Subdomain Model for Predicting Magnetic Field in Slotted Surface Mounted Permanent-Magnet Machines With Rotor Eccentricity

Fu, Jiajing; Zhu, Changsheng

doi:10.1109/tmag.2011.2178250

Cited by 76 publications

(50 citation statements)

References 20 publications

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“…The ESA method works for radial or parallel magnetized magnets as well as for the overlapping or nonoverlapping stator windings [78]. In addition, the slotting effects [79,80] and different slot and pole combinations [81] can be considered in the SEA model. In a specific research, the five subdomains are often simplified.…”

Section: Exact Subdomain Analysismentioning

confidence: 99%

Review of Electromagnetic Vibration in Electrical Machines

Han

Chu

2018

Energies

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Electrical machines are important devices that convert electric energy into mechanical work and are widely used in industry and people's life. Undesired vibrations are harmful to their safe operation. Reviews from the viewpoint of fault diagnosis have been conducted, while summaries from the perspective of dynamics is rare. This review provides systematic research outlines of this field, which can help a majority of scholars grasp the ongoing progress and conduct further investigations. This review mainly generalizes publications in the past decades about the dynamics and vibration of electrical machines. First the sources of electromagnetic vibration in electrical machines are presented, which include mechanical and electromagnetic factors. Different types of air gap eccentricity are introduced and modeled. The analytical methods and numerical methods for calculating the electromagnetic force are summarized and explained in detail. The exact subdomain analysis, magnetic equivalent circuit, Maxwell stress tensor, winding function approach, conformal mapping method, virtual work principle and finite element analysis are presented. The effects of magnetic saturation, slot and pole combination and load are discussed. Then typical characteristics of electromagnetic vibration are illustrated. Finally, the experimental studies are summarized and the authors give their thoughts about the research trends.Energies 2018, 11, 1779 2 of 33 vibration mechanism can be helpful for the design of electrical machines. Therefore, the study of the electromagnetic vibration of electrical machines has practical significance.Electromagnetic vibrations are usually generated by the distorted air-gap field of an eccentric rotor in electrical machines. The uneven air-gap is directly related to the eccentricity, which is common in rotating electrical machines. Eccentricity can be caused by several reasons, such as relative misalignment of the rotor and stator in the fixing stage, misalignment of the load axis and rotor shaft, elliptical stator inner cross section, wrong placement or rubbing of ball bearings, mechanical resonance, and unbalanced loads [1,2]. Eccentricities can be further subdivided into two categories: circumferential unequal air gaps and axial unequal air gaps. The former can be grouped into static eccentricity and dynamic eccentricity. In the case of static eccentricity, the rotor rotates around its own geometric axis, which is not the geometric axis of the stator. In the case of dynamic eccentricity, the rotor is not concentric and rotates around the geometric axis of the stator. In reality, both static eccentricity and dynamic eccentricity tend to coexist. An inherent static eccentricity exists, even in newly manufactured machines, due to the build-up of tolerances during the manufacturing and assembly procedure, as has been reported in [3]. Unequal air gaps cause unbalanced magnetic forces (UMFs) [4] on the rotor, which lead to mechanical stress on some part of the shaft and bearing. After prolonged operation, these fac...

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Section: Exact Subdomain Analysismentioning

confidence: 99%

Review of Electromagnetic Vibration in Electrical Machines

Han

Chu

2018

Energies

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“…UMF is also caused by rotor eccentricity. The effect of rotor eccentricity is modeled in [42] by adding a first-order perturbation component to magnetic potentials, whereas [43] introduces it with a superposition method. For SCIM, it is possible to simulate defective bars as in [17] by decreasing their conductivity.…”

Section: E Current Applicationsmentioning

confidence: 99%

A review of subdomain modeling techniques in electrical machines: Performances and applications

Devillers

Besnerais²,

Lubin

et al. 2016

2016 XXII International Conference on Electrical Machines (ICEM)

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This paper reviews the recent developments of semi-analytical subdomains modeling techniques to compute the flux density distribution in electrical machines by the exact solving of Maxwell equations. It is shown that with an appropriate development methodology and numerical implementation, these harmonic models break the traditional compromise between accuracy and computation time that must be done using finite element or other analytical methods. Besides that, subdomains model development techniques have been improved to overcome its topological limitations This fact is demonstrated on three different subdomains models in comparison with finite element methods in terms of accuracy and processing time. The first one is a subdomains model of a surface permanent-magnet synchronous machine, the second one is for an inset permanentmagnet synchronous machine, and the third one is for a squirrelcage induction machine. Thanks to an efficient implementation method, a very low computation time is obtained. The robustness of the subdomains on the geometrical assumptions is also demonstrated.

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“…But a very few authors have analytically modeled any machine asymmetry. In [9], [10], the open circuit field for a machine with rotor eccentricity was presented. Qian et.…”

Section: Introductionmentioning

confidence: 99%

Analytical Prediction of Torque Ripple in Surface-Mounted Permanent Magnet Motors Due to Manufacturing Variations

Ortega

2016

IEEE Trans. Energy Convers.

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In the production of Surface-Mounted Permanent Magnet machines, manufacturing tolerances also contribute to torque ripple. Additional harmonics of low electrical orders are created in the torque spectrum. Slight manufacturing variations develop asymmetry conditions in the rotor as well as in the stator. Finite element models can be used to analyze the magnitude of pulsating torque generated due to these asymmetries. However, due to its random nature, lack of periodicity and symmetry, it is time consuming to study the problem with numerical methods for its uneven geometry that does not allow reduced geometrical models. Moreover, the experimental verification of all possible variations would be very challenging as it would require part dimensioning, part sorting, a large quantity of motor builds and finally testing of all samples. Therefore, in this paper an analytical model is presented to study the effect of such imbalance on the torque ripple. The model shows agreement against finite element models and also with experimental results when predicting torque harmonics that come from asymmetries.

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Subdomain Model for Predicting Magnetic Field in Slotted Surface Mounted Permanent-Magnet Machines With Rotor Eccentricity

Cited by 76 publications

References 20 publications

Review of Electromagnetic Vibration in Electrical Machines

Review of Electromagnetic Vibration in Electrical Machines

A review of subdomain modeling techniques in electrical machines: Performances and applications

Analytical Prediction of Torque Ripple in Surface-Mounted Permanent Magnet Motors Due to Manufacturing Variations

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