Permanent magnet synchronous linear motor magnetic pole structure design method based on PWM thought

Abstract

The invention discloses a permanent magnet synchronous linear motor magnetic pole structure design method based on a PWM thought, and the method comprises the steps: applying the PWM thought to the optimization of a magnetic pole structure of a permanent magnet through an equal-area principle, and carrying out the design to obtain a permanent magnet synchronous linear motor magnetic pole structure comprising a plurality of permanent magnet arrays; in the permanent magnet synchronous linear motor magnetic pole structure, PWM pulse width modulation is carried out on a magnetic pole formed by permanent magnets by using an equal area method, the width of each permanent magnet is determined according to a PWM pulse width modulation result, a sine air-gap magnetic field is approximately generated by a plurality of permanent magnets with different widths, and the purpose of reducing electromagnetic thrust fluctuation is further achieved. The harmonic content of the air-gap magnetic field of the permanent magnet synchronous linear motor can be effectively reduced, the sine degree of the air-gap magnetic field is improved, thrust fluctuation is effectively inhibited, and the problem that the air-gap magnetic field of the PMLSM is non-sine is solved.

Description

technical field [0001] The invention belongs to the technical field of linear motors, and relates to a design method for a magnetic pole structure of a permanent magnet synchronous linear motor based on the idea of ​​PWM. Background technique [0002] Since the linear motor does not require an intermediate transmission mechanism, it can directly generate linear mechanical energy without energy loss in the intermediate link, and is widely used in systems that require linear motion. With the development of industrial technology, linear motors are playing an increasingly important role in the fields of CNC machine tools, industrial robots, and industrial automation. Permanent magnet linear synchronous motors (PMLSM) have broad application prospects. [0003] However, the permanent magnet synchronous linear motor also has the obvious disadvantage of large thrust fluctuations, which hinders the improvement of motion performance and the expansion of application fields. The air-ga...

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Problems solved by technology

[0003] However, the permanent magnet synchronous linear motor also has the obvious disadvantage of large thrust fluctuations, which hinders the improvement of motion performance and the expansion of application fields.

The air-gap magnetic field contains high-order harmonic permeance, which is one of the reasons for the electromagnetic thrust fluctuation of PMLSM. The air-gap magnetic field generated by the traditional permanent magnet arrangement is non-sinusoidal, which will generate a large number of harmonic magnetic fields.

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