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. 20, 1997
Filed:
Apr. 16, 1996
Ryoso Masaki, Hitachi, JP;
Takashi Ikimi, Hitachi, JP;
Hironori Ohashi, Funabashi, JP;
Yuusuke Takamoto, Hitachi, JP;
Seiji Ishida, Funabashi, JP;
Sanshiro Obara, Toukai-mura, JP;
Hitachi, Ltd., , JP;
Abstract
The invention provides an electric power converter system which uses a standard low-priced control processor and is suitable for improving the voltage utilization factor in the output voltage. D-axis and q-axis voltage commands and a rotation angle .theta. defining a voltage command vector on a rotating coordinate system are input to a voltage calculation circuit. The voltage command vector is transformed in a rotating coordinate transformation unit into a .alpha. axis and .beta. axis voltage commands to be defined relative to stationary coordinate system. A judgment unit determines which section contains the voltage command vector, from among three sections on the stationary coordinate system having one axis thereof (.alpha.-axis for example) coinciding with one axis of the three phases. A three phase voltage generation unit then selects a method of calculation on the basis of a result of the section determination, and calculates three phase voltage command values respectively utilizing the .alpha. axis and .beta. axis voltage command values. Since calculation requires only a simple add/subtract and shift operation, a high performance economical power converter system which improves the voltage utilization factor substantially can be realized.