Design method for brush permanent magnet DC motors

This paper presents a design methodology for brush PM dc motors. This method integrates several analytical models for the selection of the best structure configuration, and material characteristics. It permits to compute geometrical motor dimensions, according to the application specifications, using non-linear constrained optimization procedure. Collector model and computation of armature equivalent circuit parameters are used to estimate the loss distribution and evaluate several steady state points. This method is validated for two existing commercial dc motors; for drill hand tool and automotive motor fan application. New machine designs using sintered NdFeB permanent magnets are proposed and provide important size and weight reductions without losing performance.