Single-phase unidirectional half-bridge converter with power factor correction

A novel single-phase half-bridge rectifier is presented to achieve power factor correction and harmonic current reduction. The circuit topology of the adopted rectifier consists of two power switches and two diodes. The unipolar PWM voltage waveform is generated on the AC terminal of the adopted rectifier. A carrier based current controller is used in the inner loop to achieve the power factor correction and draw a sinusoidal fine current from the mains. To maintain the DC-link voltage constant, a proportional integral voltage controller is adopted in the outer loop. A capacitor voltage compensator is employed in the proposed control algorithm to balance the neutral point voltage. To investigate the effectiveness of the proposed control scheme, experimental results are presented.