An FPGA control application: Self-control of current and linear control of DC link of PFC

This paper presents an application control strategy for controlling the input current and DC link voltage of a single-phase voltage-doubler boost PFC (power factor corrector) implemented by FPGA. A sample of the input voltage, or any other current reference, is not necessary, since it is naturally used as reference for the current loop, through the power circuit. The model is more accurate, presenting fewer simplifications and taking better advantage of the natural characteristics of the converter, when compared to classic control, with better results, and many advantages, by simply using a proportional compensator. Some of the advantages of this strategy include greater robustness and simplicity, less susceptibility to noise and a smoother turn-on characteristic. For the voltage loop, although it presents a hyperbolic characteristic, a linearized model was applied, using similar compensator and obtaining even better results than for the classical control strategy. It presents also a natural feedback for the total output voltage and even for the voltage balancing. The FPGA used in the project is an ALTERA_reg Cyclone II EP2C35F672C6, presented on the kit DE2, which is a low-cost FPGA with low-consumption at a great speed.