Increasing the air-gap magnetic flux density to generate a higher torque in permanent magnet synchronous machines

Abstract

The main objective of this thesis is to investigate the air-gap magnetic flux density and the torque output of a permanent magnet synchronous motor with embedded magnet rotors. In the beginning, variation of the air-gap magnetic flux density as a function of the magnet height has been investigated. Later, two rotor geometries have been investigated. One of the rotors has a dove-tail-shaped arrangement of magnets while the other has a U-shaped arrangement of magnets. The U-shaped magnets are oriented such that a Halbach array could be produced. Two-dimensional Finite Element Analysis was employed in the rotor geometry analysis. The results of variation in the height of magnet suggest that air-gap magnetic flux density saturates after certain height of the magnet. Similarly, the results show that the embedded magnets in the rotor with Halbach array orientation could produce a higher air-gap magnetic flux density in comparison to the embedded magnets in the rotor with only radial orientation of magnets.