Research on Repetitive Control Method Applied to Grid-connected Inverter With LCL Filter

This paper discussed the limitation of the traditional control method for grid-connected inverters with an LCL filter.On this basis,the feasibility analysis on the application of the repetitive control method was carried out.Stability criterions,compensation methods,and the harmonic suppression ability were respectively analyzed in detail.Two different structures of the compound control method with both PI control and repetitive control were compared,and the advantages and disadvantages were concluded.All the theoretical analyses presented in the paper were verified by experimental results on a 3.7 kVA prototype of grid-connected inverters with an LCL filter.