陡波试验寻找合成绝缘子内部缺陷

为了检验陡波试验对于发现合成绝缘子内部故障的有效性,分别模拟绝缘子内部不同部位有导电性、半导电性通道,小气泡长气泡和芯棒与护套间不粘连故障的绝缘子,并分别在故障绝缘子和正常绝缘子上施加不同陡度的陡电压波,同时用有限元分析软件计算绝缘子的电场分布,以确定绝缘子在陡坡试验中是否会击穿,计算结果与实验结果相一致,研究结果表明陡坡试验在检验合成绝缘子内绝缘严重故障方面很有效,但对一些小的故障不易检出。

VERIFICATION ON EFFECTIVENESS OF STEEP-FRONT WAVE IMPULSE VOLTAGE TEST TO FIND INTERNAL DEFECTS INSIDE COMPOSITE INSULATORS

In order to verify the effectiveness of steep-front impulse voltage test in finding the internal defects in composite insulators, some defects at different places inside the composite insulators are simulated. They are conductive channel, semi-conductive channel, airy channel, little air bubble, long air bubble and non-adhesion between the core and the hosing. The steep-front wave impulse voltages with different steepness are applied to defective and normal composite insulators respectively. The electric field distribution in the insulators are calculated with finite element analysis software to define whether the insulators will be broken down during the test and the calculation results are coincident with testing results. The research results show that the steep-front wave impulse test is effective for verifying the serious faults existing in the internal insulation of composite insulators. However, it is not easy to find the tiny defects by this method.