Does transformer inrush challenge future grids? - Laboratory insights

IET conference proceedings., vol. 2023, pp. 2479–2483

Abstract

When switched to an energised grid, transformers produce high inrush currents, which have to be supplied by the grid. In future converter-dominated distribution grids or in islanded microgrids with a reduced short-circuit power, the inrush phenomenon might cause voltage dips and distortions. This paper presents an experimental study characterising the inrush transient at the medium voltage level using real scale hardware. When the setup is fed by a grid-forming converter, the measurements confirm that the voltage quality is impaired during the inrush transient due to current limitation of the converter. In contrast to that, the voltage stays unaffected if the setup is supplied by the public medium voltage grid. Furthermore, the experimental results are statistically evaluated against influencing factors on the inrush transient, such as premagnetisation and transformer loading. The obtained measurement data can be used to parametrise and validate transformer models, which allow to assess the impact of inrush phenomena by dynamic simulations in future research.

Authors 6

1. Alexander Winkens Aachen

   RWTH Aachen University

   Affiliation as printed

   IAEW at RWTH Aachen University, Germany

   IAEW at RWTH Aachen University , Germany

2. Florian Klein-Helmkamp Aachen

   RWTH Aachen University

   Affiliation as printed

   IAEW at RWTH Aachen University, Germany

   IAEW at RWTH Aachen University , Germany

3. Markus Stroot Aachen

   RWTH Aachen University

   Affiliation as printed

   IAEW at RWTH Aachen University, Germany

   IAEW at RWTH Aachen University , Germany

4. Michael Knaak Aachen

   RWTH Aachen University

   Affiliation as printed

   IAEW at RWTH Aachen University, Germany

   IAEW at RWTH Aachen University , Germany

5. Andreas Ulbig Aachen

   RWTH Aachen University

   Affiliation as printed

   IAEW at RWTH Aachen University, Germany

   IAEW at RWTH Aachen University , Germany

6. Tilman Wippenbeck
   Affiliation as printed

   Westnetz GmbH, Germany

   Westnetz GmbH , Germany