| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect each phase of current supplied to a motor by means of a single current detection element without increasing noise. <P>SOLUTION: A motor control device of an embodiment includes: the current detection element connected to a DC side of an inverter circuit to generate a signal corresponding to a current value; PWM signal generation means for generating a PWM signal pattern according to a carrier signal and a duty; control means for determining whether each of three phases is in a predetermined control period and controlling the phase of the carrier signal or the value of the duty according to the phase corresponding to the control period; and current detection means for detecting a phase current to the motor according to the signal generated by the current detection element and the PWM signal pattern. In view of a minimum waiting time τ from a time of change in the on/off state of at least one switching element of the three phases to the reading of a signal generated at a resistive element, the control means controls either the phase of the carrier signal or the value of the duty to provide a combination of an interval when two phase currents flow simultaneously for the τ time or longer and an interval when at least either of the two phase currents flows individually for the τ time or longer. <P>COPYRIGHT: (C)2012,JPO&INPIT |
