The optimization of rare earth magnet thickness of IPM synchronous machine with "flux concentration function"

This paper presents the restriction condition of the rare earth magnet thickness in IPM synchronous machine. The rare earth magnet thickness of IPM synchronous machine was restricted by pole pairs, rotor diameter, rare earth magnet width as well as non-magnetism bush thickness. Under the air gap length be constant, it analyzes the relation between the rare earth magnet thickness and air gap flux density, and the per pole flux respectively; at the same time in order to keep leakage flux constant, under the air gap length variety, it discusses the relation between air gap length and the non-magnetic bush thickness, and the rare earth magnet thickness respectively, then point out: (1) the rare earth magnet thickness of IPM synchronous machine was restricted by pole pairs, rotor diameter, rare earth magnet width as well as non-magnetism bush thickness; (2) as the increase of the rare earth magnet thickness, the function of magnetism potential provided through the rare earth magnet volume increase of 4, 5, 6 pole pairs is different respectively; (3) in order to keep the leakage flux unchanged at non-magnetism bush, the thickness of non-magnetism bush should be increased; (4) the thickness of non-magnetism bush should have a suitable value with increase of air gap length.