A digital leading phase current reduction (LPCR) technique for CCM boost PFC in light load conditions

This paper proposes a leading phase current reduction (LPCR) technique in a continuous conduction mode (CCM) boost power factor correction (PFC) for light load power factor (PF) improvement. The proposed LPCR technique provides the corrected average inductor current reference and the modified duty ratio feed-forward (MDFF) technique which can cancel the effect of the phase lead currents resulting from the EMI filter and input capacitor. Moreover, the proposed LPCR also provides the optimal dead-zone from the corrected current reference and MDFF. Therefore, the proposed LPCR can improve the power quality and efficiency not only in high AC line voltage range but also in extreme light load conditions. The principle and analysis of the proposed LPCR are presented, and the performance and feasibility are verified by experimental results from 230 Vrms input and 750 W-400 V output laboratory prototype.