With the development of power electronics
technology, new permanent magnet materials and the fast computing power of the
DSP (digital signal processor), the applications of brushless DC motor
is growing popularity. Compared with DC motors, Brushless DC motors has
similar high speed performance, it also overcome the commutation spark, low
reliability and other defects that DC motors using mechanical reversing device
caused. Brushless DC motor with the characteristics of small
size, light weight, high efficiency, flexible shape and size, so it is widely
used in servo system,
CNC machine tools, electric vehicles, household appliances and other various
fields, it has become the main direction of modern servo technology.