Permanent magnet type motor modeling and demagnetization performance analysis method of asymmetric magnetic network

Abstract

The invention discloses a permanent magnet type motor modeling and demagnetization performance analysis method of an asymmetric magnetic network. The permanent magnet type motor modeling and demagnetization performance analysis method of an asymmetric magnetic network includes the steps: connecting a fixed permeance network model, an air gap permeance network model and a permanent magnet permeancenetwork model in series and in parallel according to corresponding positional relationships so as to be synthesized into a permeance network model of the entire motor; listing a node magnetic potential equation of the permeance network model of the whole motor, obtaining the magnetic flux of the permanent magnet through calculation according to a node magnetic pressure equation, and obtaining themagnetic density of any point of the permanent magnet through calculation; and determining demagnetization by comparing the magnetic density of the permanent magnet B(x) with the magnetic density B(X0) at the knee point X0 of the demagnetization B-H curve of the permanent magnet. Therefore, the permanent magnet type motor modeling and demagnetization performance analysis method of an asymmetric magnetic network can accurately analyze the demagnetization situation of the motor, can save the time, and can improve the design efficiency.

Description

technical field [0001] The invention relates to the field of motors, in particular to a method for analyzing the demagnetization performance of a permanent magnet motor. Background technique [0002] Permanent magnet motors are the main components of electric vehicles. Compared with electric excitation motors, permanent magnet motors use permanent magnets to generate magnetic fields. There is no electric excitation device, no excitation loss, simplified structure, and simple operation and maintenance. Permanent magnet motors use less permanent magnet materials to generate sufficient magnetic fields, are small in size, light in weight, high in power and high torque density, and have a wide range of constant power speed regulation. The air-gap magnetic field of the permanent magnet motor is generated by the permanent magnet. Due to its inherent characteristics, the permanent magnet material can establish a magnetic field in its surrounding space without additional energy after...

AI Technical Summary

Problems solved by technology

A demagnetization detection method for a permanent magnet brushless DC motor and a demagnetization detection device for a permanent magnet brushless DC motor are proposed in the literature with the Chinese patent application number 201510450719.X, the purpose of which is to propose a new permanent magnet The demagnetization detection scheme of the brushless DC motor solves the problem that it is difficult to detect whether the permanent magnet brushless DC motor is demagnetized, but it only detects and evaluates the demagnetization performance of the motor after the motor design is completed, and does not involve the study of the demagnetization performance of the motor. Does not analyze the effect of motor demagnetization on motor performance

However, since this method uses the traditional magnetic circuit method, the calculation accuracy is poor, and it cannot accurately analyze the demagnetization performance of the motor. In addition, the entire permanent magnet is equivalent to a network node in the magnetic circuit model, and the occurrence of permanent magnets cannot be considered. local demagnetization

Therefore, the accuracy of the calculation results is poor, which has a relatively large negative impact on the evaluation of the demagnetization performance of the motor and subsequent design corrections, and the analysis results have certain limitations.

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