Rapid harmonic wave analyzing method and device of power system

The invention provides a rapid harmonic wave analyzing method and device of a power system. The method includes a hanning window windowing processing, a combinatorial number FFT algorithm and an interpolation correction algorithm. The method includes the steps that firstly, hanning window weighting processing is conducted on a collected three-phase voltage signal and a collected three-phase current signal of the power system, then combinatorial number FFT conversion is conducted, and fundamental wave components and sub-harmonic components of the three-phase voltage signal and the three-phase current signal are obtained through interpolation correction. The device comprises a power signal acquisition conditioning circuit, an electric energy measuring ADE7878, a power supply, a central processor, a real-time clock, a NORFlash memory, an RAM memory and an SPIFlash memory, an RS485 communication interface, a programming switch and an electric energy pulse output interface. The ADE7878 is widely used in the aspects of electric energy data real-time collection and electric energy quality real-time monitoring, however, the data updating interval of the ADE7878 is 125 us, 160 signals are acquired in each period, and therefore a conventional base-2FFT cannot be conducted.