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[en] Highlights: • Current distribution pricing does not meet key regulatory principles. • Expert views informed models of innovative network pricing for a smart grid. • Multiple trade-offs between innovative pricing approaches and regulatory principals. • Higher base costs, per unit charge and general tax facilitate low carbon networks. • Facilitation of data sharing, management and communication is essential. - Abstract: This paper outlines how current distribution network pricing can be revised to enable transition to a smart grid in a low-carbon economy. Using insights from expert interviews, it highlights multiple trade-offs between innovative pricing approaches and regulatory principles which might be resolved by a political decision on how the costs should be recovered or socialised. It then identifies four essentials for a successful implementation of a new mechanism: (i) Closer collaboration between TSO and DNO/DSO concerning local dispatch to improve system efficiency. (ii) Installation of smart meters to collect data providing information about the actual contribution to the grid utilisation of each customer. (iii) Intensified cooperation between supplier and DNO/DSO to pass-through the price signal on the electricity bill. (iv) A legislative framework to facilitate data sharing and data management and communication among network stakeholders – essentially a relaxation of current privacy legislation as an enabler for new approaches to network management, and potentially to reduce costs to the consumer. This suggests the focus for future network pricing should be on services and functions provided by the grid rather than on the commodity power itself.
[en] Complete text of publication follows. Despite the seemingly ever growing power of computers, inversions of full 3D DC resistivity data are still challenging and time-consuming. Since the inversion processes are based on forward modeling, the speed up of the 3D DC resistivity modeling processes is always an interesting topic. As an iterative solver for discretized large linear equation systems, Multigrid (MG) methods are known for their high convergence rate which is independent to the number of grid nodes. However, when applied to 3D DC resistivity modeling, this attractive property may be affected by high conductivity contrasts. Algebraic Multigrid (AMG) method, based on matrix-dependent operators, can be used to retrieve this problem. The equation of continuity with mixed boundary conditions for 3D DC resistivity modelling is discretized using a standard 7-point finite difference scheme on the finest level with non-equidistant grids. Secondary potential approach is used to remove the singularities on the right-hand-side. Some forward modelling calculations are carried out with an AMG code named AMG1R5, which was made publically available in the mid-1980s. Three underground models, a three-layer model, a vertical contact model and a cubic model, are investigated. The affections of grid sizes and conductivity contrasts to the convergence rate and computational costs are under investigation. Comparing with the ICCG method, a widely used iterative method in 3D DC resistivity modeling, AMG method shows its superior performance just as expected.
[en] The proposal is concerned with an improvement for the supporting elements of the crossbars of a spacer grid for the rod-shaped elements of a nuclear reactor, described in patent no. 2031041. According to the invention the supporting element has got the shape of a cross with one part bended over to form clamps, while the other part may be spot-welded to the flat spring. A zirconium alloy with 2.5% niobium is mentioned as being suited for the crossbar. Flat spring and supporting element consist of a nickel alloy with 13% chromium and 6.5% iron. (UWI) 891 HPI
[de]Der Vorschlag betrifft eine Verbesserung die den Halteelementen der Querstreifen eines Abstandhaltegitters fuer die stabfoermigen Elemente eines Kernreaktors, das im Patent 2031041 beschrieben wird. Erfindungsgemaess ist das Halteelement als Kreuz ausgebildet, wobei der eine Teil zu Klammern umgebogen ist, waehrend der andere mit der Blattfeder punktverschweisst werden kann. Als geeignet fuer den Querstreifen ist eine Zr-Legierung mit 2,5% Nb genannt, Blattfeder und Halteelement bestehen aus einer Nickellegierung mit 13% Chrom und 6,5% Eisen. (UWI)
[en] This memorandum addresses portions of Section 3.5.2 of SRNL (2016) by recommending horizontal and vertical grid resolution for aquifer transport, in preparation for the next E-Area Performance Assessment (WSRC 2008) revision.
[en] Nuclear power combined with smart power grids — the two-way networks that connect producers to consumers and use new technologies to do so — can help countries transition to low carbon electricity sources and ensure reliable, stable and sustainable energy supplies. Many countries are diversifying their mix of low carbon energy sources to help them decarbonize their economies and achieve their climate goals. This has led to a global shift towards renewable energy sources; however, these sources alone are not able to fully and reliably meet demand.
[en] We have conducted on experiment with a purpose to evaluate the performance of grids being used at hospitals in Seoul and adjacent cities of Seoul. The results are as follows; · Reality of the grids use 1. The focused grids were 105 and the parallel grids were 6 among 111 grids subject to experimenting. 2. The grid interspace material was aluminium of 94 and the remains were wood and bakelite. 3. The number of Korean products from five companies was 33 and the one of the foreign products was 34 from companies. · The physical properties have been examined by the notice of Department of Health and Social Affairs. 4. The intensity of secondary radiation was the highest in 5 : 1 grid ratio. 5. The Bucky factor increased with the increase of grid ratio. The selectivity, the grid improvement factor of grids also increased with increase of the grid ratio. However, with 6 : 1 grid ratio those factors were decreased exceptionally. · In measurement of grid density with screen determiners and the beam alignment. 6. In evaluation the results were satisfied within, 20 %. 7. The value of the scale and the value of measurement were within the range of standard deviation, but the value of 103 lines were outranged from the standard deviation with all grid ratio except of 6 : 1 grid ratio
[en] A smart grid refers to a modernization of the electricity system that brings intelligence, reliability, efficiency and optimality to the power grid. To provide an automated and widely distributed energy delivery, the smart grid will be branded by a two-way flow of electricity and information system between energy suppliers and their customers. Thus, the smart grid is a power grid that integrates data communication networks which provide the collected and analysed data at all levels in real time. Therefore, the performance of communication systems is so vital for the success of smart grid. Merit to the ZigBee/IEEE802.15.4std low cost, low power, low data rate, short range, simplicity and free licensed spectrum that makes wireless sensor networks (WSNs) the most suitable wireless technology for smart grid applications. Unfortunately, almost all ZigBee channels overlap with wireless local area network (WLAN) channels, resulting in severe performance degradation due to interference. In order to improve the performance of communication systems, this paper proposes an optimal throughput and self-adaptability of ZigBee/IEEE802.15.4std for smart grid
[en] IEEE As the distribution grid moves toward a tightly-monitored network, it is important to automate the analysis of the enormous amount of data produced by the sensors to increase the operators situational awareness about the system. Here, focusing on Micro-Phasor Measurement Unit (μPMU) data, we propose a hierarchical architecture for monitoring the grid and establish a set of analytics and sensor fusion primitives for the detection of abnormal behavior in the control perimeter. And due to the key role of the μPMU devices in our architecture, a source-constrained optimal μPMU placement is also described that finds the best location of the devices with respect to our rules. The effectiveness of the proposed methods are tested through the synthetic and real μPMU data.
[en] Highlights: • Very high-order spatial discretisations in electrochemical simulations are tested. • Asymmetric 4-to7-point approximations enable to use grids with less than 15 points. • Brute force resolution of the resulting problem is competitive in all cases studied. • Comparison between LU and QR decompositions and sparse matrix methods is performed. • Easy-to-implement, C++ example programs are provided. The use of very high order spatial discretisation in digital simulation of electrochemical experiments is assessed, considering up to asymmetric 8-point approximations for the derivatives. A wide range of conditions are examined, including several mechanisms and electrodes and potential-step and potential-sweep experiments. In all cases it is found that asymmetric multi-point approximations in combination with exponentially expanding grids provides very accurate results and with very reduced number of grid points (<15). Consequently, the direct (‘brute force’) resolution of the finite-difference equation system by standard matrix techniques becomes a competitive and more general alternative to specialised methods like the Thomas algorithm.
[en] Due to the significant environmental impact of power production from fossil fuels and nuclear fission, future energy systems will increasingly rely on distributed and renewable energy sources (RES). The electrical feed-in from photovoltaic (PV) systems and wind energy converters (WEC) varies greatly both over short and long time periods (from minutes to seasons), and (not only) by this effect the supply of electrical power from RES and the demand for electrical power are not per se matching. In addition, with a growing share of generation capacity especially in distribution grids, the top-down paradigm of electricity distribution is gradually replaced by a bottom-up power supply. This altogether leads to new problems regarding the safe and reliable operation of power grids. In order to address these challenges, the notion of Smart Grids has been introduced. The inherent flexibilities, i.e. the set of feasible power schedules, of distributed power units have to be controlled in order to support demand–supply matching as well as stable grid operation. Controllable power units are e.g. combined heat and power plants, power storage systems such as batteries, and flexible power consumers such as heat pumps. By controlling the flexibilities of these units we are particularly able to optimize the local utilization of RES feed-in in a given power grid by integrating both supply and demand management measures with special respect to the electrical infrastructure. In this context, decentralized systems, autonomous agents and the concept of self-organizing systems will become key elements of the ICT based control of power units. In this contribution, we first show how a decentralized load management system for battery charging/discharging of electrical vehicles (EVs) can increase the locally used share of supply from PV systems in a low voltage grid. For a reliable demand side management of large sets of appliances, dynamic clustering of these appliances into uniformly controlled appliance sets is necessary. We introduce a method for self-organized clustering for this purpose and show how control of such clusters can affect load peaks in distribution grids. Subsequently, we give a short overview on how we are going to expand the idea of self-organized clusters of units into creating a virtual control center for dynamic virtual power plants (DVPP) offering products at a power market. For an efficient organization of DVPPs, the flexibilities of units have to be represented in a compact and easy to use manner. We give an introduction how the problem of representing a set of possibly 10"1"0"0 feasible schedules can be solved by a machine-learning approach. In summary, this article provides an overall impression how we use agent based control techniques and methods of self-organization to support the further integration of distributed and renewable energy sources into power grids and energy markets. - Highlights: • Distributed load management for electrical vehicles supports local supply from PV. • Appliances can self-organize into so called virtual appliances for load control. • Dynamic VPPs can be controlled by extensively decentralized control centers. • Flexibilities of units can efficiently be represented by support-vector descriptions