Squirrel-cage induction generator (SCIG), as its structural and economic advantages, has been widely utilized in large wind farms in China. However, the large wind farm composed of induction generators will cause obvious problems to the power system stability due to the dependency on reactive power. At the same time, Doubly-fed induction generator (DFIG), as a new type of wind turbine generator, has excellent dynamic characteristics for operation of wind farms. With the increase in penetration of wind power in power systems, more and more wind farms will use both SCIG and DFIG. In this case, the dynamic characteristic of wind farm on power systems is becoming an important issue especially in terms of the voltage stability. This article is to show by means of simulations the dynamic performance of wind farm linked to power system under the circumstances of network disturbances. Furthermore, the interaction between the SCIGs and DFIGs has also been investigated. A detailed model of wind farms is presented through the plat root of MATLAB/SIMULINK. The simulation results demonstrate that the DFIG applications will largely improve the dynamic performance of wind farm in certain conditions, if the DFIGs could be applied reasonably, the voltage stability of the wind farm will be largely improved and even low voltage ride through(LVRT) characteristic of SCIGs, which may be a good solution to reduce the high dependence of costly reactive power compensation equipment(Some flexible AC transmission systems devices like SVC, STATCOM) to some extent.
Comparative Analysis of DFIG based Wind Farm Connected Power System using Fuzzy Controller based FACTS
