The first wind turbine developed in China dates back to the 1970 s,which joined the power grid in the Sijiao Island,Zhejiang
Province.After the 18-kW wind turbine,200 kW,250 kW,600 kW,
and 750 kW fixed pitch wind turbines were developed,and the MW level wind turbine was developed in 2003.Currently,the majority of wind turbines in China are 1.5 to 3 MW.In 2013,the 6-
MW offshore wind turbine succeeded in power inegration,and the 12-MW turbine is understudy [15].
Fixed pitch wind turbines are no longer in production due to the evolution of wind power technologies.There are mainly three configurations of pitch controlled wind turbines in the Chinese
market.