Dynamic Harmonic Synchrophasor Estimator Based on Sinc Interpolation Functions

This paper introduces a new dynamic harmonic synchrophasor estimator (DHSE) based on the Shannon sampling theorem. Each dynamic harmonic phasor is modeled as a weighted sum of a series of sinc interpolation functions. Based on this, a bank of finite impulse response filters is designed. They are used to estimate not only the dynamic harmonic synchrophasor but also the harmonic frequency and rate of change of frequency (ROCOF). A model parameter is properly selected to adapt filters' passband and stopband performances for different order harmonics. Frequency responses and simulation tests are used to compare the performance of the DHSE and the Taylor-Fourier transform (TFT). The results show that the DHSE has lower passband ripples and higher stopband attenuation than the TFT. Moreover, under frequency deviation, harmonic oscillation, and frequency ramp conditions, the DHSE is more accurate than the TFT in dynamic harmonic synchrophasor, frequency, and ROCOF estimations.