Synchrophasor and frequency estimations: Combining space vector and Taylor-Fourier approaches

Taylor-Fourier (TF) filters represent a powerful tool to design PMU algorithms able to estimate synchrophasor, frequency and rate of change of frequency (ROCOF). The resulting techniques are based on dynamic representations of the synchrophasor, hence they are particularly suitable to track the evolution of its parameters during time-varying conditions. Electrical quantities in power systems are typically three-phase and weakly unbalanced, but most PMU measurement techniques are developed by considering them as a set of three single phase signals; on the contrary, this peculiarity can be favorably exploited. For the first time, in this paper, the TF approach is applied to the space vector obtained from three-phase measurements. The positive sequence synchrophasor can be easily extracted along with the system frequency and ROCOF leveraging the three-phase characteristics. Performance of the proposed technique is assessed by using test signals defined by the standard IEEE C37.118.1-2011. Results show that the positive sequence estimations are always more accurate when compared to the single-phase measurements provided by the conventional TF algorithms under the same conditions.