Nonlinear-Carrier Control for High-Power-Factor Rectifiers Based on Up~Down Switching Converters - Power Electronics, IEEE Transactions on

In this paper, nonlinear-carrier (NLC) control is proposed for high-power-factor rectifiers based on flyback, Ćuk, Sepic, and other up–down converters operated in the continuous conduction mode (CCM). In the NLC controller, the switch duty ratio is determined by comparing a signal proportional to the integral of the switch current with a periodic nonlinearcarrier waveform. The shape of the NLC waveform is determined so that the resulting input-line current follows the input-line voltage, as required for unity-power-factor rectification. A simple exponential carrier waveform generator is described. Using the NLC controller, input-line voltage sensing, error amplifier in the current-shaping loop, and multiplier/divider circuitry in the voltage feedback loop are eliminated. The simple high-performance controller is well suited for integrated-circuit implementation. Results of experimental verification on a 150-W flyback rectifier are presented.