1. School of Energy, Power and Mechanical Engineering, North China Electric Power University, Baoding071000, China
2. Hebei Key Laboratory of Electric Machinery Health Maintenance & Failure Prevention, North China Electric Power University, Baoding071003, China
3. Key Laboratory of Icing and Anti/De-icing, China Aerodynamics Research and Development Center, Mianyang621000, Sichuan, China
4. Electric Power Research Institute, China South Power Grid, Guangzhou510013, China
5. School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing102206, China