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:
May. 24, 2016
Filed:
Mar. 29, 2012
Jussi Tamminen, Helsinki, FI;
Tero Ahonen, Helsinki, FI;
Jero Ahola, Helsinki, FI;
ABB TECHNOLOGY OY, Helsinki, FI;
Abstract
Exemplary methods and systems of determining stall of a fan are disclosed, when the fan is controlled with a frequency converter. The method includes estimating a rotational speed (n) and the torque (T) of the fan. Transferring characteristic curves of the fan to the estimated rotational speed (n) of the fan, determining the stall region of the fan. Determining an operation point of the fan from the estimated rotational speed (n) and estimated torque (T) using the characteristic curves. Calculating RMS values of the low frequency components of the torque and rotational speed estimates (T, n) to obtain a low frequency parameter (S), and determining an occurrence of stall based on at least one of the operation point and the low frequency parameter (S).