Estudos e contribuições para um gerador síncrono virtual com filtragem harmônica

Abstract

The high penetration of distributed generation units can decrease significantly the electrical system’s total rotational inertia and, consequently, deteriorate the system stability. In addition to this problem, the growing application of power electronics-based devices can introduce harmonic currents and voltages into the system and deteriorate the system’s power quality. This work proposes the study of inverter controls with synthetic inertia and harmonic compensation features. The virtual synchronous generator (VSG) controller determines the current reference at the fundamental component, which provides synthetic inertia to the inverter that contributes to the system stability, and the active filter controller calculates the reference harmonic currents to mitigate the harmonic currents and voltages in a power system. Thus, the combination of these two controls allows a single inverter to contribute to frequency stability and improve the power quality of an electrical system. The VSG model and harmonic detection strategies based on p-q Theory and linear Fourier combiners (FLC) are studied and, from these studies, controllers of an inverter that combine the VSG control and the harmonic detection strategy are proposed. Among the proposed combinations, the controller that combines VSG control with harmonic detection based on FLC with adaptive gain applied to an electrical system is the main contribution of this work. To verify the control strategies proposed in this work, simulations were carried out in software and experimental tests in software-in-the-loop platforms. From the results obtained in the simulations, it can be proved that the combination of the control of the virtual synchronous generator with the harmonic detection can simultaneously contribute to the stability of frequency and improve the power quality of the electrical system.