Speed improvements for the optimization of electrical machines — A survey

This article deals with accelerating typical optimization scenarios for electrical machine designs. Besides the advantage of a reduced computation time, this leads to a reduction in computational power and thus to a lower power consumption when running the optimization. If high power density is required, usually highly-utilized electrical machines which feature nonlinear characteristics are applied. As a consequence, typically optimization scenarios are considered where the evaluation of a potential design requires computationally expensive nonlinear finite element (FE) simulations. It is obvious that improving the speed of optimization runs takes top priority and various measures can be considered. This article is about (i) basic easily achievable measures, (ii) techniques for an efficient exploration of the design space, and (iii) advanced strategies to reduce the simulation time, e.g., (a) sophisticated emerging techniques for modeling machine characteristics by paring the number of required FE simulations down to the minimum and (b) nonlinear modeling of the targets of the optimization scenario as functions of the design parameters to further reduce the number of FE evaluations. By way of illustration, the analysis of a typical optimization task is given and achievable speed improvements as well as still present bottlenecks are discussed.