1. School of Energy and Power Engineering
2. Nanjing University of Science and Technology
3. Nanjing 210094
4. China
5. Department of Micro and Nano Systems Technology
6. University College of Southeast Norway
7. Horten 3184
8. Norway
9. State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources
10. North China Electric Power University
11. Beijing 102206
12. School of Energy and Environment
13. Anhui University of Technology
14. Maanshan 243002
15. Faculty of Physics & Electronic Science
16. Hubei University
17. Wuhan 430062