1. Sichuan University,Department of Electrical Engineering,Chengdu,China
2. Quanzhou Institute of Equipment Manufacturing, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences,Jinjiang,Fujian,China,362200
3. Smart Grid Research Institute, Nanjing Institute of Technology,Nanjing,China,211167
4. School of Automotive and Transportation Engineering, Hefei University of Technology,Hefei,China,230009