Nonlinear design of excitation controller and power system stabilizer for voltage regulation and transient stability

This paper presents the nonlinear design of excitation controller and power system stabilizer (PSS) aimed at ensuring transient stability and satisfactory post-fault voltage regulation following a large disturbance. The proposed design offers the possibility to select the PSS gains so as to achieve both swings damping in an assigned time interval and desired attenuation of disturbances arising from the excitation control loop. As concerns the excitation controller design it is based on the nonlinear compensation technique and ensures a quick sustainment of the regulated voltage after that the fault is cleared. Simulation results carried-out on a four-nodes power system model show the goodness of the proposed design methodology with a reference to a severe large disturbance represented by a three-phase short-circuit near the generator terminals.