Novel Design Method of Flux-Barrier End Shape of Synchronous Reluctance Motor Based on B-spline Curves

By introducing the widely used B-spline curves, commonly employed in computer graphics, to the rotor topology optimization, this paper presents a novel design method for the flux-barrier end of the synchronous reluctance (SynRel) motor. This novel approach offers enhanced flexibility in shape design along with powerful parametric expression. The flux-barrier end significantly impacts the electromagnetic and stress performance of the rotor, thus playing an important role in the designs for achieving smoother operation, higher efficiency and a more robust structure. Several papers have already proposed some simple but reasonable methods for better flux-barrier shape. This paper illustrates details and performance comparisons between traditional and new designs. Then a SynRel motor with B-spline Curve flux-barrier end is provided with comprehensive improvement in torque, torque ripple, efficiency and stress distribution. Sensitivity analysis is conducted for guidelines of design. Electro-mechanical co-optimization is performed using finite element analysis (FEA), surrogate models, nature-inspired algorithms and multi-level optimization. Additionally, several motors with enhanced performance are presented in the end. In conclusion, the utilization of B-spline curves in the design of flux-barrier ends contribute to achieve greater efficiency in design and performance improvements in terms of torque ripple and stress distribution.