Averaged small-signal modeling of a non-isolated single-stage single-switch AC/DC converter

A transformerless single-stage single-switch AC/DC converter was reported and analyzed recently. The converter features high power factor capability, high conversion efficiency, reduced voltage stress on bulk capacitor, low manufacturing cost and small in size. In this paper, its averaged small signal model is analyzed and presented for the control purpose. By applying small ac signal perturbations and statespace averaging technique, the crucial dynamic transfer functions are derived. Bode plots of the transfer functions are also given for designing the controller. The experimental results validate the model and show in good agreement.