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:
Nov. 23, 1999
Filed:
Feb. 28, 1997
Ryoso Masaki, Hitachi, JP;
Yuusuke Takamoto, Hitachi, JP;
Satoru Kaneko, Urizura-machi, JP;
Fumio Tajima, Juo-machi, JP;
Hiroshi Katada, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An inverter system providing both an improvement in the voltage utilization factor and a reduction in the switching loss uses a two-phase switching method. In the inverter system, an .alpha.-axis voltage command value; v.sub..alpha.r and a .beta.-axis voltage command value v.sub..beta.r are input to a stop phase selection means. Six sections are judged based on the values v.sub..alpha.r and v.sub..beta.r to select phases for which it is allowable to stop pulse width modulation control in a two-phase switching method. Then, a phase having the largest absolute value of current is selected among the phases for which it is allowable to stop pulse width modulation control using a U-phase current i.sub.u and a V-phase current i.sub.v. This information is a control mode S. Based on these, two-phase switching calculations are performed by a dead-time compensation calculation means and a pulse width modulation generating means. By doing so, the switching loss can be reduced.