Small Signal Stability Analysis Research Of Wind Farms Of DFIG Type Access To Power System

As an important branch of renewable energy sources, wind power has become one of the most promising renewable energy resources, which bears the most mature technology, the largest application scale and the best commercialized prospects. Especially, the doubly-fed induction generator (DFIG) has become one of the most widely applied variable speed constant frequency wind generating sets in electrical power industry.This thesis firstly introduces the overall structure and working principle of GE1.5MW DFIG and describes the mechanism and function of each control module of DFIG in detail. The equivalent model of wind farm of DFIG type is established. Under the DSAToolsTM-SSAT simulation software environment developed by PowerTech company in Canada, the two-area-four-machine test system and the IEEE10-generator-39-bus test system are employed as examples to study the impacts of different operating conditions of wind farm on electromechanical oscillatory modes and small signal stability with designed two simulation scenarios involving synchronous generators replacing and grid connection of wind farm directly. Some meaningful conclusions and comments are drawn. The IEEE10-generator-39-bus test system is further employed as benchmark to explore and exploit the small signal stability constrained total transfer capability (TTC) issue based on three kinds of power transfer modes, different load models and disturbance conditions with the designed simulation scenarios involving no wind farm integration, synchronous generator replacing and grid connection of wind farm directly. The numerical simulation results show that under different load models, power transfer modes, the integration of wind farm of DFIG type has great impacts on the TTC of power system with small signal stability constraints taken into account.