Technology Literature

The harm of partial discharge test of transformer and the importance of test

When the transformer generates partial discharge under the working voltage, even a very weak discharge will cause corrosion to the insulating material. In the long run, the accumulation effect will affect the dielectric property of the insulation, causing the insulation to deteriorate until the insulating layer is finally broken. The chemical elements generated during the discharge process will accumulate on the solid insulation, which further excites the discharge of electrical equipment, and it is easier to break through the insulation in areas with high field strength and insulation damage. And eventually form a carbonized layer through the insulation

One of the causes of transformer failure is dielectric breakdown, which is mainly caused by partial discharge, which causes insulation deterioration and even breakdown. With the development of transformer fault diagnosis technology, people gradually realize that partial discharge is the root cause of many faults and accidents of transformers, so the test of partial discharge is getting more and more attention. In recent years, 50% of power transformer accidents above 110kV are caused by inter-turn short circuit under normal operating voltage, and also caused by partial discharge. Therefore, partial discharge measurement has been taken as one of the important projects for 220kV transformer handover and overhaul. Condition monitoring and troubleshooting will be very effective.

Through the discussion of transformer-related tests, we can see that in the handover test, the relevant test of the transformer is the inspection of the overall insulation of our transformer.

Only by conducting an effective insulation test on the transformer can we judge whether the insulation of the transformer meets our operational requirements. This is the main means by which we can judge whether the transformer can be put into operation.

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