Development of a Multivariable Deadbeat Controller in dq Coordinates for the Current Loop of a Grid-Connected VSI

One of the main concerns in designing control structures for Voltage Source Inverters (VSI) is ensuring the generation of sinusoidal currents that comply with international power quality standards. In this context, the present study investigates the evaluation of multivariable control techniques characterized by their Deadbeat nature, within coordinates dq. One of these techniques incorporates a virtual emulation of the current loop filter behavior. The application of these controllers is demonstrated in the context of a three-phase VSI connected to the electrical grid. These controllers not only show their effectiveness in decoupling control loops but also have greater stability without the presence of phase delays. With a specific emphasis on developing and fine-tuning multivariable Deadbeat controllers using dq coordinates, the study leverages three distinct models to analyze the stability and evaluate the performance of the control strategy. The synthesis of system models and consequently of controllers was made possible by the \(\alpha \beta \) $\alpha \beta$ and dq coordinate conversion method, developed in this study. This tool holds significant potential not only in synthesis but also in system analysis. The simulated solar setup uses a 5.1 kW photovoltaic system with second-generation modules. It includes an internal current loop, an external energy loop, and a multi-level VSI controlled by Space Vector Pulse Width Modulation (SVPWM). This complex combination of elements serves as the context for the tested control strategies, undergoing thorough testing and evaluation.