A control architecture for low current distortion in bridgeless boost power factor correction rectifiers

Abstract

This paper presents a control architecture that substantially reduces current distortion in bridgeless boost power factor correction (PFC) rectifiers. In the proposed control architecture, the ac line voltage is sensed and the current reference is generated without rectification. This relieves the controller from having to deal with discontinuities around zero-crossing transitions, which eases requirements for the controller bandwidth and reduces distortion. Furthermore, a proportional-integral-squared (PI2) compensator is proposed to mitigate line current phase shift due to an input voltage feed-forward effect, which is particularly pronounced when a small boost inductance is employed. Very low distortion, near-ideal rectifier performance is experimentally verified on a 5 kW bridgeless boost PFC rectifier prototype.