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This aim of this paper is to assess the efficacy of mesh-based generated reluctance network (MGRN) modeling for the performance evaluation of a permanent magnet linear machine under load conditions. In the previous publications related to the use of this modeling technique, only approach implementation under an open-circuit performance has been assessed. The MGRN approach is based on the discretization of the geometry using elementary reluctance blocks (reluctance elements). This modeling technique has been implemented in a software tool that allows the automated processing of an arbitrary geometry providing a gain in model development durations. Validation of the MGRN model has been realized by comparison with a finite element analysis (FEA). Comparisons showed that both local and global quantities evaluated by MGRN and FEA are in excellent agreement. [ABSTRACT FROM AUTHOR]

The aim of this study is to analyze the vibration behavior of a five-phase flux switching machine in order to detect and discriminate full and partial open-phase faults. To achieve our goal, radial magnetic stress was calculated by two magnetic models. The first magnetic model, presented in this paper, is obtained by finite element analysis (FE) and the second one by permeance network analysis (PN) of the studied electrical machine. Stator radial accelerations were evaluated coupling each of the two magnetic models with an analytical mechanical model. The results of two multiphysics models are compared with experimental results, in order to validate them. Experimental measurements are performed under healthy and faulty conditions, at fixed rotational speed. For faulty conditions, full open-phase and partial open-phase fault of the stator winding were analyzed. [ABSTRACT FROM AUTHOR]

This paper presents performance improvements of a double excitation synchronous motor by using a reluctance network (RN). The distinguishing feature of the double excitation principle is to use permanent magnets with high energy, while air-gap flux is flexibly controlled by field windings. Therefore, the first contribution of this paper focuses on maximizing air-gap flux range control. Second, an approach for torque ripple reduction is proposed by directly modifying air-gap flux according to the instantaneous torque profile. The achieved resultant torque stays almost constant for a case study. The validity of the RN method is examined by comparisons with 3-D finite element and experimental results for several machines. [ABSTRACT FROM AUTHOR]

This paper describes an analytical model for computing the rotor eddy-current losses in the case of permanent magnet synchronous machines, based on a formal resolution of Maxwell’s equations. We focus on the computation of the eddy currents in the machine magnets, in which the diffusion equation is analytically solved, using an accurate electromagnetic model of the stator slotting. The model originality lies in its capacity of taking into account both the diffusion phenomenon and the magnet’s finite length over the pole pitch, imposing that the total current over the magnet’s surface should be zero at each instant. This important problem is studied by solving a Fredholm integral equation. A validation using a 2-D time-stepping finite-element model is also performed, and the obtained losses are shown to be in good agreement with those given by the analytical method, for a shorter computation time. [ABSTRACT FROM AUTHOR]

This paper presents two short-circuit fault models of a hybrid excitation flux switching permanent magnet machine, i.e., excitation phase short-circuit and interturn short-circuit in excitation windings. Two-dimensional finite element (FE) method is used to calculate the major parameters, such as armature and excitation inductances, which are not only functions of rotor position, but also of armature and excitation currents. Moreover, in case of short-circuits, the variations of armature and excitation currents are often significant. This in turn leads to an important change in winding inductances. Therefore, in order to precisely predict machine performance under short-circuit conditions, the use of inductances versus rotor position and RMS currents is essential. With the obtained FE results, two MATLAB/Simulink-based models are established. Then, the previously mentioned short-circuits have been studied and their influences on electromagnetic performances, such as armature and excitation currents, speed and torque, armature and excitation copper losses, stator and rotor core iron losses, as well as permanent magnet (PM) eddy current losses are analyzed. Experiments have been carried out to validate the simulations. [ABSTRACT FROM PUBLISHER]

In this paper, an analytical method for the computation of the electromagnetic field in the airgap of an inset permanent magnet synchronous machine is proposed. The originality lies in the fact that both the stator and rotor saliencies have been taken into account in the analytical procedure. The purpose in to compute both quickly and accurately the magnetic fluxes and instantaneous torque of the machine, in order to minimize torque ripples in an optimal predesign process. It is shown that the instantaneous torque is in good agreement with finite element results, for a shorter computation time. The model presented here can be used when the 2-D approximation of the machine is valid, which is the case for most of machines' topologies. [ABSTRACT FROM AUTHOR]

This paper presents 3-D finite-element analysis of a new double excitation synchronous machine. It is shown that the machine has true field regulation capability. The principle of operation and design aspects of this new machine are presented in the paper. Comparison of 3-D FEA with an experimental study done on a prototype having a different rotor structure is also investigated. [ABSTRACT FROM PUBLISHER]

This study presents a fault-electromagnetic-thermal model of a fault-tolerant dual-star flux-switching permanent magnet motor. The analytical results in terms of phase currents, rotor velocity and output torque are firstly calculated by a Simulink-MATLAB-based fault (short-circuit) model. Then, the fault and normal phase currents are used in the motor 2D finite element method (FEM) model to calculate the copper and iron losses. As the main heat sources in electrical machines, the obtained copper and iron losses are used in the lumped parameter (LP) and the 3D FEM thermal models to calculate the temperatures of different machine components. Finally, the variation of temperatures of the machine in the presence of faults can be predicted. The results obtained by the LP and the 3D FEM models are also validated by experimental tests. A good agreement has been observed among the analytical, numerical and experimental results. In order to realise the 3D FEM model of the doubly salient rotating machine, a method to transform the salient rotor into a non-salient one have been proposed. Some methods are also proposed to enhance the performance of the cooling system and decrease the maximum temperature of the machine. [ABSTRACT FROM AUTHOR]

This paper presents copper and iron loss models of a classical switched reluctance motor (SRM) and a mutually coupled switched reluctance motor (MCSRM). The iron losses in different parts of machines are then detailed. Based on the power losses model, a lumped parameter (LP) transient thermal model during driving cycles is performed, the analytical results are validated by the finite-element (FE) transient thermal model. Special attention has been paid to model the salient rotor and a method to transform the salient rotor into a nonsalient one has been proposed. A comparison between the maximum temperatures obtained by using different heat source (average power losses or instantaneous power losses during driving cycles) is given. The experimental tests are also realized to verify the analytical and numerical results. [ABSTRACT FROM PUBLISHER]

We describe a 3-D analytical model based on formal resolution of Maxwell's equations of a permanent-magnet linear actuator, with circular-shaped magnets. We present all details of the 3-D analytical calculation for the no-load flux and then compare results obtained by this model to those obtained by 3-D finite-element analysis. The comparisons show a good agreement between the two models and so validate our analytical model. Unlike 3-D finite-element analyses, which are time consuming, the analytical models that we present in this paper are suitable for an optimization process of such a structure. [ABSTRACT FROM AUTHOR]

In this paper, an analytical method for the calculation of the electromagnetic field in the airgap of a permanent-magnet synchronous machine is developed, so as to compute the torque of the machine. Such a work is applicable to different machine topologies (even for salient rotor ones), when a two dimensional approximation of the structure is possible. This analytical model can be useful in an optimization task. In the first part, the analytical method of the field computation is explained in detail, both for the magnet's field, and for the armature reaction field. The results are compared to finite elements analysis. [ABSTRACT FROM AUTHOR]