A Multicarrier-PWM Scheme Along With a Reconfigurable Buck Converter Imitating Multiple Times Higher Switching Frequency

Abstract

This letter proposes a novel multicarrier pulsewidth modulation scheme and a reconfigurable dc-dc converter topology, which produces multiple times higher effective switching frequency than the actual switching frequency of the power devices. The reconfigurable topology incorporates multiple switches in series, and their gate pulses are generated using multiple modified and phase-shifted carrier waves. These switches operate alternately to multiply the operating frequency. Since the devices do not actually have to operate at high switching frequency, slower and cheaper power devices can be used. The resulting smaller filter requirement and cheaper power devices make the overall system compact and cost-effective. Moreover, the total switching losses in the proposed converter are distributed among a larger number of devices, which results in low switching loss per device. Consequently, the heatsink requirement comes down. The proposed scheme helps in developing a high-frequency switch mode power supplywithout the use of wide bandgap power devices. Nevertheless, combining the proposed scheme with silicon carbide and gallium nitride-devices can give tremendous enhancement in the operating frequency. The proposed concept has been explained and analyzed in detail and compared with the traditional schemes. Simulation and experimental results validate the concept.