| CPC H02P 27/085 (2013.01) [H02P 23/14 (2013.01); H02P 25/026 (2013.01)] | 7 Claims |

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1. An inverter control device that controls an inverter to rotationally drive a motor by generating a PWM pulse signal for driving a plurality of switching elements included in the inverter by pulse width modulation and outputting the PWM pulse signal to the inverter, wherein
the inverter control device performs the pulse width modulation by selecting one of a synchronous pulse control mode in which a frequency of a carrier wave used in the pulse width modulation is changed in accordance with a rotation speed of the motor and an asynchronous pulse control mode in which the frequency of the carrier wave is constant regardless of the rotation speed of the motor, and
at a time of switching from the asynchronous pulse control mode to the synchronous pulse control mode, the inverter control device changes a carrier reference phase that is a reference value of a phase of the carrier wave to a different value before and after the switching.
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