Robust control of boost PFC converter using adaptive PLL for line synchronization

The continuous development of the digital processing technology made advanced control strategies available for switched-mode power-supply applications. This paper presents the study and implementation of an adaptive Phased-Locked Loop (PLL)-based grid-fault tolerant control of a boost PFC converter. As the inductor current is synchronized to the rectified line voltage, by predicting the phase angle at each sampling sequence so the line current will follow the line voltage resulting in unity power factor. Tracking the phase angle of the rectified line voltage gives also the possibility to predict the next sampling value of the rectified grid voltage, avoiding in this way the compensation error caused by the delays of sampling and modulation. The proposed solution offers also noise immunity for the current controller to the line voltage disturbances.