Study of fuzzy PI controller in improving transient response performance of DC-DC converters

Abstract

To overcome the issues with classic linear PI control, such as the difficulties of modeling complicated control objects and the lack of experience in manual adjustment, a fuzzy PI control method for a double-closed-loop Buck converter system is developed. First, the current inner PI loop and voltage Fuzzy-PI outer loop structures are intended to operate simultaneously to enhance the system's immune performance; In order to increase the system's dynamic responsiveness, the subordinate triangle function is selected as the input and output subordinate functions. Following this, two subdatabases for PI parameters were established, and fuzzy rules for Buck converters were developed through a rule base based on expert experience, allowing the controller to be independent of the precise mathematical model of the Buck converter system and overcoming traditional PI control's drawbacks of high overshoot and output voltage oscillation; The reliability of the aforementioned proposition was lastly confirmed by a number of simulations and experiment.