Abstract: A motor control device includes a PWM control unit, a carrier frequency setting unit, and a carrier frequency switching calculation unit. The PWM unite generates a signal to drive an inverter by pulse width modulation. The carrier frequency setting unit sets a carrier frequency used for pulse width modulation according to a number of rotations of a motor. The carrier frequency switching calculation unit calculates a frequency switching speed of the carrier frequency and is configured to perform a calculation method. The calculation method includes setting at least one of an emergency mode, a response priority mode, or a fluctuation suppression priority mode in response to various operating conditions.

Abstract: A random value integration unit 175 outputs a random value output from a random value generation unit 174 in a diffusion width Rand output from a diffusion width generation unit 173 by a product of an output of the random value generation unit 174 and an output of the diffusion width generation unit 173. A triangular wave signal generation unit 176 generates a triangular wave signal corresponding to a second carrier frequency fc2 which is obtained by adding the random value output from the random value integration unit 175 to a first carrier frequency fc1 which is an output of a carrier frequency setting unit 171. That is, a frequency obtained by increasing the diffusion width of the first carrier frequency fc1 is used as the second carrier frequency fc2, and the second carrier frequency is used as the carrier frequency.

Abstract: In Steps S54 to S55, when a change rate ??* of a torque command value to a motor 10 is equal to or greater than a predetermined value, a frequency switching speed ?fc of a carrier frequency fc is set based on the number of rotations N of the motor 10 so that a response frequency ?fc of a frequency switching speed ?fc of the carrier frequency fc becomes faster than a response frequency ?ACR of a current control unit 70. In Steps S54 and S56, when the change rate ??* of the torque command value to the motor 10 is less than a predetermined value, the frequency switching speed ?fc of the carrier frequency fc is set based on a torque command value ?* to the motor 10 and the number of rotations N of the motor 10 regardless of the response frequency ?ACR of the current control unit 70.

Abstract: A random value integration unit 175 outputs a random value output from a random value generation unit 174 in a diffusion width Rand output from a diffusion width generation unit 173 by a product of an output of the random value generation unit 174 and an output of the diffusion width generation unit 173. A triangular wave signal generation unit 176 generates a triangular wave signal corresponding to a second carrier frequency fc2 which is obtained by adding the random value output from the random value integration unit 175 to a first carrier frequency fc1 which is an output of a carrier frequency setting unit 171. That is, a frequency obtained by increasing the diffusion width of the first carrier frequency fc1 is used as the second carrier frequency fc2, and the second carrier frequency is used as the carrier frequency.

Abstract: In a motor drive device 120, a phase compensation amount calculation unit 110 calculates a phase compensation amount ?? for compensating a voltage phase ?v* when a control mode is switched in a control selection unit 90. The control selection unit 90 outputs the three-phase voltage command Vuvw* according to any one of the plurality of control modes based on the modulation factor Kh*, the voltage phase ?v*, and the phase compensation amount ??. A PWM control unit 100 outputs gate signals Gun, Gup, Gvn, Gvp, Gwn, and Gwv based on the three-phase voltage command Vuvw* and a rotor position ?d. The inverter 20 has a plurality of switching elements, and controls the plurality of switching elements based on gate signals Gun, Gup, Gvn, Gyp, Gwn, and Gwv to drive the AC motor 10.

Abstract: In a motor drive device 120, a phase compensation amount calculation unit 110 calculates a phase compensation amount ?? for compensating a voltage phase ?v* when a control mode is switched in a control selection unit 90. The control selection unit 90 outputs the three-phase voltage command Vuvw* according to any one of the plurality of control modes based on the modulation factor Kh*, the voltage phase ?v*, and the phase compensation amount ??. A PWM control unit 100 outputs gate signals Gun, Gup, Gvn, Gvp, Gwn, and Gwv based on the three-phase voltage command Vuvw* and a rotor position ?d. The inverter 20 has a plurality of switching elements, and controls the plurality of switching elements based on gate signals Gun, Gup, Gvn, Gyp, Gwn, and Gwv to drive the AC motor 10.

Abstract: An object of the present invention is to reduce output voltage errors of an inverter circuit and stably control a motor until the motor reaches high speed rotation. An inverter device includes a PWM controller that generates a PWM pulse for converting DC voltage to AC voltage in accordance with an output request of a motor, and an inverter circuit that converts the DC voltage to the AC voltage with the PWM pulse generated by the PWM controller and drives a motor. The PWM controller changes the pulse width of the PWM pulse at predetermined timing on the upper side of the trapezoidal wave when the trapezoidal wave modulation using the trapezoidal wave is performed in the overmodulation region.

Abstract: An object of the present invention is to reduce output voltage errors of an inverter circuit and stably control a motor until the motor reaches high speed rotation. An inverter device includes a PWM controller that generates a PWM pulse for converting DC voltage to AC voltage in accordance with an output request of a motor, and an inverter circuit that converts the DC voltage to the AC voltage with the PWM pulse generated by the PWM controller and drives a motor. The PWM controller changes the pulse width of the PWM pulse at predetermined timing on the upper side of the trapezoidal wave when the trapezoidal wave modulation using the trapezoidal wave is performed in the overmodulation region.