This thesis overviews current cooling methods for large-scale rotational eletric machines
then presents a program written in Mathcad for calculating ventilation and temperature
rise. With a simple fluid dynamic approach, using the Atkinson equation for turbulent
flows, presents a pressure-flow operating point-seeking algorythm for radial-duct
cylindrical rotor machines.
The presented program enumerates sources of losses during operation, and their
distribution for both synchronous and asynchronous machines. Shows a possible heatflow network for steady-state operation and executes an algorythm which generates a
unique heat-flow network depending on machine geometry. Then, using calculated
losses, air flow and the heat flow network, calculates the temperature map of the machine.
Using measurement data provided by CG Electric Systems Hungary Zrt. calculated and
measured results were compared. The comparison showed that air flow calculation did
not give satisfying results, given no measurement feedback for that part. The heat map
calculation provided more precise results.