A precise calculation of power system frequency and phasor

A series of precise digital algorithms based on discrete Fourier transforms (DFT) to calculate the frequency and phasor in real-time are proposed. These algorithms, called the smart discrete Fourier transforms (SDFT) family, not only keep all of the advantages of DFT but also smartly take frequency deviation and harmonics into consideration. These make the SDFT family more accurate than the other methods. Besides, the SDFT family is recursive and very easy to implement, so it is very suitable for use in real-time. The authors provide the simulation results compared with conventional DFT method and second-order Prony method to validate the claimed benefits of SDFT.