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:
Jun. 16, 2005
Hannu Saren, Lappeenranta, FI;
Hannu Saren, Lappeenranta, FI;
Vacon OYJ, Vaasa, FI;
Abstract
A modulation method for a pulse width modulator in the inverter section () of a frequency converter provided with a voltage intermediate circuit, said frequency converter comprising a single-phase mains bridge () to be connected to a single-phase alternating current source (U, N), a direct-voltage intermediate circuit and a controlled load bridge () for feeding a three-phase alternating voltage (U, U, U) of varying frequency and amplitude into a load (), for controlling the semiconductor switches of the inverter section, in which low-capacitance direct-voltage intermediate circuit the waveform of the intermediate-circuit voltage in a normal load situation follows the absolute value of the supply network voltage, and wherein the modulation is implemented using an estimate value of the intermediate-circuit voltage to control the semiconductor switches of the inverter section.