Magnetic field analysis of induction motor for optimal cooling duct design

It is important to understand the leakage flux distributions to get a better design of induction motors. Computer simulation using the finite element method (FEM) is an important tool for achieving this objective. This paper presents a method for calculating the steady-state leakage flux distributions in induction motors. FEM is used here to study the field behavior of an induction motor in terms of magnetic vector potential (MVP), which allows the easy determination of flux and flux density. Because of complexity of the domain, triangular elements, due to their flexibility to fit in any irregular geometry are used. With the help of MVP distribution obtained use of these elements have been made to study the effect of shape of the cooling duct on the rotor laminations of an induction motor. An optimum modified shape of ventilating hole is thus obtained without having any adverse effect on MVP and flux density.