Improved control of current controlled grid connected inverters in adjustable speed power energies

Abstract

This Paper presents a comparison of two control strategies applied to current controlled inverters in renewable energy systems. The strategies are the Synchronous Reference Frame and Stationary Reference Frame. First control method use PI regulators and it is the most used inverters control. In this paper, it is shown how to simplify the parameters design of the Proportional-Resonant controller for the Stationary Reference Frame. This paper presents the grid model and detailed design and stability analysis with a modified Symmetry Criterion method for the PI regulator parameters calculus. From this point, we transform the designed PI regulator into a PR, which it’s needed for the Stationary Reference Frame Control. Results in terms of THDi indicate the better performance of PR control.