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. 15, 2010
Filed:
Sep. 07, 2007
Günter Schwesig, Erlangen, DE;
Günter Schwesig, Erlangen, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
A method for safely limiting the torque of a frequency-converter-fed three-phase motor operated under field-oriented control (controlled torque) is disclosed. Actual phase current values of the three-phase motor are used to calculate a sum current signal on two channels which is checked for a sum current value of zero. A rotor position angle is determined on the two channels, and torque-forming current components of the two orthogonal field-oriented current components of a stator current space vector are calculated on the two channels as a function of the measured phase currents and the rotor position angle. The three-phase motor is switched on the two channels without applying a torque if the sum value is not equal to zero and/or if the torque-forming current components calculated on the two channels are not equal. This produces a safety function 'safe torque limiting' which can be integrated in commercially available frequency converters.