Method and system for quickly governing inter-harmonics of fundamental frequency-variable power supply system

The invention relates to an inter-harmonic rapid treatment method for a fundamental frequency changing power supply system, and the method comprises the following steps: S1, collecting three-phase voltage and current signals of the power supply system, and calculating the real-time frequency and phase of the system; S2, performing fast Fourier transform on the current signal to obtain frequency, amplitude and phase data of fundamental waves and inter-harmonics of the current; S3, calculating to obtain a PWM control signal of a three-phase inverter switch required for generating inter-harmonicswith corresponding frequencies and amplitudes; S4, generating a three-phase harmonic current according to the frequency, the amplitude and the phase obtained in the step S2 through the switching action of the three-phase full-bridge inverter IGBT; and S5, sending the generated three-phase interphase harmonic current to a power supply system to counteract the interharmonic current generated by theload, and reducing the in