Approximate analysis of transient heat conduction in the rotor of an induction motor during star-delta starting

In this paper a two-dimensional transient thermal model of the rotor of an induction motor during star-delta starting is presented using finite element formulation and arch-shaped elements. Excepting for providing a more accurate representation of the problem, the proposed model can also reduce computing costs. A temperature-time method is employed to evaluate the distribution of loss in various parts of the machine. Using these loss distributions as an input for finite element analysis, more accurate temperature distributions can be obtained. The model is applied to one squirrel cage Totally Enclosed Fan Cooled (TEFC) Machine of 7.5 kW. The temperature distribution has been determined considering convection from the surface and the end.