Investigation of liquid metal current limiter based on a novel topology

摘要

In this paper, a novel liquid metal current limiter (LMCL) is proposed allowing for the large rated current and considerable fault current energy dissipation in DC power system. According to this topology, the LMCL consists of a fast switch and several liquid metal current limiting units in parallel. Firstly, a simulation model of this LMCL is built to calculate the fault current commutation process and it is then experimentally verified. Based on this model the duration of current commutation is analyzed allowing for different factors including rising rate of current, contact types of main switch and the inductance of branch circuit, which directly affects the design of parallel current limiting unit to avoid its early arc ignition before the completion of current commutation. Finally, Its current limiting performance is discussed with different number of channels in LMCL unit, it indicates that arc voltage increases with the channels quantity of LMCL unit.