Study on the formation of arc plasma on the resistive wall liquid metal current limiter

Abstract

Abstract Due to its significant attributes, the liquid metal current limiter (LMCL) is considered a new strategy for limiting short-circuit current in the power grid. A resistive wall liquid metal current limiter (RWLMCL) is designed to advance the starting current-limiting time. Experiments are performed to investigate the dynamic behaviors of liquid metal, and the influence of different currents on the liquid metal self-shrinkage effect is compared and analyzed. Furthermore, the liquid metal self-shrinkage effect is mathematically modeled, and the reason for the formation of arc plasma is obtained by simulation. The laws of arc plasma formation and the current transfer in the cavity are revealed, and the motion mechanisms are explained by physical principles. The simulations are in accordance with the test data. It is demonstrated that the sudden change of the current density at both ends of the wall causes the liquid metal to shrink and depress under the electromagnetic force, and the current starts to transfer from the liquid metal path to the wall resistance path. The RWLMCL can effectively advance the starting current-limiting time.