Modular cascaded converter for MVDC-connected photovoltaic systems

This paper focuses on the relevant content of the MVDC-connected photovoltaic system based on the modular cascaded structure. This paper proposes a new topology for the DC grid-connected photovoltaic system with a novel capacitor voltage balancing control strategy, including the module input power ratio feed forward and module capacitor voltage closed-loop control. The proposed control strategy is independent from the realization of the photovoltaic maximum power point tracking function of the first stage. The operation principles of the proposed converter are analyzed and verified by the simulation and experimental results.