No abstract

No abstract

In this paper, the detent force caused by the end effect in a flux-switching permanent magnet linear motor (FSPMLM) with 6 slots and 5 poles is investigated and reduced by two different methods. Firstly, the detent force is diminished by adjusting the position of end teeth of primary side and injecting compensation current into compensation windings wound around the end teeth. Based on the linear relationship between compensation current and compensation force, the proper compensation current is derived and analyzed. Then, to avoid the magnetic coupling between compensation windings and phase windings, a novel compensation module with independent magnet circuit is presented and attached to the primary side of FSPMLM. Thirdly, the two detent force reduction methods are compared with each other, and the compensation module is proved to be more effective. Finally, a prototype of FSPMLM with compensation modules is manufactured and tested to validate the proposed compensation method. Index Terms-Flux-switching linear permanent magnet motor (FSPMLM), detent force, compensation coil, compensation module. I. INTRODUCTIONINEAR MOTORS possess several advantages such as rapid dynamic response, high precision, excellent reliability and quiet operation. Therefore, this kind of motor is greatly required in the occasions where linear motion is needed, such as rail transit, ropeless elevator, and electromagnetic launch [1][2][3][4][5]. However, for the applications demanding extremely long secondary, such as rail transit and ropeless elevator, the conventional permanent magnet linear synchronous motor (PMLSM) is inappropriate, because large amount of expensive permanent magnets or copper windings are indispensable. Flux-switching linear permanent magnet motor (FSPMLM) is more appropriate for the long secondary occasions, because its permanent magnets and windings are all installed in the primary side. Its secondary side only consists Manuscript

The modular arc-linear flux switching permanent-magnet motor (MAL-FSPM) used for scanning system is researched in this paper by the finite element method (FEM). The MAL-FSPM combines characteristics of the flux switching permanent-magnet motor and linear motor and can realize the direct driving and limited angular movement. Due to the double salient effect, the cogging torque including slot torque and end torque is very high. In order to reduce the cogging torque, a method of magnetizing the permanent magnet in reverse direction combined with rotor segmentation is proposed. By means of the proposed method, peak-peak cogging torque and load torque ripple are reduced effectively. Besides, the smooth operation range and an average load torque of the motor are also optimized. The effectiveness of the method is verified by both 2D and 3D FE models.INDEX TERMS Modular arc-linear flux switching permanent-magnet motor, cogging torque, segment rotor, magnetization direction of permanent magnet, finite element.

No abstract