Anti-interference measures and discharge location for UHVDC converter transformer partial discharge test

Partial discharge test is one of the most important tests for onsite converter transformer. However, this test is often encountered some interference, such as corona, suspended discharge, power supply-side interference and so on. The precision of transformer partial discharge test which can be affected by those interference. In this paper, the common interference factors of converter transformer test were listed. At the same time, it was introduced for high altitude converter transformer that partial discharge test interference characteristics and prevention measures. This paper focuses on introducing the discharge location for the test circuit using the methods of ultrasonic or ultraviolet imaging. There are some details given, such as ultrasonic location sensor arrangement, parameter settings and judging the fault power point. At last, combining partial discharge test of ±800kV UHVDC Yibin station converter transformer, during the test anti-interference measures and fault source location method are presented.