| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a driving method of a brushless DC motor by which the brushless DC motor without a rotation position detecting means directly connected to a motor asynchronously rotating is drawn into a synchronous operation while it is rotating without stopping rotation. <P>SOLUTION: The brushless DC motor 14 asynchronously rotating is changed into a deenergized state by an arithmetic unit 3A and a drive circuit portion 4 with all groups of semiconductor switching devices 2 turned off, then initial both-shaft output voltages Eq1, Ed1 and an initial output frequency to the brushless DC motor 14 are calculated from d(Iq)/dt, d(Id)/dt of a set motor current, Eo, P, R, Lq and Ld of the motor, and a detected rotor speed and a rotor phase of the brushless DC motor 14, using the arithmetic unit 3A, and these are output to the brushless DC motor 14 only at an interval of starting time t<SB>0</SB>. After a lapse of the starting time t<SB>0</SB>, effective values of the output voltages are changed by the arithmetic unit 3A, and the output frequency is also changed into a synchronizing frequency, by which the brushless DC motor 14 is drawn into a synchronous operation while it is rotating. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
