Estimação de fasores harmônicos para PMUs baseada na interpolação B-Spline

Abstract

The estimation of the fundamental component is well known, mainly at the level of electrical energy transmission. For the advancement of monitoring technology of power systems, the phasor estimation of the frequency components in noise scenarios and frequency variations is still a challenge. This work has as objective the proposal of a methodology for estimating harmonic phasors that is applicable to phasor measurement units, discussing the issues involved in such a task. The proposed method comprises the following steps: estimation of the fundamental frequency, application of a B-Spline based resampling technique, extraction of the fundamental component with a Hanning filter, and finally calculation of the Fourier Transform. For the elaboration of the metodology were analysed the Lagrange, B-Spline and MSVA resampling techniques, as also frequency estimators based in zero-crossing, phase angle derivative and PLL. Thus, an optimized methodology was proposed in order to obtain the smallest error for harmonic phasors in terms of the total vector error (TVE), considering the low computational burden required. Different test scenarios suggested by the standard IEC 60255-118-1 were used in order to validate the performance of the proposed method.