Modeling and estimation of synchronous machine parameters from digitized sudden short-circuit: Armature current

Abstract

This paper presents a novel approach for optimal estimation of the non-saturated parameters of synchronous machines from the digitized samples of the sudden short-circuit armature current. The proposed technique uses the least error squares (LES) parameter estimation algorithm to identify these parameters. The proposed technique splits the armature current into three components, namely; the steady state armature current, transient current, and the subtransient current. The parameters of each component namely; Xd,X'd,T'd,X"dand Td" are determined. After identifying the parameters, the algorithm uses them to determine the digitized samples of the d.c. armature transient current, simply by subtracting the armature current from the armature current using these parameters. These samples are then used to identify the armature time constant Ta as well as the subtransient reactance X"q. The proposed algorithm is tested using simulated data. Effects of the critical parameters on the algorithm are also studied in this paper.