Travail de fin d'études et stage[BR]- Travail de fin d'études : Analytical model of an electromagnetic linear actuator and its design optimisation[BR]- Stage d'insertion professionnelle

Abstract

This Master’s Thesis aims to produce a tubular permanent magnet actuator (TPMA) design capable of replacing the hydraulic dampers present in active train suspensions. This design needs to be optimised to provide the best possible performance. In the first part of this thesis, a state of the art of the available TPMA topologies is presented as well as their operating principle. In the second part the analytical model of each topology is developed in order to obtain the behaviour of the magnetic flux within each actuator. This model contains the solution of the Laplace and Poisson equations from Maxwell’s equations. The specific boundary conditions for each of the topologies are exposed in order to obtain the specific solutions. Then the results are compared in order to keep the best topology for the rest of the thesis. The third part is devoted to the modelling of the thrust produced by the actuator. The thrust produced by the actuator is dependent on the type of current injected. Thus three types of current are compared: single-phase, two-phase and three-phase. The fourth part concerns the optimisation of the actuator design. In a first step, the optimisation is done by the particle swarm optimisation (PSO) method. This first optimisation has only one objective, to maximise the thrust produced by the actuator. The dimensions to be optimised are the radii of the actuator and the pole pitch of the magnets. In a second step, a new objective, that of minimising the force variation, is added to the optimisation. This multi-objective optimisation problem is solved using a method derived from PSO: vector evaluated particle swarm optimisation. Finally, the different designs obtained by the two optimisations are compared. The last part is devoted to the presentation of some improvements that could be made to the analytical model of the actuator to make it even more accurate.