Simulation Study on Transient Process of Liquid Metal Current Limiter

High voltage direct current (HVDC) transmission lines produce large currents when short-circuiting endanger the safety of the power system, causing huge economic losses, etc. In this work, a simulation model of current limiting test circuit based on PSCAD is proposed by taking advantage of the high conductivity and self-recovery properties of liquid metal. The transient process of the liquid metal current limiter(LMCL) is analyzed by setting the equivalent time-varying nonlinear conductance. Comparing the voltage and current waveforms of the short circuit test without the LMCL and the short circuit test circuit with the LMCL, it is found that the short-circuit test with the LMCL has a significant current limiting effect, which can reduce the short-circuit current to 1.997kA when the fault occurs in a power system with a level of 400V. And explored the current limiting effect of LMCL at different voltage levels, compared with no LMCL, the current limiting rate of the short circuit test with LMCL is about 76%, which provides the possibility for the promotion of LMCL in different occasions.