1. National Laboratory of Industrial Control Technology, College of Electrical Engineering, Zhejiang University, Hangzhou, China
2. College of Electrical and Power Engineering, Taiyuan University of Technology, Taiyuan, China
3. School of Information and Electrical Engineering, Zhejiang University City College, Hangzhou, China
4. National Laboratory of Industrial Control Technology, College of Electrical Engineering, Huzhou Institute, Zhejiang University, Hangzhou, China