Abstract— In this paper, nonlinear-carrier (NLC) control is
proposed for high-power-factor rectifiers based on flyback, Cuk, ´
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.
Index Terms—Current-mode