A Comprehensive Analytical Sizing Methodology for Transverse and Radial Flux Machines (original) (raw)

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.

A novel transverse flux machine for vehicle traction aplications

2015 IEEE Power & Energy Society General Meeting, 2015

A 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.

Analytical Optimal Design of a Two-Phase Axial-Gap Transverse Flux Motor

Energies

Transverse flux motors (TFMs) are being investigated to be used in vehicle traction applications due to their high torque density. In this paper, a two-phase axial-gap transverse flux motor is designed for an electric scooter, proposing a novel analytical design method. First, the dimensioning equations of the motor are obtained based on the vehicle requirements, and the stationary dq model is calculated. Then, the motor is optimized using a multiobjective genetic algorithm, and finally a 3D-FEM verification is made. Both the motor structure and the design method aim to have a low complexity, in order to favor the sizing and manufacturing processes through a low computation time and simple core shapes. This approach has not yet been explored in axial-gap TFMs.

Analytical 3-D Design of a Transverse Flux Machine with High Power Factor

Low-speed high-torque applications, e.g. wind energy generation, favor high number of pole solu­ tions. for traditional radial or axial flux machines this leads to an increase in leakage flux while the power output does not increase. For Transverse Flux Machines (TFM) the increase in power output is proportional to the number of poles. However, large flux leakage is also present in TFMs, reducing their power factor and commercial application. Fast and accurate 3-D models are required to model this flux leakage. Finite Element Models (FEM) comprising a large number of elements are commonly used to calculate the 3-D flux density distribution. This approach is very time consuming with hours for a single solution. A fast and more accurate parameterized model is essential to minimize the machine volume while maintaining the required power factor. In this paper, a design approach is presented to obtain a TFM of a minimum volume with a predefined power factor. An analytical 3-D magnetic charge model is used to model a single magnetic period of the TFM. With the required power factor and the obtained flux due to the magnets the coil dimensions are calculated. The performance of the single magnetic period of the TFM is used to determine the full machine dimensions.

Optimization of the transverse-flux motor based on design of experiments

2009 International Conference on Power Electronics and Drive Systems (PEDS), 2009

The objective of the paper is optimization of the outer rotor permanent-magnet transverse-flux motor using design of experiments. First, the 3-D time-stepping finite-element analysis is used to evaluate the relationship between the measured and calculated results. Further, in the 3-D time-stepping finiteelement analysis a parametric model of the transverse-flux motor is coupled with an external three-phase current source to analyze the impact of the motor geometric parameters on its performance. The objectives of the motor geometry optimization are maximization of the nominal electromagnetic torque, minimization of torque pulsations, reduction of local magnetic saturation of ferromagnetic parts and increase in the current overloading regarding magnetic saturation. All the optimization objectives should be realized in a single transverse-flux motor design.

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.

An Insight into Torque Production and Power Factor in Transverse-Flux Machines

IEEE Transactions on Industry Applications, 2017

Despite transverse flux machines (TFMs) being intrinsically three-dimensional, it is still possible to model them analytically using relatively simple models. This paper aims to provide an insight into the behaviour of TFMs using a compact equation, which relates torque to the electric and magnetic loadings of the machine and a flux factor. The flux factor is also used to estimate the flux linkage and therefore the power factor of this kind of machines. It is shown that the low power factor of TFMs is not only due to leakage but also due to the nature of the electromagnetic interaction that takes place. The TFM developed at the University of Southampton is used as the basis of a case study to illustrate the trade-off between torque density and power factor, and to provide some design guidelines. The analytical results are verified using finite elements analysis and experimental data. Index Terms-Analytical models, permanent magnet machines, power factor, torque, transverse-flux machines.

Design Considerations of Permanent Magnet Transverse Flux Machines

IEEE Transactions on Magnetics, 2000

-drive applications. Due to its complicated 3-D flux components, design and design optimization of a PMTFM is more difficult and time consuming than for radial flux electrical machines. This paper addresses two important design considerations for PMTFM-the influence of permanent magnet leakage flux, which plays an important role in the determination of machine output torque, and the leakage inductance. A new simple method to provide a quick estimation of the armature leakage inductance is proposed, avoiding use of complicated 3-D equivalent reluctance network model to estimate the circumferential armature leakage flux component, and the pole face fringing flux component. Analysis results are supported by 2-D, and 3-D finite element (FE) analysis results, and measurement results on a prototype surface-mounted PMTFM. Index Terms-Inductance, leakage flux, permanent magnet, transverse flux machine.

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.