TRANSIENT TEMPERATURE FIELD IN ACTIVE THRUST MAGNETIC BEARING

A transient temperature field model in a thrust magnetic bearing is built in which the heat resources come mainly from the eddy-current loss of solid cores and the copper loss of coils.The transient temperature field,system temperature rise and the thermo-equilibrium state during the rotor starting-up are calculated considering only the copper loss and the eddy-current loss.The numerical results indicate that the temperatures in coils and in magnets rise rapidly,their thermo-equilibrium states are formed within a short time.The temperatures in a thrust-disk and in a rotor rise slowly,their thermo-equilibrium states are formed after a long period time.The temperatures of the thrust-disk and the rotor are far higher than the temperatures of coils and/or magnets after the thermo-equilibrium state has come into being.