1. Technology Center for Energy, University of Applied Science Landshut, Wiesenweg 1, 94099 Ruhstorf a.d. Rott, Germany
2. Heinz-Mayer Leibnitz Zentrum (MLZ), Technical University Munich (TUM), Lichtenbergstraße 1, 85748 Garching, Germany
3. Chair of Electrical Energy Systems, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany