Novel High-Performance SynRM Design Method: An Easy Approach for A Complicated Rotor Topology

The complex rotor structure of the synchronous reluctance machine (SynRM) is analyzed in this paper. Three macroscopic design parameters are introduced: insulation ratios in the d- and q-axes and the rotor slot pitch in the d-axis controller angle. These parameters are optimally linked to the microscopic and detailed SynRM rotor geometry (barriers, insulation layer and segments, magnetic layers inside the rotor) parameters (dimensions) by introducing and combining a general rotor arrangement with an analytical explanatory theory. This theory represents the anisotropic behavior of the SynRM rotor structure according to the literature. Based on these parameters, a novel, simple, fast, and systematic design procedure for a SynRM rotor with specific stator structure is developed and presented. A SynRM rotor can be competitively optimized with respect to an induction machine (IM) by a limited number of finite-element-method sensitivity analysis studies of the macroscopic design parameters. The machine torque can be maximized by finding the best insulation ratios, while the torque ripple can be minimized by determining the best rotor slot pitch in the d-axis. Both these optimizations can be defined independently of the stator structure. The method is validated by the design (using this procedure), prototype, and measurement of a specific SynRM machine with three barriers and a stator standard frame size of 160 [International Electrotechnical Commission (IEC)]. A heat-run test was done for both the SynRM and its corresponding IM with the same stator and test bench.