Boost Converter with Main Switch Possessing ZVT and ZCT and Auxiliary Switch Possessing ZCS

Abstract

In this paper, a zero-voltage and zero-current transition (ZVZCT) boost converter is presented with a small number of auxiliary components, such as a resonant capacitor, a resonant inductor and an auxiliary power switch, to produce a main power switch with both zero-voltage switching (ZVS) and zero-current switching (ZCS). Furthermore, the auxiliary power switch also has zero current switching. In addition, a look-up table is employed to implement an auto-tuning technique to regulate the trigger position and turn-on time of the auxiliary power switch, to further improve efficiency, especially at light load, thereby making the overall efficiency of the converter present a horizontal curve. Moreover, in terms of the system control, the digital controller is implemented directly from the z-domain, and the field programmable gate array (FPGA) is utilized as the system control kernel to achieve a fully digitalized control system. The simulated results are used to demonstrate the feasibility of the proposed converter, whereas the experimental results are used to verify its effectiveness.