Experimental performance verification of radial and axial flux line start permanent magnet synchronous motors

Abstract

Recently, more power in a smaller volume is demanded from electric motors for next-generation applications. For this reason, permanent magnets are preferred in motor design. Although the use of magnets provides some advantages, it also has disadvantages such as designing difficulty and not starting directly from the line. However, by placing permanent magnets in the rotor of induction motors, which are widely used in the industry, line start Permanent Magnet Synchronous Motors (PMSMs) that can start from the line and continue to operate at a constant speed can be designed, in addition to their robustness and simplicity. With these motors which allow more power and higher efficiency to be obtained from the unit volume, the load and speed requirements of applications such as fans, pumps, and conveyor systems, which are widely used in the industry, can be provided without costly drivers. In addition, with the axial flux and radial flux topologies obtained by changing the flux direction for these motors, superior operating performance can be achieved, and material consumption can be minimized. In this study, the performances of two line start PMSMs with axial flux and radial flux, which have been prototyped and tested with a 4-pole 5.5 kW shaft power that can be driven directly from the line, are experimentally compared. The motor design parameters of both motors are also included in the comparison and the results are presented in detail. Both motors compared are prototyped motors for the first time, especially the axial flux structure is a structure that has been experimentally tested for the first time in the literature with the line start feature of the axial flux structure PMSM. The radial flux PMSM, on the other hand, has a hybrid slot structure, which has been applied for the first time in this field. The experimental comparison of these original structures for the first time in the literature constitutes the originality of this study.