多回超高压交流输电线路平行架设时的无线电干扰特性研究

为分析多回超高压交流输电线路平行架设区域的无线电干扰分布特征,建立500kV单回与同塔双回超高压交流线路平行架设时的有限元模型,利用激发函数法分析不同线路间距、对地高度以及相序排列下平行架设区域无线电干扰分布特征,并通过实例验证了模型的有效性。结果表明,线路间距减小会使无线电干扰高场强区域减小,但幅值会有一定提高;增大对地高度会使无线电干扰场强幅值减小,但衰减速度会变慢,边相外20m处的场强值也有所增加;改变导线相序排列对输电走廊中部区域场强分布有一定影响;模型可较准确反映实际无线电干扰分布特征。

Study on Radio Interference Characteristic of Multi-turn EHV AC Transmission Lines in Parallel Erection

In order to get the radio interference characteristics of multi-turn EHV AC transmission lines in parallel erection, the finite element model of 500 kV single-circuit and double-circuit high-voltage AC lines was established, and the radio interference (RI) characteristics of the parallel erection area were analyzed and studied by using the RI excitation function method. The characteristics of RI distribution in the parallel erection area with different line spacing, ground height and phase sequences are discussed. The case study validated the accuracy of the proposed model. The results show that the decrease of the line spacing can reduce the area of the RI high field strength, but the maximum amplitude will increase. The increase of the ground height will slow down the attenuation of RI field intensity with the distance, but will increase the RI field strength at 20 m. The RI filed strength between two power lines can be influenced by changing the phase sequence. The calculation model can accurately reflect the RI distribution.