1. Associate Professor Institute of Heat Engineering, Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, Warsaw 00-665, Poland e-mail:
2. Assistant Professor Institute of Electric Machines, Faculty of Electrical Engineering, Warsaw University of Technology, Warsaw 00-661, Poland e-mail:
3. Adjunct Institute of Electric Power Engineering, Faculty of Electrical Engineering, Warsaw University of Technology, Warsaw 00-661, Poland e-mail: