聚合物电介质的击穿与空间电荷的关系

Relationship between Breakdown in Polymer Dielectrics and Space Charge

空间电荷是聚合物在交流或直流高压作用下发生老化和击穿的主要原因之一,以往的研究基本认为由于空间电荷的注入并集聚使介质内部电场严重畸变,从而使介质老化最终引起击穿,相应的解释模型都是在有外加电场作为前提建立的。但是,根据最新的实验研究发现,外加电场并不是介质击穿的必要条件,介质的击穿可以发生在空间电荷的脱阱过程中而与外加电场无关。本文阐述了空间电荷与绝缘高聚物的老化和击穿的关系,并且结合最新的研究成果,揭示了介质内部空间电荷的存在是击穿的重要条件,而且击穿是发生在空间电荷的脱阱过程中。

Under AC or DC stress, space charge is one of main causes of aging and breakdown in polymers. Previous research work considered that space charge injection and accumulation in dielectrics could seriously deform dielectric internal electric field, and ultimately led to aging or breakdown. Corresponding interpretive models for these phenomena took applied field as precondition. But, according to latest research achievement, it finds that applied fieM is not a necessary condition. Dielectrics breakdown can also occur during the detrapping process of space charge without applied field. This investigation summarizes the relationship between space charge and aging or breakdown in polymers. It clarifies that space charge is a vital condition for dielectrics breakdown and detrapping process of space charge can lead to dielectrics breakdown.