The direct calculation of global quantities from an FE formulation for the optimization of power frequency electromagnetic devices

This paper discusses an extension of the method of virtual work for the direct calculation of global electromagnetic quantities from the FE formulation for the optimization of power frequency electromagnetic devices. The discussion is focused on force F evaluation. The sensitivity analysis equations for F are deduced in terms of a generic parameter p. This information is particularly important to find the best search direction for deterministic methods. Particular emphasis is paid to 2D magnetostatic problems. The design optimization of an actuator is presented. The results obtained, which are in accordance with the literature, show the applicability of the formulation.