Study on partial discharge characteristics of corona discharge in transformer oil under oscillating switching impulse voltage

Partial discharge characteristics of corona discharge in transformer oil under the oscillating switching impulse voltage is investigated in this paper. A oscillating switching impulse voltage generator has been set up to produce the oscillating switching impulse voltages which satisfy the requirements of IEC60060-3 standard, furthermore the generator can produce positive or negative oscillating switching impulse voltage. A low inductance 50Ω resistor and 3.5MHz highpass filter is used to measure the partial discharge. Partial discharge of corona discharge in transformer oil under the positive and negative oscillating switching impulse voltage is carried out in this paper. Experiment results show that the amplitude of PD and the number of PD is increased by the amplitude of the oscillating switching impulse voltage, Moreover, corona discharge in transformer oil under oscillating switching impulse voltage exhibits the polar effect.