1. State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071003, China
2. Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defence, North China Electric Power University, Baoding 071003, China
3. China Huadian Engineering CO., LTD, Beijing 100160, China
4. China Huadian Hong Kong Company Limited, Beijing 100031, China