Performance Comparison and Modelling of Instantaneous Current Sharing Amongst GaN HEMT Switch Configurations for Current Source Inverters

Power electronics converters find their applications in future means of transportation including superconducting machines (SCM), energy storage modules and cables. Such converters operate at extreme low temperatures to ensure higher power efficiencies and power densities because of reduced semiconductor losses and filter size and weight respectively. Utilizing the advantages associated with superconducting materials, current source inverters (CSI) can outweigh their counterpart voltage source inverters and can potentially be good candidates for megawatt class motors. CSIs have been shown to offer better output power quality and reduced input side conducted electromagnetic interference (EMI), hence more suitable for SCM. Since CSI needs reverse voltage blocking switches, this paper evaluates four different GaN based configurations. The paper also models the instantaneous currents between commutating branches and models the impact of parasitic components. Tests were performed onto a three phase CSI built to verify the analysis conducted. The three-phase inverter built will be operated under extreme low temperatures.