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:
Jul. 02, 2002
Filed:
Mar. 21, 2001
Gerd Griepentrog, Gutenstetten, DE;
Diethard Runggaldier, Stegaurach, DE;
Siemens AG, Munich, DE;
Abstract
In order to measure the rotation speed of an induction machine whose stator is connected via a controllable AC controller to a single-phase or polyphase AC power supply system, the stator is disconnected from the AC power supply system for at least a predetermined time period (&Dgr;t). This is preferably achieved by opening active devices in the AC controller, with at least one stator voltage, which is induced in the stator by the rotary movement of the rotor, being measured in this time period (&Dgr;t). The measured values are used to determine the frequency of the stator voltage and to derive the rotation speed of the induction machine.