Abstract:
Various time domain, frequency domain and timefrequency domain methods have been used in literature for the
accurate phasor estimation in transmission-level PMUs. This
paper assesses the suitability of three such methods, viz., Taylor
Weighted Least Square (TWLS), Interpolated Discrete Fourier
Transform (IpDFT) and Empirical Wavelet Transform (EWT),
for developing the distribution-level PMU under steady state
and dynamic conditions, as per the IEEE C37.118.1a-2014. The
analysis is considered for fast phasor estimation by considering
one cycle observation window. The Total Vector Error (TVE) and
response time are chosen as performance metric. It is shown that
time-domain and frequency-domain methods, although have less
estimation error in case of fundamental phasor estimation and
comply with PMU Std. IEEE C37.118.1a-2014, except low order
harmonics and out of band interference case. However, in order
to estimate the harmonics along with the fundamental phasors,
time-frequency based method should be the preferred choice for
implementing the D-PMUs. The additional advantage of EWT is
to localize the dynamics of the signal in time-frequency plane.
