An AC voltage regulator with high-power-factor, and control using a FPGA device

This paper presents the analysis, design, simulation, and experimental results for a high frequency high power-factor (PF) AC (alternate current) voltage regulator, using a sepic converter as power stage. The control technique employed to impose a sinusoidal input current waveform, with low total harmonic distortion (THD), is the sinusoidal variable hysteresis control. The control technique was implemented in a FPGA (field programmable gate array) device, using a hardware description language (VHDL). Through the use of the proposed control technique, the AC voltage regulator performs active power-factor correction, and low THD in the input current, for linear and non-linear loads, satisfying the requirements of the IEC61000-3-2 standards. Experimental results from an example prototype, designed for 300 W of nominal output power, 50 kHz (switching frequency), and 127 Vrms of nominal input and output voltages, are presented in order to validate the proposed AC regulator.