An accurate small-signal model with peak current mode control applied for the Active clamp forward converter used in the constant conduction mode

In this paper, an accurate small-signal model with peak current mode (PCM) control for the Active clamp forward converter under continuous inductor current condition is proposed. To obtain this model, the “Ridely Approach” is utilized to derive the accurate Modulation gain, feedback gain and feed-forward gain in which the magnetizing inductance is fully taken into account. Clamp capacitor and magnetizing is another key factor effecting the small signal characteristic regarding the current loop, they are also been analyzed. To be more practical, the transient load response is given based on the closed output impedance transfer function to verify the derived model. Finally, the experiments are carried out and shown that the theoretical calculations match simulation result and experimental result very well. It is approved that the small signal mode proposed in this paper is accurate and can be applied in the practical power design to achieve better prediction result.