1. North China Electric Power University, Baoding, China
2. Xuchang Electric Power Supply Company of State Grid Henan Electric Power Corporation, Xuchang, China
3. State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, China
4. China Electric Power Research Institute, Beijing, China
5. State Grid Henan Electric Power Research Institute, Zhengzhou, China