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This paper presents a nonlinear analytical model of a multi-V-shape interior permanent magnet (IPM) motor with nonoverlapping concentrated winding. The model relies on Ampere's theorem and the flux conservation law in order to compute the flux density in the different parts of the motor. This article proposes a saturated analytical model of the stator and the rotor. The analytical model is used to calculate the average torque, the power factor, and the voltage of the motor. It is five times faster than the 2-D finite element analysis (FEA). The results are compared with 2-D FEA simulations and experimentally validated using a prototype motor. [ABSTRACT FROM PUBLISHER]

A finite-element formulation based on the use of magnetic scalar potential is proposed. It allows to describe circuit-coupled electromagnetic formulation using magnetic scalar potential in presence of multiply connected solid conductors (with holes), treated by surface impedance condition. This formulation offers powerful solutions at a low cost. An example of application is given. [ABSTRACT FROM AUTHOR]

Based on the Stieltjes integral, this paper investigates the characteristics of the torque area of surface permanent magnet motors with sinusoidal magnetization used in hard disk drives. Then, a simple torque calculation algorithm is proposed and verified through comparison with the finite element analysis. Meanwhile, an improved motor having the sintered NdFeB with sinusoidal magnetization and smaller airgap length is recommended. [ABSTRACT FROM PUBLISHER]

By visualizing the torque as an area enclosed by locus of magnet operating points in B\-H plane, several surface mounted permanent magnet (SPM) motors with different pole/slot combinations for hard disk drive (HDD) spindle motors are analyzed to clarify their geometrical characteristics of the maximum torque area. Then, a simple and fast calculation algorithm of predicting the maximum torque is proposed based on the torque geometrical interpretation and its validity is verified through comparison with FEA results. In addition, optimum pole/slot combinations for modern HDD spindle motors are recommended from the view points of reducing vibration resource caused by cogging torque and increasing speed control accuracy. [ABSTRACT FROM AUTHOR]

High-speed electric drive design is concerned with paying particular attention to thermal and mechanical design of the machine. Therefore, this paper proposes a multiphysic modeling of an interior permanent-magnet synchronous machine (IPMSM) dedicated to high speed, including magnetic, electric, thermal, and mechanical aspects. The proposed analytical models are verified using finite-element (FE) computations. These models are then subjected to a multiobjective optimization—based on genetic algorithm—to design an IPMSM for a high-speed compressor application that develops 30 kW at 20 000 r/min. The design is formulated as a constrained optimization problem consisting of maximizing the machine efficiency while minimizing its weight. The result of this process is a Pareto front between efficiency and weight of the machine allowing the designer to make a posteriori choice. A particular optimal machine is chosen and its performances are validated with FE analysis. This study carries out an optimal multiphysic and multiobjective design approach that allows rationalization of the design process in a realistic computation time thanks to the analytical models involved. [ABSTRACT FROM AUTHOR]

A robust numerical method based on 2-D mixed finite-elements-finite volumes (FE-FV) allows the solution of diffusion problems in superconducting (SC) materials. The proposed approach handles the strong nonlinearity of the E(J) constitutive power law of high-temperature superconductors (HTS). The method is tested for a SC cylinder submitted to a sinusoidal transport current or to a transverse sinusoidal external field. The current density distributions as well as the AC losses are computed. Comparisons to a FE analyses that use the magnetic field as state variable show the validity of the proposed approach. It can be seen that the proposed method is very stable even for large n-values for which the FE method does not converge. [ABSTRACT FROM AUTHOR]

The complementary energy bounds of dual formulations on dual meshes for eddy current problems are investigated. Based on the algebraic discretization of Maxwell equations on the dual meshes using different working variables, two sets of dual formulations, both for the finite-element method (FEM) and the finite integral technique (FIT), can be derived. A rational comparison between these formulations and the circuit networks is performed. The complementary bounds of magnetic energy and power losses are studied through an example. The study shows that the energy bounds are due to the numerical discretization of the Hodge operators on dual meshes. The dependency of the upper and lower energy bounds on the field excitation is also illustrated. The relation of the numerical bounds of the global circuit elements to the dual mesh discretization is given. [ABSTRACT FROM AUTHOR]

This paper analyzes the efficiencies of the new coupling between finite-element methods (FEMs) and the partial element equivalent circuit method (PEEC), which are computation time and memory space. To show its performance, a common mode filter is modeled by the coupling and the results are then compared with those of a FEM analysis. The comparison shows that the coupling is very efficient to model electromagnetic systems comprising magnetic materials and systems of complex thin conductors. [ABSTRACT FROM AUTHOR]

The contribution of powerful numerical calculation methods in the design procedure of electrical actuators is usually restricted to the analysis of structures with known geometric dimensions. This paper describes a computer-aided design tool with a multiphysics design methodology starting from datasheet specifications. It is operational from the first design phases due to the association of analytical and numerical approaches that are performed by the coupling of two software tools. The analytical study associates a coupled electromagnetic-thermal model with a gradient optimization algorithm and provides a quick first solution. This solution is then optimized, according to other criteria, by a further numerical study that is based on a finite-element model that is linked to a simplex algorithm. The vibratory behavior of the obtained solution is finally studied using modal analysis. This methodology is applied to design a permanent-magnet synchronous machine. [ABSTRACT FROM AUTHOR]

When the total current going through a transformer window is equal to zero, only a negligible part of the magnetic energy reaches its core. This is shown by finite-element-method simulations carried out on several two-winding transformers having different shapes. Moreover, induction and energy-density values obtained by 3-D simulations and by 2-D approximations are very close to each other. These two key observations justify the use of formulas that give the induction created by straight rectangular cross-sectional wires, as used in the partial-element-equivalent-circuit method, to compute the window field and, thus, to value the leakage inductances. To refine this approach, weak magnetic-core effects are accounted for by introducing the magnetic images of currents that flow in the windings. A comparison between the calculated values and measured ones is provided. [ABSTRACT FROM AUTHOR]

Presents the theory and the validation of a finite-element formulation to realize the coupling between electric circuits and multiply connected magnetic circuits, using a magnetic scalar potential as state variable. Computation with a multiply connected domain; Description of the current transformer.

Presents information on a study which proposed a finite element method for modeling the imposed currents in several long conductors. Characteristic of superconducting materials; Formulation and numerical solution; Results and discussions; Conclusions.