Advancing energy efficiency in electric vehicles: Design and performance analysis of innovative axial-flux PM motor-driven coolant pumps

The Electric Coolant Pump (ECP) represents a critical component within electric vehicles, yet its application is often limited by torque density and heat. Introducing Axial-Flux Permanent Magnet (AFPM) technology into ECPs results in the emergence of Friction Viscous Loss (FVL), which has been largely overlooked in traditional studies, limiting their guidance and potentially leading to misleading conclusions. In response, this study conducts exploration and design of an AFPM Motor-Driven ECP (AFPMECP). Initially, an accurate analytical expression for FVL of the AFPMECP is introduced, laying the groundwork for a comprehensive examination of the parameters significantly impacting FVL, torque density, and torque ripple. A subsequent sensitivity analysis elucidates the interplay between the FVL model and electromagnetic behaviors, guiding the AFPMECP design strategy considering FVL. Furthermore, performance comparisons with conventional ECP highlight the significantly higher output torque or power provided by AFPMECP under identical thermal loads. Finally, experimental validations confirm enhanced performance of AFPMECP, with a significant improvement in torque constant relative to conventional ECPs, alongside superior hydraulic performance. Overall, these findings underscore the advanced performance and potential energy efficiency gains offered by the study and design of novel AFPMECP, contributing a constructive advancement to thermal management systems of electric vehicles.