The Experts below are selected from a list of 4458 Experts worldwide ranked by ideXlab platform
Mohammed Kimiabeigi - One of the best experts on this subject based on the ideXlab platform.
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electric vehicle Traction Motors without rare earth magnets
Sustainable Materials and Technologies, 2015Co-Authors: James D Widmer, Richard A Martin, Mohammed KimiabeigiAbstract:Abstract Since the Hybrid Electric Vehicle (HEV) became main-stream with the launch of the Toyota Prius in 1997, the use of rare earth magnets in vehicle Traction Motors has become common. In particular the rare earth based, hard magnetic material Neodymium Iron Boron (NdFeB) has offered significant performance benefits, not possible with other technologies, enabling the development of compact, torque- and power-dense electric Traction Motors. This trend has continued as mass market Battery Electric Vehicles (BEV) such as the Nissan Leaf, have come to market. However in 2011–2012 the price of these materials rose significantly, owing to geopolitical concerns relating to security of supply. Whilst the price has recovered more recently closer to historical levels, concern still remains in the minds of governments and many manufacturers of hybrid and electric vehicles. Reports have also raised questions over the environmental sustainability of these materials and this has further encouraged users to consider alternatives. This paper therefore examines why these magnetic materials have been so successful in Traction motor applications. It also explores the alternatives, including those which are ready for market and those which are in the process of being developed.
James D Widmer - One of the best experts on this subject based on the ideXlab platform.
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cooling of automotive Traction Motors schemes examples and computation methods
IEEE Transactions on Industrial Electronics, 2019Co-Authors: Yaohui Gai, James D Widmer, Mohammad Kimiabeigi, Yew Chuan Chong, Xu Deng, Mircea Popescu, James Goss, Dave Staton, A StevenAbstract:This paper presents a comprehensive over-view of the latest studies and analyses of the cooling technologies and computation methods for the automotive Traction Motors. Various cooling methods, including the natural, forced air, forced liquid, and phase change types, are discussed with the pros and cons of each method being compared. The key factors for optimizing the heat transfer efficiency of each cooling system are highlighted here. Furthermore, the real-life examples of these methods, applied in the latest automotive Traction motor prototypes and products, have been set out and evaluated. Finally, the analytical and numerical techniques describing the nature and performance of different cooling schemes have been explained and addressed. This paper provides guidelines for selecting the appropriate cooling methods and estimating the performance of them in the early stages of their design.
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shaft cooling and the influence on the electromagnetic performance of Traction Motors
International Electric Machines and Drives Conference, 2017Co-Authors: Yaohui Gai, James D Widmer, Mohammad Kimiabeigi, Yew Chuan Chong, James Goss, Unai Sanandres, D StatonAbstract:This paper addresses the heat transfer coefficient associated with a shaft-cooling of Traction Motors. In such shaft-cooling systems, the 50–50 ethylene glycol-water is made to flow through the shaft hole in order to cool the machine. The heat transfer coefficient is estimated using a computational fluid dynamics(CFD) method, where the effect of the rotational velocity as well as the liquid flow rate have been accounted for. The results from two different turbulence models were compared. As a result of the simulations, it is concluded that the rotational speed can significantly increase the convective heat transfer in the shaft hole above the stationary condition. Finally, the benefits of implementing a shaft-cooling to an existing ferrite magnet Traction motor, in terms of the continuous torque capability, is described.
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pre compressed and stranded aluminium motor windings for Traction Motors
International Electric Machines and Drives Conference, 2015Co-Authors: James D Widmer, Richard Martin, B C MecrowAbstract:There are benefits if copper windings are replaced with aluminum in applications that are cost- and mass-sensitive, such as automotive Traction; these include the low cost of aluminum, low mass of aluminum, and the ease of motor recycling at the end of life. However, the relatively low electrical conductivity of aluminum compared to copper needs to be overcome. Precompressed motor coils have been shown to produce very high fill factors ( $ > 75\%$ ), reducing dc-winding losses, therefore enabling the use of aluminum conductors. However, the single-stranded conductors used can be prone to high ac losses due to skin and proximity effects. Therefore, a method of manufacture of precompressed coils made from stranded/Litz wire is needed, allowing ac losses to be reduced to low levels. This paper describes the development and test of stranded, precompressed aluminum coils, which have been developed for use in an automotive Traction application.
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electric vehicle Traction Motors without rare earth magnets
Sustainable Materials and Technologies, 2015Co-Authors: James D Widmer, Richard A Martin, Mohammed KimiabeigiAbstract:Abstract Since the Hybrid Electric Vehicle (HEV) became main-stream with the launch of the Toyota Prius in 1997, the use of rare earth magnets in vehicle Traction Motors has become common. In particular the rare earth based, hard magnetic material Neodymium Iron Boron (NdFeB) has offered significant performance benefits, not possible with other technologies, enabling the development of compact, torque- and power-dense electric Traction Motors. This trend has continued as mass market Battery Electric Vehicles (BEV) such as the Nissan Leaf, have come to market. However in 2011–2012 the price of these materials rose significantly, owing to geopolitical concerns relating to security of supply. Whilst the price has recovered more recently closer to historical levels, concern still remains in the minds of governments and many manufacturers of hybrid and electric vehicles. Reports have also raised questions over the environmental sustainability of these materials and this has further encouraged users to consider alternatives. This paper therefore examines why these magnetic materials have been so successful in Traction motor applications. It also explores the alternatives, including those which are ready for market and those which are in the process of being developed.
Kumkang Huh - One of the best experts on this subject based on the ideXlab platform.
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comparison of Traction Motors that reduce or eliminate rare earth materials
IET electrical systems in transportation, 2017Co-Authors: Ayman Mohamed Fawzi Elrefaie, Tsarafidy Raminosoa, Patel Bhageerath Reddy, Steven Galioto, Di Pan, Kevin Grace, James Pellegrino Alexander, Kumkang HuhAbstract:Important global efforts are underway toward lowering the cost of electric machines for electric and hybrid vehicles by reducing or eliminating the use of rare earth materials which have been experiencing significant price increases and volatility. This study will present several designs that reduce or eliminate rare-earth materials. All these designs are targeting the same set of specifications of 55 kW peak at 2800 rpm and 30 kW continuous over a speed range going from 2800-14,000 rpm. This provides a fair basis of comparison of various machine topologies. The study will provide a quantitative comparison of the performance of various machine topologies as well as highlight the key tradeoffs.
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comparison of Traction Motors that reduce or eliminate rare earth materials
European Conference on Cognitive Ergonomics, 2016Co-Authors: Ayman Mohamed Fawzi Elrefaie, Tsarafidy Raminosoa, Patel Bhageerath Reddy, Steven Galioto, Di Pan, Kevin Grace, James Pellegrino Alexander, Kumkang HuhAbstract:Important global efforts are underway toward lowering the cost of electric machines for electric and hybrid vehicles by reducing or eliminating the use of rare earth materials which have been experiencing significant price increases and volatility. This paper will present several designs that reduce or eliminate rare-earth materials. All these designs are targeting the same set of specifications of 55kW peak at 2800 rpm and 30kW continuous over a speed range going from 2800 rpm to 14000 rpm. This provides a fair basis of comparison of various machine topologies. The paper will provide a quantitative comparison of the performance of various machine topologies as well as highlight the key tradeoffs.
Atsuhito Honda - One of the best experts on this subject based on the ideXlab platform.
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recent development of non oriented electrical steel sheet for automobile electrical devices
Journal of Magnetism and Magnetic Materials, 2008Co-Authors: Yoshihiko Oda, Masaaki Kohno, Atsuhito HondaAbstract:This paper describes non-oriented electrical steel sheet for automobile Motors and reactors. Electrical steel sheets for energy efficient Motors show high magnetic flux density and low iron loss. They are suitable for HEV Traction Motors and EPS Motors. A thin-gauge electrical steel sheet and a gradient Si steel sheet show low iron loss in the high-frequency range. Therefore, the efficiency of high-frequency devices can be greatly improved. Since a 6.5% Si steel sheet possesses low iron loss and zero magnetostriction, it contributes to reduce the core loss and audible noise of high-frequency reactors.
Tsarafidy Raminosoa - One of the best experts on this subject based on the ideXlab platform.
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impact of ultra conducting winding on the power density and performance of non heavy rare earth Traction Motors
International Electric Machines and Drives Conference, 2019Co-Authors: Tsarafidy Raminosoa, T AytugAbstract:The emergence of carbon nanotube-copper composite conductors has opened a new degree of freedom in the electric machine design to improve the machine's performance: the conductivity of the winding. The goal of the present study is: 1) to determine how much improvement in power per unit volume and performance can be achieved with the increase in winding conductivity; and 2) to investigate any physical limitations on the effectiveness of this degree of freedom in improving the power per unit volume and performance of electric Traction Motors. Conventional electric motor topologies affected by ferromagnetic saturation as well as slotless topology that is not affected by saturation are analyzed. It was found that the ferromagnetic saturation of the lamination materials reduces the effectiveness of highly conductive winding in improving the power per unit volume. For machine topologies that are not affected by ferromagnetic saturation, the power density improvement reaches the theoretical expectation. In both cases, highly conductive winding improves the efficiency map by enlarging high efficiency operating area into light load as well as high speed operations.
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Contactless Rotor Excitation for Traction Motors
2018 IEEE Energy Conversion Congress and Exposition (ECCE), 2018Co-Authors: Tsarafidy Raminosoa, Randy WilesAbstract:This paper proposes a new rotary transformer topology enabling significant reduction of leakage inductances, improvement of coupling factor and significant improvement of power transfer capability compared to traditional topologies thanks to its interleaved windings and resonant compensation circuits. The proposed rotary transformer features a non-ferrite rotating part made of lightweight strong non-conductive and non-magnetic composite material and a large airgap, allowing safe operation at high rotational speeds. Hence, this novel rotary transformer can enable the adoption of wound rotor synchronous machines for electric or hybrid vehicle Traction. The performance of the proposed new topology was evaluated and compared to the conventional one. Significant performance improvement was confirmed.
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comparison of Traction Motors that reduce or eliminate rare earth materials
IET electrical systems in transportation, 2017Co-Authors: Ayman Mohamed Fawzi Elrefaie, Tsarafidy Raminosoa, Patel Bhageerath Reddy, Steven Galioto, Di Pan, Kevin Grace, James Pellegrino Alexander, Kumkang HuhAbstract:Important global efforts are underway toward lowering the cost of electric machines for electric and hybrid vehicles by reducing or eliminating the use of rare earth materials which have been experiencing significant price increases and volatility. This study will present several designs that reduce or eliminate rare-earth materials. All these designs are targeting the same set of specifications of 55 kW peak at 2800 rpm and 30 kW continuous over a speed range going from 2800-14,000 rpm. This provides a fair basis of comparison of various machine topologies. The study will provide a quantitative comparison of the performance of various machine topologies as well as highlight the key tradeoffs.
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comparison of Traction Motors that reduce or eliminate rare earth materials
European Conference on Cognitive Ergonomics, 2016Co-Authors: Ayman Mohamed Fawzi Elrefaie, Tsarafidy Raminosoa, Patel Bhageerath Reddy, Steven Galioto, Di Pan, Kevin Grace, James Pellegrino Alexander, Kumkang HuhAbstract:Important global efforts are underway toward lowering the cost of electric machines for electric and hybrid vehicles by reducing or eliminating the use of rare earth materials which have been experiencing significant price increases and volatility. This paper will present several designs that reduce or eliminate rare-earth materials. All these designs are targeting the same set of specifications of 55kW peak at 2800 rpm and 30kW continuous over a speed range going from 2800 rpm to 14000 rpm. This provides a fair basis of comparison of various machine topologies. The paper will provide a quantitative comparison of the performance of various machine topologies as well as highlight the key tradeoffs.