Efficiency Improvements of an Axial Flux Permanent Magnet Motor

Abstract

NovaMax® motor is an axial flux permanent magnet (PM) motor which incorporates several unique topologies to achieve state-of-the-art efficiency of 96%. The use of grain oriented electric steel (GOES) increases permeability along the axial flux path; the use of soft magnet composite (SMC) allows rotor flux to be concentrated from all directions; and the use of conical air gap increases the surface area of the air gap and, thus, increases total magnetic flux. While the NovaMax is one of the most efficient permanent magnet motors on the market, the goal of this research project is to optimize the current NovaMax’s design to further reduce the motor loss by 20%.

This project consists of two phases. First phase is to develop a parametric 3D finite element analysis (FEA) model of the current motor. In order for the model to accurately predict the motor behavior, a set of experimental testing of the current NovaMax motor is conducted for results comparison between the simulation and testing. Additionally, an air gap study motor, in which the air gap can be changed, is tested to further correlate the ANSYS model to the actual motor.

Second phase is the motor efficiency improvements using FEA model developed. A set of new design changes including new motor geometry and change in magnetic material have been proposed and tested in the FEA model. After adoption of some proposed ideas, the motor loss is reduced by 20.9% compared to the current motor.

While working on this research project, the cost and manufacturability are also considered to allow this motor to be commercialized for energy saving across the country.