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:
Mar. 13, 2007
Filed:
Dec. 14, 2004
Panu Virolainen, Espoo, FI;
Samuli Heikkilá, Helsinki, FI;
Marko Hinkkanen, Kirkkonummi, FI;
ABB Oy, Helsinki, FI;
Abstract
A method for determining output currents of a three-phase frequency converter comprising a voltage intermediate circuit and three power switch pairs constituting an output of the frequency converter, wherein the power switches constituting a pair are coupled in series between a positive and a negative busbar of the voltage intermediate circuit so that a midpoint of each switch pair constitutes a phase output of the frequency converter. The method comprises, during use of the frequency converter, steps of forming a voltage reference vector for the output power switches such that only two switch pairs are modulated during one modulation sequence, controlling said two switch pairs to implement a voltage reference vector during the modulation sequence by using one zero vector, measuring current of the voltage intermediate circuit of the frequency converter at a predetermined moment in the modulation sequence, and changing actively, during use of the frequency converter, the zero vectors to be used in the modulation sequences.