Sine wave current self-starting three-phase rare earth permanent-magnetism synchronous motor

Abstract

The invention relates to a sine wave current self-starting three-phase rare earth permanent-magnetism synchronous motor comprising a motor shaft (1), a rotor (3) and a stator (6), wherein the rotor (3) is arranged in the stator (6) and rotates around the motor shaft (1); the pole face of the rotor (3) comprises P pairs of poles, each pole comprises a pole arc face (302), and planes (301) are arranged between the adjacent pole arc faces. In the invention, each pole at the pole face of the rotor comprises one pole arc face, the planes are arranged between the adjacent pole arc faces, a non-uniform air gap is formed between the pole face of the rotor and the inner circle of the stator, and the asymmetry on a magnetic path, which is caused by a permanent magnet, is counteracted by utilizing the characteristic of a convex pole structure of the non-uniform air gap so that the structure of the rotor has simple manufacturing technology, the negative sequence component of the current of the rotor in the self-starting process of the motor is greatly reduced, the starting performance of the motor is enhanced, the motor can also have very good sine wave current in the running process, the harmonic loss is reduced and the efficiency of the motor is enhanced.

Description

Technical field [0001] The invention relates to a permanent magnet motor, particularly a self-starting three-phase rare earth permanent magnet synchronous motor with sine wave current. Background technique [0002] At present, the electricity consumption of various types of motors in our country has accounted for about 70% of the country's total power generation, and most of them are three-phase asynchronous motors directly running on the power grid. The actual operating efficiency is generally very low and the waste of electricity is very serious. Therefore, to grasp the energy saving of the motor is to grasp the key to energy saving. [0003] The stator structure of a self-starting three-phase rare earth permanent magnet synchronous motor is the same as that of an ordinary three-phase asynchronous motor. The rotor is equipped with a starter winding and high-performance rare earth permanent magnets. During the starting process, the starter winding generates torque to drive the mot...

AI Technical Summary

Problems solved by technology

Self-starting three-phase rare-earth permanent magnet synchronous motor, as one of the more complex types, has not made satisfactory progress

The main reason is that the current contains a lot of harmonics due to the unreasonable design of the magnetic circuit of the motor. On the one hand, this will affect the starting performance of the motor. Not well tapped and also a lot of harmonics in the current pollutes the grid badly

[0005] At present, although people have done a lot of work to improve and improve the structural performance of self-starting three-phase rare earth permanent magnet synchronous motors, they still cannot obtain a good sinusoidal current waveform, and the harmonic problem is still not fundamentally resolved.

For example, the invention patent 200710158557.8 "self-starting high-efficiency permanent magnet synchronous motor" and the utility model patent ZL200520100814.9 "new self-starting permanent magnet synchronous motor" have certain improvements and improvements in the structure and performance of self-starting synchronous motors, but neither of them can guarantee to obtain Good sine wave current, harmonic issues still exist

[0006] Another example is the new utility patent ZL00252876.2 "Sinusoidal Permanent Magnet Magnetic Flux Density Waveform Permanent Magnet Synchronous Motor", which achieves non-uniform air gap through the non-concentricity of the inner circle of the motor stator and the outer circle of the rotor, which can improve the magnetic flux density waveform, but cannot effectively improve the symmetry of the magnetic circuit Sex, can not get a better sine wave current

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