A Novel Deadbeat Control for Three-Phase Grid-Connected VSI with an Output LCL Filter in Natural Frame

A voltage source inverter (VSI) is a common solution in order to integrate distributed generation resources to utility grid. In this paper, by considering an LCL filter at the output of the three-phase grid-connected VSI, the system model is attained in the natural frame. Then, according to the achieved model, a novel deadbeat control is suggested to supply sinusoidal currents for being injected to the utility grid. Moreover, the considered method does not need transforming the system equations from the abc frame to another. The performance and feasibility of the suggested deadbeat control is evaluated in balanced, unbalanced and distorted grid conditions. The computer simulation results obtained from MATLAB/Simulink show that the suggested control demonstrates a good operation in reaching rapid dynamic response, closely zero steady-state error, closed-loop system global stability and also sinusoidal utility grid current including low total harmonic distortion (THD).