| This dissertation is concerned with the decision and control process associated with the restoration of service in an electric power system that has lost some of its load and/or has separated into electrical islands as a result of a major system disturbance. This restoration control problem is formulated here as a multi-objective, multi-stage, combinatorial, dynamic optimization problem, and is solved using a hierarchical interactive approach. That is, the time-hierarchy inherent in the determination and execution of the restoration actions is exploited to decompose the overall control problem into three layers, namely adaptive, optimizing, and direct; restorative control actions are then determined and executed by the appropriate layer according to the time frame available for doing so. The decision of what level to invoke at each stage of the restoration procedure is made by a restoration coordinator with inputs from the system planner or operator (through an interactive interface).; The optimizing layer is thoroughly developed in this dissertation; this represents the first application of optimization theory to restoration control. The problem (or function) in this context is that of maximal load demand allocation. This control problem is addressed by means of a decoupling procedure which partitions it into a sequence of active and reactive allocation subproblems. It is shown that (with minor assumptions) the active subproblem can be formally solved via a direct application of the generalized Benders decomposition. Additionally, the optimizing control function was implemented in the form of a computer program, and was extensively tested using power systems of up to 118 buses.; The direct control layer is also developed in detail. Two direct control functions are identified as key to the success of the restoration process, namely semi-automatic component reconnection, and semi-automatic load restoration. Finally, the dissertation develops the conceptual details of the integration of the proposed restoration approach within the framework of centralized control. |
