ABSTRACT This paper presents the design, analytical modelling and experimental validation of a high‐power induction motor for electric vehicle traction, featuring a novel pump‐free hybrid cooling system. The proposed architecture combines a spiral water jacket with gravity‐assisted oil circulation around the rotor end ring, achieving effective heat dissipation without auxiliary pumps or complex delivery devices. To support the design optimisation, a refined subdomain‐based analytical model incorporating a harmonic slip rotor boundary (HSRB) was developed to more accurately predict the air gap flux distribution and equivalent circuit parameters. The analytical results show excellent agreement with FEM simulations and experimental measurements, confirming the suitability of the proposed approach for both thermal and electromagnetic performance assessment. A full‐scale prototype was manufactured and tested on a dynamometer, delivering 195 kW continuous and 235 kW transient power while maintaining winding and rotor temperatures within Class H limits. Benchmarking against a commercial PMSM further highlights the competitive performance and cost‐effectiveness of the proposed solution.
Aslipour et al. (2026) studied this question.