ABSTRACT
Quality factors of motor include high torque and power density, low torque ripple, high efficiency, low noise and vibration, robustness, low cost, etc. It is not easy to meet all of the quality factors, because many of them are incompatible with each other. Motor design is a very complex and time-consuming task, because the designer should consider electro-magnetics, material properties, thermal behavior, noise and vibration, insulation material, motor control issues, limitations of power electronics, etc.
