Rotor Design and Optimization of the Three-phase Line-start Synchronous Reluctance Motor

Three-phase line-start synchronous reluctance motor (LS-SynRM) combines the structural features of three-phase squirrel cage induction motor (SCIM) and synchronous reluctance motor, it can start up by asynchronous torque from the rotor conductor bars, it can running by reluctance torque due to the flux barriers in synchronization. Firstly, this paper briefly introduces the mathematical model and starting characteristics of LS-SynRM, Then, the rotor structure of the LS-SynRM is optimized. The influence of the number of rotor barrier layers and the proportion of the flux barriers on the dq-axis inductance of the LS-SynRM is simulated; an optimal rotor flux barriers structure is obtained by finite element analysis (FEA). On this basis, the influence of rotor squirrel cage conductor bars distribution on the starting ability of LS-SynRM is studied and the rotor structure is determined. The simulated rated efficiency of the optimized LS-SynRM model is improved by 2.4% compared with the same frame number IE3 three-phase squirrel cage induction motor (SCIM). Finally, the performance of the optimized LS-SynRM is verified by the prototype test.