Simplified Thermal Model of PM Motors in Hybrid Vehicle Applications Taking into Account Eddy Current Loss in Magnets

Ding, Xiaofeng; Bhattacharya, Madhur; Mi, Chris

doi:10.4130/jaev.8.1337

Cited by 30 publications

(12 citation statements)

References 21 publications

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“…Thermal analysis is of particular importance for PM motors because the magnets can be demagnetized at high temperatures [125]. Traction motors exhibit high frictional and windage losses due to high-speed operation, high magnetic losses due to high-frequency operation, and additional losses caused by PWM harmonics.…”

Section: Thermal Analysis and Modeling Of Traction Motors *mentioning

confidence: 99%

Electric Machines and Drives in HEVs

Masrur

Gao

2011

Hybrid Electric Vehicles

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Advances in electric machines, along with progress in power electronics, are the key enablers for electric, hybrid electric, and plug-in hybrid electric vehicles (HEVs). Induction machines, permanent magnet (PM) synchronous machines, PM brushless DC machines, and switched reluctance machines (SRMs) have all been considered in various types of vehicle powertrain applications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Brushed DC motors, once popular for traction applications such as in streetcars, are no longer considered a proper choice due to the bulky construction, low efficiency, the need for maintenance of the brush and commutator, high electromagnetic interference (EMI), low reliability, and limited speed range.When using electric motors for powertrain applications, there are a few possible configurations. Today's electric motors, combined with inverters and associated controllers, have a wide speed range for constant torque operations, and an extended speed range for constant power operations, which make the design of the powertrain much easier. Depending on the configuration of the hybrid powertrain, the design and selection of electric motor drives can also be different. For example, for series hybrid vehicles, the powertrain motor needs to be able to provide the required torque and speed for all driving conditions. Hence, the size of the motor will be fairly large, usually rated at 100 kW or more for passenger cars. A PM motor or an induction motor is the preferred choice. For mild and micro hybrids, only a small-size motor of a few kilowatts is required. Therefore the motor can be a claw pole DC motor, or a switched reluctance motor.Traditional automatic transmission or continuous variable transmission (CVT) used in conventional cars are no longer required in electric vehicles (EVs) and many HEVs. However, a fixed gear ratio speed reduction is often necessary. This is due to the fact that a high-speed motor has smaller size and less weight than a low-speed machine. A two-speed automatic transmission may be beneficial in saving vehicle energy consumption.Hybrid Electric Vehicles: Principles and Applications with Practical Perspectives, First Edition.

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Section: Thermal Analysis and Modeling Of Traction Motors *mentioning

confidence: 99%

Electric Machines and Drives in HEVs

Masrur

Gao

2011

Hybrid Electric Vehicles

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“…Along with the cooling technology development , the optimal thermal managements at the component and powertrain levels were simultaneously pursued [33][34][35][36][37][38][39][40]. The early attempts in this respect adopted the lumped-parameter thermal models that simplified the components into discrete units of thermal resistor, thermal capacitor and heat sources in the emulated thermal circuits [33][34][35].…”

Section: Introductionmentioning

confidence: 99%

“…A variety of iterative schemes were developed to cope with the temperature-dependent material properties which were influential to the electromagnetic-thermal analysis. The simplified model aimed at estimating the temperature rise in the components of the permanent magnetic motors considered the losses in the thermal circuit with the aid of finite element simulation to unravel the potential demagnetizing of the magnets due to the additional losses generated by power supplied with the Pulse Width Modulation (PWM) waveform [40]. To enhance the practical significance, the detailed temperature distributions in the components that constructed an electric motor for avoiding the demagnetizing of the magnets and the overheated spots need to be unraveled at the early design stage.…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer and Thermal Management of Interior Permanent Magnet Synchronous Electric Motor

Hsieh

Cai

et al. 2019

Inventions

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Geometric complexities and multi-physical phenomena add difficulties for predicting the thermal field and hence thermal management of an electric motor. A numerical design model that combined electromagnetic and thermal-fluid analysis was proposed for disclosing the detailed temperature distributions of each component in an electric motor. The thermal fluid analysis implemented ANSYS-Fluent code to unravel the thermal field of the interior permanent magnet synchronous electric motor fitted with a smooth or novel spirally twisted channel in the cooling water jacket of a stator with and without shaft cooling. In accordance with the thermal powers converted from the various electromagnetic losses of the electric motor, the complex heat conduction model with realistic thermal boundary conditions was formulated. Initially, the turbulent flow structures and channel averaged Nusselt numbers of the spiral channels without and with the sectional twist were comparatively examined for acquiring the convective thermal boundary conditions in the water jacket. With the high thermal conductivity of the aluminum water jacket, the heat-transfer improvements from the smooth-spiral-channel conditions by using the twisted spiral channel were effective for reducing the average temperatures by about 10% but less effective for altering the characteristic thermal field in the water jacket. At 1290 < Dn < 6455 or 5000 < Re < 25,000 for the spiral channel flows, the channel average Nusselt numbers ratios between the smooth and twisted spiral channels were elevated to 1.18–1.09 but decreased with the increase of Dn or Re. A set of heat-transfer correlations for estimating the Nusselt numbers of Taylor flow in the rotor-to-stator air gap was newly devised from the data available in the literature. While the cooling effectiveness of the water jacket and shaft was boosted by the sectional twists along the spiral channel of the water jacket, the presence of Taylor flow in the annual air gap prohibited the effective rotor-to-stator heat transmission, leading to hot spots in the rotor. By way of airflow cooling through the rotating hollow shaft, the high temperatures in the rotor were considerably moderated. As the development of Taylor flow between the rotor and stator was inevitable, the development of active or passive rotor cooling schemes was necessary for extending the power density of an electric motor. Unlike the previous thermal circuit or lumped-parameter thermal model that predicted the overall temperatures of motor components, the present coupled electromagnetic and thermal-fluid model can reveal the detailed temperature distributions in an electric motor to probe the local hot spots of each component in order to avoid overheating at the early design stage.

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“…For electrical machines, the iron losses computation is usually a very complex problem. Many authors [Zhu et al, 2002;Mi et al, 2003;Yamazaki et al, 2006;Seo et al, 2009;Tariq et al, 2009;Doffe et al, 2010;Chen et al, 2010;Barcaro et al, 2008;Ding et al, 2010] have proposed iron losses models to compute the iron losses in the electric machines that the authors [Krings and Soulard, 2010] has made an overview and comparison of iron losses models for electric machines. However, all proposed iron losses models are to compute the iron losses at a desired speed/torque or some speed/torque values.…”

Section: Introductionmentioning

confidence: 99%

“…We have not found in the literature an iron losses model applied for overall wide range of frequency yet. In [Yamazaki et al, 2006] [Seo et al, 2009Doffe et al, 2010;Barcaro et al, 2008;Ding et al, 2010;Akhondi et al, 2009], the authors proposed the losses calculation for the hybrid electric propulsion specially, but, it's only for an operating point or some operating points of the vehicle. Unfortunately, the vehicle operates not only at one point or at some driving points but at various torque/speed points.…”

Section: Introductionmentioning

confidence: 99%