Digitally-controlled power factor corrector with interleave transition current mode control

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 master-slave 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 power factor corrector is with 100 V/AC 50Hz input and 400 V/DC 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 above-mentioned claims very well.