Simple digital current control strategy for single-phase grid-connected converters

This study proposes a simple digital current control technique for single-phase grid-connected voltage source converters. Unlike conventional strategies, the proposed method does not require any proportional-integral or proportional-resonant controller, fictitious phase generation, reference frame transformation and decoupling network; thus, it has the advantages of simplicity and reduced computational efforts. The suggested digital technique only uses a simple proportional controller in its structure and can be directly implemented on available digital signal processors. A digital controller parameter design procedure is proposed which ensures stability and near-zero steady-state error under all circumstances. Simulation and experimental results confirm that the proposed technique provides a fast and accurate current tracking with minimum harmonic distortions.