Performance comparison of different IPM motor topologies for spindle motor drives

In this study, six promising interior permanent magnet (IPM) motors are designed as a spindle motor for computer numerical control (CNC) milling machine application. An existing surface-mounted permanent magnet (SPM) motor in a CNC is selected for a baseline motor. In order to reach more high speeds as to SPM motor, six different IPM rotor topologies are investigated while keeping the exact stator structure and windings of the reference motor. A comprehensive comparison of the IPM rotor topologies is performed, and the benefits and drawbacks of the designs are highlighted. The best performance design is selected and manufactured for experimental studies. No-load and on-load tests are performed by a motor test system, and the obtained results are compared with the finite element analysis (FEA) results. It is observed that the results are in good agreement. It is shown that it is possible to have an optimized IPM motor for such high speed spindle application by using same stator and winding structure with reference SPM motor