Advanced design of direct drive PM machines

The following thesis takes into consideration some aspects regarding the design of permanent magnet machines. The growing interest in this type of emachines is due to certain characteristics that they present: high torque density, possibility of eliminating the gear-box and then subsequent reduction of costs and maintenance, etc.. Many applications are found in the field of wind generators, electric traction and rope traction. The special construction of such machines, such as the presence of fractional-slot windings, the large size and large powers that they may present, lead to the need of considering some issues often not properly investigated during the machine design. To this aim, the thesis examines the following two aspects: the rotor losses in machines with fractional-slot windings and the fault tolerance.