1. University of Zielona Góra, University of Twente, Hitachi Energy,Zielona Góra,Poland
2. Aalborg University,Department of Energy,Aalborg,Denmark
3. University of Zielona Góra,Institute of Automatic Control, Electronics and Electrical Engineering,Zielona Góra,Poland
4. Politecnico di Milano,Dipartimento di Elettronica, Informazione e Bioingegneria,Milan,Italy