The objective of this research is to study the fundamental interactions and influences that individual components of a power system have on each other and the overall effect of these interactions on system performance. The approach uses a game-theoretic model of the power system to develop a framework for a new class of distributed control methods. In this new model, system components use energy resources to compete for local and global objectives such as voltage, current, power, or energy. The intellectual merit is of this work is in its potential to improve control of interconnected power components. Control has typically been one of two extremes: either completely localized control (focused on local objectives) or a centralized control scheme requiring extensive communications, infrastructure, and a single-point of failure. The proposed approach considers how each different local objective interacts across the system. This will result in an operating point that is a global balance of local objectives. This work will determine how the fundamental interactions of the components contribute to, or degrade from, the higher-level objectives of the overall system, such as stability, survivability, and efficiency. The broader impacts will extend to electrical power networks at all levels where more diverse sources and loads are being utilized, and new technologies are being driven by an ever-increasing demand for performance, stability, efficiency, and flexibility. This new approach to energy control and management will strengthen education objectives by enhancing the content of graduate and undergraduate classes, as well as adding meaningful laboratory experiences.
This research proposed to develop a framework for a new class of distributed control methods for interconnected energy components such as sources, loads storage in microgrids based on a game-theoretic model of the power system. In this new model, the system components use energy resources as a currency to compete for local and global objectives such as power or voltage. This competition does not imply winners and losers where the objectives are diametrically opposed. On the contrary, a power system can be a non-zero-sum game where it is possible for all players to meet and exceed objectives. However, when all objectives cannot be met, it is especially necessary to have a method that mitigates the conflicting operation. Intellectual Merits The control of the interconnected power components has typically been one of two extremes: either completely localized control focused on local objectives or a centralized control scheme requiring extensive communications, infrastructure, and a single-point of failure. A better approach is to consider how all the different local objectives such as voltage, frequency, and power, interact across the system. This leads to an operating point that is a global balance of local objectives. This project has produced great success in determining how the fundamental interactions of the components contribute to, or degrades from, the higher level objectives of the overall system, such as stability, survivability, and efficiency. Some of the highlights of finding include: 1) An electric power system can be modeled not in terms of energy balance and not just voltages and current. 2) There is a systematic way to determine the best minimal structure of communications between energy components that yields the most desired outcomes. 3) When a set of loads have a choice in where they can draw power in a multiple bus system, game-theory provides a direct solution for optimal system configuration. 4) The dynamic startup for a microgrid from a cold-start to steady-state operation requires a set of optimally determined trajectories. 5) Very complicated reactions and dynamic responses of a microgrid can be calculated in the design and programmed into low-cost and fast response memory as a look-up table instead of complicated and computationally intensive microprocessors. Broader Impacts Electrical power networks at all levels are being populated with more diverse sources and loads, while demanding an ever-increasing standard for performance, stability, efficiency, and flexibility. Current control methodologies are not keeping pace and are not adequate for these new systems. The broader impact of this project will be in the innovative approach to the distributed control of energy that is based on a competitive structure. This new approach will impact a myriad of applications, including renewable and alternative energy. For example, the energy output from sources such as wind and solar is not dispatchable. Therefore, the rest of the system needs to compete for local energy resources to accomplish global objectives. This new approach to energy control and management has also strengthened education objectives by enhancing the content of graduate and undergraduate classes, as well as adding meaningful laboratory experiences. The results of the project have been widely disseminated to the engineering community through technical literature and conference.
