Design and modelling of a two‐degrees‐of‐freedom dual‐rotor axial‐flux squirrel cage induction motor

Abstract

Abstract A two‐degrees‐of‐freedom (2DOF) dual‐rotor axial‐flux induction motor (2DOF‐DRAFIM) is proposed with independent movement capability of rotors and its performance is evaluated in detail. First, using the analytical equations, the steady‐state model of the motor is presented and the electrical equivalent circuit is extracted along with an electromagnetic design algorithm for the proposed motor. In the next step, using two‐dimensional and three‐dimensional finite element modelling (FEM), the performance of the proposed motor is investigated. The results of the experimental measurements on the manufactured prototype confirm the validity of the results of theoretical modelling and finite element simulations. The proposed structure provides some unique features. One of the fascinating behaviours of the proposed 2DOF‐DRAFIM is that the higher‐speed rotor produces higher output torque and the lower‐speed rotor has lower torque. In this regard, the 2DOF structure can be considered a potential concept for electric vehicles (EVs) without needing a conventional mechanical differential.

Keywords

• 2DOF motors
• axial‐flux induction motors
• equivalent circuit
• finite element method
• hybrid‐motion motors