The electromagnetic parameter of power transmission include: power frequency electrical field, power frequency magnetic field, radio inference (ri) and audible noise (an).

输电线路的电磁环境参数主要包括工频电场、工频磁场、无线电干扰和可听噪声四个方面。

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There are collective parameter method which is adopted in lightning protection rules, direct measurement method, electromagnetic field method and so on.

国内外对此的研究，主要有集中参数法(我国防雷规程采用)、直接测量法及电磁场法等方法。

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