Partial discharge is mainly used to check whether there are local defects of discharge sources in large electrical equipment. With the increasing voltage level and capacity of the power system, the measurement of partial discharge of transformers has been paid more and more attention by the operation and management units of large power transformers. , it is one of the important indicators to determine the reliability of the insulation system. In addition, the partial discharge tester can also analyze and analyze whether there is an area with excessive dielectric strength inside the transformer, which can effectively reduce the harm caused by the long-term safe operation of the transformer. Transformer partial discharge can be used in power transformers, transformers, arresters, etc. ,
Transformer partial discharge test
First of all, the partial discharge test should be performed in a dedicated shielding room. The external interference signal can be effectively shielded by the dedicated shielding device. If you use it on site, we need to pay attention to many details. Conditions, noise, etc., may affect the results of partial discharge tests.
Before the measurement, we still need to power off some electrical equipment. Then, measure the grounding resistance with a large grounding grid grounding resistance tester to ensure that the grounding resistance is very good. If the conditions are not suitable, it is recommended to measure the partial discharge in the middle of the night, so that the voltage is relatively stable. , the electromagnetic interference is relatively small. Of course, this is only a common way to deal with interference. If the on-site interference is not enough, it is recommended to add a shielding room.
Several factors for the occurrence of partial discharge
The electric field is too concentrated at a certain point; b. The solid medium has bubbles, and the harmful impurities are not removed; c. The oil contains water, gas, and suspended particles; d. In different medium combinations, there is serious electric field distortion at the interface.