Small Signal Analysis of a dual-switch forward Converter with non-ideal transformer in Current-Programmed Control

A small signal analysis approach of a dual forward converter with non-ideal transformer in current-programmed control (CPC) has been investigated in this paper. A small-signal model has been derived to determine the small-signal characteristics of the converter. By employing this model, the following significant features have been revealed or explained: (1) if the artificial ramp slop is properly selected, the ideal line-to-output transfer function of the converter becomes zero. That is to say, the output voltage fluctuation of causing from a perturbation of the DC bus voltage can be substantially restrained; (2) the CPC can greatly reduce the Q-factor and make the converter to become a low Q-factor system; (3) the current- programmed control can extend the bandwidth; (4) the magnetizing inductor plays an important role in the converter, so we must consider it when we design the control circuit.