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This paper presents a multi-physic analytical model for a permanent magnet assisted synchronous reluctance motor. The proposed model consists of: an electromagnetic model, an electrical model, a loss model, and a thermal model. The electromagnetic model is based on Maxwell's equations. Stator and rotor magnetic saturation is considered, as well as the effect of the magnetic bridges of the flux-barriers. The electrical model computes the terminal voltage and power factor. Copper loss and iron losses are also considered. The thermal model makes an estimation of the winding and magnet temperature. The goal is to compute the motor performances (average torque, voltage, power factor, efficiency etc.) for several current values and current angles. The analytical model results are compared with those from a finite element model and are subsequently validated by an experimental prototype. [ABSTRACT FROM AUTHOR]

An innovative approach, named topology exploration, is introduced in this paper. The aim of this approach is to help in the creation of electromagnetic devices, and to explore a priori unknown structures. In so doing, a general analytical solution of the magnetic field in static-excited cylindrical machines is developed, and then coupled to a stochastic procedure to determine if some structures are viable. The analytical model can account for variable boundary conditions, and hence, is suitable to determine electromagnetic performances of any structures. After 3 months of calculations, the topology exploration approach revealed interesting results showing the validity of the method. [ABSTRACT FROM AUTHOR]

A general solution of the magnetic field in the airgap of conventional and alternate field-excited switched-flux (FE-SF) machines is proposed in this paper. The analytical model is based on the subdomain method. It involves the solution of governing field equations in a doubly slotted airgap using the variable separation method. The complete model is derived and described in a general manner so that it can be easily extended to unconventional FE-SF topologies. By means of example, analytical predictions of airgap field are extensively compared and validated using 2D FE results. FE simulations were performed on a 24-10 classical FE-SF structure and also on a novel 18-11 FE-SF machine with additional spacer teeth. [ABSTRACT FROM PUBLISHER]

Field-Excited Flux-Switching machines are doubly-salient machines with complex flux-density waveforms in the core. Hence, prediction of iron losses is difficult. In this article, we propose a method to determine flux loci in iron parts in an analytical manner, accounting for bidirectional field in back-irons of stator and rotor. The analytical model for flux-density prediction in the core at no-load was first validated with 2D FE simulations. Then measured iron losses on a prototype machine were used to calibrate an iron loss model. It was shown that in FE-SF machines rotor iron losses are not negligible and represent 28% of total iron losses. This model could be advantageously used in a design optimization procedure. [ABSTRACT FROM AUTHOR]

In this paper, an analytical approach for the prediction of the armature reaction field of field-excited flux-switching (FE-FS) machines is presented. The analytical method is based on the magnetomotive force (MMF)-permeance theory. The doubly-salient air-gap permeance, developed here, is derived from an exact solution of the slot permeance. Indeed, the relative slot permeance is obtained by solving Maxwell's equations in a subdomain model and applying boundary and continuity conditions. In addition, during a no-load study, we found that, regarding the stator-rotor teeth combination, phase distributions were modified. Hence, in this paper, phase MMF distributions, for q phases, several stator-rotor combinations and also phase winding distribution (single- or double-layers) are proposed. We compare extensively magnetic field distributions calculated by the analytical model with those obtained from finite-element analyses. Futhermore, the model is used to predict the machine inductances. Once again, FE results validate the analytical prediction, showing that the developed model can be advantageously used as a design tool of FE-FS machine. [ABSTRACT FROM AUTHOR]

This paper presents a general and accurate approach to determine the no-load flux of field-excited flux-switching (FE-FS) machines. These structures are inherently difficult to model due to their doubly-slotted air gap. This analytical approach is based on magnetomotive force-permeance theory. The analytical model developed is extensively compared to field distribution obtained with 2-D finite element (2-D FE) simulations. The good agreement observed between analytical model and 2-D FE results emphasizes the interest of this general approach regarding the computation time. Hence, this analytical approach is suitable for optimization process in pre-sizing loop. Furthermore, based on the field model, classical electromagnetic performances can be derived, such as flux linkage and back-electromotive force (back-EMF) and also, unbalanced magnetic force. Once again, FE results validate the analytical prediction, allowing investigations on several stator-rotor combinations, or optimization of the back-EMF. [ABSTRACT FROM PUBLISHER]

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]