A Comprehensive Study of Thermal and Performance Characteristics in Revamped Multiphase Synchronous Reluctance Machines

This article presents a comprehensive thermal analysis of a three-phase synchronous reluctance motor (SynRM) that has been converted into a five-phase machine using an innovative rewinding approach, providing a practical and cost-effective solution that eliminates the need for a new stator. The thermal behavior is carefully evaluated at both steady-state and transient scenarios, including rated and overload scenarios. The results reveal that the five-phase SynRM has just a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1~^{\circ }$ </tex-math></inline-formula>C temperature rise at specifics spots, retaining thermal performance similar to the original three-phase design. In addition to thermal studies, the rewound machine shows significant improvements in electromagnetic performance. The five-phase machine increases the average torque by 6.56% and reduces the torque ripple by 17.13% compared to the three-phase machine. Efficiency also improves slightly by 0.3% under rated conditions. Under fault situations, the five-phase machine provides 78% of the rated torque, compared to 43% for the three-phase arrangement. Furthermore, this article investigates various slot/pole combinations of standard three-phase stators that can be adequately rewound to produce balanced five-phase winding, as well as the applicability of this rewinding approach to different machine types such as SynRMs and induction motors. Lastly, experimental validation supports these simulation results.