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The paper proposes the integration of structural monitoring with Building Management Systems for electricity and gas distributions. To assess the state of damage of existing buildings the technics of Structural Health Monitoring (SHM) is adopted. SHM as well as to record the occurrence of sudden structural damage resulting from exceptional events (earthquakes, explosions, shocks and collisions with vehicles, etc.), allows the monitoring of the progressive damage and structural performance under operating conditions through the extraction of the modal parameters of the structure. This approach requires time to process acquired data that, depending on the size of the building and the number of monitored points, varies from minutes to hours. In this paper, an intelligent system is proposed to immediately communicate during an earthquake the overrun of a certain ground shaking threshold so that gas delivery and selected power loads are interrupted, as suggested by current national regulations on structures. The use of low-cost and reduced size accelerometric sensors integrated with Energy Monitoring Systems is proposed in both highrisk earthquake centers and in all “strategic” buildings that must ensure their operation use immediately after the earthquake. The procedure for calibrating the horizontal and vertical acceleration threshold is also sketched.

The novel concepts and definitions of M derivative and M bracket for nonlinear differential algebraic system (NDAS) are introduced, and some related revised results that are similar to the classic differential geometric theory are given. The normal forms of NDAS model are obtained by multi-input multi-output (MIMO) feedback linearization technique. The control expressions derived are based on the linear system theory and the requirements of tracking targets when the relative degree of the system is less than the dimension of the system and the special designated conditions are satisfied. The parametric adaptive controller is obtained for the multimachine power systems with nonlinear loads and undetermined or unknown parameters by the Lyapunov stability theory and method. Index Terms--Electric power systems, M derivative, M involutive, M relative degree, NDAS, nonlinear loads, parametric adaptive control.

Although flexible ac transmission system (FACTS) devices and unified power flow controllers (UPFCs) have proven to be powerful tools for the exploitation of network capacities, their performances with regard to transient stability have not been deeply explored yet. In this work, we propose a methodology to assess preventive control actions through adjustments of UPFC reference signals. This control action does not imply changes in the generation and load asset defined by day-ahead market laws. The representation of UPFC devices in a power system is given through a nonlinear model. The UPFC model includes electrical equivalent circuits, a local control scheme, and a centralized control scheme. Control actions are evaluated through a nonlinear optimization process. The approach is tested on a detailed representation of the Italian national grid and test results are presented. Index Terms--Dynamic security assessment, energy markets, FACTS devices, preventive control, transmission management, unified power flow controller.

Some results of higher dimensional space periodic solution of differential and algebraic systems are presented. The structure preserving models are considered for power systems with loads influenced by periodic disturbance. The existence and uniqueness of periodic solutions for multimachine power systems with nonlinear loads are given. The existent conditions of periodic solution for multimachine power systems with constraints are obtained. Some examples are given to illustrate the feasibility by higher dimensional space periodic solution theory. Index Terms--Differential and algebraic systems (DAS), existence, periodic perturbation, periodic solution, uniqueness.

The implementation of a transient security dispatch (TSD) algorithm for real-time applications is presented. The algorithm, based on the generalized reduced gradient (GRG) method, processes collectively a set of contingencies in order to ensure transient stability for all postulated cases. The massive computation has been decomposed on a cluster of workstations, exploiting the decoupled nature of the GRG method and the benefits of distributed computing. The feasibility of the implementation is shown through tests on a realistic-sized test network. Index Terms--Distributed computing, dynamic security assessment, preventive control, transient security dispatch.

Time-domain solution of a large set of coupled algebraic and ordinary differential equation is an important tool for many applications in power system analysis. The urgent need for online applications as well as the necessity of integrating transient and long-term analysis in a unique code is the main motivation for developing more reliable and fast algorithms. In this paper, a class of algorithms which exploits the so-called parallel-in-time formulation is considered. These algorithms developed to run on vector/parallel computers also give the opportunity to develop new integration rules sharing interesting properties. Parallel-in-time boundary value methods (BVM's) are proposed for implementation in power system transient stability analysis. These methods are characterized by some advantages such as: the possibility to have high accuracy, to use efficiently the same method for stable and unstable problems, to treat stiff problems and to be implemented efficiently on vector/parallel computers. Their application to the solution of linear differential algebraic equations (DAE's) has been proposed in the mathematical literature. In this paper, we extend their use to nonlinear DAE's and demonstrate the existence and uniqueness of the numerical solution as well as the convergence properties of the proposed algorithms. The theoretical results are utilized for the implementation of Newton/relaxation algorithms on a vector/parallel computer. Test results on a realistic network characterized by 662 buses and 91 generators are reported. Index Terms - Boundary Value Methods, parallel computing, transient stability analysis.

Many problems in transient network analysis are characterized by the solution of a simultaneous set of coupled algebraic and ordinary differential equations. The urgent need for on-line applications has motivated power system researchers to develop algorithms which can be implemented on parallel computers. Traditional algorithms for simulating power system dynamics do not readily lend themselves to parallel processing and only a limited amount of parallelism can be achieved. In this paper, a class of algorithms which exploits the concurrent solution of many time steps is presented. By applying a stable integration method, the overall algebraic-differential set of equations can be transformed into a unique algebraic problem at each time step. The dynamic behavior of the system can be obtained by solving an enlarged set of algebraic equations relative to the simultaneous solution of many time steps. A class of relaxation/Newton algorithms can be used to solve this problem efficiently. Furthermore, this formulation permits, easily, the implementation of multigrid techniques. Theoretical aspects about the convergence rates and computational complexity of the proposed algorithms are discussed in the paper. Test results on realistic power systems confirm theoretical expectations and show the promise of a several-fold increase speed over that obtainable by traditional parallel-in-space approaches. The synergism obtainable by parallelism in time and in space can allow high speed-up adequate for on-line implementations of transient stability analysis.

The current status of parallel processing as used in electric power systems analysis is presented. The use of parallel processing is induced by the need for rapid solution in power system problems. For a specific problem, a separate derivation has to be made that could be used as a parallel algorithm. The answer has to done in a parallel machine with compatible architecture and algorithms. The last decade has seen research done on algorithm development and the evaluation of multiprocessor architectures has just began. Hardware development still has no definite path with existing machines suitable only for research work.