Showing papers on "Bounding overwatch published in 1988"
••
TL;DR: A very efficient contingency analysis method for detecting branch megawatt flow violation is presented, based on the linear incremental-power-flow model and consequently does not consider reactive power.
Abstract: A very efficient contingency analysis method for detecting branch megawatt flow violation is presented. The efficiency stems from the use of a bounding criterion that drastically reduces the number of branch-flow computations and limits checking, and the use of state-of-the-art compensation and sparse matrix/vector methods. The method requires no offline setup, is highly efficient, and can handle contingencies with any time of network topology and load/generation changes. The method is based on the linear incremental-power-flow model and consequently does not consider reactive power. >
137 citations
••
TL;DR: In this paper, an assessment of the numerical dispersion (over and undershoot) problem for the skew up-wind finite difference scheme in practical flow simulation has been undertaken.
7 citations
••
01 Jan 1988TL;DR: Extensions which include the temporal aspect, and involve the stochastic modelling of the time taken for a fire to breach a barrier, are discussed.
Abstract: A segregated structure is regarded as a collection of volumes joined together by barriers. A fire, starting in one of the volumes, may spread through its bounding barriers to other volumes. The safety assessment of a vital piece of equipment contained in a particular volume, or passing through several volumes, needs to contain a contribution associated with the risk of damage by fire which starts in or spreads to these crucial volumes. A technique is described for doing this using the directed graph of a reduced network with ‘fire transition’ probabilities assigned to its arcs. This time-independent approach has been implemented in a computer program. Examples illustrating its use are given. Extensions which include the temporal aspect, and involve the stochastic modelling of the time taken for a fire to breach a barrier, are discussed.
2 citations
••
12 Jun 1988TL;DR: A description is given of a way to obtain bounds which will be tight over the class of networks for all possible values of the edge failure rate, which have been shown to be valid for a certain range of edge failure rates.
Abstract: A description is given of a way to obtain bounds which will be tight over the class of networks for all possible values of the edge failure rate. These bounds have been shown to be valid for a certain range of edge failure rates. The author discusses the known bounding methods before proposing the new approach. >
1 citations
••
07 Dec 1988TL;DR: In this article, the authors derive bounds for the outputs and states of systems disturbed either by uncertain inputs or modeling errors, using either boxes or ellipsoids as the constraint sets, and conclude that even if a box-boundbased control system provides more conservative results, as compared to alternate bounding approaches, it is more attractive and desirable because of certain practical implementation issues, such as the limitation on realizable actuator bandwidth.
Abstract: Hard constraint bounding results are summarized along with additional new results. The authors derive bounds for the outputs and the states of systems disturbed either by uncertain inputs or modeling errors, using either boxes or ellipsoids as the constraint sets. The bounding results are summarized, based on either the concept of matrix measures or F.C. Schweppe's (1973) ellipsoidal bounds. The theoretical results are applied to a simplified model of a physically meaningful system, namely, a steam-boiler model, with encouraging results. For the class of nonlinear systems represented by the boiler model, it is concluded that even if a box-bound-based control system provides more conservative results, as compared to alternate bounding approaches, it is more attractive and desirable because of certain practical implementation issues, such as the limitation on realizable actuator bandwidth. >