FPGA-Based Control for a Boost PFC Converter with Improved Dynamic Performance

A field-programmable gate array (FPGA)-based digital control boost power factor correction (PFC) AC-DC converter with average current-mode control (ACC) and load-current-injection control is proposed to achieve high power factor and to improve dynamic performance. The ACC-controlled converter includes a fast inner current loop and a slow outer voltage loop. The current loop regulates the input current such that input average current follows the input voltage to comply with the current standards on power factor and input current distortion of power supplies. The outer voltage loop maintains the output voltage at a reference level against load variation and line voltage fluctuation. The main limitation of the ACC-controlled PFC rectifiers is that the bandwidth of the voltage loop is only about 10–20 Hz. The technique of load-current-injection control is applied to speed up the output voltage response to load variation. A 350 W prototype of boost PFC converter is built to validate the dynamic performance. The experimental results are provided to verify the high power factor complying with IEC 61000-3-2 Class D and fast output voltage regulation against the load variation.