Design of a Robust Unbalanced Current Control of a Three-phase Grid-tied Inverter

A linear matrix inequality (LMI)-based robust control is discussed in this paper for a three-phase grid-tied inverter with L-filtered output under unbalanced grid situation. The controller of this proposed method consists of two parallel current control for positive and negative sequence signals. Uncertainty models are also considered in this paper to provide wider range of stability to the system. The efficacy of the proposed method is validated by simulation results using PSIM simulation tool with help of MATLAB for gain computing.