| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect an electrical angle of a rotator of a motor which rotates at a low speed.SOLUTION: An electrical angle estimation device sets an estimation angle sequentially and plots points specified with the estimation angle and a value of d-axis current which is obtained according to the set estimation angle. Next, the electrical angle estimation device selects a point which satisfies predetermined conditions from the plotted points. Then, the electrical angle estimation device calculates a center-of-gravity value of the estimation angle for the selected point as the estimation angle. Thereby, an electrical angle of the rotator which constitutes a motor 90 can be accurately detected, even when the motor 90 rotates at a low speed or stops. |
