Design and Analysis of Coreless Axial Flux Permanent Magnet Machine with Novel Composite Structure Coils

Abstract

In this paper, a type of novel composite structure coil applied in the coreless stator is proposed and studied to improve the output performance and efficiency of the axial flux permanent magnet (AFPM) machine. In which the effective conductor is changed to be wedge-shaped by the rolling technology so that the turns of coils and filling factor can be further increased, and the ends are kept in the cylinder with a larger diameter to reduce the DC copper loss. Meanwhile, the air region between the double rotors of the machine is also modified to be wedge-shaped, which fully matches the proposed coils and shortens the air gap length. The advantages of performance can be verified by the three-dimensional (3D) finite element analysis (FEA) and analytical method so that the output characteristics of no-load and load can be improved, and the DC copper loss and eddy current loss of coils can be reduced. The coreless AFPM machine finally performs a high efficiency of 95.34% according to these valuable optimizations.

Design, Analysis and Experimental Verification of a Coreless Permanent Magnet Synchronous Motor

“…During the measurements, the rotor rotated at 2150 rpm and was loaded with a torque of 0 to 3.51 Nm. The test bench for the motor load test is shown in Figure 12, with a converter (1) to supply the motor under test (2), an MT5 torque sensor to measure torque and speed (3) and an eddy current brake (4). Measurements of electrical quantities were performed using a class A power quality analyser.…”

“…These machines, in relation to machines with a core, are characterised, among other things, by lower unit costs, no cogging torque and low winding inductance. Furthermore, due to the lack of a laminated steel sheet core, less waste is generated in the production of these machines, and at the end of their useful life, it is easier to dispose of and recover useful materials [3,4]. An increasing number of articles, for example [1,5], have presented the results of research related to the development of new designs of electric machines for specific applications.…”

Ultra‐fast finite element analysis of coreless axial flux permanent magnet synchronous machines

“…The analysis of skew angle, overhang, or end coils in machines with 3D flux pathways, such as axial flux PM machines (AFPM), has revealed that 2D models and analytical methods are not sufficiently accurate [7,[11][12][13][14]. A detailed modelling of the machine is required in any case to study the eddy current losses in the stator winding.…”