ABSTRACT
New advancements in fast semiconductor switches and cost-effective DSP processors have revolutionized the adjustable speed motor drives. These new opportunities have contributed to novel configurations for electric machines in which the burden is shifted from complicated structures to software and control algorithms. This in turn has resulted in considerable reduction in cost, while improving the performance of the overall drive system. Brushless DC (BLDC) is one example of this trend. Very compact geometry, high efficiency, and a simple control are among the main incentives for satisfying many adjustable speed applications with this emerging technology. Figure 11.1 shows the DC motor and brushless DC motor configurations. The DC motor has mechanical components, such as commutators and brushes, whereas the brushless DC motor replaces the mechanical commutators with electronic switches.
