A novel transverse flux machine for vehicle traction aplications (original) (raw)
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A Novel Transverse Flux Machine for Vehicle Traction Applications
novel transverse flux machine topology for electric vehicle traction applications using ferrite magnets is presented in this paper. The proposed transverse flux topology utilizes novel magnet arrangements in the rotor that are similar to the Halbach array to boost flux linkage; on the stator side, cores are alternately arranged around a pair of ring windings in each phase to make use of the entire rotor flux that eliminates end windings. Analytical design considerations and finite-element methods are used for an optimized design of a scooter in-wheel motor. Simulation results from finite element analysis (FEA) show that the motor achieved comparable torque density to conventional rare-earth permanent magnet (PM) machines. This machine is a viable candidate for direct-drive applications with low cost and high torque density.
Transverse flux machines with distributed windings for in-wheel applications
2009 International Conference on Power Electronics and Drive Systems (PEDS), 2009
Transverse flux machine (TFM) useful for in-wheel motor applications is presented. This transverse flux permanent magnet motor is designed to achieve high torque-to-weight ratio and is suitable for direct-drive wheel applications. As in conventional TFM, the phases are located under each other, which will increase the axial length of the machine. The idea of this design is to reduce the axial length of TFM, by placing the windings around the stator and by shifting those from each other by electrically 120 o or 90 o , for three-or two-phase machine, respectively. Therefore, a remarkable reduction on the total axial length of the machine will be achieved while keeping the torque density high. This TFM is compared to another similar TFM, in which the three phases have been divided into two halves and placed opposite each other to ensure the mechanical balance and stability of the stator. The corresponding mechanical phase shifts between the phases have accordingly been taken into account. The motors are modelled in finite-element method (FEM) program, Flux3D, and designed to meet the specifications of an optimisation scheme, subject to certain constraints, such as construction dimensions, electric and magnetic loading. Based on this comparison study, many recommendations have been suggested to achieve optimum results.
Comparison study of permanent magnet transverse flux motors (PMTFMs) for in-wheel applications
2009 International Conference on Power Electronics and Drive Systems (PEDS), 2009
This paper investigates the existing structures of transverse flux machines (TFMs) that can be constructed as an outer rotor in-wheel motor which is suitable for low speed applications. As the main characteristic of TFM is providing the best torque density at low speeds, it would be a suitable choice and having a great future for low speed mobile platforms. Different structures of TFM are redesigned as outer rotor motors with the same diameter, axial length and pole number and they undergo a comparison study through the use of three dimensional (3D) finite element method (FEM). The simulations have been done via Flux3D software from Cedrat. An analytical study of the TFMs is done in terms of highest torque production capability and design optimisation.
High Performance Low Cost Electric Motor for Electric Vehicles Using Ferrite Magnets
IEEE Transactions on Industrial Electronics, 2015
Permanent magnet motors with rare earth magnets are amongst the best candidates for high performance applications such as automotive. However, due to their cost and risks relating to security of supply, alternative solutions such as ferrite magnets have recently become popular. In this paper the two major design challenges of using ferrite magnets for a high torque density and high speed application, namely their low remanent flux density and low coercivity, are addressed. It is shown that a spoke type design utilizing a distributed winding may overcome the torque density challenge due to a simultaneous flux concentration and reluctance torque possibility. Furthermore, the demagnetization challenge can be overcome through careful optimization of the rotor structure, with the inclusion of non-magnetic voids on the top and bottom of the magnets. To meet the challenges of the high speed operation an extensive rotor structural analysis has been undertaken, during which electro-magnetics as well as manufacturing tolerances are taken into account. The electromagnetic studies are validated through testing of a prototype, custom built for static torque and demagnetization evaluation. The disclosed motor design surpasses the state of the art performance and cost, merging the theories into a multidisciplinary product.
A Review of Transverse Flux Machines Topologies and Design
Energies
High torque and power density are unique merits of transverse flux machines (TFMs). TFMs are particularly suitable for use in direct-drive systems, that is, those power systems with no gearbox between the electric machine and the prime mover or load. Variable speed wind turbines and in-wheel traction seem to be great-potential applications for TFMs. Nevertheless, the cogging torque, efficiency, power factor and manufacturing of TFMs should still be improved. In this paper, a comprehensive review of TFMs topologies and design is made, dealing with TFM applications, topologies, operation, design and modeling.
On Selection of Rotor Support Material for a Ferrite Magnet Spoke Type Traction Motor
IEEE Transactions on Industry Applications, 2016
Interior permanent magnet motors with ferrite magnets and distributed windings can be a cost effective alternative to rare-earth magnet based motors for demanding applications such as automotive traction. Among different rotor topologies, the spoke type may be preferred, due to its advantages for high flux concentration and resistance to demagnetization, when carefully designed. When high speed operation is required, to increase the power density of the motor, the spoke type rotor must comprise of two sections: a) the ferromagnetic rotor pole to provide the path for the magnetic flux, and b) the non-magnetic rotor support to provide the structural integrity. In this paper, the multiphysics and cost implications of the rotor support material, as part of a high performance ferrite magnet traction motor, are analyzed, and an optimal selection with respect to those criteria is proposed. The performance of the design based on the proposed rotor support material is validated by electromagnetic and structural testing of three sets of customized prototypes. Based on the analysis, the proposed rotor support material may, significantly, boost the cost competitiveness of a low cost ferrite motor for high volume production.
IEEE Transactions on Industry Applications, 2012
This paper proposes a novel permanent magnet flux switching (PMFS) machine with an outer-rotor configuration for in-wheel light traction applications. The geometric topology of the outer-rotor PMFS machine is introduced and the analytical sizing equations are derived to determine the main design parameters of the machine. Two-dimensional (2-D) Finite element analysis (FEA) models are developed to investigate and optimize the machine performance. Furthermore, the flux weakening capability of the machine is analyzed and further improved by segmental permanent magnets with iron bridges. The machine performance predictions by 2-D FEA models are validated by experimental tests on the prototype machine. The suitability of the proposed outer-rotor PMFS machine for in-wheel light traction application is demonstrated. Index Terms-Back electromotive force, cogging torque, finite element analysis, flux switching, flux weakening, light traction, outer rotor, permanent magnet machine. rban pollution and traffic congestion have been two of the most pressing issues in our cities. They have direct adverse impacts on the health of the citizens and the productivity of the cities. Electric propelled light traction vehicles, with zero tailpipe emission and great agility in traffic, provide ideal solutions to alleviate these problems. Thus, the demands for electric scooters, rickshaws and bicycles have grown very rapidly, in particular in countries such as India and China [1,. Currently, there is a trend to use in-wheel motors for such electric vehicles due to their compactness. An outer-rotor configuration provides higher torque density than an axial-flux or inner-rotor one in a low-speed in-wheel drive, and is therefore particularly suitable for in-wheel light traction applications. For the motor itself, the permanent magnet (PM) type offers high efficiency and compactness which are additional benefits for electric vehicles.
Comparison Study of Electric Machines for In-Wheel Electric Vehicle Application
2016
Electric vehicle motoring is became a famous task due to several problems caused by thermal engine such as pollution and high oil prices. Thus, electric motor is seen as the solver of these problems. So, different research was done about these motors and its applications. Different configurations were proposed in the literature. Each configuration has its own intrinsic features depending on the industrial application. The variety of industrial applications can lead to different choices. Therefore, the choice of a permanent magnet topology must be carefully made. In this paper, a comparison between different machines according to some criteria was done to choose the most suitable for in-wheel motor application. Keywords— Electric machine, in-wheel motor, efficiency, comparison.
Cost reduction of a permanent magnet in-wheel electric vehicle traction motor
2014 International Conference on Electrical Machines (ICEM), 2014
This paper describes a motor fo wheel of an electric vehicle. It demonstrates various rotor parameters on an outer rotor pe motor (ORPM) with Surface-mounted magnets this paper is to reduce the magnet volume, whil torque performance through the complete ope different magnet topologies are investigated fir Surface-mounted Permanent Magnet (SSPM), I PM (IPM) and V shape interior PM (VPM) desig in terms of torque capability at certain magnet v gives highest torque performance. The iron shi VPM can protect the magnets from the opposin thus providing increased resistance to dema hence permitting thinner magnets. Furthermor combination with higher torque capability h However, due to the increased inductance, mo design needs to work at a poorer power factor a reduced speed range for a given inverter. Las and simple manufacture method of the VP addressed with consideration of mechanical feas Keywords-Cost Reduction, In-wheel Motor shape magnets I.