Cooling system design and thermal analysis of dual mechanical port machine considering thermal contacts

For smaller and more reliable dual mechanical port (DMP) machine in wind power generation system, there is a need for thermal analysis in the design stage. In this paper, the thermal analysis considering thermal contacts and the cooling system design for a DMP prototype machine are investigated. Some basic knowledge of the heat transfer used in electrical machines and the flow distribution in cooling ducts of the forced-air cooling system are introduced. Considering two typical thermal contacts, finite-element analysis (FEA) of the thermal field is investigated to obtain the detailed temperature distribution. Then, initial design of the cooling system commonly used in electrical machines is tested in the thermal analysis. Finally, a 20 kW DMP prototype machine with the improved wholly forced-air cooling system which can survive with 160% rated load is designed.