Sensitivity analysis of weighted-least-squares dynamic phasor estimator to wideband noise

This paper investigates the influence of wideband noise on the accuracy of phasor, frequency, and Rate of Change Of Frequency (ROCOF) estimators returned by the Taylor Weighted Least Squares (TWLS) algorithm. Both static and dynamic operating conditions are considered, according to specifications of the IEEE Standard C37.118.1-2011 for synchrophasor measurements in power systems and its Amendment IEEE Standard C37.118.1a-2014. In particular, the effect on estimation accuracy of both the observation interval length and the number of acquired samples/nominal cycle is analyzed by considering as worst case the mean plus twice the standard deviation of the estimation errors. The achieved values are compared with the results achieved when processing noiseless waveforms and the thresholds specified in the above Standards documents. The performed comparison shows that the impact of wideband noise on the estimated phasor parameters can be relevant even though the signal-to-noise ratio is quite high.