Novel digital-controlled transition current-mode control and duty compensation techniques for interleaved power factor corrector

A novel digital-controlled transition current-mode control technique for interleaved power factor corrector (PFC) is proposed in this paper. For the presented technique, the switching period to retain zero-current switching is predicted rather than sampling the current in real time. Moreover, the related turn-ON period is determined by the voltage controller. Therefore, neither zero-current detection nor high-frequency A/D converter for current sampling is required. Moreover, for interleaved topology with masterslave control, a new ON-time compensation technique is proposed to significantly improve the slave inductor-current distortion, and thereby, achieving current sharing control between phases. Experimental results derived from a DSP-based controller are presented for confirmation. The PFC is with 100 Vac/50 Hz input and 400 Vdc output. The power rating is 460 W. Experimental results show that the power factor is higher than 0.98, efficiency is greater than 96%, and the current sharing can be achieved by the proposed ON-time compensation technique. These results confirm the aforementioned claims very well.