LI Shijun1,2,4 ,LUO Longfu1 ,LI Weidong3 ,SHEN Yang1 ,DING Liguo1,ZHANG Xizhen2
(1.College of Electrical and Information Engineering, Hunan University, Changsha 410082, China;2.Hunan Provincial Key Laboratory of Wind Generator and Its Control, Hunan Institute of Engineering,Xiangtan 411101,China; 3.Powerchina Zhongnan Engineering Co Ltd, Changsha 410014, China;4.2011 Hunan Province Cooperative Innovation Center for Wind Power Epuipment and Energy Conversion, Xiangtan 411101, China)