750kV同塔双回交流输电线路电磁环境研究

Study on electromagnetic environment of 750 kV double-circuit AC transmission lines on the same tower

我国西北电网规划的多条750kV交流输电线路位于高海拔地区,无线电干扰和可听噪声等电磁环境问题更加严重。因此,研究750kV交流输电线路电磁环境问题对我国750kV输电工程建设具有重要意义。计算一条典型750kV同塔双回交流输电线路,最大运行电压分别为775.0kV、787.5kV、800.0kV下无线电干扰、可听噪声、线路下方距地面1m水平线上工频电场强度、导线最低对地距离和走廊宽度。按文献给出的电磁环境标准进行讨论,结果表明:通过选择合适的线路参数(导线最低对地距离、海拔高度等),可满足3种最大运行电压下电磁环境指标要求。

Since several planning 750 kV AC transmission lines of China northwest grid locate at high altitude above sea level area, corona loss is rigorous, and the RI level and AN will become even worse. Hence, the study on electromagnetic environment of 750 kV AC power transmission lines is of significance for the construction of 750 kV AC transmission hnes in China. The electromagnetic environment problems of a typical 750 kV double-circuit AC transmission line on the same tower, with maximum operating voltage 775.0 kV, 787.5 kV and 800.0 kV were analyzed. RI level, AN, the maximum power frequency electric field intensity （EFI）, the minimum distance to ground and corridor width were calculated and discussed according to the electromagnetic environment control criteria given in some references. Discussion results show that the electromagnetic environment of three maximum operating voltage classes can satisfy control criteria by selecting suitable line parameters, such as the minimum distance between lowest phase conductor and ground surface, altitude above sea level, et al.