1. School of Automation Science and Electrical Engineering, Beihang University,Beijing,China,100191
2. Tianmushan Laboratory, Xixi Octagon City,Yuhang District,Hangzhou,China,310023
3. School of Mechanical and Aerospace Engineering, Nanyang Technological University,Singapore,Singapore,639798
4. Power Electronics, Machines and Control Group, University of Nottingham,Nottingham,U.K,NG7 2RD