Research Of A Multistage Axial Flux Permanent Magnet Machine

In the 21 st century, energy and environmental protection have become the two major bottlenecks for economy sustainable development. Development of new energy electric vehicles is an important direction to achieve our energy security, environmental protection and sustainable development of the automotive industry. Electric motor is one of the key parts of new EVs. Because of high torque/power density, excellent thermal performance and compact structure, the axial flux disc permanent magnet machine is concerned widely. Therefore, in this paper, there are a series of studies on a multistage axial flux permanent magnet machine for EVs. And these studies can be divided into two parts, theoretical simulation and practical operation.Firstly, the existing topologies of axial flux permanent magnet machines are analyzed and the main object of this paper,Torque-NS multisage axial flux permanent magnet machine which has three rotor-discs and two stator-discs, is introduced in detail. Meanwhile, a novel axial-radial flux disc machine is also proposed and introduced in brief. Then, the electromagnetic design and PM's common problem pulsating torque are studied. Using theoretical and finite element method(FEM), to prove the effectiveness of bidirectional magnet skewing technique in minimizing pulsating torque. Finally, the electromagnetic scheme is analyzed by FEM. Using Ansoft Maxwell 3D to conduct electromagnetic simulation. FEM results show that the electromagnetic scheme is feasible.This paper uses ANSYS and Solidworks to do thermal and mechanical strength verification respectively. FEM results show that the architectural design is feasible. In order to manufacture prototype machine, a complete set of manufacturing and assembly program is developed in this paper. Finally, some experiments are conducted on the prototype, including open back-EMF test, variable frequency test, variable load test and cogging torque measurement. Experiment results prove the relative theory, to achieve the established requirements.