A useful multi-objective optimization design method for PM motors considering nonlinear material properties

A fast and efficient multi-objective optimization design method is developed for the surface mount permanent magnet (SMPM) class of electric machines. An analytical design model of the SMPM machines with considerations of the steel´s nonlinear property is developed and in this analytical model the number of variables to be optimized is reduced to only three. A canonical particle swarm optimization (PSO) method with penalty function for the designs having magnetic saturation is developed to find the optimal solution for a user defined objective function. After several trial solutions with the PSO, the optimal regions for both the design variables and the performance indexes can be estimated. The results will provide useful information for both the drive system designer and the machine designer at an early stage of the design process.