On the approximation of the state equations of nonlinear permanent magnet synchronous motors

Monitoring critical temperatures in permanent magnet synchronous motors is crucial for improving working reliability. Aiming at resolving the difficulty in online temperature estimation, an accurate and simple five-node lumped parameter thermal network (LPTN) is proposed and the mathematical model of the LPTN is built. Both radial and axial heat transfer paths inside the motor are considered to model the complete thermal circuit. In addition, an innovative parameter identification method based on multiple linear regression is applied to identify the parameters of the LPTN model. The parameters in the state equation are identified instead of the data of the motor, which are strongly dependent on the material and geometrical parameters. Finally, an open-loop estimation scheme based on the state equation and Kalman filter algorithm is adopted to predict the motor temperature online. The model performances are validated by extensive experiments under varying speed and torque conditions in terms of the accuracy and robustness. The results indicate that the temperature estimation error is within the range of ±5 °C in most cases and the proposed model can quickly follow the load variation. Besides, the online temperature estimation scheme and parameter identification method are easy and convenient to implement in an embedded system, which is feasible in automobile applications.

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Demagnetization fault diagnosis in permanent magnet synchronous motors: A review of the state-of-the-art

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2015.04.062 ◽

2015 ◽

Vol 391 ◽

pp. 203-212 ◽

Cited By ~ 37

Author(s):

S.S. Moosavi ◽

A. Djerdir ◽

Y.Ait. Amirat ◽

D.A. Khaburi

Keyword(s):

Fault Diagnosis ◽

Permanent Magnet ◽

State Of The Art ◽

The State ◽

Permanent Magnet Synchronous Motors ◽

Synchronous Motors

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Influence of unbalanced magnetic force on shaft deflection in permanent magnet synchronous motor with fractional slot concentrated windings

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209466 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 1461-1468

Author(s):

Ting Dong ◽

Juyan Huang ◽

Bing Peng ◽

Ling Jian

Keyword(s):

Permanent Magnet ◽

Magnetic Force ◽

Permanent Magnet Synchronous Motor ◽

Operational Reliability ◽

Topology Structure ◽

Permanent Magnet Synchronous Motors ◽

Synchronous Motors ◽

Shaft Deflection ◽

Large Length ◽

Fractional Slot

The calculation accuracy of unbalanced magnetic forces (UMF) is very important to the design of rotor length, because it will effect the shaft deflection. But in some permanent magnet synchronous motors (PMSMs) with fractional slot concentrated windings (FSCW), the UMF caused by asymmetrical stator topology structure is not considered in the existing deflection calculation, which is very fatal for the operational reliability, especially for the PMSMs with the large length-diameter ratio, such as submersible PMSMs. Therefore, the part of UMF in the asymmetrical stator topology structure PMSMs caused by the choice of pole-slot combinations is analysized in this paper, and a more accurate rotor deflection calculation method is also proposed.

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