Self-bearing permanent magnet synchronous machine configurations and control for high-speed applications

In this thesis, the active self-bearing topologies relevant for high-speed motors are investigated. From the conventional double isolated winding topology toward more sophisticated winding configurations, two active self-bearing principles are examined. For each configuration, this thesis focuses on the modelling and the control aspects. The advantages and drawbacks, as well as the relevant field of applications are also addressed. The first part deals with the working principle of magnetic levitation force generation with superposition of field components. A qualitative comparison between self-bearing motors and magnetic bearings follows to present the fundamental differences between DC and AC based electromagnetic actuators. Since the drive is actively controlled, a revision of the relevant sensors for this particular application is given. Particular attention is given at the characteristic and limitations of the sensors. The modelling part follows with the analytical calculation of the motor electromagnetic model starting from the Maxwell equations. The non-linear torque and force components that act as disturbance on the model are also evaluated. A general position control scheme is then presented and derived with several feedback control. It is shown that, given an appropriate control reference frame, the mechanical control scheme is very similar to the one with magnetic bearings. Given that, the active self-bearing motor differs from its counter part with active magnetic bearing only from the electrical point of view. Then a double conical self-bearing motor is presented and modelled. A second self-bearing motor with split winding is presented. First the working principle as well as the control is detailed. The design and modelling is done for a prototype rated at 60 krpm and 0.66 kW. The prototype is then built and measured. Finally the presented controllers are experimented on a testbench. The design of the hardware and software parts is presented as well as the performances obtained with the double-conical self-bearing motor