Small‐signal model analysis and control design of a double‐ended forward converter in discontinuous‐capacitor‐voltage mode

A double‐ended forward converter with an input inductor–capacitor filter has inherent power factor correction (PFC) properties and continuous input current when operating in discontinuous‐capacitor‐voltage mode (DCVM). In this study, the minimum separable switching configuration modelling is applied to the proposed converter operating in DCVM to obtain a small‐signal model of the converter. The impact of the circuit parameters on the small‐signal characteristic are discussed in details. The difference between the small‐signal behaviour of the converter when operating as a DC/DC converter and a PFC converter is investigated. The modelling methodology is intended for the design of controllers in closed‐loop operation. A 100 W prototype is implemented to demonstrate the feature of the small‐signal behaviour.