Parameter estimation of harmonics-polluted single-phase grid voltage signal

Estimation of instantaneous phase and frequency of harmonics-polluted single-phase grid voltage signal have been studied in this paper. The proposed approach uses a frequency adaptive Luenberger-sliding mode observer. Using Lyapunov stability theory, a frequency adaptation law has been proposed. The proposed frequency adaptive observer technique is robust against various perturbations faced in the practical settings, e.g., discontinuous jump of phase, frequency and amplitude. Global stability analysis of the closed-loop observer has been performed. Experimental results demonstrate the effectiveness of the proposed technique over a state-of-the-art technique proposed in the literature.