Identification et prévision du comportement dynamique des rotors feuilletés en flexion

Guillaume Mogenier 1
1 DCS
LaMCoS - Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne]
Abstract : This Ph.D. thesis deals with the prediction of the dynamic behavior of induction motors and especially with the lateral dynamics of squirrel cage laminated rotors known as high speed motor (HSM, [3 − 30] MW, [6 000 − 18 000] rpm). The main difficulty of the modeling is due to the complexity of the HSM magnetic mass assembly, composed of a core of laminated steel held by excentric prestressed tie rods, and a squirrel cage consisting of a distribution of short-circuit rods also positioned at the periphery of the magnetic mass and connected to two short-circuit rings located at the ends of the laminated core. A finite element model of Timoshenko beams is developed that takes into account the monolithic nature of the HSM rotors. A particular attention was given to the modeling of the magnetic core by considering either the short-circuit rods and the tie rods, the latter being independently modeled of the lamination stack. The lateral behavior of laminated rotors is mainly governed by the bending rigidity of the stack whose constitutive properties are unknown and directly related to manufacturing process of the electrical machine which makes the modeling of HSM rotors difficult. The stated finite element model provides the stress in the finite elements. The mixed numerical-experimental procedure provides the evolution of the constitutive properties of the lamination stack depending on the geometry and prestressed assembly. For this, predicted and measured modal quantities (either in the manufacturing site of Champigneulles, France or in laboratory) are included in an energy functional based on a hybrid Rayleigh quotient combined with eiher Guyan or Craig & Bampton reduction methods, or Guyan or SEREP expansion methods. All the proposed functionals have been tested in various industrial applications in order to identify constitutive properties of real structures : lamination stack, shaft ends or rotor of active magnetic bearing. The development of Levenberg-Marquardt or eigen elements derivation algorithms were necessary to minimize the functional, extract the constitutive properties of the stack and predict mode shapes and natural frequencies as close as possible possible of the measurements at rest. The modeling of the centrifugal loads, geometric stiffness and tie rods/stack contact have shown that the rotation effect has a non linear influence that tends to increase the axial forces acting on the stack and the tie rods without exceeding their yield stress. The consequence of this effects is the increase of the bending rigidity of the magnetic core when the electric motor rotates. The control of the laminated rotor dynamics as well as the knowledge of equivalent constitutive properties of the lamination stack, the squirrel cage assembly or the tie rods centrifugation, increase the reliability of the prediction, especially in the development phases of laminated rotors never built before, eg 30 MW 6 000 rpm.
Document type :
Theses
Mechanics [physics.med-ph]. INSA de Lyon, 2011. French. <NNT : 2011-isal-0030>


https://tel.archives-ouvertes.fr/tel-00627647
Contributor : Guillaume Mogenier <>
Submitted on : Thursday, September 29, 2011 - 11:26:35 AM
Last modification on : Wednesday, October 29, 2014 - 1:23:10 PM

Identifiers

  • HAL Id : tel-00627647, version 1

Collections

Citation

Guillaume Mogenier. Identification et prévision du comportement dynamique des rotors feuilletés en flexion. Mechanics [physics.med-ph]. INSA de Lyon, 2011. French. <NNT : 2011-isal-0030>. <tel-00627647>

Export

Share

Metrics

Consultation de
la notice

469

Téléchargement du document

210