Estimating the short-circuit impedance

Arne Hejde Nielsen, Knud Ole Helgesen Pedersen, Niels Kjølstad Poulsen

    Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review


    A method for establishing a complex value of the short-circuit impedance from naturally occurring variations in voltage and current is discussed. It is the symmetrical three phase impedance at the fundamental grid frequency there is looked for. The positive sequence components in voltage and current are derived each period, and the short-circuit impedance is estimated from variations in these components created by load changes in the grid. Due to the noisy and dynamic grid with high harmonic distortion it is necessary to threat the calculated values statistical. This is done recursively through a RLS-algorithm. The algorithms have been tested and implemented on a PC at a 132 kV substation supplying a rolling mill. Knowing the short-circuit impedance gives the rolling mill an opportunity to adjust the arc furnace operation to keep flicker below a certain level. Therefore, the PC performs a simultaneously measurement of impedance and flicker.
    Original languageEnglish
    Title of host publication32'nd Universities Power Engineering Conference, UPEC'97
    Place of PublicationManchester
    Publication date1997
    Publication statusPublished - 1997
    Event32'nd Universities Power Engineering Conference, UPEC'97 - Manchester
    Duration: 1 Jan 1997 → …


    Conference32'nd Universities Power Engineering Conference, UPEC'97
    Period01/01/1997 → …


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