Multiobjective Optimal Design of a High Speed Brushless DC Motor

A multiobjective optimal design of a low-voltage high-speed brushless DC motor is presented. The dedicated motor is modeled in magnetic circuits and designed to meet specifications of a multifunctional optimization scheme, subject to constraints, such as limited space, current density, flux saturation, and driving voltage. Finite element analyses are then carried out to obtain the electromagnetic, thermal, and modal characteristics of the motor for modification and verification of the preliminary design. The motor prototype fabricated is controlled by a PWM driver. The measured motor performance show that the optimal design is reliable and satisfactory and leads to a significant reduction in motor weight, and hence in the machine cost.