Modeling and controller design of high voltage gain DC-DC converter with multi-cell diode-capacitor network

Abstract

The novel DC-DC converter composed of multi-cell diode-capacitor network provides a simple solution for high step-up power conversion in renewable energy applications. With regard to the uni-directional power flow of the diodes, multi-capacitors are naturally charged in parallel, and discharged in series. Thus, high voltage gain is achieved without extreme large duty ratio of power devices. Furthermore, it does not increase the complexity of control circuit due to only one fully controllable power device. However, a lot of passive components increase the order of system model and complexity. This paper proposes a new modeling approach to get the reduced model for high voltage gain DC-DC converter with multi-cell diode-capacitor network. Then, the linear closed-loop controller is designed based on the reduced model in frequency domain. Finally, simulation and experiment are implemented to verify the correctness and effectiveness of the reduced-order modeling approach. And it contributes to the simplification of controller system, which is very promising in high voltage gain DC-DC converter with multi-cell diode-capacitor/inductor network in the renewable energy application.