Core Shape Design of Electrical Devices for Iron Loss Reduction

A shape-design method for electromagnetic devices reducing the iron loss is presented. The iron loss of a magnetic system can be reduced by controlling the shape of the flux path. The sensitivity information, i.e., the iron loss variation with respect to the shape variation, is obtained exploiting the finite element discretization. The iron loss depends on flux density distribution and loss data which is provided by the iron manufacturer. This sensitivity method is applied to two numerical examples: a single-phase shell-type transformer and a 3-phase cage induction motor. Since these optimization problems have nonlinear equality constraints, the gradient projection method is employed.