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Due to its significant attributes, the liquid metal current limiter (LMCL) is considered as 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.

Arc explosion accidents in live working seriously threaten the safety of power workers. At present, the mainstream arc protective clothing material is aramid and blends of aramid. However, aramid will produce toxic gas under high temperature combustion, which is harmful to the health of operators. Therefore, it is a special challenge to study fabrics that are friendly to the human body and have a highly protective performance to protect electrical workers. Polyimide is nontoxic and has excellent high temperature resistance, flame retardation, and mechanical properties. In this paper, polyimide was proposed to be used as an arc protective clothing material. In order to explore the feasibility of polyimide in the field of arc protection, molecular dynamics simulation was used to compare the heat resistance of polyimide and aramid in terms of bond order and glass transition temperature. Referring to ASTM F1959 and IEC 61482-1-1, an arc test apparatus was built to test the protective properties of materials. The protection failure mechanism was analyzed by comparing the safety protective performance of polyimide and aramid fabric under the arc. It was found that polyimide has better arc thermal protective performance and break open threshold. The simulation and test results show that polyimide can be used as a material for arc protective clothing to improve protective performance.

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