Lionel Calegari

Synchronous reluctance machine flux barrier design based on the flux line patterns in a solid rotor

The paper focuses on the synchronous reluctance machine rotor design. The rotors shape in this machine should maximize the flux passing in the d axis while minimizing the flux in its q axis. This can be achieved by designing the rotor to respect the natural flow of the flux in the d axis in order to reduce the magnetic resistance while increasing the insulation in the q axis. The proposed design method in this paper is based on determining the analytical equation of the flux lines through a solid rotor. The analytical equation will allow the definition of the optimal curvature of the flux barriers. In a second phase, the width of the flux barriers is determined on the basis of the flux preservation theory in every flux segment. A comparison study using a finite elements simulation will allow us to validate the proposed approach.

Loss Minimization of an Electrical Vehicle Machine Considering Its Control and Iron Losses

In this paper, optimization of the control of an electrical machine allowing a minimization of its total losses is described. It is based on the use of an iron loss model [loss surface (LS) model] coupled to the electromagnetic finite-element simulations of the machine. The LS model is a scalar and dynamic hysteresis model developed many years ago at G2Elab and tested for iron loss prediction in several cases of electric machines. It is first characterized and improved in this paper for M330-35A SiFe sheets. Then, it is associated with a finite-element analysis to compute, in a post-processor mode, the local and global magnetic losses in the machine. For electric vehicle application, the whole torque-speed variation should be investigated. To do that, a quick response surface is constructed from a small number of simulations and the iron loss is determined. Then, a suitable optimization algorithm is developed. This approach is then illustrated by a case study and compared with classical optimization in which only the copper losses in conductors are considered. Gains of up to 50% reduction in the total losses of the machine in certain operating areas are observed.

Citation in machine

This paper describes a method to study the electrical steels with regard to their application. This methodology attempts to link the design of the electrical machine with the practical magnetic material behavior thanks to visualization tools. Firstly, some magnetic characterization are presented to determine the electrical steel behavior and to validate the hypotheses and the model considered. Then, the methodology and visualization tools are exposed. As a result, useful information is extracted to help the experimenter to dimension the characterization bench and to define the maximum frequency to be measured in order to have the best representation of the material behavior within the application.

Ultrasensitive polarimetric torque sensor

We propose the study and the design of an ultra sensitive polarimetric torque sensor. The principle is based on the measurement of the torsion angle (theta) induced on the shaft when a torque T is applied on it. This optical torque sensor has been tested for aluminum, steel and Plexiglas shafts with different geometries. The torsion angle has been measured with 0,001 degree(s) accuracy. The torsion angle is then studied as a function of the applied torque. The comparison between the theoretical and the experimental results give us respectively 4,33%, 1,30% and 1,24% for the Plexiglas, the aluminum and the steel shafts. These results permit us good perspectives for our applications.

New nondestructive optical method for measuring the rigidity modulus of solid materials

We propose a new optical method for the determination of the rigidity modulus G of solid materials. With this method, the rigidity modulus is determined by measuring of the twisted angle (theta) of the material, depending on an applied force. The measuring of this twisted angle is obtained by using an ultra sensitive polarimetric sensor. The effective measurement of rigidity modulus G for Aluminum and Plexiglas are experimentally achieved, we obtained respectively 1,44464.1010N/m2 and 0,99417.109N/m2.