Options for emergency control of power grids with high penetration of renewables

Power systems are experiencing a historical transformation in their paradigm and architecture. As such, the classical methods ensuring secure operation of power grids, which are largely developed several decades ago, need to be reassessed. At the same time, new generations of smart electronic devices provide fast actuation to smart power grids. Also, transmission resources are continuously installed into the system and will be ubiquitously available in the future. These assets provide new opportunities for power grids' operation controls. In this paper, we sketches the ideas of viable alternatives for traditional remedial actions of power grids with high penetration of renewables, in which the renewables are integrated with synchronverters to mimic the dynamics of conventional generators and transmission lines are equipped with FACTS devices. In these novel emergency control schemes, the power electronics resources are exploited to control the inertia/damping of the imitated generators as well as the susceptances of transmission lines in order to quickly stabilize the power system under emergency situations. The proposed controls are designed by solving convex optimization problems, making them scalable to large scale power grids. Also, these emergency control schemes can be implemented with minor investment by exploiting the plentiful transmission facilities ubiquitously available on the existing power grids.