Permanent-magnet Halbach straight line motor

Abstract

The invention discloses a permanent magnet Halbach linear motor, comprising a primary iron core, a primary winding, a secondary Halbach permanent magnet and a secondary iron core, wherein, an air gap is reserved between the primary iron core and the secondary Halbach permanent magnet; the primary winding is wound on the primary core; and the primary winding passes through three-phase current. The permanent magnet Halbach linear motor also comprises an air gap compensation winding which is wound on the primary iron core in parallel with the primary winding and is connected with a control circuit. The air gap compensation winding can perform d-axis compensation through the control circuit to just offset the effect of armature current to the air gap, thereby effectively realizing the suspension control and stabilizing the height of the air gap. Because the air gap compensation winding is arranged, the permanent magnet Halbach linear motor can easily realize the suspension control of the air gap, and stabilize the height of the air gap while generating stronger suspending force and propulsive force.

Description

technical field [0001] The invention relates to a linear motor, in particular to a permanent magnet Halbach linear motor. Background technique [0002] Linear motor magnetic levitation technology is based on the interaction of electromagnetic force between the stator (primary) and the rotor (secondary). This interaction force is divided into the force in the traction direction and the force in the levitation direction. The levitation force is mainly provided by the secondary magnetic field, and the traction force is mainly generated by the three-phase current of the primary winding. [0003] The biggest feature of the linear motor is that there is no friction between the stator and the rotor, and there is no mechanical loss, so it can be applied to high-speed maglev trains, machine tool electrical, carrier-based aircraft launches, etc. In addition, many devices need to perform linear motion. Before the application of linear motors, they must be converted by intermediate mec...

AI Technical Summary

Problems solved by technology

Because the Halbach permanent magnet is placed inside the secondary rotor core, the permanent magnet is fixed well, so the requirement for the mechanical strength of the permanent magnet is relatively low, and it is easy to realize the field weakening control; the rotor of the built-in permanent magnet linear motor produces a sine wave excitation field, so that The rotor of the linear motor is suspended, and the rotor Halbach permanent magnet is made of rare earth permanent magnet material, which is composed of permanent magnets with different magnetization directions in an orderly manner, so that the magnetic field on one side of the permanent magnet is strengthened, and the magnetic field on the other side is weakened. Very strong magnetic field, while the magnetic field below is relatively weak; this permanent magnet linear motor can generate strong levitation force and propulsion force; the primary stator generates a traveling wave magnetic field after passing through three-phase alternating current, and after the interaction between this magnetic field and the excitation magnetic field , the electromagnetic thrust is generated to make the rotor part move linearly, the armature reaction generated by the primary stator armature current will change the air gap magnetic field, causing the levitation force to change, or the change of the rotor load will also cause the longitudinal resultant force to be unbalanced, so that The air gap of the rotor is highly unstable. In severe cases, the rotor cannot be suspended. Since the rotor is a permanent magnet, the magnetic field generated by it cannot be adjusted with external changes. Therefore, this problem cannot be solved, and it is not easy to achieve air gap suspension control. Stable air gap height

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