Event-focused control strategy for a SiC-based synchronous boost converter working at different conduction modes

A SiC-based synchronous boost DC/DC converter rated for 400V to 800V and 10kW with high efficiency, especially at medium and light load, is designed and developed. The better switching performance of SiC MOSFETs allows the use of high switching frequency operation modes even at voltage close to 1kV (previously avoided due to the high switching losses introduced by silicon IGBTs). Evaluation of all the power losses in the converter for different conduction modes is fulfilled. Since the model of losses predicts suitable performance of QSW-ZVS conduction mode for low and medium loads, an event control strategy will be detailed taking advantage of digital control. This methodology will also allow self-regulating modifications of the operation mode in order to optimize the efficiency for different loads. Consequently, a control strategy based on events and switching among modes is proposed to maintain high efficiency in a wide power range.