| 摘要 |
Under oscillation-reducing control executed while PWM control is performed, an oscillation-reducing torque (”tr) that is opposite in phase to a varying component of the motor revolution number is generated and, a final torque command value (TR) that is the sum of the oscillation-reducing torque (”tr) and a torque command value (TR0) is used to drive an AC motor (M1). In a transition state where the PWM control mode is switched to overmodulation control mode, the oscillation-reducing torque (”tr) that is determined by multiplying an oscillation-reducing torque (”tr0) by a correction coefficient (Km) that varies depending on a modulation factor gradually decreases as the correction coefficient (Km) decreases and substantially becomes zero when the control mode is switched. Thus, the oscillation-reducing torque (”tr) has no stepped portion that occurs in the oscillation-reducing torque (”tr0) when the control mode is switched. Thus, oscillations in output torque of the AC motor can be reduced. |
