The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 11, 2006
Filed:
Mar. 26, 2004
Kazuaki Tobari, Hitachiota, JP;
Tsunehiro Endou, Hitachiota, JP;
Yoshitaka Iwaji, Hitachinaka, JP;
Hidefumi Shirahama, Hitachi, JP;
Yasuo Notohara, Hitachiota, JP;
Kazuaki Tobari, Hitachiota, JP;
Tsunehiro Endou, Hitachiota, JP;
Yoshitaka Iwaji, Hitachinaka, JP;
Hidefumi Shirahama, Hitachi, JP;
Yasuo Notohara, Hitachiota, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method controls a torque of an a. c. motor which does not cause a shortage of torque by using an economical current detection which estimates d- and q-axis currents Idc, Iqc from d. c. current IDC flowing through an input d. c. bus line of a power converter. A value of d- and q-axis motor currents Id, Iq of a rotational coordinate system are estimated from detected input d. c. current IDC flowing through the bus line of the power converter to which power is input from a d. c. power source. A output voltages of the power converterare controlled so that the estimated currents Idc, Iqc are equal to respective current instruction values Id*, Iq*. Errors of motor constants are determined from information on the motor currents and the rotational phase errors by an operation.