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This paper aims to introduce a computationally efficient hybrid analytical–finite element (FE) methodology for loss evaluation in electric vehicle (EV) permanent magnet (PM) traction motor applications. In this class of problems, eddy current losses in PMs and iron laminations constitute an important part of overall drive losses, representing a key design target.

Both surface mounted permanent magnet (SMPM) and double-layer interior permanent magnet (IPM) motor topologies are considered. The PM eddy losses are calculated by using analytical solutions and Fourier harmonic decomposition. The boundary conditions are based on slot opening magnetic field strength tangential component in the air gap in the SMPM topology case, whereas the numerically evaluated normal flux density variation on the surface of the outer PM is implemented in the IPM case. Combined analytical–loss evaluation technique has been verified by comparing its results to a transient magnetodynamic two-dimensional FE model ones.

The proposed loss evaluation technique calculated the total power losses for various operating conditions with low computational cost, illustrating the relative advantages and drawbacks of each motor topology along a typical EV operating cycle. The accuracy of the method was comparable to transient FE loss evaluation models, particularly around nominal speed.

The originality of this paper is based on the development of a fast and accurate PM eddy loss model for both SMPM and IPM motor topologies for traction applications, combining effectively both analytical and FE techniques.

Several formulations have been developed solving 3D eddy current problems by the Finite element method based on vector quantities. Scalars, involving only one unknown per node of the mesh seem to be, however, more efficient. A particular scalar potential formulation has already been developed which is able to handle 3D magnetostatics,. This technique has been extended for cases involving eddy currents developed at low frequencies, where the skin effect can be neglected.

Some problems involve eddy currents developed in thin skin effect depths and a numerical analysis, based on the classical finite element method, is extremely laborious and expensive. Although such situations lead to operations concerning the linear part of the material characteristics, the related geometries are not, usually, simple enough to permit an analytical solution. The present work is based on a new type of element enabling efficient modeling in such cases. It combines the increased accuracy and speed of analytical solutions for large subdomains, a reduced number of unknowns and the advantages of functional minimization procedures.

The design of several electromagnetic devices, such as magnets and transformers, leads to a 3D magnetostatic field analysis. Although such problems can be solved by using vector potential formulations, scalar potential techniques seem to be more efficient because of the reduced number of unknowns they introduce. Even these methods, however, present certain drawbacks, depending on the way the scalar potential is defined: considerable cancellation errors in iron parts, difficulties to simulate multiply connected iron cores, a complicated way to compute a source field distribution.

To identify interactions existing between electromagnetic, electric and mechanical phenomena in variable speed permanent generator wind‐turbines and propose a methodology enabling oscillations analysis.

Evaluation of the accuracy of alternative approaches such as traditional fundamental and higher harmonic representation as well as coupled field, circuit and mechanical techniques based on the finite element method to represent such phenomena.

Low frequency oscillations observed experimentally necessitate strong coupling between electromagnetic, electrical and mechanical phenomena.

The techniques adopted are limited to two‐dimensional configurations, while possible three‐dimensional air‐gap eccentricity is not considered.

Special consideration should be paid by the wind turbine controller to attenuate the studied oscillations.

Development of an adequate modelling methodology enabling consideration of low frequency oscillations.

The paper presents a procedure for the design of claw pole alternators for small scale wind power applications. The method involves a preliminary design stage by means of the classical magnetic circuit analysis and a detailed design stage involving a 3D finite element model. This technique has been implemented in the design of a multiple generation for a small scale gearless autonomous system. The developed model can be implemented for the optimization of the rotor claw geometry through a minimization algorithm.

A large number of high-frequency harmonic voltages exist in the output voltage of the inverter, which will affect the performance of the motor. The purpose of this paper is to obtain the influence of high frequency harmonic voltage on the performance of the line start permanent magnet synchronous motor (LSPMSM) and reveal the mechanism of influence. The research results can provide help for the design of LSPMSM driven by inverter drives.

First, the actual output voltage data of the inverter is collected, and then the fundamental voltage and high frequency harmonic voltage data can be obtained by performing the fast Fourier transformation method on the voltage data. Second, the finite element model is established. During the finite element calculation, the obtained fundamental voltage and the main harmonic voltage components are used as the voltage source. To research the effect of high frequency harmonic voltage on the performance of motor, a reference group without high frequency harmonic voltage is set up, which is used to compare and analyze the effect of high-frequency harmonics on the performance of the motor. To verify the correctness of the model, a prototype based on the model parameters is manufactured, and then the back EMF experiment and load experiment are performed. The test data and calculation results are compared and analyzed.

The coupling relationship between high frequency time harmonic magnetic field and low frequency space harmonic magnetic field is obtained. The stator copper loss and rotor eddy-current loss are calculated and analyzed under normal supply voltage and abnormal supply voltage, and the influence mechanism is revealed

The coupling relationship between high frequency time harmonic magnetic field and low frequency space harmonic magnetic field is obtained. The sensitivity of the high frequency harmonic voltage to the stator copper loss and rotor eddy-current loss is obtained, and the mechanism of losses change is revealed.

Real-world applications in engineering and other fields usually involve simultaneous optimization of multiple objectives, which are generally non-commensurable and conflicting with each other. This paper aims to treat the transformer design optimization (TDO) as a multiobjective problem (MOP), to minimize the manufacturing cost and the total owing cost, taking into consideration design constraints.

To deal with this optimization problem, a new method is proposed that combines the unrestricted population-size evolutionary multiobjective optimization algorithm (UPS-EMOA) with differential evolution, also applying lognormal distribution for tuning the scale factor and the beta distribution to adjust the crossover rate (UPS-DELFBC). The proposed UPS-DELFBC is useful to maintain the adequate diversity in the population and avoid the premature convergence during the generational cycle. Numerical results using UPS-DELFBC applied to the transform design optimization of 160, 400 and 630 kVA are promising in terms of spacing and convergence criteria.

Numerical results using UPS-DELFBC applied to the transform design optimization of 160, 400 and 630 kVA are promising in terms of spacing and convergence criteria.

This paper develops a promising UPS-DELFBC approach to solve MOPs. The TDO problems for three different transformer specifications, with 160, 400 and 630 kVA, have been addressed in this paper. Optimization results show the potential and efficiency of the UPS-DELFBC to solve multiobjective TDO and to produce multiple Pareto solutions.

This paper aims to present an accurate representation of laminated wound cores with a low computational cost using 2D and 3D finite element (FE) method.

The authors developed an anisotropy model in order to model laminated wound cores. The anisotropy model was integrated to the 2D and 3D FE method. A comparison between 2D and 3D FE techniques was carried out. FE techniques were validated by experimental analysis.

In the case of no‐load operation of wound core transformers both 2D and 3D FE techniques yield the same results. Computed and experimental local flux density distribution and no‐load loss agree within 2 per cent to 6 per cent.

The originality of the paper consists in the development of an anisotropy model specifically formulated for laminated wound cores, and in the effective representation of electrical steels using a composite single‐valued function. By using the aforementioned techniques, the FE computational cost is minimised and the 3D FE analysis of wound cores is rendered practical.

An electromagnet that can produce strong pulsed magnetic fields at kHz frequencies is potentially very favourable to exert a Lorentz force on the metallic workpiece. One of the applications of the pulsed magnetic field is the electromagnetic forming where the design of robust electromagnet is critical. The purpose of this paper is to design a robust electromagnet (coil) for high velocity electromagnetic tube forming operation.

First of all, an analytical model is developed to design the electromagnet and predict the aluminium tube velocity under the action of the estimated pulsed magnetic field. Next, the finite element-based numerical model is used to test the robustness of the designed coil and validate the analytical model. The coil is fabricated and implemented for free forming of aluminium tube. Experimental results of tube displacement are further compared with numerical and analytical model results.

The experimental tube displacement results are showing a good match with analytical and numerical results. The designed electromagnet has generated a peak magnetic field around 14 T at 20 µs rise time and deformed the aluminium tube with a peak velocity of 160 m/s. Robustness of the electromagnet under the action of forming stress is insured by numerical stress analysis and experiments.

Though the designed model in this work is for the 2.4 mm aluminium tube forming, it can also be used for different tube materials, tube dimensions and other electromagnetic forming applications with some modifications.

The research results provide powerful theoretical, numerical simulation and experimental support for the robust electromagnet design.