Motor control device controlling synchronous motor
First Claim
1. A motor control device that generates a q-axis current command and a d-axis current command, and uses the commands to control a synchronous motor having saliency, the motor control device comprising:
- a calculating unit calculating a speed reference value that takes an initial value when a torque command is zero, and that decreases as the torque command increases;
a determining unit determining a magnitude relation between a speed command and the speed reference value calculated for the torque command by the calculating unit;
a q-axis-current commanding unit thatgenerates, when the determining unit determines that the speed command is smaller than the speed reference value, the q-axis current command of commanding a q-axis current to flow to the synchronous motor, on the basis ofthe torque command, andan inverse number of a torque constant of the synchronous motor, andgenerates, when the determining unit determines that the speed command is equal to or larger than the speed reference value, the q-axis current command of commanding the q-axis current to flow to the synchronous motor, on the basis ofa function of which an independent variable is the speed command,the torque command, andthe inverse number of the torque constant of the synchronous motor;
a d-axis-current commanding unit generating the d-axis current command of commanding a d-axis current to flow to the synchronous motor, on the basis of the q-axis current command generated by the q-axis-current commanding unit; and
an inverter configured to supply power to the synchronous motor in accordance with the q-axis-current command and the d-axis-current command,whereinthe speed reference value is ω
n,the initial value of the speed reference value when the torque command is zero is ω
0,a change ratio of the speed reference value is k,the torque command is TCMD, andthe calculating unit calculates the speed reference value ω
n on the basis of the equation;
ω
n=ω
0−
k×
TCMD.
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Accused Products
Abstract
A motor control device includes: a calculating unit for calculating a speed reference value that decreases as a torque command increases; a determining unit for determining a magnitude relationship between a speed command and a speed reference value calculated for a torque command by the calculating unit; a q-axis-current commanding unit for generating a q-axis current command on the basis of a torque command and an inverse number of a torque constant of the synchronous motor when a speed command is smaller than a speed reference value, and generating the q-axis current command on the basis of a function of which independent variable is a speed command, the torque command, the inverse number of the torque constant, and when a speed command is equal to or larger than a speed reference value; and a d-axis-current commanding unit generating a d-axis current command, on the basis of a q-axis current command.
5 Citations
3 Claims
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1. A motor control device that generates a q-axis current command and a d-axis current command, and uses the commands to control a synchronous motor having saliency, the motor control device comprising:
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a calculating unit calculating a speed reference value that takes an initial value when a torque command is zero, and that decreases as the torque command increases; a determining unit determining a magnitude relation between a speed command and the speed reference value calculated for the torque command by the calculating unit; a q-axis-current commanding unit that generates, when the determining unit determines that the speed command is smaller than the speed reference value, the q-axis current command of commanding a q-axis current to flow to the synchronous motor, on the basis of the torque command, and an inverse number of a torque constant of the synchronous motor, and generates, when the determining unit determines that the speed command is equal to or larger than the speed reference value, the q-axis current command of commanding the q-axis current to flow to the synchronous motor, on the basis of a function of which an independent variable is the speed command, the torque command, and the inverse number of the torque constant of the synchronous motor; a d-axis-current commanding unit generating the d-axis current command of commanding a d-axis current to flow to the synchronous motor, on the basis of the q-axis current command generated by the q-axis-current commanding unit; and an inverter configured to supply power to the synchronous motor in accordance with the q-axis-current command and the d-axis-current command, wherein the speed reference value is ω
n,the initial value of the speed reference value when the torque command is zero is ω
0,a change ratio of the speed reference value is k, the torque command is TCMD, and the calculating unit calculates the speed reference value ω
n on the basis of the equation;
ω
n=ω
0−
k×
TCMD. - View Dependent Claims (2, 3)
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Specification
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- Resources
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Current AssigneeFanuc Corporation
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Original AssigneeFanuc Corporation
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InventorsUematsu, Hidetoshi
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Primary Examiner(s)Carrasquillo, Jorge L
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Application NumberUS14/609,494Publication NumberTime in Patent Office585 DaysField of Search318/400.02US Class Current1/1CPC Class CodesH02P 21/22 Current control, e.g. using...
