Sliding and fuzzy control of a boost converter using an 8-bit microcontroller

A two-loop control method for a boost converter, which combines fuzzy and sliding-mode methodologies, is presented. An inner loop controls the inductor current through a sliding surface whose reference signal is given by a slower outer loop. This outer loop employs a fuzzy logic mechanism to implement a PI controller that guarantees output voltage regulation and results in an excellent transient response during start-up. The controller implementation requires standard analogue devices for the inner loop and an inexpensive 8-bit microcontroller for the outer loop. Experimental results are in good agreement with the theoretical predictions and show a better dynamic performance than those obtained by means of classical analogue two-loop techniques.