Adequacy of Lyapunov Control of Power Systems Considering Modelling Details and Control Indices

Nonlinear excitation controllers for power systems are considered as promising replacements for their linear counterparts, such as power system stabilizers (PSSs). However, Lyapunov based nonlinear controllers currently available in literature have been derived using simplified third order machine dynamics and have not been tested on realistic power system models, and the costs associated with these controllers have also not been studied. The paper aims to assess the performance of existing Lyapunov controllers for a detailed benchmark power system model. Two new Lyapunov based nonlinear controllers have been derived using IEEE recommended subtransient machine model, and their performance and costs have been compared with existing methods. The controllers have been evaluated using metrics for both small signal stability and transient stability. It has been proven theoretically (via stability analysis) and demonstrated via simulations that proposed Lyapunov controllers are more viable options for control of power system oscillatory dynamics. It has also been demonstrated that detailed subtransient model is required for accurate estimation of states via dynamic state estimation for use in the realization of Lyapunov controllers.