Measuring method and measuring apparatus of subsynchronous and supersynchronous harmonic phasors

The invention discloses a measuring method and measuring apparatus of subsynchronous and supersynchronous harmonic phasors. The method comprises the following steps: acquiring electrical signals so as to generate digital signals; performing filtering processing on the digital signals so as to obtain initial subsynchronous harmonic waves and/or supersynchronous harmonic waves; performing harmonic wave adaptive detection through DFT or FFT so as to obtain an initial frequency; according to the initial frequency, designing a filter so as to extract each subsynchronous harmonic wave and/or each supersynchronous harmonic wave; carrying out correction calculation by use of the phasor correction measuring algorithm so as to obtain the frequency, the amplitude and the phase of corresponding harmonic waves; and according to the gain and phase shift of the filter, performing amplitude compensation and phase compensation on the phasors so as to obtain a three-phase phasor of each subsynchronous harmonic wave and/or each supersynchronous harmonic wave. The measuring method provided by one embodiment of the invention can accurately measure the phasors of the subsynchronous and supersynchronous harmonic waves, thereby being applied to wide-area dynamic monitoring, analyzing, control and protection of subsynchrono resonance/oscillation of a power system.