Novel autonomous current mode one-cycle controller for PFC AC-DC pre-regulators

A new current mode autonomous one cycle controller is applied to a boost power factor correction AC-DC pre-regulator. The new controller has some advantages over the traditional current programmed (peak) controller and hysteretic controller. Meanly, the distortion near zero current crossing is avoided by a self increasing of the switching frequency in this zone. Simulation results show quasi-fixed switching frequency operation in steady state and spread spectrum in the frequency domain. In addition, the stability of the regulator is shown under a very high input-to-output voltage ratio condition that is difficult for conventional PWM controllers. Subharmonic oscillations can be therefore avoided without an extra ramp compensator.