Design and optimization of a 9-phase induction machine

The intense growth of electric transportation demands new standards in electric systems' reliability and fault tolerance. Alternative solutions to the standard 3-phase machines have been studied in literature to ensure these characteristics. It has been observable that multiphase machines can provide reduced power per phase, lower torque pulsation, higher reliability, and power density. This thesis aims to develop a 9-phase induction motor (IM) as an alternative to the already studied machines based on permanent magnets. After some initial considerations on multiphase systems and the best winding layout, a first design of the 11 kVA IM is proposed, based on the given design specification and criteria. In the following chapter, optimization through a genetic algorithm is performed to maximize the motor's performance and characteristics such as efficiency, reliability, and weight/dimensions. A rated torque of T = 28.5Nm and an efficiency η = 89.9% are obtained. Finally, a Finite-Element-Analysis (FEA) is executed to gain more detailed knowledge about the optimized machine and it is compared to the results of analytical calculations with optimum outcome.