598 / 2017-05-15 18:05:46

Investigation of Liquid Metal Current Limiter Based on a Novel Topology

DC Power systems,fault current limiter,fast switch,liquid metal

In this paper, a novel liquid metal current limiter is proposed allowing for the large rated current and considerable fault current energy instored in DC power system. According to this topology, the LMCL consists of a fast switch, several liquid metal current limiting units and an energy dissipation resistor 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 several 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 curent limiting unit to avoid its early arc ignition before the completion of current commutation. Finally, Its current limiting performance is discussed with and without energy dissipation resistor, it indicates that the parallel resistor has a positive effect on fault energy dissipation to reduce the arc erosion of spacer channel for a longer service life.