| 主权项 |
1. A control device for controlling and driving a three-phase alternate current motor, which has an impressed voltage controlled by an inverter, the control device comprising:
a control phase current acquisition means for acquiring a control phase current sensed value from a control phase current sensor, which is disposed on a control phase as one of three phases of the alternate current motor; a monitor phase current acquisition means for acquiring a monitor phase current sensed value from a monitor phase current sensor, which is disposed on a monitor phase as another one of the three phases different from the control phase; a rotation angle acquisition means for acquiring a rotation angle sensed value from a rotation angle sensor for sensing a rotation angle of the alternate current motor; a current calculation means for calculating a two-phase control current value based on the control phase current sensed value, the monitor phase current sensed value and the rotation angle sensed value; a current estimation means for calculating a one-phase current estimated value for controlling the alternate current motor based on the control phase current sensed value and the rotation angle sensed value in such a manner that the one-phase current estimated value for controlling the alternate current motor is calculated by integrating a correction vector on a d-q axis plane, the correction vector being calculated based on a control phase current basic value and the control phase current sensed value, and the control phase current basic value being a component of the control phase of a previously calculated one-phase current estimated value; a voltage command value calculation means for calculating a voltage command value relating to a voltage to be impressed on the inverter based on the two-phase control current value, which is to be fed back, or the one-phase current estimated value for controlling the alternate current motor, which is to be fed back; an other phase current estimation means for calculating at least one of a monitor phase current estimated value and a control phase current estimated value, the monitor phase current estimated value being estimated based on the control phase current sensed value and the rotation angle sensed value, and the control phase current estimated value being estimated based on the monitor phase current estimated value and the rotation angle sensed value; an abnormality detection means for detecting an abnormality being caused in at least one of the monitor phase current sensor and the control phase current sensor based on at least one of a first comparison result and a second comparison result, the first comparison result being acquired by comparing the monitor phase current estimated value with the monitor phase current sensed value, and the second comparison result being acquired by comparing the control phase current estimated value with the control phase current sensed value; a switching means for switching between a two-phase control mode, in which the voltage command value is calculated based on the two-phase control current value, and a one-phase control mode, in which the voltage command value is calculated based on the one-phase current estimated value for controlling the alternate current motor, and the abnormality detection means detects the abnormality; a number-of-revolutions calculation means for calculating the number of revolutions of the alternate current motor based on the rotation angle sensed value; and a number-of-revolutions determination means for determining whether the number of revolutions is not larger than a predetermined determination value, wherein, when the number of revolutions is not larger than the determination value, the switching means selects the two-phase control mode and wherein, when the number of revolutions is larger than the determination value, the switching means selects the one-phase control mode. |
