Application109 Motor with Polar-Anisotropic Ring Magnet

General
The anisotropic ring magnet technology is greatly expected to contribute to the development of compact, high-performance, and easy-to-assemble motors.
This example analyzes the torque of a motor having a polar-anisotropic ring magnet.

Analysis Model
The model represents a surface permanent magnet (SPM) motor having 4 poles and 24 slots.
It includes a rotor composed of a polar-anisotropic ring magnet and does not include a core in the inner area because the Halbach array magnetic circuit structure eliminates flux leakages to the inner area.
With the external circuit coupling, the input is set by current values, and the model is analyzed.
The model is quarter-periodic symmetric and 2D for less calculation time.

Result
The electric current-specified source allows for the waveform of torque in a steady state starting from 0 degrees. The torque waveform, plotted versus rotation angles, features little torque ripples.
The phase of U-phase is determined by utilizing the result obtained from the function of [Search for power phase at the maximum torque]. Even though torque varies depending on the power source phase, the function can determine the power source phase to maximize the torque in a short time. (Magnetic-transient analysis)
The magnetic fields generated by an array of magnets can be analyzed in the magnetic-static analysis. The results indicate that the polar-anisotropic ring magnet allows magnetic flux lines to concentrate on its outer diameter side with few magnetic flux lines on its inner diameter side.
The surface magnetic flux density on the outer circumferential surface has a characteristic sinusoidal waveform.