The Impact of Temperature on the Partial Discharge Characteristics of Moving Charged Metal Particles in Transformer Oil

The working temperature of transformer oil are different in different regions and seasons. In this paper, the partial discharge (PD) of charged metal particles in the flowing oil under different oil temperature were studied. The phi-U-N diagram of PD characteristic under different temperature were constructed, and PD amplitude and number were gotten. Metal particle trajectories were simulated using the finite element method under different temperature. Results show that when the oil temperature is below 343.15 K, PD amplitude and number reduce gradually with the temperature increasing. However, when the temperature to 343.15 K, PD amplitude begins to increase. The phase of PD is mainly concentrated in the vicinity of 90 degrees and 270 degrees. When the working temperature of transformer oil is from 333.15 K to 338.15 K under the constant velocity, the insulation performance of transformer oil is best. Trajectories of metal particles are different under different temperature, so the distortion of electric field is different, which may change the PD characteristics of metal particles in the flowing transformer oil under different temperature.