Patent ID: 8281886

Claim:
An electric motor control device comprising: an inverter that supplies an output of a primary-side DC power supply to an electric motor to control driving of the electric motor; a converter that includes a voltage increasing power supply device that increases a voltage of the primary-side DC power supply to supply the inverter with the increased voltage as a secondary voltage, and a regenerative power supply device that reversely supplies regenerative power from the inverter to the primary-side DC power supply; a secondary-side target voltage determination unit that determines a secondary-side target voltage such that the electric motor is driven on the basis of one of a first region in a modulation mode in which PWM power is applied to at least two phases and in which field weakening control is not performed, a third region in a modulation mode in which PWM power at a voltage lower than a maximum voltage of the converter is applied to at least two phases and in which field weakening control is performed, and a second region in a one-pulse mode in which rectangular-wave power at a voltage lower than the maximum voltage of the converter is applied to all phases and in which field weakening control is performed; a converter control unit that controls the voltage increasing power supply unit and the regenerative power supply unit of the converter such that the secondary voltage becomes the secondary-side target voltage; and an electric motor control unit that controls the inverter on the basis of a target torque and a rotation speed of the electric motor and the secondary voltage such that an output torque of the electric motor becomes the target torque.