Triple-Mode Current-Fed Resonant DC-DC Converter for Wide Input Voltage Range with Extended Asymmetric Modulation

This paper proposes a triple-mode current-fed resonant converter operating over a wide input voltage range for renewable energy systems. First, when the input voltage is lower than the nominal voltage, the proposed converter operates in a high boost mode. Next, when the input voltage is equal to the nominal voltage, it operates in a nominal boost mode. Last, when the input voltage is higher than the nominal voltage, it operates in a low boost mode. In contrast to conventional symmetric modulation techniques, this converter uses an extended asymmetric modulation technique that can lower hard switching turn-on loss. Accordingly, the proposed converter achieves high step-up ratio and power density over a wide input voltage range. A 400-W prototype is constructed and experimental tests were carried out to demonstrate the performance of the proposed converter.