A mechanically robust rotor with transverse-laminations for a synchronous reluctance machine for traction applications

This paper presents a method to improve the rotor mechanical designs of the synchronous reluctance machine (SynRM) without considerable degradation in machine´s performance. SynRM have been used in industries due to their unique merits such as fast dynamic response, and low cost. However, taking into account the major requirements of traction applications i.e., high torque and power density, low torque ripple, wide speed range, and high speed operation capability, this machine is still under investigation. Since, proper operation at high speed is a major requirement of the traction motor, the unique geometrical structure of the rotor suggests that its mechanical robustness is a challenge. Thus, prior to the final design, the effect of magnetic and rotational forces on the rotor geometry that are the source of fatigue and harmful deformation at critical points such as tangential and radial ribs need to be analyzed. At low speed, high current demand for maximum torque makes the magnetic forces dominant whereas at high speed, the rotational force dominates the others. In this work, the performance of a SynRM equipped with transversally laminated anisotropic (TLA) rotor with different geometries are investigated and compared while the proposed method is used. It is shown that, although the machine´s proper magnetic and mechanical performance is required for an optimal design, these aspects need to be analyzed simultaneously due to their mutual effect.