Performance Comparison of Current Controllers with Harmonic Compensations for Single-Phase Grid Converter

The current control techniques developed on the basis of the internal model principle (IMP) are well suited for the single-phase photovoltaic systems. The main achievements of these controllers have been: sinusoidal grid current, unity power factor and high immunity to grid harmonic disturbances. Two ymain families of current controllers have been developed: the first based on the use of resonant controllers and the second based on the use of repetitive controllers. Similarities have been already individuated between these two classes of controllers, however many different implementation possibilities arise (use of selective, full, or any grid voltage feed-forward, implementation via the delta operator or zeta operator, etc.). This paper proposes an exhaustive comparison between these classes of controllers, full of insight judgment, and based on simulation and experimental results.