Quasi-proportional resonant control of the LCL-type grid-connected inverter based on fuzzy control and self-tuning of fuzzy parameters

This paper proposes the quasi-proportional resonant (QPR) fuzzy control of the LCL-type grid-connected inverter, which is based on 1) the inner-loop feedback control of the capacitor current and 2) the outer-loop QPR control of the grid-side current. Also, in the controller, self-tuning of the fuzzy parameters is used in regulating the parameters of QPR controller. The advantages of our methods are that: easy implementation, low computational cost, fuzzy control that is not dependent on rigorous mathematical models. Experiments show that this method has more effectiveness, compared with the usual proportional-integration controller and the quasi-proportional resonant controller.