High-Gain Four-Phase DC–DC Converter with Current and Voltage Self-Averaging Feature

A high-gain four-phase DC-DC converter is proposed, whose high voltage gain characteristic is suitable for applications such as photovoltaic generations, electric vehicles, energy storage system and so on. The proposed converter is improved from the traditional four-phase interleaved parallel DC-DC converter and has only three more capacitors than the traditional converter. The proposed converter has the voltage gain of about four times that of the traditional converter. When the output voltage is the same, the proposed converter has lower switching voltage stresses than the traditional converter. What's more, the proposed converter has current self-averaging and voltage self-averaging feature, which can make the proposed converter operating in open-loop controlled state without using inductor current sharing control and capacitor voltage balancing control. These features can also make the proposed converter operating in closed-loop control state only using one current sensor and one voltage sensor, which can save the design cost of hardware control circuit. Switching strategy, operating modes and steady state analysis are analyzed in more detail. Finally, a 300W, 24V-input to 200V-output prototype experiment is implemented.