Performance evaluation of axially-laminated anisotropic (ALA) rotor reluctance synchronous motors

Axially laminated anisotropic (ALA) rotor reluctance synchronous motors (RSMs) for use in variable speed drives, have a very high ratio of L_d/L_q and high L_d-L_q values, and do not carry rotor current. Consequently, an ALA rotor RSM has a high torque density, power factor, and efficiency, and its vector control is fairly simple. This paper presents an approach to the performance analysis of RSM and the test results on a prototype ALA-rotor RSM. The theory is based on the machine parameter determination by field computation via analytical and finite element methods. Design criteria derived from theoretical analysis and the nature of the magnetic field obtained from finite element analysis for the ALA-rotor RSM are presented. Test results on a prototype are presented to validate the theoretical calculations and to demonstrate the high performance of the ALA-rotor RSM. The high L_d/L_q ratio of 16 under rated magnetic saturation conditions, high power factor of 0.91, and above 84% efficiency are obtained for a 2-pole, 2 HP laboratory ALA-rotor RSM