1. Department of Electrical Power Engineering and Mechatronics, School of Engineering, Tallinn University of Technology, 12616 Tallinn, Estonia
2. Department of Electrical and Computer Engineering, College of Engineering, San Diego State University, San Diego, CA 92182, USA
3. Department of Radiotechnic and Embeded Systems, Chernihiv Polytechnic National University, 14027 Chernihiv, Ukraine