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:
Oct. 19, 2004
Filed:
May. 16, 2003
Jaakko Ollila, Pirkkala, FI;
Risto Komulainen, Klaukkala, FI;
Vacon Oyj, Vaasa, FI;
Abstract
An inverter control unit having a bridge circuit provided with controllable semiconductor switches in upper and lower circuit arms, which bridge circuit converts a direct voltage to be fed to the inverter into an alternating voltage of variable frequency and amplitude, said control unit controlling the semiconductor switches by pulse-width modulation (PWM) to generate an inverter output voltage, and said control unit comprising a first control section ( ) at ground potential and a second control section ( ) at the potential of the semiconductor switches, galvanically isolated channels being provided between said sections for serial transmission of control data from the first control section to the second control section and of feedback data from the second control section to the first control section. A modulation circuit controlling the semiconductor switches is disposed in the second control section ( ) at the potential of the semiconductor switches, and the modulation circuit forms the time integral of the difference between the reference and actual values (U , U ) of the phase voltages of the inverter, compares this difference to positive and negative limits (L , L ) and when the time integral exceeds the positive or the negative limit, drives the phase switch in the upper or lower arm of the phase in question into conduction.