This research project aims at developing methods to help integrate clean energy into the electric power grid. We are at the cusp of a historic transformation of our energy system into a more sustainable form in the coming decades. One of the key technical challenges is balancing supply and demand at all times at all points of grid. Traditionally, supply-demand balance is maintained by adapting generation to fluctuating demand. This will become ineffective in the future because sources of renewable generation of electricity such as wind and solar power are random and uncontrollable. On the other hand, there will be more and more distributed energy resources such as electric vehicles, smart buildings, smart appliances, storage devices, and other power electronic controllers that not only consume, but may also sense, compute, communicate and actuate. We will design methods for ubiquitous, continuous load-side frequency regulation to supplement the current generation-side control, prove the stability and optimality of these methods in a large network of distributed energy resources, and study their interaction with generator-side control.
A cyberphysical network such as a smart grid consists of a physical network governed by its own laws of physics and a cyber-network that senses, communicates, computes, and actuates on the physical network. Our starting point is the observation that the topology of the cyber-network may be different from that of the physical network. For instance, not every node in the physical network may have sensors or controllers, and this constrains the topology of the cyber-network. On the other hand, two nodes that are not directly connected in the physical network may be able to communicate, e.g., through a wireless channel, and this provides an extra degree of freedom for the design of the cyber-network. We will develop a theory to clarify the impact of the cyber-network on the stability and optimality of the physical network, design effective cyber-networks and frequency regulation algorithms based on the theoretical insights, and validate these designs through simulations.
