1. Institute of Electric Power Engineering, Faculty of Environmental Engineering and Energy, Poznan University of Technology, 60-965 Poznan, Poland
2. Institute of Electrical Engineering and Electronics, Faculty of Control, Robotics and Electrical Engineering, Poznan University of Technology, 60-965 Poznan, Poland
3. Institute of Electric Power Engineering and Renewable Energy, Faculty of Electrical Engineering Automatic Control and Informatics, Opole University of Technology, 45-758 Opole, Poland