Active and reactive power regulation in single-phase PV inverters

Abstract

This work presents the design of a control to regulate the active and the reactive power in single-phase PV inverters. The control is composed by an inner loop with a passivity-based control in charge to track the current reference generated by the outer loop and PI controllers in the outer loop that regulate the power injection of the PV inverter. The passivity-based control ensures global asymptotic convergence of the tracking error to zero and the PV inverter shows robust current tracking with fast dynamics. Furthermore, a model of the overall control system is derived and the PI controllers parameters design guidelines which guarantee local asymptotic stability and robustness with respect to the unknown grid impedance are also provided. Numerical simulations when the power references, the PV irradiance or the grid impedance are changed validate the control performance.