高压交流输电线路电晕可听噪声机理及理论模型

摘要

为预估高压交流输电导线产生的电晕可听噪声,研究了电晕可听噪声的产生机理及其理论预估模型.高压交流输电线电晕产生正负离子,基于Drude模型研究了正负离子的运动规律,进而阐明了电晕可听噪声的产生机理.在此基础上,进一步运用Kirchhoff公式得出电晕可听噪声的理论预估模型,并针对特定导线布置形式计算了典型的二倍工频分量的声压及声场分布.数值计算结果表明,可听噪声中的二倍工频分量衰减缓慢,且在导线附近区域存在显著的干涉现象,计算的结果会随着离子浓度的变化而变化,但声压级分布曲线的形状不会变化.该模型适合于电晕可听噪声的计算,有助于指导输电线设计.%To predict the levels of corona audible noise resulting from high voltage AC power transmission lines, the mechanism of corona audible noise and its theoretical prediction model are investigated. On the basis of the Drude model, the motion of positive and negative ions produced by corona of high voltage AC power transmission lines is analyzed and the mechanism of corona audible noise is explained. In terms of Kirchhoff formula, the theoretical prediction model is established, and for a certain line configuration, the acoustic field distribution of the typical component with twice power frequency is computed. The numerical result shows that the audible noise component with twice power frequency attenuates slowly and leads to an obvious interference near the transmission lines. The magnitude of sound pressure level distribution curve undulates with the ion concentration, but the shape gets unchanged. The model is suitable for evaluating levels of corona audible noise to guide transmission line designs.