1. Engineering Institute, Yantai Nanshan University, Yantai, People’s Republic of China
2. School of Automation & Electronic Engineering, Qingdao University of Science & Technology, Qingdao, People’s Republic of China
3. Powerchina Huadong Engineering Corporation Limited, Hangzhou, People’s Republic of China
4. Nanshan Electric Power Company, Yantai, People’s Republic of China