Multiarea system reliability: The economic evaluation of system security criteria

The advent of competitive electricity markets has resulted in the operation of the system very near its security limits over increasingly longer periods. A particular need for system security assessment studies is the rapid assessment of the impacts of multiple-line outages in the power grid so as to be able to effectively deal with the situations of cascading outages, including cases resulting in system separation into one or more islands. In this dissertation, we develop an analytic expression for the generalized line outage distribution factors (GLODFs) which we use to assess whether the post-outage flows violate any line flow limits under multiple-line outages. The GLODFs are particularly useful to analyze the complications arising from the multiple-line outages, such as detection of island formation. Our proposed approach to detect island formation combines the graph-theoretic connectivity characterization with the algebraic expressions for the GLODFs. The approach can be used to identify the subset of outaged lines that results in system separation. A particularly noteworthy aspect is the numerical efficiency of the approach due to its low computational requirements -- a function simply of the number of outaged lines and not of the size of the system. The approach's computational efficiency enables its effective application to the formulation of appropriate preventive/corrective control actions in multiple-line outage contingencies, particularly those that involve the domino effect of cascading outages.;The maintenance of secure system operations is a highly challenging task that became even more complex with the prominence of electricity markets. We use the insights we gained into the tight coupling between market and system operations under restructuring to characterize analytically the interrelationships between the secure power system operations and the performance of the electricity markets. Such a characterization allows the development of an integrated analysis approach to quantify the economics of secure power system operations. This approach permits the quantification of the market performance as a function of security criterion and provides, for the first time, the means to provide an economic justification for a modification the security criterion. Furthermore, the approach is useful for the cost/benefit analysis of network improvements to mitigate the market performance impacts of a set of contingencies and their associated security control actions. An important application is to the assessment of the impacts of specific behavioral changes in market participants on system security. The generalization of the approach is made by its extension to quantitatively characterize the linkages between the real-time system operations and the day-ahead markets (DAMs) and their associated real-time markets (RTMs) for use in a multi-settlement environment. The extended approach provides the ability to explicitly show that the auction surplus attained in the multi-settlement system is equivalent to the sum of the auction surpluses attained in each RTM. Therefore, the mere presence of the DAMs results in surplus transfers among market participants. Furthermore, the extended approach provides a very useful tool to analyze the nature of the DAM-RTM price deviations and the impacts of financial entities on near-real-time system security.;We illustrate the application of the proposed approaches on the large-scale ISO New England system in a number of studies. The results provide useful insights into the multifaceted nature of issues that arise in the today's tightly coupled market and system operations. In fact, the studies on the economics of the system security provide important insights into the role of price-responsive demand and that of specific selected security control actions measured by the economic efficiency of the electricity markets. (Abstract shortened by UMI.)...