

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 

分 类 号：TM561.2[电气工程—电器]