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:
Aug. 19, 2008
Filed:
Jan. 18, 2007
Masataka Sasaki, Hitachi, JP;
Hideki Miyazaki, Hitachi, JP;
Toshiyuki Ajima, Tokai-mura, JP;
Hiroyuki Saito, Hitachinaka, JP;
Masataka Sasaki, Hitachi, JP;
Hideki Miyazaki, Hitachi, JP;
Toshiyuki Ajima, Tokai-mura, JP;
Hiroyuki Saito, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In such a product that torque of a motor is continuously generated when a rotation number of the motor is nearly equal to zero, since an output voltage is kept at a constant value in accordance with a rotation position of the motor, such a condition that currents are concentrated in a specific element are maintained. As a result, a temperature of the specific element is increased, so that there are problems that a temperature fail of an inverter apparatus may readily occur, and thus, lifetimes of elements are lowered. In a power converter of a motor drive apparatus, windings are energizing-controlled in such a manner that only 1 phase of a switching circuit is pulse-width-controlled when the motor is under motor locking condition.