Temperature Field Of Marine High Power Density Permanent Magnet Generator

As the ship power system generating equipment, marine high powerdensity permanent magnet generator has a smaller size, less quality, andhigher power density. Cooling is one of the main difficulties currentlyaffecting the long-term stable and reliable operation of high power densitypermanent magnet motor. The predicted accurate temperature distributionin high power density motor design period can play a positive role to guidethe thermal design.From the accurate calculation of high power density permanentmagnet motor temperature field perspective, based on the flow field–temperature field coupled numerical calculation theory, with the help ofcommercial computing fluid dynamics (CFD) analysis software Fluent,flow-thermal coupled fields of three rated high power density motor arecalculated to meet the engineering calculation accuracy.First, the flow-thermal coupled field of stator outer water-cooledpermanent magnet motor used in vehicles is calculated to obtain theoverall temperature field distribution. The power density of this motor is0.9kW/kg. Then take the temperature field calculation data and measureddata obtained by the prototype temperature rise test for comparison, themaximum error is calculated to meet the engineering calculatingrequirements, which has verified the correctness of the prototype modeland equivalent methods.Second, based on the proven prototype heat-flow coupled fieldmodel and equivalent method, the coupled flow field-temperature field ofa marine high power density permanent magnet generator is calculated.The power density is1.27kW/kg. Its cooling structure contains external water jacket of the stator, wind sleeve and shaft axial flow fan. Duringcalculating the flow-thermal coupled field of water jacket and motor body,the outer surface of stator is equivalent to be a convection face in order toget the equivalent cooling effect of the water jacket. The temperaturedistributions of water jacket and motor body are obtained. And theinfluence of cooling water flow is analyzed.Finally, based on the proven prototype heat-flow model andimproved coupling field equivalent method, the coupled flow-thermalfield of air-water-cooled high power density permanent magnet generatorsfor marine is calculated. For a given axial cooling air flow and ventilationcooling system, the calculating results of the flow and temperature fieldsindicate that the effective utilization of the cooling air flow is greatlyimproved. Improved equivalent model can effectively simulate the flow ofair near the stator winding end region, and improve the stator temperaturefield calculation accuracy. The temperature distributions of various parts ofthe motor are obtained through flow field-temperature field calculationresults.