A real-valued Taylor Weighted Least Squares synchrophasor estimator

In this paper a real-valued version of the Taylor Weighted Least Squares (TWLS) algorithm is proposed. This algorithm can be considered as a generalization to both windowing and dynamic waveform model of the well-known three-parameter sine-fitting (3PSF) algorithm when the waveform offset is assumed to be null. The analytical expressions for the phasor, frequency, and Rate Of Change of Frequency (ROCOF) are derived. Several computer simulations performed under different steady-state and dynamic conditions compliant with the IEEE Standard C37.118.1-2011 about synchrophasor measurements for power systems and its related Amendment IEEE Standard C37.118.1a-2014 show that the real-valued and the classical complex-valued TWLS algorithms return the same results. However, the real-valued approach requires a lower processing effort. Furthermore, the accuracies of sine-wave amplitude and phase estimates returned by the real-valued TWLS algorithms as well as the 3PSF algorithm when the analyzed waveform is affected by different static or dynamic disturbances are compared by means of simulations. The achieved results show that the proposed algorithm provides more accurate results than both the classical 3PSF algorithm and its generalization based on data windowing.