稍不均匀电场空气间隙击穿电压计算的新方法  

A New Calculation Method for the Breakdown Voltage of Air Gap in Slightly Uneven Electric Field

作　　者：舒胜文[1] 阮江军[1] 黄道春[1] 普子恒[1] 邱志斌[1] 

机构地区：[1]武汉大学电气工程学院,武汉430072

出　　处：《高电压技术》2015年第2期662-668,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2011CB209404)~~

摘　　要：空气间隙的击穿电压是高压输变电工程外绝缘设计的重要依据,而电场分布均匀性是间隙击穿电压的主要影响因素之一。为此,提出了一种基于电场分布特征参数和支持向量机的空气间隙击穿电压计算新方法。采用该方法对球隙和球–板间隙2种稍不均匀电场空气间隙的击穿电压进行了计算,并与基于流注起始判据的计算结果和试验结果进行了对比。以试验结果为基准值,提出的方法对球隙和球-板间隙击穿电压计算结果的平均绝对百分比误差分别为1.64%和1.62%;而流注起始判据计算结果的平均绝对百分比误差分别为1.03%和5.26%。为获得精确的计算结果,随着电场分布不均匀性的增大,流注起始判据中的临界电荷数需进行修正,而这缺乏具有普适性的修正方法。提出的方法为输变电工程间隙击穿电压的获取提供了一条可能的新途径。Breakdown voltage of air gap is important for the design of external insulation in high-voltage transmission and distribution projects, and one of its main influencing factors is the uniformity of electric field distribution. We proposed a new calculation method for breakdown voltage of air gap based on electric field distribution feature parameters and support vector machine. The method is applied to calculate the breakdown voltages of air gap in slightly uneven electric fields in sphere gaps and sphere-plane gaps, and the results are compared with the calculation results based on the streamer inception criterion and with test results. Taking the test results as the reference, the mean absolute percentage errors are 1.64% and 1.62% respectively for the breakdown voltages of sphere gaps and sphere-plane gaps calculated by using the proposed method; the errors are 1.03% and 5.26% for the calculated results using the streamer inception criterion accordingly. In order to get accurate calculation results, the critical charge in the streamer inception criterion has to be modified as the non-uniformity of electric field distribution increases, but there is no universal revised method for this modification. The proposed method is a possible way for acquiring the breakdown voltage of air gaps in power transmission and distribution projects.

关 键 词：空气间隙 稍不均匀电场 击穿电压 支持向量机 流注起始 临界电荷数 

分 类 号：TM85[电气工程—高电压与绝缘技术]