North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University and North China Electric Power University - State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources