Averaged Model Based Control of a Sheppard-Taylor PFC with Nonlinearity Compensation

In this paper, a nonlinearity compensation control is developed and applied for the single-phase Sheppard-Taylor power factor corrector (PFC). Compared to conventional buck, boost or buck-boost PFCs, this topology allows a better current tracking at the AC side, with a relatively reduced voltage at the DC side. Based on the exact linearization of the converter's averaged model, and on the use of a fixed-frequency carrier to generate the Pulse-Width-Modulated (PWM) gate signal, the control system is designed to ensure unity power factor at the rectifier AC-side and regulated voltage at the rectifier DC-side. The performance of the proposed control scheme is tested through simulations, and evaluated in terms of source current total harmonic distortion (THD), input power factor and DC-voltage regulation.