Design of Automatic Fuzzy Control for Parallel DC-DC Converters

This study mainly focuses on the development of an automatic fuzzy control (AFC) system for a parallel dc-dc converter, and the control objective is to achieve the stable voltage regulation and uniform current distribution. The average model for an example of a three-module boost converter, which is composed of three conventional boost converter frames in parallel connection, is derived for the design of this AFC system including voltage and current control loops. In the voltage control loop, the target of the inductor current is designed to be followed by the current control loop, and the current control loop is designed via incremental fuzzy form to control respective duty ratios. In this AFC scheme, the fuzzy inference mechanism is automatically built according to inherent circuit properties without complex tuning algorithms or computation processes. The effectiveness of the proposed control scheme is verified by numerical simulations and experimental results. The advantages of good transient response and robustness to uncertainties are indicated in comparison with a conventional proportional-integral control (PIC) system.