Experimental Study on the Interruption Characteristics Applied by Underwater Arc

Arc discharge in water can generate exceptionally high voltages, which has great potential to be used in DC fault protection applications. When the arc voltage exceeds the DC system voltage, the rising current is halted and begins to decrease until it is turned off. The increase in water pressure, arc elongation, and enhanced convective heat transfer all contribute to a rapid increase in underwater arc voltage. This paper presents a device specially designed for underwater arc discharge. Water is fully sealed in the device as arc extinguishing medium. The internal deflection contacts operated with repulsion mechanism are proposed to realize circuit open and close. An external transverse magnetic field is used to regulate the underwater arc. Furthermore, the interruption characteristics influenced by motion speed and magnetic field strength are discussed. The experimental results demonstrate that underwater arc voltage can easily exceed 5 kV, and currents of up to 17 kA can be successfully interrupted.