FPGA-based single-phase PWM rectifiers with high power factor

This paper presents a new control circuit realization for the single phase pulse width modulated (PWM) rectifier bridge. A PWM control IC has been developed using the state-of the-art field programmable gate array (FPGA) technology. The FPGA chip with the on-chip analogue interface facilitates the use of high frequency digital modulation to regulate the input current and output voltage of the rectifier through the inner current loop and outer voltage loop control. This paper shows the feasibility of using FPGA for the digital control scheme to reduce the AC side harmonic currents and improve the power factor in the rectifier line current. The implementation of the digital controller and the performance characteristics of the controlled rectifier under different loading conditions are described. Experimental results presented in the paper confirm the high displacement power factor and the reduction of the line current harmonics.