Stationary Frame Current Control of Single Phase Grid Connected PV Inverters

For current regulation of single-phase grid connected PV inverters, many techniques like Predictive, non linear approaches and fuzzy based controllers have been applied so far, but each of them has their own drawbacks either because of requiring good knowledge of system parameters or difficulty in real time implementation. On the other hand despite the easy implementation of PI regulators, they also have well known disadvantage of having steady-state magnitude and phase error. In this paper a new control strategy aimed to mitigate this problems is proposed using frequency transform of a regular PI. The proposed current control strategy has been also experimentally tested with success on a 1.5 kW PV inverter