Abstract:Conventional proportional resonant (PR) controller is widely accepted and adopted in active power filters and inverters. But, the controller has an infinite gain at fundamental frequency, and the system stability is decreased. For improving the quality of current, a novel fuzzy PR control strategy for the Zsource inverter in threephase gridconnected system was proposed.In the controller, fuzzy logic control was combined with PR control; the selftuning of the fuzzy parameters was used in regulating the parameters of the PR controller. The system models and design procedure of the controller for Zsource inverter were also presented.Compared with conventional PR control strategy, the control strategy has more advantages such as its faster dynamic response, higher static tracking accuracy and better harmonic suppression. Simulation results were provided to verify the feasibility and effectiveness of the proposed approach.