Control System Design for Grid-Forming Inverters in Grids with Background Harmonic Voltages

Grid-forming inverters play a crucial role in reinforcing weak utility grids by assisting in maintaining standard voltage and frequency levels. However, their effectiveness can be compromised in grids with prevalent harmonic voltages, leading to potential degradation of the injected current. This paper introduces a novel method to address this challenge by refining the conventional dual-loop control system employed in grid-forming inverters. The proposed approach showcases the inverter's capability to effectively inject power into a grid even in the presence of significant background harmonics. Through simulations, the study substantiates the effectiveness of this method, presenting compelling results that underscore its superiority over conventional approaches. This innovative solution holds promise for enhancing the resilience and performance of grid-forming inverters in grids with heightened harmonic challenges.