A novel solid state fault current limiter for DC power distribution network

DC power distribution network is specifically used in industrial manufactures and aircraft/ship power distribution since it can provide flexible interface to various power converters with high efficiency and less conversion stage. The protection for DC power distribution system is more difficult compared with those AC systems since there´s no natural zero crossing point for the current. Low shortcut impedance will cause high current rising rate, which can bring heat, arc and electrical force damage to the DC power distribution grid in a quite short time that the DC breakers hardly act. This paper proposed a solid state fault current limiter (FCL) using a combined power switch. Solid state FCL can achieve fast response to the fault current in the DC power grid, without special requirement of the cooling system. Using a combined power switch instead of single fully controlled power electronics component can reduce the steady power loss while normal working states. When fault states occurs, the power electronics control technique can strictly limits the fault current beneath a certain desired range. In that way, the fault damage can be limited. Experiment results are taken to prove this design.