Frequency-variable lifting device monitoring method and system, and mixing plant

The invention relates to the technical field of engineering machinery, in particular to a frequency-variable lifting device monitoring method, a frequency-variable lifting device monitoring system, and a mixing plant. The frequency-variable lifting device monitoring method comprises the following steps of: setting an optimal threshold area according to the current signal of a motor of a frequency-variable lifting device and the duration signal of the current signal; acquiring a real-time current signal of the motor, the parameters of a frequency converter of the frequency-variable lifting device and the duration signal of the real-time current signal; judging whether the real-time current signal and the duration signal of the real-time current signal are in the optimal threshold area; and if the real-time current signal and the duration signal of the real-time current signal are not in the optimal threshold area, modifying the parameters of the frequency converter to make the real-time current signal and the