An intelligent control approach for resonance damping in a grid-connected inverter system

Abstract

Photovoltaic power generation has transformed into the most reassuring strategy for power generation among the renewable sources in view of its intrinsic favorable circumstances. The significant snag that photovoltaic system poses like other inexhaustible sources is the power intermittency in regard to atmospheric conditions like irradiation and temperature. These photovoltaic systems are interfaced to the grid through filters via inverters to prevent harmonics getting in to the grid. Generally, inductor–capacitor–inductor filters are employed in grid-connected system, as they provide better harmonic attenuation than inductor and inductor-capacitor filters. However, they bring resonance as well as oscillations into the grid-connected system. So, in order to suppress the resonance that brings instability problems in the system, active damping control strategies are adopted. But these conventional active damping methods increase the complexity of the system as they need extra sensors. This article proposes a fuzzy logic control-based active damping method to ease the control activity. The proposed controller is contrasted with the injected grid current feedback controller to investigate the resonance damping and the stability of grid interfaced multilevel inverter with inductor–capacitor–inductor filter. When compared with the injected grid current feedback controller, the fuzzy logic control approach promises satisfactory performance based on harmonic content, resonance peak, and stability analysis. The compliance according to the industrial standard in terms of harmonics is met in this article and is duly documented within the manuscript. Simulation results verify the design strategies and the effectiveness of the proposed fuzzy logic control strategy.