A rotor radial displacement observation method of bearingless flux switched motor based on space symmetrical flux sum of winding

Abstract

The invention relates to a method for observing the radial displacement of a rotor of a bearingless flux switching motor based on the sum of space symmetrical winding flux linkage. The method comprises calculating the flux linkage of the phase winding of the bearingless flux switching motor by using the detected voltage and current of the phase winding of the bearingless flux switching motor; calculating the sum of two winding flux linkages with 180 degrees spatial symmetry; Transforming the sum of each pair of winding flux linkages with spatial symmetry in a natural coordinate system to a rectangular [alpha][beta] coordinate; according to the relationship between [alpha][beta] coordinate system flux linkage and rotor radial displacement [detal]x, [detal]y, observing the rotor radial displacement [detal]x, [detal]y is observed. The invention does not increase the manufacturing cost of the motor and the control, the radial displacement of the rotor can be observed by utilizing the winding voltage and the current of the motor and the tangential position angle of the rotor.

Description

technical field [0001] The invention relates to the field of radial displacement measurement of the rotor of a bearingless magnetic flux switching motor, in particular to a method for observing the radial displacement of a bearingless magnetic flux switching motor rotor based on the flux linkage sum of spatially symmetrical windings. Background technique [0002] The bearingless flux switching motor adopts the stator permanent magnet structure, which is conducive to the heat dissipation of the permanent magnet. It has the outstanding advantages of high efficiency, reducing the risk of demagnetization of the permanent magnet due to temperature rise, and no pollution. It is used in high-speed, ultra-high-speed, large-capacity, clean It has extremely high application value in the field of motor drive. [0003] In order to realize the stable suspension of the rotor in the center, it is usually necessary to control two radial displacement degrees of freedom. In order to realize ...

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Problems solved by technology

[0004] The advantage of using a physical radial displacement sensor is that it can directly and quickly obtain the radial displacement of the rotor; but there are also obvious disadvantages: (1) Generally, the differential method is used to measure the radial displacement of the rotor, so measuring the radial displacement of one end of the rotating shaft requires 4 A displacement sensor, and the measurement accuracy of the sensor can distinguish the micron level, thus the cost of radial displacement detection is significantly increased, the cost of the bearingless motor and its drive system is increased, and the expansion of the practical application field of the bearingless motor drive system is limited; ( 2) Due to the installation of the bracket and the reference ring in the axial direction, the length of the rotating shaft is increased, the weight of the rotor is increased, and the critical speed of the rotor is reduced, thereby limiting the increase of the upper limit of the operation of the rotor in the high-speed area and the increase of the motor power, and also makes the motor The design is complicated; (3) The connection wire of the weak current signal is required between the radial displacement sensor and the controller, which reduces the reliability of the bearingless motor drive system, especially when the motor rotor is in high-speed suspension operation. If the position detection channel is faulty, there may even be major catastrophic consequences; (4) Since the end face of the radial displacement sensor and the end face of the reference ring have a certain area, there is an inevitable interference component in the radial displacement of the rotor detected by the sensor

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