Steady-state stability analysis of a parallel AC-DC power system containing a static VAr compensator

The paper presents the results of a comparative study on the application of three different compensators, i.e., the power system stabilizer (PSS), the static VAr controller (SVC), and the rectifier current regulator, for damping generator oscillations in a parallel AC-DC power system containing a static VAr compensator. The developed scheme employs generator speed deviation as a feedback signal respectively through the proposed proportional-integral-derivative (PID) controllers to generate individual control inputs for the studied system. The parameters of the PID controllers are determined by using a unified approach based on modal control theory. The mechanical mode and the exciter mode of the system can also be exactly assigned to the desired locations on the complex plane by the proposed algorithm. Dynamic responses based on a nonlinear model simulation under a torque disturbance are also accomplished in order that the effectiveness of the proposed control schemes on damping generator oscillations can be clearly demonstrated.<>