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:
Apr. 01, 2008
Filed:
Feb. 10, 2006
Samuli Heikkilä, Helsinki, FI;
Samuli Heikkilä, Helsinki, FI;
ABB Oy, Helsinki, FI;
Abstract
A method and arrangement for determining the effective time of a voltage pulse of phase voltage generated by a frequency converter provided with an intermediate voltage circuit, the voltage pulses of the phase voltage being generated from the upper and lower voltage levels (U) of the intermediate voltage circuit, the voltage levels showing a difference in potential (U). The method includes generating a first reference voltage (U) and a second reference voltage (U); scaling the phase output voltage by the scaling coefficient (k); comparing the low-pass filtered phase output voltage with the first reference voltage (); detecting a time instant (t) when the low-pass filtered phase output voltage exceeds the first reference voltage (U); comparing the low-pass filtered phase output voltage with the second reference voltage (U); detecting a time instant (t) when the low-pass filtered phase output voltage is lower than the second reference voltage (U); and calculating the effective time of the voltage pulse on the basis of the time between the first and the second time instants and a constant term.