Series connected forward-flyback converter for high step-up power conversion

This paper presents a newly-suggested high step-up topology employing a Series-connected Forward-FlyBack converter (SFFB), which has a series-connected output for high boosting voltage-transfer gain. SFFB is a hybrid type of forward and flyback converter, sharing the transformer for increasing the utilization factor. By stacking the outputs of them, extremely high voltage gain can be obtained with small volume and high efficiency even with a galvanic isolation. The separated secondary windings in low turn-ratio reduce the voltage stress of the secondary rectifiers, contributing to achievement of high efficiency. The single-ended scheme is also beneficial to the cost competitiveness.