Motor control apparatus and electric power steering system
AssigneeJtekt Corporation
InventorsTakeshi UEDA, Shigeki NAGASE, Kouya YOSHIDA
Life of this patent
Estimating the term…
Abstract
If the magnitude of a command voltage vector is greater than a predetermined voltage value indicated by a voltage limit circle, the magnitude of a voltage vector, which corresponds to a q-axis current and which forms the command voltage vector, is adjusted so that the magnitude of the command voltage vector is equal to or less than the predetermined voltage value. Then a q-axis current estimated value is obtained based on i) the ratio of the magnitude of the voltage vector from the q-axis current after adjustment to the magnitude of the voltage vector from the q-axis current before adjustment, and ii) a q-axis current command value.
Claims14
A motor control apparatus that drives a brushless motor, comprising:
- a current command value setting portion that sets a d-axis current command value and a q-axis current command value that are indicative of currents to be supplied to the brushless motor;
- a voltage command value calculating portion that calculates a d-axis voltage command value and a q-axis voltage command value that are indicative of voltages to be applied to the brushless motor in order to supply the current indicated by the d-axis current command value and the q-axis current command value to the brushless motor;
- a determining portion that determines whether the magnitude of a command voltage vector, in which the d-axis voltage command value is designated as a d-axis voltage component and the q-axis voltage command value is designated as a q-axis voltage component, is greater than a predetermined voltage value;
- a voltage vector adjusting portion that adjusts the magnitude of a voltage vector that corresponds to a q-axis current and that forms the command voltage vector in order to adjust the magnitude of the command voltage vector being equal to or less than the predetermined voltage value when the determining portion determines the magnitude of the command voltage vector being greater than the predetermined voltage vector value;
- and
- a current estimating portion that estimates a q-axis current estimated value based on i) a ratio of the magnitude of the voltage vector after adjustment to the magnitude of the voltage vector before adjustment, and ii) the q-axis current command value.
A motor control apparatus that drives a brushless motor, comprising:
- a first current command value setting portion that sets a q-axis current command value indicative of a current to be supplied to the brushless motor;
- an angular velocity detecting portion that detects the angular velocity of a rotor of the brushless motor;
- a second current command value setting portion that sets a d-axis current command value indicative of a d-axis current to be supplied to the brushless motor based on at least the q-axis current command value and the angular velocity;
- a voltage command value calculating portion that calculates a d-axis voltage command value and a q-axis voltage command value that are indicative of voltages to be applied to the brushless motor in order to supply the current indicated by the d-axis current command value and the q-axis current command value to the brushless motor;
- a determining portion that determines whether the magnitude of a command voltage vector, in which the d-axis voltage command value is designated as a d-axis voltage component and the q-axis voltage command value is designated as a q-axis voltage component, is greater than a predetermined voltage value;
- a voltage vector adjusting portion that adjusts the magnitude of a voltage vector that corresponds to a d-axis current and that forms the command voltage vector in order to adjust the magnitude of the command voltage vector being equal to or less than the predetermined voltage value when the determining portion determines the magnitude of the command voltage vector being greater than the predetermined voltage vector value;
- and
- a current estimating portion that estimates a d-axis current estimated value based on i) a ratio of the magnitude of the voltage vector after adjustment to the magnitude of the voltage vector before adjustment, and ii) the d-axis current command value.
Dependencies are inferred from the claim text.