Gas Production Characteristics of Partial Discharge in Needle-plate Electrodes under Typical Vibration Conditions in a UHV Shunt Reactor

A ultra-high voltage (UHV) shunt reactor is accompanied by continuous strong vibration during operation, and its internal partial discharge is often associated with mechanical vibration of its electrodes. To explore the mechanism of the effect of electrode vibration on the partial discharge inside the reactor, a joint vibration-partial discharge test platform was established based on a partial discharge model of the oil-paper insulated needle board electrode. The influences of the amplitude and frequency of vibration on the partial discharge characteristics of the needle board in oil under power frequency voltage were studied. The results show that with the increases in the amplitude and frequency of vibration, the discharge process is intensified, the discharge repetition rate and the maximum discharge quantity increase, and the negative half-cycle discharge pattern exhibits “zero crossing”. The discharge intensity of the needle-plate electrodes is affected by velocity of the oil flow velocity and field intensity; the field intensity has a more significant effect on the partial discharge. When partial discharge occurs without vibration, the characteristic gases produced by the needle-plate discharge are mainly H
₂
and C
₂
H
₂
, and contain a small amount of CH
₄
and C
₂
H
₄
. With the increases in the amplitude and frequency of vibration, the content of each characteristic gas increases, and vibration changes the spatial distribution of dissolved gas in the oil by driving the motion of the insulating oil around the electrode.