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:
Mar. 10, 2015
Filed:
Sep. 24, 2010
Heiko Stichweh, Springe, DE;
Albert Einhaus, Garrel, DE;
Matthias Wisgickl, Hirschau, DE;
Lenze Drives GmbH, Extertal, DE;
Abstract
The invention relates to a method for the open-loop or closed-loop control of an asynchronous machine with or without speed feedback, the asynchronous motor being controlled by a control device (converter or servo converter). First of all, a voltage vector rotating at a rotary field frequency is specified and impressed, both the rotary field frequency and the voltage vector being determined by an open-loop or closed-loop control based on a voltage-frequency characteristic curve configured in any manner and the voltage vector being adapted by a cos φ closed-loop control. Desired values of cos φ are calculated using rating plate data and equivalent circuit diagram data for an optimum-loss or loss-optimized operation of the asynchronous machine for the calculation of cos φ, which results in optimized-loss operation. A value for cos φis then determined using the impressed voltage vector and a current vector or using the real power and apparent power. Thereafter, the difference is calculated between cos φand cos φand a cos φ closed-loop control is fed with this input difference. A control value of the controller for cos φ is calculated and restricted and the voltage vector is adapted by the control value of the cos φ closed-loop control.