Rotor-Integrated Self-Cooling of Permanent Magnet Machines: Thermal Modelling, Winding Effects, and Modular Ventilation Design

Permanent magnet (PM) machines are widely used in high power density applications, where effective thermal management is essential for maintaining performance and reliability. This thesis investigates integrated self cooling strategies for PM machines using rotor driven airflow generation and internal ventilation enhancement.
A rotor integrated fan blade structure is proposed for surface mounted permanent magnet (SPM) machines to generate internal airflow without external cooling devices. Three dimensional computational fluid dynamics (CFD) models and experimental tests are conducted to evaluate the effects of rotor design and airflow arrangement on thermal performance.
The influence of different winding topologies, including single layer concentrated winding, double layer concentrated winding, and distributed winding, on self cooling performance is investigated through coupled electromagnetic and CFD analysis. Furthermore, a modular SPM machine concept combining rotor driven self cooling with flux gap ventilation is developed to improve internal airflow management.
Overall, this thesis provides design guidelines for enhancing the thermal performance of high power density PM machines through coordinated electromagnetic, thermal, and airflow design.