110kV复合型放电间隙避雷器的电气性能

Electrical Performance of 110kV Compound Discharge Gap Lightning Arrester

为降低110kV架空输电线路雷击跳闸率,基于多短间隙过零熄弧后不重燃的机理,提出一种由多短间隙结构和单个大间隙相串联而成的复合型放电间隙避雷器。该避雷器允许多短间隙被击穿建立电弧通道,在间隙中产生的高气压作用下,电弧被推出短间隙。在工频续流自然过零熄弧后,由于分布到单个短间隙上的最大电压不足以重新燃弧,以确保电弧不发生重燃。该文首先通过工频续流试验考核多短间隙过零熄弧后不重燃的可靠性;进而通过雷电冲击试验、淋雨试验和污秽试验,检验该避雷器的电气性能。试验结果表明复合型放电间隙避雷器具有良好的工频续流遮断能力,且电弧不会发生重燃;具有良好的雷电冲击特性和淋雨特性,适用于重污秽地区。复合型放电间隙避雷器满足110kV输电线路安全运行的要求,并能够在继电保护动作前可靠熄灭电弧使其不发生重燃,可用于110kV输电线路防雷。

In order to reduce the lightning trip-out rate of 110kV transmission line, a kind of 110kV lightning arrester with compound discharge gap is proposed based on the principle of free-of-reignition of multi-short-gaps after extinguishing at current zero. The arrester is connected in series by multi-short-gaps structure and one large discharge gap. It allows multi-short-gaps to be broken down and establish arc channels. Under the action of high pressure generated in the short gap, the arc is removed outside. The arc extinguishes after power frequency follow current zero and the maximum voltage distributed on a single short gap is not enough to reignite, which ensures that the arc will not reignite again. In this paper, the reliability of free-of-reignition of multi-short-gaps after extinguishing at current zero was evaluated by power frequency follow current test. And then lightning impulse test, raining test and pollution test were performed to evaluate the electrical performance of the lightning arrester. The test results show that the arrester has good ability to interrupt power frequency follow current and the arc will not reignite. The excellent characteristics of the device under lightning impulse and raining are proved, and it can be applied to the heavily polluted areas. In conclusion, the compound discharge gap lightning arrester satisfies the requirements of reliable operation of 110 kV transmission line and enables reliable arc extinction before relay protection action. It means that the arrester can be used for lightning protection of 110 kV overhead transmission line.