[1] State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing
[2] Qinghai Key Laboratory of Efficient Utilization of Clean Energy, Tus-Institute for Renewable Energy, Qinghai University, Xining
[3] School of Engineering, Xining University, Xining
[4] State Key Laboratory of Power Grid Safety and Energy Conservation, China Electric Power Research Institute, Beijing
[5] Beijing Electric Power Economic and Technological Research Institute Co., Ltd., Beijing