An experimental system of AC arc discharge in water was designed with pole-poleelectrodes and a peak voltage of 1500 V and a test circuit was set up using virtual instrumenttechnology.The mechanism of an AC plasma arc generated in water was analyzed.The voltagecurrentcharacteristic of the AC plasma arc was obtained from the waveform.The temperaturecharacteristic was tested with a spectrum diagnosis system,and the effect of different electrodematerials on the striking voltage and peak current was analyzed.The results show that when apower supply of 6 kW is applied on electrodes with a gap of 2 mm in water,the striking voltageis from 900 V to 1300 V,the arc voltage is from 40 V to 100 V,the arc current is from 2 A to7 A,and the zero rest period is from 1 ms to 2 ms.In addition,the arc voltage and current aredifferent for electrodes in aluminum,copper and stainless steel.The arc voltage is lower and thecurrent is higher for an aluminum electrode than those for copper and stainless steel ones.Thehighest temperature of the arc is 7643 K.
