Technical Lecture Session
Control of DC-DC Converters
DSP, Control, dc-dc converters, resonant, quasi-square-wave
This paper presents an online optimization strategy for a SiC-based Boost converter that achieves quasi-square-wave ZVS transitions with minimal circulating currents. The proposed strategy dynamically adjusts the converter switching frequency and pulse-width dead times to optimally set the peak synchronous-rectifier (SR) turn-off current results in minimum-conduction QSW operation. A parametric curve-fitting technique accurately sets the optimal converter switching frequency and dead-times over full range of input/output voltages and load currents. These timing parameters are applied to the converter in a low-bandwidth feed-forward path in conjunction with closed-loop regulation. Experimental validation on a 5kW, 600V converter prototype demonstrates efficiency > 98%.