Power measurement in the non-coherent sampling

An algorithm to improve the estimation of the active power of electrical systems in the non-coherent sampling is proposed in this paper. It is based on smoothing the sampled data by windowing, and then averaging of the discrete Fourier transform (DFT) coefficients in the frequency domain to reduce the leakage effects. The simulation and experimental results are presented showing that averaging of the DFT coefficients provides better estimation of the active power then only by windowing. The use of a suitable algorithm depends on the positions of the frequency components, on a number of observed periods, and on the signal to noise ratio. (C) 2007 Elsevier Ltd. All rights reserved.