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:
Jun. 22, 1999
Filed:
Jan. 23, 1998
Yuusuke Takamoto, Hitachi, JP;
Ryoso Masaki, Hitachi, JP;
Hiroshi Katada, Hitachinaka, JP;
Sanshiro Obara, Toukai-mura, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A permanent magnet synchronous motor controller includes an inverter for supplying an alternating current power converted from a direct current power to a three-phase permanent magnet synchronous motor, having a pair of switching elements for each of said three phases of the motor; a smoothing capacitor for smoothing the direct current power connected to the inverter in parallel; and a control unit for controlling the motor by ON-OFF controlling each of the switching elements of the inverter, which further including a short circuit transition processing portion for changing control to 3-phase short circuit after performing precursory ON-OFF control of each of the switching elements so as to avoid occurrence of over current at an initial period of performing the 3-phase short circuit while the motor is being rotated.