Pages: 23 -34
H.Z.AZAZI, E. E. EL-KHOLY, S.A.MAHMOUD and S.S.SHOKRALLA
For digital power-factor correction (PFC) control methods, the duty cycle is calculated in every switching period. One main implementation barrier is the limited switching frequency, due to the limited processor speed. In this paper a predictive digital PFC control method is proposed to solve this problem. The proposed control method generates all the duty cycles in advance, based on the reference current and sensed inductor current, input voltage and output voltage. It requires only one multiplication and three addition operations for digital implementation, so that the proposed PFC control method can be implemented (by using a low cost DSP or microprocessor to achieve high switching frequency). A power factor correction rectifier, that requires a current control with a rectified sinusoidal reference, is controlled using three methods: i) Average current mode control ii) Hysteresis control iii) Proposed predictive control. All these controllers are implemented on a digital platform. Simulation and experimental results show that predictive control has low THD, high PF, lower cost and better performance than the others control methods (due to its lower calculation requirement). Also, sinusoidal input current can be achieved under a non-sinusoidal input voltage condition for predictive control only.