Power converter
AssigneeHitachi Industrial Equipment Systems Co., Ltd.
InventorsKazuaki Tobari, Yoshiyuki Taguchi, Yuta Iwase
Life of this patent
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Abstract
A power converter having a control unit that controls the output frequency, output voltage, and output current of the motor, wherein the control unit calculates a first torque current command from a deviation between a speed reference point and a speed estimate of the motor, The control unit switches the control mode to either a control mode that suppresses pulsation of the motor speed or a control mode that suppresses pulsation of the motor torque, and calculates a second torque current command from the first torque current command and the switched control mode.
Claims11
A power converter with a control unit that controls output frequency, output voltage and output current of a motor,
- the control unit calculates a first torque current command from a deviation between a speed reference point and a speed estimate of the motor,
- switches a control mode to either a control mode that suppresses pulsation of a speed of the motor or a control mode that suppresses pulsation of a torque of the motor, and
- calculates a second torque current command from the first torque current command and a switched control mode,
- the control unit equips a first secondary transfer function filter corresponding to a control mode that suppresses the pulsation of the speed of the motor and a second secondary transfer function filter corresponding to a control mode that suppresses the pulsation of the torque of the motor, and
- selects either the first secondary transfer function filter or the second secondary transfer function filter from the speed reference point of the motor.
A power converter with a control unit that controls output frequency, output voltage and output current of a motor,
- the control unit calculates a first torque current command from a deviation between a speed reference point and a speed estimate of the motor,
- switches a control mode to either a control mode that suppresses pulsation of a speed of the motor or a control mode that suppresses pulsation of a torque of the motor, and
- calculates a second torque current command from the first torque current command and a switched control mode,
- the control unit equips a first secondary transfer function filter corresponding to a control mode that suppresses the pulsation of the speed of the motor and a second secondary transfer function filter corresponding to a control mode that suppresses the pulsation of the torque of the motor,
- calculates the power value of the motor, and
- selects either the first or second secondary transfer function filter from the power value of the motor.
A power converter with a control unit that controls output frequency, output voltage and output current of a motor,
- the control unit calculates a first torque current command from a deviation between a speed reference point and a speed estimate of the motor,
- switches a control mode to either a control mode that suppresses pulsation of a speed of the motor or a control mode that suppresses pulsation of a torque of the motor, and
- calculates a second torque current command from the first torque current command and a switched control mode,
- the control unit switches between the control modes by changing the damping ratio parameters set for the secondary transfer function filter,
- the damping ratio parameter comprises a first damping ratio parameter and a second damping ratio parameter power converter,
- the first damping ratio parameter is a coefficient of a linear component of a Laplace operator of a numerator term of the secondary transfer function filter,
- the second damping ratio parameter is a coefficient of a linear component of a Laplace operator of a denominator term of the secondary transfer function filter,
- the control unit change the first and second damping ratio parameters to the damping ratio parameters that suppress the pulsation of the speed of the motor when the control mode that suppresses the pulsation of the speed of the motor is selected,
- change the first and second damping ratio parameters that suppress the pulsation of the torque of the motor when the control mode that suppresses the pulsation of the torque of the motor is selected.
Dependencies are inferred from the claim text.