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:
Feb. 25, 2003
Filed:
Jan. 25, 2002
Derek Albert Paice, Palm Harbor, FL (US);
Other;
Abstract
In an 18-pulse converter system a three-phase to nine-phase auto-transformer with multiple windings per phase is used to power a nine-phase AC to DC converter. The transformer kVA rating is about 55% of the DC load kW. The basic topology is that of a wye connection, but an active delta path is added to allow circulation of the third harmonics necessary for proper operation. The design requires substantially fewer coils than other three-phase to nine-phase auto-transformers. The voltage ratio can be selected so as to give an average DC output from an 18-pulse converter which is generally the same as that of a conventional three-phase bridge rectifier without a transformer. However, the topology described is also suitable for step up or step down of voltage as required. Where necessary to further reduce high frequency harmonic currents, a three-phase ac line reactor may be connected in series with the source of ac power.