Forward-Type Photovoltaic Three-Port Converter with Adaptive Resonance Time

This paper presents a forward-type three-port converter for standalone photovoltaic application. Specifically, the reuse of the bridge arm in the battery management structure shortens the power path of the battery port, and a current injection structure is introduced to achieve adjustable resonance for the resonant forward stage. Then, the gain adjustment range of the single-stage resonant forward converter is extended by precisely adjusting the phase-shift between the bridge arms. In addition, this improved design can accommodate over-voltage and under-voltage conditions during battery charging and discharging. Based on detailed theoretical analysis, experimental results confirm the effectiveness of the proposed strategy.