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02858 Tuning the fuzzy damping controller for UPFC through genetic algorithm with comparison to the gradient descent training
17 Energy (supplies, policy, economics, forecasts) following the steps of Lyapunov's second method (also termed as the direct method) of stability of motion. The thermodynamic Lyapunov function; L,, used herein is the excess rate of entropy production in the thermodynamic perturbation space, which thereby inherits the dictates of the second law of thermodynamics. This Lyapunov function is not the same as the excess entropy rate that one encounters in thermodynamic (irreversible) literature. The model chemical conversions studied in this presentation are A + B u~X and A + B ~- u~X. For the sake of simplicity, the thermal effects of chemical reactions have been considered as not adding to the perturbation as the main aim was to demonstrate how one should use systematicaIly the proposed thermodynamic Lyapunov function following the steps of Lyapuuov's second method of stability of motion. The domains of thermodynamic stability under the constantly acting small disturbances, thermodynamic asymptotic stability and thermodynamic instability in these model systems get established.
05/02857 Transport properties of non-spherical nanoparticles studied by Brownian dynamics: theory and numerical simulations Naess, S. N. and Elgsaeter, A. Energy, 2005, 30, (6), 831 844. The authors have succeeded in extending the Brownian dynamics analyses to systems consisting of non-spherical nanoparticles interconnected by conservative forces or holonomic constraints. The formal theory takes fully into account both nanoparticle size and surface topography. The theory also incorporates stretching, bending and torsional stiffness between nearest neighbour subunits, excluded volume effects, external force fields, fluid flow and fluid-dynamic interactions. The generalized conformation-space diffusion equations are rigorously derived from kinetic theory. The equivalent stochastic differential equations are used as the basis for development of the associated Brownian dynamics algorithms. These algorithms may be employed to carry out equilibrium as well as non-equilibrium simulations of the conformational dynamics and transport properties for a wide class of nanoparticle systems embedded in viscous fluids. To test the validity of the theory and the numerical algorithms, the authors present the results from a simulation example.
05•02858 Tuning the fuzzy damping controller for UPFC through genetic algorithm with comparison to the gradient descent training Mok, T. K. et al. International Journal of Electrical Power & Energy Systems, 2005, 27, (4), 275-283. The unified power flow controller (UPFC) is the most versatile device in the flexible ac transmission systems (FACTS) that can provide superior power flow and voltage control through its main control. It can also improve power system dynamic performance through its supplementary control. In this paper, a fuzzy supplementary controller is designed for the UPFC to damp tie line power oscillation in the interconnected power systems. The parameters of the fuzzy damping controller (FDC) are optimized using the gradient descent training method and the genetic algorithm, respectively. The UPFC power frequency model, its main and supplementary control block diagrams and the formulation for the FDC parameter optimization are presented. Time simulation on a multi-machine inter-connected power system shows that the two optimization methods converge very well and yield very close FDC parameters and the designed FDC performs well in damping the tie line power oscillation under large disturbances. Computer simulation results also show that the FDC has better robustness under different system operation conditions than its conventional counterpart.
05•02859 Vented gaseous deflagrations. Modelling of hinged inertial vent covers Molkov, V. V. et al. Yournal of Hazardous Materials', 2004, ii6, (1-2), 1 10.
The model of explosion pressure build up in enclosures with inertial vent covers and the CINDY code implementing the model are validated against earlier experiments in a 50 m 3 vessel with a pair of ceiling-mounted upwards-opening hinged doors in a 'butterfly' configuration with surface densities of 73 and 124 kg/m 2 under conditions of initially quiescent and turbulent mixtures. The model and the code are further validated against another experiment in a 33.5 m 3 room-like enclosure with a pair of wall-mounted rectangular doors, in a parallel configuration, each hinged at its bottom edge with a surface density of 23.1 kg/m 2 and initially quiescent mixture. A formula for the torque acting upon a rotating venting door is derived under conditions of vent cover jet formation. The vent cover jet effect decreases the torque three times compared to an elementary approach valid at the start of vent cover movement. It is demonstrated that, similar to translating vent covers, the vent cover jet effect is crucial for prediction of interdependent vent cover displacement in time and pressure transients.
414 Fuel and Energy Abstracts
November 2005
17
ENERGY
Supplies, policy, economics, forecasts 05/02860 Accuracy of past projections of US energy consumption O'Neill, B. C. and Desai, M. Energy Policy, 2005, 33, (8), 979-993. Energy forecasts play a key role in development of energy and environmental policy. Evaluations of the accuracy of past projections can provide insight into the uncertainty that may be associated with current forecasts. They can also be used to identify sources of inaccuracies, and potentially lead to improvements in projections over time. Here the authors assess the accuracy of projections of US energy consumption produced by the Energy Information Administration over the period 1982-2000. It was found that energy consumption projections have tended to underestimate future consumption. Projections 10-13 years into the future have had an average error of about 4%, and about half that for shorter time horizons. These errors mask much larger, offsetting errors in the projection of GDP and energy intensity (EI). GDP projections have consistently been too high, and EI projection consistently too low, by more than 15% for projections of 10 years or more. Further work on the source of these sizable inaccuracies should be a high priority. Finally, no evidence was found of improvement in projections of consumption, GDP, or EI since 1982.
05/02861 Determination of the appropriate energy policy for Turkey Ulutas, B. H. Energy, 2005, 30, (7), 1146-116l. Energy is an inevitable necessity for h u m a n beings. But the energy source is predicted to be scarce in the coming years as a result of population growth. Therefore people prefer energy sources that are renewable, clean and cost effective. Unfortunately there is not a sole energy source to meet these demands. Determination of the appropriate energy policy problem with interactive criteria and alternatives can be viewed as a multiple criteria decision making (MCDM) problem within the context of the long range and strategic process. The analytic network process (ANP), one of MCDM methods, deals with the dependency and feedback that the problem has. The goal of this paper is to apply the ANP model to evaluate the alternative energy sources for the country. Finally when the results are discussed, it is apparent that the model can produce reasonable and applicable solutions for the case.
05/02862 Directional distance functions and environmental regulation Picazo-Tadeo, A. J. et al. Resource and Energy Economics, 2005, 27, (2), 131-142. This paper uses directional technology distance functions to evaluate the impact of environmental regulations on firms' performance. Following an earlier study, the authors construct an index that measures opportunity costs for individual firms arising from regulations that prevent free disposal of wastes. The methodology is applied to a sample of Spanish producers of ceramic pavements. It is assumed that firms maximize desirable output simultaneously reducing inputs, with no change in the production of bad outputs. The results show that when firms face environmental rules preventing free disposal of bads, their potential to increase desirable output by behaving efficiently is largely affected. It was also found that large firms show smaller regulation costs.
05•02863 Effect of financial and fiscal incentives on the effective capital cost of solar energy technologies to the user Chandrasekar, B. and Kandpal, T. C. Solar Energy, 2005, 78, (2), 147156. Development and dissemination of solar energy technologies in India has been aided by a variety of policy and support measures. One of the promotional measures is the provision of financial and fiscal incentives such as capital subsidy, low interest loan and accelerated depreciation related income tax benefits to the users on the purchase of solar energy technologies. In this study an attempt has been made to determine the effective capital cost of solar energy technologies to the user with the provision of financial and/or fiscal incentives. Results of exemplifying calculations for a domestic and an industrial solar water heating system, a solar home lighting system and a solar drying system have been presented and discussed.
05/02857 Transport properties of non-spherical nanoparticles studied by Brownian dynamics: theory and numerical simulations Naess, S. N. and Elgsaeter, A. Energy, 2005, 30, (6), 831 844. The authors have succeeded in extending the Brownian dynamics analyses to systems consisting of non-spherical nanoparticles interconnected by conservative forces or holonomic constraints. The formal theory takes fully into account both nanoparticle size and surface topography. The theory also incorporates stretching, bending and torsional stiffness between nearest neighbour subunits, excluded volume effects, external force fields, fluid flow and fluid-dynamic interactions. The generalized conformation-space diffusion equations are rigorously derived from kinetic theory. The equivalent stochastic differential equations are used as the basis for development of the associated Brownian dynamics algorithms. These algorithms may be employed to carry out equilibrium as well as non-equilibrium simulations of the conformational dynamics and transport properties for a wide class of nanoparticle systems embedded in viscous fluids. To test the validity of the theory and the numerical algorithms, the authors present the results from a simulation example.
05•02858 Tuning the fuzzy damping controller for UPFC through genetic algorithm with comparison to the gradient descent training Mok, T. K. et al. International Journal of Electrical Power & Energy Systems, 2005, 27, (4), 275-283. The unified power flow controller (UPFC) is the most versatile device in the flexible ac transmission systems (FACTS) that can provide superior power flow and voltage control through its main control. It can also improve power system dynamic performance through its supplementary control. In this paper, a fuzzy supplementary controller is designed for the UPFC to damp tie line power oscillation in the interconnected power systems. The parameters of the fuzzy damping controller (FDC) are optimized using the gradient descent training method and the genetic algorithm, respectively. The UPFC power frequency model, its main and supplementary control block diagrams and the formulation for the FDC parameter optimization are presented. Time simulation on a multi-machine inter-connected power system shows that the two optimization methods converge very well and yield very close FDC parameters and the designed FDC performs well in damping the tie line power oscillation under large disturbances. Computer simulation results also show that the FDC has better robustness under different system operation conditions than its conventional counterpart.
05•02859 Vented gaseous deflagrations. Modelling of hinged inertial vent covers Molkov, V. V. et al. Yournal of Hazardous Materials', 2004, ii6, (1-2), 1 10.
The model of explosion pressure build up in enclosures with inertial vent covers and the CINDY code implementing the model are validated against earlier experiments in a 50 m 3 vessel with a pair of ceiling-mounted upwards-opening hinged doors in a 'butterfly' configuration with surface densities of 73 and 124 kg/m 2 under conditions of initially quiescent and turbulent mixtures. The model and the code are further validated against another experiment in a 33.5 m 3 room-like enclosure with a pair of wall-mounted rectangular doors, in a parallel configuration, each hinged at its bottom edge with a surface density of 23.1 kg/m 2 and initially quiescent mixture. A formula for the torque acting upon a rotating venting door is derived under conditions of vent cover jet formation. The vent cover jet effect decreases the torque three times compared to an elementary approach valid at the start of vent cover movement. It is demonstrated that, similar to translating vent covers, the vent cover jet effect is crucial for prediction of interdependent vent cover displacement in time and pressure transients.
414 Fuel and Energy Abstracts
November 2005
17
ENERGY
Supplies, policy, economics, forecasts 05/02860 Accuracy of past projections of US energy consumption O'Neill, B. C. and Desai, M. Energy Policy, 2005, 33, (8), 979-993. Energy forecasts play a key role in development of energy and environmental policy. Evaluations of the accuracy of past projections can provide insight into the uncertainty that may be associated with current forecasts. They can also be used to identify sources of inaccuracies, and potentially lead to improvements in projections over time. Here the authors assess the accuracy of projections of US energy consumption produced by the Energy Information Administration over the period 1982-2000. It was found that energy consumption projections have tended to underestimate future consumption. Projections 10-13 years into the future have had an average error of about 4%, and about half that for shorter time horizons. These errors mask much larger, offsetting errors in the projection of GDP and energy intensity (EI). GDP projections have consistently been too high, and EI projection consistently too low, by more than 15% for projections of 10 years or more. Further work on the source of these sizable inaccuracies should be a high priority. Finally, no evidence was found of improvement in projections of consumption, GDP, or EI since 1982.
05/02861 Determination of the appropriate energy policy for Turkey Ulutas, B. H. Energy, 2005, 30, (7), 1146-116l. Energy is an inevitable necessity for h u m a n beings. But the energy source is predicted to be scarce in the coming years as a result of population growth. Therefore people prefer energy sources that are renewable, clean and cost effective. Unfortunately there is not a sole energy source to meet these demands. Determination of the appropriate energy policy problem with interactive criteria and alternatives can be viewed as a multiple criteria decision making (MCDM) problem within the context of the long range and strategic process. The analytic network process (ANP), one of MCDM methods, deals with the dependency and feedback that the problem has. The goal of this paper is to apply the ANP model to evaluate the alternative energy sources for the country. Finally when the results are discussed, it is apparent that the model can produce reasonable and applicable solutions for the case.
05/02862 Directional distance functions and environmental regulation Picazo-Tadeo, A. J. et al. Resource and Energy Economics, 2005, 27, (2), 131-142. This paper uses directional technology distance functions to evaluate the impact of environmental regulations on firms' performance. Following an earlier study, the authors construct an index that measures opportunity costs for individual firms arising from regulations that prevent free disposal of wastes. The methodology is applied to a sample of Spanish producers of ceramic pavements. It is assumed that firms maximize desirable output simultaneously reducing inputs, with no change in the production of bad outputs. The results show that when firms face environmental rules preventing free disposal of bads, their potential to increase desirable output by behaving efficiently is largely affected. It was also found that large firms show smaller regulation costs.
05•02863 Effect of financial and fiscal incentives on the effective capital cost of solar energy technologies to the user Chandrasekar, B. and Kandpal, T. C. Solar Energy, 2005, 78, (2), 147156. Development and dissemination of solar energy technologies in India has been aided by a variety of policy and support measures. One of the promotional measures is the provision of financial and fiscal incentives such as capital subsidy, low interest loan and accelerated depreciation related income tax benefits to the users on the purchase of solar energy technologies. In this study an attempt has been made to determine the effective capital cost of solar energy technologies to the user with the provision of financial and/or fiscal incentives. Results of exemplifying calculations for a domestic and an industrial solar water heating system, a solar home lighting system and a solar drying system have been presented and discussed.