Research on application of adjustable reactor technology in UHVDC converter transformer partial discharge test

As the most severe assessment method in transformer field handover tests, partial discharge test can effectively detect insulation faults inside transformer. In this article, the adjustable reactor has been firstly proposed and used in the partial discharge field handover test of the converter transformers in Jinping-Sunan 800kV DC Transmission Project. The capacitive reactive power of the converter transformer under test has been analyzed and inductive compensation has been calculated. The reluctance of adjustable reactor can be adjusted smoothly, therefore the inductive compensation can be changed continuously in real time and under-compensation or over-compensation problems of fixed reactor can be avoided. The test method has been validated in field handover test in Jin-su UHVDC project and the filed partial discharge test has been completed successfully.