The performance research of large scale wind farm connected to external power grid

At present, the wind power generators widely used in China are the squirrel cage induction generators (SCIG). With the rapid increase in penetration of wind power in power systems, the dynamic influence of a large wind farm on power systems is becoming an important issue for integration and operation of wind farms. So grid codes require that all new installed WTGs should have the capability of fault ride through (FRT) or low voltage ride through (LVRT). This capability means that wind generation should have the ability to remain connected during faults (outside their protection zone) and voltage dip conditions within certain limits. Based on the appropriate wind farm models, the dynamic performance of wind farm during faults and the effect of FRT with static VAR compensation (SVC) equiped is researched. Furthermore, the effect of FRT when doubly-fed induction generators (DFIG) connected in wind farm was researched. These models of wind farm were developed and compared by simulation studies in the PSCAD/EMTDC environment under different wind fluctuation conditions as well as gird fault conditions, which took Nanao wind farm connected to the Shantou power grid of Guangdong Province, China as an example. The simulation results showed that SVC can provide fast dynamic reactive power support, DFIG be able to provide reactive power support according to the requirement reactive power value of FSIG terminal very well.