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:
May. 25, 2004
Filed:
Mar. 19, 2002
Keijiro Sakai, Kanasagou, JP;
Toshiaki Okuyama, Tokai, JP;
Kinya Nakatsu, Hitachi, JP;
Hiroyuki Tomita, Funabashi, JP;
Junji Kato, Takaishi, JP;
Teiichi Furukawa, Narashino, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Induction voltage command Em* is obtained from inverter's primary frequency command &ohgr; * and torque boost voltage commander produces torque boost voltage command &Dgr;Vz* in accordance with &ohgr; * while integrator produces reference phase command &thgr;d*. uvw/dq converter detects motor excitation current Id (equivalent of no-load current). Next, deviation of excitation current limitation level command Idmax* and detected Id is inputted to limiter processing unit to produce torque boost voltage compensation value &Dgr;Vc for varying &Dgr;Vz* so that Id is smaller than or equal to Idmax*. Inverted &Dgr;Vz* is set up as a lower limiter value of the limiter processing unit. Next, &Dgr;Vc and &Dgr;Vz* are added to produce final compensated torque boost voltage command &Dgr;Vt* and &Dgr;Vt* and Em* are added to produce q-axis voltage command Vq* of the inverter output voltage.