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[en] Bell Canada and Hydro-Quebec have developed a joint program on internal environmental assessments (IEA) of the distribution system. The program was designed to cover all distribution line modernization and construction projects. The implementation of the IEA was carried out in three phases: (1) tool development including training needs, (2) a pilot project, and (3) full implementation throughout the distribution system. The general IEA method and the 'General Guide on IEA' were described in detail. Impact categories, grids and job aids and a follow-up guide, and environmental training programs were described from the first phase of development. The pilot project of phase 2 was used to evaluate the procedure. Projects were evaluated by environmental specialists for relevance of carrying out an environmental assessment. Useful elements and difficulties with the process were also scrutinized. The complete process was to be applied to over 25,000 distribution system elements per year. 2 refs
[en] The power distribution systems considered for the ATLAS Inner Tracker Upgrade include linear voltage regulators on the front-end chips. In the paper we present two designs: a classical voltage regulator based on an NMOS transistor as the pass element, and an LDO voltage regulator employing a PMOS device. Both prototype regulators have been implemented in the 130 nm CMOS process and are foreseen to be integrated in the ABC130 front-end chip. In the paper the designs as well as the pre- and post-radiation test results for both prototypes are presented and discussed.
[en] Islanding operation of distributed generation becomes a more appealing operation since large numbers of distributed generation have been installed worldwide. Islanding operation can improve the network reliability as the distributed generation continues providing electrical power for consumers when grid outages occur. However, the protection scheme for the islanding condition is one factor that hinders the realization. The setting of overcurrent relays on distribution network is calculated based on grid-connected condition hence the relay often fails to protect the network during islanding condition. Therefore, this paper proposes a method to establish overcurrent relay settings that coordinate correctly for both islanding and grid connected. The method tries to find a compromise between the setting for grid-connected and grid disconnected condition. The results of a case study show that method has successfully obtained a setting which provides correct coordination of the standard inverse overcurrent relay for both grid-connected an islanding condition. (paper)
[en] A 1996 European directive put an end on power production and dispatching monopolies in Europe. The distribution grids became essential structures opened to all power producers and suppliers in exchange for the payment of a fee set by an independent regulatory commission. These grids and networks that are strongly interconnected at the European scale have to play with the specificities of each country. For instance the French power demand is strongly correlated with the temperature as most buildings relies on electricity for heating. Another specificity is that each country is free to choose its energy mix and its production means so German mix relies mainly on coal and lignite while France chose nuclear power. Today's grids are challenged because they have to absorb a growing part of renewable energies and they face also the development of auto-consumption. The solution that is looming is the coexistence of large interconnected European grids with small networks whose meshing is at the district scale to satisfy collective production and auto-consumption. (A.C.)
[en] We have proposed a 3 phase, 100 MVA, 154 kV class HTS transformer substituting for a 60 MVA conventional transformer. The power transformer of 154 kV class has a tertiary winding besides primary and secondary windings. So the HTS transformer should have the 3rd superconducting winding. In this paper, we designed conceptually the structure of the superconducting windings of a single phase 33 MVA transformer. The electrical characteristics of the HTS transformer such as % impedance and AC loss vary with the arrangement of the windings and gaps between windings. We analyzed the effects of the winding parameters, evaluated the cost of each design, and proposed a suitable HTS transformer model for future power distribution system.
[en] It would be easy to attribute the collapse of the futures market in California electricity to the alleged manipulations of over-the-counter traders. This paper provides evidence to the contrary. Findings reveal an active market that lost the speculative and small investor interest, leaving hedgers to face hedgers in a volatile and less active arena. Hedge ratio analysis shows an erratic price-matching ability that many times suggested a long hedge when a short would be expected. Overall, contract failure could be attributed to inaccurate hedging opportunities and lack of speculative interest to keep the market going during lulls in hedging demand
[en] In the process of developing a methodology for assessing the energy security of RA, the following logical methods for assessment can be distinguished: hierarchical, situational, cooperative based on the assessments of the branch specialists. In the process of studying these methods, it is important to use statistical mechanisms. The paper analyzes the dependence of indicators characterizing the security of the RA power system in the RStudio programming system and proposes a method for managing the RA energy security
[en] The reliability of power supply is no longer a matter of course. Savings, bargain, hunters and complex systems undermine the much praised operational reliability. An analysis of the risks involved is an obvious measure to take. But the problem is: who feels responsible for the entire electricity supply structure?