Improved WLS-TF algorithm for dynamic synchronized angle and frequency estimation

This paper proposes an improved method for estimating synchronized angle and frequency under both steady-state and dynamic conditions based on the weighted least squares Taylor expansion Fourier (WLS-TF) method. The WLS-TF method using classical windows as weighting factors assumes the input signal is a narrowband band-pass signal, and it has efficient performance under most conditions. However, error arises when the signal is not a band-pass signal, which is the case for the waveforms of power system. This paper extends the band-pass signal model to a more general signal model that considers 2^nd order harmonic and proposes a new method to estimate the frequency. Examples of the proposed method are illustrated following different steady-state and dynamic conditions considered in power system.