CN-115811156-B - High-power-density permanent magnet auxiliary synchronous reluctance motor and design method thereof

CN115811156BCN 115811156 BCN115811156 BCN 115811156BCN-115811156-B

Abstract

The invention relates to a high-power-density permanent magnet auxiliary synchronous reluctance motor which comprises a rotor and magnetic poles, wherein each magnetic pole comprises an outermost layer magnetic barrier and a corresponding permanent magnet, a U-shaped middle layer magnetic barrier and a corresponding permanent magnet, and a U-shaped innermost layer magnetic barrier and a corresponding permanent magnet. The permanent magnets of each layer are asymmetrically placed, the permanent magnets of the outermost layer are arc-shaped and are positioned on the left side, the lengths of the permanent magnets positioned on the left side of the U-shaped outer layer magnetic barrier and the U-shaped inner layer magnetic barrier are larger than those of the permanent magnets positioned on the right side, and the lengths of the permanent magnets positioned on the right side of the U-shaped outer layer magnetic barrier and the U-shaped inner layer magnetic barrier are larger than those of the permanent magnets positioned on the left side. The invention also provides a design method of the device.

Inventors

GUO LIYAN
SUN ZIHAN
WANG HUIMIN
WANG SIYUAN

Assignees

天津工业大学

Dates

Publication Date: 20260512
Application Date: 20221125

Claims (1)

1. A high-power-density permanent magnet auxiliary synchronous reluctance motor comprises a rotor and magnetic poles, wherein each magnetic pole comprises an outermost layer magnetic barrier and a corresponding permanent magnet, a U-shaped middle layer magnetic barrier and a corresponding permanent magnet, and a U-shaped innermost layer magnetic barrier and a corresponding permanent magnet, and is characterized in that the outermost layer magnetic barrier is embedded in an arc shape and embedded in the surface of the rotor, the permanent magnets of each layer are asymmetrically placed, the permanent magnets have two placement modes, the first one is that for all the magnetic poles, the permanent magnets of the outermost layer magnetic barrier are arc-shaped and are positioned on the left side, the lengths of the permanent magnets positioned on the left side of the U-shaped outer layer magnetic barrier and the U-shaped inner layer magnetic barrier are larger than the lengths of the permanent magnets positioned on the right side, and the second one is that for all the magnetic poles, the permanent magnets positioned on the right side of the U-shaped outer layer magnetic barrier and the U-shaped inner layer magnetic barrier are larger than the lengths of the permanent magnets positioned on the left side, and the key parameters in an improved structure are optimally designed by using a Taguchi method so that the key parameters in the improved structure can be optimally matched, and the following steps are achieved: 1) Determining an optimization variable of the Taguchi method according to the proposed improved structure, wherein the optimization target is that the electromagnetic torque is maximum and the torque fluctuation is minimum, and the constraint condition is that the dosage of the permanent magnets is not more than that of the permanent magnets of the motor before improvement; 2) Obtaining the influence of each optimized variable on electromagnetic torque and torque fluctuation and the relative importance degree of the influence by adopting average value analysis and variance analysis, and realizing the matching design of key structural parameters in an improved structure; For the first permanent magnet placement mode, the permanent magnets under the same magnetic pole are named as 1-5, the arc-shaped permanent magnet in the outermost layer magnetic barrier is a permanent magnet 1, the right side permanent magnet in the middle layer magnetic barrier is a permanent magnet 2, the left side permanent magnet is a permanent magnet 3, the right side permanent magnet in the innermost layer magnetic barrier is a permanent magnet 4, the left side permanent magnet is a permanent magnet 5, the lengths of the permanent magnets 2-5 are l 2 ~l 5 respectively, and the optimization variables are selected as follows, the variable A is the included angle between the inner side of the permanent magnet 1 and the positive direction of the X axis, the variable B is the included angle between the outer side of the permanent magnet 1 and the positive direction of the X axis, the variable C is the length l 2 of the permanent magnet 2, and the variables D and E are respectively: 。

Description

High-power-density permanent magnet auxiliary synchronous reluctance motor and design method thereof Technical Field The invention belongs to the field of motor optimization design, and particularly relates to a rotor structure optimization design method of a high-power-density permanent magnet auxiliary synchronous reluctance motor (PMSRM). Background The permanent magnet synchronous motor has the remarkable advantages of small volume, low loss, high efficiency and the like, and is widely applied to a plurality of fields of electric automobiles, aerospace, industrial production and the like. Permanent magnet synchronous motors, however, require the consumption of large amounts of rare earth permanent magnet material, which makes them costly and unstable in supply. To solve such problems, PMSRM, which is a small amount of permanent magnets, has attracted attention. PMSRM is composed of two aspects, namely permanent magnet torque generated by a permanent magnet and reluctance torque generated by different inductances of an alternating-current shaft and a direct-current shaft. Because PMSRM has relatively low permanent magnet torque and the utilization rate of the total torque to the permanent magnet torque and the reluctance torque is low under the traditional rotor structure, the power density of the traditional PMSRM is low. In order to increase the power density PMSRM, this can be achieved by increasing the maximum value of the permanent magnet torque, or by increasing the utilization of the torque components by the total torque. When the optimization design is carried out on each parameter of the motor, not only the mutual influence among a plurality of optimization variables is needed to be considered, but also the different performances of the motor are needed to be considered, so that a multi-objective optimization design method is generally adopted. The conventional multi-objective optimization design method mainly comprises a genetic algorithm, a differential evolution algorithm and an optimization algorithm based on particle swarm, however, the intelligent optimization algorithm has the problems of complex solving process, overlong solving time and the like. Correspondingly, the Taguchi method established by the doctor of the Xuan Yi of the Japanese field is a multi-objective optimization design method with low cost and high benefit, and the method can greatly reduce the test times, reduce the test cost and improve the design efficiency, and is widely applied to the field of motor design at present. Disclosure of Invention The invention provides a rotor improved structure for high power density PMSRM and a design method thereof. On one hand, the maximum value of the permanent magnet torque is improved by changing the linear magnetic barrier and the built-in linear permanent magnet at the outermost layer of each magnetic pole into an embedded arc, and on the other hand, the permanent magnet in the middle of the U-shaped magnetic barrier is asymmetrically arranged at two sides of the U-shaped magnetic barrier by asymmetrically arranging the embedded permanent magnet at one side of the arc magnetic barrier under the same magnetic pole, so that the offset of the permanent magnet torque is realized, and the utilization ratio of the total torque to the permanent magnet torque and the reluctance torque is improved. And the structure can increase the output torque without increasing the dosage of the permanent magnet. In addition, in order to achieve the best matching of key parameters in the improved structure, the key parameters in the proposed rotor structure are optimally designed by using a Taguchi method to realize further increase of output torque and reduction of torque fluctuation. The technical proposal is as follows: A high-power-density permanent magnet auxiliary synchronous reluctance motor comprises a rotor and magnetic poles, wherein each magnetic pole comprises an outermost layer magnetic barrier and a corresponding permanent magnet, a U-shaped middle layer magnetic barrier and a corresponding permanent magnet, a U-shaped innermost layer magnetic barrier and a corresponding permanent magnet, the outermost layer magnetic barrier is embedded in an arc shape and is embedded on the surface of the rotor, the permanent magnets of each layer are asymmetrically placed, the permanent magnets are in two placement modes, the first one is that for all the magnetic poles, the permanent magnets of the outermost layer magnetic barrier are arc-shaped and are positioned on the left side, the lengths of the permanent magnets positioned on the left side of the U-shaped outer layer magnetic barrier and the U-shaped inner layer magnetic barrier are larger than the lengths of the permanent magnets positioned on the right side, and the second one is that for all the magnetic poles, the permanent magnets of the outermost layer magnetic barrier are arc-shaped and are positioned on the right side, and the lengths of