Research Of Single Phase Power Factor Correction

With the power electronics equipment widely used, vast harmonic and var inject into power system. Vast harmonic do harm to power system and electric appliance. To solve the harmonic"pollution", there has two fundamental ways: one is to install harmonic compensation equipment to compensate harmonic; the other is to reconstruct the power electronics equipment, which produces no harmonic.With the fast developing technology of green energy, an ever-enhanced attention has been focused to the PFC rectifier in the field of power electronics. It can achieve high power factor.The principle and circuit structure of power factor preregulator based on Boost circuit with average current control are introduced. A small-signal model of the boost power factor correction circuit is developed. The model is applicable for frequencies below the line frequency. The design of current-regulation inner loop and a voltage-regulation outer loop is provided and the function of feed-forward voltage divider filter is analyzed. The model has been verified by simulation with SABER. By using SABER PFC circuit with UC3854 is made up. The simulation results validate the design. The simulation results show that the proposed predictive strategy for PFC achieves near unity power factor which is more than 97%. Based on analog implementation, digital control PFC implementations with average current mode control have been explored, the power factor is 95%.Based on the design of PFC with average current control, peak current control, hysteretic control and one-cycle control are provided, focusing on the model of peak current control. The effects of slope compensation in peak current-mode control are discussed. Several methods are provided to solve the problem including startup inrush current and load over-current limiting.