Novel air gap magnetic field electromagnetic modulation permanent magnet motor with double squirrel cage structure

Abstract

A novel air gap magnetic field electromagnetic modulation permanent magnet motor with a double squirrel cage structure is a novel direct drive motor for directly realizing low-speed and high-torque output by means of electromagnetic modulation of high-speed air gap rotation magnetic fields, and can be applied to the transmission field of wind power generation, electric vehicles, ship drive and the like needing direct drive. The permanent magnet motor is characterized by comprising a stator with 2ps poles, an electromagnetic modulation hollow double squirrel cage rotor and a permanent magnet rotor with 2pr poles, wherein the stator, the electromagnetic modulation hollow double squirrel cage rotor and the permanent magnet rotor are of a radially concentric structure and have two air gaps respectively corresponding to two air gap rotation magnetic fields with different synchronous speeds. When running, three-phase symmetric alternating current flows through a stator winding 3 in the stator core 4 to generate the high-speed air gap rotation magnetic fields with fewer 2ps poles, the high-speed air gap rotation magnetic fields are modulated into high-order harmonic rotation magnetic fields with more 2pr poles by squirrel cages 13 of the hollow double squirrel cage rotor through electromagnetic modulation, and accordingly, the permanent magnet rotor is driven at a low speed and a high torque.

Description

technical field [0001] The present invention is a novel double squirrel-cage structure air-gap magnetic field electromagnetic modulation type permanent magnet motor, which is a new type of direct-drive permanent magnet motor that directly realizes low-speed high-torque output through high-speed air-gap rotating magnetic field through magnetic field modulation. It can be widely used in wind power generation, electric vehicles, ship drive and other industrial transmission fields that require direct drive. Background technique [0002] According to the theory of rotating electrical machines, in order for the motor to obtain continuous and stable load operation capability, the stator magnetic field and rotor magnetic field that generate electromagnetic induction must remain relatively static, which requires that the stator and rotor constituting the motor must maintain the same number of poles. In order to save raw materials, the motor It is often designed as a high-speed motor ...

AI Technical Summary

Problems solved by technology

This brings some indelible problems to the gear transmission, such as mechanical fatigue, friction loss, vibration noise, etc. Although the grease lubrication technology can be used, the above problems still cannot be eradicated, resulting in extremely cumbersome use and maintenance, and the mechanical gear transmission. The theoretical efficiency can only reach 85% at most. The mechanical gear pair transmission with fixed transmission speed ratio makes the structure of multi-stage and step-by-step speed regulation mechanism in a wider speed range complex, which cannot adapt to more and more continuously variable speeds. Transmission technical requirements

[0003] In recent years, with the development needs of new energy application fields such as wind power generation and electric vehicles, domestic and foreign countries have begun to achieve technical breakthroughs in new magnetic transmission technology for mechanical transmission. In 2004, British engineers completed the theoretical and practical prototype. The design work of a new type of radial magnetic gear has overcome the shortcomings of the previous permanent magnet gear with small transmission torque, which opens up an important research direction and future application field for the application of permanent magnet materials in the field of mechanical transmission; but The radial magnetic gear structure proposed by the British only uses the principle of heteropolar attraction of magnetic materials to construct a magnetic squirrel cage. The power transmitted by such a magnetic gear is only determined by the magnetic energy product of the magnetic material, so Although the torque and energy transmitted are improved, they are still limited by the magnetic energy product

In 2010, the national "863" high-tech project (2007AA05Z233) undertaken by Shanghai University in China also proposed a design scheme integrating magnetic gear transmission technology and permanent magnet motor and trial-produced the first composite motor prototype. This design scheme is only a simple integrated combination of the magnetic gear and the permanent magnet motor in structure. From the perspective of electromagnetic field theory, the magnetic circuit of the permanent magnet motor and the magnetic circuit of the magnetic gear are physically separated, so that the composite motor It has 3 air gap magnetic fields, which increases the unit consumption of expensive rare earth materials. From the perspective of motor drive, the above technical conception and design is simply a synchronous drive concept that uses magnetic materials as magnetic poles, so that the power transmitted by magnetic transmission The size is only determined by the magnetic energy product of the magnetic material, and it has not been considered in the structural design to increase the power transmitted by the magnetic gear by using the rotor squirrel cage self-induced current of the asynchronous motor to introduce asynchronous torque

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