Electromagnetic fault analysis for high specific power permanent magnet synchronous machine

This thesis discusses the electromagnetic fault analyses for a high specific power 1 MW permanent magnet synchronous electric machine designed for aerospace applications. As the high specific power of 13.3 kW/kg of the machine is to be achieved by pushing the design parameters such as mechanical speed, electric current, and temperature, the importance of permanent magnet demagnetization and long-term insulation quality is stressed. Demagnetization will be quantified using finite element methods, where the effects of permanent magnet material, air gap, and rotor back yoke material on demagnetization will be explored respectively. This is expected to provide insights to the machine designers to select appropriate materials and air gap, topics that have not been yet covered in previous work related with the particular design. Ultimately, this discussion will lead to an electro-thermal trade-off problem since permanent magnets are highly sensitive to temperature. Secondly, this thesis discusses the insulation aging to determine the longevity of the design. Various aging models therefore will be introduced to provide an analytical basis to project the insulation lifetime on real applications. A preliminary aging experimental setup is presented, along with a partial discharge detection setup since partial discharges are suspected to be one of the main electrical aging mechanisms. Ultimately, the data obtained from the experiments must be fitted into the aging models. This thesis will present early experimental results