Transient Stability Analysis of DFIG-based Wind Farm Integrated Power System With Distributed Loads

This paper deals with the transient stability enhancement of a power system integrated with doubly fed induction generator (DFIG) based wind farm by modifying the DFIG output power. Transient stability condition of power systems can be improved by controlling the active power and reactive power output of the wind farm during system disturbances. A modification of the field oriented control of the DFIG is used here which modulates the output power of the wind farm during post fault condition in such a fashion that it helps to minimize the excursions of the relative rotor angles of the nearby synchronous generators. A method to enhance the voltage profile during fault, by injecting reactive power, is also proposed which further enhances the system transient stability. In this method the grid side converter of the DFIG is used to push reactive power to the grid thereby improving the system transient stability. Study is carried out with different combinations of distributed additional local loads and different fault locations in a multi-machine power system. WSCC 3-machine 9-bus system is used for this study. The study is performed in PSCAD/EMTDC platform.