Experimental study on the ion migration of rod samples for high voltage DC porcelain support insulators

The ion migration testing used for DC porcelain support insulators was carried out in this paper. Ten rod samples for DC porcelain support insulators were subjected to a long-term ion migration testing in our laboratory in accordance with the reported procedure of IEC. The changes of Na⁺ distribution along with the samples under the long-term testing were analyzed, compared to that of the untested samples. The mechanical performance of the tested samples was verified by using bending breakdown testing. The research findings indicate that the ion migration testing designed for support insulators does not cause Na⁺ ion apparent migration in the samples and does not influence the mechanical performance of the tested samples