Numerical and experimental analysis of a dual-channel electric motor housing cooling system

Abstract

Thermal performance of a dual-channel water cooling system embedded in an electric motor housing was analyzed using numerical methods and verified experimentally. The cooling system was designed to reduce coolant pressure drops as well as allowed for flexible cooling strategies of temperature-sensitive interior permanent magnet synchronous motor components. The cooling scheme was analyzed against a comparable single-channel cooling scheme and optimal coolant flow rates were determined for all four conditions that were considered. A motor housing embedded with the dual-channel cooling scheme was then fabricated and the thermal responses of permanent magnets in the rotor and the coils in the stator were directly measured in-situ during motor operations. The results agreed well with those of numerical analyses with a maximum difference of 4.2 °C. Overall, the dual-channel scheme provided improved cooling performance with smaller hydraulic loss compared to the single-channel scheme in both transient and steady state operations.