Novel magnetic suspension bearing unbalanced vibration force direct inhibition method

Abstract

The invention relates to a novel magnetic suspension bearing unbalanced vibration force direct inhibition method. The novel magnetic suspension bearing unbalanced vibration force direct inhibition method comprises the following steps that step 1, a magnetic suspension rotor system model is established, and magnetic bearing current rigidity force and displacement rigidity force with the same frequency component are obtained; step 2, linear treatment is carried out on the obtained current rigidity force and the obtained displacement rigidity force to obtain unbalanced vibration force; step 3, atransfer function of synchronous rotation coordinate transformation is deduced; step 4, the same frequency component in the unbalanced vibration force is extracted; step 5, the same frequency component of the unbalanced vibration force obtained after the synchronous rotation coordinate transformation is directly used as a feedback compensation signal to be fed back to a power amplifier end of a magnetic suspension bearing control system; step 6, an analysis method containing a sensitivity function and a phase angle is adopted to analyze the stability of the whole magnetic suspension bearing unbalanced vibration force direct inhibition system. The novel magnetic suspension bearing unbalanced vibration force direct inhibition method is suitable for being used in a magnetic suspension bearingactive control system, and the unbalanced vibration force caused by unbalance of the mass of a rotor can be effectively inhibited.

Description

technical field [0001] The invention belongs to the field of active magnetic suspension bearing vibration suppression, in particular to a novel method for directly suppressing unbalanced vibration force of a magnetic suspension bearing. Background technique [0002] Magnetic levitation bearing has a non-contact support structure, has the characteristics of no need for lubrication, no friction, and can actively control the support stiffness, so it is widely used in high-speed motors, satellite attitude control, and molecular pumps. Residual unbalance, so its geometric principal axis and inertial principal axis do not coincide, causing vibration at the same frequency. The vibration is transmitted to the external equipment through the casing, which will cause serious interference and noise, especially at high speeds, which has a great impact on the operational reliability and precision of the magnetic suspension bearing. Therefore, the research on the suppression method of the...

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Problems solved by technology

The current control methods mainly include the least mean square algorithm, repeated learning algorithm, etc., all of which generate compensation signals with equal amplitude and opposite phase to eliminate the same-frequency current, thereby eliminating the same-frequency vibration force, but this method does not take into account the displacement load. Vibration caused by stiffness. In addition, the algorithm has a fixed step size, which cannot take into account the convergence speed and stability requirements of the system. It is only applicable at fixed speeds.

Shi et al. gave the least mean square algorithm, which generates a signal with the same amplitude and opposite phase as the vibration signal of the same frequency for compensation, but does not consider the influence of displacement stiffness force, and more importantly, it cannot satisfy the compensation within the full speed range. The effect can only take effect at a fixed speed

Bi et al. proposed a repeated learning algorithm to adaptively adjust the learning gain. Although it can meet the compensation effect in a large speed range, it still does not eliminate the same-frequency displacement stiffness force, but only eliminates the same-frequency current stiffness force.

In addition, none of the above methods can guarantee the stability of the system after adding compensation in the full speed range.

In addition, the same-frequency displacement stiffness force compensation can be added to the current loop, but the low-pass characteristics of the power amplifier will affect the feed-forward compensation effect of the same-frequency displacement stiffness force, and there will also be errors in the speed measurement, and the open-loop compensation phase Errors will accumulate over time and the compensation will be less effective

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