A High Power Density 75kVA Air-Cooled SiC Intelligent Power Stage (IPS) As A Universal Building Block for Grid Applications

With more and more power electronics-based resources and loads being integrated into the grid, there is a strong desire to standardize the grid power electronics building block to further reduce the cost. This paper presents the design and implementation of a high-power density, low cost air-cooled 75kVA SiC Intelligent Power Stage (IPS) as a possible solution for this purpose. The six-phase leg IPS is developed using discrete SiC devices, hence achieving very high power density and low cost. An intelligent gate driver is designed with integrated overcurrent protection, on-state voltage measurement, and temperature sensing functions to enable versatile and intelligent functionalities. The integrated auxiliary power supply is designed to start the system from both DC and AC sides. The IPS has built-in communication interface to communicate with other controllers to form a much larger and multiple converter systems and microgrids. The developed IPS is tested at 75kW in a two-stage DC-AC mode. The DC-DC stage is closed loop controlled by the local controller while the DC-AC stage responds to the modulation index from an external system controller. Measured full load two-stage power stage efficiency is 98.1% at 75kW.