ارايه يك مدل تحليلي غيرخطي براي ميانگين سالانه زمان مصرف روزانه قله بار الكتريكي در كشور

Stability Improvement of Fixed Speed Wind Turbines Using Braking Resistor

Nowadays, stability of wind turbines is an important issue during disturbances of network. In some countries according to the existing regulations wind turbines are allowed connect to grid provided that could keep their stability following voltage sags or disturbances. This paper investigates the stability improvement of a grid connected fixed speed wind farms following disturbances such as faults, using braking resistors. In this study the complete model for wind farm is employed by considering the aerodynamical, mechanical and electrical feature of the system. The stability performance of the system is examined by simulation studies using the DIgSILENT software under different levels of compensation, delay time of circuit breakers following the gird fault conditions. Computer simulation results show the combination of braking resistors and reactive compensation can significantly improve the stability of grid connected wind turbines. Finally, for breaking resistor switching operation, the comparison has been made between two methods of speed signal and voltage signal process