1. Riga Technical University,Faculty of Electrical and Environmental Engineering,Riga,Latvia
2. College of Engineering and Technology, American University of the Middle East,Kuwait
3. Kaunas University of Technology,Department of Electrical Power Systems,Kaunas,Lithuania
4. JSC Augstsprieguma tikls (TSO),Riga,Latvia
5. Faculty of Electrical and Environmental Engineering,Riga,Latvia