Open circuit analysis of concentrated winding in interior permanent magnet machines with fractional slot distribution

The application of concentrated windings in interior permanent magnet (IPM) machines has been claimed to enhance high-speed performance by increasing flux- weakening capabilities of the machine. However this is at the expense of a higher cogging torque, decreased winding factor as well as saliency ratio. This paper illustrates the effects of implementing methods used to improve open circuit characteristics in surface permanent magnet (SPM) machines on interior permanent magnet (IPM) machines with concentrated windings. Theoretical results were proven by the use of finite element methods with flux 2D.