A new predictive control strategy for power factor correction

A new predictive control strategy for PFC is presented. Its basic idea is that all of the duty cycles required to achieve unity power factor in a half line period are generated in advance by using a predictive algorithm. Based on the average output voltage in the previous half line period, the duty cycles in the current half line period can be calculated by the predictive algorithm, which is derived from the differential equations of boost topology. An optimization process is incorporated with the predictive algorithm to fine tune the parameter of model for the purpose of further reducing the harmonic current. Benefited from the proposed digital control strategy, the switching frequency of the PFC does not directly depend on the processing speed of the DSP. Simulation results show that the proposed strategy works well and unity power factor can be achieved with wide input voltage and load current variation range.