Researchers create 3D analytical model for AFPMs

Axial-flux permanent magnet motors (AFPMs) could be used as a potential next-generation mobility device due to their advantages, such as flat geometry, low energy consumption, high efficiency, and high torque. Researchers at Epson have developed a 3D analytical model for AFPMs with an arbitrary number of poles and arbitrary arrangement of the permanent magnet (PM). Details of the model were published in the journal IEEE Access.

The AFPM is a class of PM-synchronous motor in which PMs are periodically arranged on the plane of rotation such that magnetic fields are aligned parallel to the rotation axis of the machine. In contrast to the ordinal radial-flux PM motors, which are already in widespread use, the AFPM has the potential for realising flatter geometry, among other benefits. The AFPM’s combination of high-performance and convenient form factor is expected to find use in various industrial areas, such as servo-actuation for multi-joined robot arms, and in-wheel drive for future electric vehicles and other mobility devices.

Development of devices that achieve the full potential AFPM has thus far been hampered by insufficient simulation technologies: researchers have been forced to choose between using 2D models with simple PM arrangements that provide a poor approximation of real devices or using commercial simulation software, which requires lots of computation time.

In response to the lack of adequate simulation tools, researchers developed the 3D analytical AFPM model that accommodates an arbitrary number and configuration of magnetic poles. The model includes the number of magnetic poles, variables expressing the configuration of the magnetic poles, the number of coils, device dimensions, and others. Physical phenomena in the motor can be analysed using the derived formulae. These findings are expected to contribute to the realisation of next-generation, high-performance and high-efficiency motors.

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