Optimum Design of Out-runner PM BLDC Motor with High Torque Density for Flywheel Applications as Energy Storages: Design, FEA and Fabrication

Optimum design of electrical motors may be considered as a complex optimization problem due to the wide variety of mechanical, electrical, electromagnetics parameters, although recently it can be accomplished utilizing heuristic optimization algorithms. In this paper optimum design of an out-runner PM BLDC motor for flywheel energy storage applications is performed. The optimization utilized particle swarm optimization (PSO) algorithm to achieve maximum torque density. Accordingly, the motor design equations are employed in the fitness function of the algorithm. Based on the random initial values and respecting the designs constraints, the optimum design is achieved. Effectiveness of the algorithm results are verified by finite element analysis (FEA) and motor operating parameters are obtained and analyzed. Finally, the prototype of the motor is fabricated and experimental results are demonstrated to show the applicability of the model and analysis.