A magnetic steel built-in double U-shaped fractional slot concentrated winding permanent magnet motor

Abstract

The invention discloses a magnetic steel built-in double-U-shaped fractional slot concentrated winding permanent magnet motor. The motor comprises a stator and a rotor 6; the rotor of the motor comprises a rotor core, inner-layer magnets, outer-layer magnets and magnetic steel slots. And the inner-layer magnets and the outer-layer magnets, forming U-shaped structures, are distributed at the rotorcore part; each group of magnets comprises four magnets, wherein the four magnets include two radial magnets and tangential magnets; a magnetic bridge used for enhancing the mechanical strength of therotor is arranged between two adjacent magnets in each group of magnets; and with the width of the magnetic bridges properly set, the mechanical strength of the rotor of the motor can be ensured, andthe motor does not generate large magnetic flux leakage. Whether the magnetic bridges are located between the magnets or between the magnets and the outer circle of the rotor, the width of the magnetic bridges in the outer-layer magnets is greater than the width of the magnetic bridges in the inner-layer magnets. According to the magnetic steel built-in double-U-shaped fractional slot concentrated winding permanent magnet motor of the invention, the number of the layers of the built-in magnets is increased, and therefore, the reluctance torque of the motor is increased; and the segmented rotor is adopted, the pulsating torque and rotor eddy current loss of the motor are reduced.

Description

technical field [0001] The invention relates to the field of motors, in particular to a built-in permanent magnet motor with a double-layer magnetic steel structure. Background technique [0002] Compared with the surface-mounted permanent magnet motor and the built-in permanent magnet motor, the AC-D axis inductance is not equal, the motor has a larger reluctance torque, and the weak magnetic performance is better. However, if the magnet steel is built in, the rotor flux leakage of the motor will increase, and the air gap flux density will be low, which will reduce the torque / power density of the motor; Layer magnetic steel to reduce the d-axis inductance, increase the difference between the d-axis and q-axis inductance, increase the reluctance torque, and increase the torque / power density of the motor. [0003] Compared with the conventional single-layer built-in permanent magnet synchronous motor, the d-axis and q-axis inductance difference of the multi-layer magnet stee...

AI Technical Summary

Problems solved by technology

However, due to the large number of magnetic steel layers, the d-axis inductance is small, which will reduce the magnetic field weakening capability of the motor and reduce the wide speed operating range of the motor.

At the same time, due to the setting of the magnetic barrier, the mechanical strength of the motor rotor is usually reduced

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