A Novel Digital Controller for Boost PFC Converter with High Power Factor and Fast Dynamic Response

A novel digital controller for boost power factor correction converter is proposed to achieve high power factor and fast dynamic response. A method of direct duty cycle calculation is adopted to improve the power factor. The prediction module is adopted to estimate the track of the output voltage and the inductor current of next switching cycle in advance to improve the dynamic response. A multiplex successive approximation analog-to-digital converter (ADC) is designed to aim high resolution via little hardware resource. Meanwhile, a novel digital pulse width modulator (DPWM) is realized to improve the regulation linearity. The boost PFC converter with proposed digital controller based on the field programmable gate array (FPGA) has been implemented. Experimental results indicate that the proposed digital controller can achieve high power factor more than 0.98, the dynamic response under load variation is about 80ms and the output voltage overshoot is about 6%.