Optimum design of a multilayer interior permanent magnet synchronous motor using reluctance torque

The report analyzes the results of experiments done with an inverter drive interior permanent-magnet (IPM) motor. We examine results of both FEM (finite element method) simulation and experiments using a prototype motor with identical conditions set for stator and magnet volume. The results indicated that with magnets implanted inside the rotor, the values for the d-axis inductance of the motor remained roughly the same, unaffected by the shape or number of layers. However, the q-axis inductance exhibited significant change. This research report compares an IPM motor having two layers of permanent magnets with a motor having a single layer. The dual layer shows a 30% or greater increase in torque using the same current. These results indicate that this motor is especially effective for such applications as robots, plant machinery, compressor motors, and electric vehicles. (C) 1999 Scripta Technica.