Design of digital controllers for DC-DC converters based on rough set theory

This paper investigates and proposes the use of the rough set theory as an innovative approach to digitally control static DC-DC converters. Rough set theory is a powerful mathematical tool which is able to produce a set of rules that represents the behavior of a certain system. PID and fuzzy controllers applied to the buck and boost converters, respectively, are used as model controllers. Each controller is implemented and tested and some of its signals are sampled to produce a database. A set of rules is derived from the application of rough set theory to this database. These rules are used to generate a digital controller - the RS digital controller which has a behavior similar to the model controller. The RS digital controller is then applied to the buck and boost converters. Theoretical aspects of rough set theory and the RS digital controller design are presented. Additionally, simulation results are provided and analyzed. They show the functionality of the RS digital controllers and validate the proposed approach.