Remedial Actions to Enhance Stability of Low-Inertia Systems

Increased penetration of renewable generation is expected to replace conventional generators and reduce system inertia. Future low-inertia systems are expected to include additional power sources to enhance stability by mimicking inertia and damping of conventional generators. This paper introduces such remedial actions in the formulation of direct methods for transient stability assessment. We extend our previous work on robust stability and resiliency certificates to include optimal tuning of inertia and damping coefficients for transient stability enhancement. The goal is to limit the fault-on trajectory in order to maintain the system inside its stability region. The advantage of this approach is the ability to guarantee system stability for a wider range of faults eliminating the need to carry out time-consuming simulations. An additional contribution of this paper is a novel formulation of the robust stability and resiliency certificates, which relaxes our optimization problem and allows to obtain significantly better results.