INVERTER VECTOR DRIVING SYSTEM AND METHOD FOR ESTIMATING CAPACITANCE USING THE SAME
First Claim
1. A method for estimating capacitance in an inverter vector driving system including a capacitor to which a rectified DC voltage of a three-phase power supply is charged and a PWM inverter configured to transform the DC voltage into a three-phase AC voltage to be applied to an induction motor (IM), comprising:
- operating the motor in a regeneration mode;
generating a d-axis voltage command using a d-axis current command of a d-q coordinate system for the motor and a d-axis DC current obtained from the motor, and generating a q-axis voltage command using a q-axis current command, a q-axis DC current obtained from the motor, a q-axis current command including a predetermined AC component, and a q-axis AC current obtained from the motor;
adjusting a pulse of the PWM inverter by using the d-axis voltage command and the q-axis voltage command; and
estimating capacitance of the capacitor by using a DC-link voltage and a DC-link current that are generated at the capacitor due to the inclusion of the AC component.
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Accused Products
Abstract
The present invention relates to an inverter vector driving system and a method for estimating capacitance using the same. The present invention provides a method for estimating capacitance in an inverter vector driving system including a capacitor to which a rectified DC voltage of a three-phase power supply is charged, and a PWM inverter configured to transform the DC voltage into a three-phase AC voltage to be applied to a motor of an induction motor, including: operating the motor of the IM in a regeneration mode; generating a d-axis voltage command and a q-axis voltage command for the motor; adjusting a pulse of the PWM inverter by using the d-axis voltage command and the q-axis voltage command; and estimating capacitance of the capacitor by using a DC-link voltage and a DC-link current that are generated at the capacitor due to the inclusion of the AC component.
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Citations
14 Claims
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1. A method for estimating capacitance in an inverter vector driving system including a capacitor to which a rectified DC voltage of a three-phase power supply is charged and a PWM inverter configured to transform the DC voltage into a three-phase AC voltage to be applied to an induction motor (IM), comprising:
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operating the motor in a regeneration mode; generating a d-axis voltage command using a d-axis current command of a d-q coordinate system for the motor and a d-axis DC current obtained from the motor, and generating a q-axis voltage command using a q-axis current command, a q-axis DC current obtained from the motor, a q-axis current command including a predetermined AC component, and a q-axis AC current obtained from the motor; adjusting a pulse of the PWM inverter by using the d-axis voltage command and the q-axis voltage command; and estimating capacitance of the capacitor by using a DC-link voltage and a DC-link current that are generated at the capacitor due to the inclusion of the AC component. - View Dependent Claims (2, 3, 4, 5, 6, 13)
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7. An inverter vector driving system for estimating capacitance comprising:
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a capacitor to which a rectified DC voltage of a three-phase power supply is charged; a PWM inverter configured to transform the DC voltage into a three-phase AC voltage to be applied to a motor of an IM; a calculating unit configured, while the motor is operated in a regeneration mode, to generate a d-axis voltage command using a d-axis current command of a d-q coordinate system for the motor and a d-axis DC current obtained from the motor, and to generate a q-axis voltage command using a q-axis current command, a q-axis DC current obtained from the motor, a q-axis current command including a predetermined AC component, and a q-axis AC current obtained from the motor; a pulse adjusting unit configured to adjust a pulse of the PWM inverter by using the d-axis voltage command and the q-axis voltage command; and an estimating unit configured to estimate capacitance of the capacitor by using a DC-link voltage and a DC-link current which are generated at the capacitor by the inclusion of the AC component. - View Dependent Claims (8, 9, 10, 11, 12, 14)
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Specification