PROJECT TITLE :

Low-Complexity Least-Squares Dynamic Synchrophasor Estimation Based on the Discrete Fourier Transform

ABSTRACT:

In this paper, the expressions for the phasor parameter estimates came back by the Taylor-primarily based weighted least-squares (TWLS) approach, achieved using either advanced-valued or real-valued variables, are derived. In specific, the TWLS phasor estimator and its derivatives are expressed as weighted sums of the discrete-time Fourier transform (DTFT) of the analyzed waveform and its derivatives. The derived expressions show that the TWLS algorithm is sensitive to lower order harmonics and interharmonics located shut to the waveform frequency when few waveform cycles are analyzed. Conjointly, the algorithm sensitivity to wideband noise is explained. The connection between the TWLS phasor estimator and also the waveform DTFT is then specifically analyzed when either a static or a second-order dynamic phasor model is assumed. Moreover, a easy and accurate procedure for evaluating the TWLS estimator of the dynamic phasor parameters is proposed. The derived expressions for the $64000-valued version are then approximated in order to reduce the specified computational burden therefore as to attain the simplified TWLS (STWLS) procedure. That procedure will be advantageously utilized in real-time low-value applications when the reference frequency employed in the TWLS approach is estimated in runtime to improve estimation accuracy. Finally, laptop simulations show that the phasor parameter estimates returned by the STWLS procedure when the waveform frequency is estimated by the interpolated discrete Fourier rework methodology go with the M-class of performance if an appropriate variety of waveform cycles is considered.