François Peyraut

Multiphysics Finite-Element Modeling for Vibration and Acoustic Analysis of Permanent Magnet Synchronous Machine

This paper aims to describe a numerical modeling process for estimating the electromagnetic noise radiated from a permanent magnet synchronous machines. The original contributions concern the inclusion of a complete evaluation of the electromagnetic forces acting on the stator teeth, a complete 3-D structural finite-element model and a point wise approximation for acoustic calculation. Structural and acoustic responses of the targeted machine have been derived and validated using experiments. Superior precision of the proposed method has been substantiated through experiments.

Fast Computation of Electromagnetic Vibrations in Electrical Machines via Field Reconstruction Method and Knowledge of Mechanical Impulse Response

The main objective of this paper is to provide an efficient computational model for fast and accurate calculation of electromagnetically induced vibrations in electrical machines. Although a three-phase permanent-magnet synchronous machine has been used in this paper, the same methodology can be extended to other types of electric machinery. A brief comparison between the different methods for structural analysis in electrical machines is introduced. The method proposed in this paper uses finite-element analysis in order to extract the impulse responses that are used in calculating the vibration. A field reconstruction method is used for the electromagnetic field analysis.

Solution of large deformation contact problems with friction between Blatz-Ko hyperelastic bodies

The present paper is devoted to the analysis of the contact problems with Coulomb friction and large deformation between two hyperelastic bodies. One approach to separate the material nonlinearity and contact nonlinearity is presented. The total Lagrangian formulation is adopted to describe the geometrically nonlinear behavior. Nondifferentiable contact potentials are regularized by means of the augmented Lagrangian method. Numerical examples are carried out in two cases: rigid-deformable contact and deformable-deformable contact with large slips. The numerical results prove that the proposed approach is robust and efficient concerning numerical stability.

Active Mitigation of Electromagnetic Vibration Radiated by PMSM in Fractional-Horsepower Drives by Optimal Choice of the Carrier Frequency

A novel approach to quickly evaluate the electromagnetic vibration emitted by a permanent-magnet synchronous machine in A fractional-horsepower drive is detailed. Field reconstruction method and mechanical impulse response are used. The impulse response for rapid evaluation of vibrations at critical points is used after the design of a torque and speed controller. The vibration obtained using a three-phase pulsewidth-modulation technique and nonclassic space-vector modulations are compared by simulation results. An optimal choice of the carrier frequency, by an optimization method, for the two modulation techniques allows for a 35% reduction of the vibration in the targeted machine under different operating conditions. The peak-to-peak force-magnitude reduction reaches 8%.

A new based error approach to approximate the inverse langevin function

In the present paper, we propose a new approximation of the inverse Langevin function. This new approximation is based on a two-step modification of the fractional formula introduced by (Cohen 1991). Our proposal is motivated by the minimization of the error between the Cohen formula and the inverse of the Langevin function. It results in two additional terms adopting a remarkable simple power and polynomial forms. The correction provides an excellent agreement with a maximum relative error equal to 0.046 % (against a maximum error of 4.94 % for the Cohen formula).

A New Passive Methodology for Reducing the Noise in Electrical Machines: Impact of Some Parameters on the Modal Analysis

This paper presents a 3-D finite-element modal analysis to reduce the acoustical power radiated by a brushless permanent-magnet synchronous machines and avoid any resonance phenomena. The method is able to analyze the impact of some design parameters on all the resonance frequencies for reducing the total sound power and gives some guidelines to their choice. A less noisy prototype has been analyzed in simulation without any acoustic calculation and then built and validated with experimental results.

A new passive methodology for controlling the noise in electrical machines: Impact of some parameters on the modal analysis

This paper presents an initial state of the art about the most important techniques for reducing noise in an electrical machine. The FEM 3D modal analysis (realized with the software Ansys 11.0) is then proposed to study and reduce the acoustical power radiated by a brushless machine and avoid any resonance phenomena. The method is able to analyze the impact of some design parameters on all the resonance frequencies for reducing the total sound power and gives some guidelines to their choice.

New Estimation of Electromagnetic Sound Power Radiated by a PM Machine: an Active and Passive Control Guideline

This paper presents an initial state of the art about the estimation of the sound power emitted by electrical machines. The paper proposes a new method, more accurate, to evaluate the sound power emitted by a PM machine by a 3D FEM mechanical analysis. It also takes into account tangential forces applied on the teeth. Finally the papers shows the impact of any harmonic force in the global emitted sound power in order to establish the most disturbing force. It proposes a guideline for active and passive noise control.

Loading restrictions for the Blatz–Ko hyperelastic model—application to a finite element analysis

Abstract In this paper, we consider the Blatz–Ko constitutive model for compressible elastic solids. It is shown that the Cauchy stress tensor leads to a normal loading limitation. This limitation induces slow convergence of the Newton–Raphson algorithm near the maximum authorized normal loading value and divergence if this value is exceeded. In addition, convergence of the Newton–Raphson scheme also depends on ellipticity and strong ellipticity conditions. These various points are discussed in the case of a rectangular specimen subjected to a tensile load and modeled with finite elements.

Orientation preservation and Newton–Raphson convergence in the case of an hyperelastic sphere subjected to an hydrostatic pressure

Abstract In this paper, we show that the incremental Newton–Raphson algorithm diverges if the orientation is not preserved. To illustrate this point, we treat the example of a compressible hyperelastic sphere subjected to an hydrostatic pressure. The selected model is the Blatz–Ko behaviour law. We also show that it is possible to choose an optimal step loading. This step guarantees at the same time the orientation preservation, the Newton–Raphson convergence and a minimum computing time.