Design and Implementation of Sliding Mode Fuzzy Controllers for a Buck Converter

Both fuzzy and sliding mode controllers have been utilized to regulate the output voltage of a buck converters in response to changes in the load and the input voltage. Although both control techniques possess desirable characteristics, they have disadvantages which prevent them from being applied extensively. Presented in this paper is a sliding mode fuzzy controller which combines the advantages of both fuzzy and sliding mode controllers. In addition, the sliding mode fuzzy controller is well suited for digital control design and implementation. A sliding mode fuzzy controller has been designed for a prototype buck converter and implemented on a TI TMS320F2812 DSP. The performance of the sliding mode fuzzy controller is evaluated through a comparison with an ordinary fuzzy controller and a linear PID controller. Based on this comparison, the sliding mode fuzzy controller is able to obtain the desired transient response without causing chattering under steady-state conditions