Calculation and measurement of electromagnetic parameter for high speed slotless PM motors

This paper presents a analytical model for calculating the electromagnetic parameter of slotless permanent magnet (PM) motors. The load magnetic field in the machine can be divided in two parts: the magnetic field produced by PM, the magnetic field produced by winding current. Two analytical models are deduced separately based on the Maxwell´s equations. The load magnetic field obtained ultimately using the superposition theorem. The electromagnetic parameter such as electromotive force (EMF) and torque are calculated based on the solution of the magnetic field. The test results verified the accuracy of the analytical model.