Thermal Analysis of Multiphase Induction Motor for Electric Vehicle Applications

Induction motors has been widely used in industrial as well as automotive application because of its low cost, mature technology, and rugged construction. Polyphase induction motors offer additional advantages over three-phase induction motors such as fault-tolerant operation, an additional degree of freedom, less torque ripples. This paper presents the modeling and thermal analysis of a totally enclosed fan-cooled six-phase induction motor for electric vehicle applications. A coupled model design with electromagnetic and thermal analysis of an asymmetrical six-phase induction motor is explained. The motor is designed using the machine equations and the electromagnetic analysis is done in Maxwell 3D. The steady-state and thermal analysis can be done using CFD or Motor CAD.The Maxwell 3D geometry is imported into Ansys motor CAD for thermal analysis. Depending upon the parameters, cooling, and material a multi-node thermal network consisting of thermal resistance, capacitance, and the heat source is obtained. The transient and steady-state temperature variation of the six-phase induction for the rated load condition is analyzed.