Abstract

For development of electric machines, particularly induction machines, temperature limit is a key factor affecting\nthe efficiency of the overall design, particularly during transient state. Since conventional loading of induction motors is\noften expensive, the estimation of temperature rise by tools of mathematical modeling becomes increasingly important and as\na result of which computational methods are widely used for estimation of temperature rise in electrical machines. This paper\ndescribes the problem of two dimensional transient heat flow in the stator of induction motor during star delta starting. The\nstator being static is prone to high temperature and the study of thermal behavior in the stator is useful to identify the causes\nof failure in induction machines. The temperature distribution is obtained using finite element formulation and employing\narch shaped elements in the r-θ plane of the cylindrical co-ordinate system. This model is applied to one 3-phase slip ring\ninduction motor of 75 kW rating.