Abstract: A method of assessing an electrical power system is provided that includes performing a plurality of contingencies using a mathematical model of the system and determining a representative solution for each contingency. For each bus and contingency, symptoms of system stress exhibited in the representative solution are tabulated. Each contingency is categorized into a contingency cluster based on its representative solution, and those buses having a highest number of the symptoms of system stress for each contingency categorized within a respective contingency cluster are sorted into a group associated therewith. The contingency clusters are arranged into a ranking based on its effect on the network, and a location for a network enhancement is selected from a group of buses associated with a contingency cluster of the ranking that has a largest effect on the network and also includes buses as a result of the sorting.

Abstract: A method of locating enhancements for improving voltage stability security of an electric power transmission system having a plurality of buses and a plurality of sources of reactive reserves coupled thereto. The plurality of buses are grouped into a plurality of voltage control areas such that each of the buses within each voltage control area has a similar corresponding reactive power versus voltage relationship. A first voltage control area is determined for locating a first enhancement, wherein the first voltage control area exhibits therein a difference in internal reactive loss that exceeds a loss threshold. A second voltage control area is determined for locating a second enhancement, wherein the second voltage control area exhibits therein a difference in reactive reserves that exceeds a reactive reserve threshold. The first and second enhancements may include switchable shunt capacitors, synchronous voltage condensers, static var compensators, or a combination thereof.

Abstract: A method for performing a voltage stability security assessment for a region of an electric power transmission system having a plurality of buses and a plurality of sources of reactive reserves coupled thereto. The plurality of buses are grouped into a plurality of voltage control areas such that each of the buses within each voltage control area has a substantially similar reactive margin and voltage at the minimum of the corresponding reactive power versus voltage relationship. A corresponding reactive reserve basin is determined for each of at least one of the voltage control areas. Each reactive reserve basin comprises at least one of the sources of reactive reserves selected in dependence upon a measure of the reactive reserves depleted at a predetermined operating point of the electric power transmission system. A single contingency analysis is performed by computing a corresponding quantity for each reactive reserve basin in response to each of a plurality of single contingencies.