Measurement of magnitude and phase angle of voltage and current phasors and frequency deviation in power systems

摘要

Methods for determining magnitude, phase angle and frequency deviation in the sinusoid waveform output of electrical power generation equipment are disclosed. The first method uses a two-state linear Kalman filter to calculate the magnitude and phase angle from which the frequency deviation is calculated using the linear relationship between frequency deviation and the average rate of change of phase angle. In a second method, a three-state extended Kaman filter is employed. The frequency deviation is considered a third state variable and is recursively computed on-line.