06 Electricalpower generation and utilization (scientific, technical) This paper presents a formulation of the minimum nitrogen oxide (No,) emission dispatch that uses demand prioritization and load curtailment policy to limit the power system load during emergencies. The effects of these control strategies on the system No, emission and the system thermal fuel costs are investigated during power system emergencies. A non-linear programming approach is used to determine the optimal values of system No, emission, associated fuel cost and active power loss during emergencies. Different state of emergencies defined by demand prioritization and load curtailment are considered and results obtained for IEEE 30-bus test system.
Fluoroethylene carbonate electrolyte and its use in lithium ion batterles with graphite anodes
00101375
McMillan, R. et nl. J. Power Sources, 1999, 81-82, (20-26), The electrolyte decomposition during the first lithiation of graphite is reduced to 85 mA h/g in an electrolyte, containing equal volumes of fluoroethylene carbonate (Fluoro-EC) and of a co-solvent propylene carbonate (PC). The volume fraction of Fluoro-EC can be further reduced to 0.05 in a tri-solvent system with a co-solvent containing equal volumes of ethylene carbonate (EC) and PC. A lithium ion cell containing Fluoro-EC PC and EC shows a long cycle life. The capacity decreases by 37% from the initial value in over 200 cycles. Cell current efficiency is 100%, thus solving the poor cell current efficiency when chloroethylene carbonate (ChloroEC) is used in place of Fluoro-EC. 00/01376 Fuel cell power trains for road traffic Hiihlein, B. J. sf Power Sources, 1999, 84, (2). 203-213. Legal regulations, especially the low emission vehicle (LEV) laws in California, are the driving forces for more intensive technological developments with respect to a global automobile market. In the future, high efficient vehicles at very low emission levels will include low temperature fuel cell systems (e.g., polymer electrolyte fuel cell (PEFC)) as units of hydrogen-, methanol- or gasoline-based electric power trains. In the case of methanol or gasoline/diesel, hydrogen has to be produced onboard using heated steam or partial oxidation reformers as well as catalytic burners and gas cleaning units. Methanol could also be used for direct electricity generation inside the fuel cell (direct methanol fuel cell (DMFC)). The development potentials and the results achieved so far for these concepts differ extremely. Based on the experience gained so far, the goals for the next few years include cost and weight reductions as well as optimizations in terms of the energy management of power trains with PEFC systems. At the same time, questions of fuel specification, fuel cycle management, materials balances and environmental assessment will have to be discussed more intensively. On the basis of process engineering analyses for net electricity generation in PEFC-powered power trains as well as on assumptions for both electric power trains and vehicle configurations, overall balances have been carried out. They will lead not only to specific energy demand data and specific emission levels (COz, CO, VOC, NO,) for the vehicle but will also present data of its full fuel cycle (FFC) in comparison to those of FFCs including internal combustion engines (ICE) after the year 2005. Depending on the development status (today or in 2010) and the FFC benchmark results, the advantages of balances results of FFC with PEFC vehicles are small in terms of specific energy demand and CO2 emissions, but very high with respect to local emission levels. 00/01377 Gasoline fuel cell systems Dotter, A. and Lamm, A. J. of Power Sources, 1999, 84, (2), 194-200. For different types of hydrocarbon fuel reformer concepts, thermodynamic equilibrium calculations were conducted. These simulations allow estimation of the potential energy efficiency of these reformers and thus help to choose the right technology before further development work starts. According to the simulation results, autothermal-reforming can yield higher energy efficiencies than partial oxidation. 00101376 High capacity carbon anode for Li-ion battery. A theoretical explanation Tokumitsu, K. et al. Crrrhon. 1999, 37. (IO), 1599-1605. Mesocarbon microbeads (MCMBs) heat-treated below 1000°C have discharge higher than the theoretical value of graphite, 372 Ah kg-‘. The high capacity has been explained on the basis of cavity model, which lithium species are not only intercalated in carbon layers but also doped in cavities, derived from structural parameters of MCMB. The theoretical values corresponding to the intercalation capacity and total capacity were in good agreement with each capacity. The cavity size and distribution was characterized based on the Fourier analysis of 002 diffraction profiles on a XRD. This analysis revealed that the high capacity MCMBs have cavities with the size of OS-l.5 nm.
00101379 High power metal hydride bipolar battery Wiesener, K. J. of Power Sources. Nickel/metal hydiide batteries in a an application as a power storage The paper deals with some aspects common vessel design.
1999. 84. (2). 248-258. bipolar design offer some advantages for system for electric and hybrid vehicles. of combining a number of sub-cells in a
00101360 High-rate, valve-regulated lead-acid batteriessuitable for hybrid electric vehicles? Moseley, P. T. J. of Power Sources, 1999, 84, (2). 237-242.
The possibility of replacing, with electric drive systems, at least some of the internal-combustion engines currently employed in road vehicles is being actively pursued by all the world’s major automobile manufacturing companies. Minimum on-road emissions would be achieved by the adoption of pure electric vehicles, but the somewhat limited range available between charges of the batteries has led to a serious evaluation of hybrid electric vehicles as an acceptable compromise. In hybrids, a small internalcombustion engine, operated at high efficiency, will consume less fuel and produce less emissions than would a regular internal-combustion engine, and will allow considerable range extension over the pure electric vehicle. Eventually, an electric system, which employs a fuel cell, may become affordable. It is likely that all three system-the pure electric, the hybrid electric, and the fuel cell system-will require battery support, particularly to provide boost power for acceleration and hill climbing. Although more expensive battery systems are being vigorously developed in pursuit of greater range per charge, the benchmark against which these systems are compared remains the valve-regulated lead-acid (VRLA) battery.
00/01361 Hybrid electric vehicles and electrochemical storage systems-a technology push-pull couple Gutmann, G. J. of Powr Sorums. 1999. 84, (2). 275-279. In the advance of fuel cell electric vehicles (EV), hybrid electric vehicles (HEV) can contribute to reduced emissions and energy consumption of personal cars as a short term solution. Trade-offs reveal better emission control for series hybrid vehicles, while parallel hybrid vehicles with different drive trains may significantly reduce fuel consumption as well. At present, costs and marketing considerations favour parallel hybrid vehicles making use of small, high power batteries. With ultra high power density cells in development, exceeding 1 kW/kg, adapting a technology closely related to consumer cell production could provide high power batteries. Energy consumption and emissions may benefit from regenerative braking and smoothing of the internal combustion engine (ICE) response as well, with limited additional battery weight. High power Supercapacitors may assist the achievement of this goal. Problems to be solved in practice comprise battery management to assure equilibration of individual cell state-of-charge for long battery life without maintenance, and efficient strategies for low energy consumption.
integrating three-phase load flow and short-circuit current calculation for a low voltage system
00101362
Teo, C. Y. and He, B. G. Electric Powr Sysrems Reseurch, 2000. 53. (2). 123-132. This paper summaries a dedicated approach to solve three-phase load flow and calculate unbalanced short-circuit current simultaneously for low voltage systems without using the conventional symmetrical components. As the unbalanced load and the neutral and shock voltages have to be modelled, the network equations including the representation of the neutral and grounding conductors are formulated entirely in phase coordinates. Test results demonstrate the ability in modelling the untransposed cable parameters and the influence of the unbalanced load currents. More accurate results can thus be obtained as compared with other methods of calculation. Many interesting phenomena such as unbalanced load flow, different voltages appearing at various sections of the neutral and grounding conductors, effects of the disconnection of the source earthing, and any open-circuit fault can all be simulated. 00/01363 Lithium batteries: a new tool in solid state chemistry Delmas, C. Int. J. Inorganic, Materids. 1999, 1. (I). I I-I 9. Lithium batteries are being intensively studied owing to the considerable challenge they represent for applications. From a fundamental point of view, the shape of the charge/discharge curves gives information on all the structural and physical properties modifications which occur during the intercalationldeintercalation process. Moreover the electrochemical reaction is a way of synthesizing metastable materials which cannot be obtained by classical methods. The ease of monitoring very accurately either the cell voltage (oxidation state of the material) or the number of electrons transferred (lithium content in the material) makes lithium batteries a new and very convenient tool for the solid state chemist. Typical examples are presented.
00/01364 Manufacture of secondary battery electrodes, the electrodes, and batteries comprising the electrodes Watanabe, K. Jpn. Kokai Tokkyo Koho JP I1 31,501 [99 31,501] (Cl. HOlM4/04), 2 Feb 1999, Appl. 971184.813, 10 Jul 1997. 6. (In Japanese) Amorphous carbonaceous materials are heated in an inert atmosphere or in a vacuum for the removal of their hydrophilic functional groups before they can be formed into electrodes. The carbonaceous materials may be prepared from petroleum pitch, coal pitch, or organic polymers, such as phenolic resins and aromatic polyamides. The obtained electrodes, which de-and absorb alkali metal ion, and batteries comprising the electrodes arc also claimed. It is possible to recover the decrease in discharge capacity when electrodes are stored in air.
00/01365 Medium voltage SF6 circuit-breaker arc model application Pinto, L. C. and Zanetta, (I), 67-71.
L. C. Electric
Power S_EVIC~.FRe.senrr~h. 2000. 53.
Fuel and Energy Abstracts
May 2000
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