特高压直流线路可听噪声的边界元方法

Boundary element method of audible noise for UHV DC transmission lines

基于边界元原理建立了特高压直流输电线路导线表面最大电场计算方法,利用广义极小残值法求解边界元形成的稠密非对称方程组直接获得导线表面最大电场,结合美国邦纳维尔电力局经验公式进行特高压直流线路可听噪声的精度验证和影响因素特性分析。计算结果表明,基于边界元法的可听噪声计算与现场测量值的最大相对误差5.0%,其计算精度明显大于基于有限元法和马克特一门格尔法的可听噪声计算结果;避雷线参数变化对可听噪声的影响极小;导线半径,导线分裂数或双极导线间距的增加,可听噪声分布都呈逐渐变小的趋势;然而导线对地距离或导线分裂间距增大,可听噪声呈先衰减后增大的趋势。

Combined the Bonneville Power Administration（BPA） experience formula and the maximum conductor surface gradient, whose calculation method was presented by boundary element method and solved by the generalized minimal residual algorithm, the accuracy verification and influence character- istic for the audible noise（AN） of ultra high voltage（UHV） DC transmission lines were analyzed. The numeric results demonstrated that the maximum relative error between theoretical calculation and mea- surement value for the presented method is 5%, where the presented method achieves higher accuracy in comparison of Markt-Mendele method and finite element method. Meanwhile, the effect of overhead ground wire causes no influence on the variation of AN. Furthermore, the AN trend appears to be the gradual attenuation with the increase of the conductor radius, the bundles or the bipolar distance. How- ever, the AN trend is decreased first and then increased with the increase of conductor height or bundle radius.