Sofiane Ouagued

Bio: Sofiane Ouagued is an academic researcher from University of Le Havre. The author has contributed to research in topics: Finite element method & Magnetic reluctance. The author has an hindex of 4, co-authored 7 publications receiving 76 citations.

Cogging Force Analysis of Linear Permanent Magnet Machines Using a Hybrid Analytical Model

Abstract: The aim of this paper is, first, to extend the application of the hybrid analytical modeling (HAM) approach for the analysis of tubular linear machines (TLPM), something that has never been reported yet in the scientific literature. The HAM consists of a strong coupling between the reluctance network and the Fourier series solution of magnetic scalar potential. In order to assess the merits and capabilities of the HAM, it is applied to the study of the cogging force in linear machines and compared with finite element analyses (FEA). The cogging force is a global quantity, which is very sensitive to magnetic field computation accuracy and constitutes, therefore, a good measure of the accuracy of the HAM as compared with FEA. The HAM should require less computation time as compared with FEA, and is then more suitable for predesign stage. Three different structures are analyzed: a flat linear machine, a TLPM with internal mobile armature, and, finally, a TLPM with external mobile armature. The analyses are conducted, considering the effect of magnetic saturation.

A general framework based on a new hybrid analytical model for the analysis and design of permanent magnet machines

Abstract: In highly concurrential markets the time to market is reduced, which implies a need of design tools having relatively high accuracy to computation time ratio. It is to address this problematic that the presented modelling approach has been developed. A general framework for the analysis and design of electromagnetic devices is presented. This framework is based on a new hybrid analytical model (HAM) [1]-[4]. The HAM can be applied to different electric machines types (synchronous and asynchronous) and structures (rotating with radial field or axial field, linear flat or tubular structures, or multi-degree-of-freedom structures). It is based on a direct coupling of analytical solution of Maxwell's equations (AM) with reluctance networks (RN). This new technique allows to combine advantages of both methods and should help reduce computation time as compared to finite elements method [3]. This modeling approach is relatively simple and allows the accurate prediction of performances of electromagnetic devices.

Thermal modelling of tubular linear machines using a hybrid analytical method

Abstract: The aim of this paper is to apply a hybrid analytical method (HAM) for the thermal modelling of tubular linear machines. This technique has been successfully applied for the electromagnetic modelling of electrical machines and it gives relatively good results as compared to finite element method (FEM). The HAM is based on the coupling of a macro-element, based on the analytical solution of heat equation, for the mechanical air-gap with a mesh based generated lumped parameter thermal model for the rest of the studied structure. In order to validate the proposed modelling approach, results issued for the HAM are compared to corresponding results obtained from a FE analysis. This modelling approach should constitute a useful tool for the pre-design of electrical machines.

Performance analysis of a series hybrid excited synchronous machine by a hybrid analytical model

Abstract: The aim of this contribution is to study the performance of a series hybrid excited synchronous machine by a new hybrid analytical model. The hybrid analytical modelling (HAM) approach, based on a direct coupling of analytical solution of Maxwell's equations with reluctance networks (RN), is compared to finite elements modelling (FEM), in term of results quality. Hybrid excited synchronous machines, due to their advantageous characteristics and performance, are good candidates in a large variety of applications: hybrid and electric vehicles, electric generation. The analysis of electromagnetic performance of this hybrid excited machine is also aimed at highlighting the capabilities of the HAM.

Analytical On-Load Subdomain Field Model of Permanent-Magnet Vernier Machines

Abstract: Permanent-magnet vernier machine (PMVM) is a relatively new type of PM machines. An analytical subdomain model accounting for tooth-tips and flux modulation poles is developed to accurately predict on-load field distributions in PMVMs. Based on two-dimensional (2-D) polar coordinate and magnetic vector potential, this method solves the Maxwell’s equations in slot, air-gap, flux modulation pole slot (FMPS), and PM regions. Consequently, the electromagnetic performance such as cogging torque, back-electromotive force (EMF), electromagnetic torque, power factor, and magnet loss are calculated. In addition, the model can also be used for the evaluation of demagnetization withstand capability. The finite-element analysis (FEA) and experimental results validate the accuracy of the developed analytical model.

On-Load Field Prediction in SPM Machines by a Subdomain and Magnetic Circuit Hybrid Model

Abstract: In this article, a new subdomain and magnetic circuit hybrid model (SMCHM) is proposed for on-load field prediction in the surface-mounted permanent-magnet machines. Equivalent current sheets are introduced to represent the nonlinearity effect, whose values are obtained by a magnetic circuit (MC) and correlated with boundary conditions in a subdomain model. The number of reluctances in the MC of the proposed model can be selected flexibly according to the nonlinearity effect. Instead of sectorial tooth in the conventional subdomain model, parallel tooth is considered in the proposed model to improve the accuracy. The SMCHM can accurately calculate the flux density distributions and electromagnetic performance considering the heavy nonlinearity effect under the load conditions with fast computation speed. The finite-element analysis is performed to validate the proposed model, which shows an excellent agreement between them. A prototype machine is manufactured to further prove these predictions.

A Simple and Efficient Quasi-3D Magnetic Equivalent Circuit for Surface Axial Flux Permanent Magnet Synchronous Machines

Abstract: This paper presents a simple and efficient magnetic equivalent circuit (MEC) model for surface axial flux permanent magnet synchronous machines. The MEC model is used to solve all the electromagnetic properties of the machine including the no load, full load voltages, cogging torque, torque ripple, and stator iron core losses. Moreover, this approach can be extended for all surface permanent magnet synchronous machines. The main novelty of this approach is the development of a static system, which accounts for the rotation. The model takes into account the rotor rotation via time-dependent permanent magnet magnetization sources. The static system matrix facilitates a very fast solving. In addition, to take into account the three-dimensional (3-D) effect, a multislicing of the machine in the radial direction is done. This boosts the simulation time to only 60 s for six slices and 50 time steps including the nonlinear behavior of the stator elements with a great accuracy. Additionally, the number of elements in the MEC can be adjusted to reduce the computational time. This model is verified by means of 3-D and two-dimensional (2-D) multislice finite-element models. In addition, experimental validations are also provided at the end.

New Scientific Contribution on the 2-D Subdomain Technique in Polar Coordinates: Taking into Account of Iron Parts

Abstract: The most significant assumptions in the subdomain technique (i.e., based on the formal resolution of Maxwell’s equations applied in subdomain) is defined by: Theiron parts(i.e.,theteeth and the back-iron are considered to be infinitely permeable, i.e., µiron → +∞, so that the saturation effect is neglected. In this paper, the authors present a new scientific contribution on improving of this method in two-dimensional (2-D) and in Cartesian coordinates by focusing on the consideration of iron. The subdomains connection is carried out in the two directions (i.e., x-andy-edges). Forexample,the improvement was performed by solving magnetostatic Maxwell’s equations for an air- or iron-cored coil supplied by a direct current. To evaluate the efficacy of the proposed technique, the magnetic flux density distributions have been compared with those obtained by the 2-D finite-element analysis (FEA). The semi-analytical results are in quite satisfying agreement with those obtained by the 2-D FEA, considering both amplitude and waveform.

An overview of analytical methods for magnetic field computation

Abstract: In this paper, several of analytical methods for modelling the magnetic field are described These models are used in design routines of the rotating machines, linear motors as well as actuators Thanks to their high accuracy and low requirements for computation power, they are successfully implemented in designing high precision machines In order to enlarge the applicability of the methods it is a common practise to combine two or more model such as Magnetic Equivalent Circuit (MEC) and Harmonic Method (HM), Schwartz Christoffel (SC) mapping and Tooth Contour Method (TCM), those combinations turns into so called Hybrid Methods which are also intended to increase the computation speed and results precision