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:
Feb. 21, 2017
Filed:
Dec. 03, 2013
Applicant:
Nidec SR Drives Ltd., Harrogate, North Yorkshire, GB;
Inventor:
Michael James Turner, Whixley, GB;
Assignee:
NIDEC SR DRIVES LTD., Harrogate, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R 27/08 (2006.01); G01R 31/34 (2006.01); G01K 7/16 (2006.01);
U.S. Cl.
CPC ...
G01R 27/08 (2013.01); G01K 7/16 (2013.01); G01R 31/343 (2013.01); G01R 31/346 (2013.01); G01K 2217/00 (2013.01);
Abstract
In an electrical machine which has unidirectional excitation applied to its windings, the mean values of voltage and current can be computed from the instantaneous phase voltage and current by the use of, for example, low-pass filters (in either the analogue or digital domain). The value of winding resistance can then be calculated by dividing the mean voltage by the mean current. This avoids the cost, fragility and potential inaccuracy of conventional temperature sensors, and provides the controller with an ongoing estimate of winding temperature.