A gallium nitride device based switched capacitor multilevel converter for UPS applications

A single phase gallium nitride devices based switched capacitor multilevel, multiport inverter for UPS applications is proposed in this paper. This UPS system enables the seamless transfer between the grid-connected and backup modes of operations, which ensures the continuity of the power to the critical load. The proposed UPS system also harnesses the superior characteristic of the switched capacitor circuit and the GaN devices. Therefore, it has fewer semiconductor devices, faster switching speed and boost functionality. The system can achieve multi-port multi-level operation. Hence, the harmonics of the output voltage can be reduced and the voltage stress of the switching devices can be lower. The absence of the passive components help to reduce the overall size and increase the overall power density. The operation of the proposed UPS system is explained and confirmed by the simulation with Matlab Simulink and preliminary results of circuit experiment.