Computationally Efficient Method for Identifying Manufacturing Induced Rotor and Stator Misalignment in Permanent Magnet Brushless Machines

Thiele, Mark; Heins, Greg

doi:10.1109/tia.2016.2552145

Cited by 26 publications

(19 citation statements)

References 22 publications

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“…Two types of static eccentricity appear in the literature [15,16]: the static angular and the static axis eccentricity. The first type occurs when the rotor axis coincides with the rotation axis but does not coincide with the stator axis.…”

Section: Types Of Eccentricitymentioning

confidence: 99%

“…During recent years, the demagnetization and the eccentricity fault have also been studied in the AFPM synchronous machine. More specifically [2,[8][9][10][11][12][13][14][15][16][17][18][19][20][21]] study the eccentricity fault, while [21][22][23][24][25][26][27][28][29][30] investigate the demagnetization fault in AFPM synchronous machines. In [31] a combined eccentricity and demagnetization fault in a double-sided AFPM synchronous machine using a time analytical model is presented.…”

Section: Introductionmentioning

confidence: 99%

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Study of a Combined Demagnetization and Eccentricity Fault in an AFPM Synchronous Generator

Barmpatza

Kappatou

2020

Energies

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This article investigates the combined partial demagnetization and static eccentricity fault in an Axial Flux Permanent Magnet (AFPM) Synchronous Generator. The machine is simulated using 3D FEM, while the EMF spectrum is analyzed in order to export the fault related harmonics using the FFT analysis. Firstly, the partial demagnetization fault, without the coexistence of eccentricity, and both the static angular and axis eccentricity faults, without the coexistence of partial demagnetization, are studied. In the case of eccentricity fault, the phase EMF sum spectrum has also been used as a diagnostic mean, because, when only eccentricity fault exists in the generator (either angular or axis) new harmonics do not appear in the EMF spectrum. Secondly the combination of partial demagnetization fault with static axis and static angular eccentricity is investigated and different comparisons are made when the demagnetization and the eccentricity level changes. The investigation revealed that the combination of eccentricity and demagnetization creates new harmonics in the EMF spectrum. The novelty of the article is that these combined faults are studied for the first time in the international literature, and the phase EMF sum spectrum has not been previously used for eccentricity diagnosis in this machine type.

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Section: Types Of Eccentricitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Study of a Combined Demagnetization and Eccentricity Fault in an AFPM Synchronous Generator

Barmpatza

Kappatou

2020

Energies

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“…Moreover, this term is valid for all IM machines with the same degree of eccentricity, except from a scale factor µ 0 lr g 0 (44). Besides, L rs = L sr , which makes unnecessary to compute (67).…”

Section: Numerical Computation Of the Phases Inductances In An Eccentmentioning

confidence: 99%

“…Despite its great accuracy, FEM models of an eccentric IM require important computer resources and computing time. To overcome this drawback, an hybrid FEM/superposition approach is proposed in [67], which is able to model an eccentric motor with a saving in time of several orders of magnitude, with a mere 3% of relative error compared with a full FEM model. In [33] a 3D field reconstruction method (3D-FRM)is applied to built stator and rotor basis using reduced number of FEM simulations, which provides the same accuracy as 3-D FEM at a lower computational cost.…”

Section: Introductionmentioning

confidence: 99%

Induction machine model with space harmonics for fault diagnosis based on the convolution theorem

Sapena-Bañó

Martínez-Román

Puche-Panadero

et al. 2018

International Journal of Electrical Power & Energy Systems

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Condition based maintenance systems (CBM) of induction machines (IMs) require fast and accurate models that can reproduce the fault related harmonics generated by different kinds of faults, in order to help in developing new diagnostic algorithms for detecting the faults at an early stage, to analyse the physical interactions between simultaneous faults of different types, or to train expert systems that can supervise and identify these faults in an autonomous way. To achieve these goals, such models must take into account the space harmonics of the air gap magnetomotive force (MMF) generated by the machine windings under fault conditions, due to the complex interactions between spatial and time harmonics in a faulty machine. One of the most common faults in induction machines is the rotor eccentricity, which can cause significant radial forces and, in extreme cases, produce destructive rotor-stator rub. But the development of a fast, analytic model of the eccentric IM is a challenging task, due to the nonuniformity of the air gap. In this paper, a new method is proposed to obtain such a fast model. This method, which is theoretically justified, enables a fast calculation of the self and mutual inductances of the stator and rotor phases for every rotor position. The proposed method is validated first using a finite elements method (FEM) model, and then, through an experimental test-bed using commercial induction motors with a forced mixed eccentricity fault.

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“…However, due to the smaller contact surface between the rotor and the shaft, it is more difficult to design a rotor-shaft mechanical joint with a high mechanical integrity [6], which makes AFPMMs more susceptible to imperfect assembly issues such as static eccentricities (SEs), dynamic angular misalignment [7] and static/dynamic eccentricity misalignment [8]. Under angular eccentric conditions, the rotor is inclined and the air gap is asymmetric.…”

Section: Introductionmentioning

confidence: 99%

Analytical Modeling of Static Eccentricities in Axial Flux Permanent-Magnet Machines with Concentrated Windings

et al. 2016

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Abstract:The aim of this paper is to calculate the static eccentricity (SE) of a double rotor axial flux permanent magnet (AFPM) machine by using a general analytical model. The flux density in the air gap under healthy conditions is calculated firstly, where the axial and circumferential magnetic flux densities are obtained using a coupled solution of Maxwell's equations and Schwarz-Christoffel (SC) mapping. The magnetic flux densities under SE conditions are calculated afterwards using a novel bilinear mapping. Some important electromagnetic parameters, e.g., back electromotive force (EMF), cogging torque and electromagnetic (EM) torque, are calculated for both SE and healthy conditions, and compared with the finite element (FE) model. As for the double rotor AFPM, SE does not contribute much effect on the back EMF and EM torque, while the cogging torque is increased. At each calculated section, FE models were built to validate the analytical model. The results show that the analytical predictions agree well with the FE results. Finally, the results of analytical model are verified via experimental results.

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Computationally Efficient Method for Identifying Manufacturing Induced Rotor and Stator Misalignment in Permanent Magnet Brushless Machines

Cited by 26 publications

References 22 publications

Study of a Combined Demagnetization and Eccentricity Fault in an AFPM Synchronous Generator

Study of a Combined Demagnetization and Eccentricity Fault in an AFPM Synchronous Generator

Induction machine model with space harmonics for fault diagnosis based on the convolution theorem

Analytical Modeling of Static Eccentricities in Axial Flux Permanent-Magnet Machines with Concentrated Windings

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