Multilayer segmented built-in permanent magnet synchronous motor used for electric automobile driving

Abstract

The invention discloses a multilayer segmented built-in permanent magnet synchronous motor used for electric automobile driving. A built-in rotor part comprises a rotor iron core, a three-layer segmented neodymium-iron-boron magnetic steel and a magnetic barrier. By optimizing a pole-arc coefficient of every layer of a permanent magnet, the harmonic content of the gap flux density of the built-in permanent magnet synchronous motor is minimized, and therefore the torque ripple and the iron core loss of the built-in permanent magnet synchronous motor are reduced. By adopting the multi-layer mechanism, the salient pole rate of the motor reaches more than three, and the flux weakening capability of the motor is improved. Each permanent magnet is divided into four segments, and therefore the eddy current loss of the permanent magnet is reduced, the heating of the permanent magnet is reduced, and an anti-irreversible demagnetization capability is improved, and the reliability of the motor is improved. Compared with the prior art, the torque ripple and the iron core loss of the permanent magnet synchronous motor, and the permanent magnet eddy current loss are reduced, and the noises of the operation of the motor are reduced, and the operation efficiency and the reliability of the electric automobile driving motor are improved.

Description

technical field [0001] The invention relates to the technical field of synchronous motors, in particular to a multi-layer segmented built-in permanent magnet synchronous motor rotor with low air gap magnetic density harmonic content applied to the drive system of electric vehicles. Background technique [0002] Compared with internal combustion engine vehicles, electric vehicles have the advantages of high efficiency, no pollution, and low noise. The development of high-performance electric vehicles has been highly valued by governments, automobile manufacturers, and scientific research institutes of various countries, and they have formulated electric vehicle development plans one after another, setting off a global upsurge in the development of electric vehicles. At the same time, electric vehicles put forward higher and higher requirements for the efficiency, power density, cost performance and safety of the drive motor. The built-in permanent magnet synchronous motor is...

AI Technical Summary

Problems solved by technology

These low-order harmonics make the torque ripple larger and the motor noise larger when the motor is running at low speed

During high-speed weak magnetic operation, the stator core loss increases, the motor stator heats up seriously, and the efficiency decreases. It will also increase the eddy current loss of the rotor permanent magnet, increase the temperature rise of the permanent magnet, and increase the risk of irreversible demagnetization of the permanent magnet.

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