Compensation of Distribution System Voltage using DVR

A dynamic voltage restorer (DVR) is a power-electronic controller that can protect sensitive loads from disturbances in the supply system. In this paper, it is demonstrated that this device can tightly regulate the voltage at the load terminal against imbalance or harmonic in the source side. The behavior of the device is studied through steady-state analysis, and limits to achievable performance are found. This analysis is extended to the study of transient operation where the generation of the reference voltage of the DVR is discussed. Once the reference signals are generated, they are tracked using a switching band scheme. A suitable structure in which the DVR is realized by voltage-source inverters (VSIs) is also discussed. Particular emphasis to the rating of this device is provided. Extensive simulation results are included to illustrate the operating principles of a DVR

An automatic electrical distribution system

Computer controlled electric power distribution system for aerospace system

Distribution and metering system for soil samples

Electromechanical assembly with movable hopper, commanded to put soil samples into inlet sorts of sampling valves, distributes metered volumes of soil samples into test cells

Microcanonical Origin of the Maximum Entropy Principle for Open Systems

The canonical ensemble describes an open system in equilibrium with a heat bath of fixed temperature. The probability distribution of such a system, the Boltzmann distribution, is derived from the uniform probability distribution of the closed universe consisting of the open system and the heat bath, by taking the limit where the heat bath is much larger than the system of interest. Alternatively, the Boltzmann distribution can be derived from the Maximum Entropy Principle, where the Gibbs-Shannon entropy is maximized under the constraint that the mean energy of the open system is fixed. To make the connection between these two apparently distinct methods for deriving the Boltzmann distribution, it is first shown that the uniform distribution for a microcanonical distribution is obtained from the Maximum Entropy Principle applied to a closed system. Then I show that the target function in the Maximum Entropy Principle for the open system, is obtained by partial maximization of Gibbs-Shannon entropy of the closed universe over the microstate probability distributions of the heat bath. Thus, microcanonical origin of the Entropy Maximization procedure for an open system, is established in a rigorous manner, showing the equivalence between apparently two distinct approaches for deriving the Boltzmann distribution. By extending the mathematical formalism to dynamical paths, the result may also provide an alternative justification for the principle of path entropy maximization as well.Comment: 12 pages, no figur

Video distribution system cost model

A cost model that can be used to systematically identify the costs of procuring and operating satellite linked communications systems is described. The user defines a network configuration by specifying the location of each participating site, the interconnection requirements, and the transmission paths available for the uplink (studio to satellite), downlink (satellite to audience), and voice talkback (between audience and studio) segments of the network. The model uses this information to calculate the least expensive signal distribution path for each participating site. Cost estimates are broken downy by capital, installation, lease, operations and maintenance. The design of the model permits flexibility in specifying network and cost structure

3.3 Gigahertz Clocked Quantum Key Distribution System

A fibre-based quantum key distribution system operating up to a clock frequency of 3.3GHz is presented. The system demonstrates significantly increased key exchange rate potential and operates at a wavelength of 850nm.Comment: Presented at ECOC 05, Glasgow, UK, (September 2005

Strategic planning optimisation of "Napoli Est" water distribution system

The District Meter Areas (DMA) design is an innovative methodology of water networks management, based on the pressure patterns control and on the water flows monitoring, in order to reduce water losses and to optimize the water systems management. A District Meter Area is an area supplied from few water inputs, into which discharges can be easily measured to determine leaks. So, the DMA design represents an alternative to the traditional approach based on heavy looped distribution network. In the present paper the DMA design of the “Napoli Est” water distribution system (approximately 65.000÷70.000 customers), performed with the support of the Water Agency ARIN S.p.A., is discussed. After analysis of authorized consumption, by means of a monitoring campaign of water flows over the area, the system water balance was performed, showing significant water losses, as a consequence of high pressure patterns. This situation was confirmed by the high number of maintenance operations performed in the area during the year 2005. In order to characterize the piezometric heads on the network, ARIN S.p.A. supplied to the installation of six pressure transducers in the most vulnerable areas. The water level in the supply reservoir was also measured in order to estimate its influence on the network pressure heads. Hydraulic simulations were carried out with the EPANET software version 2.0 applied to a network layout resulted from the system “skeletonization”, achieved by eliminating out of order pipes, integrating pipelines of same diameter and roughness, replacing dead-end branches and small networks supplied by a single junction with an equivalent discharge. After the skeletonizated network was calibrated, several hypothesis of designing and implementing DMA to reduce physical losses were performed, providing adequate operating pressure of the system. Many numerical simulations were performed to guarantee adequate head pressure especially for peak hours demand, break of transmission mains and fire hydrant service. A chlorine residuals analysis was also effected, by simulating the transport and decay of chlorine through the network. District Meter Areas, therefore, were designed, and the corresponding hydraulic and water quality investigations and simulations were carried out. Six District Meter Areas were planned, assembling 14 intercepting valves and 9 pressure reducing valves to prevent the downstream pressure head from exceeding the set value, achieving a remarkable water saving, approximately equal to 34% of the physical losses, corresponding to 16% of system input volume