Device for reducing cogging torque of permanent magnet motor, permanent magnet motor and method

Abstract

The invention discloses a device and method for reducing a cogging torque of a permanent magnet motor, and the permanent magnet motor. The method is characterized in that a permanent magnet unit is arranged on a rotor and comprises M sections of positive permanent magnets and N-M sections of negative permanent magnets; the M sections of the positive permanent magnets and the N-M sections of the negative permanent magnets are coaxially arranged on a same cylindrical surface in the axial direction; pole-arc coefficients of the M sections of the positive permanent magnets are set, so that cogging torques of the M sections of the positive permanent magnets are positive values in a first half cycle; and cogging torques of the N-M sections of the negative permanent magnets are set to be negative values in the first half cycle. The device and method and the permanent magnet motor provided by the invention have the advantages that the cogging torques generated by the sections of the permanent magnets offset one another, so that a total cogging torque of the permanent magnets is reduced; as initial phases of torques of the sections of the permanent magnets are identical or differ by 180 DEG, effects of the different pole-arc coefficients on a total output torque of the permanent magnets are small; and therefore, the technical problem of the conventional permanent magnet motor that the cogging torque of the permanent magnets and the effects on the output torque of the motor cannot be simultaneously reduced through skewing is solved.

Description

technical field [0001] The invention belongs to the field of motors, and more specifically relates to a device for reducing the cogging torque of a permanent magnet motor, a permanent magnet motor and a method. Background technique [0002] With the continuous improvement of the performance of permanent magnet materials, permanent magnet motors are more and more widely used in high-performance speed and position control systems. However, in permanent magnet motors, permanent magnets and slotted armature cores interact, inevitably Cogging torque is generated, resulting in torque fluctuations, causing vibration and noise, and affecting the control accuracy of the system. [0003] In order to solve the above problems, the prior art proposes various methods, such as figure 1 As shown, the permanent magnets are evenly segmented in the axial direction, and then the multi-segment permanent magnets are staggered by a certain angle in the circumferential direction, and the cogging t...

AI Technical Summary

Problems solved by technology

Its purpose is to solve the technical problem of large cogging torque pulsation in existing permanent magnet motors; the invention provides a device for reducing the cogging torque of permanent magnet motors, permanent magnet motors and methods, which can significantly reduce the cogging torque, At the same time, it does not affect the torque output of the motor

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