Approximate analysis of transient heat conduction in an induction motor during reactor starting

Induction machines transient thermal analysis has been a subject of interest for machine designers in their effort to improve machine reliability. The stator being static is prone to high temperature and the study of transient thermal behaviour in the stator is useful to identify causes of failure in induction machines. The paper presents a two-dimensional transient heat flow in the stator of an induction motor using arch shaped elements in the r-θ plane of the cylindrical co-ordinate system. The model is applied to one squirrel cage TEFC machine of 7.5 kW. Finally the temperatures obtained by this two-dimensional approximation have been compared for different stator currents considering the time required for each stator current during the transient in reactor starting.