Impact of Thermal Conductivity in Axial Direction on the Overall Thermal Model of High-Speed Synchronous Motor

Veg, Lukáš; Laksar, Jan

doi:10.1109/icelmach.2018.8506933

Cited by 7 publications

(6 citation statements)

References 18 publications

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“…Most prior works based on LPTN primarily focus on how to identify the thermal parameters. Veg and Laksar [23] established a seven-node LPTN for a high-speed permanent magnet synchronous motor and calculated thermal resistances and other parameters using heat transfer coefficients. The accuracy of this method based on the theoretical formula is limited.…”

Section: Related Workmentioning

confidence: 99%

End-to-End Differentiable Physics Temperature Estimation for Permanent Magnet Synchronous Motor

Wang,

Wang

2024

WEVJ

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Differentiable physics is an approach that effectively combines physical models with deep learning, providing valuable information about physical systems during the training process of neural networks. This integration enhances the generalization ability and ensures better consistency with physical principles. In this work, we propose a framework for estimating the temperature of a permanent magnet synchronous motor by combining neural networks with the differentiable physical thermal model, as well as utilizing the simulation results. In detail, we first implement a differentiable thermal model based on a lumped parameter thermal network within an automatic differentiation framework. Subsequently, we add a neural network to predict thermal resistances, capacitances, and losses in real time and utilize the thermal parameters’ optimized empirical values as the initial output values of the network to improve the accuracy and robustness of the final temperature estimation. We validate the conceivable advantages of the proposed method through extensive experiments based on both synthetic data and real-world data and then provide some further potential applications.

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Section: Related Workmentioning

confidence: 99%

End-to-End Differentiable Physics Temperature Estimation for Permanent Magnet Synchronous Motor

Wang,

Wang

2024

WEVJ

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“…The geometric parameters of the blades have a combined effect on the HTC in the endwinding region of rotating electrical machines. The studies in the domain of heat transfer analysis consider the HTC solely as a function of the air velocity in the end-winding region [1,8,[10][11][12][13][14]. Obtaining the air velocity value is impossible without the CFD calculations or measurements; thus, the link between the air velocity and the rotor rotational speed is still missing.…”

Section: Derivation Of the Generalized Analytical Modelmentioning

confidence: 99%

“…The complexity of the turbulent air behavior in the end-winding region, generated by the rotating parts, makes an accurate calculation prediction of the HTC value difficult. The use of the generalized equation formulation regarding the HTC calculation, i.e., Shubert's equation (Equation (6a)), has been proposed in the published literature [1,8,[10][11][12][13][14], while the calculation is still heavily dependent on the empirical correction factors, based on experience and measurements. The equation consists of two parts, representing the natural (free) and forced convection, the latter being a function of average air velocity in the endwinding region.…”

Section: Introductionmentioning

confidence: 99%

Thermal Effects in the End-Winding Region of Electrical Machines

et al. 2023

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The main heat transfer mechanism in the end-winding region of electrical machines is convection. In order to increase the air motion, the rotor is equipped with a series of blades. Their geometry is reflected in the fanning factor, i.e., the ratio between the rotor peripheral speed and air velocity. An accurate calculation procedure for the fanning factor has not yet been given. Knowing its value is crucial for the determination of air velocity and heat transfer coefficient (HTC), as the latter describes the end-winding heat removal capability. In this study, the convective heat transfer phenomena between the end winding and air inside the end-winding region were analyzed, with the heat generated only in the end winding, mimicked with a custom designed coil, and air moved by the blades. The analysis was performed by experimental testing and computational fluid dynamics (CFD) modeling. Measurements data were used to build a reliable CFD model. Further on, CFD results were used to derive a generalized analytical equation for calculation of the end-winding HTC, related to blade geometry and rotor rotational speed. The developed analytical model significantly improves the quality of real-time lumped circuit thermal modeling of electrical machines and, thus, enriches this field of science.

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“…A B Nachouane [9], analyzed and fitted Cf under different Ta caused by different angular velocity, linear velocity and air gap length, but the influence of axial ventilation on Taylor vortices has not been studied. According to the existing research results [11][12][13], researchers commonly use linear superposition to calculate total windage loss caused by axial ventilation and tangential friction, which brings errors.…”

Section: Introductionmentioning

confidence: 99%

Analysis of axial windage loss in air gap of high-speed motors under high Taylor number

Song

Cao

Zhong³

et al. 2023

J. Phys.: Conf. Ser.

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In the field of ultra-high-speed motors, windage loss rises rapidly with the increase of rotational speed, and even becomes the main part of motor loss. However, most researches of windage loss are based on empirical formulas, which has a narrow scope of application. These formulas could not guarantee the accuracy when calculating large Taylor number flow in high-speed motor air gap, especially under axial ventilation condition. This paper focuses on the interaction between Taylor vortices and axial flow, analyses the influence of Taylor number on the behaviour of Taylor vortices and windage loss under non-axial and axial ventilation. First, another form of friction coefficient related to rotation speed is proposed using dimension analysis. Second, the scale of Taylor vortices is estimated and how it affects windage loss is discussed. Finally, a deceleration experiment taking a 250krpm induction motor is used to verify the accuracy of the proposed windage loss model.

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Impact of Thermal Conductivity in Axial Direction on the Overall Thermal Model of High-Speed Synchronous Motor

Cited by 7 publications

References 18 publications

End-to-End Differentiable Physics Temperature Estimation for Permanent Magnet Synchronous Motor

End-to-End Differentiable Physics Temperature Estimation for Permanent Magnet Synchronous Motor

Thermal Effects in the End-Winding Region of Electrical Machines

Analysis of axial windage loss in air gap of high-speed motors under high Taylor number

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