Development and optimization of a novel homopolar starter-generator

The present work is primarily concerned with the development and optimization process of a novel generator, which is supposed to be more efficient, more reliable and to have a higher power density than existing ones. In the first part of the work different electrical machines which are suitable for an application as a starter-generator are described. A comparison study with focus on the machine application is made and the machine types most suitable for the mentioned application are indicated. Further chapters describe the calculation tools used in the project and the development process of heteropolar and homopolar machines. Several machine versions are presented. A machine design meeting the project requirements is sought. Chapters 6 to 12 describe the optimization process of the homopolar machine. In these chapters, the phenomena specific for the designed machine type including magnetic flux shortcut and axial forces are also explained. The influence of the rotor and the stator teeth width on the maximum torque and ripple is analyzed. In addition, solutions to the axial forces problem are proposed. A new machine model, taking into consideration the previously gained experience, is presented. In the final chapters, the calculation results are compared with the experimental results and discussed. The machine development process is summarized and conclusions are drawn.