High speed and angular position sensor for a permanent magnet synchronous motor control

Abstract

This thesis consists in developing a position sensor in order to control a perma- nent magnet synchronous motor (PMSM). It is the aim of an intership in the MITIS company. The company is developing micro-CHP (Combined Heat and Power) systems. These systems are mainly composed of a PMSM, a compressor, a combustor and a turbine. In fact, the open-loop control already implemented presents different issues of operating that need to be solved. For that, a closed- loop control is necessary for a better efficiency of the global system. This one needs an angular position sensor for its feedback information that is developed in this work. The choice of the sensor is an Eddy current sensor characterized for its low maintenance, its accuracy and its large range of rotation speed mea- surement. Indeed, for this project, a rotation speed of 120 000 rpm need to be reached by the motor. Moreover, it does not need a proximity with the magnet. This thesis is composed of different chapters. First, the concept of micro tur- bine, PMSM and its controller are presented. Then, a chapter that explain in details how the sensor had been designed and manufactured regarding the me- chanical and manufactured constraints. After, another chapter is dedicated to the software development of the sensor with the difficulties encountered such as the rapidity of data acquisition. Finally, a chapter about different closed-loop controls that could be implemented is established and the advantages and dis- advantages for each type of control are supported by simulations. Finally, some good results are obtained. The sensor is unfortunately not tested on a real motor but an experiment that allows to reach 5000 rpm is performed and is successful. Moreover, the choice of the speed and torque closed-loop con- trol is very promising regarding the results of the simulations with a very high speed reached (120 000 rpm) and a low consumption of the current in the stator windings (about 30A).