Using RC Type Damping to Eliminate Right-half-plane Zeros in High Step-up DC-DC Converter with Diode-Capacitor Network

The novel DC-DC converter composed of an X-shape 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, two capacitors are naturally charged in parallel, and discharged in series. Thus, high voltage gain is achieved without extreme large duty ratio. Furthermore, the voltage stress of switching devices is reduced to a large extent. This paper makes detailed transient modeling of this topology through small-signal analysis and reveals the serious influence of non-minimum-phase system in high voltage gain application. To achieve good dynamic performance, RC type damping network is applied to eliminate the right-half-plane zeroes. Based on the model, advanced voltage loop feedback control algorithms for improving steady and transient performance is also presented. All the theoretical findings and design approaches are finally verified by simulations results. With some slight modification on the existing circuit, the new converter is very promising in renewable energy application.