An adaptive phasor estimation technique based on LES method using forgetting factor

This paper presents an adaptive data window algorithm for fast and accurate fundamental phasor estimation of voltage and current signals. The proposed approach is based on weighted least error square method. A forgetting factor is used to weight the older samples with smaller values in cost function computation. Thereby, the digital filters inertia would be reduced, which provides faster dynamic response in comparison with conventional full-cycle Fourier method. The proposed algorithm does not completely remove the older samples from the data window and therefore it provides more stable response compared to other variable length data window algorithms. Various simulation studies are carried out using different test signals as well as a power system model to demonstrate the effectiveness of the proposed method for relaying applications.