Design and analysis of SISO fuzzy logic controller for power electronic converters

Power converters are non-linear systems that usually employ linear controllers designed to offer good small signal performance at the nominal operating point. Yet, the converter's large-signal response is generally poor. Fuzzy logic controllers (FLCs) used in such cases improve the response, but their small-signal response is not as good as that of linear controller. In this paper, design of a SISO-FLC that offers good small and large-signal performance in a boost converter is presented. Besides reducing control complexity, the FLC offers better transient response in the converter than the linear controller. Simulation results are presented to show this. Using describing function method, the system stability margins are also analyzed.