Independent Current Control With Differential Feedforward for Three-Phase Boost PFC Rectifier in Wide AC Input Frequency Application

Independent current control of the three-phase boost power factor correction (PFC) rectifier with differential feedforward is proposed for wide ac input frequency application. When conventional independent current control with proportional controller (P-controller) is used for digital-controlled three-phase boost PFC rectifier, the time delay of digital control brings phase leading of input currents. Such a phase leading is proportional to the ac input frequency. To achieve high power factor in wide ac input frequency application, differential feedforward is introduced to the input current control in the proposed control strategy to suppress the phase leading of input currents. The analysis and the design of the proposed control strategy are illustrated and a 2-kW experimental prototype is built to verify the analysis results. Experimental results show that the power factor of the three-phase boost PFC rectifier is improved significantly within wide ac input frequency range, e.g., 360–800 Hz. The proposed control strategy achieves satisfied performance when the ac input frequency varies.