1. Department of Electric Motors and Electrotechnics , Kazan National Research Technological University , 68 Karl Marx Str., Kazan, 420015, Russia
2. Department of Methods of Increase of Power Supply Reliability and Power Quality in Distributive Electrical Grids , Kazan State Power Engineering University , 51 Krasnoselskaya Str., Kazan, 420066, Russia
3. Laboratory of Energy System Analysis and Optimisation , Institute of Physical Energetics , 14 Dzerbenes Str., Riga, LV-1006 , Latvia