Model analysis and intelligent-ANFIS control design for PWM-regulated ac/dc converters

A new design approach for nonlinear intelligent controllers for PWM-regulated ac/dc converters is proposed. First, the nonlinear model of the complete system is obtained, on which a passivity based analysis is conducted. Using this model, it is proven that the system always has the damping property independently from the controller scheme that one can apply. This is a significant contribution for fuzzy logic based intelligent control applications since it makes possible to overcome the inherent drawback of these designs, that is the ability to guarantee stability of the closed loop system. Thus, nonlinear adaptive neuro-fuzzy inference system (ANFIS) controllers are proposed to be used in order to obtain flexible, fast and efficient regulation of PWM-regulated ac/dc converters. The performance of the proposed ANFIS based controllers is simulated on a test system. The transient response of the proposed ANFIS controllers indicates an excellent performance which seems to enhance that of the conventional PI controllers.