A low-cost high-power density single-phase high-speed permanent magnet motor and method

Abstract

The invention discloses a low-cost, high-power-density, single-phase, high-speed permanent magnet motor and its method. Air slots are arranged inside the stator, and the air slots and armature slots are alternately arranged and evenly distributed on one side of the inner diameter of the stator core; the stator There is a permanent magnet slot for placing ferrite. The ferrite is arranged in a short-long-short manner to form a pole, which is distributed above the armature slot. The ferrite magnetization direction between every two adjacent air slots Same, one pole is formed, and the magnetization direction of the ferrite on both sides of the air groove is opposite; the rotor includes rotor teeth, rotor slots are provided between adjacent rotor teeth, and a main air gap is provided between the stator teeth and rotor teeth; Ferrites with the same polarity can achieve most of the magnetic flux passing through the main air gap through the cooperation of length and installation angle, so as to realize the magnetic gathering function and improve the performance and power density of the motor.

Description

technical field [0001] The invention belongs to the technical field of permanent magnet motors, in particular to a low-cost, high-power-density, single-phase, high-speed permanent magnet motor and its method. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art. [0003] High-speed fans, pumps and other load-driven occasions are widely used in various fields of the national economy, and a considerable number of fan and pump loads need speed regulation, so high-speed fans and pump drive motors are used in this field. been widely used in. In practical applications, different driving conditions of fans and pumps have different requirements on the performance of the driving motor. The traditional method is to achieve flow regulation through throttling devices, which is relatively simple, but will cause a large waste of energy. At the same time, due to the...

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Problems solved by technology

[0007] 1. The permanent magnets of most existing permanent magnet motors are located on the rotor and rotate with the rotor during operation. The permanent magnets need to be fixed by special procedures, and the manufacturing cost is high. Especially when the motor speed is high, it is more difficult to fix the permanent magnets. Located on the rotor, it is difficult to dissipate heat during operation, and the temperature rise and vibration caused by the rotation of the rotor will cause damage to the mechanical structure of the permanent magnet and irreversible demagnetization

[0008] 2. Existing permanent magnet motors are generally three-phase, and the power inverter circuit of the motor requires at least 6 power switching devices, such as IGBT or MOSFET, as well as the corresponding driving circuit and protection circuit for driving the power switching devices. The cost of the motor power inverter circuit is quite high, even reaching two to three times the cost of the motor body. The increase in the number of power switching devices increases the complexity of the control circuit, increases the possibility of device failure, and reduces the reliability of the system during operation.

[0009] 3. In addition, the existing permanent magnet motors mostly use distributed windings or concentrated windings spanning multiple pole pitches. Generally, the ends of the windings are long, the amount of copper used is large, the manufacturing cost is high, the copper consumption of the motor is large during operation, and the efficiency Low disadvantages, especially for motors with large outer diameter and small axial length, that is, a large ratio of diameter to length, this disadvantage is particularly prominent, and special winding coil connection methods are required to reduce the winding end and reduce the Use less copper to improve the efficiency of motor operation

[0010] 4. Permanent magnets with high magnetic energy product are generally required on the rotor, such as NdFeB. The practical engineering application of permanent magnet motor

However, the significant disadvantages of electrically excited switched reluctance motors are their large copper consumption and low efficiency.

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