The Simulation Study Of FACTS In Wind Power Systems

Wind power is an important renewable energy, wind power generation technology is one of most important direction in the reseach field of power system. Because of the fluctuation and intermittene of wind power, the wind farm which consists of many wind turbines grid connected would bring great problem to the power system stability. Result in voltage level fall at PCC of wind farm,and produce certain influence to power quality of power grid.Flexible AC Transmission Systems(FACTS) can enhance the safety and stability of AC systems.Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM) are two widely used devices of FACTS. SVC and STATCOM can be integrated into grid as reactive power compensators to improve voltage stability of wind farm grid connection.Through the research of the working principle of TCR+FC Type SVC and the characteristics of wind farm to be aimed at advantages and disadvantages of Fuzzy Control method and PI Control method,combining Fuzzy Control and PI Control method ,the Fuzzy-PI Compound Control method for SVC was proposed. Analysised by MATLAB simulation software,the simulation results prove the validity of the control method .And this kind of SVC which is used Fuzzy-PI Control method is integrated at the outlet busbar of wind farm as reactive power compensators. The SVC integrated compensating the reactive power, restraining fluctuation of grid voltage of bus,so that the accident of tripping of wind turbines caused by the low voltage of bus in varied wind could be avoided.Cascaded H-Bridge STATCOM represents the development direction of the STATCOM, in order to improve performance of reactive power compensation,this paper analys is the H- Bridge STATCOM principle and topology, adopt the method of CPS-SPWM Direct Current Control improved by Fuzzy PI Adaptive control technology,Cascaded H-Bridge STATCOM is designed , and the STATCOM is integrated at the outlet busbar of wind farm as reactive power compensators. The simulation results prove the roles of STATCOM integrated at the outlet busbar of wind farm for voltage stability. Compared to SVC , application STATCOM device,the voltage of bus changes more gently ,approaching 1.0 pu much more and the effect of voltage stability is better.