Analysis of Partial Discharge Test of Transformer Caused by Excitation Transformer Fault

Abstract

Partial discharge refers to a discharge phenomenon in which a portion of a region is discharged due to an electric field and there is no breakdown between the applied voltage conductors in an operating state. For transformers above 110kV, the partial discharge test is an effective means and method for verifying the insulation level of the transformer. Due to the limitations of the field test conditions, the partial discharge test of the transformer generally adopts a low-voltage side compensation press and a method of inducing a test voltage level on the high-voltage side. The state of the test equipment directly determines whether the experimental results meet the standard requirements. In this paper, we analyze the situation that the excitation is self-discharged and then transmitted to the transformer of the test, which results in the test result not meeting the standard requirements. At the same time, the excitation is returned to the factory for disintegration, and the cause of the accident is analyzed to provide experience and support for future field tests. During partial discharge test of transformer, the amount of partial discharge caused by the failure of the test equipment is difficult to distinguish. This type of problem can only be avoided by regular maintenance of the test equipment or by applying a voltage rise to the equipment.