The DYNAMIC STABILITY IMPROVEMENT ANALYSIS FOR AN INTEGRATED GRID-CONNECTED DFIG BASED WIND FARM

Abstract

The performance of the studied OWF is simulated by an equivalent doubly fed induction generator (DFIG) driven by an equivalent wind turbine (WT) while an equivalent squirrel-cage rotor induction generator (SCIG) driven by an equivalent marine-current turbine (MCT) is employed to simulate the
characteristics of the MCF. A damping controller of the STATCOM is designed by using modal control theory to contribute effective damping characteristics to the studied system under different operating conditions. A frequency-domain approach based on a linearized system model using eigenvalue techniques and a time-domain scheme based on a nonlinear system model subject to various disturbances are both employed to simulate the effectiveness of the proposed control scheme. It can be concluded from the simulated results that the proposed STATCOM joined with the designed damping controller is very effective to stabilize the studied system under disturbance conditions. The voltage fluctuations of the AC bus subject to the active-power variations of the studied system can also be effectively controlled by the proposed control scheme. A frequency domain control strategy based on a linearized system structure utilizing eigenvalue techniques and a time domain control scheme based on a nonlinear system model subject to various fluctuations are both employed to simulate the effectiveness of the recommended control approach. It can be finished from the gained responses that the recommended STATCOM combined with the designed with the damping controller is very effective to control the studied system under various voltage inequalities. The voltage changeability like the exterior three phase short circuit faults of the AC bus subject to the active power fluctuations of the studied system can also be effectively maintained by the suggested control strategy.