| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that a position cannot be detected when DC voltage is low, efficiency is deteriorated, and a motor stops in the worst case when capacity of a smoothing capacitor is made small in conventional sensor-less driving. <P>SOLUTION: In the driving method of the brushless DC motor, the position by a position detecting means 20 is estimated and an inverter is operated when the position cannot be detected. A system is synchronized with position detection at every rotation period in addition to position detection at every switching period. Thus, a stable operation where vibration is reduced becomes possible. <P>COPYRIGHT: (C)2008,JPO&INPIT |
