DC voltage sensorless single-phase PFC converter

We propose a simple dc voltage sensorless single phase PFC converter by detecting an ac line voltage waveform. Both dc voltage and ac current sensors used in the conventional PFC converter are not required to construct the control system. The conventional converter circuit with a boost chopper circuit in the dc side from a rectifier circuit is used as the main PFC converter circuit. In the control system, the circuit parameters such as a series inductance L and equivalent load resistance value R-d are used to generate the sinusoidal current waveform. The dc voltage is directly controlled by the command input signal k(d)(= E-d/E-a) for the boost chopper circuit. The dc voltage regulation is small because of the feed forward control for the ac line voltage E-a and no dependence of the circuit parameters. The sinusoidal current waveform in phase with the ac line voltage can be obtained. The feasibility of the proposed control system is verified by some simulation and experimental results.