Abstract: A compressor control method of controlling the vibration amplitude of a compressor equipped with a motor by using the motor is provided. The compressor is driven by the motor, and this method includes controlling, in a specific operating area, the vibration amplitude of the compressor such that the vibration amplitude is substantially constant regardless of changes in the load imposed on the motor and in the number of revolutions of the motor per unit time.

Abstract: A compressor control method of controlling the vibration amplitude of a compressor equipped with a motor by using the motor is provided. The compressor is driven by the motor, and this method includes controlling, in a specific operating area, the vibration amplitude of the compressor such that the vibration amplitude is substantially constant regardless of changes in the load imposed on the motor and in the number of revolutions of the motor per unit time.

Abstract: A power converter converts a DC voltage including a pulsation component into an AC voltage and outputs the AC voltage to a synchronous electrical motor. A control device for controlling the power converter includes a pulsation component detection unit and a control circuit. The pulsation component detection unit detects a pulsation component. The control circuit controls the power converter so that a load angle of the synchronous electrical motor is increased in accordance with increase in an instantaneous value of the pulsation component.

Abstract: A locus of integrals, in terms of time, of unit voltage vectors forms a loop within a period shorter than a reciprocal of a maximum value of an operating frequency, in terms of electrical angle, of a compressor motor, the unit voltage vectors being voltage vectors that are units composing an instantaneous space vector indicating voltage which an inverter for driving the compressor motor outputs except in a dead time period.

Abstract: A locus of integrals, in terms of time, of unit voltage vectors forms a loop within a period shorter than a reciprocal of a maximum value of an operating frequency, in terms of electrical angle, of a compressor motor, the unit voltage vectors being voltage vectors that are units composing an instantaneous space vector indicating voltage which an inverter for driving the compressor motor outputs except in a dead time period.

Abstract: A power converter converts a DC voltage including a pulsation component into an AC voltage and outputs the AC voltage to a synchronous electrical motor. A control device for controlling the power converter includes a pulsation component detection unit and a control circuit. The pulsation component detection unit detects a pulsation component. The control circuit controls the power converter so that a load angle of the synchronous electrical motor is increased in accordance with increase in an instantaneous value of the pulsation component.

Abstract: A subtractor subtracts an angular speed correction amount from a rotational speed command to obtain a corrected rotational speed command. An adder adds a second-axis current correction value to a ?c-axis current to obtain a corrected second-axis current. An angular ripple extraction unit obtains, from a rotational angle on a mechanical angle of a synchronous motor, a rotational angle difference being a ripple component of the rotational angle. An nth-order component extraction unit extracts nth-order components of a fundamental frequency of the rotational angle from the rotational angle difference. A torque conversion unit obtains nth-order components of an estimated value of vibration torque. A correction amount calculation unit obtains the second-axis current correction value using the nth-order components.

Abstract: A subtractor subtracts an angular speed correction amount from a rotational speed command to obtain a corrected rotational speed command. An adder adds a second-axis current correction value to a ?c-axis current to obtain a corrected second-axis current. An angular ripple extraction unit obtains, from a rotational angle on a mechanical angle of a synchronous motor, a rotational angle difference being a ripple component of the rotational angle. An nth-order component extraction unit extracts nth-order components of a fundamental frequency of the rotational angle from the rotational angle difference. A torque conversion unit obtains nth-order components of an estimated value of vibration torque. A correction amount calculation unit obtains the second-axis current correction value using the nth-order components.