Active Power Estimation in the Non-coherent Sampling: A Comparative Study

The paper presents and compares three basic approaches of the active power estimation of electrical systems under noncoherent sampling conditions when the leakage effect arises. The properties of the normal time domain approach with smoothing and summation and two frequency domain approaches with improved interpolated DFT estimations of the parameters are studied with respect to their systematic errors and effectiveness in leakage suppression. The simulations are presented showing advantages and weaknesses of compared methods in the shortening measurement time: between one and six cycles in the measurement interval. From analysis and experiments, it can be deduced that averaging of DFT coefficients around zero component provides the best estimation of the active power when the DC offset component is small enough