Power transmission grid infrastructures deliver electricity across large distance and are vital to the functioning of modern society. Increasingly these setups embody highly-coupled cyber-physical systems where advanced telecommunications networks are used to send status and control information to operate power transmission grid components, i.e., "smart grids". However, due to the high inter-dependency between the communication and power grid network layers, failure events can lead to further loss of control of key grid components, i.e., even if they are undamaged. In turn, such dependencies can exacerbate cascading failures and lead to larger electricity blackouts, particularly under disaster conditions. As a result, a range of studies have looked at modelling failures in interdependent smart grids. However most of these designs have not considered the use of proactive network-level survivability schemes. Indeed, these strategies can help maintain vital control connectivity during failures and potentially lead to reduced outages. Hence this thesis addresses this critical area and applies connection protection methodologies to reduce communication/control disruption in transmission grids. The performance of these schemes is then analyzed using detailed simulation for a sample IEEE transmission grid. Overall findings show a good reduction in the number of overloaded transmission lines when applying network-level recovery schemes.

Since the advent of the computer in the late 1950s, scientists and engineers have pushed the limits of the computing power available to them to solve physical problems via computational simulations. Early computer languages evaluated program logic in a sequential manner, thereby forcing the designer to think of the problem solution in terms of a sequential process. Object-oriented analysis and design have introduced new concepts for solving systems of engineering problems. The term object-oriented was first introduced by Alan Kay [1] in the late 1960s; however, mainstream incorporation of object-oriented programming did not occur until the mid- to late 1990s. The principles and methods underlying object-oriented programming center around objects that communicate with one another and work together to model the physical system. Program functions and data are grouped together to represent the objects. This dissertation extends object-oriented modeling concepts to model algorithms in a generic manner for solving interconnected, multi-domain problems. This work is based on an extension of Graph Trace Analysis (GTA) which was originally developed in the 1990's for power distribution system design. Because of GTA's ability to combine and restructure analysis methodologies from a variety of problem domains, it is now being used for integrated power distribution and transmission system design, operations and control. Over the last few years research has begun to formalize GTA into a multidiscipline approach that uses generic algorithms and a common model-based analysis framework. This dissertation provides an overview of the concepts used in GTA, and then discusses the main problems and potential generic algorithm based solutions associated with design and control of interdependent reconfigurable systems. These include: • Decoupling analysis into distinct component and system level equations. • Using iterator based topology management and algorithms instead of matrices. • Using composition to implement polymorphism and simplify data management. • Using dependency components to structure analysis across different systems types. • Defining component level equations for power, gas and fluid systems in terms of across and though variables. This dissertation presents a methodology for solving interdependent, multi-domain networks with generic algorithms. The methodology enables modeling of very large systems and the solution of the systems can be accomplished without the need for matrix solvers. The solution technique incorporates a binary search algorithm for accelerating the solution of looped systems. Introduction of generic algorithms enables the system solver to be written such that it is independent of the system type. Example fluid and electrical systems are solved to illustrate the generic nature of the approach. / Ph. D.