| 摘要 |
A motor drive control device 1 includes a three-phase rectifier 11; a boosting circuit 13 including a reactor 21, a switching element 23, and a backflow preventing element 27 and boosts a direct-current bus voltage supplied from the three-phase rectifier 11; a smoothing capacitor 15; an inverter circuit 17; a boosting control unit 51; an inverter control unit 53; and a circuit protecting unit 55 suppresses a ripple current flowing through the smoothing capacitor 15. In the circuit protecting unit 55, a correlation of an on-duty ratio of the switching element 23 included in the boosting circuit 13, the output power of the inverter circuit 17, and an estimated ripple current that is an estimate of the ripple current flowing through the smoothing capacitor 15 are set. On the basis of the on-duty ratio of the switching element 23, output power of the inverter circuit 17, and the correlation, the circuit protecting unit 55 determines an estimated ripple current being an estimate of the ripple current flowing through the smoothing capacitor 15. When the estimated ripple current exceeds a preset threshold, the circuit protecting unit 55 suppresses the ripple current. |
