Patent ID: 9391552
Filing Date: 2016-07-12
CPC Classification: B60L,H02P,Y02T

Claim Text:
1. A method for establishing a rotor angle of a synchronous machine, said method comprising: determining an initial estimated value of the rotor angle of the synchronous machine; feeding at least one refinement voltage pulse pair, each refinement voltage pulse having a predefined pulse length and pulse height, into the stator of the synchronous machine, wherein the refinement voltage pulse pairs are each fed into the stator at an equal angular distance from the initial estimated value each in different directions from the initial estimated value; detecting angle-dependent refinement current responses to the refinement voltage pulses; determining angle-dependent refinement phase differences on the basis of the respective detected refinement current responses; determining first estimated curves on the basis of at least some of the angle-dependent refinement current responses; determining second estimated curves on the basis of at least some of the angle-dependent refinement phase differences; and determining a refined estimated value of the rotor angle of the synchronous machine on the basis of the first and the second estimated curves.