A comparative study of damping schemes on damping generator oscillations

Results of a comparative study of the application of three different compensators, the power system stabilizer (PSS), the static VAR compensator (SVC), and the rectifier current regulator (RCR), for the damping enhancement of generator oscillations in a power system are presented. In order to enhance the dampings of both the mechanical mode and the exciter mode in the system, a unified approach based on modal control theory is proposed for the design of the PSS, the SVC, and the RCR. A proportional-integral-derivative (PID) type controller using generator speed deviation as a modulated signal to generate the desired damping is proposed, and it is shown that both affected system modes can be exactly located at the prespecified positions on the complex plane by the proposed damping schemes. To demonstrate the effectiveness of the proposed PID controllers and their relative merits, a frequency-domain study based on eigenvalue analysis under different operating conditions and a time-domain study based on nonlinear model simulations under disturbance conditions are performed