Luenberger Observer Based Grid Synchronization Techniques for Smart Grid Application

Adaptive observer based grid synchronization technique has received wide attention recently. This technique has fast convergence property. However, adaptive observer is sensitive to unmodeled dynamics e.g. harmonics. Moreover, no small-signal models are available which can be useful for gain tuning purpose. To solve these issues, in this work, a harmonic robust adaptive observer is presented using the concept of in-loop filter. This improves the existing literature on adaptive observer based grid synchronization technique, which is the main novelty of this paper. To analyze the stability of the proposed technique, small-signal model of the adaptive observer with and without in-loop filter are presented. Finally, simulation study is presented to show the effectiveness of the proposed technique over two other advanced techniques from the literature.