Effect of thermal resistances on value and temperature distribution of electric machines

The paper presents the problem of calculating the dependence of temperature of different parts of electric machines on changes of thermal resistances in the network branches. The method of equivalent thermal networks and the method of thermal coefficients, whose principles are shown in the paper, were used for analysis. The analysis is illustrated by examples of calculation concerning a totally enclosed motor with a ribbed frame. The calculation example serves to illustrate the dependence of temperature on resistances and to compare the effect of change of different resistances on heating of different machine parts.