| 摘要 |
PROBLEM TO BE SOLVED: To improve the linearity of a motor rotating speed with respect to a set duty.SOLUTION: In a motor control device designed such that an electrification mode in which a switching element applies a pulse voltage corresponding to a PWM signal to the two phases of a three-phase brushless motor, if the set duty DT of the PWM signal is smaller than a first predetermined value (Dmin), the main period duty Dfor a PWM signal applied to a switching element connected to one of the two phases is limited to Dmin as a period for detecting a pulse induction voltage. An adjustment period duty Dfor a PWM signal applied to a switching element connected to the other of the two phases is adjusted so that an average duty Dav=(D+D)/2 is equal to a set duty Dt. If the set duty Dt is smaller than a second predetermined value (Dmin/2), the main period duty Dis corrected by increasing by an amount α of correction in order to offset a decreased amount α of the adjustment period duty Dresulting from setting a dead time period. |
