Modeling and control of a matrix converter using fuzzy supervisory controller

Matrix converter is a topology of direct AC-AC conversion converter. It provides a system of variable voltage and frequency from fixed input grid voltage. Therefore, the output of the matric converter is directly affected by unbalanced input grid voltage. Some research works have been made to overcome this problem by using Proportional integral (PI) control. However, PI control has limited performance when it is used in nonlinear systems. Fuzzy logic controller (FLC) has the advantage to control highly nonlinear and difficult to model systems. Therefore, the combination of these two controllers to form a fuzzy supervisory control (FSC) can give better performance to overcome the limitation of PI control in nonlinear systems. In this paper a novel FSC based control method is proposed. The FSC performs closed loop control of the output current to improve the performance of the MC powered by unbalanced grid voltage. The working principle, Venturini modulation strategy of MC and characteristics of FSC are presented. The performance of FSC is tested and compared for balanced and unbalanced grid.