1. Electric Power Research Institute, State Grid Jiangsu Electric Power Co., Ltd., Nanjing 211103, China
2. College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
3. 724 Research Institute, China State Shipbuilding Corporation, Nanjing 211106, China
4. Electrical Engineering and Industrial Informatics, Politechnica University of Timisoara, 300699 Hunedoara, Romania