1. Warwick Manufacturing Group, The University of Warwick, Coventry, U.K.
2. Queen's University Belfast, Belfast, U.K.
3. State Key Laboratory of Power Systems, Department of Electrical Engineering, Tsinghua University, Beijing, China
4. School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, China
5. School of Computer and Communication Engineering, University of Science and Technology Beijing, Beijing, China