Fixed-Frequency Current-Fed LCL Series Resonant Soft-Switching Converter With Capacitive Doubler

Electrification of power takeoff systems, which aims to cut down the fuel consumption of heavy-duty vehicles, needs a high voltage gain dc/dc converter with wide load and input voltage range soft-switching for high efficiency and high transformer utilization factor. Bulky input filter and transformer as well as complex frequency modulation limit voltage source resonant converters to suit such applications. The proposed current-fed series resonant converter eliminates these drawbacks. The resonant tank maintains tank currents, thus conduction losses, in proportion to the load demand to offer flat efficiency curve. On the other hand, the parallel resonant inductor can be designed to maintain wide load and input voltage range soft-switching. Also, simple pulsewidth modulation of the proposed converter at constant switching frequency complements its merits. This article presents the operation, analysis, modeling, and design of the proposed converter. Hardware setup has been mounted and tested to verify the proposed theory.