覆冰情况下10kV带间隙氧化锌避雷器工频续流特性研究

Power Frequency Continuous Current Study of 10kV Air Gapped Arrester under Icing Conditions

搭建了"工频—冲击"联合加压试验平台,模拟外间隙避雷器在交流运行条件下遭受雷击的工况,对盘型和针型两种结构的10kV带间隙避雷器进行了试验研究,获得了不同覆冰程度下的避雷器工频续流闪络特性。试验结果表明在"工频—冲击"联合加压作用下,冲击电弧沿避雷器间隙击穿;在清洁条件下,工频续流电流可以忽略不计,随着覆冰厚度的不断上升,工频续流幅值与持续时间不断增加,且续流电流主要沿续流电弧与避雷器表面流过试品;在30 mm厚度的重度覆冰条件下,两种试品均可以在工频电流过零时有效熄灭续流电弧。

In the paper, ＂power frequency - pulse＂ combined voltage test platform is built to sinmlate the lightning strike condition of arresters with gaps under AC working condition. Experimental studies of disk-type and needle-type arresters have been done, and the flash-over characteristics of power-frequency continuous current under different icing degrees are obtained. The results shows that, under the condition of ＂power frequency-impulse＂ combined voltage, impulse arcs develops along the air gaps of arresters. Under clean condition, the power-frequency continuous current can be neglected. With the increasing of icing degree, the amplitude and duration of power-frequency continuous current is increased, which passes the arresters through the continuous arc and arrester surface. Based on the test results, it can be known that, when the icing thickness is 30mm, the two kinds of test species can effectively extinguish the power-frequency continuous arcs when the power-frequency current passes zero.