when a distribution network consisting of distributed generations (dgs) is disconnected from upstream network, the system may be exposed to severe power imbalance. in order to prevent the damage of power plants, frequency relays operate and remove dgs from the network. in contrast to traditional methods, the main objective in new methods is to keep dg units in service in the islanded distributi...

A class of constrained LQ optimal control problems can be abstractly formulated as seeking a nearest point in a `slice' S \ C where S is an aane subspace of a Hilbert space H and C is the (possibly unbounded) closed convex set corresponding to imposition of the constraint. Subject to a slackness condition, it is shown that the optimal control must then be a `nearest point in C' for some control...

This is an overview of distributed computer control systems from the perspective of control performance and the requirements of a safety-critical application. The common timing issues, here called the timing problems, are stated from a control point of view: control period, control delay, jitter and transient error. seen as disturbances acting on the closed loop via the digital computer system,...

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We give a detailed view of estimation and control problems raised by the drilling process where the distributed nature of the system cannot be ignored. In particular, we focus on the transport phenomena in Managed Pressure Drilling (MPD) and UnderBalanced Operations (UBO), as well as the time-delay mechanisms of the mechanical stick-slip vibrations. These industrial challenges raise increasingl...

1 Institut de Mathématique, Université de Mons, 7000 Mons, Belgium 2Centre de Recherche en Automatique de Nancy (CRAN), Nancy Université, CNRS, 2 Avenue de la Forêt de Haye, 54516 Vandoeuvre-les-Nancy, France 3 Systèmes et Applications des Technologies de l’Information et de l’Energie (SATIE) CNRS, UMR8029-École Normale Supérieure de Cachan, ENS Cachan, France 4Laboratoire des Signaux et Systèm...

We present a spatial domain decomposition (DD) method for the solution of discretized parabolic linear–quadratic optimal control problems. Our DD preconditioners are extensions of Neumann-Neumann DD methods, which have been successfully applied to the solution of single elliptic partial differential equations and of linear–quadratic optimal control problems governed by elliptic equations. We us...