An input current shaping technique for PFC flyback rectifier by using inductor voltage detection control method

In this paper, the simplified current control technique using an inductor voltage control (IVD) method for power factor correction, PFC flyback rectifier is introduced. In the controller, the duty ratio is obtained by comparing a signal derived from the inductor voltage sensing of the power transformer with a negative slope ramp carrier waveform. The shape of the carrier waveform is determined from the relation of the rectified inductor voltage and the steady state DC conversion ratio of DC-DC flyback converter in the continuous conduction mode (CCM) by operating as a fixed switching frequency PWM controller. A simple ideal of negative ramp carrier waveform generator is described. Using the IVD controller, input line voltage sensing, error amplifier in the current shaping loop, analog multiplier/divider and current sensing are eliminated. To verify the ideal of the IVD controller, the circuit experiment has been applied to a 100 W flyback rectifier and its results are presented