Current Sharing Control Strategy of BFBIC-IPOP Photovoltaic DC Grid-Connected Converter

With the large-scale development and utilization of new energy, DC grid-connected converter has received extensive attention. DC grid-connected converter based on boost full-bridge isolated converter input parallel output parallel (BFBIC-IPOP) has high stability, high voltage gain, no voltage balancing problem and other advantages, but it faces the challenge of current sharing between modules. In this paper, based on duty ratio perturbation method, by introducing duty ratio increment, a duty ratio perturbation method considering multi-module current sharing is proposed, which can ensure that the system tracks the maximum power point of photovoltaic and takes into account the current sharing of sub-modules. This method simplifies the system circuit and can be used as a backup scheme when the current sensor fails. Taking three-phase BFBIC-IPOP as an example, a Matlab / Simulink simulation model is built to verify the feasibility of the proposed method.