Study of the Arc Ignition Characteristics of Liquid Metal Current Limiter Based on Magnetic Pinch Effect

The liquid metal current limiter (LMCL) based on magnetic pinch effect has a good application prospect in the future LV and MV power system with its merits of small volume, simple structure, self-activation and self-healing in case of a fault. The high-speed camera was adopted to observe the dynamic pinch process of liquid metal. Then its pre-arcing time was measured. In addition, this physical process was also studied and analyzed by simulation. The arc ignition characteristics of liquid metal were fully investigated with the three aforementioned methods on account of different factors. They are the initial height of the liquid's free surface, roughness of the spacer's channel and the increasing rate of prospective current. The results demonstrate that the pinch process of liquid metal always includes two processes, i.e. the pinch process from its free surface and the direct pinch process of the liquid column in the channel. Their effects and influences for each was obtained, which can act as the basis for structural design and performance optimization for future LMCLs.