Double-winding high-power-density hybrid excitation permanent magnet motor

Abstract

The invention discloses a double-winding high-power-density hybrid excitation permanent magnet motor which comprises a stator and a rotor, wherein the stator comprises stator yokes composed of a stator slot yoke and a stator back yoke; permanent magnets are arranged between the stator slot yoke and the stator back yoke; the stator slot yoke is positioned at the bottoms of stator slots in the direction close to the external circumference; the stator slots comprises slots, where armature windings are positioned, namely armature slots and slots, where exciting windings are positioned, namely excitation slots; the armature slots and the excitation slots are arranged alternately at intervals along the circumference; a set of armature windings are placed in the armature slots; a set of exciting windings are placed in the excitation slots. The motor can reduce the dosage of material and reduce the cost.

Description

technical field [0001] The invention relates to a permanent magnet motor, in particular to a double winding high power density hybrid excitation permanent magnet motor. Background technique [0002] In recent years, with the improvement of high temperature resistance and price reduction of permanent magnet materials, permanent magnet motors have been more widely used in national defense, industrial and agricultural production, and daily life, and are moving towards high power, high performance and miniaturization. direction of development. At present, the power of permanent magnet motors ranges from a few milliwatts to several thousand kilowatts, and its application ranges from toy motors, industrial applications to large permanent magnet motors for ship traction, and has been widely used in various aspects of the national economy, daily life, military industry, and aerospace. widely used. The main applications are as follows: [0003] (1) Household appliances: including ...

AI Technical Summary

Problems solved by technology

[0018] 1. Due to the fixed magnetomotive force of the permanent magnet in the existing permanent magnet motor, the main magnetic flux of the motor is not adjustable, resulting in a narrow constant power operating range and a wide range of speed regulation. In addition, the motor winding is generally 3 phases, the number of stator slots is large, and the lower winding complex line process

[0019] 2. 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

[0020] 3. 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 device. 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.

[0023] The other type is a structure in which the magnetic potential of the permanent magnet and the magnetic potential of the excitation winding are connected in parallel. This type of structure generally adopts the stator permanent magnet type. The permanent magnet is located on the stator, and the magnetic field is adjusted by adjusting the current of the excitation winding. After increasing the field winding, the number of motor winding sets is more, which makes the structure of the motor complex. Sometimes there will be multiple sets of windings in one slot or there are both phase windings and field windings. The phase-to-phase insulation needs to be added in the slot, and the winding off-line process Complicated, low slot utilization rate, and additional excitation slots are required, the mechanical structure of the motor is seriously fragmented, difficult to assemble and fix, complex processing technology, and high cost of the motor

More importantly, after adding the field winding, at least one more power switching device needs to be added to control the current of the field winding, which further increases the cost of the power circuit. Moreover, the magnetic flux generated by the field winding and the main flux share the main magnetic field. circuit and main air gap, the excitation effect is limited by other design parameters of the motor. Once the motor is manufactured, the excitation effect can only be controlled by adjusting the excitation current, and the excitation flux cannot be controlled by separately designing the excitation magnetic circuit.

Images