A unity power factor control for fully software-controlled three-phase PWM rectifier with voltage link

A unity power factor control which is easy to implement with a single-chip microcontroller is proposed for a three-phase pulse width-modulated (PWM) rectifier with voltage link. When the conduction times of two adjacent space vectors are equally distributed at both sides in the middle of switching interval, the ripple of the sinusoidal waveform is reduced. Through steady state analysis, a condition for unity power factor is derived. DC output voltage and power factor are controlled by directly adjusting the phase of the rectifier input voltage. The proposed control scheme is easily implemented with a single-chip microcontroller. It is shown via experimental results that the proposed algorithms give good performance for the PWM rectifier with voltage link