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:
Jun. 01, 2010
Filed:
Nov. 27, 2007
Ari Hyvärinen, Helsinki, FI;
Antti Tarkiainen, Järvenpää, FI;
Johanna Laukkanen, Rajamäki, FI;
ABB Oy, Helsinki, FI;
Abstract
A method for thermal protection of a frequency converter and a frequency converter includes means for controlling the output current of the frequency converter. The method includes the steps of determining predetermined data points which define a thermal current limit for a semiconductor component of the frequency converter at specific temperatures at plural switching frequencies, and determining predetermined data points which define a thermal current limit for the semiconductor component at specific temperatures at a zero converter output frequency. The method also includes determining the highest allowable thermal current as a function of a measured temperature, a determined switching frequency, and a determined output frequency based on the defined data points, and limiting the output current of the frequency converter to the determined highest allowable thermal current.