Thermal Investigation Of50kW Biaxial Extension Permanent Magnet Synchronous Motor

The capacity of electric propulsion system is increasing with the developingpower electronics, and the permanent magnet synchronous motor(PMSM), whichwith the advantages that the traditional motor cannot compare, is widely applied inthe electric system of ship. However, duo to the special operating environment, thePMSM is usually operating under frequency control, therefore, the eddy currentlosses in permanent magnet and the iron losses would increase significantly, whichcauses high temperature in the PMSM that have effect on the stability and life span,especially permanent magnet. Thus, the optimization of ventilation structure ofPMSM that applied in ships, on the basis of research of fluid flow and thermalcharacteristics of components in the PMSM, is undertaking.In this dissertation, a50kW surface PMSM is studied. Firstly, based on thecomputational fluid dynamics and numerical heat transfer, the three-dimensionsmodel, which fluid flow coupled with thermal transfer used liquid-solid conjugateheat transfer approach, is set up and solved. The fluid flow characteristics and theheat transfer coefficients of surface of main components are analysis, what’s more,the temperature rise distribution and power generation working conditions arecomparative analysis. the correctness is verified by the temperature test. Thus, thestarting temperature of PMSM is analysis based on the finite elements method andfinite volume method and the results are verified by the date of3-D model. Finally,the optimal ventilation structure is seeking by analysis sensitivity factor to thetemperature.