The Structure Optimization of IPM Synchronous Machine

The non-magnetism bush of IPM synchronous machine can efficiently reduce the leakage flux near shaft. However, it brings two defects which make the structure of the machine complex and the usable space of the PM reducing. This paper studies the non-magnetism bush of IPM synchronous machine, and then discusses the influence on machine performance when auxiliary pole was introduced, and it also presents the restriction condition of the magnet width in given condition and compares the air gap flux density and the per pole flux in two conditions which the shaft material is magnetism or non-magnetism, by neglecting the non-magnetism bush and auxiliary magnet when the magnet width reaches maximum. From that, we can draw conclusions as follows: (1) Not only does the introduction of the auxiliary pole lead to the removal of the non-magnetism bush but also the improvement of machine property; (2) Given constant figures of machine diameter and magnet thickness, the machine performance can also be improved when magnet width reaches maximum value while non-magnetism bush is removed.