Modelling and control of Active Clamp Forward Converter with Current Doubler Rectifier

Small signal mathematical model, Open loop frequency response and closed loop analysis of Active Clamp Forward Converter with Current Doubler Rectifier (ACFC-CDR) in PSIM & MATLAB are presented in this paper. Forward converter includes a transformer to achieve galvanic isolation and to transfer energy. This converter consist of active clamp circuit to reveal energy stored in magnetizing and leakage inductance of transformer. Presence of clamp circuit in ACFC-CDR exhibits fifth order power stage dynamics. For full wave rectification, Current Doubler Rectifier(CDR) technique is implemented to the secondary side of transformer. State space averaging technique is applied to obtain a mathematical model of a power stage to analyze frequency response of open loop ACFC-CDR. Verification of mathematical model is achieved by comparing the results of open loop system in PSIM and MATLAB-Simulink also. Closed loop system analysis using Type III compensator.