PWM boost converter with zero-voltage-switching

By adding a second transistor, a zero-voltage-switched (ZVS) quasi-resonant boost converter can be shown to be controllable using a constant frequency control scheme. The new topology differs from a zero-voltage-switched quasi-resonant boost converter by the addition of an extra switch in parallel with the resonant inductor. By adding a second switch, constant frequency control was achieved while still maintaining ZVS on both switches. The steady-state analysis of this new converter is derived. The converter characteristic curves are used to design an experimental prototype. The experimental prototype was built and tested to verify high-frequency/high-efficiency operation. It was operated at 610 kHz, 140 W, and 210 V output, and had a measured efficiency of 94.5%. This converter presents a feasible way to achieve both pulse width modulation (PWM) control and ZV soft-switching.<
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