A new rotor design of interior permanent magnet machine suitable for wide speed range

The interior permanent magnet (IPM) machine is considered to be one of the most efficient electrical machines. The high efficiency along with good performance characteristic makes them suitable for drives with wide speed range. The typical IPM machine has almost nil or very little field weakening range. Many attempts have been made to improve the range by modification of rotor configuration. In this paper an attempt has been made to review different types of rotor configuration of IPM machine that is suitable for flux weakening operation. A new rotor design of segmented magnet has been studied by finite element (FE) analysis. The result of FE model of segmented magnet rotor and a conventional rotor of IPM machine has been compared and discussed. In the new design an improved flux weakening aspect has been noticed. Since the new design doesn´t need any special construction effort, it could be a better solution for IPM rotor configuration suitable for field weakening operation.