Synchronized phasor measurement method for electrical power system based on cubic spline interpolation

The invention relates to the technical field of synchronized phasor measurement for an electrical power system and particularly relates to a synchronized phasor measurement method based on cubic spline interpolation. To the error problem of the traditional DFT method (Discrete Fourier Transformation) under non-synchronous sampling conditions of frequency deviation, firstly, a data window length is calculated according to constant sampling frequency and fundamental system frequency; secondly, the non-fundamental frequency integer multiple sampling time value is obtained through the cubic spline interpolation; finally, the synchronized phasor during the non-fundamental frequency integer multiple sampling time is obtained by Simpson formulas in the DFT method and numerical integration formulas. The method is higher in synchronized phasor measurement precision and excellent in synchronized phasor measurement noise immunity under the non-synchronous sampling conditions such as normal fluctuation and great deviation of the electrical power system frequency.