多柱并联电阻片柱冲击电流分布不均匀系数测量方法的研究

Study on Measuring Methods of Non-uniform Coefficient of Impulse Current Distribution of Multi-column Varistors in Parallel

以非线性金属氧化物电阻片为核心元件组成的过电压保护装置动作时,要吸收大量能量,需采用多柱电阻片柱并联结构。有关标准中明确规定,多柱电阻片各柱之间电流分布不均匀系数β应不大于1.1。在测量检测时,受电流冲击测试设备能力的限制,不能同时进行几十柱甚至上百柱电阻片柱的电流分布不均匀系数的测量。根据金属氧化物电阻片伏安特性的特点,提出了一种测量多柱并联电阻片柱电流分布不均匀系数的方法,简单可靠,可以在实际工程中使用。

Multi-column varistors in parallel structure are necessary to be used for overvohage protection devices which are composed of some nonlinearity metal oxide varistors as core components, to absorb a lot of energy when they operate. A non-uniform coefficient β of current distribution between multi- column varistors should not be more than 1.1 which is clearly defined in related standards, It is impossible to test tens of columnsor even several hundred columns in parallel and measure the current through each one at the same time as the result of being limited by the capacity of current impulse test equipment. A method to test the non-uniform coefficient of current distribution between muhi-column varistors is proposed according to the voltage/current （V1） characteristics of metal oxide varistors. The method is simple and reliable, and can be applied in practical engineering.