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. 20, 2010
Filed:
Jan. 11, 2008
Antti Piippo, Espoo, FI;
Antti Piippo, Espoo, FI;
ABB Oy, Helsinki, FI;
Abstract
A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine, when the permanent magnet synchronous machine is fed with a frequency converter, the method comprising the steps of forming a stator voltage reference for the permanent magnet synchronous machine, injecting a high frequency signal (u) into the stator voltage reference, measuring a DC-link current (i) of the frequency converter when the permanent magnet synchronous machine () is fed with a voltage (u) corresponding to a sum of the stator voltage reference and the injected signal, calculating a stator current estimate (î), calculating a current error (ĩ) as a difference between the stator current estimate and the measured DC-link current, and estimating a rotor speed ({circumflex over (ω)}) and position ({circumflex over (θ)}) of the permanent synchronous machine based on the current error. The injected high frequency signal (u) comprises a direct axis component and a quadrature axis component, the direct axis component having a first frequency and the quadrature axis component having a second frequency, the first and second frequencies being different.