High performance two H-bridge in cascaded gradient driver design with SiC power MOSFET

In this paper, a detailed high efficiency two H-bridge in cascaded gradient driver design with 1700V SiC MOSFET is presented. Both module and system level stray inductance are minimized to better utilize the SiC high switching speed capability. The amplifier loss is calculated in simulation with device loss model and also verified in hardware experiment. The efficiency of the amplifier is higher than 99%. Higher output ripple frequency (up to 125 kHz) provides the opportunity to design a high density output filter without magnetic components. A novel ripple current cancellation circuit (RCCC) with embedded coolant pipe is also presented and demonstrated.