Efficiency Analysis of Axial Flux SynRM in Variable Speed Applications

Abstract

Electrical machines find their place in every field, such as industrial, transportation, home, and commercial sectors. The suitability of the electrical machine for the area in which it will be used is important in terms of energy efficiency. The selection of the motor to be used for variable speed applications such as electric vehicles is also very important. Torque and power are the determining factors in the required speed/torque or speed/power combination for electric vehicles. For this reason, the efficiency map of the motor to be used in electric vehicles should be known in detail. In this study, due to its advantages such as its lighter structure, absence of magnet, and rotor winding loss, among others, the Axial Flux Synchronous Reluctance Motor (AF-SynRM) was preferred, and it was aimed at creating an efficiency map. The motor parameters for the determined speed/torque combinations were first obtained with FEM. Then, the FEM results were experimentally verified. In order to make the obtained results more meaningful, the experimental results were compared with radial flux motors with the same output power. In addition, using FEM, von Mises stress analysis and displacement analysis were performed on the motor shaft under overload conditions to observe the mechanical effects on the moving parts of the AF-SynRM. Furthermore, mechanical load analysis on the bearings was also performed. The results show that AF-SynRM can be preferred as an alternative to other motor types, especially for applications requiring variable speed, such as electric vehicles. The study has created the efficiency map of the AF-SynRM topology for the first time.

Keywords

• axial flux
• synchronous reluctance
• efficiency map
• variable speed