Application of variable structure fuzzy logic controller for DC-DC converters

This paper presents a comprehensive study of different types of PID-like fuzzy logic controllers, such as fuzzy-P, fuzzy-PD, fuzzy-PI, and fuzzy PID, for application to DC-DC converters. Fuzzy-PI controllers are popular. However these generally give overshoot in output voltage and high initial current when rise time of response is reduced. A variable structure fuzzy logic controller (VS-FLC) is proposed in this paper to overcome these disadvantages of fuzzy-PI controllers. Computer simulations are performed to investigate the performance of the proposed variable structure FLC controller applied to a DC-DC converter system and better starting and steady state performance is obtained.