Permanent-Magnet Eddy-Current Losses: A Global Revision of Calculation and Analysis

Ouamara, Daoud; Dubas, Frédéric

doi:10.3390/mca24030067

Cited by 25 publications

(14 citation statements)

References 149 publications

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“…Examining the bar chart presented in Figure 15, we may observe that over (nearly) the entire operational range, PM power losses are smaller in Motor #2; the difference is increased as rotational speed rises (this is true with exception of operating points at speed n = 1500 rpm and at loads up to T m = 150 Nm). Publications on the subject make it evident that decrease in number of slots per pole per phase results in increased PM losses [47]. Still, it must be pointed out that Motor #2 differs from Motor #1 by the number of magnetic pole pairs positioned upon diameter of similar size; this is related to significant decrease in PM angular length, so, finally, PM losses are lessened.…”

Section: Discussion Calculation Results-comparison Of Operational Parmentioning

confidence: 99%

Selected Aspects of Decreasing Weight of Motor Dedicated to Wheel Hub Assembly by Increasing Number of Magnetic Poles

Dukalski

Krok

2021

Energies

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Decreasing the mass of a wheel hub motor by improving the design of a motor’s electromagnetic circuit is discussed in this paper. The authors propose to increase the number of magnetic pole pairs. They present possibilities of mass reduction obtained by these means. They also analyze the impact of design changes on losses and temperature distribution in motor elements. Lab tests of a constructed prototype, as well as elaborated conjugate thermal-electromagnetic models of the prototype motor and modified motor (i.e., motor with increased number of magnetic poles) were used in the investigation. Simulation models were verified by tests on the prototype. Results of calculations for two motors, differing by the number of pair poles, were compared over a wide operational range specific to the motor application in the electric traction. A detailed analysis of the operational range for these motors was also made.

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Section: Discussion Calculation Results-comparison Of Operational Parmentioning

confidence: 99%

Selected Aspects of Decreasing Weight of Motor Dedicated to Wheel Hub Assembly by Increasing Number of Magnetic Poles

Dukalski

Krok

2021

Energies

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“…Surface charge density gradients generate gradients of electric field, and using square root scaled chart [64], it can be graphically evaluated for a conducting strip [65] and a bottleneck shaped sloppy conducting strip [66]. If reaction field is taken into consideration, the diffusion effect can be evaluated using MF method [40].…”

Section: Retaining Sleeve Winding and Eddy-current Reaction Fieldmentioning

confidence: 99%

“…For source terms, the assumption of balanced stator currents under steady-state operation are used to evaluate eddy-current reaction field. The balanced condition is not method-wise but needs to manipulate the diffusion equation into the Helmholtz equation form [11,39,40].…”

Section: Introductionmentioning

confidence: 99%

Improved Semi-Analytical Magnetic Field Solution for High-Speed Permanent-Magnet Machines With Permeable Retaining Sleeve Including Diffusion Effect

Mendonça¹,

Maia²,

Filho³

2020

PIER B

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This work presents a novel semi-analytical model for magnetic field calculation in a highspeed surface-mounted permanent-magnet machine with conducting and permeable retaining sleeve. The retaining sleeve with conducting material and non-homogeneous permeability affects the machine electromagnetic performance by altering main flux inductance and developed torque profile. This performance deviation can be attributed to eddy-current reaction field and saturation, the latter occurring due to pole-to-pole leakage flux. Saturation is modeled with a space-varying relative permeability, expressed as a Fourier series. Eddy-currents are evaluated with an auxiliary winding, defined as a surface current density in the conducting region. The proposed method is based on well-established Maxwell-Fourier method. This permits other analysis, such as slotting effect through subdomain technique. The assumptions considered for the developed semi-analytical solution in two-dimensional problem are presented in depth and confronted with finite-element method results, confirming validity of proposed methodology.

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“…In PM machines, the rotor losses are caused by a permeance variation of the airgap due to the slotting of the stator. When pulse width modulation (PWM) inverters are used for the excitation of PM machines, eddy current losses are produced by the switching harmonics of the PWM inverter [7], [8]. Hence, it is essential to diminish the spatial and time harmonics of the machine.…”

Section: Introductionmentioning

confidence: 99%

Analysis and Design of Novel High Speed Permanent Magnet Machine Considering Magnet Eddy Current Loss

Khan

Ahmad

et al. 2020

IEEE Access

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In high speed permanent magnet (HSPM) machines, the computation of magnet eddy current loss is essential as these losses significantly affect the temperature of the permanent magnet (PM) and electromagnetic performance and can result in irreversible demagnetization of the PM. Several techniques have been adopted to minimize the eddy current loss of the PM; however, superior performance has not been achieved yet. In this paper, the design characteristics of the HSPM machine are analyzed. The PM is covered by a titanium sleeve to retain the PM on the rotor and to further reduce the eddy current loss of the magnet. The undesirable harmonics of the airgap flux density are minimized, which reduces the eddy current loss in the solid PM and rotor. Two existing models, with and without auxiliary slots, are examined and compared with the proposed design having a titanium-based retaining sleeve. The analysis reveals that the eddy-current loss, cogging torque, and iron losses of the PM are reduced by 82%, 73%, and 44.7%, respectively, in the proposed model; however, a marginal increase is observed in the average rated torque profile and open circuit flux linkage.INDEX TERMS Auxiliary slot, eddy current losses, finite element analysis, high speed machine, iron loss, permanent magnet, sleeve, spatial harmonics.

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Permanent-Magnet Eddy-Current Losses: A Global Revision of Calculation and Analysis

Cited by 25 publications

References 149 publications

Selected Aspects of Decreasing Weight of Motor Dedicated to Wheel Hub Assembly by Increasing Number of Magnetic Poles

Selected Aspects of Decreasing Weight of Motor Dedicated to Wheel Hub Assembly by Increasing Number of Magnetic Poles

Improved Semi-Analytical Magnetic Field Solution for High-Speed Permanent-Magnet Machines With Permeable Retaining Sleeve Including Diffusion Effect

Analysis and Design of Novel High Speed Permanent Magnet Machine Considering Magnet Eddy Current Loss

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