A framework for distributed decision making in electric energy systems with intermittent resources

This thesis is motivated by the fact that the increasing presences of intermittent energy resources such as wind and photovoltaic power has raised many challenging questions to the electric energy system operations. Given that (1) most of these intermittent resources are geographically disperse, and (2) sensing and actuation devices are more affordable, a distributed decision-making framework becomes not only possible, but necessary for future electric energy systems.;In Chapter 3 we develop two possible distributed criteria which ensure linearized dynamical stability. The first criterion provides a self-stabilizable scenario without any information exchange between the modules and the system operator. The second criterion provides a stabilization scenario which requires minimum information exchange between the modules and the system operator. Numerical examples show that criterion one is more conservative than criterion two.;In Chapter 4 we propose a look-ahead distributed approach to economic dispatch in electric energy systems. Based on predicting the output from the intermittent resource, a look-ahead optimal control algorithm could be adopted for dispatching the available generation with the objective of minimizing the total production cost. Compared with the static economic dispatch which treats intermittent resources as uncertain negative loads, the proposed method could lower the total generation cost by determining the optimal generation injection to the grid from the intermittent resources. The proposed method is directly applicable to managing systems with large presence of intermittent renewable energy resources such as wind and solar.;The proposed approach provides a theoretical framework for systematic integration of sustainable energy resources, such as wind and solar, with specifiable information flow between the modules and the system operator. In Chapter 5 an online information exchange protocol is proposed for built stabilization and dispatch purposes. The required communication rate is compatible with the existing supervisory control and data acquisition (SCADA) system.;In the proposed framework, a group of energy converting components in the system is considered a module and is represented in terms of its local variables and the interaction variables between the modules and the transmission system. The dynamics of generator modules are characterized based on first principles, whereas dynamics of load modules are characterized based on the fast, sampling data collected from the Phasor Measurement Units (PMU). By incorporating the dynamics of load modules. The proposed dynamical model preserves the structure of the interconnected power system, which lends itself to online distributed analysis and control. This is contrasted by the conventional off-line simulation-based approach to integrating disperse intermittent resources. Based on the proposed model, we show that both the short term stabilization and longer terns scheduling problems are solvable using a distributed approach.