Estimation of fundamental power quantities in single-phase systems under dynamic conditions

Abstract

This paper deals with the estimation of the fundamental power quantities in single-phase system operating in dynamic conditions. To this aim, the TWLS-IpDFT algorithm is proposed. According to that algorithm, the parameters of the disturbing tones nearby the fundamental component are firstly estimated by the two-point Interpolated Discrete Fourier Transform (IpDFT) algorithm. Then these disturbances are removed from the original signal and the parameters of the fundamental component are estimated by applying the real-valued Taylor-based Weighted Least Squares (TWLS) algorithm to the residual signal. The effect of frequency uncertainty, wideband noise, and harmonics on the accuracy of the estimated fundamental power quantities is analyzed through computer simulations. Moreover, the accuracies of the TWLS-IpDFT, the classical two-point IpDFT and the three-point IpDFT algorithms are compared each other through extensive simulations under both steady-state and dynamic operating conditions.