Optimised design consideration of suspension choppers in Maglev train using SiC MOSFET modules

Abstract

Electromagnetic suspension (EMS) Maglev trains attracted to suspend above a track is a green type of track transportation. The suspension control box adopting a closed-loop feedback controller outputs a levitation current that flows into the electromagnets producing a desired magnetic force to levitate the train. Without contact frictions, such a promising type of transportation saves considerable electricity for propulsion. Minimising the volume and weight of Maglev trains attracts great research interests and continuous engineering effort as that is closely correlated with levitation power consumption and, more importantly, the construction cost. This paper mainly discusses volume and weight optimisation of suspension control box that contains a suspension chopper in EMS Maglev trains using the state-of-the-art SiC MOSFET modules. By analysing the mission profile of a typical suspension chopper, SiC MOSFET is found to be perfectly suitable for suspension chopper optimisation because of its low power losses. An optimised heatsink design of suspension chopper is given, whose volume is only 21% of the previous design. By utilising a RC snubber, the new SiC MOSFET suspension chopper prototype is built without showing serious voltage ringing. This provides a promising prospect for further optimisation of suspension control systems.