Robust repetitive feedback control of a three-phase grid connected inverter

This paper discusses the design of a repetitive feedback controller for a grid-connected two-level three-phase voltage-source inverter connected between a DC source and the grid through an LCL filter. The controller incorporates a classical two loop feedback of the output current and the capacitor current in addition to a repetitive feedback loop. The results show that the proposed technique improves the steady state error and the total harmonic distortion of output current in presence of utility harmonics.