The thermal model of the electric machine

U ovom završnom radu cilj je bio opisati i pojasniti mehanizme prijenosa topline kondukcijom, konvekcijom i zračenjem. Poseban naglasak je na prijenosu topline konvekcijom koja može biti prirodna ili prisilna. Zatim su opisane metode toplinske zaštite, toplinske klase izolacije te načini hlađenja električnih strojeva. Na primjeru je pokazan toplinski proračun i Kirchhoffove toplinske sheme za prijelaznu pojavu zagrijavanja stroja. Provedenim mjerenjem određeni su toplinski otpori uslijed prirodne i prisilne konvekcije te zaključujemo da prisilnim strujanjem zraka toplina se bolje odvodi te stroj doseže nižu vrijednost maksimalne nadtemperature zagrijavanja.In this final paper, the aim was to describe and explain the mechanisms of heat transfer by conduction, convection and radiation. Special emphasis is on convection heat transfer, which can be natural or forced. Then, the methods of thermal protection, thermal insulation classes and methods of cooling electrical machines are described. The example shows the thermal calculation and Kirchhoff thermal schemes for the transient phenomenon of machine heating. The performed measurements determined the thermal resistances due to natural and forced convection, and we conclude that the forced airflow dissipates heat better and the machine reaches a lower value of the maximum excess heating temperature