超高压三相交流线路电晕电流的数值计算

Numerical Calculation for Corona Current of Ultra-high Voltage Three-phase AC Lines

电晕损耗计算是超高压线路选型与设计的重要内容之一,而电晕电流与电晕损耗的计算直接相关。基于此,给出一种简单可行的超高压交流线路电晕损耗数值计算方法。该方法在分裂导线的每根子导线中设置3个模拟电荷,通过自调整变化步长,寻得使每根子导线电压不均匀性误差至最小的模拟电荷位置。确定模拟电荷的数目及其在分裂导线子导线中比较合理的放置位置后,通过对分裂导线离子流场的计算得到线路的电晕损耗及电晕电流。通过实际算例分析,计算了三相四分裂输电线路各相电晕电流以及相应的电晕损耗,同时给出了各相导线周围的空间电荷分布情况。对比验证结果表明,采用该方法计算线路总电晕损耗的结果较为准确。

Corona loss calculation is one of important contents for selection and design of ultra-high voltage lines, and corona current is directly related to the calculation. Therefore, this paper presents a kind of simple and feasible numerical calculation method for corona loss of ultra-high voltage AC lines which is to set three analog charges in each sub-conductor of bundled conductors and find out the location of the analog charge that makes nonuniformity error of each sub-conductor minimum by self-adjusting step length. After determining numbers of analog charges and reasonable locations in sub-conductors of bundled conductors, it then obtains corona losses and corona currents of lines by calculating ion-flow field of bundled conductors. By means of actual example analysis, it works out corona current of each phase of three-phase four bundled conductors and relevant corona losses, and provides distribution of space charges around the conductor of each phase. Comparison and verification indicates the calculated result of total corona loss of the line by using this method is more accurate.