Concurrent and simple digital controller of an AC/DC converter with power factor correction based on an FPGA

Nowadays, most digital controls for power converters are based on DSPs. This paper presents a field programmable gate array (FPGA) based digital control for a power factor correction (PFC) flyback AC/DC converter. The main difference from DSP-based solutions is that FPGAs allow concurrent operation (simultaneous execution of all control procedures), enabling high performance and novel control methods. The control algorithm has been developed using a hardware description language (VHDL), which provides great flexibility and technology independence. The controller has been designed as simple as possible while maintaining good accuracy and dynamic response. Simulations and experimental results show the feasibility of the method, opening interesting possibilities in power converters control.

I. Introduction

The control of power converters is usually based on analog commercial solutions. In the case of power factor correction (PFC), the control is more complex because, in the general case, two loops are involved. Anyway, there are several analog commercial ICs solving this control problem. These circuits perform the basic control and their main advantages are low price and ease of use.