1. School of Electric Power, North China University of Water Resources and Electric Power, Zhengzhou 450045, China
2. Hunan Key Laboratory of Renewable Energy Power Technology, Changsha University of Science and Technology, Changsha 410114, China
3. Jiang Xi Hong Ping Pumped Storage Company Limited, Nanchang 330000, China
4. State Grid Hunan Electric Power Company Limited, Changsha 410004, China