Development of the Forecast Technology of Electrical Breakdown in Gas Insulated Switchgear

本研究利用模型装置，对SF_6气体绝缘开关设备的预断技术开发进行了研究，取得了以下显著结果：(1)气体断路器触头之间的小放电产生降低了触头与容器之间的主击穿电压，因此小放电对降低主击穿电压起着重要作用。(2)主击穿电压的降低速度随小放电电流的大小和触头与容器的距离而变化。一般情况下，随着距离的减小和放电电流的增大，断路率增大。(3)在小放电产生的击穿过程中，断路器与容器之间的主要击穿的电相为：触头部分为负极，容器为正极。从以上实验结果可以清楚地看出，后面对触头部分小放电的检查使我们能够预见气体绝缘开关设备的主击穿。

This research by using the model apparatus,was carried out on technology development with foreseeing breakdoen of SF_6 gas insulated switchgear.In the following are obtained salient results.(1) The generation at the small discharge between the contact portions of the gas circuit breaker reduces the main breakdown voltage between the contact portion and the container so that the small dischage plays an important role for the reduction of the main break-down voltage.(2) The rate of reduction of the main breakdown voltage varies with the magnitude of the small dischage current and the distance between the contact portion and the container. Generally speaking,the rate increases as the distance decreases and the discharge currents increase.(3) On the breakdown generated by small discharge,the electrical phase of the main break-down between the contact portion and the container,was clarified as follows: Contact portion shows negative polarity and the container shows positive polarity.From the above experimental results.It was clarified that the latter examination of the small discharge on the contact portion enabled us to foresee the main breakdown of the Gas insulated switchgear.