Torque-Speed Characteristic Improvement in Nineteen-phase Induction Machine with Special Phase Connection

Multiphase induction machines are advantageous regarding speed range extension in comparison with three-phase induction machines. This paper investigates how to choose the connection between stator phases for a multiphase induction machine allowing to extend the Torque-Speed characteristic of the machine, for traction application. A nineteen-phase induction machine with special phase connection is proposed. This topology is compared to a three-phase machine, with the same global volume, using a Finite-Element approach. The results show a significant extension of the Torque-Speed characteristic horizontally, by speed range extension, and vertically, by maximum torque enhancement, thanks to the pole-changing operation with the chosen phase connection.