An Optimal Design Framework for Pole-Changing Induction Motors

Permanent magnet&#x2013;less motors are increasingly attracting research interest due to the scarcity and high cost of rare-earth magnet resources. Among them, induction motors, particularly multi-phase induction machines, are gaining attention for their superior fault-tolerant capabilities and higher torque and power density. Pole-changing induction motors (PCIMs), a subclass of multi-phase induction machines, offer enhanced torque performance and an extended constant power speed range (CPSR), both of which are critical for vehicular applications. Despite these advantages, systematic design frameworks for PCIMs tailored to electric vehicle application remain limited in the literature. This paper presents a comprehensive design methodology for PCIMs that incorporates optimization to maximize torque output in both pole modes while simultaneously extending the CPSR, subject to current and voltage constraints. The torque behavior during pole transition is also investigated, with sensitivity analysis emphasizing the influence of inductance selection on transient torque dynamics during pole switching. This work therefore provides a structured and practical approach that incorporates parameter-dependent transient characteristics, enabling improved dynamic performance alongside steady-state optimization. The proposed framework is demonstrated through finite element analysis in ANSYS Maxwell 2D and dynamic simulations in MATLAB<inline-formula> <tex-math notation="LaTeX">$/$ </tex-math></inline-formula>Simulink. Furthermore, a 5-hp prototype PCIM is fabricated and experimentally validated, confirming the practical feasibility and effectiveness of the proposed optimization-based design methodology.