Transient Thermal Lumped Parameter Model of an Electrical Excited Synchronous Machine with Forced Air Cooling for Shape optimization

This paper shows the thermal analysis of an electrical excited synchronous machine. For this purpose, a detailed lumped parameter model with transient calculation was built. The machine is cooled with a forced air stream which flows axial through the machine. In this regions the airflow contacts the windings and electrical sheets of the rotor and stator. The model contains regions of the airflow, the electrical sheets and windings of rotor and stator. The modeled heat sources are the iron and ohmic losses. The thermal model was compared with a warming up and cooling down cycle of a experimental setup and shows a good approximation with the measurement. Only the implemented correction parameter for the transition of thermal energy between iron and air are conspicuous low.