Design and Performance Evaluation of a Novel Axial-Flux Hybrid Motor With Permanent Magnet Rotor and Unpaired Damper Cage

In order to improve the performance of synchronous motors, especially in dynamic-transient conditions, induction damper cages are usually used in the rotor structure. In this paper, a new hybrid structure of an axial-flux motor is proposed, which uses a permanent magnet (PM) rotor and an unpaired induction damper cage with independent movement capability. The proposed motor design procedure is provided in some detail. The performance of the proposed motor is evaluated using the finite element method (FEM) simulation and the operational effects of the unpaired damper cage are evaluated. In addition, comparisons were made between three different motor structures including the structure without damper cage (WDC), the structure equipped with coupled damper cage (CDC), and the structure equipped with unpaired damper cage (UDC) (proposed structure). Dynamic-transient and steady-state characteristics of motors including current profile, torque, and speed are evaluated. In order to confirm the results of the FEM simulations, a prototype of the proposed motor is manufactured, and some functional tests were performed on it. The results show that the proposed new structure can have better dynamic performance than other structures in terms of the amplitude of fluctuations as well as the time to reach the steady-state.