Small-signal averaged model and carrier-based linear control of a new Sheppard-Taylor-based PFC

In this paper, the small-signal averaged model of a new Sheppard-Taylor-based DC-DC converter, used in single-phase power factor correction (PFC) applications, is derived. Compared to the conventional Sheppard-Taylor converter, this topology allows lower voltage stresses across the capacitors and larger output voltage range for the same operating area. Based on the proposed model, a carrier-based Pulse-Width-Modulation (PWM) linear control system is developed in order to ensure a unity power factor at the rectifier AC-side and a regulated voltage at the rectifier DC-side. Both current and voltage regulators are PI-type. The performance of the proposed control scheme is tested through simulations. The system performance is evaluated in terms of source current total harmonic distortion (THD), input power factor and DC-voltage regulation.