ABSTRACT
Phasor measurement units (PMU) are an essential part of modern power system. Phasor of alternating signals is widely used in protection and control schemes of power network. The sampled data of voltage and current signal are processed continuously through phasor estimation algorithms to obtain phasor values at each instant. Digital relays and controllers utilize these phasor values for system operation and control. Phasor estimation techniques based on discrete Fourier transform, discrete Wavelet transform, and least square method are briefly presented and a comparative assessment has been carried out. The performances of phasor estimators have been evaluated based on ‘Total vector error’ and ‘Transient monitor’ criterion. The effects of noises, harmonics, and sampling frequency have been studied and results are shown and discussed. A two-terminal system has been considered for simulation under Matlab®/Simulink™ environment.
