500kV线路长串绝缘子的冰闪泄漏电流

Icing Flashover Leakage Current of Long Insulator Strings in 500 kV Transmission Line

为给我国污秽、覆冰地区架空输电线路外绝缘设计提供参考,在国网电力科学研究院环境气候试验室进行了污秽、覆冰条件下500kV典型线路绝缘子串冰闪试验。同时研制出一套泄漏电流测量系统,并对冰闪过程中泄漏电流谐波含量、幅值包络线的变化进行了研究。研究表明:冰闪过程中泄漏电流的变化发展与放电过程以及冰的融化状态紧密相关,泄漏电流的特征量能够明显体现出冰层的状态变化以及放电的发展,因此泄漏电流可以作为判断绝缘子覆冰、融冰期间闪络的一个监控条件。

In order to provide a reference to the overhead transmission line external insulation coordination for the heavy icing and pollution regions of China, 500 kV long insulator string pre-contaminated icing flashover was tested in the artificial climate laboratory at State Grid Electric Power Research Institute { SGEPRI} of SGCC. Based on the virtual instrument, a leakage current measurement system used to test the icing flashover leakage current was developed with current transformer , and the precision of this system was also tested. The research results indicate that, the leakage current can reflect the process of icing flashover, and the leakage current＇s change and development are closely related to the discharge process and the ice melting state of insulator strings. In the voltage withstand test, whether the partial arc can finally develop to be flashover or not is obviously represented by the waveform of leakage current and the change trend of leakage current. Hence, the leakage current ean be used as an online monitoring parameter for forecasting the insulator string flashover of icing regime or melting regime.