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Sample records for analysis increases power

  1. Filtering for increased power for microarray data analysis

    Directory of Open Access Journals (Sweden)

    Hess Ann M

    2009-01-01

    Full Text Available Abstract Background Due to the large number of hypothesis tests performed during the process of routine analysis of microarray data, a multiple testing adjustment is certainly warranted. However, when the number of tests is very large and the proportion of differentially expressed genes is relatively low, the use of a multiple testing adjustment can result in very low power to detect those genes which are truly differentially expressed. Filtering allows for a reduction in the number of tests and a corresponding increase in power. Common filtering methods include filtering by variance, average signal or MAS detection call (for Affymetrix arrays. We study the effects of filtering in combination with the Benjamini-Hochberg method for false discovery rate control and q-value for false discovery rate estimation. Results Three case studies are used to compare three different filtering methods in combination with the two false discovery rate methods and three different preprocessing methods. For the case studies considered, filtering by detection call and variance (on the original scale consistently led to an increase in the number of differentially expressed genes identified. On the other hand, filtering by variance on the log2 scale had a detrimental effect when paired with MAS5 or PLIER preprocessing methods, even when the testing was done on the log2 scale. A simulation study was done to further examine the effect of filtering by variance. We find that filtering by variance leads to higher power, often with a decrease in false discovery rate, when paired with either of the false discovery rate methods considered. This holds regardless of the proportion of genes which are differentially expressed or whether we assume dependence or independence among genes. Conclusion The case studies show that both detection call and variance filtering are viable methods of filtering which can increase the number of differentially expressed genes identified. The

  2. Analysis of power and frequency control requirements in view of increased decentralized production and market liberalization

    NARCIS (Netherlands)

    Roffel, B; de Boer, WW

    2003-01-01

    This paper presents a systematic approach of the analysis of the minimum control requirements that are imposed on power producing units in the Netherlands, especially in the case when decentralized production increases. Also some effects of the liberalization on the control behavior are analyzed. Fi

  3. Economic Analysis of Cikaso Mini Hydro Power Plant as a CDM Project for Increasing IRR

    Directory of Open Access Journals (Sweden)

    Irhan Febijanto

    2013-12-01

    Full Text Available Renewable energy fueled power generations are few developed by private sector in Indonesia. High-cost investment and low electricity selling price to PT PLN as a single buyer is main barriers for private sector to involve in the development of renewable energy fueled power generations. In this project, the economic feasibility of Mini Hydro Power Plant of Cikaso with capacity of 5.3 MW, located at Sukabumi Regency, West Java province was assessed. This project utilized revenue generated from carbon market to increase the economic feasibility. Procedure to register the project to United Nation for Climate Change Convention (UNFCCC as a Clean Development Mechanism project was explained in detail. Approved Consolidation Methodology (ACM 0002 Version 12.3.0 was used to calculate grid emission factor in Jawa-Bali-Madura the grid electricity system. It was calculated that the grid emission factor is 0.833 (t-CO2/MWh, and the carbon emission reduction generated for this project is 21,982 ton/year. From the analysis result, it can be proven that the additional revenue from carbon credit could increase the project IRR from 10.28% to 13.52%.

  4. UV-visible microscope spectrophotometric polarization and dichroism with increased discrimination power in forensic analysis

    Science.gov (United States)

    Purcell, Dale Kevin

    merit investigated included: 1) wavelength accuracy, 2) wavelength precision, 3) wavelength resolution stability, 4) photometric accuracy, 5) photometric precision, 6) photometric linearity, 7) photometric noise, and 8) short-term baseline stability. In addition, intrinsic instrument polarization effects were investigated to determine the impact of these properties on spectral interpretation and data quality. Finally, a set of recommendations were developed which describe instrument performance characteristics for microscope and spectrometer features and functions, and specific instrument parameters that must be controlled in order to acquire high quality data from an ultraviolet-visible forensic microscope spectrophotometer system for increased discrimination power.

  5. Alternative analysis to increase the power in combined-cycle power plants; Analisis de alternativas para el incremento de potencia en plantas termoelectricas de Ciclo Combinado

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco Cruz, Hector; Arriola Medellin, Alejandro M. [Gerencia de Procesos Termicos, Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: hpacheco@iie.org.mx; aarriola@iie.org.mx

    2010-11-15

    The electricity industry traditionally had two thermodynamic cycles for power generation: conventional steam turbine (Rankine cycle) used to supply a base load during the day, and gas turbines (Brayton cycle), for its speed response, normally used to cover peak loads. However, to provide variable peak loads, the gas turbine, as a volumetric machine is affected by the change in air density by changing the combustion temperature. This paper shows the scheme of integration of both systems, that it's known as combined cycle and the different options that would have these power plants, to maintain or increase their power in variable ambient conditions. It analyzes different options, such as: 1. Supplementary fire in the stove. 2. Air cooling intake in the gas turbine (evaporation system or mechanical system). 3. Steam injection in the combustion chamber. [Spanish] La industria electrica tradicionalmente a contado con dos ciclos termodinamicos para generacion electrica: las turbinas convencionales de vapor (ciclo de Rankine) se utilizan para suministrar una carga base durante el dia, y las turbinas de gas (ciclo de Brayton), por su rapidez de respuesta, se utilizan normalmente para cubrir las cargas pico. Sin embargo, para suministrar las cargas variables pico, la turbina a gas, por ser una maquina volumetrica, se ve afectada por el cambio de la densidad del aire de combustion al cambiar la temperatura ambiente. En este trabajo se muestra el esquema de integracion de ambos sistemas, en lo que se conoce como ciclo combinado y las diferentes opciones que tendrian estas plantas de generacion electrica para mantener o incrementar su potencia en condiciones ambiente variable. Para ello se analizan diferentes opciones, tales como: 1.- Combustion suplementaria en el recuperador de calor. 2.- Enfriamiento del aire de admision a la turbina de gas (mediante un sistema de evaporacion o mediante un sistema mecanico). 3.- Inyeccion de vapor a la camara de combustion. Palabras

  6. System-wide emissions implications of increased wind power penetration.

    Science.gov (United States)

    Valentino, Lauren; Valenzuela, Viviana; Botterud, Audun; Zhou, Zhi; Conzelmann, Guenter

    2012-04-03

    This paper discusses the environmental effects of incorporating wind energy into the electric power system. We present a detailed emissions analysis based on comprehensive modeling of power system operations with unit commitment and economic dispatch for different wind penetration levels. First, by minimizing cost, the unit commitment model decides which thermal power plants will be utilized based on a wind power forecast, and then, the economic dispatch model dictates the level of production for each unit as a function of the realized wind power generation. Finally, knowing the power production from each power plant, the emissions are calculated. The emissions model incorporates the effects of both cycling and start-ups of thermal power plants in analyzing emissions from an electric power system with increasing levels of wind power. Our results for the power system in the state of Illinois show significant emissions effects from increased cycling and particularly start-ups of thermal power plants. However, we conclude that as the wind power penetration increases, pollutant emissions decrease overall due to the replacement of fossil fuels.

  7. Analysis of Wireless Power Transmission

    OpenAIRE

    2013-01-01

    The advent of various wireless technologies have revolutionized the communication infrastructure and consequently changed the entire world into a global village. Use of wireless technology has also been made for transmission of electric power wirelessly. It increases the portability of power systems and integrates the communication technologies and electric power to the same platform. This paper presents a comprehensive review and detailed analysis of various techniques used for wireless powe...

  8. Wind Power Ramping Product for Increasing Power System Flexibility

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Mingjian; Zhang, Jie; Wu, Hongyu; Hodge, Bri-Mathias; Ke, Deping; Sun, Yuanzhang

    2016-05-05

    With increasing penetrations of wind power, system operators are concerned about a potential lack of system flexibility and ramping capacity in real-time dispatch stages. In this paper, a modified dispatch formulation is proposed considering the wind power ramping product (WPRP). A swinging door algorithm (SDA) and dynamic programming are combined and used to detect WPRPs in the next scheduling periods. The detected WPRPs are included in the unit commitment (UC) formulation considering ramping capacity limits, active power limits, and flexible ramping requirements. The modified formulation is solved by mixed integer linear programming. Numerical simulations on a modified PJM 5-bus System show the effectiveness of the model considering WPRP, which not only reduces the production cost but also does not affect the generation schedules of thermal units.

  9. Combined analysis of data from two granddaughter designs: A simple strategy for QTL confirmation and increasing experimental power in dairy cattle

    Directory of Open Access Journals (Sweden)

    Blümel Jürgen

    2003-05-01

    Full Text Available Abstract A joint analysis of five paternal half-sib Holstein families that were part of two different granddaughter designs (ADR- or Inra-design was carried out for five milk production traits and somatic cell score in order to conduct a QTL confirmation study and to increase the experimental power. Data were exchanged in a coded and standardised form. The combined data set (JOINT-design consisted of on average 231 sires per grandsire. Genetic maps were calculated for 133 markers distributed over nine chromosomes. QTL analyses were performed separately for each design and each trait. The results revealed QTL for milk production on chromosome 14, for milk yield on chromosome 5, and for fat content on chromosome 19 in both the ADR- and the Inra-design (confirmed within this study. Some QTL could only be mapped in either the ADR- or in the Inra-design (not confirmed within this study. Additional QTL previously undetected in the single designs were mapped in the JOINT-design for fat yield (chromosome 19 and 26, protein yield (chromosome 26, protein content (chromosome 5, and somatic cell score (chromosome 2 and 19 with genomewide significance. This study demonstrated the potential benefits of a combined analysis of data from different granddaughter designs.

  10. Soil Parameter Mapping and Ad Hoc Power Analysis to Increase Blocking Efficiency Prior to Establishing a Long-Term Field Experiment

    Directory of Open Access Journals (Sweden)

    Doug Collins

    2015-01-01

    Full Text Available The spatial heterogeneity of soil and weed populations poses a challenge to researchers. Unlike aboveground variability, below-ground variability is more difficult to discern without a strategic soil sampling pattern. While blocking is commonly used to control environmental variation, this strategy is rarely informed by data about current soil conditions. Fifty georeferenced sites were located in a 0.65 ha area prior to establishing a long-term field experiment. Soil organic matter (OM and weed seed bank populations were analyzed at each site and the spatial structure was modeled with semivariograms and interpolated with kriging to map the surface. These maps were used to formulate three strategic blocking patterns and the efficiency of each pattern was compared to a completely randomized design and a west to east model not informed by soil variability. Compared to OM, weeds were more variable across the landscape and had a shorter range of autocorrelation, and models to increase blocking efficiency resulted in less increase in power. Weeds and OM were not correlated, so no model examined improved power equally for both parameters. Compared to the west to east blocking pattern, the final blocking pattern chosen resulted in a 7-fold increase in power for OM and a 36% increase in power for weeds.

  11. Valka to increase biofuel power capacity

    Index Scriptorium Estoniae

    2011-01-01

    Eesti Energia omandas enamusosaluse Valka soojusettevõttes Host Energo. Eesti Energiale kuulub nüüd 90% ettevõttest ja linnale 10%. Ettevõte uus nimi on Enefit Heat&Power Valka ja viimane rajab aastaks 2012 Valka uue biokütusel koostootmisjaama

  12. Power electronics reliability analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mark A.; Atcitty, Stanley

    2009-12-01

    This report provides the DOE and industry with a general process for analyzing power electronics reliability. The analysis can help with understanding the main causes of failures, downtime, and cost and how to reduce them. One approach is to collect field maintenance data and use it directly to calculate reliability metrics related to each cause. Another approach is to model the functional structure of the equipment using a fault tree to derive system reliability from component reliability. Analysis of a fictitious device demonstrates the latter process. Optimization can use the resulting baseline model to decide how to improve reliability and/or lower costs. It is recommended that both electric utilities and equipment manufacturers make provisions to collect and share data in order to lay the groundwork for improving reliability into the future. Reliability analysis helps guide reliability improvements in hardware and software technology including condition monitoring and prognostics and health management.

  13. Investigating power control in autonomous power systems with increasing wind power penetration

    Energy Technology Data Exchange (ETDEWEB)

    Margaris, Ioannis D. [National Technical Univ. of Athens (Greece). Electric Energy Systems Lab.; Hansen, Anca D.; Sorensen, Poul [Risoe National Laboratory, Roskilde (Denmark). Wind Energy Dept.; Hatziargyriou, Nikos D. [National Technical Univ. of Athens (Greece). Electric Energy Systems Lab.; Public Power Corporation S.A., Athens (Greece)

    2009-07-01

    Increasing levels of wind penetration in autonomous power systems has set intensively high standards with respect to wind turbine technology during the last years. Special features of non-interconnected power systems make security issues rather critical, as the operation of large wind farms like conventional power plants is becoming a necessity. This paper includes the study case of Rhodos island, in Greece, where rapidly increasing wind penetration has started to impose serious security issues for the immediate future. The scenarios studied here correspond to reference year of study 2012 and include wind farms with three different wind turbine technologies - namely Doubly Fed Induction Generator (DFIG), Permanent Magnet Synchronous Generator (PMSG) and Active Stall Induction Generator (ASIG) based wind turbines. Aggregated models of the wind farms are being used and results for different load cases are being analyzed and discussed. The ability of wind farms to assist in some of the power system control services traditionally carried out by conventional synchronous generation is being investigated and discussed. The power grid of the island, including speed governors and automatic voltage regulators, is simulated in the dedicated power system simulation program Power Factory from DIgSILENT. (orig.)

  14. Dexamphetamine reduces auditory P3 delta power and phase-locking while increasing gamma power.

    Science.gov (United States)

    Albrecht, Matthew A; Price, Greg; Lee, Joseph; Iyyalol, Rajan; Martin-Iverson, Mathew T

    2012-10-01

    Auditory P3 amplitude reduction is one of the most robust and replicated findings in schizophrenia. Recent evidence suggests that these reductions are due to reductions in both power and phase-locking at delta and theta frequencies. We have previously shown that the auditory, but not visual, P3 is reduced in healthy participants given the catecholamine releasing agent dexamphetamine. Our aim was to determine whether the auditory P3 amplitude reduction induced by dexamphetamine has similar power and phase locking characteristics to that seen in schizophrenia. Forty-four healthy participants were given 0.45 mg/kg dexamphetamine and placebo, in a double-blinded, placebo-controlled, cross-over design. The task was a three-stimulus auditory odd-ball task, target stimuli were the major stimuli of interest. Individual target trials underwent wavelet analysis to give power and phase-locking of delta (3 Hz), theta (4-7 Hz), alpha (8-12 Hz), beta (13-30 Hz) and gamma (30-50 Hz) frequencies for a 50 ms time window centred around the peak of the target P3. Delta power around the P3 peak was significantly reduced when participants were given dexamphetamine. Delta phase-locking was also reduced but only when analysis was targeted at the location of the peak P3 amplitude. In contrast, theta power and phase-locking were not affected by dexamphetamine. These findings suggest that increased catecholamine activity may be responsible for the power and phase-locking reductions of the auditory P3 delta component in patients with schizophrenia. Interestingly, dexamphetamine significantly increased gamma power around the P3 peak. We attempt to link this finding with the gamma alterations that have been found in patients with schizophrenia.

  15. Auxetic piezoelectric energy harvesters for increased electric power output

    Science.gov (United States)

    Li, Qiang; Kuang, Yang; Zhu, Meiling

    2017-01-01

    This letter presents a piezoelectric bimorph with auxetic (negative Poisson's ratio) behaviors for increased power output in vibration energy harvesting. The piezoelectric bimorph comprises a 2D auxetic substrate sandwiched between two piezoelectric layers. The auxetic substrate is capable of introducing auxetic behaviors and thus increasing the transverse stress in the piezoelectric layers when the bimorph is subjected to a longitudinal stretching load. As a result, both 31- and 32-modes are simultaneously exploited to generate electric power, leading to an increased power output. The increasing power output principle was theoretically analyzed and verified by finite element (FE) modelling. The FE modelling results showed that the auxetic substrate can increase the transverse stress of a bimorph by 16.7 times. The average power generated by the auxetic bimorph is 2.76 times of that generated by a conventional bimorph.

  16. Money in the Bank: Feeling Powerful Increases Saving

    OpenAIRE

    Emily N. Garbinsky; Anne-Kathrin Klesse; Jennifer Aaker

    2014-01-01

    Across five studies, this research reveals that feeling powerful increases saving. This effect is driven by the desire to maintain one's current state. When the purpose of saving is no longer to accumulate money but to spend it on a status-related product, the basic effect is reversed, and those who feel powerless save more. Further, if money can no longer aid in maintaining one's current state because power is already secure or because power is maintained by accumulating an alternative resou...

  17. Prony Analysis for Power System Transient Harmonics

    Directory of Open Access Journals (Sweden)

    Qi Li

    2007-01-01

    Full Text Available Proliferation of nonlinear loads in power systems has increased harmonic pollution and deteriorated power quality. Not required to have prior knowledge of existing harmonics, Prony analysis detects frequencies, magnitudes, phases, and especially damping factors of exponential decaying or growing transient harmonics. In this paper, Prony analysis is implemented to supervise power system transient harmonics, or time-varying harmonics. Further, to improve power quality when transient harmonics appear, the dominant harmonics identified from Prony analysis are used as the harmonic reference for harmonic selective active filters. Simulation results of two test systems during transformer energizing and induction motor starting confirm the effectiveness of the Prony analysis in supervising and canceling power system transient harmonics.

  18. RF Power Amplifier Analysis

    Directory of Open Access Journals (Sweden)

    M. Lokay

    1993-04-01

    Full Text Available The special program is presented for the demonstration of RF power transistor amplifiers for the purposes of the high-school education in courses of radio transmitters. The program is written in Turbo Pascal 6. 0 and enables to study the waveforms in selected points of the amplifier and to draw the trajectories of the working point in a plot of output transistor characteristics.

  19. Gov't to Spur Consumption by Increasing Purchasing Power

    Institute of Scientific and Technical Information of China (English)

    Xinhua

    2005-01-01

      The Chinese central government aims to spur domestic consump tion by increasing consumer purchasing power in the coming years in a bid to continue maintaining a steady development of the nation's economy.……

  20. Gov't to Spur Consumption by Increasing Purchasing Power

    Institute of Scientific and Technical Information of China (English)

    Xinhua

    2005-01-01

    @@ The Chinese central government aims to spur domestic consump tion by increasing consumer purchasing power in the coming years in a bid to continue maintaining a steady development of the nation's economy.

  1. Residual soil DNA extraction increases the discriminatory power between samples.

    Science.gov (United States)

    Young, Jennifer M; Weyrich, Laura S; Clarke, Laurence J; Cooper, Alan

    2015-06-01

    Forensic soil analysis relies on capturing an accurate and reproducible representation of the diversity from limited quantities of soil; however, inefficient DNA extraction can markedly alter the taxonomic abundance. The performance of a standard commercial DNA extraction kit (MOBIO PowerSoil DNA Isolation kit) and three modified protocols of this kit: soil pellet re-extraction (RE); an additional 24-h lysis incubation step at room temperature (RT); and 24-h lysis incubation step at 55°C (55) were compared using high-throughput sequencing of the internal transcribed spacer I ribosomal DNA. DNA yield was not correlated with fungal diversity and the four DNA extraction methods displayed distinct fungal community profiles for individual samples, with some phyla detected exclusively using the modified methods. Application of a 24 h lysis step will provide a more complete inventory of fungal biodiversity, and re-extraction of the residual soil pellet offers a novel tool for increasing discriminatory power between forensic soil samples.

  2. High power beam analysis

    Science.gov (United States)

    Aharon, Oren

    2014-02-01

    In various modern scientific and industrial laser applications, beam-shaping optics manipulates the laser spot size and its intensity distribution. However the designed laser spot frequently deviates from the design goal due to real life imperfections and effects, such as: input laser distortions, optical distortion, heating, overall instabilities, and non-linear effects. Lasers provide the ability to accurately deliver large amounts of energy to a target area with very high accuracy. Thus monitoring beam size power and beam location is of high importance for high quality results and repeatability. Depending on the combination of wavelength, beam size and pulse duration , laser energy is absorbed by the material surface, yielding into processes such as cutting, welding, surface treatment, brazing and many other applications. This article will cover the aspect of laser beam measurements, especially at the focal point where it matters the most. A brief introduction to the material processing interactions will be covered, followed by fundamentals of laser beam propagation, novel measurement techniques, actual measurement and brief conclusions.

  3. Compressive Power Spectral Analysis

    NARCIS (Netherlands)

    Ariananda, D.D.

    2015-01-01

    At the heart of digital signal processing (DSP) are the sampling and quantization processes, which convert analog signals into discrete samples and which are implemented in the form of analog to digital converters (ADCs). In some recent applications, there is an increased demand for DSP applications

  4. Does green consumerism increase the acceptance of wind power?

    DEFF Research Database (Denmark)

    Thøgersen, John; Noblet, Caroline

    2012-01-01

    based on a random sample of residents of the state of Maine, USA, we find that both everyday ‘‘ green ’’ behaviour and the acceptance of an expansion of wind power are rooted in environmental concern and that everyday ‘‘green’’ behaviour gives a significant contribution to predicting acceptance of wind...... power when controlling for environmental concern.Hence, the promotion of everyday ‘‘green’’ behaviours may prepare the grounds for increasing acceptance of more far-reaching changes in the population, such as an expansion of wind power....

  5. Power analysis in flexible automation

    Science.gov (United States)

    Titus, Nathan A.

    1992-12-01

    The performance of an automation or robotic device can be measured in terms of its power efficiency. Screw theory is used to mathematically define the task instantaneously with two screws. The task wrench defines the effect of the device on its environment, and the task twist describes the motion of the device. The tasks can be separated into three task types: kinetic, manipulative, and reactive. Efficiency metrics are developed for each task type. The output power is strictly a function of the task screws, while device input power is shown to be a function of the task, the device Jacobian, and the actuator type. Expressions for input power are developed for two common types of actuators, DC servometers and hydraulic actuators. Simple examples are used to illustrate how power analysis can be used for task/workspace planning, actuator selection, device configuration design, and redundancy resolution.

  6. Thermal Power Plant Performance Analysis

    CERN Document Server

    2012-01-01

    The analysis of the reliability and availability of power plants is frequently based on simple indexes that do not take into account the criticality of some failures used for availability analysis. This criticality should be evaluated based on concepts of reliability which consider the effect of a component failure on the performance of the entire plant. System reliability analysis tools provide a root-cause analysis leading to the improvement of the plant maintenance plan.   Taking in view that the power plant performance can be evaluated not only based on  thermodynamic related indexes, such as heat-rate, Thermal Power Plant Performance Analysis focuses on the presentation of reliability-based tools used to define performance of complex systems and introduces the basic concepts of reliability, maintainability and risk analysis aiming at their application as tools for power plant performance improvement, including: ·         selection of critical equipment and components, ·         defini...

  7. Quantifying the increasing sensitivity of power systems to climate variability

    Science.gov (United States)

    Bloomfield, H. C.; Brayshaw, D. J.; Shaffrey, L. C.; Coker, P. J.; Thornton, H. E.

    2016-12-01

    Large quantities of weather-dependent renewable energy generation are expected in power systems under climate change mitigation policies, yet little attention has been given to the impact of long term climate variability. By combining state-of-the-art multi-decadal meteorological records with a parsimonious representation of a power system, this study characterises the impact of year-to-year climate variability on multiple aspects of the power system of Great Britain (including coal, gas and nuclear generation), demonstrating why multi-decadal approaches are necessary. All aspects of the example system are impacted by inter-annual climate variability, with the impacts being most pronounced for baseload generation. The impacts of inter-annual climate variability increase in a 2025 wind-power scenario, with a 4-fold increase in the inter-annual range of operating hours for baseload such as nuclear. The impacts on peak load and peaking-plant are comparably small. Less than 10 years of power supply and demand data are shown to be insufficient for providing robust power system planning guidance. This suggests renewable integration studies—widely used in policy, investment and system design—should adopt a more robust approach to climate characterisation.

  8. Power converter simulation and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ghazy, M.A.

    1989-01-01

    There has been a great deal of progress made in computer aided design and analysis in the power electronic field. Many of the simulation packages are inefficient and time consuming in simulating switching converters. This thesis proposes an efficient, simple, general simulation approach to simulate any power converter with less computation time and space requirements on computer. In this approach the equations of power converters are formulated using network topology. In this thesis several procedures have been explained for the steady-state computation of power electronic circuits. Also, the steady-state analyses have been accomplished by a new technique called Fourier series method. For a complete system consisting of converters, filters, and electric machines, the simulation is complicated if a frequency domain technique is used. This thesis introduces a better technique which decouples the system into subsystems and simulates it in the time domain. The design of power converters using optimization techniques is presented in this thesis. Finally, the theory of Variable Structured Systems has been applied to power converters. Sliding mode control for DC-DC and DC-AC power converters is introduced as a tool to accomplish desired characteristics.

  9. Money in the bank : Feeling powerful increases saving

    NARCIS (Netherlands)

    Garbinsky, E.; Klesse, A.K.; Aaker, J.

    2014-01-01

    Across five studies, this research reveals that feeling powerful increases saving. This effect is driven by the desire to maintain one’s current state. When the purpose of saving is no longer to accumulate money but to spend it on a status-related product, the basic effect is reversed, and those who

  10. Improve your word power a concise way to increase your word power

    CERN Document Server

    Sawhney, Clifford

    2012-01-01

    A concise way to increase your word power English is a unique language which has innumerable great poets and authors from the past as well as the present, who have contributed profusely to its rich heritage….

  11. Optical Gravitational Wave Antenna with Increased Power Handling Capability

    CERN Document Server

    Matsko, Andrey B; Yamamoto, Hiroaki; Vyatchanin, Sergey P

    2015-01-01

    Fundamental sensitivity of an optical interferometric gravitational wave detector increases with increase of the optical power which, in turn, limited because of the opto-mechanical parametric instabilities of the interferometer. We propose to optimize geometrical shape of the mirrors of the detector to reduce the diffraction-limited finesse of unessential optical modes of the interferometer resulting in increase of the threshold of the opto-mechanical instabilities and subsequent increase of the measurement sensitivity. Utilizing parameters of the LIGO interferometer we found that the proposed technique allows constructing a Fabry-Perot interferometer with round trip diffraction loss of the fundamental mode not exceeding $5$~ppm, whereas the loss of the first dipole as well as the other high order modes exceed $1,000$~ppm and $8,000$~ppm, respectively. The optimization comes at the price of tighter tolerances on the mirror tilt stability, but does not result in a significant modification of the optical beam ...

  12. Application of Interline Power Flow Controller to Increase Transient Stability of Power System

    Directory of Open Access Journals (Sweden)

    Prechanon Kumkratug

    2010-01-01

    Full Text Available Problem statement: The Interline Power Flow Controller (IPFC is a novel device which can increase transient stability of power system. To verify the capability of the effect of IPFC on stability improvement of power system, the suitable mathematical model and control strategy of IPFC are needed to be presented. Approach: This study presented the mathematical model and control strategy of IPFC. The multi-series converters of IPFC are represented by multi-series voltage sources with associate transformer leakage reactance. The parameters of IPFC are modeled into power flow equation and thus it is used to determine control strategy. This study used Bang-Bang control strategy. The swing curves of the three phase faulted power system without and with an IPFC are tested and compared in various cases. Results: The swing curve of system without an IPFC get increased monotonically and thus the system can be considered as unstable whereas the swing curves of system with an IPFC can return to stable equilibrium point. Conclusion: The presented model of IPFC can help us to comprehend the effect of IPFC on transient stability improvement of power system. From simulation results, the IPFC can increase transient stability of power system.

  13. Caffeine Attenuates Decreases in Leg Power Without Increased Muscle Damage.

    Science.gov (United States)

    Ribeiro, Beatriz G; Morales, Anderson P; Sampaio-Jorge, Felipe; Barth, Thiago; de Oliveira, Marcio B C; Coelho, Gabriela M D O; Leite, Tiago C

    2016-08-01

    Ribeiro, BG, Morales, AP, Sampaio-Jorge, F, Barth, T, de Oliveira, MBC, Coelho, GMdO, and Leite, TC. Caffeine attenuates decreases in leg power without increased muscle damage. J Strength Cond Res 30(8): 2354-2360, 2016-Caffeine ingestion has been shown to be an effective ergogenic aid in several sports. Caffeine administration may increase exercise capacity, which could lead to a greater degree of muscle damage after exercise. This was a randomized, double-blind, placebo-controlled crossover study. Six male handball athletes ingested placebo (PLA) or caffeine (CAF) (6 mg·kg body mass) capsules on 2 different occasions. Sixty minutes after ingestion of the capsules, serum CAF levels were evaluated. Thereafter, all participants performed a protocol of vertical jumps (VJs). The protocol consisted of 4 sets of 30 seconds of continuous VJs with 60 seconds of recovery between sets. Blood lactate (LAC) and creatine kinase (CK) levels were determined before and after the protocol. We found significant differences in serum CAF levels between PLA (0.09 ± 0.18 µg·ml) vs. CAF (6.59 ± 4.44 µg·ml) (p 0.05). These results indicate that immediate ingestion of CAF (6 mg·kg body weight) can reduce the level of muscle fatigue and preserve leg power during the test, possibly resulting in increase in LAC. There was no increase in muscle damage, which indicates that immediate administration of (6 mg·kg body weight) CAF is safe. Thus, nutritional interventions with CAF could help athletes withstand a greater physiological overload during high-intensity training sessions. The results of this study would be applicable to sports and activities that require repetitive leg power.

  14. Power analysis of trials with multilevel data

    CERN Document Server

    Moerbeek, Mirjam

    2015-01-01

    Power Analysis of Trials with Multilevel Data covers using power and sample size calculations to design trials that involve nested data structures. The book gives a thorough overview of power analysis that details terminology and notation, outlines key concepts of statistical power and power analysis, and explains why they are necessary in trial design. It guides you in performing power calculations with hierarchical data, which enables more effective trial design.The authors are leading experts in the field who recognize that power analysis has attracted attention from applied statisticians i

  15. PowerFactory applications for power system analysis

    CERN Document Server

    Gonzalez-Longatt, Francisco

    2014-01-01

    This book presents a comprehensive set of guidelines and applications of DIgSILENT PowerFactory, an advanced power system simulation software package, for different types of power systems studies. Written by specialists in the field, it combines expertise and years of experience in the use of DIgSILENT PowerFactory with a deep understanding of power systems analysis. These complementary approaches therefore provide a fresh perspective on how to model, simulate and analyse power systems. It presents methodological approaches for modelling of system components, including both classical and non-

  16. Statistical Power in Meta-Analysis

    Science.gov (United States)

    Liu, Jin

    2015-01-01

    Statistical power is important in a meta-analysis study, although few studies have examined the performance of simulated power in meta-analysis. The purpose of this study is to inform researchers about statistical power estimation on two sample mean difference test under different situations: (1) the discrepancy between the analytical power and…

  17. Increased photovoltaic power output via diffractive spectrum separation.

    Science.gov (United States)

    Kim, Ganghun; Dominguez-Caballero, Jose A; Lee, Howard; Friedman, Daniel J; Menon, Rajesh

    2013-03-22

    In this Letter, we report the preliminary demonstration of a new paradigm for photovoltaic power generation that utilizes a broadband diffractive-optical element (BDOE) to efficiently separate sunlight into laterally spaced spectral bands. These bands are then absorbed by single-junction photovoltaic cells, whose band gaps correspond to the incident spectral bands. We designed such BDOEs by utilizing a modified version of the direct-binary-search algorithm. Gray scale lithography was used to fabricate these multilevel optics. They were experimentally characterized with an overall optical efficiency of 70% over a wavelength range of 350-1100 nm, which was in excellent agreement with simulation predictions. Finally, two prototype devices were assembled: one with a pair of copper indium gallium selenide based photovoltaic devices, and another with GaAs and c-Si photovoltaic devices. These devices demonstrated an increase in output peak electrical power of ∼ 42% and ∼ 22%, respectively, under white-light illumination. Because of the optical versatility and manufacturability of the proposed BDOEs, the reported spectrum-splitting approach provides a new approach toward low-cost solar power.

  18. Impact of Production from Photovoltaic Power Plants on Increase of Ancillary Services in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Martin Smocek

    2016-01-01

    Full Text Available Renewable energy resources represent a noticeable part of the overall energetic concept development. New integration of renewable energy resources into power grids has a significant impact on the reliability and quality of power supply. The major problem of the photovoltaic and wind power plants is their dependency on weather conditions, since it has a direct effect on their immediate output produced that shows stochastic behaviour. These stochastic outputs result in very adverse impacts on the power grid. Further development of these resources could lead to exceeding of the control and absorption abilities of the power grid. The power grid must be set in balance with respect to the production and consumption of electric power at any time. The operation of photovoltaic power plants impair keeping this balance. That has an adverse impact on the very operation and maintenance of network parameters within the extent required. This survey deals with analysis focused on operation of the photovoltaic power plants with respect to the increase of reserve power in ancillary services in the Czech Republic.

  19. Abstract thinking increases one’s sense of power

    NARCIS (Netherlands)

    Smith, P.K.; Wigboldus, D.H.J.; Dijksterhuis, A.J.

    2008-01-01

    One’s subjective sense of power often has greater influence on behavior than the amount of power one actually possesses. We propose that this sense of power may be determined in part by one’s style of information processing. As abstract thought is less constraining than concrete thought, and having

  20. Nuclear Power Plant Module, NPP-1: Nuclear Power Cost Analysis.

    Science.gov (United States)

    Whitelaw, Robert L.

    The purpose of the Nuclear Power Plant Modules, NPP-1, is to determine the total cost of electricity from a nuclear power plant in terms of all the components contributing to cost. The plan of analysis is in five parts: (1) general formulation of the cost equation; (2) capital cost and fixed charges thereon; (3) operational cost for labor,…

  1. Net energy analysis - powerful tool for selecting elective power options

    Energy Technology Data Exchange (ETDEWEB)

    Baron, S. [Brookhaven National Laboratory, Upton, NY (United States)

    1995-12-01

    A number of net energy analysis studies have been conducted in recent years for electric power production from coal, oil and uranium fuels; synthetic fuels from coal and oil shale; and heat and electric power from solar energy. This technique is an excellent indicator of investment costs, environmental impact and potential economic competitiveness of alternative electric power systems for energy planners from the Eastern European countries considering future options. Energy conservation is also important to energy planners and the net energy analysis technique is an excellent accounting system on the extent of energy resource conservation. The author proposes to discuss the technique and to present the results of his studies and others in the field. The information supplied to the attendees will serve as a powerful tool to the energy planners considering their electric power options in the future.

  2. Modelling of electrical power systems for power flow analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cogo, Joao Roberto [Escola Federal de Engenharia de Itajuba, MG (Brazil)

    1994-12-31

    The industry systems in Brazil are responsible for a consumption of over 50% (fifty per cent) of the total electrical power generated: therefore, they are import loads in power flow studies, and their modeling should be as much the best. Usually, in power flow studies, the industry systems are modeled by taking the influence of the power (active and reactive) and of the current on the voltage into account. Since the inducting motors, within the industry systems, represent at least 50% (fifty per cent) of the power consumption, and a large part of them is oversize, it is proposed to represent the industry systems as a function of the characteristic of power on shaft versus voltage into account. Since the induction motors, within the industry systems, represent at least 50% (fifty per cent) of the power consumption, and a large part of them is oversized, it is proposed to represent the industry systems as a function of the characteristics of power on shaft versus voltage for the analysis of power systems, aiming a load flow study. Thereafter, a model of an equivalent motor which has a basis the typical performance curve of an induction motor is present. This model is obtained from empirical parameters, surveyed from a population of over 1000 motors. (author) 3 refs., 1 fig., 4 tabs.

  3. SYNTHESIS OF MODULAR UNINTERRUPTED POWER SUPPLY SYSTEMS WITH INCREASED RELIABILITY

    Directory of Open Access Journals (Sweden)

    Grigorash O. V.

    2015-04-01

    Full Text Available The level of technical development today requires the creation of highly effective, including reliable, uninter-rupted power supply systems. We have shown modern requirements and design features of modern systems of uninterruptible power supply, which should be built on a modular principle. It is shown that the problem of synthesis of systems in a modular approach is addressing three issues: development of the structure of the system subject to the requirements of consumers to quality of power and the allowable time of power outage; determining the required level redundancy of major functional units (blocks, elements to ensure the required reliability of the system; - ensuring the most effective interconnection of modules, including electromagnetic compatibility, and the rational use during normal and emergency operation of the system. We have proposed new structural solution of the main functional units and uninterrupted power supply systems in modular design. To reduce EMI and improve efficiency uninterruptible power supply systems in the design of static converters we need to use a transformer with a rotating magnetic field. In addition, the prospective current is to be used as a source of renewable energy. Another promising approach is the use of direct frequency converters as voltage stabilizers and frequency of the current

  4. Magnetic metamaterial superlens for increased range wireless power transfer.

    Science.gov (United States)

    Lipworth, Guy; Ensworth, Joshua; Seetharam, Kushal; Huang, Da; Lee, Jae Seung; Schmalenberg, Paul; Nomura, Tsuyoshi; Reynolds, Matthew S; Smith, David R; Urzhumov, Yaroslav

    2014-01-10

    The ability to wirelessly power electrical devices is becoming of greater urgency as a component of energy conservation and sustainability efforts. Due to health and safety concerns, most wireless power transfer (WPT) schemes utilize very low frequency, quasi-static, magnetic fields; power transfer occurs via magneto-inductive (MI) coupling between conducting loops serving as transmitter and receiver. At the "long range" regime - referring to distances larger than the diameter of the largest loop - WPT efficiency in free space falls off as (1/d)(6); power loss quickly approaches 100% and limits practical implementations of WPT to relatively tight distances between power source and device. A "superlens", however, can concentrate the magnetic near fields of a source. Here, we demonstrate the impact of a magnetic metamaterial (MM) superlens on long-range near-field WPT, quantitatively confirming in simulation and measurement at 13-16 MHz the conditions under which the superlens can enhance power transfer efficiency compared to the lens-less free-space system.

  5. Failure analysis on China power grid based on power law

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng WENG; Yiguang HONG; Ancheng XUE; Shengwei MEI

    2006-01-01

    This paper is concerned with the mechanism of blackouts in China power system from the viewpoint of self-organized criticality. By using two estimation algorithms of scaled window variance (SWV) and rescaled rangestatistics (R/S), this paper studies the blackout data in China power system during 1988-1997. The result of analysis shows that the blackout data of 1994-1997 coincides well with the autocorrelation. Furthermore, it is found that the function of blackout probability vs. blackout size exhibits power law distribution.

  6. Supplement analysis, Southpoint power project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-16

    The Calpine Corporation applied to interconnect its proposed power plant with the Western Area Power Administration`s (Western) Parker-Davis project in western Arizona. Western, as a major electric transmission system owner is required by existing policies and regulations, to provide access to its transmission system, when requested by an eligible organization. The proposed interconnection would integrate a major source of new generation into the Parker-Davis system which would allow Calpine to supply its power to the electric wholesale market. Based on this application, Western`s proposed action is to enter into an interconnection agreement with Calpine.

  7. Power Analysis Software for Educational Researchers

    Science.gov (United States)

    Peng, Chao-Ying Joanne; Long, Haiying; Abaci, Serdar

    2012-01-01

    Given the importance of statistical power analysis in quantitative research and the repeated emphasis on it by American Educational Research Association/American Psychological Association journals, the authors examined the reporting practice of power analysis by the quantitative studies published in 12 education/psychology journals between 2005…

  8. ADVANCED POWER SYSTEMS ANALYSIS TOOLS

    Energy Technology Data Exchange (ETDEWEB)

    Robert R. Jensen; Steven A. Benson; Jason D. Laumb

    2001-08-31

    The use of Energy and Environmental Research Center (EERC) modeling tools and improved analytical methods has provided key information in optimizing advanced power system design and operating conditions for efficiency, producing minimal air pollutant emissions and utilizing a wide range of fossil fuel properties. This project was divided into four tasks: the demonstration of the ash transformation model, upgrading spreadsheet tools, enhancements to analytical capabilities using the scanning electron microscopy (SEM), and improvements to the slag viscosity model. The ash transformation model, Atran, was used to predict the size and composition of ash particles, which has a major impact on the fate of the combustion system. To optimize Atran key factors such as mineral fragmentation and coalescence, the heterogeneous and homogeneous interaction of the organically associated elements must be considered as they are applied to the operating conditions. The resulting model's ash composition compares favorably to measured results. Enhancements to existing EERC spreadsheet application included upgrading interactive spreadsheets to calculate the thermodynamic properties for fuels, reactants, products, and steam with Newton Raphson algorithms to perform calculations on mass, energy, and elemental balances, isentropic expansion of steam, and gasifier equilibrium conditions. Derivative calculations can be performed to estimate fuel heating values, adiabatic flame temperatures, emission factors, comparative fuel costs, and per-unit carbon taxes from fuel analyses. Using state-of-the-art computer-controlled scanning electron microscopes and associated microanalysis systems, a method to determine viscosity using the incorporation of grey-scale binning acquired by the SEM image was developed. The image analysis capabilities of a backscattered electron image can be subdivided into various grey-scale ranges that can be analyzed separately. Since the grey scale's intensity

  9. An Effective Distributed Model for Power System Transient Stability Analysis

    Directory of Open Access Journals (Sweden)

    MUTHU, B. M.

    2011-08-01

    Full Text Available The modern power systems consist of many interconnected synchronous generators having different inertia constants, connected with large transmission network and ever increasing demand for power exchange. The size of the power system grows exponentially due to increase in power demand. The data required for various power system applications have been stored in different formats in a heterogeneous environment. The power system applications themselves have been developed and deployed in different platforms and language paradigms. Interoperability between power system applications becomes a major issue because of the heterogeneous nature. The main aim of the paper is to develop a generalized distributed model for carrying out power system stability analysis. The more flexible and loosely coupled JAX-RPC model has been developed for representing transient stability analysis in large interconnected power systems. The proposed model includes Pre-Fault, During-Fault, Post-Fault and Swing Curve services which are accessible to the remote power system clients when the system is subjected to large disturbances. A generalized XML based model for data representation has also been proposed for exchanging data in order to enhance the interoperability between legacy power system applications. The performance measure, Round Trip Time (RTT is estimated for different power systems using the proposed JAX-RPC model and compared with the results obtained using traditional client-server and Java RMI models.

  10. Computer-aided power systems analysis

    CERN Document Server

    Kusic, George

    2008-01-01

    Computer applications yield more insight into system behavior than is possible by using hand calculations on system elements. Computer-Aided Power Systems Analysis: Second Edition is a state-of-the-art presentation of basic principles and software for power systems in steady-state operation. Originally published in 1985, this revised edition explores power systems from the point of view of the central control facility. It covers the elements of transmission networks, bus reference frame, network fault and contingency calculations, power flow on transmission networks, generator base power setti

  11. Power System Transients Analysis by Wavelet Transforms

    Institute of Scientific and Technical Information of China (English)

    陈维荣; 宋永华; 赵蔚

    2002-01-01

    In contrast to Fourier transform, wavelet transform is especially suitable for transient analysis because of its time-frequency characteristics with automatically-adjusted window lengths. Research shows that wavelet transform is one of the most powerful tools for power system transient analysis. The basic ideas of wavelet transform are presented in the paper together with several power system applications. It is clear that wavelet transform has some clear advantages over other transforms in detecting, analyzing, and identifying various types of power system transients.

  12. Exergoeconomic analysis of a nuclear power plant

    Science.gov (United States)

    Moreno, Roman Miguel

    Exergoeconomic analysis of a nuclear power plant is a focus of this dissertation. Specifically, the performance of the Palo Verde Nuclear Power Plant in Arizona is examined. The analysis combines thermodynamic second law exergy analysis with economics in order to assign costs to the loss and destruction of exergy. This work was done entirely with an interacting spreadsheets notebook. The procedures are to first determine conventional energy flow, where the thermodynamic stream state points are calculated automatically. Exergy flow is then evaluated along with destruction and losses. The capital cost and fixed investment rate used for the economics do not apply specifically to the Palo Verde Plant. Exergy costing is done next involving the solution of about 90 equations by matrix inversion. Finally, the analysis assigns cost to the exergy destruction and losses in each component. In this work, the cost of electricity (exergy), including capital cost, leaving the generator came to 38,400 /hr. The major exergy destruction occurs in the reactor where fission energy transfer is limited by the maxiμm permissible clad temperature. Exergy destruction costs were: reactor--18,207 hr, the low pressure turbine-2,000 /hr, the condenser--1,700 hr, the steam generator-1,200 $/hr. The inclusion of capital cost and O&M are important in new system design assessments. When investigating operational performance, however, these are sunk costs; only fuel cost needs to be considered. The application of a case study is included based on a real modification instituted at Palo Verde to reduce corrosion steam generator problems; the pressure in the steam generator was reduced from 1072 to 980 psi. Exergy destruction costs increased in the low pressure turbine and in the steam generator, but decreased in the reactor vessel and the condenser. The dissertation demonstrates the procedures and tools required for exergoeconomic analysis whether in the evaluation of a new nuclear reactor system

  13. Stochastic Power Grid Analysis Considering Process Variations

    CERN Document Server

    Ghanta, Praveen; Panda, Rajendran; Wang, Janet

    2011-01-01

    In this paper, we investigate the impact of interconnect and device process variations on voltage fluctuations in power grids. We consider random variations in the power grid's electrical parameters as spatial stochastic processes and propose a new and efficient method to compute the stochastic voltage response of the power grid. Our approach provides an explicit analytical representation of the stochastic voltage response using orthogonal polynomials in a Hilbert space. The approach has been implemented in a prototype software called OPERA (Orthogonal Polynomial Expansions for Response Analysis). Use of OPERA on industrial power grids demonstrated speed-ups of up to two orders of magnitude. The results also show a significant variation of about $\\pm$ 35% in the nominal voltage drops at various nodes of the power grids and demonstrate the need for variation-aware power grid analysis.

  14. Dynamic security issues in autonomous power systems with increasing wind power penetration

    DEFF Research Database (Denmark)

    Margaris, I.D.; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2011-01-01

    Technical requirements set by the network operators nowadays include various aspects, such as fault ride-through capability of wind turbines during faults, voltage-reactive power control and overall control of the wind farms as conventional power plants. Detailed models for the power system as well...... as for the wind farms are therefore essential for power system studies related to these issues, especially when applied to non interconnected systems with high wind power penetration. Detailed generic models for three different wind turbine technologies – Active Stall Induction Generator (ASIG), Doubly Fed...... Asynchronous Generator (DFAG) and Permanent Magnet Synchronous Generator (PMSG) – are applied and issues regarding interaction with the power system are investigated. This paper provides conclusions about the dynamic security of non-interconnected power systems with high wind power penetration based...

  15. Increasing flexibility of coal power plant by control system modifications

    Directory of Open Access Journals (Sweden)

    Marušić Ante

    2016-01-01

    Full Text Available Expanding implementation of intermittent renewable energy sources has already started to change the role of thermal power plants in energy systems across Europe. Traditionally base load plants are now forced to operate as peaking plants. A familiar transition in upcoming years is expected in Croatia and coal power plant operators are preparing accordingly. To evaluate cycling capabilities and control system operation for flexible operation of selected 210 MW coal plant, series of tests with different load gradients were performed and results were thoroughly analyzed. Two possible “bottlenecks” are identified, thermal stress in superheater header, and achievable ramping rate considering operational limitations of coal feeders, firing system and evaporator dynamics. Several unexpected readings were observed, usually caused by malfunctioning sensors and equipment, resulting in unexpected oscillations of superheated steam temperature. Based on superheater geometry and experimental data, maximal steam temperature gradient during ramping was evaluated. Since thermal stress was well inside the safety margins, the simulation model of the whole boiler was used to evaluate achievable ramping on electric side.

  16. Increased durability concrete for generation of pillars power lines

    Directory of Open Access Journals (Sweden)

    Yakovlev Grigory

    2016-01-01

    Full Text Available In this researches multilayered carbon nanotubes of production of the French corporation “Arkema” were used. It has followed features: diameter of 10-15 nanometers and up to 15 microns long. Multilayered carbon nanotubes were used for increasing of physics and technology properties of cement concrete. It was established that at introduction of multilayered carbon nanotubes in amount of 0.006% of the mass led concrete durability increases by 28%, resistance to frost from F200 to F400, tightness to water from W8 to W14.

  17. Covariate Adjustment Strategy Increases Power in the Randomized Controlled Trial With Discrete-Time Survival Endpoints

    Science.gov (United States)

    Safarkhani, Maryam; Moerbeek, Mirjam

    2013-01-01

    In a randomized controlled trial, a decision needs to be made about the total number of subjects for adequate statistical power. One way to increase the power of a trial is by including a predictive covariate in the model. In this article, the effects of various covariate adjustment strategies on increasing the power is studied for discrete-time…

  18. Analysis on Resources Utilization of Thermal Power Industry

    Institute of Scientific and Technical Information of China (English)

    Mi Jianhua

    2005-01-01

    Based on the analysis and comparison of coal, oil and water consumptions in thermal power plants, thispaper introduces the present state of resources utilization in thermal power industry, and points out that the poten-tial of resources saving lies mainly in cutting down coal consumption and increasing the ratio of large-sized thermalunits. Measures and suggestions for upgrading resources utilization are put forward, such as to optimize coal-firedthermal power structure, develop cogeneration, clean coal combustion techniques and gas-steam combined cycletechniques. The existing thermal power plants shall execute technical retrofits and popularize water saving techniques.

  19. Application of ORC power station to increase electric power of gas compression ignition engine

    Directory of Open Access Journals (Sweden)

    Mocarski Szymon

    2017-01-01

    Full Text Available The paper presents the calculation results of efficiency of the subcritical low temperature ORC power station powered by waste heat resulting from the process of cooling a stationary compression ignition engine. The source of heat to supply the ORC power station is the heat in a form of water jet cooling the engine at a temperature of 92°C, and the exhaust gas stream at a temperature of 420°C. The study considers three variants of systems with the ORC power stations with different ways of using heat source. The first variant assumes using just engine cooling water to power the ORC station. In the second variant the ORC system is powered solely by a heat flux from the combustion gases by means of an intermediary medium - thermal oil, while the third variant provides the simultaneous management of both heat fluxes to heat the water stream as a source of power supply to the ORC station. The calculations were made for the eight working media belonging both to groups of so-called dry media (R218, R1234yf, R227ea and wet media (R32, R161, R152a, R134a, R22.

  20. Development of Standardized Power Electronic Components, Subsystems, and Systems for Increased Modularity and Scalability

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, S.; Pink, C.; Price, J.; Kroposki, B.; Kern, G.

    2007-11-01

    Power electronics devices hold substantial promise for making distributed energy applications more efficient and cost effective. This project is motivated towards developing and testing inverters that will allow distributed energy systems to provide ancillary services such as voltage and VAR regulation, and increased grid reliability by seamlessly transitioning between grid-tied and stand-alone operation modes. The objectives of this project are to identify system integration and optimization issues and technologies and to provide solutions through research, analysis, and testing of power electronic interfaces for distributed energy applications that are cost-competitive and have substantially faster response times than conventional technologies. In addition, the testing of power electronics interfaces will develop a technical basis for performance assessment for distributed energy systems, subsystems, and components that will finally create a foundation for standardized measurements and test procedures. The ultimate goal for this research is to advance the potential benefits of distributed energy to provide ancillary services, enhance power system reliability, and allow customer choice.

  1. Forecasting increasing rate of power consumption based on immune genetic algorithm combined with neural network

    Institute of Scientific and Technical Information of China (English)

    杨淑霞

    2008-01-01

    Considering the factors affecting the increasing rate of power consumption, the BP neural network structure and the neural network forecasting model of the increasing rate of power consumption were established. Immune genetic algorithm was applied to optimizing the weight from input layer to hidden layer, from hidden layer to output layer, and the threshold value of neuron nodes in hidden and output layers. Finally, training the related data of the increasing rate of power consumption from 1980 to 2000 in China, a nonlinear network model between the increasing rate of power consumption and influencing factors was obtained. The model was adopted to forecasting the increasing rate of power consumption from 2001 to 2005, and the average absolute error ratio of forecasting results is 13.521 8%. Compared with the ordinary neural network optimized by genetic algorithm, the results show that this method has better forecasting accuracy and stability for forecasting the increasing rate of power consumption.

  2. An Analysis of the Internal Audit of Ningde Nuclear Power Company to Increase the Value of the Target%浅析宁德核电以增值为目标的内部审计

    Institute of Scientific and Technical Information of China (English)

    屈志鹏

    2015-01-01

    To increase the value of the organizationˊs objectives is to achieve the inte rnal audit of the internal audit of the important functions of the new definition of value-added services for enterprises as the fundamental objective of internal audit. Internal audit of Ningde nuclear power company is will add value to the enterprise as its ultimate goal and positioning, fully explain the meaning of the unique value of internal audit, and on this basis into practice.%增加价值从而实现组织目标是内部审计的重要职能,内部审计新的定义将为企业提供增值服务作为内部审计的根本目标. 宁德核电内部审计正是将为企业增加价值作为其最终目标与定位,充分阐释了其独有的内部审计增值的内涵,并在此基础上付诸实践.

  3. Joint Operation of Several Types of Power Plants to Increasing Net Profit in Deregulated Power Market

    Directory of Open Access Journals (Sweden)

    S. Sajedi

    2012-03-01

    Full Text Available This study proposes joint operation of power plant and electric energy storage plant in order to maximizing overall profit in a restructured electricity market. The goal is investigating the coupling efficiency on profit increment considering various intensities of power plant’s fuel constraint. In order to reach this goal, the amount of overall profits of fuel-constrained power plant, battery plant and their coupling are first calculated in a specific time interval. Then, the coupling efficiency is determined using incremental profit rate. Having an appropriate strategy to calculate this parameter is essential. Hence, a comprehensive approach to selfschedule of individual and coupled plants is developed. This comprehensive self-scheduling approach is therefore formulated and solved as a Mixed Integer Non-linear Programming (MINLP problem. Numerical results for a case study are discussed.

  4. Operating the Irish power system with increased levels of wind power

    DEFF Research Database (Denmark)

    Tuohy, A.; Denny, E.; Meibom, Peter

    2008-01-01

    This paper summarises some of the main impacts of large amounts of wind power installed in the island of Ireland. Using results from various studies performed on this system, it is shown that wind power will impact on all time frames, from seconds to daily planning of the system operation. Results...... from studies examining operation of the system with up to approximately 40% of electricity provided by wind show that some of the most important aspects to be considered include the type of wind turbine technology, the provision of reserve to accommodate wind forecasting error and the method used...

  5. Power and performance software analysis and optimization

    CERN Document Server

    Kukunas, Jim

    2015-01-01

    Power and Performance: Software Analysis and Optimization is a guide to solving performance problems in modern Linux systems. Power-efficient chips are no help if the software those chips run on is inefficient. Starting with the necessary architectural background as a foundation, the book demonstrates the proper usage of performance analysis tools in order to pinpoint the cause of performance problems, and includes best practices for handling common performance issues those tools identify. Provides expert perspective from a key member of Intel's optimization team on how processors and memory

  6. Multilateral analysis of increasing collective dose and new ALARA programme.

    Science.gov (United States)

    Oumi, Tadashi; Morii, Yasuki; Imai, Toshirou

    2011-07-01

    JAPC (The Japan Atomic Power Company) is the only electric power company that operates different types of nuclear reactors in Japan; it operates two BWRs (boiling water reactors), one pressurised water reactor and one gas cooled reactor. JAPC has been conducting various activities aimed at reducing radiation dose received by workers for over 45 y. Recently, the collective dose resulting from periodic maintenance has increased at each plant because of the replacement of large equipment and the unexpected extension of the outage period. In particular, the collective dose at Tokai-2 is one of the highest among Japanese BWR plants((1)), owing to the replacement and strengthening of equipment to meet earthquake-proof requirements. In this study, the authors performed a multilateral analysis of unacceptably a large collective dose and devised a new ALARA programme that includes a 3D dose prediction map and the development of machines to assist workers.

  7. Power Estimation in Multivariate Analysis of Variance

    Directory of Open Access Journals (Sweden)

    Jean François Allaire

    2007-09-01

    Full Text Available Power is often overlooked in designing multivariate studies for the simple reason that it is believed to be too complicated. In this paper, it is shown that power estimation in multivariate analysis of variance (MANOVA can be approximated using a F distribution for the three popular statistics (Hotelling-Lawley trace, Pillai-Bartlett trace, Wilk`s likelihood ratio. Consequently, the same procedure, as in any statistical test, can be used: computation of the critical F value, computation of the noncentral parameter (as a function of the effect size and finally estimation of power using a noncentral F distribution. Various numerical examples are provided which help to understand and to apply the method. Problems related to post hoc power estimation are discussed.

  8. Obesity is not associated with increased knee joint torque and power during level walking.

    Science.gov (United States)

    DeVita, Paul; Hortobágyi, Tibor

    2003-09-01

    While it is widely speculated that obesity causes increased loads on the knee leading to joint degeneration, this concept is untested. The purpose of the study was to identify the effects of obesity on lower extremity joint kinetics and energetics during walking. Twenty-one obese adults were tested at self-selected (1.29m/s) and standard speeds (1.50m/s) and 18 lean adults were tested at the standard speed. Motion analysis and force platform data were combined to calculate joint torques and powers during the stance phase of walking. Obese participants were more erect with 12% less knee flexion and 11% more ankle plantarflexion in self-selected compared to standard speeds (both pKnee and ankle torques were 17% and 11% higher (pknee work and positive ankle work were 68% and 11% higher (ppowers were statistically identical at the hip and knee but were 88% and 61% higher (both pknee torque and power at their self-selected walking speed and equal knee torque and power while walking at the same speed as lean individuals. We propose that the ability to reorganize neuromuscular function during gait may enable some obese individuals to maintain skeletal health of the knee joint and this ability may also be a more accurate risk indicator for knee osteoarthritis than body weight.

  9. Power Systems Life Cycle Analysis Tool (Power L-CAT).

    Energy Technology Data Exchange (ETDEWEB)

    Andruski, Joel; Drennen, Thomas E.

    2011-01-01

    The Power Systems L-CAT is a high-level dynamic model that calculates levelized production costs and tracks environmental performance for a range of electricity generation technologies: natural gas combined cycle (using either imported (LNGCC) or domestic natural gas (NGCC)), integrated gasification combined cycle (IGCC), supercritical pulverized coal (SCPC), existing pulverized coal (EXPC), nuclear, and wind. All of the fossil fuel technologies also include an option for including carbon capture and sequestration technologies (CCS). The model allows for quick sensitivity analysis on key technical and financial assumptions, such as: capital, O&M, and fuel costs; interest rates; construction time; heat rates; taxes; depreciation; and capacity factors. The fossil fuel options are based on detailed life cycle analysis reports conducted by the National Energy Technology Laboratory (NETL). For each of these technologies, NETL's detailed LCAs include consideration of five stages associated with energy production: raw material acquisition (RMA), raw material transport (RMT), energy conversion facility (ECF), product transportation and distribution (PT&D), and end user electricity consumption. The goal of the NETL studies is to compare existing and future fossil fuel technology options using a cradle-to-grave analysis. The NETL reports consider constant dollar levelized cost of delivered electricity, total plant costs, greenhouse gas emissions, criteria air pollutants, mercury (Hg) and ammonia (NH3) emissions, water withdrawal and consumption, and land use (acreage).

  10. Shuttle Electrical Power Analysis Program (SEPAP) distribution circuit analysis report

    Science.gov (United States)

    Torina, E. M.

    1975-01-01

    An analysis and evaluation was made of the operating parameters of the shuttle electrical power distribution circuit under load conditions encountered during a normal Sortie 2 Mission with emphasis on main periods of liftoff and landing.

  11. Comparative analysis of existing models for power-grid synchronization

    CERN Document Server

    Nishikawa, Takashi

    2015-01-01

    The dynamics of power-grid networks is becoming an increasingly active area of research within the physics and network science communities. The results from such studies are typically insightful and illustrative, but are often based on simplifying assumptions that can be either difficult to assess or not fully justified for realistic applications. Here we perform a comprehensive comparative analysis of three leading models recently used to study synchronization dynamics in power-grid networks -- a fundamental problem of practical significance given that frequency synchronization of all power generators in the same interconnection is a necessary condition for a power grid to operate. We show that each of these models can be derived from first principles within a common framework based on the classical model of a generator, thereby clarifying all assumptions involved. This framework allows us to view power grids as complex networks of coupled second-order phase oscillators with both forcing and damping terms. U...

  12. Increasing Transparency Through a Multiverse Analysis.

    Science.gov (United States)

    Steegen, Sara; Tuerlinckx, Francis; Gelman, Andrew; Vanpaemel, Wolf

    2016-09-01

    Empirical research inevitably includes constructing a data set by processing raw data into a form ready for statistical analysis. Data processing often involves choices among several reasonable options for excluding, transforming, and coding data. We suggest that instead of performing only one analysis, researchers could perform a multiverse analysis, which involves performing all analyses across the whole set of alternatively processed data sets corresponding to a large set of reasonable scenarios. Using an example focusing on the effect of fertility on religiosity and political attitudes, we show that analyzing a single data set can be misleading and propose a multiverse analysis as an alternative practice. A multiverse analysis offers an idea of how much the conclusions change because of arbitrary choices in data construction and gives pointers as to which choices are most consequential in the fragility of the result.

  13. Multi Megawatt Power System Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, Glen Reed; Harvego, Edwin Allan; Schnitzler, Bruce Gordon; Seifert, Gary Dean; Sharpe, John Phillip; Verrill, Donald Alan; Watts, Kenneth Donald; Parks, Benjamin Travis

    2001-11-01

    Missions to the outer planets or to near-by planets requiring short times and/or increased payload carrying capability will benefit from nuclear power. A concept study was undertaken to evaluate options for a multi-megawatt power source for nuclear electric propulsion. The nominal electric power requirement was set at 15 MWe with an assumed mission profile of 120 days at full power, 60 days in hot standby, and another 120 days of full power, repeated several times for 7 years of service. Of the numerous options considered, two that appeared to have the greatest promise were a gas-cooled reactor based on the NERVA Derivative design, operating a closed cycle Brayton power conversion system; and a molten lithium-cooled reactor based on SP-100 technology, driving a boiling potassium Rankine power conversion system. This study examined the relative merits of these two systems, seeking to optimize the specific mass. Conclusions were that either concept appeared capable of approaching the specific mass goal of 3-5 kg/kWe estimated to be needed for this class of mission, though neither could be realized without substantial development in reactor fuels technology, thermal radiator mass efficiency, and power conversion and distribution electronics and systems capable of operating at high temperatures. Though the gas-Brayton systems showed an apparent advantage in specific mass, differences in the degree of conservatism inherent in the models used suggests expectations for the two approaches may be similar. Brayton systems eliminate the need to deal with two-phase flows in the microgravity environment of space.

  14. Analysis of Photovoltaic Maximum Power Point Trackers

    Science.gov (United States)

    Veerachary, Mummadi

    The photovoltaic generator exhibits a non-linear i-v characteristic and its maximum power point (MPP) varies with solar insolation. An intermediate switch-mode dc-dc converter is required to extract maximum power from the photovoltaic array. In this paper buck, boost and buck-boost topologies are considered and a detailed mathematical analysis, both for continuous and discontinuous inductor current operation, is given for MPP operation. The conditions on the connected load values and duty ratio are derived for achieving the satisfactory maximum power point operation. Further, it is shown that certain load values, falling out of the optimal range, will drive the operating point away from the true maximum power point. Detailed comparison of various topologies for MPPT is given. Selection of the converter topology for a given loading is discussed. Detailed discussion on circuit-oriented model development is given and then MPPT effectiveness of various converter systems is verified through simulations. Proposed theory and analysis is validated through experimental investigations.

  15. Power Analysis Tutorial for Experimental Design Software

    Science.gov (United States)

    2014-11-01

    Details ............................................................ D-1 Appendix E – JMP Monte Carlo Simulation Script...freedom for error. • In Design Expert, when constructing a design, you are asked for delta and sigma . The default model for power analysis is...Designed Experiments. Third Edition. New York: John Wiley and Sons, 2009. 12. Muthen, Linda, and Bengt Muthen. “How to Use a Monte Carlo Study to

  16. 78 FR 57373 - Appalachian Power Company; Notice of Application To Increase Water Withdraw and Construct Water...

    Science.gov (United States)

    2013-09-18

    ... Energy Regulatory Commission Appalachian Power Company; Notice of Application To Increase Water Withdraw and Construct Water Withdraw Facilty Pursuant to License Article 202 and Soliciting Comments, Motions... Filed: July 31, 2013. d. Applicant: Appalachian Power Company (licensee). e. Name of Project:...

  17. Control of a hybrid HVDC link to increase inter-regional power transfer

    DEFF Research Database (Denmark)

    Kotb, Omar; Ghandhari, Mehrdad; Eriksson, Robert

    2016-01-01

    This paper examines the application of a hybrid HVDC link in a two area power system with the purpose of increasing the inter-regional power transfer. A hybrid HVDC system combines both LCCs and VSCs, and hence it is capable of combining the benefits of both converter technologies, such as reduced...

  18. Transmission expansion planning under increased uncertainties, towards efficient and sustainable power systems

    NARCIS (Netherlands)

    Ciupuliga, A.R.

    2013-01-01

    The ongoing liberalization process around the world has led to the emergence of energy markets, facilitating more international trade between countries making the best use of energy resources and optimizing overall power systems. Consequently, inter-area power exchanges have significantly increased

  19. Power analysis of static VAr compensators

    Energy Technology Data Exchange (ETDEWEB)

    Quintela, F.R.; Arevalo, J.M.G.; Redondo, R.C. [Escuela Tecnica Superior de Ingenieria Industrial, Universidad de Salamanca, 37700 Bejar (Spain)

    2008-07-15

    Analysis of three-phase loads usually assume them to be three impedances in a star or triangle connection. This is the reason why obtained results can only be considered valid for passive loads, strictly speaking. Analysis leading to the proposal of some static compensators is usually performed in this way, which induces to believe that this compensators are only valid for passive loads. An analysis procedure, which uses only powers to describe loads, is expounded in this paper. If applied to the analysis of static compensators, it reveals unequivocally their usefulness with active and passive three-phase loads. Therefore, this method is more general and, as it will be seen, easier. (author)

  20. Output beam analysis of high power COIL

    Institute of Scientific and Technical Information of China (English)

    Deli Yu(于德利); Fengting Sang(桑凤亭); Yuqi Jin(金玉奇); Yizhu Sun(孙以珠)

    2003-01-01

    As the output power of a chemical oxygen iodine laser (COIL) increases, the output laser beam instabilityappears as the far-field beam spot drift and deformation for the large Fresnel number unstable resonator.In order to interpret this phenomenon, an output beam mode simulation code was developed with the fastFourier transform method. The calculation results show that the presence of the nonuniform gain in COILproduces a skewed output intensity distribution, which causes the mirror tilt and bulge due to the thermalexpansion. With the output power of COIL increases, the mirror surfaces, especially the back surface ofthe scraper mirror, absorb more and more heat, which causes the drift and deformation of far field beamspot seriously. The initial misalignment direction is an important factor for the far field beam spot driftingand deformation.

  1. Dynamic Analysis of Power System Voltage Stability.

    Science.gov (United States)

    Gebreselassie, Assefa

    This thesis investigates the effects of loads and voltage regulators on the dynamic voltage stability of power systems. The analysis focuses on the interactions of machine flux dynamics with loads and voltage control devices. The results are based on eigenvalue analysis of the linearized models and time simulation of the nonlinear models, using models from the Power System Toolbox, a Matlab -based package for the simulation and small signal analysis of nonlinear power systems. The voltage stability analysis results are developed using a single machine single load system with typical machine and network parameters and the NPCC 10-machine system. Dynamic models for generators, exciters and loads are used. The generator is modeled with a pair of poles and one damper circuit in both the d-axis and the q-axis. Saturation effects are included in the model. The IEEE Type DC1 DC commutator exciter model is used for all the exciters. Five different types of loads: constant impedance, constant current, constant power, a first order induction motor model (slip model) and a third order induction motor model (slip-flux model) are considered. The modes of instability and the stability limits of the different representation of loads are examined for two different operating modes of the exciters. The first, when all the exciters are on automatic control and the second when some exciters are on manual control. Modal participation factors are used to determine the characteristics of the critical modes. The characteristics of the unstable modes are verified by performing time simulation of the nonlinear models. Oscillatory and non-oscillatory instabilities are experienced by load buses when all the exciters are on automatic control and some exciters are on manual control respectively, for loads which are predominantly constant power and induction motors. It is concluded that the mode of instability does not depend on the type of loads but on the operating condition of the exciters

  2. PowerSpy: Location Tracking using Mobile Device Power Analysis

    OpenAIRE

    Michalevsky, Yan; Nakibly, Gabi; Schulman, Aaron; Veerapandian, Gunaa Arumugam; Boneh, Dan

    2015-01-01

    Modern mobile platforms like Android enable applications to read aggregate power usage on the phone. This information is considered harmless and reading it requires no user permission or notification. We show that by simply reading the phone's aggregate power consumption over a period of a few minutes an application can learn information about the user's location. Aggregate phone power consumption data is extremely noisy due to the multitude of components and applications that simultaneously ...

  3. Analysis of Linear MHD Power Generators

    Energy Technology Data Exchange (ETDEWEB)

    Witalis, E.A.

    1965-02-15

    The finite electrode size effects on the performance of an infinitely long MHD power generation duct are calculated by means of conformal mapping. The general conformal transformation is deduced and applied in a graphic way. The analysis includes variations in the segmentation degree, the Hall parameter of the gas and the electrode/insulator length ratio as well as the influence of the external circuitry and loading. A general criterion for a minimum of the generator internal resistance is given. The same criterion gives the conditions for the occurrence of internal current leakage between adjacent electrodes. It is also shown that the highest power output at a prescribed efficiency is always obtained when the current is made to flow between exactly opposed electrodes. Curves are presented showing the power-efficiency relations and other generator properties as depending on the segmentation degree and the Hall parameter in the cases of axial and transverse power extraction. The implications of limiting the current to flow between a finite number of identical electrodes are introduced and combined with the condition for current flow between opposed electrodes. The characteristics of generators with one or a few external loads can then be determined completely and examples are given in a table. It is shown that the performance of such generators must not necessarily be inferior to that of segmented generators with many independent loads. However, the problems of channel end losses and off-design loading have not been taken into consideration.

  4. Noise analysis in power distribution systems

    Science.gov (United States)

    Danisor, Alin

    2016-12-01

    This paper proposes an analysis, especially in time domain, of the electrical noise existent on the power distribution lines. This study is important for the use of powerlines as a channel of information transmissions. This information may refer to analog signals and as well to digital signals. The main problem addressed in this paper consists in the characterization of the background noise and to establish his statistical proprieties. It is very important to know if the noise induced in the transmission channel is a stationary one, or even an ergodic one. The main parameters like the mean value, the mean square value were determined in this paper. The approximation of the probability density function of each statistical parameter was studied. The pulses induced in the transmission channel by the transient phenomena of the power electrical systems were considered deterministic signals and their contributions were not included in this study.

  5. Increased power to weight ratio of piezoelectric energy harvesters through integration of cellular honeycomb structures

    Science.gov (United States)

    Chandrasekharan, N.; Thompson, L. L.

    2016-04-01

    The limitations posed by batteries have compelled the need to investigate energy harvesting methods to power small electronic devices that require very low operational power. Vibration based energy harvesting methods with piezoelectric transduction in particular has been shown to possess potential towards energy harvesters replacing batteries. Current piezoelectric energy harvesters exhibit considerably lower power to weight ratio or specific power when compared to batteries the harvesters seek to replace. To attain the goal of battery-less self-sustainable device operation the power to weight ratio gap between piezoelectric energy harvesters and batteries need to be bridged. In this paper the potential of integrating lightweight honeycomb structures with existing piezoelectric device configurations (bimorph) towards achieving higher specific power is investigated. It is shown in this study that at low excitation frequency ranges, replacing the solid continuous substrate of conventional bimorph with honeycomb structures of the same material results in a significant increase in power to weight ratio of the piezoelectric harvester. At higher driving frequency ranges it is shown that unlike the traditional piezoelectric bimorph with solid continuous substrate, the honeycomb substrate bimorph can preserve optimum global design parameters through manipulation of honeycomb unit cell parameters. Increased operating lifetime and design flexibility of the honeycomb core piezoelectric bimorph is demonstrated as unit cell parameters of the honeycomb structures can be manipulated to alter mass and stiffness properties of the substrate, resulting in unit cell parameter significantly influencing power generation.

  6. Power flow analysis for DC voltage droop controlled DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav

    2014-01-01

    This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification...... is carried out by comparing the calculation results with detailed time domain simulation results. With the droop parameters as variables in the power flow analysis, their effects on power sharing and secondary voltage regulation can now be analytically studied, and specialized optimization in the upper level...... control can also be made accordingly. Case studies on power sharing and secondary voltage regulation are carried out using proposed power flow analysis....

  7. Advanced Wireless Power Transfer Vehicle and Infrastructure Analysis (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Gonder, J.; Brooker, A.; Burton, E.; Wang, J.; Konan, A.

    2014-06-01

    This presentation discusses current research at NREL on advanced wireless power transfer vehicle and infrastructure analysis. The potential benefits of E-roadway include more electrified driving miles from battery electric vehicles, plug-in hybrid electric vehicles, or even properly equipped hybrid electric vehicles (i.e., more electrified miles could be obtained from a given battery size, or electrified driving miles could be maintained while using smaller and less expensive batteries, thereby increasing cost competitiveness and potential market penetration). The system optimization aspect is key given the potential impact of this technology on the vehicles, the power grid and the road infrastructure.

  8. Economic analysis of nuclear power generation

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Dong; Choi, Young Myung; Kim, Hwa Sup; Lee, Man Ki; Moon, Kee Hwan; Kim, Seung Su; Chae, Kyu Nam

    1996-12-01

    The major contents in this study are as follows : (1) Efforts are made to examine the role of nuclear energy considering environmental regulation. An econometric model for energy demand and supply including carbon tax imposition is established. (2) Analysis for the learning effect of nuclear power plant operation is performed. The study is focused to measure the effect of technology homogeneity on the operation performance. (3) A preliminary capital cost of the KALIMER is estimated by using cost computer program, which is developed in this study. (author). 36 refs.,46 tabs., 15 figs.

  9. Cost Benefit Analysis of the Power Storage System Considering Outage Cost in the Deregulated Power Market

    Science.gov (United States)

    Tsuru, Hirokazu; Fujii, Yasumasa

    In this paper, the authors propose the mathematical model which derives the optimal operation strategies of an on-site power storage system through the use of stochastic dynamic programming technique. The model takes account of the variations and uncertainties of electricity market prices as well as the outage costs of power grid failures. The market price fluctuation is modeled with stochastic differential equation. The stochastic state transitions between normal and failed systems are modeled with exponential density functions. The derived optimal operation indicates that the economic value of the storage system may be increased substantially, if the avoided outage costs are explicitly taken into account. The results of the sensitivity analysis indicate that the most influential parameters are the magnitude of outage cost and the mean time to failure of power grid.

  10. A coherency-based method to increase dynamic security in power systems

    Energy Technology Data Exchange (ETDEWEB)

    De Tuglie, E. [Dipartimento di Ingegneria dell' Ambiente e per lo Sviluppo Sostenibile - DIASS, Politecnico di Bari, Viale del Turismo 8, 74100 Taranto (Italy); Iannone, S.M.; Torelli, F. [Dipartimento di Elettrotecnica ed Elettronica - DEE, Politecnico di Bari, Via Re David 200, 70125 Bari (Italy)

    2008-08-15

    Dynamic security analysis is the evaluation of the ability of a system to withstand contingencies by surviving transient conditions to acceptable steady-state operative states. When potential instability due to contingency is detected, preventive action may be desired to improve the system security. This is very important in the on-line operation of a power system, especially when the system is stability-limited. The method proposed in this paper is based on the idea that increasing coherency between generators in the transient behaviour following a system perturbation gives rise to a more stable system. In this paper, we suggest the use of the ''input-output feedback-linearization'' with a reference trajectory obtained using a system dynamic equivalent based on the centre of inertia. To quantify coherency levels a new coherency indicator has been assumed for the given reference trajectory. The result is an increasing level in coherency, critical clearing time and system stability. The method is tested on the IEEE 30 bus test system. (author)

  11. Spacecraft Electrical Power System (EPS) generic analysis tools and techniques

    Science.gov (United States)

    Morris, Gladys M.; Sheppard, Mark A.

    1992-01-01

    An overview is provided of the analysis tools and techiques used in modeling the Space Station Freedom electrical power system, as well as future space vehicle power systems. The analysis capabilities of the Electrical Power System (EPS) are described and the EPS analysis tools are surveyed.

  12. Advanced Power Plant Development and Analysis Methodologies

    Energy Technology Data Exchange (ETDEWEB)

    A.D. Rao; G.S. Samuelsen; F.L. Robson; B. Washom; S.G. Berenyi

    2006-06-30

    Under the sponsorship of the U.S. Department of Energy/National Energy Technology Laboratory, a multi-disciplinary team led by the Advanced Power and Energy Program of the University of California at Irvine is defining the system engineering issues associated with the integration of key components and subsystems into advanced power plant systems with goals of achieving high efficiency and minimized environmental impact while using fossil fuels. These power plant concepts include 'Zero Emission' power plants and the 'FutureGen' H2 co-production facilities. The study is broken down into three phases. Phase 1 of this study consisted of utilizing advanced technologies that are expected to be available in the 'Vision 21' time frame such as mega scale fuel cell based hybrids. Phase 2 includes current state-of-the-art technologies and those expected to be deployed in the nearer term such as advanced gas turbines and high temperature membranes for separating gas species and advanced gasifier concepts. Phase 3 includes identification of gas turbine based cycles and engine configurations suitable to coal-based gasification applications and the conceptualization of the balance of plant technology, heat integration, and the bottoming cycle for analysis in a future study. Also included in Phase 3 is the task of acquiring/providing turbo-machinery in order to gather turbo-charger performance data that may be used to verify simulation models as well as establishing system design constraints. The results of these various investigations will serve as a guide for the U. S. Department of Energy in identifying the research areas and technologies that warrant further support.

  13. 76 FR 16394 - Analysis of Horizontal Market Power Under the Federal Power Act

    Science.gov (United States)

    2011-03-23

    ... Energy Regulatory Commission Analysis of Horizontal Market Power Under the Federal Power Act AGENCY... should revise its approach for examining horizontal ] market power concerns in transactions under Sec. 203 of the Federal Power Act to reflect the Horizontal Merger Guidelines issued by the Department...

  14. Increasing power generation for scaling up single-chamber air cathode microbial fuel cells

    KAUST Repository

    Cheng, Shaoan

    2011-03-01

    Scaling up microbial fuel cells (MFCs) requires a better understanding the importance of the different factors such as electrode surface area and reactor geometry relative to solution conditions such as conductivity and substrate concentration. It is shown here that the substrate concentration has significant effect on anode but not cathode performance, while the solution conductivity has a significant effect on the cathode but not the anode. The cathode surface area is always important for increasing power. Doubling the cathode size can increase power by 62% with domestic wastewater, but doubling the anode size increases power by 12%. Volumetric power density was shown to be a linear function of cathode specific surface area (ratio of cathode surface area to reactor volume), but the impact of cathode size on power generation depended on the substrate strength (COD) and conductivity. These results demonstrate the cathode specific surface area is the most critical factor for scaling-up MFCs to obtain high power densities. © 2010 Elsevier Ltd.

  15. Laguna Verde after the extended power increase; Laguna Verde despues del aumento de potencia extendido

    Energy Technology Data Exchange (ETDEWEB)

    Herrera C, M. N.; Castaneda G, M. A.; Cardenas J, J. B.; Garcia de la C, F. M., E-mail: mitzi.herrera@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2012-10-15

    The project of extended power increase that was implemented in both units of the nuclear power plant of Laguna Verde beginning with the stage feasibility evaluation in nuclear side of the facilities, that is to say the affectation of the power increase in the equipment s, systems and components of the nuclear power plant; besides the feasibility evaluation a study cost-benefit for the rehabilitated and modernization of the equipment s, systems and components of Plant Balance was realized. Once considered technical and economically feasible the project began the engineering evaluations required to carry out the licensing of the new operation conditions, as well as beginning to the elaboration of the technical specifications purchase of the equipment s, systems and components of the Plant Balance. While on one hand was carried out the administration of the licensing of the extended power increase for other was carried out the necessary engineering to make the physical changes in the conventional side of the nuclear power plant. Once concluded the constructive stage beginning the final stage of the project, the starting-up tests, operation and performance of the Units under the new operation conditions. This work describes this last stage that contains the technical base, the realized tests and the obtained results. (Author)

  16. A Study on the Active Induction Control of Upstream Wind Turbines for total power increases

    Science.gov (United States)

    Kim, Hyungyu; Kim, Kwansoo; Paek, Insu; Bottasso, Carlo L.; Campagnolo, Filippo

    2016-09-01

    In this study, the effect of active induction control of upstream wind turbines is investigated. Two scaled wind turbines having a rotor diameter of 1 m with a spacing of four times of the rotor diameter were used to experimentally validate the concept. Also, an in-house c code was used to simulate the same two wind turbines and see if the experimental observations can be obtained. From the experiment, approximately 0.81% increase of total power could be observed. Although the simulation results were not exactly the same as the experimental results but the shape was similar and the maximum power increase of 0.27% was predicted. Also from further simulation using NREL 5MW wind turbines instead of scaled wind turbines with realistic ambient turbulence intensity, it was found that the power increase could become more than 1%.

  17. Human hippocampal increases in low-frequency power during associative prediction violations.

    Science.gov (United States)

    Chen, Janice; Dastjerdi, Mohammad; Foster, Brett L; LaRocque, Karen F; Rauschecker, Andreas M; Parvizi, Josef; Wagner, Anthony D

    2013-10-01

    Environmental cues often trigger memories of past events (associative retrieval), and these memories are a form of prediction about imminent experience. Learning is driven by the detection of prediction violations, when the past and present diverge. Using intracranial electroencephalography (iEEG), we show that associative prediction violations elicit increased low-frequency power (in the slow-theta range) in human hippocampus, that this low-frequency power increase is modulated by whether conditions allow predictions to be generated, that the increase rapidly onsets after the moment of violation, and that changes in low-frequency power are not present in adjacent perirhinal cortex. These data suggest that associative mismatch is computed within hippocampus when cues trigger predictions that are violated by imminent experience.

  18. New Mersenne Number Transform Diffusion Power Analysis

    Directory of Open Access Journals (Sweden)

    M. F. Al-Gailani

    2011-01-01

    Full Text Available Problem statement: Due to significant developments in the processing power and parallel processing technologies, the existing encryption algorithms are increasingly susceptible to attacks, such as side-channel attacks, for example. Designing new encryption algorithms that work efficiently on different platforms and security levels to protect the transmitted data from any possible attacks is one of the most important issues in today’s information and network security. The aim is to find more secure, reliable and flexible systems that can run as a ratified standard, with reasonable computational complexity for a sufficient service time. To expand the longevity of the algorithm, it is important to be designed to work efficiently on a variety of block sizes and key lengths according to the security demand. A sensible solution is the suggested use of a parameter transform. Approach: The present study evaluates the appropriateness of the New Mersenne Number Transform for security applications by analyzing and estimating its avalanche and diffusion power. Results: The results confirm that the transform in general reflects good avalanche characteristics that are for most cases over 50% and can be up to 100%. The lower bound can be further improved by increasing the modulus and/or the transform length. Conclusion: This New Mersenne Number Transform is highly flexible and adaptable for this application. It can be involved in the design of a secure cryptosystem for the following reasons; changing a single input element makes drastic changes in the output elements and vice versa (sensitivity, provides variable block size and key length (parameterization. Has long transform length (power of two, is error free and its inverse is the same with a scale factor of (1/N which simplifies implementation of both encryption and decryption. Finally, it is appropriate for real time implementations such as fast algorithms, which can be applied to it, to speed up

  19. An ABC analysis for power generation project

    Directory of Open Access Journals (Sweden)

    Batool Hasani

    2013-07-01

    Full Text Available One of the primary concerns on performance measurement is to know how much a particular project cost. However, using traditional method on project-based products often leads to inappropriate results. In this paper, we re-examine this issue by comparing the cost of a power station construction project using ABC versus traditional method. The results of survey show that ABC method is capable of providing better estimates for overhead costs compared with traditional method. In other words, ABC method helps reduce some of the unnecessary overhead cost items and increase on some other cost components. This helps increase the relative efficiency of the system by reducing total cost of project.

  20. Power consumption analysis DBD plasma ozone generator

    Science.gov (United States)

    Nur, M.; Restiwijaya, M.; Muchlisin, Z.; Susan, I. A.; Arianto, F.; Widyanto, S. A.

    2016-11-01

    Studies on the consumption of energy by an ozone generator with various constructions electrodes of dielectric barrier discharge plasma (DBDP) reactor has been carried out. This research was done to get the configuration of the reactor, that is capable to produce high ozone concentrations with low energy consumption. BDBP reactors were constructed by spiral- cylindrical configuration, plasma ozone was generated by high voltage AC voltage up to 25 kV and maximum frequency of 23 kHz. The reactor consists of an active electrode in the form of a spiral-shaped with variation diameter Dc, and it was made by using copper wire with diameter Dw. In this research, we variated number of loops coil windings N as well as Dc and Dw. Ozone concentrations greater when the wire's diameter Dw and the diameter of the coil windings applied was greater. We found that impedance greater will minimize the concentration of ozone, in contrary to the greater capacitance will increase the concentration of ozone. The ozone concentrations increase with augmenting of power. Maximum power is effective at DBD reactor spiral-cylinder is on the Dc = 20 mm, Dw = 1.2 mm, and the number of coil windings N = 10 loops with the resulting concentration is greater than 20 ppm and it consumes energy of 177.60 watts

  1. Battery Resistance Analysis of ISS Power System

    Science.gov (United States)

    Newstadt, Gregory E.

    2004-01-01

    The computer package, SPACE (Systems Power Analysis for Capability Evaluation) was created by the members of LT-9D to perform power analysis and modeling of the electrical power system on the International Space Station (ISS). Written in FORTRAN, SPACE comprises thousands of lines of code and has been used profficiently in analyzing missions to the ISS. LT-9D has also used its expertise recently to investigate the batteries onboard the Hubble telescope. During the summer of 2004, I worked with the members of LT-9D, under the care of Dave McKissock. Solar energy will power the ISS through eight solar arrays when the ISS is completed, although only two arrays are currently connected. During the majority of the periods of sunlight, the solar arrays provide enough energy for the ISS. However, rechargeable Nickel-Hydrogen batteries are used during eclipse periods or at other times when the solar arrays cannot be used (at docking for example, when the arrays are turned so that they will not be damaged by the Shuttle). Thirty-eight battery cells are connected in series, which make up an ORU (Orbital Replacement Unit). An ISS "battery" is composed of two ORUs. a great deal of time into finding the best way to represent them in SPACE. During my internship, I investigated the resistance of the ISS batteries. SPACE constructs plots of battery charge and discharge voltages vs. time using a constant current. To accommodate for a time-varying current, the voltages are adjusted using the formula, DeltaV = DeltaI * Cell Resistance. To enhance our model of the battery resistance, my research concentrated on several topics: investigating the resistance of a qualification unit battery (using data gathered by LORAL), comparing the resistance of the qualification unit to SPACE, looking at the internal resistance and wiring resistance, and examining the impact of possible recommended changes to SPACE. The ISS batteries have been found to be very difficult to model, and LT-9D has

  2. Performance Analysis of Reconfigurable SRAM Cell for Low Power Applications

    Directory of Open Access Journals (Sweden)

    Dillibabu.Mannem

    2012-06-01

    Full Text Available The majority of space taken in an integrated circuit is the memory. SRAM design consists of key considerations, such as increased speed, low power and reduced layout area. A cell which is functional at the nominal supply voltage, can fail at a lower voltage. From a system perspective this leads to a higher bit-error rate with voltage scaling and limits the opportunity for power saving. While this is a serious bottleneck for SRAM arrays used for data storage. This paper presents a performance analysis of reconfigurable SRAM cell for low power application. Simulations using TSMC 0.35um technology show that the SRAM cell read & write access times are 1.53ns and 1.93ns. Mentor Graphics ELDO and EZ-wave are used for simulations.

  3. Low-load Slow Movement Squat Training Increases Muscle Size and Strength but Not Power.

    Science.gov (United States)

    Usui, S; Maeo, S; Tayashiki, K; Nakatani, M; Kanehisa, H

    2016-04-01

    We tested a hypothesis that low-load squat training with slow movement and tonic force generation (LST) would increase muscle size and strength but not necessarily power. Healthy young men were assigned to LST [50% one-repetition maximum (1-RM) load, 3 s for lowering/lifting without pause: n=9] or low-load normal speed (LN: 50% 1-RM load, 1 s for lowering/lifting with 1-s pause; n=7) groups. Both groups underwent an 8-week squat training program (10 repetitions/set, 3 sets/day, and 3 days/week) using the assigned methods. Before and after the intervention, quadriceps femoris muscle thickness, maximal torque during isometric hip extension and knee extension, 1-RM squat, lifting power from squatting position and rate of electromyography rise (RER) in knee extensors during the task, leg extension power and vertical jump height were measured. After the intervention, the LN group showed no changes in all the variables. The LST group significantly (Pmuscle thickness (6-10%), isometric hip extension torque (18%) and 1-RM squat (10%), but not isometric knee extension torque, lifting power and RER, leg extension power and vertical jump height. These results suggest that LST can increase muscle size and task-related strength, but has little effect on power production during dynamic explosive movements.

  4. Lunar Polar Illumination for Power Analysis

    Science.gov (United States)

    Fincannon, James

    2008-01-01

    This paper presents illumination analyses using the latest Earth-based radar digital elevation model (DEM) of the lunar south pole and an independently developed analytical tool. These results enable the optimum sizing of solar/energy storage lunar surface power systems since they quantify the timing and durations of illuminated and shadowed periods. Filtering and manual editing of the DEM based on comparisons with independent imagery were performed and a reduced resolution version of the DEM was produced to reduce the analysis time. A comparison of the DEM with lunar limb imagery was performed in order to validate the absolute heights over the polar latitude range, the accuracy of which affects the impact of long range, shadow-casting terrain. Average illumination and energy storage duration maps of the south pole region are provided for the worst and best case lunar day using the reduced resolution DEM. Average illumination fractions and energy storage durations are presented for candidate low energy storage duration south pole sites. The best site identified using the reduced resolution DEM required a 62 hr energy storage duration using a fast recharge power system. Solar and horizon terrain elevations as well as illumination fraction profiles are presented for the best identified site and the data for both the reduced resolution and high resolution DEMs compared. High resolution maps for three low energy storage duration areas are presented showing energy storage duration for the worst case lunar day, surface height, and maximum absolute surface slope.

  5. A power flow based model for the analysis of vulnerability in power networks

    Science.gov (United States)

    Wang, Zhuoyang; Chen, Guo; Hill, David J.; Dong, Zhao Yang

    2016-10-01

    An innovative model which considers power flow, one of the most important characteristics in a power system, is proposed for the analysis of power grid vulnerability. Moreover, based on the complex network theory and the Max-Flow theorem, a new vulnerability index is presented to identify the vulnerable lines in a power grid. In addition, comparative simulations between the power flow based model and existing models are investigated on the IEEE 118-bus system. The simulation results demonstrate that the proposed model and the index are more effective in power grid vulnerability analysis.

  6. Intermittency in Switching Power Converters: Theoretical Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yu-fei; CHEN Jun-ning; TSE Chi K.; QIU Shui-sheng; KE Dao-ming; SHI Long-xing; SUN Wei-feng

    2006-01-01

    In view of reasonable explanation of intermittent subharmonics and chaos that can be gained from coupling filter between circuits,this paper discusses a method that maps time bifurcation with parameter bifurcation.Based on this mapping method,the general analysis method of characteristic multiplier,which is originally aimed at parameter bifurcation,can be used for the study of intermittency,i.e.,time bifurcation.In this paper,all researches coming from characteristic multipliers,parameter-bifurcation diagrams,and the largest Lyapunov exponent indicate the same results as those produced by simulation and experiment.Thus,it is proved theoretically that the intermittency in switching power converter can be explained in terms of coupling of spurious interference.

  7. Seismic analysis of nuclear power plant structures

    Science.gov (United States)

    Go, J. C.

    1973-01-01

    Primary structures for nuclear power plants are designed to resist expected earthquakes of the site. Two intensities are referred to as Operating Basis Earthquake and Design Basis Earthquake. These structures are required to accommodate these seismic loadings without loss of their functional integrity. Thus, no plastic yield is allowed. The application of NASTRAN in analyzing some of these seismic induced structural dynamic problems is described. NASTRAN, with some modifications, can be used to analyze most structures that are subjected to seismic loads. A brief review of the formulation of seismic-induced structural dynamics is also presented. Two typical structural problems were selected to illustrate the application of the various methods of seismic structural analysis by the NASTRAN system.

  8. Conceptual Design of Solar-micro Hydro Power Plant to Increase Conversion Efficiency for Supporting Remote Tribal Community of Bangladesh

    Directory of Open Access Journals (Sweden)

    Anmona Shabnam Pranti

    2014-11-01

    Full Text Available Bangladesh is endowed with people along with limited primary energy sources and low electrification rate. Most of the hilly areas are out of the coverage of national grid where tribal people, a significant part of the country, are dwelling. The economic development of the whole country depends upon their advancement which is related to the electrification rate. Available micro hydro potential in hilly region could be a solution for this crisis if modified design is used. This paper deals with a new design of water power potential conversion efficiency increment of a micro hydro power plant to 95% from about 50% by using solar power for heating the water. In this proposed hybrid design, a parabolic reflector is considered to be used after comparative solar intensity analysis on different micro hydro power sites in Bangladesh to increase the velocity as well as the flow rate through penstock by heating the water to increase power production and efficiency. The main purpose of this concept is to supply electricity to more people, especially, remote tribal community by available renewable energy sources for economic development.

  9. Measurement Error and Equating Error in Power Analysis

    Science.gov (United States)

    Phillips, Gary W.; Jiang, Tao

    2016-01-01

    Power analysis is a fundamental prerequisite for conducting scientific research. Without power analysis the researcher has no way of knowing whether the sample size is large enough to detect the effect he or she is looking for. This paper demonstrates how psychometric factors such as measurement error and equating error affect the power of…

  10. Informed conditioning on clinical covariates increases power in case-control association studies.

    Science.gov (United States)

    Zaitlen, Noah; Lindström, Sara; Pasaniuc, Bogdan; Cornelis, Marilyn; Genovese, Giulio; Pollack, Samuela; Barton, Anne; Bickeböller, Heike; Bowden, Donald W; Eyre, Steve; Freedman, Barry I; Friedman, David J; Field, John K; Groop, Leif; Haugen, Aage; Heinrich, Joachim; Henderson, Brian E; Hicks, Pamela J; Hocking, Lynne J; Kolonel, Laurence N; Landi, Maria Teresa; Langefeld, Carl D; Le Marchand, Loic; Meister, Michael; Morgan, Ann W; Raji, Olaide Y; Risch, Angela; Rosenberger, Albert; Scherf, David; Steer, Sophia; Walshaw, Martin; Waters, Kevin M; Wilson, Anthony G; Wordsworth, Paul; Zienolddiny, Shanbeh; Tchetgen, Eric Tchetgen; Haiman, Christopher; Hunter, David J; Plenge, Robert M; Worthington, Jane; Christiani, David C; Schaumberg, Debra A; Chasman, Daniel I; Altshuler, David; Voight, Benjamin; Kraft, Peter; Patterson, Nick; Price, Alkes L

    2012-01-01

    Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI), smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from low-BMI cases are larger than those estimated from high-BMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals on the basis of phenotype (case-control ascertainment) or phenotype and clinical covariates (case-control-covariate ascertainment). While current approaches improve power in studies with random ascertainment, they often lose power under case-control ascertainment and fail to capture available power increases under case-control-covariate ascertainment. We show that an informed conditioning approach, based on the liability threshold model with parameters informed by external epidemiological information, fully accounts for disease prevalence and non-random ascertainment of phenotype as well as covariates and provides a substantial increase in power while maintaining a properly controlled false-positive rate. Our method outperforms standard case-control association tests with or without covariates, tests of gene x covariate interaction, and previously proposed tests for dealing with covariates in ascertained data, with especially large improvements in the case of case-control-covariate ascertainment. We investigate empirical case-control studies of type 2 diabetes, prostate cancer, lung cancer, breast cancer, rheumatoid arthritis, age-related macular degeneration, and end-stage kidney disease over a total of 89,726 samples. In these datasets, informed conditioning outperforms logistic regression for 115 of the 157 known associated variants investigated (P-value = 1 × 10(-9)). The improvement varied across diseases with a 16% median increase in χ(2) test statistics and a

  11. Theoretical Studies of Active Power/angle Sub-matrix in Power Flow Jacobian for Power System Analysis

    Institute of Scientific and Technical Information of China (English)

    CAO Guo-yun; ZHANG Qing; CHUNG T S; CHEN Chen

    2008-01-01

    Properties of the active power/angle sub-matrix in the power flow Jacobian for power system analysis are studied. The sub-matrix is a dominant and irreducible matrix under very general conditions of power systems, so that it is invertible. Also the necessary conditions for its singularity are given. These theoretical rsuts can be used to clarify the ambiguous understanding of the sub-matrix in current literature, and also provide the theoretical foundations for the applications based on reduced power flow Jacobian. Numerical simulation on the IEEE 118-bus power system is used to illustrate our results.

  12. Wired: impacts of increasing power line use by a growing bird population

    Science.gov (United States)

    Moreira, Francisco; Encarnação, Vitor; Rosa, Gonçalo; Gilbert, Nathalie; Infante, Samuel; Costa, Julieta; D’Amico, Marcello; Martins, Ricardo C.; Catry, Inês

    2017-02-01

    Power lines are increasingly widespread across many regions of the planet. Although these linear infrastructures are known for their negative impacts on bird populations, through collision and electrocution, some species take advantage of electricity pylons for nesting. In this case, estimation of the net impact of these infrastructures at the population level requires an assessment of trade-offs between positive and negative impacts. We compiled historical information (1958–2014) of the Portuguese white stork Ciconia ciconia population to analyze long-term changes in numbers, distribution range and use of nesting structures. White stork population size increased 660% up to 12000 breeding pairs between 1984 and 2014. In the same period, the proportion of nests on electricity pylons increased from 1% to 25%, likely facilitated by the 60% increase in the length of the very high tension power line grid (holding the majority of the nests) in the stork’s distribution range. No differences in breeding success were registered for storks nesting on electricity pylons versus other structures, but a high risk of mortality by collision and electrocution with power lines was estimated. We discuss the implications of this behavioral change, and of the management responses by power line companies, both for stork populations and for managers.

  13. Increase of power output by change of ion transport direction in a plant microbial fuel cell

    NARCIS (Netherlands)

    Timmers, R.A.; Strik, D.P.B.T.B.; Hamelers, H.V.M.; Buisman, C.J.N.

    2013-01-01

    The plant microbial fuel cell (PMFC) is a technology for the production of renewable and clean bioenergy based on photosynthesis. To increase the power output of the PMFC, the internal resistance (IR) must be reduced. The objective of the present study was to reduce the membrane resistance by changi

  14. Increasing input power dynamic range of SOA by shifting the transparent wavelength of tunable optical filter

    DEFF Research Database (Denmark)

    Yu, Jianjun; Jeppesen, Palle

    2001-01-01

    is only 2-3 ps long. The input power dynamic range (IPDR) can be strongly increased by shifting the TOF and the direction of the shifted transparent wavelength is different for 10 Gb/s return-to-zero (RZ) or nonreturn-to-zero (NRZ) signals. The transparent wavelength of the TOF should be shifted...

  15. PROMOTION OF PRODUCTS AND ANALYSIS OF MARKET OF POWER TOOLS

    Directory of Open Access Journals (Sweden)

    Sergey S. Rakhmanov

    2014-01-01

    Full Text Available The article describes the general situation of power tools on the market, both in Russia and in the world. A comparative analysis of competitors, market structure analysis of power tools, as well as assessment of competitiveness of some major product lines. Also the analysis methods of promotion used by companies selling tools, competitive analysis range Bosch, the leader in its segment, power tools available on the market in Russia.

  16. Overview of methods to increase dryout power in CANDU fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Groeneveld, D.C., E-mail: degroeneveld@gmail.com [Chalk River Laboratories, AECL, Chalk River (Canada); University of Ottawa, Department of Mechanical Engineering, Ottawa (Canada); Leung, L.K.H. [Chalk River Laboratories, AECL, Chalk River (Canada); Park, J.H. [Korean Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-06-15

    Highlights: • Small changes in bundle geometry can have noticeable effects on the bundle CHF. • Rod spacing devices can results in increases of over 200% in CHF. • CHF enhancement decays exponentially downstream from spacers. • CHF-enhancing bundle appendages also increase the post-CHF heat transfer. - Abstract: In CANDU reactors some degradation in the CCP (critical channel power, or power corresponding to the first occurrence of CHF in any fuel channel) will occur with time because of ageing effects such as pressure-tube diametral creep, increase in reactor inlet-header temperature, increased hydraulic resistance of feeders. To compensate for the ageing effects, various options for recovering the loss in CCP are described in this paper. They include: (i) increasing the bundle heated perimeter, (ii) optimizing the bundle configuration, (iii) optimizing core flow and flux distribution, (iv) reducing the bundle hydraulic resistance, (v) use of CHF-enhancing bundle appendages, (vi) more precise experimentation, and (vii) redefining CHF. The increase in CHF power has been quantified based on experiments on full-scale bundles and subchannel code predictions. The application of several of these CHF enhancement principles has been used in the development of the 43-rod CANFLEX bundle.

  17. Power-Law Dynamics of Membrane Conductances Increase Spiking Diversity in a Hodgkin-Huxley Model.

    Directory of Open Access Journals (Sweden)

    Wondimu Teka

    2016-03-01

    Full Text Available We studied the effects of non-Markovian power-law voltage dependent conductances on the generation of action potentials and spiking patterns in a Hodgkin-Huxley model. To implement slow-adapting power-law dynamics of the gating variables of the potassium, n, and sodium, m and h, conductances we used fractional derivatives of order η≤1. The fractional derivatives were used to solve the kinetic equations of each gate. We systematically classified the properties of each gate as a function of η. We then tested if the full model could generate action potentials with the different power-law behaving gates. Finally, we studied the patterns of action potential that emerged in each case. Our results show the model produces a wide range of action potential shapes and spiking patterns in response to constant current stimulation as a function of η. In comparison with the classical model, the action potential shapes for power-law behaving potassium conductance (n gate showed a longer peak and shallow hyperpolarization; for power-law activation of the sodium conductance (m gate, the action potentials had a sharp rise time; and for power-law inactivation of the sodium conductance (h gate the spikes had wider peak that for low values of η replicated pituitary- and cardiac-type action potentials. With all physiological parameters fixed a wide range of spiking patterns emerged as a function of the value of the constant input current and η, such as square wave bursting, mixed mode oscillations, and pseudo-plateau potentials. Our analyses show that the intrinsic memory trace of the fractional derivative provides a negative feedback mechanism between the voltage trace and the activity of the power-law behaving gate variable. As a consequence, power-law behaving conductances result in an increase in the number of spiking patterns a neuron can generate and, we propose, expand the computational capacity of the neuron.

  18. Power-Law Dynamics of Membrane Conductances Increase Spiking Diversity in a Hodgkin-Huxley Model.

    Science.gov (United States)

    Teka, Wondimu; Stockton, David; Santamaria, Fidel

    2016-03-01

    We studied the effects of non-Markovian power-law voltage dependent conductances on the generation of action potentials and spiking patterns in a Hodgkin-Huxley model. To implement slow-adapting power-law dynamics of the gating variables of the potassium, n, and sodium, m and h, conductances we used fractional derivatives of order η≤1. The fractional derivatives were used to solve the kinetic equations of each gate. We systematically classified the properties of each gate as a function of η. We then tested if the full model could generate action potentials with the different power-law behaving gates. Finally, we studied the patterns of action potential that emerged in each case. Our results show the model produces a wide range of action potential shapes and spiking patterns in response to constant current stimulation as a function of η. In comparison with the classical model, the action potential shapes for power-law behaving potassium conductance (n gate) showed a longer peak and shallow hyperpolarization; for power-law activation of the sodium conductance (m gate), the action potentials had a sharp rise time; and for power-law inactivation of the sodium conductance (h gate) the spikes had wider peak that for low values of η replicated pituitary- and cardiac-type action potentials. With all physiological parameters fixed a wide range of spiking patterns emerged as a function of the value of the constant input current and η, such as square wave bursting, mixed mode oscillations, and pseudo-plateau potentials. Our analyses show that the intrinsic memory trace of the fractional derivative provides a negative feedback mechanism between the voltage trace and the activity of the power-law behaving gate variable. As a consequence, power-law behaving conductances result in an increase in the number of spiking patterns a neuron can generate and, we propose, expand the computational capacity of the neuron.

  19. [Voluntary alpha-power increasing training impact on the heart rate variability].

    Science.gov (United States)

    Bazanova, O M; Balioz, N V; Muravleva, K B; Skoraia, M V

    2013-01-01

    In order to study the effect of the alpha EEG power increasing training at heart rate variability (HRV) as the index of the autonomic regulation of cognitive functions there were follow tasks: (1) to figure out the impact of biofeedback in the voluntary increasing the power in the individual high-frequency alpha-band effect on heart rate variability and related characteristics of cognitive and emotional spheres, (2) to determine the nature of the relationship between alpha activity indices and heart rate variability, depending on the alpha-frequency EEG pattern at rest (3) to examine how the individual alpha frequency EEG pattern is reflected in changes HRV as a result of biofeedback training. Psychometric indicators of cognitive performance, the characteristics of the alpha-EEG activity and heart rate variability (HRV) as LF/HF and pNN50 were recorded in 27 healthy men aged 18-34 years, before, during, and after 10 sessions of training of voluntary increase in alpha power in the individual high-frequency alpha band with eyes closed. To determine the biofeedback effect on the alpha power increasing training, data subjects are compared in 2 groups: experimental (14) with the real and the control group (13 people)--with mock biofeedback. The follow up effect of trainings was studied through month over the 10 training sessions. Results showed that alpha biofeedback training enhanced the fluency and accuracy in cognitive performance, decreased anxiety and frontal EMG, increased resting frequency, width and power in individual upper alpha range only in participants with low baseline alpha frequency. While mock biofeedback increased resting alpha power only in participants with high baseline resting alpha frequency and did change neither cognitive performance, nor HRV indices. Biofeedback training eliminated the alpha power decrease in response to arithmetic task in both with high and low alpha frequency participants and this effect was followed up over the month. Mock

  20. Electric power systems analysis and control

    CERN Document Server

    Saccomanno, Fabio

    2003-01-01

    "Highly relevant and timely in scope, the book is essential reading for anyone associated with electric power systems, including students and teachers of power engineering courses, professionals in the industry, consultants, and researchers."--Jacket.

  1. Increased Power Capture by Rotor Speed–Dependent Yaw Control of Wind Turbines

    DEFF Research Database (Denmark)

    Kragh, Knud Abildgaard; Fleming, Paul A.; Scholbrock, Andrew K.

    2013-01-01

    When extracting energy from the wind using upwind, horizontal-axis wind turbines, a primary condition for ensuring maximum power yield is the ability to align the rotor axis with the dominating wind direction. Attempts have been made to improve the yaw alignment of wind turbines by applying...... and tested. Results show that, with the correction scheme in place, the yaw alignment of the case turbine is improved and the yaw error is reduced to the vicinity of zero degrees. As a result of the improved yaw alignment, an increased power capture is observed for below-rated wind speeds....

  2. Wire number doubling in plasma-shell regime increases z-accelerator x-ray power

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, T.W.L.; Spielman, R.B.; Chandler, G.A. [and others

    1997-11-01

    Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40{+-}20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the {open_quotes}plasma shell{close_quotes} regime, where the plasmas generated by the individual wires merge prior to the inward implosion of the entire array.

  3. Effects of increased microwave heating power in the stellarator TJ-K

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, Alejandro; Koehn, Alf; Ali, Ahmed; Ramisch, Mirko [Institute of Interfacial Process Engineering and Plasma Technology, University of Stuttgart, Stuttgart (Germany)

    2015-05-01

    One of the microwave heating systems at the stellarator TJ-K has been recently upgraded: a third klystron has been installed, increasing the heating power from 4 kW to 6 kW operating at 14 GHz. A phased-array antenna is used which allows to vary the injection angle by sweeping the microwave frequency in order control the coupling mechanism of the microwave to the plasma. With the two klystrons already installed, ionization degrees of α ≅ 1 have been reached. We expect that an increased heating power, by means of the third klystron put into operation, leads to an increase in the electron temperature T{sub e} only, rather than in electron density n{sub e}, and thus a decrease in the collision frequency ν{sub ei} ∝ n{sub e}T{sub e}{sup -3/2} which has an impact on heating flow damping and neoclassical properties. Parameter scans have been performed in order to characterize the new heating scenario. A radial movable Langmuir probe has been used to obtain radial profiles of the electron density and temperature. An arrangement of bolometers and an optical diode have been used to obtain the power losses by radiation. A particle and power balance model is used to obtain estimated densities and temperatures in order to compare with the experimental results.

  4. Comparative analysis of existing models for power-grid synchronization

    Science.gov (United States)

    Nishikawa, Takashi; Motter, Adilson E.

    2015-01-01

    The dynamics of power-grid networks is becoming an increasingly active area of research within the physics and network science communities. The results from such studies are typically insightful and illustrative, but are often based on simplifying assumptions that can be either difficult to assess or not fully justified for realistic applications. Here we perform a comprehensive comparative analysis of three leading models recently used to study synchronization dynamics in power-grid networks—a fundamental problem of practical significance given that frequency synchronization of all power generators in the same interconnection is a necessary condition for a power grid to operate. We show that each of these models can be derived from first principles within a common framework based on the classical model of a generator, thereby clarifying all assumptions involved. This framework allows us to view power grids as complex networks of coupled second-order phase oscillators with both forcing and damping terms. Using simple illustrative examples, test systems, and real power-grid datasets, we study the inherent frequencies of the oscillators as well as their coupling structure, comparing across the different models. We demonstrate, in particular, that if the network structure is not homogeneous, generators with identical parameters need to be modeled as non-identical oscillators in general. We also discuss an approach to estimate the required (dynamical) system parameters that are unavailable in typical power-grid datasets, their use for computing the constants of each of the three models, and an open-source MATLAB toolbox that we provide for these computations.

  5. Improved Power Saving Mechanism to Increase Unavailability Interval in IEEE 802.16e Networks

    Science.gov (United States)

    Lee, Kyunghye; Mun, Youngsong

    To manage limited energy resources efficiently, IEEE 802.16e specifies sleep mode operation. Since there can be no communication between the mobile station (MS) and the serving base station (BS) during the unavailability interval, the MS can power down its physical operation components. We propose an improved power saving mechanism (iPSM) which effectively increases the unavailability interval of Type I and Type II power saving classes (PSCs) activated in an MS. After investigating the number of frames in the unavailability interval of each Type II PSC when used with Type I PSC, the iPSM chooses the Type II PSC that yields the maximum number of frames in the unavailability interval. Performance evaluation confirms that the proposed scheme is very effective.

  6. Increased deposition of polychlorinated biphenyls (PCBs) under an AC high-voltage power line

    Science.gov (United States)

    Öberg, Tomas; Peltola, Pasi

    2009-12-01

    There is considerable public concern regarding the potential risks to health of electromagnetic fields in general and high-voltage power lines in particular. As epidemiological findings are not supported by a clearly defined mechanism of direct magnetic field interactions with the human body, potential indirect effects are of interest. It has been suggested that an increased exposure to chemical pollutants could occur near high-voltage power lines due to formation and deposition of charged aerosols. The current study reports empirical evidence that seems to support this hypothesis. The deposition of 18 congeners of polychlorinated biphenyls (PCBs) was studied by collecting samples of pine needles under a 400 kV AC power line and at reference sites in the vicinity. Compared to the reference sites, the average deposition of PCB congeners under the power line was almost double. This difference between the two groups of samples was statistically significant. While it is premature to draw any conclusions regarding the human exposure near high-voltage power lines, the issue deserves attention and further investigations.

  7. Numerical analysis of phase change materials for thermal control of power battery of high power dissipations

    Science.gov (United States)

    Xia, X.; Zhang, H. Y.; Deng, Y. C.

    2016-08-01

    Solid-fluid phase change materials have been of increasing interest in various applications due to their high latent heat with minimum volume change. In this work, numerical analysis of phase change materials is carried out for the purpose of thermal control of the cylindrical power battery cells for applications in electric vehicles. Uniform heat density is applied at the battery cell, which is surrounded by phase change material (PCM) of paraffin wax type and contained in a metal housing. A two-dimensional geometry model is considered due to the model symmetry. The effects of power densities, heat transfer coefficients and onset melting temperatures are examined for the battery temperature evolution. Temperature plateaus can be observed from the present numerical analysis for the pure PCM cases, with the temperature level depending on the power densities, heat transfer coefficients, and melting temperatures. In addition, the copper foam of high thermal conductivity is inserted into the copper foam to enhance the heat transfer. In the modeling, the local thermal non-equilibrium between the metal foam and the PCM is taken into account and the temperatures for the metal foam and PCM are obtained respectively.

  8. Micronucleus frequency is increased in peripheral blood lymphocytes of nuclear power plant workers.

    Science.gov (United States)

    Hadjidekova, Valeria B; Bulanova, Minka; Bonassi, Stefano; Neri, Monica

    2003-12-01

    Nuclear power plant workers are exposed to ionizing radiation at relatively low doses and for prolonged periods of time. To investigate the extent of genetic damage in these workers, a group of 133 nuclear power plant workers and 39 healthy controls were compared using the cytokinesis-block micronucleus assay. The frequency of micronuclei was significantly increased in peripheral lymphocytes of nuclear power plant workers (20.5 +/- 9.7% compared to 13.7 +/- 5.9%). A significant dose-response relationship was observed between micronucleus (MN) frequency and both the accumulated dose and the duration of employment (P < 0.01 for both variables after adjusting for age, gender and cigarette smoking) with an evident leveling off for exposures over 200 mSv. Accumulated dose and duration of employment were significantly correlated but exerted independent effects on MN frequency. For non-occupational parameters, age was significantly associated with the frequency of micronuclei, while gender was not. Smoking habit showed no overall effect, whereas increased chromosome damage was evident in smokers of more than 20 cigarettes per day. In conclusion, a dose-related association between MN frequency and exposure to ionizing radiation was evident in nuclear power plant workers, encouraging the application of the cytokinesis-block micronucleus assay in biomonitoring studies of human populations with prolonged exposure to ionizing radiation.

  9. Balance Sheet and Analysis of Reactive Power Demand in the Polish Power System

    Directory of Open Access Journals (Sweden)

    Aleksander Kot

    2013-03-01

    Full Text Available The paper presents an analysis of the balance sheet and the reactive power demand of the Polish Power System. Reactive power balance sheets were made for the specific operating conditions of the system: the last winter peak, summer peak and summer off peak load. The basis of the study was load flow models and selected load flow calculation results. In addition, changes in demand for active and reactive power in recent years were presented.

  10. Analyzing the Impacts of Increased Wind Power on Generation Revenue Sufficiency

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qin; Wu, Hongyu; Tan, Jin; Hodge, Bri-Mathias; Li, Wanning; Luo, Cheng

    2016-11-14

    The Revenue Sufficiency Guarantee (RSG), as part of make-whole (or uplift) payments in electricity markets, is designed to recover the generation resources' offer-based production costs that are not otherwise covered by their market revenues. Increased penetrations of wind power will bring significant impacts to the RSG payments in the markets. However, literature related to this topic is sparse. This paper first reviews the industrial practices of implementing RSG in major U.S. independent system operators (ISOs) and regional transmission operators (RTOs) and then develops a general RSG calculation method. Finally, an 18-bus test system is adopted to demonstrate the impacts of increased wind power on RSG payments.

  11. Analyzing the Impacts of Increased Wind Power on Generation Revenue Sufficiency: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qin; Wu, Hongyu; Tan, Jin; Hodge, Bri-Mathias; Li, Wanning; Luo, Cheng

    2016-08-01

    The Revenue Sufficiency Guarantee (RSG), as part of make-whole (or uplift) payments in electricity markets, is designed to recover the generation resources' offer-based production costs that are not otherwise covered by their market revenues. Increased penetrations of wind power will bring significant impacts to the RSG payments in the markets. However, literature related to this topic is sparse. This paper first reviews the industrial practices of implementing RSG in major U.S. independent system operators (ISOs) and regional transmission operators (RTOs) and then develops a general RSG calculation method. Finally, an 18-bus test system is adopted to demonstrate the impacts of increased wind power on RSG payments.

  12. Power Consumption Analysis of Electrical Installations at Healthcare Facility

    Directory of Open Access Journals (Sweden)

    Emmanuel Guillen-Garcia

    2017-01-01

    Full Text Available This paper presents a methodology for power consumption estimation considering harmonic and interharmonic content and then it is compared to the power consumption estimation commonly done by commercial equipment based on the fundamental frequency, and how they can underestimate the power consumption considering power quality disturbances (PQD. For this purpose, data of electrical activity at the electrical distribution boards in a healthcare facility is acquired for a long time period with proprietary equipment. An analysis in the acquired current and voltage signals is done, in order to compare the power consumption centered in the fundamental frequency with the generalized definition of power consumption. The results obtained from the comparison in the power consumption estimation show differences between 4% and 10% of underestimated power consumption. Thus, it is demonstrated that the presence of harmonic and interharmonic content provokes a significant underestimation of power consumption using only the power consumption centered at the fundamental frequency.

  13. SNPSAM - Space Nuclear Power System Analysis Model

    Science.gov (United States)

    El-Genk, Mohamed S.; Seo, Jong T.

    The current version of SNPSAM is described, and the results of the integrated thermoeletric SP-100 system performance studies using SNPSAM are reported. The electric power output, conversion efficiency, coolant temperatures, and specific pumping power of the system are calculated as functions of the reactor thermal power and the liquid metal coolant type (Li or NaK-78) during steady state operation. The transient behavior of the system is also discussed.

  14. Geometrical Methods for Power Network Analysis

    CERN Document Server

    Bellucci, Stefano; Gupta, Neeraj

    2013-01-01

    This book is a short introduction to power system planning and operation using advanced geometrical methods. The approach is based on well-known insights and techniques developed in theoretical physics in the context of Riemannian manifolds. The proof of principle and robustness of this approach is examined in the context of the IEEE 5 bus system. This work addresses applied mathematicians, theoretical physicists and power engineers interested in novel mathematical approaches to power network theory.

  15. Informed conditioning on clinical covariates increases power in case-control association studies.

    Directory of Open Access Journals (Sweden)

    Noah Zaitlen

    Full Text Available Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI, smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from low-BMI cases are larger than those estimated from high-BMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals on the basis of phenotype (case-control ascertainment or phenotype and clinical covariates (case-control-covariate ascertainment. While current approaches improve power in studies with random ascertainment, they often lose power under case-control ascertainment and fail to capture available power increases under case-control-covariate ascertainment. We show that an informed conditioning approach, based on the liability threshold model with parameters informed by external epidemiological information, fully accounts for disease prevalence and non-random ascertainment of phenotype as well as covariates and provides a substantial increase in power while maintaining a properly controlled false-positive rate. Our method outperforms standard case-control association tests with or without covariates, tests of gene x covariate interaction, and previously proposed tests for dealing with covariates in ascertained data, with especially large improvements in the case of case-control-covariate ascertainment. We investigate empirical case-control studies of type 2 diabetes, prostate cancer, lung cancer, breast cancer, rheumatoid arthritis, age-related macular degeneration, and end-stage kidney disease over a total of 89,726 samples. In these datasets, informed conditioning outperforms logistic regression for 115 of the 157 known associated variants investigated (P-value = 1 × 10(-9. The improvement varied across diseases with a 16% median increase in χ(2 test statistics

  16. Informed Conditioning on Clinical Covariates Increases Power in Case-Control Association Studies

    Science.gov (United States)

    Zaitlen, Noah; Lindström, Sara; Pasaniuc, Bogdan; Cornelis, Marilyn; Genovese, Giulio; Pollack, Samuela; Barton, Anne; Bickeböller, Heike; Bowden, Donald W.; Eyre, Steve; Freedman, Barry I.; Friedman, David J.; Field, John K.; Groop, Leif; Haugen, Aage; Heinrich, Joachim; Henderson, Brian E.; Hicks, Pamela J.; Hocking, Lynne J.; Kolonel, Laurence N.; Landi, Maria Teresa; Langefeld, Carl D.; Le Marchand, Loic; Meister, Michael; Morgan, Ann W.; Raji, Olaide Y.; Risch, Angela; Rosenberger, Albert; Scherf, David; Steer, Sophia; Walshaw, Martin; Waters, Kevin M.; Wilson, Anthony G.; Wordsworth, Paul; Zienolddiny, Shanbeh; Tchetgen, Eric Tchetgen; Haiman, Christopher; Hunter, David J.; Plenge, Robert M.; Worthington, Jane; Christiani, David C.; Schaumberg, Debra A.; Chasman, Daniel I.; Altshuler, David; Voight, Benjamin; Kraft, Peter; Patterson, Nick; Price, Alkes L.

    2012-01-01

    Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI), smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from low–BMI cases are larger than those estimated from high–BMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals on the basis of phenotype (case-control ascertainment) or phenotype and clinical covariates (case-control-covariate ascertainment). While current approaches improve power in studies with random ascertainment, they often lose power under case-control ascertainment and fail to capture available power increases under case-control-covariate ascertainment. We show that an informed conditioning approach, based on the liability threshold model with parameters informed by external epidemiological information, fully accounts for disease prevalence and non-random ascertainment of phenotype as well as covariates and provides a substantial increase in power while maintaining a properly controlled false-positive rate. Our method outperforms standard case-control association tests with or without covariates, tests of gene x covariate interaction, and previously proposed tests for dealing with covariates in ascertained data, with especially large improvements in the case of case-control-covariate ascertainment. We investigate empirical case-control studies of type 2 diabetes, prostate cancer, lung cancer, breast cancer, rheumatoid arthritis, age-related macular degeneration, and end-stage kidney disease over a total of 89,726 samples. In these datasets, informed conditioning outperforms logistic regression for 115 of the 157 known associated variants investigated (P-value = 1×10−9). The improvement varied across diseases with a 16% median increase in χ2 test statistics and a

  17. Increased installation in existing hydro power plants. Potentials and costs; Oekt installasjon i eksisterende kraftverk. Potensial og kostnader

    Energy Technology Data Exchange (ETDEWEB)

    Stensby, Kjell Erik (ed.)

    2011-06-15

    This report seeks to highlight the costs associated with increased installed capacity of existing hydropower plants. Five selected power plant is further studied. Furthermore, given an overview of the technical possibilities of power expansions in Norway. (AG)

  18. Investigation into the absorptivity change in metals with increased laser power

    DEFF Research Database (Denmark)

    Blidegn, Kristian; Olsen, Flemmming Ove

    1996-01-01

    At a first glance the low absorptivity of metals in the infrared (IR) makes the use of YAG and CO2 lasers in metal processing very inefficient. However industrial inert gas cutting abilities demonstrates that the absorptivity can reach significantly higher levels during the high power laser...... interaction. An increase which can not be explained by the increase in temperature only. The interaction between laser light and metals is a major physical phenomena in laser material processing. The Drude free electron model or simplifications like the Hagen-Rubens relation has often been used to model...

  19. Investigation into the absorptivity change in Metals with increased laser Power

    DEFF Research Database (Denmark)

    Blidegn, Kristian; Olsen, Flemmming Ove

    1996-01-01

    At a first glance the low absorptivity of metals in the infrared (IR) makes the use of YAG and CO2 lasers in metal processing very inefficient. However industrial inert gas cutting abilities demonstrates that the absorptivity can reach significantly higher levels during the high power laser...... interaction. An increase which can not be explained by the increase in temperature only. The interaction between laser light and metals is a major physical phenomena in laser material processing. The Drude free electron model or simplifications like the Hagen-Rubens relation has often been used to model...

  20. Power system small signal stability analysis and control

    CERN Document Server

    Mondal, Debasish; Sengupta, Aparajita

    2014-01-01

    Power System Small Signal Stability Analysis and Control presents a detailed analysis of the problem of severe outages due to the sustained growth of small signal oscillations in modern interconnected power systems. The ever-expanding nature of power systems and the rapid upgrade to smart grid technologies call for the implementation of robust and optimal controls. Power systems that are forced to operate close to their stability limit have resulted in the use of control devices by utility companies to improve the performance of the transmission system against commonly occurring power system

  1. A New Method for Increasing Output Power of a Three-Cavity Transit-Time Oscillator

    Institute of Scientific and Technical Information of China (English)

    HE Jun-Tao; ZHONG Hui-Huang; QIAN Bao-Liang; LIU Yong-Gui

    2004-01-01

    We propose a new method to increase the output power of a three-cavity transit-time oscillator (TC-TTO).Conventional transit-time effect oscillators, such as the split-cavity oscillator (SCO), super-Reltron, and TC-TTO (or double-foil SCO), etc., have a common feature that the span of any modulating cavity is uniform. The new method is to vary the three-cavity spans from uniform to nonuniform. Its configuration is called the nonuniform three-cavity transit-time oscillator (NTC-TTO). Numerical simulations show that the electron-beam is modulated more deeply in certain NTC-TTOs than that in the TC-TTO with the same whole modulating length, and the output microwave power in certain NTC-TTOs is higher than that in the TC-TTO. The experimental results are in agreement with those of the numerical simulations. The results show that the new method can increase the output power of a microwave tube based on the TC-TTO.

  2. Prolonged menstruation and increased menstrual blood with generalized δ electroencephalogram power: A case report.

    Science.gov (United States)

    Peng, Fenghua; Zhang, Lianping

    2014-03-01

    Estradiol changes associated with the menstrual cycle have a great impact on brain activation. δ frequency mainly appears during normal sleep status or brain injury diseases, including encephalitis and mental confusion. The current case report presents a 51-year-old female with prolonged menstruation and increased menstrual blood volume whose electroencephalogram (EEG) recording demonstrated a rare generalized 3 Hz δ frequency band in the waking status. The patient had been suffering from heart palpitations and dizziness for 6 months and was receiving treatment in the Department of Neurology (Second Xiangya Hospital). The individual had been experiencing prolonged menstruation and increased menstrual blood volume for 6 years. Gynecologial examination revealed secondary anemia and hysteromyoma. Hemoglobin levels were decreased to 69 g/l. Physical and neurological examinations, and computed tomography results appeared normal. The EEG recording indicated a generalized 3 Hz δ frequency band with 30-80 μV power and a long-range δ frequency band when the patient was hyperventilating. The prolonged menstruation and increased menstrual blood volume may have induced the generalized δ frequency without brain injury. To the best of our knowledge, this is the first formal case report of prolonged menstruation and increased menstrual blood volume with the abnormality of δ EEG power.

  3. Finite Element Analysis of a Contactless Power Transformer with Metamaterial

    Directory of Open Access Journals (Sweden)

    Lan Jian Yu

    2013-07-01

    Full Text Available Wireless power transfer technologies enable power transfer to loads through air. The contactless power transformer is a key element of it. In this work, a new transformer with metamaterial is proposed, through which the power transfer distance increases. The electromagnetic properties about metamaterial are discussed at first. Then, the finite element analyses of this transformer are presented as well. The magnetic field distributions and the computational results show that this type of transformer can enlarge the power transfer range of a wireless power transfer system.

  4. Backup Power Cost of Ownership Analysis and Incumbent Technology Comparison

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, J.; Saur, G.; Sprik, S.; Ainscough, C.

    2014-09-01

    This cost of ownership analysis identifies the factors impacting the value proposition for fuel cell backup power and presents the estimated annualized cost of ownership for fuel cell backup power systems compared with the incumbent technologies of battery and diesel generator systems. The analysis compares three different backup power technologies (diesel, battery, and fuel cell) operating in similar circumstances in four run time scenarios (8, 52, 72, and 176 hours).

  5. AC Versus DC Link Comparison Based on Power Flow Analysis of a Multimachine Power System

    Directory of Open Access Journals (Sweden)

    Mohammed Abdeljalil DJEHAF

    2014-02-01

    Full Text Available Deregulation and privatization is posing new challenges on high voltage transmission and on distributions systems as well. An increasingly liberalized market will encourage trading opportunities to be identified and developed. High voltage power electronics, such as HVDC (High Voltage Direct Current and FACTS (Flexible AC Transmission Systems provide the necessary features to avoid technical problems in heavily loaded power systems; HVDC offers most advantages: it can be used for system interconnection and for control of power flow as well. The major benefit of HVDC is its incorporated ability for fault-current blocking, which is not possible with synchronous AC links. In addition, HVDC can effectively support the surrounding AC systems in case of transient fault conditions and it serves as firewall against cascading disturbances. This paper presents a comparison between HVDC link and an HVAC link in a 29 Bus multimachine system, based on load flow analysis using Newton-Raphson method for the AC link case, and sequential method for the HVDC link case.

  6. Complex Network Analysis of Brazilian Power Grid

    CERN Document Server

    Martins, Gabriela C; Ribeiro, Fabiano L; Forgerini, Fabricio L

    2016-01-01

    Power Grids and other delivery networks has been attracted some attention by the network literature last decades. Despite the Power Grids dynamics has been controlled by computer systems and human operators, the static features of this type of network can be studied and analyzed. The topology of the Brazilian Power Grid (BPG) was studied in this work. We obtained the spatial structure of the BPG from the ONS (electric systems national operator), consisting of high-voltage transmission lines, generating stations and substations. The local low-voltage substations and local power delivery as well the dynamic features of the network were neglected. We analyze the complex network of the BPG and identify the main topological information, such as the mean degree, the degree distribution, the network size and the clustering coefficient to caracterize the complex network. We also detected the critical locations on the network and, therefore, the more susceptible points to lead to a cascading failure and even to a blac...

  7. Methods for Increasing Power Efficiency of Heating Furnaces Applied in Metallurgical and Mechanical Engineering Industries

    Directory of Open Access Journals (Sweden)

    M. L. German

    2011-01-01

    Full Text Available  The paper analyzes experimental data and results of balance tests of two continuous heating furnaces applied in mechanical engineering and metallurgical industries. Furnace power technological characteristics  and dependences of these characteristics on equipment productivity have been determined in the paper. The analysis has made it possible to reveal reasons of higher efficiency of a heating furnace used at BSW Rolling Mill-320 and formulate recommendations on reduction of fuel consumption in operating and designed combustion furnaces applied in mechanical engineering and metallurgical industries.

  8. Galena Electric Power A Situational Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Robert E. Chaney; Stephen G. Colt; Ronald A. Johnson; Richard W. Wiles; Gregory J. White

    2008-12-31

    The purpose of the investigation is to compare the economics of various electrical power generation options for the City of Galena. Options were assessed over a 30-year project period, beginning in 2010, and the final results were compared on the basis of residential customer electric rates ($/kWh). Galena's electric utility currently generates power using internal combustion diesel engines and generator sets. Nearby, there is an exposed coal seam, which might provide fuel for a power plant. Contributions to the energy mix might come from solar, municipal solid waste, or wood. The City has also been approached by Toshiba, Inc., as a demonstration site for a small (Model 4S) nuclear reactor power plant. The Yukon River is possibly a site for in-river turbines for hydroelectric power. This report summarizes the comparative economics of various energy supply options. This report covers: (1) thermal and electric load profiles for Galena; (2) technologies and resources available to meet or exceed those loads; (3) uses for any extra power produced by these options; (4) environmental and permitting issues and then; and (5) the overall economics of each of the primary energy options.

  9. Exergy analysis of the FIGUEIRA thermal power plant operation - state of Parana, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Stanescu, George; Lima, Joao E. [Parana Univ., Curitiba, PR (Brazil). Dept. de Engenharia Mecanica]. E-mails: stanescu@demec.ufpr.br; joeduli@demec.ufpr.br; Andrade, Carlos de [FIGUEIRA Thermal Power Plant, Figueira, PR (Brazil)]. E-mail: ccarlosaandrade@zipmail.com.br

    2000-07-01

    Exergy analysis is a powerful tool to evaluate, design and improve the thermal systems. The method of exergy analysis or availability analysis is well suited for furthering the goal of increasing the efficiency of existing power generation systems, and the capability of more effective energy resource use. Exergy analysis of the FIGUEIRA thermal power plant is presented. Exergy losses occurring in various components are considered and the exergy balance is shown in tabular form. Results clearly reveal that the steam generator is the principal site of thermodynamic losses, while the condenser is relatively unimportant. (author)

  10. Life cycle assessment analysis of supercritical coal power units

    Science.gov (United States)

    Ziębik, Andrzej; Hoinka, Krzysztof; Liszka, Marcin

    2010-09-01

    This paper presents the Life Cycle Assessment (LCA) analysis concerning the selected options of supercritical coal power units. The investigation covers a pulverized power unit without a CCS (Carbon Capture and Storage) installation, a pulverized unit with a "post-combustion" installation (MEA type) and a pulverized power unit working in the "oxy-combustion" mode. For each variant the net electric power amounts to 600 MW. The energy component of the LCA analysis has been determined. It describes the depletion of non-renewable natural resources. The energy component is determined by the coefficient of cumulative energy consumption in the life cycle. For the calculation of the ecological component of the LCA analysis the cumulative CO2 emission has been applied. At present it is the basic emission factor for the LCA analysis of power plants. The work also presents the sensitivity analysis of calculated energy and ecological factors.

  11. Power law analysis of the human microbiome.

    Science.gov (United States)

    Ma, Zhanshan Sam

    2015-11-01

    Taylor's (1961, Nature, 189:732) power law, a power function (V = am(b) ) describing the scaling relationship between the mean and variance of population abundances of organisms, has been found to govern the population abundance distributions of single species in both space and time in macroecology. It is regarded as one of few generalities in ecology, and its parameter b has been widely applied to characterize spatial aggregation (i.e. heterogeneity) and temporal stability of single-species populations. Here, we test its applicability to bacterial populations in the human microbiome using extensive data sets generated by the US-NIH Human Microbiome Project (HMP). We further propose extending Taylor's power law from the population to the community level, and accordingly introduce four types of power-law extensions (PLEs): type I PLE for community spatial aggregation (heterogeneity), type II PLE for community temporal aggregation (stability), type III PLE for mixed-species population spatial aggregation (heterogeneity) and type IV PLE for mixed-species population temporal aggregation (stability). Our results show that fittings to the four PLEs with HMP data were statistically extremely significant and their parameters are ecologically sound, hence confirming the validity of the power law at both the population and community levels. These findings not only provide a powerful tool to characterize the aggregations of population and community in both time and space, offering important insights into community heterogeneity in space and/or stability in time, but also underscore the three general properties of power laws (scale invariance, no average and universality) and their specific manifestations in our four PLEs.

  12. Converter Power Density Increase using Low Inductive Integrated DC-link Capacitor/Bus

    DEFF Research Database (Denmark)

    Trintis, Ionut; Franke, Toke; Rannested, Bjørn;

    2015-01-01

    The power losses in switching devices have a direct effect on the maximum converter power. For a voltage source converter, the DC-link bus has a major influence on the power loss and safe operating area of the power devices. The Power Ring Film CapacitorTM integrated with an optimized bus structu...

  13. Dynamic companion harmonic circuit models for analysis of power systems with embedded power electronics devices

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, H.; Madrigal, M. [Programa de Graduados e Investigacion en Ingenieria Electrica, Instituto Tecnologico de Morelia, Morelia (Mexico); Vyakaranam, B.; Rarick, R.; Villaseca, F.E. [Department of Electrical and Computer Engineering, Cleveland State University, OH (United States)

    2011-02-15

    In this paper a methodology that extends the dynamic harmonic domain (DHD) analysis of large networks is presented. The method combines DHD analysis and discrete companion circuit modeling resulting in a powerful analytic technique called dynamic companion harmonic circuit modeling. It provides for a complete dynamic harmonic analysis of the system while preserving the advantages of discrete companion circuit models. The methodology is illustrated by its application to a three-node power system, where reactive power compensation is achieved using a fixed-capacitor, thyristor-controlled reactor (FC-TCR) and its control system. (author)

  14. Probabilistic Analysis Techniques Applied to Complex Spacecraft Power System Modeling

    Science.gov (United States)

    Hojnicki, Jeffrey S.; Rusick, Jeffrey J.

    2005-01-01

    Electric power system performance predictions are critical to spacecraft, such as the International Space Station (ISS), to ensure that sufficient power is available to support all the spacecraft s power needs. In the case of the ISS power system, analyses to date have been deterministic, meaning that each analysis produces a single-valued result for power capability because of the complexity and large size of the model. As a result, the deterministic ISS analyses did not account for the sensitivity of the power capability to uncertainties in model input variables. Over the last 10 years, the NASA Glenn Research Center has developed advanced, computationally fast, probabilistic analysis techniques and successfully applied them to large (thousands of nodes) complex structural analysis models. These same techniques were recently applied to large, complex ISS power system models. This new application enables probabilistic power analyses that account for input uncertainties and produce results that include variations caused by these uncertainties. Specifically, N&R Engineering, under contract to NASA, integrated these advanced probabilistic techniques with Glenn s internationally recognized ISS power system model, System Power Analysis for Capability Evaluation (SPACE).

  15. Cooling Tower Optimization A Simple Way to Generate Green Megawatts and to Increase the Efficiency of a Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Strohmer, F.

    2014-07-01

    The profitability of nuclear power plants is worldwide challenged by low electricity prices. One hand low cost shale gas is offering a low price electricity production , other hand additional taxes on fuel are reducing the operating income of nuclear power stations. The optimization of cooling towers can help to increase the efficiency and profit of a nuclear power plant. (Author)

  16. Increasing National Energy Mix through Carbon Sequestration of Coal for Improved Power Generation

    Directory of Open Access Journals (Sweden)

    H. U. Ugwu

    2012-12-01

    Full Text Available In this paper, a novel technology of increasing national energy mix through carbon sequestration of coal has been advocated as a panacea for improving the nation’s power generation for electricity utilization and consumption. Consequently, electricity and petroleum products which have become the energy forms relied upon in most economic sectors of the world significantly exist with some changes in time vis-à-vis the energy consumption due to changes in the structure of the economy, energy prices, level of production of goods and services, technology and population, etc. Also, the exclusive dependence on income from oil for infrastructural development thus became the order of the day. These, are considered unsustainable especially with the total neglect of the agrarian nature of the country and the unproductive capabilities of other goods and services derivable from electricity generated. Hence, these seriously portend that urgent and drastic engineering strategies must be introduced in the energy sector to revamp the dwindling power generation. Thus, carbon sequestration of coal is the suggested option as a clean coal energy technology for power plant optimization. In this study, some air-dried Nigerian coals collected from different coal deposits across the country were utilized for the analyses to investigate their characteristics and rheology. The result obtained shows that chemically re-characterized Enugu sub-bituminous air dried coal has the highest carbon content ranging from 3.8% to 46.27% while its calorific value was found to be also high among others at the range of 22.3 to 28.4MJ/Kg, respectively. The result also shows that increase in carbon contents for all the coal samples resulted to increase in calorific value which would reduce the accumulation of greenhouse gases in the atmosphere if released by the burning of these fossil fuels. The technology of a good sequestered carbon if adopted will help in revamping the dwindling

  17. A navigation system for increasing the autonomy and the security of powered wheelchairs.

    Science.gov (United States)

    Fioretti, S; Leo, T; Longhi, S

    2000-12-01

    Assistive technology is an emerging area where some robotic devices can be used to strengthen the residual abilities of individuals with motor disabilities or to substitute their missing function thus helping them to gain a level of independence at least in the activities of daily living. This paper presents the design of a navigation system and its integration with a commercial powered wheelchair. The navigation system provides the commercial wheelchair with a set of functions which increase the autonomy of elderly and people with motor disabilities. In general, a robot device must be adapted to assistive applications in such a way as to be easily managed by the user. Users, especially young ones, prefer to directly control the robotic device and this aspect of usability has to be managed without affecting the security and efficiency of the navigation module. These aspects have been considered as specifications for the navigation module of powered wheelchairs. Different autonomy levels of the navigation module and proper user interfaces have been developed. Two autonomy levels have been designed. Simple collision avoidance is also implemented in order to stop the mobile base when an obstacle is detected. The preliminary technical tests performed on the navigation system have shown satisfactory results in terms of security and response time. A modular solution for the navigation module was considered in order to simplify the adaptation of the module to different powered wheelchairs.

  18. Stability analysis of spacecraft power systems

    Science.gov (United States)

    Halpin, S. M.; Grigsby, L. L.; Sheble, G. B.; Nelms, R. M.

    1990-01-01

    The problems in applying standard electric utility models, analyses, and algorithms to the study of the stability of spacecraft power conditioning and distribution systems are discussed. Both single-phase and three-phase systems are considered. Of particular concern are the load and generator models that are used in terrestrial power system studies, as well as the standard assumptions of load and topological balance that lead to the use of the positive sequence network. The standard assumptions regarding relative speeds of subsystem dynamic responses that are made in the classical transient stability algorithm, which forms the backbone of utility-based studies, are examined. The applicability of these assumptions to a spacecraft power system stability study is discussed in detail. In addition to the classical indirect method, the applicability of Liapunov's direct methods to the stability determination of spacecraft power systems is discussed. It is pointed out that while the proposed method uses a solution process similar to the classical algorithm, the models used for the sources, loads, and networks are, in general, more accurate. Some preliminary results are given for a linear-graph, state-variable-based modeling approach to the study of the stability of space-based power distribution networks.

  19. Increase in Organization Effectiveness Using Voice Analysis: The System Approach

    Directory of Open Access Journals (Sweden)

    Lina Bartkienė

    2011-04-01

    Full Text Available The main purpose of this article is to analyze literature related to the system theory and to present the system of increase in organization effectiveness using voice analysis. The concepts of the system approach were analyzed, the definition of the system, its components and classification were discussed. Following the principles of the system theory, the system of increase in organization effectiveness using voice analysis was designed. Each element was briefly discussed, i.e. processes influencing the employee, the environment, voice analysis system, expert system, prime and final organizational effectiveness. In addition, the relations between these elements were indentified. Article in Lithuanian

  20. Power spectrum analysis for optical tweezers

    DEFF Research Database (Denmark)

    Berg-Sørensen, K.; Flyvbjerg, H.

    2004-01-01

    The force exerted by an optical trap on a dielectric bead in a fluid is often found by fitting a Lorentzian to the power spectrum of Brownian motion of the bead in the trap. We present explicit functions of the experimental power spectrum that give the values of the parameters fitted, including...... error bars and correlations, for the best such chi(2) fit in a given frequency range. We use these functions to determine the information content of various parts of the power spectrum, and find, at odds with lore, much information at relatively high frequencies. Applying the method to real data, we...... the Lorentzian provides. This is achieved using old and new theory for Brownian motion in an incompressible fluid, and new results for a popular photodetection system. The trap and photodetection system are then calibrated simultaneously in a manner that makes optical tweezers a tool of precision for force...

  1. Thermodynamic analysis of a FBCC steam power plant

    Energy Technology Data Exchange (ETDEWEB)

    Eskin, Nurdil; Oezdemir, Koray [Faculty of Mechanical Engineering, Istanbul Technical Univ., 34437 Istanbul (Turkey); Gungor, Afsin [Dept. of Mechanical Engineering, Faculty of Engineering and Architecture, Nigde Univ., 51100 Nigde (Turkey)

    2009-09-15

    This article presents the analysis of first and second laws of thermodynamics in a 7.7 MW steam power plant located in Torbali (Izmir, Turkey). It involves a fluidized bed, a waste heat boiler (WHB) and an economizer as subsystems. Fans, pumps, cyclone and chimney are also considered through the analysis as auxiliary systems in the thermal plant. The analysis is performed for the whole system and subsystems by considering the available energy balance. In this analysis which consists of a detailed fluidized bed coal combustor (FBCC) model, the amount of irreversibilities occurring in the system is calculated at each location. Analysis results are compared with the test results obtained from the measurements at several locations in the system and good agreement is observed. These measured values are the temperatures at three levels in the FBCC and boiler, economizer exit temperatures as well as flue gas composition at the boiler exit and steam flow rate. The maximum error observed in temperature values and steam flow rate is about 3.03% and 4.03%, respectively. Through the developed and validated model, effects of excess air and ambient temperature on first and second law efficiency of the subsystems and overall system are investigated. The second-law analysis reveals that the FBCC has the largest irreversibility, with about 80.4% of the total system exergy loss. The FBCC temperature, first and second law efficiencies decrease 19.8%, 5.1% and 5.2%, respectively, as the excess air increases from 10% to 70%. Also steam flow rate decreases 5.1%. As the ambient temperature increases from 25 to 45 C, the FBCC temperature, system first and second law efficiencies increase 0.8%, 1.3%, and 1.3%, respectively. (author)

  2. Power Processing, Part 1. Electric Machinery Analysis.

    Science.gov (United States)

    Hamilton, Howard B.

    This publication was developed as a portion of a two-semester sequence commencing at either the sixth or seventh term of the undergraduate program in electrical engineering at the University of Pittsburgh. The materials of the two courses, produced by a National Science Foundation grant, are concerned with power conversion systems comprising power…

  3. SELECTIVE MODAL ANALYSIS OF POWER FLOW OSCILLATION IN LARGE SCALE LONGITUDINAL POWER SYSTEMS

    Directory of Open Access Journals (Sweden)

    Wirindi -

    2009-06-01

    Full Text Available Novel selective modal analysis for the determination of low frequency power flow oscillation behaviour based on eigenvalues with corresponding damping ratio, cumulative damping index, and participation factors is proposed. The power system being investigated consists of three large longitudinally interconnected areas with some weak tie lines. Different modes, such as exciter modes, inter area modes, and local modes of the dominant poles are fully studied to find out the significant level of system damping and other factors producing power flow instability. The nature of the energy exchange between area is determined and strategic power flow stability improvement is developed and tested.

  4. Biomechanical analysis of the muscular power of martial arts athletes.

    Science.gov (United States)

    Machado, S M; Osório, R A L; Silva, N S; Magini, M

    2010-06-01

    This study analyzes the performance of knee extension and flexion of Taekwondo and Kickboxing athletes. The power values were extracted through electromyography obtained by an isokinetic dynamometer at 60 degrees per second. These values are resulted from the square of the electromyography signal. The analysis of kick power was made using a modified wavelet algorithm considering values with 95% significance. Both groups presented equivalent power and torque capacity with different training times and experience, on the other hand, the wavelet analysis showed better results in muscular recruitment performance in athletes with more experience, in other words, power is not only performance but also power plus recruitment produces better results. This study uniquely showed that muscular enhancement capacity is not only related to the power capacity of contraction but also to motor coordination.

  5. Profitable increases in cross border transmission capacities in a European power system with large shares of renewables

    Energy Technology Data Exchange (ETDEWEB)

    Graabak, Ingeborg; Wolfgang, Ove

    2012-07-01

    This report describes analyses of profitable increases in cross border capacities in Europe in a time perspective 2030-2050 for situations with large shares of renewables in the power system. The analysis reuses a lot of the methodology from the EU 7th Framework Programme project SUSPLAN. The analyses use the EMPS model (a European model for multi-area power market simulations) and a new investment algorithm on four scenarios Red (40.1 % RES-E in 2050, traditional technologies), Yellow (54 % RES-E in 2050, traditional technologies + extra PV), Green (69 % RES-E in 2050, mainly local and regional production) and Blue (72 % RES-E in 2050, large scale production far away from demand centers). The analyses show that for the four scenarios considerable increases in cross border connections will be necessary. The capacities are in all scenarios more than doubled in 2050 compared to the system in 2010 based on profitability criteria. The result varies from about 120 000 MW in new capacities to as much as 712 700 MW dependent on the volume and location of the new renewables. The increase of transmission capacities is much higher in Blue than in the other scenarios. Blue is dominated by large scale offshore wind production and import of solar based production from Africa. The Green has the lowest CO{sub 2} emissions, a secure electricity system and the lowest electricity prices. High investments are required, but they are limited compared to a future like Blue. (Author)

  6. Analysis of Facial Injuries Caused by Power Tools.

    Science.gov (United States)

    Kim, Jiye; Choi, Jin-Hee; Hyun Kim, Oh; Won Kim, Sug

    2016-06-01

    The number of injuries caused by power tools is steadily increasing as more domestic woodwork is undertaken and more power tools are used recreationally. The injuries caused by the different power tools as a consequence of accidents are an issue, because they can lead to substantial costs for patients and the national insurance system. The increase in hand surgery as a consequence of the use of power tools and its economic impact, and the characteristics of the hand injuries caused by power saws have been described. In recent years, the authors have noticed that, in addition to hand injuries, facial injuries caused by power tools commonly present to the emergency room. This study aimed to review the data in relation to facial injuries caused by power saws that were gathered from patients who visited the trauma center at our hospital over the last 4 years, and to analyze the incidence and epidemiology of the facial injuries caused by power saws. The authors found that facial injuries caused by power tools have risen continually. Facial injuries caused by power tools are accidental, and they cause permanent facial disfigurements and functional disabilities. Accidents are almost inevitable in particular workplaces; however, most facial injuries could be avoided by providing sufficient operator training and by tool operators wearing suitable protective devices. The evaluation of the epidemiology and patterns of facial injuries caused by power tools in this study should provide the information required to reduce the number of accidental injuries.

  7. Characteristic Analysis and Design of Power Flow of Organizations

    Institute of Scientific and Technical Information of China (English)

    YonganZhang; HuaLiang

    2004-01-01

    This thesis has carried on comparative analysis to the power characteristic of 5 kinds of institutional framework of enterprises at first, and has carried on the survey to the domestic and international train of thought in the research about enterprise's power, then puts forward the basic contradiction in enterprises organization ("The contradictions of the complexity of management's target and people's limited reason") and essential feature ofcurrent enterprise's power ("Solidification of power"), and then has put forward new train of thought in the study of enterprise's power and organization ("flow of power"), finally has designed the way and direction that the power flowed in enterprises, Combining enterprise's life cycle theory and American scholar L.E.Greiner's model about organization development.

  8. Router Power Consumption Analysis: Towards Green Communications

    OpenAIRE

    ANDRADE MORELLI, SEBASTIÁN; RUIZ SANCHEZ, EDUARDO; Sendra, Sandra; Lloret, Jaime

    2013-01-01

    2nd International Conference on Green Communications and Networking, GreeNets 2012; Gandia; Spain; 25 October 2012 through 26 October 2012 In recent years, the number of network devices which are being used in new network infrastructure and intelligent buildings, are growing more and more. Because these devices can often have high processing activity, we must consider their power consumption. Their energy requirements may vary depending on their operation mode, their processing capacity an...

  9. Power distribution and performance analysis for wireless communication networks

    CERN Document Server

    Zhao, Dongmei

    2012-01-01

    This book provides an analysis of transmission power and network performance in different wireless communication networks. It presents the latest research and techniques for power and interference control and performance modeling in wireless communication networks with different network topologies, air interfaces, and transmission techniques. While studying the power distributions and resource management, the reader will also learn basic methodology and skills for problem formulations, can ascertain the complexity for designing radio resource management strategies in modern wireless communicat

  10. Building 865 Hypersonic Wind Tunnel Power System Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Larry X. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    This report documents the characterization and analysis of a high current power supply for the building 865 Hypersonic Wind Tunnel at Sandia National Laboratories. The system described in this report became operational in 2013, replacing the original 1968 system which employed an induction voltage regulator. This analysis and testing was completed to help the parent organization understand why an updated and redesigned power system was not delivering adequate power to resistive heater elements in the HWT. This analysis led to an improved understanding of the design and operation of the revised 2013 power supply system and identifies several reasons the revised system failed to achieve the performance of the original power supply installation. Design modifications to improve the performance of this system are discussed.

  11. PowerPlay: Training an Increasingly General Problem Solver by Continually Searching for the Simplest Still Unsolvable Problem.

    Science.gov (United States)

    Schmidhuber, Jürgen

    2013-01-01

    Most of computer science focuses on automatically solving given computational problems. I focus on automatically inventing or discovering problems in a way inspired by the playful behavior of animals and humans, to train a more and more general problem solver from scratch in an unsupervised fashion. Consider the infinite set of all computable descriptions of tasks with possibly computable solutions. Given a general problem-solving architecture, at any given time, the novel algorithmic framework PowerPlay (Schmidhuber, 2011) searches the space of possible pairs of new tasks and modifications of the current problem solver, until it finds a more powerful problem solver that provably solves all previously learned tasks plus the new one, while the unmodified predecessor does not. Newly invented tasks may require to achieve a wow-effect by making previously learned skills more efficient such that they require less time and space. New skills may (partially) re-use previously learned skills. The greedy search of typical PowerPlay variants uses time-optimal program search to order candidate pairs of tasks and solver modifications by their conditional computational (time and space) complexity, given the stored experience so far. The new task and its corresponding task-solving skill are those first found and validated. This biases the search toward pairs that can be described compactly and validated quickly. The computational costs of validating new tasks need not grow with task repertoire size. Standard problem solver architectures of personal computers or neural networks tend to generalize by solving numerous tasks outside the self-invented training set; PowerPlay's ongoing search for novelty keeps breaking the generalization abilities of its present solver. This is related to Gödel's sequence of increasingly powerful formal theories based on adding formerly unprovable statements to the axioms without affecting previously provable theorems. The continually increasing

  12. Performance and stability analysis of a photovoltaic power system

    Science.gov (United States)

    Merrill, W. C.; Blaha, R. J.; Pickrell, R. L.

    1978-01-01

    The performance and stability characteristics of a 10 kVA photovoltaic power system are studied using linear Bode analysis and a nonlinear analog simulation. Power conversion efficiencies, system stability, and system transient performance results are given for system operation at various levels of solar insolation. Additionally, system operation and the modeling of system components for the purpose of computer simulation are described.

  13. Integrated analysis software for bulk power system stability

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Nagao, T.; Takahashi, K. [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1994-12-31

    This paper presents Central Research Inst.of Electric Power Industry - CRIEPI`s - own developed three softwares for bulk power network analysis and the user support system which arranges tremendous data necessary for these softwares with easy and high reliability. (author) 3 refs., 7 figs., 2 tabs.

  14. Power Analysis in Two-Level Unbalanced Designs

    Science.gov (United States)

    Konstantopoulos, Spyros

    2010-01-01

    Previous work on statistical power has discussed mainly single-level designs or 2-level balanced designs with random effects. Although balanced experiments are common, in practice balance cannot always be achieved. Work on class size is one example of unbalanced designs. This study provides methods for power analysis in 2-level unbalanced designs…

  15. Event-scale power law recession analysis: quantifying methodological uncertainty

    Science.gov (United States)

    Dralle, David N.; Karst, Nathaniel J.; Charalampous, Kyriakos; Veenstra, Andrew; Thompson, Sally E.

    2017-01-01

    The study of single streamflow recession events is receiving increasing attention following the presentation of novel theoretical explanations for the emergence of power law forms of the recession relationship, and drivers of its variability. Individually characterizing streamflow recessions often involves describing the similarities and differences between model parameters fitted to each recession time series. Significant methodological sensitivity has been identified in the fitting and parameterization of models that describe populations of many recessions, but the dependence of estimated model parameters on methodological choices has not been evaluated for event-by-event forms of analysis. Here, we use daily streamflow data from 16 catchments in northern California and southern Oregon to investigate how combinations of commonly used streamflow recession definitions and fitting techniques impact parameter estimates of a widely used power law recession model. Results are relevant to watersheds that are relatively steep, forested, and rain-dominated. The highly seasonal mediterranean climate of northern California and southern Oregon ensures study catchments explore a wide range of recession behaviors and wetness states, ideal for a sensitivity analysis. In such catchments, we show the following: (i) methodological decisions, including ones that have received little attention in the literature, can impact parameter value estimates and model goodness of fit; (ii) the central tendencies of event-scale recession parameter probability distributions are largely robust to methodological choices, in the sense that differing methods rank catchments similarly according to the medians of these distributions; (iii) recession parameter distributions are method-dependent, but roughly catchment-independent, such that changing the choices made about a particular method affects a given parameter in similar ways across most catchments; and (iv) the observed correlative relationship

  16. THE TECHNOLOGICAL AND EXPLOITATIVE FACTORS OF LOCAL INCREASE OF ELECTRIC FIELD STRENGTH IN THE POWER CABLE OF COAXIAL DESIGN

    Directory of Open Access Journals (Sweden)

    G. V. Bezprozvannych

    2016-12-01

    Full Text Available Introduction. Reliability of high voltage power cables in the process of long-term operation is largely due to the intensity of polymeric insulation aging. It is now established that the aging of polyethylene, which is the main material for the insulation of high voltage power cables, under the action of the electric field is determined primarily by the presence of structural heterogeneity arising both during cable production and during use. The cable is always there deviations from the ideal structure, which manifest in a deviation of diameters of conductors from nominal values; in the arrangement of the conductor and the insulation is not strictly coaxially and eccentrically; in elliptic (oval core and insulation; change in relative dielectric constant and thickness of insulation on cable length force the formation of low molecular weight products (including water in the flow at the manufacturing stage crosslinked polyethylene insulation and moisture during operation. Such defects are structural, technological and operational irregularities, which lead to a local change in the electric field. Purpose. Analysis of the influence of the eccentricity, elliptic and spherical inclusions in the electric field distribution in the power cable of a coaxial design with cross-linked polyethylene insulation, based on numerical simulation. Methodology. The bases of the numerical method of calculation of the electrical field strength are Fredholm integral equations of the first and second kind (method of secondary sources for an axially symmetric field. Analysis of the influence of irregularities, including water treeing, the shape of the sounding signal is made using the method of discrete resistive circuit inductance and capacitance of substitution with the initial conditions. Solving systems of linear algebraic equations nodal analysis performed by the sweep method. Results. The presence of the eccentricity and ellipticity in the construction of cable has

  17. Power analysis for genome-wide association studies

    Directory of Open Access Journals (Sweden)

    Klein Robert J

    2007-08-01

    Full Text Available Abstract Background Genome-wide association studies are a promising new tool for deciphering the genetics of complex diseases. To choose the proper sample size and genotyping platform for such studies, power calculations that take into account genetic model, tag SNP selection, and the population of interest are required. Results The power of genome-wide association studies can be computed using a set of tag SNPs and a large number of genotyped SNPs in a representative population, such as available through the HapMap project. As expected, power increases with increasing sample size and effect size. Power also depends on the tag SNPs selected. In some cases, more power is obtained by genotyping more individuals at fewer SNPs than fewer individuals at more SNPs. Conclusion Genome-wide association studies should be designed thoughtfully, with the choice of genotyping platform and sample size being determined from careful power calculations.

  18. Randomized block experimental designs can increase the power and reproducibility of laboratory animal experiments.

    Science.gov (United States)

    Festing, Michael F W

    2014-01-01

    Randomized block experimental designs have been widely used in agricultural and industrial research for many decades. Usually they are more powerful, have higher external validity, are less subject to bias, and produce more reproducible results than the completely randomized designs typically used in research involving laboratory animals. Reproducibility can be further increased by using time as a blocking factor. These benefits can be achieved at no extra cost. A small experiment investigating the effect of an antioxidant on the activity of a liver enzyme in four inbred mouse strains, which had two replications (blocks) separated by a period of two months, illustrates this approach. The widespread failure to use these designs more widely in research involving laboratory animals has probably led to a substantial waste of animals, money, and scientific resources and slowed down the development of new treatments for human and animal diseases.

  19. Practical application of the benchmarking technique to increase reliability and efficiency of power installations and main heat-mechanic equipment of thermal power plants

    Science.gov (United States)

    Rimov, A. A.; Chukanova, T. I.; Trofimov, Yu. V.

    2016-12-01

    Data on the comparative analysis variants of the quality of power installations (benchmarking) applied in the power industry is systematized. It is shown that the most efficient variant of implementation of the benchmarking technique is the analysis of statistical distributions of the indicators in the composed homogenous group of the uniform power installations. The benchmarking technique aimed at revealing the available reserves on improvement of the reliability and heat efficiency indicators of the power installations of the thermal power plants is developed in the furtherance of this approach. The technique provides a possibility of reliable comparison of the quality of the power installations in their homogenous group limited by the number and adoption of the adequate decision on improving some or other technical characteristics of this power installation. The technique provides structuring of the list of the comparison indicators and internal factors affecting them represented according to the requirements of the sectoral standards and taking into account the price formation characteristics in the Russian power industry. The mentioned structuring ensures traceability of the reasons of deviation of the internal influencing factors from the specified values. The starting point for further detail analysis of the delay of the certain power installation indicators from the best practice expressed in the specific money equivalent is positioning of this power installation on distribution of the key indicator being a convolution of the comparison indicators. The distribution of the key indicator is simulated by the Monte-Carlo method after receiving the actual distributions of the comparison indicators: specific lost profit due to the short supply of electric energy and short delivery of power, specific cost of losses due to the nonoptimal expenditures for repairs, and specific cost of excess fuel equivalent consumption. The quality loss indicators are developed

  20. Increased mortality rate and suicide in Swedish former elite male athletes in power sports.

    Science.gov (United States)

    Lindqvist, A-S; Moberg, T; Ehrnborg, C; Eriksson, B O; Fahlke, C; Rosén, T

    2014-12-01

    Physical training has been shown to reduce mortality in normal subjects, and athletes have a healthier lifestyle after their active career as compared with normal subjects. Since the 1950s, the use of anabolic androgenic steroids (AAS) has been frequent, especially in power sports. The aim of the present study was to investigate mortality, including causes of death, in former Swedish male elite athletes, active 1960-1979, in wrestling, powerlifting, Olympic lifting, and the throwing events in track and field when the suspicion of former AAS use was high. Results indicate that, during the age period of 20-50 years, there was an excess mortality of around 45%. However, when analyzing the total study period, the mortality was not increased. Mortality from suicide was increased 2-4 times among the former athletes during the period of 30-50 years of age compared with the general population of men. Mortality rate from malignancy was lower among the athletes. As the use of AAS was marked between 1960 and 1979 and was not doping-listed until 1975, it seems probable that the effect of AAS use might play a part in the observed increased mortality and suicide rate. The otherwise healthy lifestyle among the athletes might explain the low malignancy rates.

  1. Electric Power quality Analysis in research reactor: Impacts on nuclear safety assessment and electrical distribution reliability

    Energy Technology Data Exchange (ETDEWEB)

    Touati, Said; Chennai, Salim; Souli, Aissa [Nuclear Research Centre of Birine, Ain Oussera, Djelfa Province (Algeria)

    2015-07-01

    The increased requirements on supervision, control, and performance in modern power systems make power quality monitoring a common practise for utilities. Large databases are created and automatic processing of the data is required for fast and effective use of the available information. Aim of the work presented in this paper is the development of tools for analysis of monitoring power quality data and in particular measurements of voltage and currents in various level of electrical power distribution. The study is extended to evaluate the reliability of the electrical system in nuclear plant. Power Quality is a measure of how well a system supports reliable operation of its loads. A power disturbance or event can involve voltage, current, or frequency. Power disturbances can originate in consumer power systems, consumer loads, or the utility. The effect of power quality problems is the loss power supply leading to severe damage to equipments. So, we try to track and improve system reliability. The assessment can be focused on the study of impact of short circuits on the system, harmonics distortion, power factor improvement and effects of transient disturbances on the Electrical System during motor starting and power system fault conditions. We focus also on the review of the Electrical System design against the Nuclear Directorate Safety Assessment principles, including those extended during the last Fukushima nuclear accident. The simplified configuration of the required system can be extended from this simple scheme. To achieve these studies, we have used a demo ETAP power station software for several simulations. (authors)

  2. Toward optimal cluster power spectrum analysis

    CERN Document Server

    Smith, Robert E

    2014-01-01

    The power spectrum of galaxy clusters is an important probe of the cosmological model. In this paper we determine the optimal weighting scheme for maximizing the signal-to-noise ratio for such measurements. We find a closed form analytic expression for the optimal weights. Our expression takes into account: cluster mass, finite survey volume effects, survey masking, and a flux limit. The implementation of this weighting scheme requires knowledge of the measured cluster masses, and analytic models for the bias and space-density of clusters as a function of mass and redshift. Recent studies have suggested that the optimal method for reconstruction of the matter density field from a set of clusters is mass-weighting (Seljak et al 2009, Hamaus et al 2010, Cai et al 2011). We compare our optimal weighting scheme with this approach and also with the original power spectrum scheme of Feldman et al (1994). We show that our optimal weighting scheme outperforms these approaches for both volume- and flux-limited cluster...

  3. Flux analysis in plant metabolic networks: increasing throughput and coverage.

    Science.gov (United States)

    Junker, Björn H

    2014-04-01

    Quantitative information about metabolic networks has been mainly obtained at the level of metabolite contents, transcript abundance, and enzyme activities. However, the active process of metabolism is represented by the flow of matter through the pathways. These metabolic fluxes can be predicted by Flux Balance Analysis or determined experimentally by (13)C-Metabolic Flux Analysis. These relatively complicated and time-consuming methods have recently seen significant improvements at the level of coverage and throughput. Metabolic models have developed from single cell models into whole-organism dynamic models. Advances in lab automation and data handling have significantly increased the throughput of flux measurements. This review summarizes advances to increase coverage and throughput of metabolic flux analysis in plants.

  4. Design And Analysis Of Low Power Hierarchical Decoder

    Directory of Open Access Journals (Sweden)

    Abhinav Singh

    2012-11-01

    Full Text Available Due to the high degree of miniaturization possible today in semiconductor technology, the size and complexity of designs that may be implemented in hardware has increased dramatically. Process scaling has been used in the miniaturization process to reduce the area needed for logic functions in an effort to lower the product costs. Precharged Complementary Metal Oxide Semiconductor (CMOS domino logic techniques may be applied to functional blocks to reduce power. Domino logic forms an attractive design style for high performance designs since its low switching threshold and reduced transistor count leads to fast and area efficient circuit implementations. In this paper all the necessary components required to form a 5-to-32 bit decoder using domino logic are designed to perform different analysis at 180nm & 350 nm technologies. Decoderimplemented through domino logic is compared to static decoder.

  5. Windfarm generation assessment for reliability analysis of power systems

    DEFF Research Database (Denmark)

    Negra, N.B.; Holmstrøm, O.; Bak-Jensen, B.;

    2007-01-01

    Due to the fast development of wind generation in the past ten years, increasing interest has been paid to techniques for assessing different aspects of power systems with a large amount of installed wind generation. One of these aspects concerns power system reliability. Windfarm modelling plays...

  6. Extending the lifetime of power electronic assemblies by increased cooling temperatures

    OpenAIRE

    Hutzler, Aaron; Tokarski, Adam; Schletz, Andreas

    2013-01-01

    The lifetime of power electronic modules can be assessed by an active power cycling test. The results are often compared to empirical (e.g. LESIT) and physical lifetime models (e.g. Suhir). During the last years new device technologies, such as silver-sintering instead of soldering and SiC instead of Si semiconductors, found their way into power electronics. For the evaluation of lifetime prediction models for assemblies with these new technologies, power cycling tests were performed. Thereby...

  7. Utilization of graph theory in security analysis of power grid

    Directory of Open Access Journals (Sweden)

    Dalibor Válek

    2014-12-01

    Full Text Available This paper describes way how to use graph theory in security analysis. As an environment is used network of power lines and devices which are included here. Power grid is considered as a system of nodes which make together graph (network. On the simple example is applied Fiedler´s theory which is able to select the most important power lines of whole network. Components related to these lines are logicly ordered and considered by author´s modified analysis. This method has been improved and optimalized for risks related with illegal acts. Each power grid component has been connected with possible kind of attack and every of this device was gradually evaluated by five coefficients which takes values from 1 to 10. On the coefficient basis was assessed the level of risk. In the last phase the most risky power grid components have been selected. On the selected devices have been proposed security measures.

  8. Determination of the potential for utilising combined heat and power and of the target reduction of CO{sub 2} emissions, inclusive of cost analysis (increased use of combined heat and power); Ermittlung der Potenziale fuer die Anwendung der Kraft-Waerme-Kopplung und der erzielbaren Minderung der CO{sub 2}-Emissionen einschliesslich Bewertung der Kosten (Verstaerkte Nutzung der Kraft-Waerme-Kopplung)

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Manfred; Ziesing, Hans-Joachim [Deutsches Inst. fuer Wirtschaftsforschung, Berlin (Germany); Matthes, Felix Christian; Harthan, Ralph [Oeko Institut e.V., Berlin (Germany); Menzler, Gerald [VIK Verband der Industriellen Energie- und Kraftwirtschaft e.V., Essen (Germany)

    2007-07-15

    The report provides a statistical overview of CHP utilisation up to now in Germany, analyses the general economic and political conditions with a view to evaluating the competitiveness of CHP, discusses the effectiveness of the German CHP Act with respect to its contribution to meeting emissions-related goals, analyses the cost-effectiveness of investments in different types of new CHP installations, addresses mid- and longer term potential as well as impediments to the utilisation of CHP installations, presents model simulations of how CHP is expected to develop in the context of economic conditions subject to various general political conditions and makes recommendations with an eye to additional requirements and opportunities to support CHP, against the background of the findings of the analysis. (orig.)

  9. Improving packaging and increasing the level of integration in power electronics

    NARCIS (Netherlands)

    Popovic, J.

    2005-01-01

    The use of power electronics is growing extensively in applications such as the automotive field, lighting, power supplies, motor drives, etc. The ultimate goal is to make power electronics as transparent to the final user as possible, which means little extra cost, use of existing space and little

  10. THERMODYNAMIC ANALYSIS OF CARBON SEQUESTRATION METHODS IN LIGNITE POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Koroneos J. Christopher; Sakiltzis Christos; Rovas C. Dimitrios [Laboratory of Heat Transfer and Environmental Engineering, Department of Mechanical Engineering, Aristotle University of Thessaloniki, Thessaloniki (Greece)

    2008-09-30

    The green house effect is a very pressing issue of our times due to the big impact it will have in the future of life in our planet. The temperature increase of the earth which is the major impact of the greenhouse effect may change forever the climate and the way of life in many countries. It may lead to the reduction of agricultural production and at the end to famine, in several nations. The minimization of CO2 emissions and the introduction of new energy sources is the only solution to the catastrophe that is coming if inaction prevails. The objective of this work is to analyze the methods of the CO2 removal from the flue gases of power plants that use solid fuels. It is especially fit to the Greek conditions where the main fuel used is lignite. Three methods have been examined and compared thermodynamically. These are: (a) Removal of CO2 from the flue gas stream by absorption, (b) The combustion of lignite with pure oxygen and (c) The gasification of lignite. The lignite used in the analysis is the Greek lignite, produced at the Western Macedonia mines. The power plant, before carbon sequestration, has an efficiency of 39%, producing 330MW of electric power. After sequestration, the CO2 is compressed to pressures between 80-110 atm, before its final disposal. In the first method, the sequestration of CO2 is done utilizing a catalyst. The operation requires electricity and high thermal load which is received from low pressure steam extracted from the turbines. Additionally, electricity is required for the compression of the CO2 to 100 bars. This leads to a lower efficiency of the power plant by by 13%. In the second method, the lignite combustion is done with pure O2 produced at an air separation unit. The flue gasses are made up of CO2 and water vapor. This method requires electricity for carbon dioxide compression and the Air Separation unit, thus, the power plant efficiency is lowered by 26%. In the lignite gasification method, the products are a mixture of

  11. Nitrogen-Based Fuels: A Power-to-Fuel-to-Power Analysis.

    Science.gov (United States)

    Grinberg Dana, Alon; Elishav, Oren; Bardow, André; Shter, Gennady E; Grader, Gideon S

    2016-07-25

    What are the fuels of the future? Seven representative carbon- and nitrogen-based fuels are evaluated on an energy basis in a power-to-fuel-to-power analysis as possible future chemical hydrogen-storage media. It is intriguing to consider that a nitrogen economy, where hydrogen obtained from water splitting is chemically stored on abundant nitrogen in the form of a nontoxic and safe nitrogen-based alternative fuel, is energetically feasible.

  12. Thermoeconomic Analysis of Hybrid Power Plant Concepts for Geothermal Combined Heat and Power Generation

    OpenAIRE

    Florian Heberle; Dieter Brüggemann

    2014-01-01

    We present a thermo-economic analysis for a low-temperature Organic Rankine Cycle (ORC) in a combined heat and power generation (CHP) case. For the hybrid power plant, thermal energy input is provided by a geothermal resource coupled with the exhaust gases of a biogas engine. A comparison to alternative geothermal CHP concepts is performed by considering variable parameters like ORC working fluid, supply temperature of the heating network or geothermal water temperature. Second law efficiency...

  13. Power system stability modelling, analysis and control

    CERN Document Server

    Sallam, Abdelhay A

    2015-01-01

    This book provides a comprehensive treatment of the subject from both a physical and mathematical perspective and covers a range of topics including modelling, computation of load flow in the transmission grid, stability analysis under both steady-state and disturbed conditions, and appropriate controls to enhance stability.

  14. Thermoeconomic Analysis of Hybrid Power Plant Concepts for Geothermal Combined Heat and Power Generation

    Directory of Open Access Journals (Sweden)

    Florian Heberle

    2014-07-01

    Full Text Available We present a thermo-economic analysis for a low-temperature Organic Rankine Cycle (ORC in a combined heat and power generation (CHP case. For the hybrid power plant, thermal energy input is provided by a geothermal resource coupled with the exhaust gases of a biogas engine. A comparison to alternative geothermal CHP concepts is performed by considering variable parameters like ORC working fluid, supply temperature of the heating network or geothermal water temperature. Second law efficiency as well as economic parameters show that hybrid power plants are more efficient compared to conventional CHP concepts or separate use of the energy sources.

  15. Deconstructing the power resistance relationship for squats: A joint-level analysis.

    Science.gov (United States)

    Farris, D J; Lichtwark, G A; Brown, N A T; Cresswell, A G

    2016-07-01

    Generating high leg power outputs is important for executing rapid movements. Squats are commonly used to increase leg strength and power. Therefore, it is useful to understand factors affecting power output in squatting. We aimed to deconstruct the mechanisms behind why power is maximized at certain resistances in squatting. Ten male rowers (age = 20 ± 2.2 years; height = 1.82 ± 0.03 m; mass = 86 ± 11 kg) performed maximal power squats with resistances ranging from body weight to 80% of their one repetition maximum (1RM). Three-dimensional kinematics was combined with ground reaction force (GRF) data in an inverse dynamics analysis to calculate leg joint moments and powers. System center of mass (COM) velocity and power were computed from GRF data. COM power was maximized across a range of resistances from 40% to 60% 1RM. This range was identified because a trade-off in hip and knee joint powers existed across this range, with maximal knee joint power occurring at 40% 1RM and maximal hip joint power at 60% 1RM. A non-linear system force-velocity relationship was observed that dictated large reductions in COM power below 20% 1RM and above 60% 1RM. These reductions were due to constraints on the control of the movement.

  16. Increases in perinatal mortality in prefectures contaminated by the Fukushima nuclear power plant accident in Japan

    Science.gov (United States)

    Scherb, Hagen Heinrich; Mori, Kuniyoshi; Hayashi, Keiji

    2016-01-01

    Abstract Descriptive observational studies showed upward jumps in secular European perinatal mortality trends after Chernobyl. The question arises whether the Fukushima nuclear power plant accident entailed similar phenomena in Japan. For 47 prefectures representing 15.2 million births from 2001 to 2014, the Japanese government provides monthly statistics on 69,171 cases of perinatal death of the fetus or the newborn after 22 weeks of pregnancy to 7 days after birth. Employing change-point methodology for detecting alterations in longitudinal data, we analyzed time trends in perinatal mortality in the Japanese prefectures stratified by exposure to estimate and test potential increases in perinatal death proportions after Fukushima possibly associated with the earthquake, the tsunami, or the estimated radiation exposure. Areas with moderate to high levels of radiation were compared with less exposed and unaffected areas, as were highly contaminated areas hit versus untroubled by the earthquake and the tsunami. Ten months after the earthquake and tsunami and the subsequent nuclear accident, perinatal mortality in 6 severely contaminated prefectures jumped up from January 2012 onward: jump odds ratio 1.156; 95% confidence interval (1.061, 1.259), P-value 0.0009. There were slight increases in areas with moderate levels of contamination and no increases in the rest of Japan. In severely contaminated areas, the increases of perinatal mortality 10 months after Fukushima were essentially independent of the numbers of dead and missing due to the earthquake and the tsunami. Perinatal mortality in areas contaminated with radioactive substances started to increase 10 months after the nuclear accident relative to the prevailing and stable secular downward trend. These results are consistent with findings in Europe after Chernobyl. Since observational studies as the one presented here may suggest but cannot prove causality because of unknown and uncontrolled factors or

  17. Multiple Sclerosis Increases Fracture Risk: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Guixian Dong

    2015-01-01

    Full Text Available Purpose. The association between multiple sclerosis (MS and fracture risk has been reported, but results of previous studies remain controversial and ambiguous. To assess the association between MS and fracture risk, a meta-analysis was performed. Method. Based on comprehensive searches of the PubMed, Embase, and Web of Science, we identified outcome data from all articles estimating the association between MS and fracture risk. The pooled risk ratios (RRs with 95% confidence intervals (CIs were calculated. Results. A significant association between MS and fracture risk was found. This result remained statistically significant when the adjusted RRs were combined. Subgroup analysis stratified by the site of fracture suggested significant associations between MS and tibia fracture risk, femur fracture risk, hip fracture risk, pelvis fracture risk, vertebrae fracture risk, and humerus fracture risk. In the subgroup analysis by gender, female MS patients had increased fracture risk. When stratified by history of drug use, use of antidepressants, hypnotics/anxiolytics, anticonvulsants, and glucocorticoids increased the risk of fracture risk in MS patients. Conclusions. This meta-analysis demonstrated that MS was significantly associated with fracture risk.

  18. Analysis of Trinity Power Metrics for Automated Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Michalenko, Ashley Christine [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-28

    This is a presentation from Los Alamos National Laboraotyr (LANL) about the analysis of trinity power metrics for automated monitoring. The following topics are covered: current monitoring efforts, motivation for analysis, tools used, the methodology, work performed during the summer, and future work planned.

  19. Power Grid Data Analysis with R and Hadoop

    Energy Technology Data Exchange (ETDEWEB)

    Hafen, Ryan P.; Gibson, Tara D.; Kleese van Dam, Kerstin; Critchlow, Terence J.

    2014-01-01

    This book chapter presents an approach to analysis of large-scale time-series sensor information based on our experience with power grid data. We use the R-Hadoop Integrated Programming Environment (RHIPE) to analyze a 2TB data set and present code and results for this analysis.

  20. AC Versus DC Link Comparison Based on Power Flow Analysis of a Multimachine Power System

    OpenAIRE

    Mohammed Abdeljalil DJEHAF; Sid Ahmed ZIDI; Youcef DJILANI KOBIBI

    2014-01-01

    Deregulation and privatization is posing new challenges on high voltage transmission and on distributions systems as well. An increasingly liberalized market will encourage trading opportunities to be identified and developed. High voltage power electronics, such as HVDC (High Voltage Direct Current) and FACTS (Flexible AC Transmission Systems) provide the necessary features to avoid technical problems in heavily loaded power systems; HVDC offers most advantages: it can be used for system int...

  1. k-Nearest Neighbors Algorithm in Profiling Power Analysis Attacks

    Directory of Open Access Journals (Sweden)

    Z. Martinasek

    2016-06-01

    Full Text Available Power analysis presents the typical example of successful attacks against trusted cryptographic devices such as RFID (Radio-Frequency IDentifications and contact smart cards. In recent years, the cryptographic community has explored new approaches in power analysis based on machine learning models such as Support Vector Machine (SVM, RF (Random Forest and Multi-Layer Perceptron (MLP. In this paper, we made an extensive comparison of machine learning algorithms in the power analysis. For this purpose, we implemented a verification program that always chooses the optimal settings of individual machine learning models in order to obtain the best classification accuracy. In our research, we used three datasets, the first containing the power traces of an unprotected AES (Advanced Encryption Standard implementation. The second and third datasets are created independently from public available power traces corresponding to a masked AES implementation (DPA Contest v4. The obtained results revealed some interesting facts, namely, an elementary k-NN (k-Nearest Neighbors algorithm, which has not been commonly used in power analysis yet, shows great application potential in practice.

  2. Design and Analysis of Sequential Elements for Low Power Clocking System with Low Power Techniques

    Directory of Open Access Journals (Sweden)

    S.Sasidhar Reddy

    2014-09-01

    Full Text Available This paper proposed the design of sequential elements for low power clocking system with low low power techniques for saving the power. Power consumption is a major bottleneck of system performance and is listed as one of the top three challenges in International Technology Roadmap for Semiconductor 2008. In practice, a large portion of the on chip power is consumed by the clock system which is made of the clock distribution network and flop-flops. In this paper, various design techniques for a low power clocking system are surveyed. Among them is an effective way to reduce capacity of the clock load by minimizing number of clocked transistors. To approach this, proposed a novel clocked pair shared flip-flop which reduces the number of local clocked transistors by approximately 40%. A 24% reduction of clock driving power is achieved. In addition, low swing and double edge clocking, can be easily incorporated into the new flip-flop to build clocking systems. As the feature size becomes smaller, shorter channel lengths result in increased sub-threshold leakage current through a transistor when it is off. Dual sleep and sleepy stack methods are proposed to avoid static power consumption; the flip flops are simulated using HSPICE.

  3. The Photovoltaic Heat Island Effect: Larger solar power plants increase local temperatures

    Science.gov (United States)

    Barron-Gafford, Greg A.; Minor, Rebecca L.; Allen, Nathan A.; Cronin, Alex D.; Brooks, Adria E.; Pavao-Zuckerman, Mitchell A.

    2016-01-01

    While photovoltaic (PV) renewable energy production has surged, concerns remain about whether or not PV power plants induce a “heat island” (PVHI) effect, much like the increase in ambient temperatures relative to wildlands generates an Urban Heat Island effect in cities. Transitions to PV plants alter the way that incoming energy is reflected back to the atmosphere or absorbed, stored, and reradiated because PV plants change the albedo, vegetation, and structure of the terrain. Prior work on the PVHI has been mostly theoretical or based upon simulated models. Furthermore, past empirical work has been limited in scope to a single biome. Because there are still large uncertainties surrounding the potential for a PHVI effect, we examined the PVHI empirically with experiments that spanned three biomes. We found temperatures over a PV plant were regularly 3–4 °C warmer than wildlands at night, which is in direct contrast to other studies based on models that suggested that PV systems should decrease ambient temperatures. Deducing the underlying cause and scale of the PVHI effect and identifying mitigation strategies are key in supporting decision-making regarding PV development, particularly in semiarid landscapes, which are among the most likely for large-scale PV installations. PMID:27733772

  4. The Photovoltaic Heat Island Effect: Larger solar power plants increase local temperatures.

    Science.gov (United States)

    Barron-Gafford, Greg A; Minor, Rebecca L; Allen, Nathan A; Cronin, Alex D; Brooks, Adria E; Pavao-Zuckerman, Mitchell A

    2016-10-13

    While photovoltaic (PV) renewable energy production has surged, concerns remain about whether or not PV power plants induce a "heat island" (PVHI) effect, much like the increase in ambient temperatures relative to wildlands generates an Urban Heat Island effect in cities. Transitions to PV plants alter the way that incoming energy is reflected back to the atmosphere or absorbed, stored, and reradiated because PV plants change the albedo, vegetation, and structure of the terrain. Prior work on the PVHI has been mostly theoretical or based upon simulated models. Furthermore, past empirical work has been limited in scope to a single biome. Because there are still large uncertainties surrounding the potential for a PHVI effect, we examined the PVHI empirically with experiments that spanned three biomes. We found temperatures over a PV plant were regularly 3-4 °C warmer than wildlands at night, which is in direct contrast to other studies based on models that suggested that PV systems should decrease ambient temperatures. Deducing the underlying cause and scale of the PVHI effect and identifying mitigation strategies are key in supporting decision-making regarding PV development, particularly in semiarid landscapes, which are among the most likely for large-scale PV installations.

  5. The Photovoltaic Heat Island Effect: Larger solar power plants increase local temperatures

    Science.gov (United States)

    Barron-Gafford, Greg A.; Minor, Rebecca L.; Allen, Nathan A.; Cronin, Alex D.; Brooks, Adria E.; Pavao-Zuckerman, Mitchell A.

    2016-10-01

    While photovoltaic (PV) renewable energy production has surged, concerns remain about whether or not PV power plants induce a “heat island” (PVHI) effect, much like the increase in ambient temperatures relative to wildlands generates an Urban Heat Island effect in cities. Transitions to PV plants alter the way that incoming energy is reflected back to the atmosphere or absorbed, stored, and reradiated because PV plants change the albedo, vegetation, and structure of the terrain. Prior work on the PVHI has been mostly theoretical or based upon simulated models. Furthermore, past empirical work has been limited in scope to a single biome. Because there are still large uncertainties surrounding the potential for a PHVI effect, we examined the PVHI empirically with experiments that spanned three biomes. We found temperatures over a PV plant were regularly 3–4 °C warmer than wildlands at night, which is in direct contrast to other studies based on models that suggested that PV systems should decrease ambient temperatures. Deducing the underlying cause and scale of the PVHI effect and identifying mitigation strategies are key in supporting decision-making regarding PV development, particularly in semiarid landscapes, which are among the most likely for large-scale PV installations.

  6. New Solutions For Increasing Environmental Protection During Severe Accidents At Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kulyukhin, Sergei A.; Mikheev, Nikolai B. [Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow (Russian Federation); Falkovskii, Leo N.; Reshetov, Leo A.; Zvetkova, Marianna Ya. [All-Russian Research Institute of Atomic Machine-Building, Moscow, Russia (Russian Federation); Yagodkin, Ivan V.; Osipov, Viktor P.; Skvortsov, Sergei S. [Institute of Physics and Power Engineering, Obninsk (Russian Federation); Berkovich, Viktor M.; Taranov, Gennadii S.; Grigor' ev, Mikhail M. [Institute ' Atomenergoproekt' , Moscow (Russian Federation); Meshkov, Vladimir M.; Noskov, Andrei A.; Mitrofanov, Mikhail I. [ROSENERGOATOM Concern, Moscow (Russian Federation)

    2008-07-01

    This paper reports new solutions for increasing environmental protection during severe accidents at NPPs. For NPPs with two protective shells and pressure release system such as WWER-1000 we suggest a new comprehensive, passive-mode environmental protection system of decontamination of the radioactive air-steam mixture from the containment and the inter-containment area, which includes the 'wet' stage (scrubbers, etc.), the 'dry' stage (sorption module), and also an ejector, which in a passive mode is capable of solving the multi-purpose task of decontamination of the air-steam mixture. For Russian WWER-440/230 NPPs we suggest three protection levels: 1) a jet-vortex condenser; 2) the spray system; 3) a sorption module. For modern designs of new generation NPPs, which do not provide for pressure release systems, we proposed a new passive filtering system together with the passive heat-removal system, which can be used during severe accidents in case all power supply units become unavailable. (authors)

  7. Increased demands for modern power plants. Gas and coal-fired power plants; Gestiegene Anforderungen an moderne Kraftwerke. Gas- und Kohlekraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Brautsch, Andreas [Alstom Power, Baden (Switzerland). CCS; Goll, Bringfried; Hestermann, Rolf [Alstom Power Systems GmbH, Mannheim (Germany); Peter, Torsten; Timmermann, Leif [Alstom Power Systems GmbH, Stuttgart (Germany); Rieck, Markus

    2011-07-01

    Driven by the mega trends of climate protection, increase in efficiency and flexibility, the demands for low CO{sub 2} and low emission technology, low specific fuel consumption and maximum control capability has increased significantly. Due to the energy strategy submitted by the Federal government, the demands on modern power plants are still further emphasized.

  8. The Murchison Widefield Array 21 cm Power Spectrum Analysis Methodology

    CERN Document Server

    Jacobs, Daniel C; Trott, C M; Dillon, Joshua S; Pindor, B; Sullivan, I S; Pober, J C; Barry, N; Beardsley, A P; Bernardi, G; Bowman, Judd D; Briggs, F; Cappallo, R J; Carroll, P; Corey, B E; de Oliveira-Costa, A; Emrich, D; Ewall-Wice, A; Feng, L; Gaensler, B M; Goeke, R; Greenhill, L J; Hewitt, J N; Hurley-Walker, N; Johnston-Hollitt, M; Kaplan, D L; Kasper, J C; Kim, H S; Kratzenberg, E; Lenc, E; Line, J; Loeb, A; Lonsdale, C J; Lynch, M J; McKinley, B; McWhirter, S R; Mitchell, D A; Morales, M F; Morgan, E; Neben, A R; Thyagarajan, N; Oberoi, D; Offringa, A R; Ord, S M; Paul, S; Prabu, T; Procopio, P; Riding, J; Rogers, A E E; Roshi, A; Shankar, N Udaya; Sethi, Shiv K; Srivani, K S; Subrahmanyan, R; Tegmark, M; Tingay, S J; Waterson, M; Wayth, R B; Webster, R L; Whitney, A R; Williams, A; Williams, C L; Wu, C; Wyithe, J S B

    2016-01-01

    We present the 21 cm power spectrum analysis approach of the Murchison Widefield Array Epoch of Reionization project. In this paper, we compare the outputs of multiple pipelines for the purpose of validating statistical limits cosmological hydrogen at redshifts between 6 and 12. Multiple, independent, data calibration and reduction pipelines are used to make power spectrum limits on a fiducial night of data. Comparing the outputs of imaging and power spectrum stages highlights differences in calibration, foreground subtraction and power spectrum calculation. The power spectra found using these different methods span a space defined by the various tradeoffs between speed, accuracy, and systematic control. Lessons learned from comparing the pipelines range from the algorithmic to the prosaically mundane; all demonstrate the many pitfalls of neglecting reproducibility. We briefly discuss the way these different methods attempt to handle the question of evaluating a significant detection in the presence of foregr...

  9. The Murchison Widefield Array 21 cm Power Spectrum Analysis Methodology

    Science.gov (United States)

    Jacobs, Daniel C.; Hazelton, B. J.; Trott, C. M.; Dillon, Joshua S.; Pindor, B.; Sullivan, I. S.; Pober, J. C.; Barry, N.; Beardsley, A. P.; Bernardi, G.; Bowman, Judd D.; Briggs, F.; Cappallo, R. J.; Carroll, P.; Corey, B. E.; de Oliveira-Costa, A.; Emrich, D.; Ewall-Wice, A.; Feng, L.; Gaensler, B. M.; Goeke, R.; Greenhill, L. J.; Hewitt, J. N.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kaplan, D. L.; Kasper, J. C.; Kim, HS; Kratzenberg, E.; Lenc, E.; Line, J.; Loeb, A.; Lonsdale, C. J.; Lynch, M. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Neben, A. R.; Thyagarajan, N.; Oberoi, D.; Offringa, A. R.; Ord, S. M.; Paul, S.; Prabu, T.; Procopio, P.; Riding, J.; Rogers, A. E. E.; Roshi, A.; Udaya Shankar, N.; Sethi, Shiv K.; Srivani, K. S.; Subrahmanyan, R.; Tegmark, M.; Tingay, S. J.; Waterson, M.; Wayth, R. B.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C. L.; Wu, C.; Wyithe, J. S. B.

    2016-07-01

    We present the 21 cm power spectrum analysis approach of the Murchison Widefield Array Epoch of Reionization project. In this paper, we compare the outputs of multiple pipelines for the purpose of validating statistical limits cosmological hydrogen at redshifts between 6 and 12. Multiple independent data calibration and reduction pipelines are used to make power spectrum limits on a fiducial night of data. Comparing the outputs of imaging and power spectrum stages highlights differences in calibration, foreground subtraction, and power spectrum calculation. The power spectra found using these different methods span a space defined by the various tradeoffs between speed, accuracy, and systematic control. Lessons learned from comparing the pipelines range from the algorithmic to the prosaically mundane; all demonstrate the many pitfalls of neglecting reproducibility. We briefly discuss the way these different methods attempt to handle the question of evaluating a significant detection in the presence of foregrounds.

  10. Analysis of Power Model for Linear Plasma Device

    Science.gov (United States)

    Zhang, Weiwei; Deng, Baiquan; Zuo, Haoyi; Zheng, Xianjun; Cao, Xiaogang; Xue, Xiaoyan; Ou, Wei; Cao, Zhi; Gou, Fujun

    2016-08-01

    A single cathode linear plasma device has been designed and constructed to investigate the interactions between plasma and materials at the Sichuan University. In order to further investigate the Ohmic power of the device, the output heat load on the specimen and electric potential difference (between cathode and anode) have been tested under different discharge currents. This special power distribution in the radial direction of the plasma discharge channel has also been discussed and described by some improved integral equations in this paper; it can be further simplified as P ∝ α-2 in one-parameter. Besides, we have measured the power loss of the channel under different discharge currents by the calorimetric method, calculated the effective power of the device and evaluated the performances of the plasma device through the power efficiency analysis. supported by International Thermonuclear Experimental Reactor (ITER) Program (No. 2013GB114003) and National Natural Science Foundation of China (Nos. 11275135 and 11475122)

  11. Statistical analysis of cascading failures in power grids

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, Michael [Los Alamos National Laboratory; Pfitzner, Rene [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory

    2010-12-01

    We introduce a new microscopic model of cascading failures in transmission power grids. This model accounts for automatic response of the grid to load fluctuations that take place on the scale of minutes, when optimum power flow adjustments and load shedding controls are unavailable. We describe extreme events, caused by load fluctuations, which cause cascading failures of loads, generators and lines. Our model is quasi-static in the causal, discrete time and sequential resolution of individual failures. The model, in its simplest realization based on the Directed Current description of the power flow problem, is tested on three standard IEEE systems consisting of 30, 39 and 118 buses. Our statistical analysis suggests a straightforward classification of cascading and islanding phases in terms of the ratios between average number of removed loads, generators and links. The analysis also demonstrates sensitivity to variations in line capacities. Future research challenges in modeling and control of cascading outages over real-world power networks are discussed.

  12. Thermodynamic Analysis of Combined Cycle Power Plant

    Directory of Open Access Journals (Sweden)

    A.K.Tiwari,

    2010-04-01

    Full Text Available Air Bottoming Cycle (ABC can replace the heat recovery steam generator and the steam turbine of the conventionalcombined cycle plant. The exhaust energy of the topping gas turbine of existing combine cycle is sent to gas-air heat exchange, which heats the air in the secondary gas turbine cycle. In 1980’s the ABC was proposed as an alternative for the conventional steam bottoming cycle. In spite of the cost of reducing hardware installations it could achieve a thermal efficiency of 80%. The complete thermodynamic analysis of the system has been performed by using specially designed programme, enabling the variation of main independent variables. The result shows the gain in net work output as well as efficiency of combined cycle is 35% to 68%.

  13. Economic costs of managing of an electricity grid with increasing wind power penetration

    NARCIS (Netherlands)

    Prescott, R.; Kooten, van G.C.

    2009-01-01

    We examine the impact of policy choices, including a carbon tax, on the optimal allocation of power across different generation sources and on future investments in generating facilities. The main focus is on the Alberta power grid, as it is heavily dependent on fossil fuels and has only limited tie

  14. Increasing of Manoeuvrability of Cogeneration Combined Cycle Power Plants Owing to the Usage of Electric Boilers

    Directory of Open Access Journals (Sweden)

    S. Kachan

    2013-01-01

    Full Text Available The paper contains the results of efficiency evaluation  of using the electric boilers to improve maneuver capabilities of the cogeneration combined cycle power plants (as an example, 230 MW combined cycle unit of Minsk CHP-3 in comparison with the traditional steam-turbine units of cogeneration power plants.

  15. Volkswagen vs. Porsche. A Power-Index Analysis.

    OpenAIRE

    Roland Kirstein

    2009-01-01

    After Porsche SE took over Volkswagen AG, its supervisory board consists of three groups: The Porsche shareholders hold 6 seats, while the 324,000 Volkswagen employees and the 12,000 Porsche employees will be represented by 3 delegates each. This paper perceives each of these three groups as unitary players and presents a power-index analysis of this supervisory board. It shows that, unless the Porsche employees are made completely powerless, Porsche and VW employees will have identical power...

  16. Electrical Power Distribution and Control Modeling and Analysis

    Science.gov (United States)

    Fu, Johnny S.; Liffring, Mark; Mehdi, Ishaque S.

    2001-01-01

    This slide presentation reviews the use of Electrical Power Distribution and Control (EPD&C) Modeling and how modeling can support analysis. The presentation discusses using the EASY5 model to simulate and analyze the Space Shuttle Electric Auxiliary Power Unit. Diagrams of the model schematics are included, as well as graphs of the battery cell impedance, hydraulic load dynamics, and EPD&C response to hydraulic load variations.

  17. Power Budget Analysis for Waveguide-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    Wang, Zilong; Pearce, Stuart J; Lin, Yung-Chun; Zervas, Michalis N; Bartlett, Philip N; Wilkinson, James S

    2016-08-01

    Waveguide-enhanced Raman spectroscopy (WERS) is emerging as an attractive alternative to plasmonic surface-enhanced Raman spectroscopy approaches as it can provide more reproducible quantitative spectra on a robust chip without the need for nanostructured plasmonic materials. Realizing portable WERS systems with high sensitivity using low-cost laser diodes and compact spectrometers requires a detailed analysis of the power budget from laser to spectrometer chip. In this paper, we describe theoretical optimization of planar waveguides for maximum Raman excitation efficiency, demonstrate WERS for toluene on a silicon process compatible high index contrast tantalum pentoxide waveguide, measure the absolute conversion efficiency from pump power to received power in an individual Raman line, and compare this with a power budget analysis of the complete system including collection with an optical fiber and interfacing to a compact spectrometer. Optimized 110 nm thick Ta2O5 waveguides on silica substrates excited at a wavelength of 637 nm are shown experimentally to yield overall system power conversion efficiency of ∼0.5 × 10(-12) from the pump power in the waveguide to the collected Raman power in the 1002 cm(-1) Raman line of toluene, in comparison with a calculated efficiency of 3.9 × 10(-12) Collection efficiency is dictated by the numerical and physical apertures of the spectral detection system but may be improved by further engineering the spatial and angular Raman scattering distributions.

  18. The monotonic increasing relationship between average powers of CMOS VLSI circuits with and without delay and its applications

    Institute of Scientific and Technical Information of China (English)

    骆祖莹; 闵应骅; 杨士元; 李晓维

    2002-01-01

    The authors theoretically describe the monotonic increasing relationship between averagepowers of a CMOS VLSI circuit with and without delay. The power of an ideal circuit without delay, whichcan be fast computed, has been used as the evaluation criterion for the power of a practical circuit withdelay, which needs more computing time, in such fields as fast estimation for the average power and themaximum power, and fast optimization for the Iow test power. The authors propose a novel simulationapproach that uses delay-free power to compact a long input vector pair sequence into a short sequenceand then, uses the compacted one to fast simulate the average (or maximum) power for a CMOS circuit. Incomparison with the traditional simulation approach that uses an un-compacted input sequence to simu-late the average (or maximum) power, experiment results demonstrate that in the field of fast estimationfor the average power, the present approach can be 6-10 times faster without significant loss in accuracy(less than 3.5% on average), and in the field of fast estimation for the maximum power, this approach canbe 6-8 times faster without significant loss in accuracy (less than 5% on average). In the field of fast op-timization for the test power, the authors propose a novel delay-free power optimization approach for thetest power. Experiment results demonstrate that, in comparison with the approach of direct optimizationand the approach of Hamming distance optimization, this approach is of the highest optimization effi-ciency because it needs shorter time (16.84%) to obtain a better optimization effect (reducing 35.11% testpower).

  19. Thermodynamic, energy efficiency, and power density analysis of reverse electrodialysis power generation with natural salinity gradients.

    Science.gov (United States)

    Yip, Ngai Yin; Vermaas, David A; Nijmeijer, Kitty; Elimelech, Menachem

    2014-05-06

    Reverse electrodialysis (RED) can harness the Gibbs free energy of mixing when fresh river water flows into the sea for sustainable power generation. In this study, we carry out a thermodynamic and energy efficiency analysis of RED power generation, and assess the membrane power density. First, we present a reversible thermodynamic model for RED and verify that the theoretical maximum extractable work in a reversible RED process is identical to the Gibbs free energy of mixing. Work extraction in an irreversible process with maximized power density using a constant-resistance load is then examined to assess the energy conversion efficiency and power density. With equal volumes of seawater and river water, energy conversion efficiency of ∼ 33-44% can be obtained in RED, while the rest is lost through dissipation in the internal resistance of the ion-exchange membrane stack. We show that imperfections in the selectivity of typical ion exchange membranes (namely, co-ion transport, osmosis, and electro-osmosis) can detrimentally lower efficiency by up to 26%, with co-ion leakage being the dominant effect. Further inspection of the power density profile during RED revealed inherent ineffectiveness toward the end of the process. By judicious early discontinuation of the controlled mixing process, the overall power density performance can be considerably enhanced by up to 7-fold, without significant compromise to the energy efficiency. Additionally, membrane resistance was found to be an important factor in determining the power densities attainable. Lastly, the performance of an RED stack was examined for different membrane conductivities and intermembrane distances simulating high performance membranes and stack design. By thoughtful selection of the operating parameters, an efficiency of ∼ 37% and an overall gross power density of 3.5 W/m(2) represent the maximum performance that can potentially be achieved in a seawater-river water RED system with low

  20. Statistical Analysis of the Impact of Wind Power on Market Quantities and Power Flows

    DEFF Research Database (Denmark)

    Pinson, Pierre; Jónsson, Tryggvi; Zugno, Marco

    2012-01-01

    in Europe. Due to the dimensionality and nonlinearity of these effects, the necessary concepts of dimension reduction using Principal Component Analysis (PCA), as well as nonlinear regression are described. Example application results are given for European cross-border flows, as well as for the impact...... of load and wind power forecasts on Danish and German electricity markets....

  1. Methods and tools for analysis and optimization of power plants

    Energy Technology Data Exchange (ETDEWEB)

    Assadi, Mohsen

    2000-09-01

    The most noticeable advantage of the introduction of the computer-aided tools in the field of power generation, has been the ability to study the plant's performance prior to the construction phase. The results of these studies have made it possible to change and adjust the plant layout to match the pre-defined requirements. Further development of computers in recent years has opened up for implementation of new features in the existing tools and also for the development of new tools for specific applications, like thermodynamic and economic optimization, prediction of the remaining component life time, and fault diagnostics, resulting in improvement of the plant's performance, availability and reliability. The most common tools for pre-design studies are heat and mass balance programs. Further thermodynamic and economic optimization of plant layouts, generated by the heat and mass balance programs, can be accomplished by using pinch programs, exergy analysis and thermoeconomics. Surveillance and fault diagnostics of existing systems can be performed by using tools like condition monitoring systems and artificial neural networks. The increased number of tools and their various construction and application areas make the choice of the most adequate tool for a certain application difficult. In this thesis the development of different categories of tools and techniques, and their application area are reviewed and presented. Case studies on both existing and theoretical power plant layouts have been performed using different commercially available tools to illuminate their advantages and shortcomings. The development of power plant technology and the requirements for new tools and measurement systems have been briefly reviewed. This thesis contains also programming techniques and calculation methods concerning part-load calculations using local linearization, which has been implemented in an inhouse heat and mass balance program developed by the author

  2. Operational Modal Analysis of Wind Turbine Speed-increase Gearbox

    Directory of Open Access Journals (Sweden)

    LI Yafeng

    2013-11-01

    Full Text Available Speed increase transmission gear box is the primary vibration and noise source of wind turbine, Operational modal method was adopted to collect impact data and response data of each point based on the gearbox test model. ANSYS finite element model is established to simulate the wind turbine gearbox. Then the modal frequencies of the two methods were compared to ensure the test model is correct. The results show that operational modal method can be applied in wind turbine gearbox modal analysis and it has important guiding significance to gearbox fault diagnosis and reliability and maintainability improving.  

  3. Fretting corrosion in power contacts: Electrical and thermal analysis

    OpenAIRE

    El Mossouess, S; Benjemâa, N; Carvou, E; El Abdi, R; Benmamas, L; Doublet, L

    2014-01-01

    International audience; -Fretting corrosion phenomenon is known as the main cause of contact resistance increasing in signal contact. But for power connectors this undesirable phenomenon in embarked systems is more complex because high current induces high voltages and subsequent Joule overheating can be expected during vibration. Our study deals with contact similar of power connectors ones submitted to vibration am-plitudes up to 25 micrometres at frequencies of a few 10Hz under a current r...

  4. Fiber optic sensor solutions for increase of efficiency and availability of electric power generators

    Science.gov (United States)

    Willsch, M.; Bosselmann, T.; Villnow, M.

    2010-09-01

    Multiple fiber optic sensors have been developed for strain, vibration, temperature, magnetic field and air flow measurement in electric power generators. This paper describes the recent state of development and reports about todays field experience.

  5. Increasing the resilience and security of the United States' power infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Happenny, Sean F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-08-01

    The United States' power infrastructure is aging, underfunded, and vulnerable to cyber attack. Emerging smart grid technologies may take some of the burden off of existing systems and make the grid as a whole more efficient, reliable, and secure. The Pacific Northwest National Laboratory (PNNL) is funding research into several aspects of smart grid technology and grid security, creating a software simulation tool that will allow researchers to test power infrastructure control and distribution paradigms by utilizing different smart grid technologies to determine how the grid and these technologies react under different circumstances. Understanding how these systems behave in real-world conditions will lead to new ways to make our power infrastructure more resilient and secure. Demonstrating security in embedded systems is another research area PNNL is tackling. Many of the systems controlling the U.S. critical infrastructure, such as the power grid, lack integrated security and the aging networks protecting them are becoming easier to attack.

  6. Implementation of Line Stability Index for Contingency Analysis and Screening in Power Systems

    Directory of Open Access Journals (Sweden)

    Vivek Kumar

    2012-01-01

    Full Text Available Problem statement: Estimating the margin in the loadability of the power system is essential in the real time voltage stability assessment. Voltage stability is currently one of the most important research areas in the field of electrical power system. In power system operation unpredictable events is termed as contingency and may be caused by line outage in the system which could lead to entire system instability. Voltage stability analysis and contingency analysis are would be performed in a power system by evaluating the derived voltage stability index. Approach: Voltage Stability Index Lmn can be useful for estimating the distance from the current operating point to voltage collapse point. The index can either reveal the critical bus of a power system or the stability of each line connected between two buses in an interconnected network or evaluate the voltage stability margins of a system. Results: Flexible Alternating Current Transmission Systems (FACTS devices have been proposed as an effective solution for controlling power flow and regulating bus voltage in electrical power systems, resulting in an increased transfer capability, low system losses and improved stability. However to what extent the performance of FACTS devices can be brought out highly depends upon the location and the parameters of these devices. Unified Power Flow Controller (UPFC is the most promising FACTS device for power flow control. Conclusion/Recommendations: The performance of this index is presented and the effectiveness of the analyzed methods is demonstrated through simulation studies in IEEE 14 bus reliability test systems.

  7. Increase of Power Rates Has a Big Impact on Aluminum Plants

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> An important cause for the recent adjustment ofpower rates in China is to contain the growth ofhigh-energy-consumption industries by impos-ing differentiated power rates.Therefore,as thefirst of six high-energy-consumption industries,the primary aluminum industry has receivedspecial attention.Based on the complicatedplan on adjustment of power rates currentlyavailable,it is expected that approximately800,000 tons of self-baking pot production ca-

  8. Dynamics of global supply chain and electric power networks: Models, pricing analysis, and computations

    Science.gov (United States)

    Matsypura, Dmytro

    In this dissertation, I develop a new theoretical framework for the modeling, pricing analysis, and computation of solutions to electric power supply chains with power generators, suppliers, transmission service providers, and the inclusion of consumer demands. In particular, I advocate the application of finite-dimensional variational inequality theory, projected dynamical systems theory, game theory, network theory, and other tools that have been recently proposed for the modeling and analysis of supply chain networks (cf. Nagurney (2006)) to electric power markets. This dissertation contributes to the extant literature on the modeling, analysis, and solution of supply chain networks, including global supply chains, in general, and electric power supply chains, in particular, in the following ways. It develops a theoretical framework for modeling, pricing analysis, and computation of electric power flows/transactions in electric power systems using the rationale for supply chain analysis. The models developed include both static and dynamic ones. The dissertation also adds a new dimension to the methodology of the theory of projected dynamical systems by proving that, irrespective of the speeds of adjustment, the equilibrium of the system remains the same. Finally, I include alternative fuel suppliers, along with their behavior into the supply chain modeling and analysis framework. This dissertation has strong practical implications. In an era in which technology and globalization, coupled with increasing risk and uncertainty, complicate electricity demand and supply within and between nations, the successful management of electric power systems and pricing become increasingly pressing topics with relevance not only for economic prosperity but also national security. This dissertation addresses such related topics by providing models, pricing tools, and algorithms for decentralized electric power supply chains. This dissertation is based heavily on the following

  9. A wirelessly-powered homecage with animal behavior analysis and closed-loop power control.

    Science.gov (United States)

    Yaoyao Jia; Zheyuan Wang; Canales, Daniel; Tinkler, Morgan; Chia-Chun Hsu; Madsen, Teresa E; Mirbozorgi, S Abdollah; Rainnie, Donald; Ghovanloo, Maysam

    2016-08-01

    This paper presents a new EnerCage-homecage system, EnerCage-HC2, for longitudinal electrophysiology data acquisition experiments on small freely moving animal subjects, such as rodents. EnerCage-HC2 is equipped with multi-coil wireless power transmission (WPT), closed-loop power control, bidirectional data communication via Bluetooth Low Energy (BLE), and Microsoft Kinect® based animal behavior tracking and analysis. The EnerCage-HC2 achieves a homogeneous power transfer efficiency (PTE) of 14% on average, with ~42 mW power delivered to the load (PDL) at a nominal height of 7 cm by the closed-loop power control mechanism. The Microsoft Kinect® behavioral analysis algorithm can not only track the animal position in real-time but also classify 5 different types of rodent behaviors: standstill, walking, grooming, rearing, and rotating. A proof-of-concept in vivo experiment was conducted on two awake freely behaving rats while successfully operating a one-channel stimulator and generating an ethogram.

  10. Locality-Driven Parallel Static Analysis for Power Delivery Networks

    KAUST Repository

    Zeng, Zhiyu

    2011-06-01

    Large VLSI on-chip Power Delivery Networks (PDNs) are challenging to analyze due to the sheer network complexity. In this article, a novel parallel partitioning-based PDN analysis approach is presented. We use the boundary circuit responses of each partition to divide the full grid simulation problem into a set of independent subgrid simulation problems. Instead of solving exact boundary circuit responses, a more efficient scheme is proposed to provide near-exact approximation to the boundary circuit responses by exploiting the spatial locality of the flip-chip-type power grids. This scheme is also used in a block-based iterative error reduction process to achieve fast convergence. Detailed computational cost analysis and performance modeling is carried out to determine the optimal (or near-optimal) number of partitions for parallel implementation. Through the analysis of several large power grids, the proposed approach is shown to have excellent parallel efficiency, fast convergence, and favorable scalability. Our approach can solve a 16-million-node power grid in 18 seconds on an IBM p5-575 processing node with 16 Power5+ processors, which is 18.8X faster than a state-of-the-art direct solver. © 2011 ACM.

  11. Financial risk analysis and prediction of Chinese power industry

    Energy Technology Data Exchange (ETDEWEB)

    Jin, H.; An, C. [Hebei Univ. of Technology, Tianjin (China). School of Management; Zhang, C. [Nankai Univ., Tianjin (China). School of Business

    2009-03-11

    A study of 57 Shanghai and Shenzhen power industry companies was presented. The study considered financial ratios between companies in order to determine risk factors for financial crises. Financial data from the Shanghai and Shenzhen stock markets were used to investigate power company performance from 2006 to 2008. Data from the China Center for Economic Research (CCER) were also used. Results of the study indicated that the cash-to-current debt ratio, the return on equity (ROE), net asset growth ratio, and inventory turnover presented uncorrelated and significantly varying ratios for failed power companies. The study also showed that most power companies have a high proportion of liabilities, higher debt risk, low asset turnover ratios, and negative net working capital. Results of the analysis were used to design an early warning model that used logistic regression techniques to predict risk. 7 refs., 5 tabs.

  12. Increase of Power System Survivability with the Decision Support Tool CRIPS Based on Network Planning and Simulation Program PSS®SINCAL

    Science.gov (United States)

    Schwaegerl, Christine; Seifert, Olaf; Buschmann, Robert; Dellwing, Hermann; Geretshuber, Stefan; Leick, Claus

    The increased interconnection and automation of critical infrastructures enlarges the complexity of the dependency structures and - as consequence - the danger of cascading effects, e.g. causing area-wide blackouts in power supply networks that are currently after deregulation operated closer to their limits. New tools or an intelligent combination of existing approaches are required to increase the survivability of critical infrastructures. Within the IRRIIS project the expert system CRIPS was developed based on network simulations realised with PSS®SINCAL, an established tool to support the analysis and planning of electrical power, gas, water or heat networks. CRIPS assesses the current situation in power supply networks analysing the simulation results of the physical network behaviour and recommends corresponding decisions.

  13. Involvement of glutamatergic and GABAergic transmission in MK-801-increased gamma band oscillation power in rat cortical electroencephalograms.

    Science.gov (United States)

    Hiyoshi, T; Kambe, D; Karasawa, J; Chaki, S

    2014-11-07

    Hypofunction of the N-methyl-D-aspartic acid receptor (NMDAr) has been considered to play a crucial role in the pathophysiology of schizophrenia. In rodent electroencephalogram (EEG) studies, non-competitive NMDAr antagonists have been reported to produce aberrant basal gamma band oscillation (GBO), as observed in schizophrenia. Aberrations in GBO power have attracted attention as a translational biomarker for the development of novel antipsychotic drugs. However, the neuronal mechanisms as well as the pharmacological significance of NMDAr antagonist-induced aberrant GBO power have not been fully investigated. In the present study, to address the above questions, we examined the pharmacological properties of MK-801 (0.1 mg/kg)-increased basal GBO power in rat cortical EEG. Riluzole (3-10 mg/kg), a glutamate release inhibitor, reduced the MK-801-increased basal GBO power. In contrast, L-838,417 (1-3 mg/kg), an α2/3/5 subunit-selective GABAA receptor-positive allosteric modulator, enhanced the GBO increase. Antipsychotics such as haloperidol (0.05-0.3 mg/kg) and clozapine (1-10 mg/kg) dose-dependently attenuated the MK-801-increased GBO power. Likewise, LY379268 (0.3-3 mg/kg), an metabotropic glutamate 2/3 receptor (mGlu2/3 receptor) agonist, reduced the GBO increase in a dose-dependent manner, which was antagonized by an mGlu2/3 receptor antagonist LY341495. These results suggest that an increase in cortical GBO power induced by NMDAr hypofunction can be attributed to the aberrant activities of both excitatory pyramidal neurons and inhibitory interneurons in local circuits. The aberrant cortical GBO power reflecting cortical network dysfunction observed in schizophrenia might be a useful biomarker for the discovery of novel antipsychotic drugs.

  14. Incorporation of a Wind Generator Model into a Dynamic Power Flow Analysis

    Directory of Open Access Journals (Sweden)

    Angeles-Camacho C.

    2011-07-01

    Full Text Available Wind energy is nowadays one of the most cost-effective and practical options for electric generation from renewable resources. However, increased penetration of wind generation causes the power networks to be more depend on, and vulnerable to, the varying wind speed. Modeling is a tool which can provide valuable information about the interaction between wind farms and the power network to which they are connected. This paper develops a realistic characterization of a wind generator. The wind generator model is incorporated into an algorithm to investigate its contribution to the stability of the power network in the time domain. The tool obtained is termed dynamic power flow. The wind generator model takes on account the wind speed and the reactive power consumption by induction generators. Dynamic power flow analysis is carried-out using real wind data at 10-minute time intervals collected for one meteorological station. The generation injected at one point into the network provides active power locally and is found to reduce global power losses. However, the power supplied is time-varying and causes fluctuations in voltage magnitude and power fl ows in transmission lines.

  15. Remote Borehole Strainmeter Sites: Power system optimization improves data quality and increases equipment uptime

    Science.gov (United States)

    Pyatt, C.; Van Boskirk, E.; Gallaher, W.; Hodgkinson, K. M.; Henderson, D. B.; Gottlieb, M. H.; Johnson, W.; Fox, O.; Mencin, D.; Mattioli, G.

    2012-12-01

    The Earthscope Plate Boundary Observatory (PBO) Borehole strainmeter network consists of 74 sites, spanning the west coast of North America from Anza, California to Vancouver Island, British Columbia. Several instruments are installed at each site (including Gladwin Tensor Strainmeter, 3-component geophone, barometer, and rain gauge), with associated data storage and communications equipment. Selected sites also are co-located with high-precision GPS, tiltmeter, pore pressure sensor and metpack. The peak load for a site with VSAT communications is approximately 65W. Most sites are AC powered with battery backup systems. 21 sites are located in remote areas where AC power is unavailable; of these, 18 use solar panels and batteries as the primary power source. During O&M phase of PBO, two issues have brought the borehole solar sites into focus. First, most solar sites cannot continuously operate throughout the winter months because of inclement weather and local topography that blocks the solar array, which results in data loss. Second, high frequency noise is introduced into the instrument data stream by the solar charging system. Reducing noise levels at higher frequencies would decrease the detection threshold for short term transients, such as aseismic creep events, thus allowing researchers to leverage the overlap between simultaneous seismometer and strainmeter observations. Several improvements have been made to optimize the power system as well as decrease noise. TriStar TS-MPPT-60 solar controllers have been installed, which optimize solar flux by tracking and responding to the solar array maximum power point. The battery charge algorithm is designed to provide gains of up to 15% efficiency during winter months. In addition, the new solar controllers have been engineered to limit noise, and also feature remote network interfaces and data logging capability. For those sites where topography impacts the function of the solar power system, methanol fuel cells

  16. Optimum fiber tapers for increasing the power in the blue-edge of a supercontinuum - group-acceleration matching

    DEFF Research Database (Denmark)

    Sørensen, Simon Toft; Judge, Alexander; Thomsen, Carsten L.;

    2011-01-01

    and blueshifts an increased fraction of the energy in its DW when the gradient is decreased. This is quantified by the group-acceleration mismatch between the soliton and DW at the entrance of the taper. These findings have direct implications for the achievable power in the blue edge of a supercontinuum...... generated in a tapered fiber and explain observations of a lack of power in the blue edge....

  17. Power and Sample Size Calculations for Contrast Analysis in ANCOVA.

    Science.gov (United States)

    Shieh, Gwowen

    2017-01-01

    Analysis of covariance (ANCOVA) is commonly used in behavioral and educational research to reduce the error variance and improve the power of analysis of variance by adjusting the covariate effects. For planning and evaluating randomized ANCOVA designs, a simple sample-size formula has been proposed to account for the variance deflation factor in the comparison of two treatment groups. The objective of this article is to highlight an overlooked and potential problem of the exiting approximation and to provide an alternative and exact solution of power and sample size assessments for testing treatment contrasts. Numerical investigations are conducted to reveal the relative performance of the two procedures as a reliable technique to accommodate the covariate features that make ANCOVA design particularly distinctive. The described approach has important advantages over the current method in general applicability, methodological justification, and overall accuracy. To enhance the practical usefulness, computer algorithms are presented to implement the recommended power calculations and sample-size determinations.

  18. Evolving S Boxes with Reduced Differential Power Analysis Susceptibiltiy

    Science.gov (United States)

    2016-12-02

    finding S-boxes with high nonlinearity and low transparency order, if they exist. Additionally, we show that the cycle crossover yields more efficient...multiobjec- tive evolutionary algorithm · cycle crossover · differential power analysis · cryptanalysis · trade-off · Pareto front 1 Introduction Block...necessarily reflect the views of the Department of the Navy. Proper S-box design requires careful analysis of conflicting features. First, the designer

  19. Analysis of DC Power Transmission Using High Tc Superconducting Cables

    Institute of Scientific and Technical Information of China (English)

    Jun-Lian Zhang; Jian-Xun Jin

    2008-01-01

    A conceptual superconducting DC cable model is designed and its magnetic fields distribution is analyzed with Ansoft/Maxwell soft. A DC Power transmission system is also studied by using the Matlab/Simulink. With the DC Line and AC Ground Fault, the system losses analysis is introduced.The analysis results mainly include the magnetic fields distribution of the HTS cable model with Ansoft/Maxwell, the system loss, the DC Line and AC Ground Fault with Matlab/Simulation.

  20. Network topology and resilience analysis of South Korean power grid

    Science.gov (United States)

    Kim, Dong Hwan; Eisenberg, Daniel A.; Chun, Yeong Han; Park, Jeryang

    2017-01-01

    In this work, we present topological and resilience analyses of the South Korean power grid (KPG) with a broad voltage level. While topological analysis of KPG only with high-voltage infrastructure shows an exponential degree distribution, providing another empirical evidence of power grid topology, the inclusion of low voltage components generates a distribution with a larger variance and a smaller average degree. This result suggests that the topology of a power grid may converge to a highly skewed degree distribution if more low-voltage data is considered. Moreover, when compared to ER random and BA scale-free networks, the KPG has a lower efficiency and a higher clustering coefficient, implying that highly clustered structure does not necessarily guarantee a functional efficiency of a network. Error and attack tolerance analysis, evaluated with efficiency, indicate that the KPG is more vulnerable to random or degree-based attacks than betweenness-based intentional attack. Cascading failure analysis with recovery mechanism demonstrates that resilience of the network depends on both tolerance capacity and recovery initiation time. Also, when the two factors are fixed, the KPG is most vulnerable among the three networks. Based on our analysis, we propose that the topology of power grids should be designed so the loads are homogeneously distributed, or functional hubs and their neighbors have high tolerance capacity to enhance resilience.

  1. Approaches and methods for econometric analysis of market power

    DEFF Research Database (Denmark)

    Perekhozhuk, Oleksandr; Glauben, Thomas; Grings, Michael

    2017-01-01

    This study discusses two widely used approaches in the New Empirical Industrial Organization (NEIO) literature and examines the strengths and weaknesses of the Production-Theoretic Approach (PTA) and the General Identification Method (GIM) for the econometric analysis of market power in agricultu...

  2. The Analysis of The Fault of Electrical Power Steering

    Directory of Open Access Journals (Sweden)

    Zhang Li Wen

    2016-01-01

    Full Text Available This paper analysis the common fault types of primary Electrical Power Steering system, meanwhile classify every fault. It provides the basis for further troubleshooting and maintenance. At the same time this paper propose a practical working principle of fault-tolerant, in order to make the EPS system more security and durability.

  3. Analysis and characterization of security regions in power systems

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Progress is repoted in a study performed to investigate the concept of security regions in the context of power system security analysis. The background and motivation for this research, the results of 2 years of work, and proposed future studies are discussed. (LCL)

  4. PRICE DISCRIMINATION AND MARKET POWER: A THEORETICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Olga Smirnova

    2015-07-01

    Full Text Available This paper analyzes the contemporary theoretical and empirical research in the field of impact assessment of market power and conclusions about the possibilities of the company to implement price discrimination in different market structures. The results of the analysis allow to evaluate current approaches to antitrust regulation of price discrimination.

  5. Time series analysis : Smoothed correlation integrals, autocovariances, and power spectra

    NARCIS (Netherlands)

    Takens, F; Dumortier, F; Broer, H; Mawhin, J; Vanderbauwhede, A; Lunel, SV

    2005-01-01

    In this paper we relate notions from linear time series analyses, like autocovariances and power spectra, with notions from nonlinear times series analysis, like (smoothed) correlation integrals and the corresponding dimensions and entropies. The complete proofs of the results announced in this pape

  6. Solar Dynamic Power System Stability Analysis and Control

    Science.gov (United States)

    Momoh, James A.; Wang, Yanchun

    1996-01-01

    The objective of this research is to conduct dynamic analysis, control design, and control performance test of solar power system. Solar power system consists of generation system and distribution network system. A bench mark system is used in this research, which includes a generator with excitation system and governor, an ac/dc converter, six DDCU's and forty-eight loads. A detailed model is used for modeling generator. Excitation system is represented by a third order model. DDCU is represented by a seventh order system. The load is modeled by the combination of constant power and constant impedance. Eigen-analysis and eigen-sensitivity analysis are used for system dynamic analysis. The effects of excitation system, governor, ac/dc converter control, and the type of load on system stability are discussed. In order to improve system transient stability, nonlinear ac/dc converter control is introduced. The direct linearization method is used for control design. The dynamic analysis results show that these controls affect system stability in different ways. The parameter coordination of controllers are recommended based on the dynamic analysis. It is concluded from the present studies that system stability is improved by the coordination of control parameters and the nonlinear ac/dc converter control stabilize system oscillation caused by the load change and system fault efficiently.

  7. Failure analysis of a kind of low power connector

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yi-lin; ZENG Ning; XU Liang-jun; J(O)RGENS Stefan

    2007-01-01

    A kind of low power connector used e.g. in household appliances was partly burned in routine experiment. The heat sources were four paralleled contacts constructed by springs (Sn/CuSn-alloy) in socket and a plug sheet (Ni/Steel) while mating. The contact interfaces were detected by scanning electronic microscope (SEM) and X-ray energy dispersive spectroscopy (XEDS), obvious wear tracks and various contaminants, including element Si, Al, Na, K, S, C1, O, etc., were found. The contamination degrees on the four paralleled contacts .were different, so that the ratio of average contact resistance on the four contacts was about 5:8:3:1. The maximum contact resistance on contacts of the plug sheet reached 28 Ω. The main failure reasons were fretting and contamination between the contact interfaces. Fretting simulation showed that connection resistance of connectors was raised up, even to ohms level. When the current increased to 5 A, the socket housing was heated and decomposed. By the thermal analysis, it was estimated that the connector would be burned under the lower current if the current was not evenly distributed on the four paralleled contacts caused by uneven contamination. Improvement methods for connector failure are also discussed.

  8. A Study on Management Techniques of Power Telecommunication System by Reliability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.K.; Lee, B.S.; Woy, Y.H.; Oh, M.T.; Shin, M.T.; Kwan, O.G. [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center; Kim, K.H.; Kim, Y.H.; Lee, W.T.; Park, Y.H.; Lee, J.J.; Park, H.S.; Choi, M.C.; Kim, J. [Korea Electrotechnology Research Inst., Changwon (Korea, Republic of)

    1994-12-31

    Power telecommunication network is being increased rapidly in that expansion of power facilities according to the growth of electric power supply. The requirement of power facility and office automation and importance of communication services make it to complex and confusing to operate. And, for the sake of correspond to the change of power telecommunication network, effective operation and management is called for urgently. Therefore, the object of this study is to establish total reliability analysis system based on dependability, maintainability, cost effectiveness and replenishment for keep up reasonable reliability, support economical maintenance and reasonable planning of facility investment. And it will make effective management and administration system and schemes for total reliability improvement. (author). 44 refs., figs.

  9. Prolonged Living as a Refugee from the Area Around a Stricken Nuclear Power Plant Increases the Risk of Death.

    Science.gov (United States)

    Tanaka, Reiichiro

    2015-08-01

    Although it is well known that the Great East Japan Earthquake (March 11, 2011) resulted in a large number of disaster-related deaths, it is not common knowledge that the number of disaster-related deaths continues to increase, even four years after the earthquake, in Fukushima Prefecture, where the nuclear power plant accident occurred. There has been a lack of a minute and critical analysis for the causes for this continuous increase. In this report, the causes for the increase in disaster-related deaths in Fukushima Prefecture were analyzed by aggregating and comparing multiple data released by public organizations (the Reconstruction Agency, the National Police Agency, and Fukushima Prefecture), which may also have implications for developing response strategies to other disasters. The disaster-related death rate, the dead or missing rate, and the refugee rate (the number of disaster-related deaths, dead or missing persons, and refugees per 1,000 people) in each prefecture in stricken areas, and also each city, county, town, and village in Fukushima Prefecture, were calculated and compared with each other. The populations which were used for the calculation of each death rate in the area were based on the number of dead victims who had lived in the area when the earthquake occurred, regardless of where they were at the time of their death. The disaster-related death rate was higher than the dead or missing rate in the area around a stricken nuclear power plant in Fukushima Prefecture. These areas coincide exactly with the Areas under Evacuation Orders because of unsafe radiation levels. The external and internal radiation doses of most of the victims of the Great East Japan Earthquake have appeared not to be so high to harm their health, until now. The psychological stress associated with being displaced from one's home for a long time with an uncertain future may be the cause for these disaster-related deaths. There is an urgent need to recognize refugees

  10. Numerical Analysis of Powder Properties in Low Power Plasma Torch

    Institute of Scientific and Technical Information of China (English)

    YAN Zhi-jun; GAO Yang; HEI Zhu-kun; AN Lian-tong

    2004-01-01

    A mathematical model was presented to describe the particle trajectory, velocity and temperature properties in the low power plasma spraying torch (3.6 kW)in which powder particles were directly injected into the region between the cathode and anode. The results show that the characteristics of the particles by low power plasma spraying are similar to that by traditional APS( Atmosphere plasma spraying) in 40 kW. The velocities of the particles increase with the increase of inlet gas flow rate, current and percentage of nitrogen and hydrogen, while the temperature of the powder increase with the decrease of the gas flow rate and with the increase of current and percentage of nitrogen and hydrogen.

  11. Analysis of HCDA Power Excursions in KALIMER-150

    Energy Technology Data Exchange (ETDEWEB)

    Suk, S. D.; Lee, Y. B. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    A number of calculations have been performed to analyze the hypothetical super-prompt-critical power excursion of KALIMER-150 for various reactivity insertion rates, ranging from 10$/s up to 100$/s, using the VENUS-II code modified for the analysis of a metal fueled core. Parametric studies were also carried out in this study to investigate the sensitivity of the calculations to the initial power level and temperature distributions, which are among the major initial conditions of uncertainties expected to influence the analysis results Some of the major changes made in this study to apply the VENUS-II code to the CDA analysis of the KALIMER-150 include the reactivity feedback models and the equations of state of pressure-energy density relationship for the metallic fuel. The equations of state were derived for the saturated-vapor as well as the single phase liquid of the metallic uranium fuel.

  12. Attenuated Increase in Maximal Force of Rat Medial Gastrocnemius Muscle after Concurrent Peak Power and Endurance Training

    Directory of Open Access Journals (Sweden)

    Regula Furrer

    2013-01-01

    Full Text Available Improvement of muscle peak power and oxidative capacity are generally presumed to be mutually exclusive. However, this may not be valid by using fibre type-specific recruitment. Since rat medial gastrocnemius muscle (GM is composed of high and low oxidative compartments which are recruited task specifically, we hypothesised that the adaptive responses to peak power training were unaffected by additional endurance training. Thirty rats were subjected to either no training (control, peak power training (PT, or both peak power and endurance training (PET, which was performed on a treadmill 5 days per week for 6 weeks. Maximal running velocity increased 13.5% throughout the training and was similar in both training groups. Only after PT, GM maximal force was 10% higher than that of the control group. In the low oxidative compartment, mRNA levels of myostatin and MuRF-1 were higher after PT as compared to those of control and PET groups, respectively. Phospho-S6 ribosomal protein levels remained unchanged, suggesting that the elevated myostatin levels after PT did not inhibit mTOR signalling. In conclusion, even by using task-specific recruitment of the compartmentalized rat GM, additional endurance training interfered with the adaptive response of peak power training and attenuated the increase in maximal force after power training.

  13. Attenuated Increase in Maximal Force of Rat Medial Gastrocnemius Muscle after Concurrent Peak Power and Endurance Training

    Science.gov (United States)

    Furrer, Regula; Jaspers, Richard T.; Baggerman, Hein L.; Bravenboer, Nathalie; Lips, Paul; de Haan, Arnold

    2013-01-01

    Improvement of muscle peak power and oxidative capacity are generally presumed to be mutually exclusive. However, this may not be valid by using fibre type-specific recruitment. Since rat medial gastrocnemius muscle (GM) is composed of high and low oxidative compartments which are recruited task specifically, we hypothesised that the adaptive responses to peak power training were unaffected by additional endurance training. Thirty rats were subjected to either no training (control), peak power training (PT), or both peak power and endurance training (PET), which was performed on a treadmill 5 days per week for 6 weeks. Maximal running velocity increased 13.5% throughout the training and was similar in both training groups. Only after PT, GM maximal force was 10% higher than that of the control group. In the low oxidative compartment, mRNA levels of myostatin and MuRF-1 were higher after PT as compared to those of control and PET groups, respectively. Phospho-S6 ribosomal protein levels remained unchanged, suggesting that the elevated myostatin levels after PT did not inhibit mTOR signalling. In conclusion, even by using task-specific recruitment of the compartmentalized rat GM, additional endurance training interfered with the adaptive response of peak power training and attenuated the increase in maximal force after power training. PMID:23509812

  14. Kysat-2 electrical power system design and analysis

    Science.gov (United States)

    Molton, Brandon L.

    In 2012, Kentucky Space, LLC was offered the opportunity to design KYSat-2, a CubeSat mission which utilizes an experimental stellar-tracking camera system to test its effectiveness of determining the spacecraft's attitude while on orbit. Kentucky Space contracted Morehead State University to design the electrical power system (EPS) which will handle all power generation and power management and distribution to each of the KYSat-2 subsystems, including the flight computer, communications systems, and the experimental payload itself. This decision came as a result of the success of Morehead State's previous CubeSat mission, CXBN, which utilized a custom built power system and successfully launched in 2011. For the KYSat-2 EPS to be successful, it was important to design a system which was efficient enough to handle the power limitations of the space environment and robust enough to handle the challenges of powering a spacecraft on orbit. The system must be developed with a positive power budget, generating and storing more power than will be stored by KYSat-2 over mission lifetime. To accomplish this goal, the use of deployable solar panels has been utilized to double the usable surface area of the satellite for power generation, effectively doubling the usable power of the satellite system on orbit. The KYSat-2 EPS includes of set of gold plated deployable solar panels utilizing solar cells with a 26% efficiency. Power generated by this system is fed into a shunt regulator circuit which regulates the voltage generated to be stored in a 3-cell series battery pack. Stored powered is maintained using a balancing circuit which increases the efficiency and lifetime of the cells on-orbit. Power distribution includes raw battery voltage, four high-power outputs (two 5V and two 3.3 V) and a low-noise, low power 3.3V output for use with noise sensitive devices, such as microcontrollers. The solar panel deployment system utilizes the nichrome wire which draws current

  15. Stochastic Modeling and Analysis of Power System with Renewable Generation

    DEFF Research Database (Denmark)

    Chen, Peiyuan

    of a substation transformer is determined by the sum of the maximum loading at individual radial feeders while assuming no generation output from local generators. However, such a deterministic analysis does not provide a realistic evaluation of system steady-state performance. A more realistic evaluation can...... that minimizes the expectation of power losses of a 69-bus distribution system by controlling the power factor of WTs. The optimization is subjected to the probabilistic constraints of bus voltage and line current. The algorithm combines a constrained nonlinear optimization algorithm and a Monte Carlo based PLF...

  16. Power Estimation for Gene-Longevity Association Analysis Using Concordant Twins

    DEFF Research Database (Denmark)

    Tan, Qihua; Zhao, Jing Hua; Kruse, Torben A

    2014-01-01

    Statistical power is one of the major concerns in genetic association studies. Related individuals such as twins are valuable samples for genetic studies because of their genetic relatedness. Phenotype similarity in twin pairs provides evidence of genetic control over the phenotype variation...... in a population. The genetic association study on human longevity, a complex trait that is under control of both genetic and environmental factors, has been confronted by the small sample sizes of longevity subjects which limit statistical power. Twin pairs concordant for longevity have increased probability...... for carrying beneficial genes and thus are useful samples for gene-longevity association analysis. We conducted a computer simulation to estimate the power of association study using longevity concordant twin pairs. We observed remarkable power increases in using singletons from longevity concordant twin pairs...

  17. Living near nuclear power plants and thyroid cancer risk: A systematic review and meta-analysis.

    Science.gov (United States)

    Kim, Jaeyoung; Bang, Yejin; Lee, Won Jin

    2016-02-01

    There has been public concern regarding the safety of residing near nuclear power plants, and the extent of risk for thyroid cancer among adults living near nuclear power plants has not been fully explored. In the present study, a systematic review and meta-analysis of epidemiologic studies was conducted to investigate the association between living near nuclear power plants and the risk of thyroid cancer. A comprehensive literature search was performed on studies published up to March 2015 on the association between nuclear power plants and thyroid cancer risk. The summary standardized incidence ratio (SIR), standardized mortality ratio (SMR), and 95% confidence intervals (CIs) were calculated using a random-effect model of meta-analysis. Sensitivity analyses were performed by study quality. Thirteen studies were included in the meta-analysis, covering 36 nuclear power stations in 10 countries. Overall, summary estimates showed no significant increased thyroid cancer incidence or mortality among residents living near nuclear power plants (summary SIR=0.98; 95% CI 0.87-1.11, summary SMR=0.80; 95% CI 0.62-1.04). The pooled estimates did not reveal different patterns of risk by gender, exposure definition, or reference population. However, sensitivity analysis by exposure definition showed that living less than 20 km from nuclear power plants was associated with a significant increase in the risk of thyroid cancer in well-designed studies (summary OR=1.75; 95% CI 1.17-2.64). Our study does not support an association between living near nuclear power plants and risk of thyroid cancer but does support a need for well-designed future studies.

  18. Monitoring applications of power generators for the increase of energy efficiency using novel fiber optical sensors

    Science.gov (United States)

    Villnow, Michael; Willsch, Michael; Bosselmann, Thomas; Schmauss, Bernhard

    2011-05-01

    To verify optimization measures of power generators to improve the energy efficiency and to monitor critical parameters, fiber optical sensors have been developed and investigated. A fiber optical hot wire anemometer based on the thermooptic effect of Fiber Bragg Gratings was investigated to measure the flow distribution along the stator core. Fiber optical magnetic field sensors, based on the strain-optic effect of FBGs, were used to measure the magnetic field distribution on the end windings of a power generator. A novel fiber-optical accelerometer was used to measure the end winding vibrations. In this paper the functionality of each sensor is described and results of field test under real conditions are shown and discussed.

  19. Informed Conditioning on Clinical Covariates Increases Power in Case-Control Association Studies

    OpenAIRE

    Zaitlen, Noah; Lindstroem, Sara; Pasaniuc, Bogdan; Cornelis, Marilyn; Genovese, Giulio; Pollack, Samuela; Barton, Anne; Bickeboeller, Heike; Donald W. Bowden; Eyre, Steve; Barry I Freedman; Friedman, David J.; Field, John K.; Groop, Leif; Haugen, Aage

    2012-01-01

    Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI), smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from low-BMI cases are larger than those estimated from high-BMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals...

  20. Increasing the Performance and Reliability of Power Boiler by Monitoring Thermal and Strength Parameters

    OpenAIRE

    Sobota Tomasz

    2017-01-01

    The paper presents a method for determination of thermo-flow parameters for steam boilers. This method allows to perform the calculations of the boiler furnace chamber and heat flow rates absorbed by superheater stages. These parameters are important for monitoring the performance of the power unit. Knowledge of these parameters allows determining the degree of the furnace chamber slagging. The calculation can be performed in online mode and use to monitoring of steam boiler. The presented me...

  1. The increasing importance of power electronics; Die wachsende Bedeutung der Leistungselektronik. Stromerzeugung, -uebertragung und Stromverteilung sind heute ohne Silizium kaum denkbar

    Energy Technology Data Exchange (ETDEWEB)

    Baumberger, H.; Steimer, P. [ABB Schweiz AG, Turgi (Switzerland)

    2010-07-01

    This article takes a look at the importance today of silicon in power generation, power transmission and power distribution. Also, the importance of this semiconductor as an important component in systems that can increase the efficiency of power use is discussed. Various requirements placed on power electronics are examined, both in the areas of control and protection. The cooling required by such high-power semiconductors and the possibilities of realising it are discussed. Their use in the power generation area, for instance in wind power, photovoltaics and tidal power stations is reviewed, as are applications in pump-storage power stations. Along with power transmission applications, reactive power and energy storage applications are discussed. The article is rounded off with a review of the use of power electronics in consumer and industrial applications such as variable speed drives, mains voltage stabilisation and uninterruptible power supplies.

  2. Industry perspectives on increasing the efficiency of coal-fired power generation

    Energy Technology Data Exchange (ETDEWEB)

    Torrens, I.M. [Shell Coal International, London (United Kingdom); Stenzel, W.C.

    1997-12-31

    Independent power producers will build a substantial fraction of expected new coal-fired power generation in developing countries over the coming decades. To reduce perceived risk and obtain financing for their projects, they are currently building and plan to continue to build subcritical coal-fired plants with generating efficiency below 40%. Up-to-date engineering assessment leads to the conclusion that supercritical generating technology, capable of efficiencies of up to 45%, can produce electricity at a lower total cost than conventional plants. If such plants were built in Asia over the coming decades, the savings in carbon dioxide emissions over their lifetime would be measured in billions of tons. IPPs perceive supercritical technology as riskier and higher cost than conventional technology. The truth needs to be confirmed by discussions with additional experienced power engineering companies. Better communication among the interested parties could help to overcome the IPP perception issue. Governments working together with industry might be able to identify creative financing arrangements which can encourage the use of more efficient pulverized clean coal technologies, while awaiting the commercialization of advanced clean coal technologies like gasification combined cycle and pressurized fluidized bed combustion.

  3. Solar Stirling power generation - Systems analysis and preliminary tests

    Science.gov (United States)

    Selcuk, M. K.; Wu, Y.-C.; Moynihan, P. I.; Day, F. D., III

    1977-01-01

    The feasibility of an electric power generation system utilizing a sun-tracking parabolic concentrator and a Stirling engine/linear alternator is being evaluated. Performance predictions and cost analysis of a proposed large distributed system are discussed. Design details and preliminary test results are presented for a 9.5 ft diameter parabolic dish at the Jet Propulsion Laboratory (Caltech) Table Mountain Test Facility. Low temperature calorimetric measurements were conducted to evaluate the concentrator performance, and a helium flow system is being used to test the solar receiver at anticipated working fluid temperatures (up to 650 or 1200 C) to evaluate the receiver thermal performance. The receiver body is designed to adapt to a free-piston Stirling engine which powers a linear alternator assembly for direct electric power generation. During the next phase of the program, experiments with an engine and receiver integrated into the concentrator assembly are planned.

  4. Software and codes for analysis of concentrating solar power technologies.

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Clifford Kuofei

    2008-12-01

    This report presents a review and evaluation of software and codes that have been used to support Sandia National Laboratories concentrating solar power (CSP) program. Additional software packages developed by other institutions and companies that can potentially improve Sandia's analysis capabilities in the CSP program are also evaluated. The software and codes are grouped according to specific CSP technologies: power tower systems, linear concentrator systems, and dish/engine systems. A description of each code is presented with regard to each specific CSP technology, along with details regarding availability, maintenance, and references. A summary of all the codes is then presented with recommendations regarding the use and retention of the codes. A description of probabilistic methods for uncertainty and sensitivity analyses of concentrating solar power technologies is also provided.

  5. Betweenness as a Tool of Vulnerability Analysis of Power System

    Science.gov (United States)

    Rout, Gyanendra Kumar; Chowdhury, Tamalika; Chanda, Chandan Kumar

    2016-12-01

    Complex network theory finds its application in analysis of power grid as both share some common characteristics. By using this theory finding critical elements in power network can be achieved. As vulnerabilities of elements of the network decide the vulnerability of the total network, in this paper, vulnerability of each element is studied using two complex network models—betweenness centrality and extended betweenness. The betweenness centrality considers only topological structure of power system whereas extended betweenness is based on both topological and physical properties of the system. In the latter case, some of the electrical properties such as electrical distance, line flow limits, transmission capacities of lines and PTDF matrix are included. The standard IEEE 57 bus system has been studied based upon the above mentioned indices and following conclusions have been discussed.

  6. Thermodynamic analysis of Thermophotovoltaic Efficiency and Power Density Tradeoffs

    Energy Technology Data Exchange (ETDEWEB)

    P.F. Baldasara; J.E. Reynolds; G.W. Charache; D.M. DePoy; C.T. Ballinger; T. Donovan; J.M. Borrego

    2000-02-22

    This report presents an assessment of the efficiency and power density limitations of thermophotovoltaic (TPV) energy conversion systems for both ideal (radiative-limited) and practical (defect-limited) systems. Thermodynamics is integrated into the unique process physics of TPV conversion, and used to define the intrinsic tradeoff between power density and efficiency. The results of the analysis reveal that the selection of diode bandgap sets a limit on achievable efficiency well below the traditional Carnot level. In addition it is shown that filter performance dominates diode performance in any practical TPV system and determines the optimum bandgap for a given radiator temperature. It is demonstrated that for a given radiator temperature, lower bandgap diodes enable both higher efficiency and power density when spectral control limitations are included. The goal of this work is to provide a better understanding of the basic system limitations that will enable successful long-term development of TPV energy conversion technology.

  7. Windfarm Generation Assessment for Reliability Analysis of Power Systems

    DEFF Research Database (Denmark)

    Barberis Negra, Nicola; Bak-Jensen, Birgitte; Holmstrøm, O.

    2007-01-01

    Due to the fast development of wind generation in the past ten years, increasing interest has been paid to techniques for assessing different aspects of power systems with a large amount of installed wind generation. One of these aspects concerns power system reliability. Windfarm modelling plays...... in a reliability model and the generation of a windfarm is evaluated by means of sequential Monte Carlo simulation. Results are used to analyse how each mentioned Factor influences the assessment, and why and when they should be included in the model....

  8. Windfarm Generation Assessment for ReliabilityAnalysis of Power Systems

    DEFF Research Database (Denmark)

    Negra, Nicola Barberis; Holmstrøm, Ole; Bak-Jensen, Birgitte

    2007-01-01

    Due to the fast development of wind generation in the past ten years, increasing interest has been paid to techniques for assessing different aspects of power systems with a large amount of installed wind generation. One of these aspects concerns power system reliability. Windfarm modelling plays...... in a reliability model and the generation of a windfarm is evaluated by means of sequential Monte Carlo simulation. Results are used to analyse how each mentioned Factor influences the assessment, and why and when they should be included in the model....

  9. High-resolution Fourier transform ion cyclotron resonance mass spectrometry with increased throughput for biomolecular analysis.

    Science.gov (United States)

    Nagornov, Konstantin O; Gorshkov, Mikhail V; Kozhinov, Anton N; Tsybin, Yury O

    2014-09-16

    A multielectrode ion cyclotron resonance (ICR) cell, herein referred to as the "4X cell", for signal detection at the quadruple frequency multiple was implemented and characterized on a commercial 10 T Fourier transform ICR mass spectrometer (FT-ICR MS). Notably, with the 4X cell operating at a 10 T magnetic field we achieved a 4-fold increase in MS acquisition rate per unit of resolving power for signal detection periods typically employed in FTMS, viz., shorter than 6 s. Effectively, the obtained resolution performance represents the limit of the standard measurement principle with dipolar signal detection and FT signal processing at an equivalent magnetic field of 40 T. In other words, the achieved resolving powers are 4 times higher than those provided by 10 T FT-ICR MS with a standard ICR cell. For example, resolving powers of 170,000 and 70,000 were obtained in magnitude-mode Fourier spectra of 768 and 192 ms apodized transient signals acquired for a singly charged fluorinated phosphazine (m/z 1422) and a 19-fold charged myoglobin (MW 16.9 kDa), respectively. In peptide analysis, the baseline-resolved isotopic fine structures were obtained with as short as 768 ms transients. In intact protein analysis, the average resolving power of 340,000 across the baseline-resolved (13)C isotopic pattern of multiply charged ions of bovine serum albumin was obtained with 1.5 s transients. The dynamic range and the mass measurement accuracy of the 4X cell were found to be comparable to the ones obtained for the standard ICR cell on the same mass spectrometer. Overall, the reported results validate the advantages of signal detection at frequency multiples for increased throughput in FT-ICR MS, essential for numerous applications with time constraints, including proteomics.

  10. Electromechanical modeling of a honeycomb core integrated vibration energy converter with increased specific power for energy harvesting applications

    Science.gov (United States)

    Chandrasekharan, Nataraj

    Innovation in integrated circuit technology along with improved manufacturing processes has resulted in considerable reduction in power consumption of electromechanical devices. Majority of these devices are currently powered by batteries. However, the issues posed by batteries, including the need for frequent battery recharge/replacement has resulted in a compelling need for alternate energy to achieve self-sufficient device operation or to supplement battery power. Vibration based energy harvesting methods through piezoelectric transduction provides with a promising potential towards replacing or supplementing battery power source. However, current piezoelectric energy harvesters generate low specific power (power-to-weight ratio) when compared to batteries that the harvesters seek to replace or supplement. In this study, the potential of integrating lightweight cellular honeycomb structures with existing piezoelectric device configurations (bimorph) to achieve higher specific power is investigated. It is shown in this study that at low excitation frequency ranges, replacing the solid continuous substrate of a conventional piezoelectric bimorph with honeycomb structures of the same material results in a significant increase in power-to-weight ratio of the piezoelectric harvester. In order to maximize the electrical response of vibration based power harvesters, the natural frequency of these harvesters is designed to match the input driving frequency. The commonly used technique of adding a tip mass is employed to lower the natural frequency (to match driving frequency) of both, solid and honeycomb substrate bimorphs. At higher excitation frequency, the natural frequency of the traditional solid substrate bimorph can only be altered (to match driving frequency) through a change in global geometric design parameters, typically achieved by increasing the thickness of the harvester. As a result, the size of the harvester is increased and can be disadvantageous

  11. Scaling range of power laws that originate from fluctuation analysis.

    Science.gov (United States)

    Grech, Dariusz; Mazur, Zygmunt

    2013-05-01

    We extend our previous study of scaling range properties performed for detrended fluctuation analysis (DFA) [Physica A 392, 2384 (2013)] to other techniques of fluctuation analysis (FA). The new technique, called modified detrended moving average analysis (MDMA), is introduced, and its scaling range properties are examined and compared with those of detrended moving average analysis (DMA) and DFA. It is shown that contrary to DFA, DMA and MDMA techniques exhibit power law dependence of the scaling range with respect to the length of the searched signal and with respect to the accuracy R^{2} of the fit to the considered scaling law imposed by DMA or MDMA methods. This power law dependence is satisfied for both uncorrelated and autocorrelated data. We find also a simple generalization of this power law relation for series with a different level of autocorrelations measured in terms of the Hurst exponent. Basic relations between scaling ranges for different techniques are also discussed. Our findings should be particularly useful for local FA in, e.g., econophysics, finances, or physiology, where the huge number of short time series has to be examined at once and wherever the preliminary check of the scaling range regime for each of the series separately is neither effective nor possible.

  12. XLPE power cables with optimised conductor properties. Increasing transmission capacity; VPE-Hochleistungskabel mit optimierten Leitereigenschaften. Erhoehung der Uebertragungsleistung

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Sigurdur A. [Suedkabel GmbH, Mannheim (Germany)

    2009-11-02

    Conductors laid up of segments in combination with additional design measures can considerably increase the current carrying capacity of XLPE power cables. Compared to conductors of circular stranded design without the described improving methods the permissible transmission rating will be raised by approx. 15%. (orig.)

  13. Metrology Optical Power Budgeting in SIM Using Statistical Analysis Techniques

    Science.gov (United States)

    Kuan, Gary M

    2008-01-01

    The Space Interferometry Mission (SIM) is a space-based stellar interferometry instrument, consisting of up to three interferometers, which will be capable of micro-arc second resolution. Alignment knowledge of the three interferometer baselines requires a three-dimensional, 14-leg truss with each leg being monitored by an external metrology gauge. In addition, each of the three interferometers requires an internal metrology gauge to monitor the optical path length differences between the two sides. Both external and internal metrology gauges are interferometry based, operating at a wavelength of 1319 nanometers. Each gauge has fiber inputs delivering measurement and local oscillator (LO) power, split into probe-LO and reference-LO beam pairs. These beams experience power loss due to a variety of mechanisms including, but not restricted to, design efficiency, material attenuation, element misalignment, diffraction, and coupling efficiency. Since the attenuation due to these sources may degrade over time, an accounting of the range of expected attenuation is needed so an optical power margin can be book kept. A method of statistical optical power analysis and budgeting, based on a technique developed for deep space RF telecommunications, is described in this paper and provides a numerical confidence level for having sufficient optical power relative to mission metrology performance requirements.

  14. Power Quality Analysis Using Bilinear Time-Frequency Distributions

    Directory of Open Access Journals (Sweden)

    Sha'ameri AhmadZuri

    2010-01-01

    Full Text Available Abstract Bilinear time-frequency distributions (TFDs are powerful techniques that offer good time and frequency resolution of time-frequency representation (TFR. It is very appropriate to analyze power quality signals which consist of nonstationary and multi-frequency components. However, the TFDs suffer from interference because of cross-terms. Many TFDs have been implemented, and there is no fixed window or kernel that can remove the cross-terms for all types of signals. In this paper, the bilinear TFDs are implemented to analyze power quality signals such as smooth-windowed Wigner-Ville distribution (SWWVD, Choi-Williams distribution (CWD, B-distribution (BD, and modified B-distribution (MBD. The power quality signals focused are swell, sag, interruption, harmonic, interharmonic, and transient based on IEEE Std, 1159-1995. A set of performance measures is defined and used to compare the TFRs. It shows that SWWVD presents the best performance and is selected for power quality signal analysis. Thus, an adaptive optimal kernel SWWVD is designed to determine the separable kernel automatically from the input signal.

  15. Performance Analysis of a Hybrid Power Cutting System for Roadheader

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2017-01-01

    Full Text Available An electrohydraulic hybrid power cutting transmission system for roadheader under specific working condition was proposed in this paper. The overall model for the new system composed of an electric motor model, a hydraulic pump-motor model, a torsional planetary set model, and a hybrid power train model was established. The working mode characteristics were simulated under the conditions of taking the effect of cutting picks into account. The advantages of new hybrid power cutting system about the dynamic response under shock load were investigated compared with the traditional cutting system. The results illustrated that the hybrid power system had an obvious cushioning in terms of the dynamic load of cutting electric motor and planetary gear set. Besides, the hydraulic motor could provide an auxiliary power to improve the performance of the electric motor. With further analysis, a dynamic load was found to have a high relation to the stiffness and damping of coupling in the transmission train. The results could be a useful guide for the design of cutting transmission of roadheader.

  16. Increasing the Performance and Reliability of Power Boiler by Monitoring Thermal and Strength Parameters

    Directory of Open Access Journals (Sweden)

    Sobota Tomasz

    2017-01-01

    Full Text Available The paper presents a method for determination of thermo-flow parameters for steam boilers. This method allows to perform the calculations of the boiler furnace chamber and heat flow rates absorbed by superheater stages. These parameters are important for monitoring the performance of the power unit. Knowledge of these parameters allows determining the degree of the furnace chamber slagging. The calculation can be performed in online mode and use to monitoring of steam boiler. The presented method allows to the operation of steam boiler with high efficiency.

  17. Harmonic Analysis of Boolean Networks: Determinative Power and Perturbations

    CERN Document Server

    Heckel, Reinhard; Bossert, Martin

    2011-01-01

    Consider a large Boolean network with a feed forward structure. Given a probability distribution for the inputs, can one find-possibly small-collections of input nodes that determine the states of most other nodes in the network? To identify these nodes, a notion that quantifies the determinative power of an input over states in the network is needed. We argue that the mutual information (MI) between a subset of the inputs X = {X_1, ..., X_n} of node i and the function f_i(X)$ associated with node i quantifies the determinative power of this subset of inputs over node i. To study the relation of determinative power to sensitivity to perturbations, we relate the MI to measures of perturbations, such as the influence of a variable, in terms of inequalities. The result shows that, maybe surprisingly, an input that has large influence does not necessarily have large determinative power. The main tool for the analysis is Fourier analysis of Boolean functions. Whether a function is sensitive to perturbations or not...

  18. Bifurcation Analysis of a DC-DC Bidirectional Power Converter Operating with Constant Power Loads

    Science.gov (United States)

    Cristiano, Rony; Pagano, Daniel J.; Benadero, Luis; Ponce, Enrique

    Direct current (DC) microgrids (MGs) are an emergent option to satisfy new demands for power quality and integration of renewable resources in electrical distribution systems. This work addresses the large-signal stability analysis of a DC-DC bidirectional converter (DBC) connected to a storage device in an islanding MG. This converter is responsible for controlling the balance of power (load demand and generation) under constant power loads (CPLs). In order to control the DC bus voltage through a DBC, we propose a robust sliding mode control (SMC) based on a washout filter. Dynamical systems techniques are exploited to assess the quality of this switching control strategy. In this sense, a bifurcation analysis is performed to study the nonlinear stability of a reduced model of this system. The appearance of different bifurcations when load parameters and control gains are changed is studied in detail. In the specific case of Teixeira Singularity (TS) bifurcation, some experimental results are provided, confirming the mathematical predictions. Both a deeper insight in the dynamic behavior of the controlled system and valuable design criteria are obtained.

  19. Integrating engineering design improvements with exoelectrogen enrichment process to increase power output from microbial fuel cells

    Science.gov (United States)

    Borole, Abhijeet P.; Hamilton, Choo Y.; Vishnivetskaya, Tatiana A.; Leak, David; Andras, Calin; Morrell-Falvey, Jennifer; Keller, Martin; Davison, Brian

    Microbial fuel cells (MFC) hold promise as a green technology for bioenergy production. The challenge is to improve the engineering design while exploiting the ability of microbes to generate and transfer electrons directly to electrodes. A strategy using a combination of improved anode design and an enrichment process was formulated to improve power densities. The design was based on a flow-through anode with minimal dead volume and a high electrode surface area per unit volume. The strategy focused on promoting biofilm formation via a combination of forced flow through the anode, carbon limitation, and step-wise reduction of external resistance. The enrichment process resulted in development of exoelectrogenic biofilm communities dominated by Anaeromusa spp. This is the first report identifying organisms from the Veillonellaceae family in MFCs. The power density of the resulting MFC using a ferricyanide cathode reached 300 W m -3 net anode volume (3220 mW m -2), which is about a third of what is estimated to be necessary for commercial consideration. The operational stability of the MFC using high specific surface area electrodes was demonstrated by operating the MFC for a period of over four months.

  20. Increasing the reliability of power semiconductors using DAB-substrates; Steigerung der Zuverlaessigkeit von Leistungshalbleitern durch Verwendung von DAB-Substraten

    Energy Technology Data Exchange (ETDEWEB)

    Grieger, F.; Lindemann, A. [Magdeburg Univ. (Germany); Boettge, B.; Klengel, S.; Petzold, M. [Fraunhofer IWM, Halle an der Saale (Germany)

    2012-07-01

    Besides power electronic loads, power electronic sources for decentralised generation have established in the grid. In the smart grid, the use of power electronics will even increase because of the introduction of more HVDC transmission lines and the necessity to control power flows. This paper deals with direct aluminium bonded (DAB) substrates which can serve as carriers of power electronic components with further increased reliability as desirable for long-term usage in the smart grid. (orig.)

  1. Employing Power Graph Analysis to Facilitate Modeling Molecular Interaction Networks

    Directory of Open Access Journals (Sweden)

    Momchil Nenov

    2015-04-01

    Full Text Available Mathematical modeling is used to explore and understand complex systems ranging from weather patterns to social networks to gene-expression regulatory mechanisms. There is an upper limit to the amount of details that can be reflected in a model imposed by finite computational resources. Thus, there are methods to reduce the complexity of the modeled system to its most significant parameters. We discuss the suitability of clustering techniques, in particular Power Graph Analysis as an intermediate step of modeling.

  2. Nuclear power and the public: analysis of collected survey research

    Energy Technology Data Exchange (ETDEWEB)

    Melber, B.D.; Nealey, S.M.; Hammersla, J.; Rankin, W.L.

    1977-11-01

    This executive summary highlights the major findings of a comprehensive synthesis and analysis of over 100 existing surveys dealing with public attitudes toward nuclear power issues. Questions of immediate policy relevance to the nuclear debate are posed and answered on the basis of these major findings. For each issue area, those sections of the report in which more-detailed discussion and presentation of relevant data may be found are indicated.

  3. Fishing power increases from technological development in the Faroe Islands longline fishery

    NARCIS (Netherlands)

    Eigaard, O.R.; Thomsen, B.; Hovgaard, H.; Nielsen, A.; Rijnsdorp, A.D.

    2011-01-01

    During an effort-regulated period from 1996 to 2002, unregistered annual increases of 0.3% of hooks fished per day were demonstrated for the Faroe Islands longline fishery. However, annual increases were higher (1.5%) during a preceding total allowable catch regulated period, thereby invalidating an

  4. Shared genomic segment analysis: the power to find rare disease variants.

    Science.gov (United States)

    Knight, Stacey; Abo, Ryan P; Abel, Haley J; Neklason, Deborah W; Tuohy, Therese M; Burt, Randall W; Thomas, Alun; Camp, Nicola J

    2012-11-01

    Shared genomic segment (SGS) analysis uses dense single nucleotide polymorphism genotyping in high-risk (HR) pedigrees to identify regions of sharing between cases. Here, we illustrate the power of SGS to identify dominant rare risk variants. Using simulated pedigrees, we consider 12 disease models based on disease prevalence, minor allele frequency and penetrance to represent disease loci that explain 0.2-99.8% of total disease risk. Pedigrees were required to contain ≥ 15 meioses between all cases and to be HR based on significant excess of disease (P power for a single pedigree ranged widely. Nonetheless, fewer than 10 pedigrees were sufficient for excellent power in the majority of models. Power increased with the risk attributable to the disease locus, penetrance and the excess of disease in the pedigree. Sharing allowing for one sporadic case was uniformly more powerful than sharing using all cases. Furthermore, an SGS analysis using a large attenuated familial adenomatous polyposis pedigree identified a 1.96 Mb region containing the known causal APC gene with genome-wide significance. SGS is a powerful method for detecting rare variants and a valuable complement to genome-wide association studies and linkage analysis.

  5. COMPARATIVE ANALYSIS OF EV-MOGA AND GODLIKE MULTIOBJECTIVE EVOLUTIONARY ALGORITHMS FOR RISK BASED OPTIMAL POWER SCHEDULING OF A VIRTUAL POWER PLANT

    Directory of Open Access Journals (Sweden)

    Mahesh S. Narkhede

    2015-01-01

    Full Text Available An attempt has been made in this article to compare the performances of two multiobjective evolutionary algorithms namely ev-MOGA and GODLIKE. The performances of both are evaluated on risk based optimal power scheduling of virtual power plant. The risk based scheduling is proposed as a conflicting bi objective optimization problem with increased number of durations of day. Both the algorithms are elaborated in detail. Results based on the performance analysis are depicted at the end.

  6. Using public control genotype data to increase power and decrease cost of case-control genetic association studies.

    Science.gov (United States)

    Ho, Lindsey A; Lange, Ethan M

    2010-12-01

    Genome-wide association (GWA) studies are a powerful approach for identifying novel genetic risk factors associated with human disease. A GWA study typically requires the inclusion of thousands of samples to have sufficient statistical power to detect single nucleotide polymorphisms that are associated with only modest increases in risk of disease given the heavy burden of a multiple test correction that is necessary to maintain valid statistical tests. Low statistical power and the high financial cost of performing a GWA study remains prohibitive for many scientific investigators anxious to perform such a study using their own samples. A number of remedies have been suggested to increase statistical power and decrease cost, including the utilization of free publicly available genotype data and multi-stage genotyping designs. Herein, we compare the statistical power and relative costs of alternative association study designs that use cases and screened controls to study designs that are based only on, or additionally include, free public control genotype data. We describe a novel replication-based two-stage study design, which uses free public control genotype data in the first stage and follow-up genotype data on case-matched controls in the second stage that preserves many of the advantages inherent when using only an epidemiologically matched set of controls. Specifically, we show that our proposed two-stage design can substantially increase statistical power and decrease cost of performing a GWA study while controlling the type-I error rate that can be inflated when using public controls due to differences in ancestry and batch genotype effects.

  7. Power Spectrum Analysis of Three-Dimensional Redshift Surveys

    CERN Document Server

    Feldman, H A; Peacock, J A; Feldman, Hume A.; Kaiser, Nick; Peacock, John A.

    1994-01-01

    We develop a general method for power spectrum analysis of three dimensional redshift surveys. We present rigorous analytical estimates for the statistical uncertainty in the power and we are able to derive a rigorous optimal weighting scheme under the reasonable (and largely empirically verified) assumption that the long wavelength Fourier components are Gaussian distributed. We apply the formalism to the updated 1-in-6 QDOT IRAS redshift survey, and compare our results to data from other probes: APM angular correlations; the CfA and the Berkeley 1.2Jy IRAS redshift surveys. Our results bear out and further quantify the impression from e.g.\\ counts-in-cells analysis that there is extra power on large scales as compared to the standard CDM model with $\\Omega h\\simeq 0.5$. We apply likelihood analysis using the CDM spectrum with $\\Omega h$ as a free parameter as a phenomenological family of models; we find the best fitting parameters in redshift space and transform the results to real space. Finally, we calcul...

  8. Economic analysis of municipal wastewater utilization for thermoelectric power production

    Energy Technology Data Exchange (ETDEWEB)

    Safari, I.; Walker, M.; Abbasian, J.; Arastoopour, H.; Hsieh, M-K.; Theregowda, R.; Dzombak, D.; Miller, D.

    2011-01-01

    The thermoelectric power industry in the U.S. uses a large amount of freshwater. The large water demand is increasingly a problem, especially for new power plant development, as availability of freshwater for new uses diminishes in the United States. Reusing non-traditional water sources, such as treated municipal wastewater, provides one option to mitigate freshwater usage in the thermoelectric power industry. The amount of freshwater withdrawal that can be displaced with non-traditional water sources at a particular location requires evaluation of the water management and treatment requirements, considering the quality and abundance of the non-traditional water sources. This paper presents the development of an integrated costing model to assess the impact of degraded water treatment, as well as the implications of increased tube scaling in the main condenser. The model developed herein is used to perform case studies of various treatment, condenser cleaning and condenser configurations to provide insight into the ramifications of degraded water use in the cooling loops of thermoelectric power plants. Further, this paper lays the groundwork for the integration of relationships between degraded water quality, scaling characteristics and volatile emission within a recirculating cooling loop model.

  9. A performance analysis of solar chimney thermal power systems

    Directory of Open Access Journals (Sweden)

    Al-Dabbas Awwad Mohammed

    2011-01-01

    Full Text Available The objective of this study was to evaluate the solar chimney performance theoretically (techno-economic. A mathematical model was developed to estimate the following parameter: Power output, Pressure drop across the turbine, the max chimney height, Airflow temperature, and the overall efficiency of solar chimney. The mathematical model was validated with experimental data from the prototype in Manzanares power. It can be concluded that the differential pressure of collector-chimney transition section in the system, is increase with the increase of solar radiation intensity. The specific system costs are between 2000 Eur/kW and 5000 Eur/kW depending on the system size, system concept and storage size. Hence, a 50 MWe solar thermal power plant will cost 100-250 Eur million. At very good sites, today’s solar thermal power plants can generate electricity in the range of 0.15 Eur/kWh, and series production could soon bring down these costs below 0.10 Eur /kWh.

  10. Drivers for the Value of Demand Response under Increased Levels of Wind and Solar Power; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Elaine

    2015-07-30

    Demand response may be a valuable flexible resource for low-carbon electric power grids. However, there are as many types of possible demand response as there are ways to use electricity, making demand response difficult to study at scale in realistic settings. This talk reviews our state of knowledge regarding the potential value of demand response in several example systems as a function of increasing levels of wind and solar power, sometimes drawing on the analogy between demand response and storage. Overall, we find demand response to be promising, but its potential value is very system dependent. Furthermore, demand response, like storage, can easily saturate ancillary service markets.

  11. Does price efficiency increase with trading volume? Evidence of nonlinearity and power laws in ETFs

    Science.gov (United States)

    Caginalp, Gunduz; DeSantis, Mark

    2017-02-01

    Whether efficiency increases with increasing volume is an important issue that may illuminate trader strategies and distinguish between market theories. This relationship is tested using 124,236 daily observations comprising 68 large and liquid U.S. equity exchange traded funds (ETFs). ETFs have the advantage that efficiency can be measured in terms of the deviation between the trading price and the underlying net asset value that is reported each day. Our findings support the hypothesis that the relationship between volume and efficiency is nonlinear. Indeed, efficiency increases as volume increases from low to moderately high levels, but then decreases as volume increases further. The first part tends to support the idea that higher volume simply facilitates transactions and maintains efficiency, while the latter part, i.e., even higher volumes, supports the ansatz that increased volume is associated with increased speculation that ignores valuation and decreases efficiency. The results are consistent with the hypothesis that valuation is only part of the motivation for traders. Our methodology accounts for fund heterogeneity and contemporaneous correlations. Similar results are obtained when daily price volatility is introduced as an additional independent variable.

  12. Analysis of electrical tree propagation in XLPE power cable insulation

    Energy Technology Data Exchange (ETDEWEB)

    Bao Minghui, E-mail: baominghui@21cn.co [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan (China); Yin Xiaogen; He Junjia [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan (China)

    2011-04-01

    Electrical treeing is one of the major breakdown mechanisms for solid dielectrics subjected to high electrical stress. In this paper, the characteristics of electrical tree growth in XLPE samples have been investigated. XLPE samples are obtained from a commercial XLPE power cable, in which electrical trees have been grown from pin to plane in the frequency range of 4000-10,000 Hz, voltage range of 4-10 kV, and the distances between electrodes of 1 and 2 mm. Images of trees and their growing processes were taken by a CCD camera. The fractal dimensions of electric trees were obtained by using a simple box-counting technique. The results show that the tree growth rate and fractal dimension was bigger when the frequency or voltage was higher, or the distance between electrodes was smaller. Contrary to our expectation, it has been found that when the distance between electrodes changed from 1 to 2 mm, the required voltage of the similar electrical trees decreased only 1or 2 kV. In order to evaluate the difficulties of electrical tree propagation in different conditions, a simple energy threshold analysis method has been proposed. The threshold energy, which presents the minimum energy that a charge carrier in the well at the top of the tree should have to make the tree grow, has been computed considering the length of electrical tree, the fractal dimension, and the growth time. The computed results indicate that when one of the three parameters of voltage, frequency, and local electric field increase, the trends of energy threshold can be split into 3 regions.

  13. Development of an Axial Flux MEMS BLDC Micromotor with Increased Efficiency and Power Density

    Directory of Open Access Journals (Sweden)

    Xiaofeng Ding

    2015-06-01

    Full Text Available This paper presents a rigorous design and optimization of an axial flux microelectromechanical systems (MEMS brushless dc (BLDC micromotor with dual rotor improving both efficiency and power density with an external diameter of only around 10 mm. The stator is made of two layers of windings by MEMS technology. The rotor is developed by film permanent magnets assembled over the rotor yoke. The characteristics of the MEMS micromotor are analyzed and modeled through a 3-D magnetic equivalent circuit (MEC taking the leakage flux and fringing effect into account. Such a model yields a relatively accurate prediction of the flux in the air gap, back electromotive force (EMF and electromagnetic torque, whilst being computationally efficient. Based on 3-D MEC model the multi-objective firefly algorithm (MOFA is developed for the optimal design of this special machine. Both 3-D finite element (FE simulation and experiments are employed to validate the MEC model and MOFA optimization design.

  14. Mitigating an increase of specific power consumption in a cryogenic air separation unit at reduced oxygen production

    Science.gov (United States)

    Singla, Rohit; Chowdhury, Kanchan

    2017-02-01

    Specific power consumed in a Linde double column air separation unit (ASU) increases as the quantity of oxygen produced at a given purity is decreased due to the changes of system requirement or market demand. As the plant operates in part load condition, the specific power consumption (SPC) increases as the total power consumption remains the same. In order to mitigate the increase of SPC at lower oxygen production, the operating pressure of high pressure column (HPC) can be lowered by extending the low pressure column (LPC) by a few trays and adding a second reboiler. As the duty of second reboiler in LPC is increased, the recovery of oxygen decreases with a lowering of the HPC pressure. This results in mitigation of the increase of SPC of the plant. A Medium pressure ASU with dual reboiler that produces pressurised gaseous and liquid products of oxygen and nitrogen is simulated in Aspen Hysys 8.6®, a commercial process simulator to determine SPC at varying oxygen production. The effects of reduced pressure of air feed into the cold box on the size of heat exchangers (HX) are analysed. Operation strategy to obtain various oxygen production rates at varying demand is also proposed.

  15. Large scale exchange of balancing power between Norway and Europe: analysis of impacts

    Energy Technology Data Exchange (ETDEWEB)

    Graabak, Ingeborg; Skjelbred, Hans Ivar

    2012-07-01

    This report is from at study in Centre for environmental design of renewable energy (CEDREN). (The objective of the analysis is to show the impacts on the European power system if Norwegian hydropower is used for large-scale balancing. A special focus in on possible reductions of the CO{sub 2} emissions. A scenario methodology is used to explore different future developments of the power systems. The analysis is performed by the EMPS-model. All expected impacts on the European power system where observed: the Norwegian hydro power system worked as a pump-storage, the surplus in the production, the rationing of the demand and the CO{sub 2} emissions from the European power production were reduced. However, this report must mainly be regarded as preliminary analysis of the impacts of Norway as a 'green battery' for Europe. The work has given increased insight in necessary improvements in the design of the cases for analysis, the use og the EMPS as well as the implementation of the model before it is possible to finally quantify the impacts. The work will be brought further in other projects. (Author)

  16. Analysis of chinese Power Market in 2007 and Its Forecast

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Power supply and demand in January-September, 2007 Since 2007, the national economy developed continuously, showing a situation of rapid growth, more optimized structure, increased efficiency and improvement of people's livelihood. In the first three quarters, GDP achieved 16.6043 trillion Yuan, and its year-on-year growth rate was 11.5%; the growth rate was 0.7 percentage points higher than that of the previous year.

  17. Increase in the number of distributed power generation installations in electricity distribution grids - Literature; Zunahme der dezentralen Energieerzeugungsanlagen in elektrischen Verteilnetzen: Literatur

    Energy Technology Data Exchange (ETDEWEB)

    Gottsponer, O.; Mauchle, P.

    2003-07-01

    This is the tenth and last part of a final report for the Swiss Federal Office of Energy (SFOE) on a project that looked into potential problems relating to the Swiss electricity distribution grid with respect to the increasing number of distributed power generation facilities being put into service. The identification of special conditions for the grid's operation and future development that take increasing decentralised power production into account are discussed. The results of the project activities encompass the analysis and evaluation of various problem areas associated with planning and management of the grid during normal operation and periods of malfunction, as well as required modifications to safety systems and grid configurations. This ninth appendix to the main report presents an overview and details of the literature and internet sources used in the project. Also, similar projects that discuss the problem area dealt with are briefly described. These include the Dispower, EDIson, DEMS, AMOEVES and ELSAD projects.

  18. Steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Fang, Jiakun; Li, Jinghua

    2016-01-01

    Nowadays, the electric power system and natural gas network are becoming increasingly coupled and interdependent. A harmonized integration of natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables in terms of system...... flexibility. This work focuses on the steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion. A unified energy flow formulation is developed to describe the nodal balance and branch flow in both systems and it is solved with the Newton...... series of wind power and power load are used to investigate the mitigation effect of the integrated energy system. At last, the effect of wind power and power demand on the output of Power to Gas (P2G) and gas-fired power generation (GPG) has also been investigated....

  19. Information or prices, which is most powerful in increasing consumer demand for organic vegetables?

    DEFF Research Database (Denmark)

    Smed, Sinne; Andersen, Laura Mørch

    2012-01-01

    that link health and the consumption of organic vegetables will increase consumption. The results are important for firms and producers who want to successfully target information to different consumer groups with the aim of increasing the market share for organic food.......Based on a unique and very detailed panel dataset covering consumption of organically and conventionally produced vegetables in the years 2005 - 2007, we examine the effects of information about positive health effects of consuming organic vegetables and information about negative health effects...

  20. Jacobian integration method increases the statistical power to measure gray matter atrophy in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Kunio Nakamura

    2014-01-01

    Full Text Available Gray matter atrophy provides important insights into neurodegeneration in multiple sclerosis (MS and can be used as a marker of neuroprotection in clinical trials. Jacobian integration is a method for measuring volume change that uses integration of the local Jacobian determinants of the nonlinear deformation field registering two images, and is a promising tool for measuring gray matter atrophy. Our main objective was to compare the statistical power of the Jacobian integration method to commonly used methods in terms of the sample size required to detect a treatment effect on gray matter atrophy. We used multi-center longitudinal data from relapsing–remitting MS patients and evaluated combinations of cross-sectional and longitudinal pre-processing with SIENAX/FSL, SPM, and FreeSurfer, as well as the Jacobian integration method. The Jacobian integration method outperformed these other commonly used methods, reducing the required sample size by a factor of 4–5. The results demonstrate the advantage of using the Jacobian integration method to assess neuroprotection in MS clinical trials.

  1. Method for Increasing the Efficiency of Automatic Fire Extinguish System at Objects Of Power

    Directory of Open Access Journals (Sweden)

    Dmitrienko Margarita

    2015-01-01

    Full Text Available Operation of energy facilities requires compliance with all safety standards, and especially fire safety. Emergency situations that arise when operated the power equipment damage not only the objects of the technosphere but also the environment. In recent years, can be noted a trend of quite intensive development of technological bases of technology water mist fire extinguishing. Using the methods of optical panoramic imaging PIV, IPI and the method of high-speed video recording were performed the experimental studies of the characteristics of evaporation of large single water droplets as they pass through the flames of oil and oil products with varying parameters of the processes (the initial size of 2–6 mm, the rate of 2–4 m/s and the temperature of water drops 290–300 K, the temperature of the combustion products 185–2073 K. Was established decisive influence droplet size, velocities at which droplets enter the gaseous medium, the initial water temperature on heating rate and evaporation of droplets in a stream of high-temperature combustion products.

  2. Rerouting end-face-TIR capable rays to significantly increase evanescent wave signal power

    Institute of Scientific and Technical Information of China (English)

    Jianjun Ma; Yasser Chiniforooshan; Huacai Chen; Jiahua Chen; Wojtek J. Bock; Andrea Cusano

    2011-01-01

    The critical findings associated with end-face total internal reflection (TIR) phenomemon we proved before are reported. In particular, these findings reveal that the end-face-TIR capable rays experience enormous mode mixing when encountering a roughened end face. As a result, 94% of the overall detectable power is contributed by this effect. With a smooth fiber end face, this figure is mere 52%. We interpret the mechanism behind these unusual phenomena and its significance for the performance enhancement of fiber optic evanescent wave sensor.%@@ The critical findings associated with end-face total internal reflection (TIR) phenomemon we proved before are reported, In particular, these findings reveal that the end-face-TIR capable rays experience enormous mode mixing when encountering a roughened end face.As a result, 94Vo of the overall detectable poweris contributed by this effect.With a smooth fiber end face, this figure is mere 52%.We interpret the mechanism behind these unusual phenomena and its significance for the performance enhancement of fiber optic evanescent wave sensor.

  3. Analysis of engineering cycles power, refrigerating and gas liquefaction plant

    CERN Document Server

    Haywood, R W

    1991-01-01

    Extensively revised, updated and expanded, the fourth edition of this popular text provides a rigorous analytical treatment of modern energy conversion plant. Notable for both its theoretical and practical treatment of conventional and nuclear power plant, and its studies of refrigerating and gas-liquefaction plant. This fourth edition now includes material on topics of increasing concern in the fields of energy 'saving' and reduction of environmental pollution. This increased coverage deals specifically with the following areas: CHP (cogeneration) plant, studies of both gas and coal burning p

  4. Power plant selection in a carbon constrained world the TERA (technoeconomic environmental risk analysis)

    Institute of Scientific and Technical Information of China (English)

    Stephen Ogaji; Pericles Pilidis; Vishal Sethi

    2009-01-01

    There is an increasing concern that current trends of consumption of natural resources cannot continue. It is imperative that major targeted investments are made into economical and reliable environment friendly propulsion and power solutions. Many novel and promising concepts are being proposed. The selection of the best candidates to pursue for investment becomes a very difficult choice.A detailed TERA (techno-economic environmental risk analysis) framework is described here to quantify risks and to compare and rank competing schemes on a formal and consistent basis. This technique is based on detailed and rigorous thermodynamic representations of power plants. A layer of environment, economic, weather and other models to describe the appropriate local conditions is superimposed to this.The outcome is a techno-economic environmental risk analysis framework with appropriate detail of each power plant as applied to the appropriate conditions. The results for each concept can then be compared and contrasted to make appropriate selections.

  5. Increase in the number of distributed power generation installations in electricity distribution grids - Main report; Zunahme der dezentralen Energieerzeugungsanlagen in elektrischen Verteilnetzen

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, G.; Mauchle, P. [Schnyder Ingenieure AG, Huenenberg (Switzerland); Hoeckel, M.; Luschinger, P. [Berner Fachhochschule (HTI Biel), Biel (Switzerland); Firtz, O.; Haederli, C.; Jaggy, E. [ABB Schweiz AG, Corporate Research, Baden-Daettwil (Switzerland)

    2003-07-01

    This first part of a ten-part final report for the Swiss Federal Office of Energy (SFOE) presents the main findings of a project that looked into potential problems relating to the Swiss electricity distribution grid with respect to the increasing number of distributed power generation facilities being put into service. The identification of special conditions for the grid's operation and future development that take increasing decentralised power production into account are discussed. The results of the project activities encompass the analysis and evaluation of various problem areas associated with planning and management of the grid during normal operation and periods of malfunction, as well as required modifications to safety systems and grid configurations. The analyses, based on simulation calculations on specific medium and low voltage grids, are discussed. The results of simulations are discussed that involved grids partly fed by already existing distributed power plants and, additionally, by a varying number of further distributed production units. In addition to an intensive evaluation of the normal grid status, considerations and analyses were carried out concerning isolated operation ('islanding') and transitions from one grid status to another. The findings obtained from these studies are discussed, including effects such as voltage-fluctuation caused by power flow, harmonics caused by inverters and grid resonance effects.

  6. Thermodynamic analysis of the advanced zero emission power plant

    Directory of Open Access Journals (Sweden)

    Kotowicz Janusz

    2016-03-01

    Full Text Available The paper presents the structure and parameters of advanced zero emission power plant (AZEP. This concept is based on the replacement of the combustion chamber in a gas turbine by the membrane reactor. The reactor has three basic functions: (i oxygen separation from the air through the membrane, (ii combustion of the fuel, and (iii heat transfer to heat the oxygen-depleted air. In the discussed unit hot depleted air is expanded in a turbine and further feeds a bottoming steam cycle (BSC through the main heat recovery steam generator (HRSG. Flue gas leaving the membrane reactor feeds the second HRSG. The flue gas consist mainly of CO2 and water vapor, thus, CO2 separation involves only the flue gas drying. Results of the thermodynamic analysis of described power plant are presented.

  7. Power and sample size in cost-effectiveness analysis.

    Science.gov (United States)

    Laska, E M; Meisner, M; Siegel, C

    1999-01-01

    For resource allocation under a constrained budget, optimal decision rules for mutually exclusive programs require that the treatment with the highest incremental cost-effectiveness ratio (ICER) below a willingness-to-pay (WTP) criterion be funded. This is equivalent to determining the treatment with the smallest net health cost. The designer of a cost-effectiveness study needs to select a sample size so that the power to reject the null hypothesis, the equality of the net health costs of two treatments, is high. A recently published formula derived under normal distribution theory overstates sample-size requirements. Using net health costs, the authors present simple methods for power analysis based on conventional normal and on nonparametric statistical theory.

  8. Thermodynamic analysis of the advanced zero emission power plant

    Science.gov (United States)

    Kotowicz, Janusz; Job, Marcin

    2016-03-01

    The paper presents the structure and parameters of advanced zero emission power plant (AZEP). This concept is based on the replacement of the combustion chamber in a gas turbine by the membrane reactor. The reactor has three basic functions: (i) oxygen separation from the air through the membrane, (ii) combustion of the fuel, and (iii) heat transfer to heat the oxygen-depleted air. In the discussed unit hot depleted air is expanded in a turbine and further feeds a bottoming steam cycle (BSC) through the main heat recovery steam generator (HRSG). Flue gas leaving the membrane reactor feeds the second HRSG. The flue gas consist mainly of CO2 and water vapor, thus, CO2 separation involves only the flue gas drying. Results of the thermodynamic analysis of described power plant are presented.

  9. Dynamic Analysis & Characterization of Conventional Hydraulic Power Supply Units

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Liedhegener, Michael; Bech, Michael Møller

    2016-01-01

    Hydraulic power units operated as constant supply pres-sure systems remain to be widely used in the industry, to supply valve controlled hydraulic drives etc., where the hydraulic power units are constituted by variable pumps with mechanical outlet pressure control, driven by induction motors....... In the analysis of supplied drives, both linear and rotary, emphasis is commonly placed on the drives themselves and the related loads, and the supply system dynamics is often given only little attention, and usually neglected or taken into account in a simplified fashion. The simplified supply system dynamics...... such that limited impact on the drive dynamics is observed. Such ideal properties however, are not necessarily present in industrial hydraulic applications for various reasons, with the most common being large volumes of supply lines. Long supply lines, hence large supply line volumes, between the sup-ply system...

  10. Analysis of Control Power in Controlled Remote State Preparation Schemes

    Science.gov (United States)

    Li, Xihan; Ghose, Shohini

    2017-03-01

    We quantify and analyze the controller's power in controlled remote state preparation schemes. Our analysis provides a lower bound on the control power required for controlled remote preparation of arbitrary D-dimensional states. We evaluate several existing controlled remote state preparation protocols and show that some proposed non-maximally entangled channels are not suitable for perfect controlled remote preparation of arbitrary quantum states from the controller's point of view. We find that for remotely preparing D-dimensional states, the entropy of each controller should be no less than log2 D bits. Our new criteria are not only useful for evaluating controlled remote state preparation schemes but can also be used for other controlled quantum communication schemes.

  11. Power consumption analysis of operating systems for wireless sensor networks.

    Science.gov (United States)

    Lajara, Rafael; Pelegrí-Sebastiá, José; Perez Solano, Juan J

    2010-01-01

    In this paper four wireless sensor network operating systems are compared in terms of power consumption. The analysis takes into account the most common operating systems--TinyOS v1.0, TinyOS v2.0, Mantis and Contiki--running on Tmote Sky and MICAz devices. With the objective of ensuring a fair evaluation, a benchmark composed of four applications has been developed, covering the most typical tasks that a Wireless Sensor Network performs. The results show the instant and average current consumption of the devices during the execution of these applications. The experimental measurements provide a good insight into the power mode in which the device components are running at every moment, and they can be used to compare the performance of different operating systems executing the same tasks.

  12. Principal Component Analysis - A Powerful Tool in Computing Marketing Information

    Directory of Open Access Journals (Sweden)

    Constantin C.

    2014-12-01

    Full Text Available This paper is about an instrumental research regarding a powerful multivariate data analysis method which can be used by the researchers in order to obtain valuable information for decision makers that need to solve the marketing problem a company face with. The literature stresses the need to avoid the multicollinearity phenomenon in multivariate analysis and the features of Principal Component Analysis (PCA in reducing the number of variables that could be correlated with each other to a small number of principal components that are uncorrelated. In this respect, the paper presents step-by-step the process of applying the PCA in marketing research when we use a large number of variables that naturally are collinear.

  13. Analysis in environmental radioactivity around Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

    2003-12-15

    Twelve kinds of environmental samples such as soil, seawater, underground water, etc. around Nuclear Power Plants(NPPs) were collected. Tritium chemical analysis was tried for the samples of rain water, pine-needle, air, seawater, underground water, chinese cabbage, again of rice and milk sampled around NPPs, and surface seawater and rain water sampled over the country. Strontium in the soil that were sampled at 60 point of district in Korea were analyzed. Tritium were analyzed in 21 samples of surface seawater around the Korea peninsular that were supplied form KFRDI(National Fisheries Research and Development Institute). Sampling and chemical analysis environmental samples around Kori, Woolsung, Youngkwang, Wooljin NPPs and Taeduk science town for tritium and strontium analysis was managed according to plans. Succeed to KINS after all samples were tried.

  14. Heat transfer analysis in an annular cone subjected to power law variations

    Science.gov (United States)

    Salman Ahmed, N. J.; Al-Rashed, Abdullah A. A. A.; Yunus Khan, T. M.; Kamangar, Sarfaraz; Athani, Abdulgaphur; Anjum Badruddin, Irfan

    2016-09-01

    Present study deals with the analysis of heat transfer and fluid flow behavior in an annular cone fixed with saturated porous medium. The inner surface of the cone is assumed to have power law variable wall temperature. The governing partial differential equations are solved using well known Finite Element Method (FEM). The coupled nonlinear differential equations are converted into the algebraic equations by using Galerkin method. A 3 noded triangular element is used to divide the porous domain into smaller segments. The effects of various geometrical parameters on the cone angle are presented. It is found that the effect of cone angle on the heat transfer characteristics and fluid flow behavior is considerably significant. The fluid moment is found to shift towards the upper side of cone with increase in the power law coefficient. The fluid velocity decreases with increase in the power law coefficient.

  15. The Analysis of SBWR Critical Power Bundle Using Cobrag Code

    Directory of Open Access Journals (Sweden)

    Yohannes Sardjono

    2013-03-01

    Full Text Available The coolant mechanism of SBWR is similar with the Dodewaard Nuclear Power Plant (NPP in the Netherlands that first went critical in 1968. The similarity of both NPP is cooled by natural convection system. These coolant concept is very related with same parameters on fuel bundle design especially fuel bundle length, core pressure drop and core flow rate as well as critical power bundle. The analysis was carried out by using COBRAG computer code. COBRAG computer code is GE Company proprietary. Basically COBRAG computer code is a tool to solve compressible three-dimensional, two fluid, three field equations for two phase flow. The three fields are the vapor field, the continuous liquid field, and the liquid drop field. This code has been applied to analyses model flow and heat transfer within the reactor core. This volume describes the finitevolume equations and the numerical solution methods used to solve these equations. This analysis of same parameters has been done i.e.; inlet sub cooling 20 BTU/lbm and 40 BTU/lbm, 1000 psi pressure and R-factor is 1.038, mass flux are 0.5 Mlb/hr.ft2, 0.75 Mlb/hr.ft2, 1.00 Mlb/hr.ft2 and 1.25 Mlb/hr.ft2. Those conditions based on history operation of some type of the cell fuel bundle line at GE Nuclear Energy. According to the results, it can be concluded that SBWR critical power bundle is 10.5 % less than current BWR critical power bundle with length reduction of 12 ft to 9 ft.

  16. Thermoeconomic Analysis of Advanced Solar-Fossil Combined Power Plants

    Directory of Open Access Journals (Sweden)

    Yassine Allani

    2000-12-01

    Full Text Available

    Hybrid solar thermal power plants (with parabolic trough type of solar collectors featuring gas burners and Rankine steam cycles have been successfully demonstrated by California's Solar Electric Generating System (SEGS. This system has been proven to be one of the most efficient and economical schemes to convert solar energy into electricity. Recent technological progress opens interesting prospects for advanced cycle concepts: a the ISCCS (Integrated Solar Combined Cycle System that integrates the parabolic trough into a fossil fired combined cycle, which allows a larger exergy potential of the fuel to be converted. b the HSTS (Hybrid Solar Tower System which uses high concentration optics (via a power tower generator and high temperature air receivers to drive the combined cycle power plant. In the latter case, solar energy is used at a higher exergy level as a heat source of the topping cycle. This paper presents the results of a thermoeconomic investigation of an ISCCS envisaged in Tunisia. The study is realized in two phases. In the first phase, a mixed approach, based on pinch technology principles coupled with a mathematical optimization algorithm, is used to minimize the heat transfer exergy losses in the steam generators, respecting the off design operating conditions of the steam turbine (cone law. In the second phase, an economic analysis based on the Levelized Electricity Cost (LEC approach was carried out for the configurations, which provided the best concepts during the first phase. A comparison of ISCCS with pure fossil fueled plants (CC+GT is reported for the same electrical power load. A sensitivity analysis based on the relative size of the solar field is presented.

    •  This paper was presented at the ECOS'00 Conference in Enschede, July 5-7, 2000

  17. 福清核电1、2号机组增大应急给水箱容积安全分析%Safety Analysis on the Volume Increase of Auxiliary Water Tank for Number One and Two Units of Fuqing Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    佟立丽; 邵舸; 顾健; 薛峻峰; 彭建平; 王志强

    2013-01-01

    When main feed water system or start-up feed water system is unavailable, auxiliary feed water system, as Engineered Safety Facility (ESF), provides water for Steam Generators (SG) to remove the stored and decay heat from the reactor core. In order to improve the safety of Nuclear Power Plants (NPPs) and increase operational flexibility, the water inventory of the auxiliary feed water tank is increased in the number one and two units of Fuqing NPP. The model of the NPP is built based on mechanical safety analytical code, and conservative assumptions are used in the calculation. Three typical accident sequences, such as loss of main feed water, loss of offsite power in category Ⅱ accident, and main feed water line break in category IV, are selected to analyze whether or not the inventory in auxiliary water tank after improvement satisfies the relevant requirements in RCC-R The results show that auxiliary water inventory of 713m3 is needed for loss of main feed water accident, auxiliary water inventory of 723m3 is needed for loss of offsite power accident, and auxiliary water inventory of 799m3 is needed for main feed water line break accident. The inventory in auxiliary water tank after improvement satisfies the requirements for category Ⅱ and Ⅳ accidents. The safety of NPP is improved due to the inventory redundancy and a time window is also provided for the operators to perform related accident procedures.%辅助给水系统(ASG)作为专设安全设施在主给水或启动给水不可用时向蒸汽发生器供水,以导出堆芯余热.为了提高电厂安全性,增加运行灵活性,福清核电1、2号机组对应急给水箱的有效容积进行了增加.本文采用机理性安全分析程序,建立核电厂分析模型,在计算过程中采用保守假设条件,选取Ⅱ类工况下正常给水丧失事故,厂外电丧失事故,Ⅳ类工况下主给水管道破裂事故3条典型事故序列,分析改进后的应急给水箱容量是否满足压水

  18. Analysis of Highly Wind Power Integrated Power System model performance during Critical Weather conditions

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2014-01-01

    . For this purpose, the power system model has been developed that represents the relevant dynamic features of power plants and compensates for power imbalances caused by the forecasting error during critical weather conditions. The regulating power plan, as an input time series for the developed power system model......Secure power system operation of a highly wind power integrated power system is always at risk during critical weather conditions, e.g. in extreme high winds. The risk is even higher when 50% of the total electricity consumption has to be supplied by wind power, as the case for the future Danish...... power system in 2020. This paper analyses and compares the performance of the future Danish power system during extreme wind speeds, where wind power plants are either controlled through a traditional High Wind Shut Down storm controller or a new High Wind Extended Production storm controller...

  19. Increasing the Discriminatory Power of DEA Using Shannon’s Entropy

    Directory of Open Access Journals (Sweden)

    Qiwei Xie

    2014-03-01

    Full Text Available In many data envelopment analysis (DEA applications, the analyst always confronts the difficulty that the selected data set is not suitable to apply traditional DEA models for their poor discrimination. This paper presents an approach using Shannon’s entropy to improve the discrimination of traditional DEA models. In this approach, DEA efficiencies are first calculated for all possible variable subsets and analyzed using Shannon’s entropy theory to calculate the degree of the importance of each subset in the performance measurement, then we combine the obtained efficiencies and the degrees of importance to generate a comprehensive efficiency score (CES, which can observably improve the discrimination of traditional DEA models. Finally, the proposed approach has been applied to some data sets from the prior DEA literature.

  20. Strongly increasing solutions of cyclic systems of second order differential equations with power-type nonlinearities

    Directory of Open Access Journals (Sweden)

    Jaroslav Jaroš

    2015-01-01

    Full Text Available We consider \\(n\\-dimensional cyclic systems of second order differential equations \\[(p_i(t|x_{i}'|^{\\alpha_i -1}x_{i}'' = q_{i}(t|x_{i+1}|^{\\beta_i-1}x_{i+1},\\] \\[\\quad i = 1,\\ldots,n, \\quad (x_{n+1} = x_1 \\tag{\\(\\ast\\}\\] under the assumption that the positive constants \\(\\alpha_i\\ and \\(\\beta_i\\ satisfy \\(\\alpha_1{\\ldots}\\alpha_n \\gt \\beta_1{\\ldots}\\beta_n\\ and \\(p_i(t\\ and \\(q_i(t\\ are regularly varying functions, and analyze positive strongly increasing solutions of system (\\(\\ast\\ in the framework of regular variation. We show that the situation for the existence of regularly varying solutions of positive indices for (\\(\\ast\\ can be characterized completely, and moreover that the asymptotic behavior of such solutions is governed by the unique formula describing their order of growth precisely. We give examples demonstrating that the main results for (\\(\\ast\\ can be applied to some classes of partial differential equations with radial symmetry to acquire accurate information about the existence and the asymptotic behavior of their radial positive strongly increasing solutions.

  1. Exergy Analysis of Operating Lignite Fired Thermal Power Plant

    Directory of Open Access Journals (Sweden)

    K. Murugesan

    2009-01-01

    Full Text Available The energy assessment must be made through the energy quantity as well as the quality. But the usual energy analysisevaluates the energy generally on its quantity only. However, the exergy analysis assesses the energy on quantity as well asthe quality. The aim of the exergy analysis is to identify the magnitudes and the locations of real energy losses, in order toimprove the existing systems, processes or components. The present paper deals with an exergy analysis performed on anoperating 50MWe unit of lignite fired steam power plant at Thermal Power Station-I, Neyveli Lignite Corporation Limited,Neyveli, Tamil Nadu, India. The exergy losses occurred in the various subsystems of the plant and their components havebeen calculated using the mass, energy and exergy balance equations. The distribution of the exergy losses in several plantcomponents during the real time plant running conditions has been assessed to locate the process irreversibility. The Firstlaw efficiency (energy efficiency and the Second law efficiency (exergy efficiency of the plant have also been calculated.The comparison between the energy losses and the exergy losses of the individual components of the plant shows that themaximum energy losses of 39% occur in the condenser, whereas the maximum exergy losses of 42.73% occur in the combustor.The real losses of energy which has a scope for the improvement are given as maximum exergy losses that occurredin the combustor.

  2. Availability Analysis of Gas Turbines Used in Power Plants

    Directory of Open Access Journals (Sweden)

    Gilberto Francisco Martha de Souza

    2009-03-01

    Full Text Available The availability of a complex system, such as a gas turbine, is strongly associated with its parts reliability and maintenance policy. That policy not only has influence on the parts’ repair time but also on the parts’ reliability affecting the system degradation and availability. This study presents a method for reliability and availability evaluation of gas turbines installed in an electric power station. The method is based on system reliability concepts, such as functional tree development, application of failure mode and effects analysis to identify critical components for improvement of system reliability, and reliability and maintainability evaluation based on a historical failure database. The method also proposes the application of Reliability Centered Maintenance concepts to improve complex system maintenance policies aimed at the reduction of unexpected failure occurrences in critical components. The method is applied to the analysis of two F series gas turbines, each with an output of 150 MW, installed in a 500 MW combined cycle power plant. The reliability and availability of the turbines are simulated based on a five-year failure database. The availability analysis shows different results for each turbine, one presenting 99% and the other 96% availability, indicating differences in their systems installation and operation.

  3. Sandia-Power Surety Task Force Hawaii foam analysis.

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Annie

    2010-11-01

    The Office of Secretary of Defense (OSD) Power Surety Task Force was officially created in early 2008, after nearly two years of work in demand reduction and renewable energy technologies to support the Warfighter in Theater. The OSD Power Surety Task Force is tasked with identifying efficient energy solutions that support mission requirements. Spray foam insulation demonstrations were recently expanded beyond field structures to include military housing at Ft. Belvoir. Initial results to using the foam in both applications are favorable. This project will address the remaining key questions: (1) Can this technology help to reduce utility costs for the Installation Commander? (2) Is the foam cost effective? (3) What application differences in housing affect those key metrics? The critical need for energy solutions in Hawaii and the existing relationships among Sandia, the Department of Defense (DOD), the Department of Energy (DOE), and Forest City, make this location a logical choice for a foam demonstration. This project includes application and analysis of foam to a residential duplex at the Waikulu military community on Oahu, Hawaii, as well as reference to spray foam applied to a PACOM facility and additional foamed units on Maui, conducted during this project phase. This report concludes the analysis and describes the utilization of foam insulation at military housing in Hawaii and the subsequent data gathering and analysis.

  4. Second law analysis of a conventional steam power plant

    Science.gov (United States)

    Liu, Geng; Turner, Robert H.; Cengel, Yunus A.

    1993-01-01

    A numerical investigation of exergy destroyed by operation of a conventional steam power plant is computed via an exergy cascade. An order of magnitude analysis shows that exergy destruction is dominated by combustion and heat transfer across temperature differences inside the boiler, and conversion of energy entering the turbine/generator sets from thermal to electrical. Combustion and heat transfer inside the boiler accounts for 53.83 percent of the total exergy destruction. Converting thermal energy into electrical energy is responsible for 41.34 percent of the total exergy destruction. Heat transfer across the condenser accounts for 2.89 percent of the total exergy destruction. Fluid flow with friction is responsible for 0.50 percent of the total exergy destruction. The boiler feed pump turbine accounts for 0.25 percent of the total exergy destruction. Fluid flow mixing is responsible for 0.23 percent of the total exergy destruction. Other equipment including gland steam condenser, drain cooler, deaerator and heat exchangers are, in the aggregate, responsible for less than one percent of the total exergy destruction. An energy analysis is also given for comparison of exergy cascade to energy cascade. Efficiencies based on both the first law and second law of thermodynamics are calculated for a number of components and for the plant. The results show that high first law efficiency does not mean high second law efficiency. Therefore, the second law analysis has been proven to be a more powerful tool in pinpointing real losses. The procedure used to determine total exergy destruction and second law efficiency can be used in a conceptual design and parametric study to evaluate the performance of other steam power plants and other thermal systems.

  5. Activated region fitting: a robust high-power method for fMRI analysis using parameterized regions of activation.

    Science.gov (United States)

    Weeda, Wouter D; Waldorp, Lourens J; Christoffels, Ingrid; Huizenga, Hilde M

    2009-08-01

    An important issue in the analysis of fMRI is how to account for the spatial smoothness of activated regions. In this article a method is proposed to accomplish this by modeling activated regions with Gaussian shapes. Hypothesis tests on the location, spatial extent, and amplitude of these regions are performed instead of hypothesis tests of individual voxels. This increases power and eases interpretation. Simulation studies show robust hypothesis tests under misspecification of the shape model, and increased power over standard techniques especially at low signal-to-noise ratios. An application to real single-subject data also indicates that the method has increased power over standard methods.

  6. Development of RCM analysis software for Korean nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Ho; Choi, Kwang Hee; Jeong, Hyeong Jong [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A software called KEPCO RCM workstation (KRCM) has been developed to optimize the maintenance strategies of Korean nuclear power plants. The program modules of the KRCM were designed in a manner that combines EPRI methodologies and KEPRI analysis technique. The KRCM is being applied to the three pilot system, chemical and volume control system, main steam system, and compressed air system of Yonggwang Units 1 and 2. In addition, the KRCM can be utilized as a tool to meet a part of the requirements of maintenance rule (MR) imposed by U.S. NRC. 3 refs., 4 figs. (Author)

  7. Beam instability in 980-nm power lasers: Experiment and analysis

    Science.gov (United States)

    Guthrie, James; Tan, G. L.; Ohkubo, M.; Fukushima, T.; Ikegami, Y.; Ijichi, T.; Irikawa, M.; Mand, R. S.; Xu, J. M.

    1994-12-01

    A theoretical analysis of beam instability (steering), commonly observed in high power ridge waveguide laser diodes is presented. A physical model of multiple interfering lateral modes is proposed and implemented in a two-dimensional self-consistent numerical code. It is shown that the dynamic evolution of the effective waveguide and the coherent lasing of emergent multiple lateral modes of the waveguide under high injection could lead to beam steering and knees in the fiber coupled L-I characteristics. The theory of simultaneous lasing and interaction between several lateral modes is found to be consistent with the observed back-plane radiation image.

  8. A novel electric power quality monitoring system for transient analysis

    OpenAIRE

    2014-01-01

    Electricity is vital for our daily life in modern cites. In order to ensure its reliability and supply, an electric power monitoring system is indispensable in an electric power system. Currently, most electric power monitoring systems are designed for steady-state monitoring only. They may not be able to monitor instantaneous power disturbances, such as voltage surge, happened in electric power systems. In fact, instantaneous power disturbances are frequently found in electric power systems,...

  9. The Power of Three: Coral Reefs, Seagrasses and Mangroves Protect Coastal Regions and Increase Their Resilience.

    Science.gov (United States)

    Guannel, Greg; Arkema, Katie; Ruggiero, Peter; Verutes, Gregory

    2016-01-01

    Natural habitats have the ability to protect coastal communities against the impacts of waves and storms, yet it is unclear how different habitats complement each other to reduce those impacts. Here, we investigate the individual and combined coastal protection services supplied by live corals on reefs, seagrass meadows, and mangrove forests during both non-storm and storm conditions, and under present and future sea-level conditions. Using idealized profiles of fringing and barrier reefs, we quantify the services supplied by these habitats using various metrics of inundation and erosion. We find that, together, live corals, seagrasses, and mangroves supply more protection services than any individual habitat or any combination of two habitats. Specifically, we find that, while mangroves are the most effective at protecting the coast under non-storm and storm conditions, live corals and seagrasses also moderate the impact of waves and storms, thereby further reducing the vulnerability of coastal regions. Also, in addition to structural differences, the amount of service supplied by habitats in our analysis is highly dependent on the geomorphic setting, habitat location and forcing conditions: live corals in the fringing reef profile supply more protection services than seagrasses; seagrasses in the barrier reef profile supply more protection services than live corals; and seagrasses, in our simulations, can even compensate for the long-term degradation of the barrier reef. Results of this study demonstrate the importance of taking integrated and place-based approaches when quantifying and managing for the coastal protection services supplied by ecosystems.

  10. Regression and kriging analysis for grid power factor estimation

    Directory of Open Access Journals (Sweden)

    Rajesh Guntaka

    2014-12-01

    Full Text Available The measurement of power factor (PF in electrical utility grids is a mainstay of load balancing and is also a critical element of transmission and distribution efficiency. The measurement of PF dates back to the earliest periods of electrical power distribution to public grids. In the wide-area distribution grid, measurement of current waveforms is trivial and may be accomplished at any point in the grid using a current tap transformer. However, voltage measurement requires reference to ground and so is more problematic and measurements are normally constrained to points that have ready and easy access to a ground source. We present two mathematical analysis methods based on kriging and linear least square estimation (LLSE (regression to derive PF at nodes with unknown voltages that are within a perimeter of sample nodes with ground reference across a selected power grid. Our results indicate an error average of 1.884% that is within acceptable tolerances for PF measurements that are used in load balancing tasks.

  11. Increasing the energy conservation awareness using the influential power of a lottery system

    Science.gov (United States)

    Nayak, Amruta Vijay

    This thesis presents an influence maximization-driven approach to promoting energy conservation awareness, with the objective to generate a competitive environment for energy consumption supervision. As consumers are typically reluctant to invest their time and effort in the activities beyond their business, an incentive-based distribution strategy is proposed to encourage consumers to actively take part in energy conservation. The key idea of the thesis lies in leveraging the consumer instincts as a driving factor for spreading positive social influence, via a smart lottery program. In the proposed framework, saving energy automatically increases the consumers' chances of winning the lottery, thereby motivating them to save more, while the smart winner selection will maximize the word-of-mouth effect of the program. The thesis collects and organizes a large body of literature in support of the claim that the spread of awareness in a social network can play a key role in the emergence of energy conscious behavior. It also reports on the findings of a survey conducted to determine the present day consumer perspective toward energy conservation and the level of influence required to motivate them to conserve more energy. Finally, a mathematical model for smart lottery winner selection is presented, and insightful observations are made concerning the properties of optimal solutions to tractable, small problem instances.

  12. The Increasing of Air and Biogas Mixer Instrument for Generating Friendly Environmental Electricity Power

    Science.gov (United States)

    Ketut Lasmi, Ni; Singarimbun, Alamta; Srigutomo, Wahyu

    2016-08-01

    The abolition of BBM Subsidize by the government causes increasing of its price, so a solution is necessary to find an alternative energy that is relatively cheap, environmentally friendly and affordable by all layers of society. Biogas is one of the renewable energy resources that are potential to be developed, especially in a farming area, because up until now, animal's excrement is not yet optimally used and it causes problem to environment. In response to this, one innovation to do is to make an instrument which is able to mix biogas and air by venture pipe using the basic theory of fluid mechanic, in order to raise the use of biogas as electricity source. Biogas conversion is done by changing fuel in benzene 5 kilowatt genset to biogas so it becomes a biogas genset. The biogas pressure is controlled when it enters the mixer instrument so that the velocity of biogas when it enters and it comes out the mixer is the same, and it will gain different pressure between biogas and air. By the pressure difference between biogas in the mixer instrument, biogas goes to the burning room so that the conversion of mechanical energy biogas to electricity will happen, and it will be applied as light and society's needs.

  13. Are Public-Private Partnerships an Appropriate Governance Structure for Power Plants? A Transaction Cost Analysis

    Science.gov (United States)

    Ho, S. Ping; Hsu, Yaowen

    2015-04-01

    In order to meet the requirements of the rapid economic growth, many countries demand an increasing number of power plants to meet the increasing electricity usage. Since high capital requirements of power plants present a big issue for these countries, PPPs have been considered an alternative to provide power plant infrastructure. In particular, in emerging or developing countries, PPPs may be the fastest way to provide the infrastructure needed. However, while PPPs are a promising alternative to providing various types of infrastructure, many failed power plant PPP projects have made it evident that PPPs, under certain situations, can be very costly or even a wrong choice of governance structure. While the higher efficiency due to better pooling of resources is greatly emphasized in Public-Private Partnerships (PPPs), the embedded transaction inefficiencies are often understated or even ignored. Through the lens of Transaction Cost Economics (TCE), this paper aims to answer why and when PPPs may become a costly governance structure for power plants. Specifically, we develop a TCE-based theory of PPPs as a governance structure. This theory suggests that three major opportunism problems embedded in infrastructure PPPs are possible to cause substantial transaction costs and render PPPs a costly governance structure. The three main opportunism problems are principal-principal problem, firm's hold-up problem, and government-led hold-up problem. Moreover, project and institutional characteristics that may lead to opportunism problems are identified. Based on these characteristics, an opportunism-focused transaction cost analysis (OTCA) for PPPs as a governance structure is proposed to supplement the current practice of PPP feasibility analysis. As a part of theory development, a case study of PPP power plants is performed to evaluate the proposed theory and to illustrate how the proposed OTCA can be applied in practice. Policies and administration strategies for power

  14. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

    In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...

  15. An analysis of increasing price of gricultural products

    Institute of Scientific and Technical Information of China (English)

    王豪; 周婷婷

    2008-01-01

    @@ This report consists of following sections:at first,this report will show the content and source of the cited article,the topic of which is that price hikes for meat,eggs to affect CPI in china;Second,this part mostly presents some theories of economics which are related to the price;Third,through economic analysis,this part search for the method that solve the problem;At last,we will get the conclusion.

  16. Analysis of a carbon dioxide transcritical power cycle using a low temperature source

    Energy Technology Data Exchange (ETDEWEB)

    Cayer, Emmanuel; Galanis, Nicolas; Desilets, Martin; Roy, Philippe [Universite de Sherbrooke, Genie mecanique, Sherbrooke, QC (Canada); Nesreddine, Hakim [LTE-Hydro-Quebec, 600 Av. de la Montagne, Shawinigan, QC (Canada)

    2009-07-15

    A detailed analysis of a carbon dioxide transcritical power cycle using an industrial low-grade stream of process gases as its heat source is presented. The methodology is divided in four steps: energy analysis, exergy analysis, finite size thermodynamics and calculation of the heat exchangers' surface. The results have been calculated for fixed temperature and mass flow rate of the heat source, fixed maximum and minimum temperatures in the cycle and a fixed sink temperature by varying the high pressure of the cycle and its net power output. The main results show the existence of an optimum high pressure for each of the four steps; in the first two steps, the optimum pressure maximises the thermal or exergetic efficiency while in the last two steps it minimises the product UA or the heat exchangers' surface. These high pressures are very similar for the energy and exergy analyses. The last two steps also have nearly identical optimizing high pressures that are significantly lower that the ones for the first two steps. In addition, the results show that the augmentation of the net power output produced from the limited energy source has no influence on the results of the energy analysis, decreases the exergetic efficiency and increases the heat exchangers' surface. Changing the net power output has no significant impact on the high pressures optimizing each of the four steps. (author)

  17. Power Analysis in Survey Research: Importance and Use for Health Educators

    Science.gov (United States)

    Price, James H.; Dake, Joseph A.; Murnan, Judy; Dimmig, Jaime; Akpanudo, Sutoidem

    2005-01-01

    This article has three purposes: to explain the two different uses of power analysis that can be used in health education research; to examine the extent to which power analysis is being used in published health education research; and to explain the implications of not using power analysis in research studies. Articles in seven leading health…

  18. Modeling and analysis of harmonic resonance in a power electronics based AC power system

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Chen, Zhe

    2013-01-01

    The dynamic interactions among the interconnected power converters may bring in harmonic resonance in a power electronics based power system. This paper addresses this issue in a power system dominated by multiple current- and voltage-controlled inverters with LCL- and LC-filters. The impedance-b...

  19. Analysis and Review on Development of Power Sources in 2006

    Institute of Scientific and Technical Information of China (English)

    Wang Nan

    2007-01-01

    @@ Influenced by the rapid growing of power demand in recent years, power sources construction has been expanded fleetly in China. This article reviews the features of power sources development nationwide in 2006 and the problems that still existed in the structure of power sources. Finally,suggestions on further developing power sources are proposed.

  20. GNSS Spoofing Detection Based on Signal Power Measurements: Statistical Analysis

    Directory of Open Access Journals (Sweden)

    V. Dehghanian

    2012-01-01

    Full Text Available A threat to GNSS receivers is posed by a spoofing transmitter that emulates authentic signals but with randomized code phase and Doppler values over a small range. Such spoofing signals can result in large navigational solution errors that are passed onto the unsuspecting user with potentially dire consequences. An effective spoofing detection technique is developed in this paper, based on signal power measurements and that can be readily applied to present consumer grade GNSS receivers with minimal firmware changes. An extensive statistical analysis is carried out based on formulating a multihypothesis detection problem. Expressions are developed to devise a set of thresholds required for signal detection and identification. The detection processing methods developed are further manipulated to exploit incidental antenna motion arising from user interaction with a GNSS handheld receiver to further enhance the detection performance of the proposed algorithm. The statistical analysis supports the effectiveness of the proposed spoofing detection technique under various multipath conditions.

  1. TREEFINDER: a powerful graphical analysis environment for molecular phylogenetics

    Directory of Open Access Journals (Sweden)

    von Haeseler Arndt

    2004-06-01

    Full Text Available Abstract Background Most analysis programs for inferring molecular phylogenies are difficult to use, in particular for researchers with little programming experience. Results TREEFINDER is an easy-to-use integrative platform-independent analysis environment for molecular phylogenetics. In this paper the main features of TREEFINDER (version of April 2004 are described. TREEFINDER is written in ANSI C and Java and implements powerful statistical approaches for inferring gene tree and related analyzes. In addition, it provides a user-friendly graphical interface and a phylogenetic programming language. Conclusions TREEFINDER is a versatile framework for analyzing phylogenetic data across different platforms that is suited both for exploratory as well as advanced studies.

  2. Study and Analysis of a Natural Reference Frame Current Controller for a Multi-Level H-Bridge Power Converter

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Iov, Florin; Zanchetta, P.;

    2008-01-01

    will be needed in order to control the power flow and to ensure proper and secure operation of this future grid with an increased level of renewable power. These power converters must be able to provide intelligent power management as well as ancillary services. This paper presents an analysis of the natural...... reference frame controller, based on proportional-resonant (PR) technique, for a multi-level H-bridge power converter for Universal and Flexible Power Management in Future Electricity Network. The proposed method is tested in terms of harmonic content in the Point of Common Coupling (PCC), voltage......To pave the way to a sustainable energy future based on a larger share of Distributed Generation (DG), there is a clear need to prepare the European electricity system for the large-scale integration of both renewable and other distributed energy sources. Advanced power electronic converters for DG...

  3. Analysis of three-phase power transformer laminated magnetic core designs

    Directory of Open Access Journals (Sweden)

    M.I. Levin

    2014-03-01

    Full Text Available Analysis and research into properties and parameters of different-type laminated magnetic cores of three-phase power transformers are conducted. Most of new laminated magnetic core designs are found to have significant shortcomings resulted from design and technological features of their manufacturing. These shortcomings cause increase in ohmic loss in the magnetic core, which eliminates advantages of the new core configurations and makes them uncompetitive as compared with the classical laminated magnetic core design.

  4. Analysis and Simulation of Fault Characteristics of Power Switch Failures in Distribution Electronic Power Transformers

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2013-08-01

    Full Text Available This paper presents research on the voltage and current distortion in the input stage, isolation stage and output stage of Distribution Electronic Power transformer (D-EPT after the open-circuit and short-circuit faults of its power switches. In this paper, the operational principles and the control methods for input stage, isolation stage and output stage of D-EPT, which work as a cascaded H-bridge rectifier, DC-DC converter and inverter, respectively, are introduced. Based on conclusions derived from the performance analysis of D-EPT after the faults, this paper comes up with the effects from its topology design and control scheme on the current and voltage distortion. According to the EPT fault characteristics, since the waveforms of relevant components heavily depend on the location of the faulty switch, it is very easy to locate the exact position of the faulty switch. Finally, the fault characteristics peculiar to D-EPT are analyzed, and further discussed with simulation on the Saber platform, as well as a fault location diagnosis algorithm.

  5. Analysis of Contradiction Between Cool and Power Industry

    Institute of Scientific and Technical Information of China (English)

    Huang Shaozhong

    2008-01-01

    @@ At the beginning of 2008,the Central,East and South China suffered a rare snow and ice disaster.After the disaster,power generation and power grid enterprises faced a big problem of power coal supply.

  6. Potential Analysis of Regulating Power from Electric Vehicle (EV) Integration in Denmark

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Nielsen, Arne Hejde; Østergaard, Jacob

    2011-01-01

    The potential analysis of having electric vehicles (EVs) provide regulating power has been implemented. The possible regulating power capacity from EVs and the economic return for EV users by providing regulating power are obtained. A spot price based charging schedule scenario has been used to do....... The activated regulating power and regulating power prices in the Denmark West System in 2010 have been used to calculate the economic return for EV users if all the regulating power is provided by EVs....

  7. Analysis of Loss-of-Offsite-Power Events 1998–2013

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-02-01

    Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. Risk analyses suggest that loss of all alternating current power contributes over 70% of the overall risk at some U.S. nuclear plants. LOOP event and subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience during calendar years 1997 through 2013. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. The emergency diesel generator failure modes considered are failure to start, failure to load and run, and failure to run more than 1 hour. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. No statistically significant trends in LOOP frequencies over the 1997–2013 period are identified. There is a possibility that a significant trend in grid-related LOOP frequency exists that is not easily detected by a simple analysis. Statistically significant increases in recovery times after grid- and switchyard-related LOOPs are identified.

  8. Increasing the performance of tritium analysis by electrolytic enrichment.

    Science.gov (United States)

    Groning, M; Auer, R; Brummer, D; Jaklitsch, M; Sambandam, C; Tanweer, A; Tatzber, H

    2009-06-01

    Several improvements are described for the existing tritium enrichment system at the Isotope Hydrology Laboratory of the International Atomic Energy Agency for processing natural water samples. The improvements include a simple method for pretreatment of electrolytic cells to ensure a high tritium separation factor, an improved design of the exhaust system for explosive gases, and a vacuum distillation line for faster initial preparation of water samples for electrolytic enrichment and for tritium analysis. Achievements included the reduction of variation of individual enrichment parameters of all cells to less than 1% and an improvement of 50% of the stability of the background mean. It resulted in an improved detection limit of less than 0.4 TU (at 2s), important for application of tritium measurements in the future at low concentration levels, and resulted in measurement precisions of+/-0.2 TU and+/-0.15 TU for liquid scintillation counting and for gas proportional counting, respectively.

  9. Analysis of Nigeria research reactor-1 thermal power calibration methods

    Energy Technology Data Exchange (ETDEWEB)

    Agbo, Sunday Arome; Ahmed, Yusuf Aminu; Ewa, Ita Okon; Jibrin, Yahaya [Ahmadu Bello University, Zaria (Nigeria)

    2016-06-15

    This paper analyzes the accuracy of the methods used in calibrating the thermal power of Nigeria Research Reactor-1 (NIRR-1), a low-power miniature neutron source reactor located at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. The calibration was performed at three different power levels: low power (3.6 kW), half power (15 kW), and full power (30 kW). Two methods were used in the calibration, namely, slope and heat balance methods. The thermal power obtained by the heat balance method at low power, half power, and full power was 3.7 ± 0.2 kW, 15.2 ± 1.2 kW, and 30.7 ± 2.5 kW, respectively. The thermal power obtained by the slope method at half power and full power was 15.8 ± 0.7 kW and 30.2 ± 1.5 kW, respectively. It was observed that the slope method is more accurate with deviations of 4% and 5% for calibrations at half and full power, respectively, although the linear fit (slope method) on average temperature-rising rates during the thermal power calibration procedure at low power (3.6 kW) is not fitting. As such, the slope method of power calibration is not suitable at lower power for NIRR-1.

  10. Performance analysis of monary and binary geothermal power plants operation for Ukraine conditions

    Directory of Open Access Journals (Sweden)

    Аlla Е. Denysova

    2015-03-01

    Full Text Available Every day the shortage in natural gas and coal does increase. In this respect, a great attention is paid to alternative energy sources, and geothermal electrical power generation represents one of the most cost-effective technologies. New power generation technologies using geothermal resources are ecologically clean and are close approaching to traditional ones from the efficiency point of view. This research aim is to analyze the efficiency of monary and binary geothermal power plants operation under actual conditions in Ukraine. Authors discuss prospects for the geothermal power engineering development in Ukraine and other countries. The principal thermal diagrams of monary and binary power plants are represented, as well as their operational principle considering these schemes advantages and disadvantages. Effected is an analysis of such stations performances under conditions of Ukraine. This research value and practical significance are related to the fact that for Ukraine both monary and binary geothermal power plants are very promising, but each engineering solutions should strictly follow its specific functional conditions.

  11. Advanced Thermodynamic Analysis and Evaluation of a Supercritical Power Plant

    Directory of Open Access Journals (Sweden)

    George Tsatsaronis

    2012-06-01

    Full Text Available A conventional exergy analysis can highlight the main components having high thermodynamic inefficiencies, but cannot consider the interactions among components or the true potential for the improvement of each component. By splitting the exergy destruction into endogenous/exogenous and avoidable/unavoidable parts, the advanced exergy analysis is capable of providing additional information to conventional exergy analysis for improving the design and operation of energy conversion systems. This paper presents the application of both a conventional and an advanced exergy analysis to a supercritical coal-fired power plant. The results show that the ratio of exogenous exergy destruction differs quite a lot from component to component. In general, almost 90% of the total exergy destruction within turbines comes from their endogenous parts, while that of feedwater preheaters contributes more or less 70% to their total exergy destruction. Moreover, the boiler subsystem is proven to have a large amount of exergy destruction caused by the irreversibilities within the remaining components of the overall system. It is also found that the boiler subsystem still has the largest avoidable exergy destruction; however, the enhancement efforts should focus not only on its inherent irreversibilities but also on the inefficiencies within the remaining components. A large part of the avoidable exergy destruction within feedwater preheaters is exogenous; while that of the remaining components is mostly endogenous indicating that the improvements mainly depend on advances in design and operation of the component itself.

  12. An Analysis of the Accuracy of Electromechanical Eigenvalue Calculations Based on Instantaneous Power Waveforms Recorded in a Power Plant

    Directory of Open Access Journals (Sweden)

    Piotr Pruski

    2013-12-01

    Full Text Available The paper presents the results of calculating the eigenvalues (associated with electromechanical phenomena of the state matrix of the Polish Power System model on the basis of analysis of simulated and measured instantaneous power disturbance waveforms of generating units in Łaziska Power Plant. The method for electromechanical eigenvalue calculations used in investigations consists in approximation of the instantaneous power swing waveforms in particular generating units with the use of the waveforms being a superposition of the modal components associated with the searched eigenvalues and their participation factors. The hybrid optimisation algorithm consisting of the genetic and gradient algorithms was used for computations.

  13. Cooperative genome-wide analysis shows increased homozygosity in early onset Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Javier Simón-Sánchez

    Full Text Available Parkinson's disease (PD occurs in both familial and sporadic forms, and both monogenic and complex genetic factors have been identified. Early onset PD (EOPD is particularly associated with autosomal recessive (AR mutations, and three genes, PARK2, PARK7 and PINK1, have been found to carry mutations leading to AR disease. Since mutations in these genes account for less than 10% of EOPD patients, we hypothesized that further recessive genetic factors are involved in this disorder, which may appear in extended runs of homozygosity.We carried out genome wide SNP genotyping to look for extended runs of homozygosity (ROHs in 1,445 EOPD cases and 6,987 controls. Logistic regression analyses showed an increased level of genomic homozygosity in EOPD cases compared to controls. These differences are larger for ROH of 9 Mb and above, where there is a more than three-fold increase in the proportion of cases carrying a ROH. These differences are not explained by occult recessive mutations at existing loci. Controlling for genome wide homozygosity in logistic regression analyses increased the differences between cases and controls, indicating that in EOPD cases ROHs do not simply relate to genome wide measures of inbreeding. Homozygosity at a locus on chromosome19p13.3 was identified as being more common in EOPD cases as compared to controls. Sequencing analysis of genes and predicted transcripts within this locus failed to identify a novel mutation causing EOPD in our cohort.There is an increased rate of genome wide homozygosity in EOPD, as measured by an increase in ROHs. These ROHs are a signature of inbreeding and do not necessarily harbour disease-causing genetic variants. Although there might be other regions of interest apart from chromosome 19p13.3, we lack the power to detect them with this analysis.

  14. Poisonous Weed of Insatiable Lust for Power:Theme Analysis of Macbeth

    Institute of Scientific and Technical Information of China (English)

    刘泽璞

    2014-01-01

    On the basis of an in-depth analysis of the insatiable lust of Macbeth and Lady Macbeth for power, this paper is intend-ed to reveal the theme of Macbeth: the greed for power and the corruption of power in human nature. It is argued that when Macbeth and Lady Macbeth are greedy for political power, they cannot avoid committing regicide. Once seizing the power in such an unlawful and sinister way, they abuse power. Eventually, it is their ugly inner drive for power that inevitably cause their degeneration, downfall and demise. Such a theme analysis has its practical significance for modern readers.

  15. DESIGN AND ANALYSIS OF TURBINE BLADES IN STEAM POWER PLANT SYED

    Directory of Open Access Journals (Sweden)

    ATAUL REHAMAN BASHA

    2014-11-01

    Full Text Available The development of any country directly relates on capital energy consumption. The demand for power generation on the large scale is increasing day by day. Owing to their major contribution towards power production, thermal power plants have a vital role to play in the development of nation. Due to the scarcity of power every power plant needs to be operated at maximum level of efficiency. In case of thermal power plants this applies equally to all its auxiliaries.

  16. Analysis of Interline Power Flow Controller (IPFC Location in Power Transmission Systems

    Directory of Open Access Journals (Sweden)

    Amir Kahyaei

    2011-07-01

    Full Text Available The Interline Power Flow Controller (IPFC is one of the latest generation Flexible AC Transmission Systems (FACTS controller used to control power flows of multiple transmission lines. The aim of this paper is investigation of the effect of location of IPFC on profile of voltage and real and reactive power flow in transmission lines in power system. This model is incorporated in Newton- Raphson (NR power flow algorithm to study the power flow control in transmission lines in which IPFC is placed. A program in MATLAB/SIMULINK has been written in order to extend conventional NR algorithm based on this model. Numerical results are carried out on a standard power system. The results without and with IPFC for various locations are compared in terms of voltages, active and reactive power flows to demonstrate the performance of the IPFC model.

  17. Human Factors Considerations in New Nuclear Power Plants: Detailed Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    OHara,J.; Higgins, J.; Brown, W.; Fink, R.

    2008-02-14

    This Nuclear Regulatory Commission (NRC) sponsored study has identified human-performance issues in new and advanced nuclear power plants. To identify the issues, current industry developments and trends were evaluated in the areas of reactor technology, instrumentation and control technology, human-system integration technology, and human factors engineering (HFE) methods and tools. The issues were organized into seven high-level HFE topic areas: Role of Personnel and Automation, Staffing and Training, Normal Operations Management, Disturbance and Emergency Management, Maintenance and Change Management, Plant Design and Construction, and HFE Methods and Tools. The issues where then prioritized into four categories using a 'Phenomena Identification and Ranking Table' methodology based on evaluations provided by 14 independent subject matter experts. The subject matter experts were knowledgeable in a variety of disciplines. Vendors, utilities, research organizations and regulators all participated. Twenty issues were categorized into the top priority category. This Brookhaven National Laboratory (BNL) technical report provides the detailed methodology, issue analysis, and results. A summary of the results of this study can be found in NUREG/CR-6947. The research performed for this project has identified a large number of human-performance issues for new control stations and new nuclear power plant designs. The information gathered in this project can serve as input to the development of a long-term strategy and plan for addressing human performance in these areas through regulatory research. Addressing human-performance issues will provide the technical basis from which regulatory review guidance can be developed to meet these challenges. The availability of this review guidance will help set clear expectations for how the NRC staff will evaluate new designs, reduce regulatory uncertainty, and provide a well-defined path to new nuclear power plant

  18. Modeling and Analysis of Harmonic Stability in an AC Power-Electronics-Based Power System

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Wu, Weimin

    2014-01-01

    This paper addresses the harmonic stability caused by the interactions among the wideband control of power converters and passive components in an AC power-electronicsbased power system. The impedance-based analytical approach is employed and expanded to a meshed and balanced threephase network...

  19. Seismic margin analysis technique for nuclear power plant structures

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jeong Moon; Choi, In Kil

    2001-04-01

    In general, the Seismic Probabilistic Risk Assessment (SPRA) and the Seismic Margin Assessment(SAM) are used for the evaluation of realistic seismic capacity of nuclear power plant structures. Seismic PRA is a systematic process to evaluate the seismic safety of nuclear power plant. In our country, SPRA has been used to perform the probabilistic safety assessment for the earthquake event. SMA is a simple and cost effective manner to quantify the seismic margin of individual structural elements. This study was performed to improve the reliability of SMA results and to confirm the assessment procedure. To achieve this goal, review for the current status of the techniques and procedures was performed. Two methodologies, CDFM (Conservative Deterministic Failure Margin) sponsored by NRC and FA (Fragility Analysis) sponsored by EPRI, were developed for the seismic margin review of NPP structures. FA method was originally developed for Seismic PRA. CDFM approach is more amenable to use by experienced design engineers including utility staff design engineers. In this study, detailed review on the procedures of CDFM and FA methodology was performed.

  20. Statistical Analysis of Loss of Offsite Power Events

    Directory of Open Access Journals (Sweden)

    Andrija Volkanovski

    2016-01-01

    Full Text Available This paper presents the results of the statistical analysis of the loss of offsite power events (LOOP registered in four reviewed databases. The reviewed databases include the IRSN (Institut de Radioprotection et de Sûreté Nucléaire SAPIDE database and the GRS (Gesellschaft für Anlagen- und Reaktorsicherheit mbH VERA database reviewed over the period from 1992 to 2011. The US NRC (Nuclear Regulatory Commission Licensee Event Reports (LERs database and the IAEA International Reporting System (IRS database were screened for relevant events registered over the period from 1990 to 2013. The number of LOOP events in each year in the analysed period and mode of operation are assessed during the screening. The LOOP frequencies obtained for the French and German nuclear power plants (NPPs during critical operation are of the same order of magnitude with the plant related events as a dominant contributor. A frequency of one LOOP event per shutdown year is obtained for German NPPs in shutdown mode of operation. For the US NPPs, the obtained LOOP frequency for critical and shutdown mode is comparable to the one assessed in NUREG/CR-6890. Decreasing trend is obtained for the LOOP events registered in three databases (IRSN, GRS, and NRC.

  1. Maximum power analysis of photovoltaic module in Ramadi city

    Directory of Open Access Journals (Sweden)

    Majid Shahatha Salim, Jassim Mohammed Najim, Salih Mohammed Salih

    2013-01-01

    Full Text Available Performance of photovoltaic (PV module is greatly dependent on the solar irradiance, operating temperature, and shading. Solar irradiance can have a significant impact on power output of PV module and energy yield. In this paper, a maximum PV power which can be obtain in Ramadi city (100km west of Baghdad is practically analyzed. The analysis is based on real irradiance values obtained as the first time by using Soly2 sun tracker device. Proper and adequate information on solar radiation and its components at a given location is very essential in the design of solar energy systems. The solar irradiance data in Ramadi city were analyzed based on the first three months of 2013. The solar irradiance data are measured on earth's surface in the campus area of Anbar University. Actual average data readings were taken from the data logger of sun tracker system, which sets to save the average readings for each two minutes and based on reading in each one second. The data are analyzed from January to the end of March-2013. Maximum daily readings and monthly average readings of solar irradiance have been analyzed to optimize the output of photovoltaic solar modules. The results show that the system sizing of PV can be reduced by 12.5% if a tracking system is used instead of fixed orientation of PV modules.

  2. Maximum power analysis of photovoltaic module in Ramadi city

    Energy Technology Data Exchange (ETDEWEB)

    Shahatha Salim, Majid; Mohammed Najim, Jassim [College of Science, University of Anbar (Iraq); Mohammed Salih, Salih [Renewable Energy Research Center, University of Anbar (Iraq)

    2013-07-01

    Performance of photovoltaic (PV) module is greatly dependent on the solar irradiance, operating temperature, and shading. Solar irradiance can have a significant impact on power output of PV module and energy yield. In this paper, a maximum PV power which can be obtain in Ramadi city (100km west of Baghdad) is practically analyzed. The analysis is based on real irradiance values obtained as the first time by using Soly2 sun tracker device. Proper and adequate information on solar radiation and its components at a given location is very essential in the design of solar energy systems. The solar irradiance data in Ramadi city were analyzed based on the first three months of 2013. The solar irradiance data are measured on earth's surface in the campus area of Anbar University. Actual average data readings were taken from the data logger of sun tracker system, which sets to save the average readings for each two minutes and based on reading in each one second. The data are analyzed from January to the end of March-2013. Maximum daily readings and monthly average readings of solar irradiance have been analyzed to optimize the output of photovoltaic solar modules. The results show that the system sizing of PV can be reduced by 12.5% if a tracking system is used instead of fixed orientation of PV modules.

  3. Methodology for the analysis and retirement of assets: Power transformers

    Directory of Open Access Journals (Sweden)

    Gustavo Adolfo Gómez-Ramírez

    2015-09-01

    Full Text Available The following article consists of the development of a methodology of the area of the engineering of high voltage for the analysis and retirement of repaired power transformers, based on engineering criteria, in order to establish a correlation between the conditions of the transformer from several points of view: electrical, mechanical, dielectrics and thermal. Realizing an analysis of the condition of the question, there are two situations of great transcendency, first one, the international procedure are a “guide” for the acceptance of new transformers, by what they cannot be applied to the letter for repaired transformers, due to the process itself of degradation that the transformer has suffered with to happen of the years and all the factors that they were carrying to a possible repair. Second one, with base in the most recent technical literature, there have been analyzed articles, which analyze the oil dielectrics and the paper, which correlations are established between the quality of the insulating paper and the furan concentrations in the oils. To finish, great part of the investigation till now realized, it has focused in the analysis of the transformer, from the condition of the dielectric oil, so in most cases, there is not had the possibility of realizing a forensic engineering inside the transformer in operation and of being able this way, of analyzing the components of design who can compromise the integrity and operability of the same one.

  4. Seismic design and analysis of nuclear power plant structures

    Institute of Scientific and Technical Information of China (English)

    Pentti Varpasuo

    2013-01-01

    The seismic design and analysis of nuclear power plant (NPP) begin with the seismic hazard assessment and design ground motion development for the site.The following steps are needed for the seismic hazard assessment and design ground motion development:a.the development of regional seismo-tectonic model with seismic source areas within 500 km radius centered to the site; b.the development of strong motion prediction equations;c.logic three development for taking into account uncertainties and seismic hazard quantification; d.the development of uniform hazard response spectra for ground motion at the site; e.simulation of acceleration time histories compatible with uniform hazard response spectra.The following phase two in seismic design of NPP structures is the analysis of structural response for the design ground motion.This second phase of the process consists of the following steps:a.development of structural models of the plant buildings; b.development of the soil model underneath the plant buildings for soil-structure interaction response analysis; c.determination of in-structure response spectra for the plant buildings for the equipment response analysis.In the third phase of the seismic design and analysis the equipment is analyzed on the basis of in-structure response spectra.For this purpose the structural models of the mechanical components and piping in the plant are set up.In large 3D-structural models used today the heaviest equipment of the primary coolant circuit is included in the structural model of the reactor building.In the fourth phase the electrical equipment and automation and control equipment are seismically qualified with the aid of the in-structure spectra developed in the phase two using large three-axial shaking tables.For this purpose the smoothed envelope spectra for calculated in-structure spectra are constructed and acceleration time is fitted to these smoothed envelope spectra.

  5. Analysis of General Power Counting Rules in Effective Field Theory

    CERN Document Server

    Gavela, B M; Manohar, A V; Merlo, L

    2016-01-01

    We derive the general counting rules for a quantum effective field theory (EFT) in $\\mathsf{d}$ dimensions. The rules are valid for strongly and weakly coupled theories, and predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. The size of cross sections is controlled by the $\\Lambda$ power counting of EFT, not by chiral counting, even for chiral perturbation theory ($\\chi$PT). The relation between $\\Lambda$ and $f$ is generalized to $\\mathsf{d}$ dimensions. We show that the naive dimensional analysis $4\\pi$ counting is related to $\\hbar$ counting. The EFT counting rules are applied to $\\chi$PT, to Standard Model EFT and to the non-trivial case of Higgs EFT, which combines the $\\Lambda$ and chiral counting rules within a single theory.

  6. The silicon solar satellite power system - A net energy analysis

    Science.gov (United States)

    Hannon, B.; Naughton, J. P.

    The physical aspects and net energy balance of a Satellite Solar Power System (SSPS) are examined. The feasibility of operating with or without laser annealing for the cells, possible variations in the total system costs, the projected worth of the energy, and the R&D costs are explored. The energy needed to mine, refine, fabricate, manufacture, launch, and maintain the SSPS materials and structures are included in the energy analysis, and cost-to-energy ratio of energy used to energy produced graphs are provided for the cases of the use or non-use of laser annealing for radiation protection for the solar cells. The resulting energy ratios indicate that the reference SSPS compares unfavorably with coal or nuclear earth-based plants, although further research is necessary to determine what level of technology is actually required for construction of the SSPS.

  7. Analysis of general power counting rules in effective field theory

    Energy Technology Data Exchange (ETDEWEB)

    Gavela, Belen; Merlo, Luca [Universidad Autonoma de Madrid, Instituto de Fisica Teorica, IFT-UAM/CSIC, Madrid (Spain); Jenkins, Elizabeth E.; Manohar, Aneesh V. [University of California at San Diego, Department of Physics, La Jolla, CA (United States); CERN TH Division, Geneva 23 (Switzerland)

    2016-09-15

    We derive the general counting rules for a quantum effective field theory (EFT) in d dimensions. The rules are valid for strongly and weakly coupled theories, and they predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. We show that the size of the cross sections is controlled by the Λ power counting of EFT, not by chiral counting, even for chiral perturbation theory (χPT). The relation between Λ and f is generalized to d dimensions. We show that the naive dimensional analysis 4π counting is related to ℎ counting. The EFT counting rules are applied to χPT, low-energy weak interactions, Standard Model EFT and the non-trivial case of Higgs EFT. (orig.)

  8. Seismic reliability analysis of large electric power systems

    Institute of Scientific and Technical Information of China (English)

    何军; 李杰

    2004-01-01

    Based on the De. Morgan laws and Boolean simplification, a recursive decomposition method is introduced in this paper to identity the main exclusive safe paths and failed paths of a network. The reliability or the reliability bound of a network can be conveniently expressed as the summation of the joint probabilities of these paths. Under the multivariate normal distribution assumption, a conditioned reliability index method is developed to evaluate joint probabilities of various exclusive safe paths and failed paths, and, finally, the seismic reliability or the reliability bound of an electric power system.Examples given in thc paper show that the method is very simple and provides accurate results in the seismic reliability analysis.

  9. Theory analysis and structure optimization design of powered gait orthosis

    Directory of Open Access Journals (Sweden)

    Meng Ning

    2016-03-01

    Full Text Available Patients suffering from paraplegia are special disabled groups in society. In order to help them with lower-limb rehabilitation, a kind of power-assisted gait orthosis is designed. In consideration of the crutches that are rather necessary to keep balance when walking, the effects of crutches on analysis of mechanism cannot be ignored. Based on the gait characteristics, this gait orthosis mechanism is designed, of which the structure is optimized by genetic algorithm and the dynamical model is generated. The periodic movement of hip joints, knee joints, and ankle joints in corrected gait are achieved and the torque can be transferred to the driving force of the back motor and the pushrod according to the orthosis structure. Finally, a verification test shows this design is reasonable and practical.

  10. Analysis of energy-saving dispatch based on energy efficiency for power system with large scale wind power integration

    Science.gov (United States)

    Zou, Lanqing; Zhou, Peng; Li, Shitong; Lin, Li

    2017-01-01

    With the increasing of wind generators and the scale of wind farm, the utilization rate of wind power decreases continually, it is essential to develop an energy-saving dispatching model for the purpose of energy conservation and emission reduction. Firstly, considering some main factors, such as generator operating costs, start-up unit costs, shutdown unit costs, oil consumption and pollutant emission, establish an energy efficiency model. Then, based on the principle of energy-saving dispatch, a model is established which objective is maximizing the energy efficiency. Moreover, in order to realize the priority dispatching of wind power, another model is established which objective is minimizing the wind power shedding. Finally, under the conditions of different installed wind power capacities being integrated into a real region grid, two models are compared and analyzed from perspectives of the society, thermal power enterprise and wind power enterprise.

  11. Analysis of Chain of Events in Major Historic Power Outages

    Directory of Open Access Journals (Sweden)

    HUANG, T.

    2014-08-01

    Full Text Available Contemporary power systems are facing increasing intricate conditions that have never been considered when initially designing the infrastructure, such as malicious threats, accommodating smart grids, etc. As a consequence, blackouts albeit seldom but stubbornly keep appearing from time to time the world around, and demonstrate their devastating capability to create vast damage on both power systems and the society at large. Patterns of the blackout starting from the first triggering events to the system final status have emerged. A framework of a coding system was proposed in this paper in order to capture the common feature in the system evolution during the development of cascades. Cascades in a blackout can be tracked by a chain of events with the help of the codes. It is facile to adopt the framework to build up a knowledge base of blackouts. By applying the proposed framework to 31 selected historic blackouts, most frequent events, effects and origins are identified; the findings can provide useful information for grid designers and security experts for ranking the most imminent issues in their study.

  12. Transient Stability Performance Analysis of Power System Using Facts Devices

    Directory of Open Access Journals (Sweden)

    M. Srinivasa Rao

    2014-02-01

    Full Text Available Transient stability is increasingly important for secure loading. Transient stability evaluation of large scale power systems is an extremely intricate and highly non linear problem. An important function of transient evaluation is to appraise the capability of the power system to with stand serious contingency in time, so that some emergencies or preventive control can be carried out to prevent system breakdown, the fault current so produced is diverted to the capacitor by using dual-STATCOM controller, results proved that voltage is maintained nearly constant, surge currents decreased and oscillations in generator have damped and hence system stability and continuity of supply are enhanced. If for UPFC, replacing series controller with shunt controller, it works as dual STATCOM. It has advantages as series pulse controller is not required and same pulses can be given to both STATCOMs. The shunt controller is so designed to act as low impedance path for short circuit current, thereby surge currents can be diverted to VSC. A general program for transient stability studies to incorporate FACTS devices is developed using MATLAB/SIMULINK.

  13. Carbon Auction Revenue and Market Power: An Experimental Analysis

    Directory of Open Access Journals (Sweden)

    Noah Dormady

    2016-11-01

    Full Text Available State and regional governments in the U.S. and abroad are looking to market-based approaches to mitigating greenhouse gas emissions from the electric sector, and in the U.S. as a compliance approach to meeting the aggressive targets of the Environmental Protection Agency (EPA’s Clean Power Plan. Auction-based approaches, like those used in the Northeast U.S. and California, are both recommended strategies under the Plan and attractive to state governments because they can generate significant revenue from the sale of emissions permits. However, given the nature of imperfect competition in existing electricity markets, particularly at the state and regional level, the issue of market power is a concern at the forefront. This paper provides the results from a controlled laboratory experiment of an auction-based emissions market in the electricity sector. The results show that government revenue from auctioning emissions permits is substantially lower when market concentration is only moderately increased. The results hold significant implications for states and other subnational governments that have high revenue expectations from the auctioning of emissions permits.

  14. Topological Analysis and Mitigation Strategies for Cascading Failures in Power Grid Networks

    CERN Document Server

    Pahwa, Sakshi; Schulz, Noel

    2012-01-01

    Recently, there has been a growing concern about the overload status of the power grid networks, and the increasing possibility of cascading failures. Many researchers have studied these networks to provide design guidelines for more robust power grids. Topological analysis is one of the components of system analysis for its robustness. This paper presents a complex systems analysis of power grid networks. First, the cascading effect has been simulated on three well known networks: the IEEE 300 bus test system, the IEEE 118 bus test system, and the WSCC 179 bus equivalent model. To extend the analysis to a larger set of networks, we develop a network generator and generate multiple graphs with characteristics similar to the IEEE test networks but with different topologies. The generated graphs are then compared to the test networks to show the effect of topology in determining their robustness with respect to cascading failures. The generated graphs turn out to be more robust than the test graphs, showing the...

  15. Analysis of wind power ancillary services characteristics with German 250-MW wind data

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, B.

    1999-12-09

    With the increasing availability of wind power worldwide, power fluctuations have become a concern for some utilities. Under electric industry restructuring in the US, the impact of these fluctuations will be evaluated by examining provisions and costs of ancillary services for wind power. This paper analyzes wind power in the context of ancillary services, using data from a German 250 Megawatt Wind project.

  16. Heat transfer and structure stress analysis of micro packaging component of high power light emitting diode

    Directory of Open Access Journals (Sweden)

    Hsu Chih-Neng

    2013-01-01

    Full Text Available This paper focuses on the heat transfer and structural stress analysis of the micro- scale packaging structure of a high-power light emitting diode. The thermal-effect and thermal-stress of light emitting diode are determined numerically. Light emitting diode is attached to the silicon substrate through the wire bonding process by using epoxy as die bond material. The silicon substrate is etched with holes at the bottom and filled with high conductivity copper material. The chip temperature and structure stress increase with input power consumption. The micro light emitting diode is mounted on the heat sink to increase the heat dissipation performance, to decrease chip temperature, to enhance the material structure reliability and safety, and to avoid structure failure as well. This paper has successfully used the finite element method to the micro-scale light emitting diode heat transfer and stress concentration at the edges through etched holes.

  17. Throughput Analysis of Power Control B-MAC Protocol In WSN

    Directory of Open Access Journals (Sweden)

    Ramchand V

    2012-07-01

    Full Text Available This paper presents a new methodology for energy consumption of nodes and throughput analysis has been performed through simulation for B-MAC protocol in Wireless Sensor Networks. The design includes transmission power control and multi-hop transmission of frames through adjusted transmitted power level. Proposed model reduces collision with contention level notification. The proposed model has been simulated using MATLAB. The simulations reveal better results for throughput of the proposed model as compared to B-MAC protocol. In this model we have included a mechanism for node discovery to find the location of the node before transmission of data to it. This increases the throughput of the network since the position of a dislocated node has been found, that results into successful transmission of frames.However, the energy consumption of a node increases due to energy consumed in node discovery.

  18. Novel wave power analysis linking pressure-flow waves, wave potential, and the forward and backward components of hydraulic power.

    Science.gov (United States)

    Mynard, Jonathan P; Smolich, Joseph J

    2016-04-15

    Wave intensity analysis provides detailed insights into factors influencing hemodynamics. However, wave intensity is not a conserved quantity, so it is sensitive to diameter variations and is not distributed among branches of a junction. Moreover, the fundamental relation between waves and hydraulic power is unclear. We, therefore, propose an alternative to wave intensity called "wave power," calculated via incremental changes in pressure and flow (dPdQ) and a novel time-domain separation of hydraulic pressure power and kinetic power into forward and backward wave-related components (ΠP±and ΠQ±). Wave power has several useful properties:1) it is obtained directly from flow measurements, without requiring further calculation of velocity;2) it is a quasi-conserved quantity that may be used to study the relative distribution of waves at junctions; and3) it has the units of power (Watts). We also uncover a simple relationship between wave power and changes in ΠP±and show that wave reflection reduces transmitted power. Absolute values of ΠP±represent wave potential, a recently introduced concept that unifies steady and pulsatile aspects of hemodynamics. We show that wave potential represents the hydraulic energy potential stored in a compliant pressurized vessel, with spatial gradients producing waves that transfer this energy. These techniques and principles are verified numerically and also experimentally with pressure/flow measurements in all branches of a central bifurcation in sheep, under a wide range of hemodynamic conditions. The proposed "wave power analysis," encompassing wave power, wave potential, and wave separation of hydraulic power provides a potent time-domain approach for analyzing hemodynamics.

  19. UPVapor: Cofrentes nuclear power plant production results analysis software

    Energy Technology Data Exchange (ETDEWEB)

    Curiel, M. [Logistica y Acondicionamientos Industriales SAU, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain); Palomo, M. J. [ISIRYM, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia (Spain); Baraza, A. [Iberdrola Generacion S. A., Central Nuclear Cofrentes, Carretera Almansa Requena s/n, 04662 Cofrentes, Valencia (Spain); Vaquer, J., E-mail: m.curiel@lainsa.co [TITANIA Servicios Tecnologicos SL, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain)

    2010-10-15

    UPVapor software version 02 has been developed for the Cofrentes nuclear power plant Data Analysis Department (Spain). It is an analysis graphical environment in which users have available all the plant variables registered in the process computer system (SIEC). In order to perform this, UPVapor software has many advanced graphic tools for work simplicity, as well as a friendly environment easy to use and with many configuration possibilities. Plant variables are classified in the same way that they are in SIEC computer and these values are taken from it through the network of Iberdrola. UPVapor can generate two different types of graphics: evolution graphs and X Y graphs. The first ones analyse the evolution up to twenty plant variables in a user's defined time period and according to historic plant files. Many tools are available: cursors, graphic configuration, mobile means, non valid data visualization ... Moreover, a particular analysis configuration can be saved, as a pre selection, giving the possibility of charging pre selection directly and developing quick monitoring of a group of preselected plant variables. In X Y graphs, it is possible to analyse a variable value against another variable in a defined time. As an option, users can filter previous data depending on a variable certain range, with the possibility of programming up to five filters. As well as the other graph, X Y graph has many configurations, saving and printing options. With UPVapor software, data analysts can save a valuable time during daily work and, as it is of easy utilization, it permits to other users to perform their own analysis without ask the analysts to develop. Besides, it can be used from any work centre with access to network framework. (Author)

  20. Power Flow Analysis of Island Business District 33KV Distribution Grid System with Real Network Simulations

    Directory of Open Access Journals (Sweden)

    Adesina, L.M

    2015-07-01

    Full Text Available The solution to power flow is one of the most important problems in electrical power systems. Traditional methods have been previously used for power flow analysis, but with prevalent drawbacks such as abnormal operating solutions and divergences in heavy loads. This paper presents power flow analysis in a power system, by modelling a typical 33kV Distribution Network, and simulating using the NEPLAN software for power flow studies. Island Business Unit’s (IBU 33kV network of Eko Electricity Distribution Plc (EKEDP for a scenario day is taken as case study in the analysis. The most important parameters of power flow analysis is utilized to find the magnitude and phase angles of the voltages at each Busbar, as well as the real and reactive power flowing through each distribution line within the network under consideration.

  1. Thermal analysis of wirelessly powered thermo-pneumatic micropump based on planar LC circuit

    Energy Technology Data Exchange (ETDEWEB)

    Chee, Pei Song; Nafea, Marwan; Leow, Pei Ling; Ali, Mohamed Sultan Mohamed [Universiti Teknologi Malaysia, Skudai (Malaysia)

    2016-06-15

    This paper studies the thermal behavior of a wireless powered micropump operated using thermo-pneumatic actuation. Numerical analysis was performed to investigate the temporal conduction of the planar inductor-capacitor (LC) wireless heater and the heating chamber. The result shows that the temperature at the heating chamber reaches steady state temperature of 46.7.deg.C within 40 seconds. The finding was further verified with experimental works through the fabrication of the planar LC heater (RF sensitive actuator) and micropump device using MEMS fabrication technique. The fabricated device delivers a minimum volume of 0.096 μL at the temperature of 29.deg.C after being thermally activated for 10 s. The volume dispensed from the micropump device can precisely controlled by an increase of the electrical heating power within the cut-off input power of 0.22 W. Beyond the power, the heat transfer to the heating chamber exhibits non-linear behavior. In addition, wireless operation of the fabricated device shows successful release of color dye when the micropump is immersed in DI-water containing dish and excited by tuning the RF power.

  2. Analysis of Loss-of-Offsite-Power Events 1998–2012

    Energy Technology Data Exchange (ETDEWEB)

    T. E. Wierman

    2013-10-01

    Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. Risk analyses performed loss of all alternating current power contributes over 70% of the overall risk at some U.S. nuclear plants. LOOP event and subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience from fiscal year 1998 through 2012. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. The EDG failure modes considered are failure to start, failure to load and run, and failure to run more than 1 hour. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. A statistically significant increase in industry performance was identified for plant-centered and switchyard-centered LOOP frequencies. There is no statistically significant trend in LOOP durations.

  3. Long range prospect of the electric power demand in FY 2,000. Total demand: 8. 38 trillion KWh, annual average increase: 2. 3%

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-05

    The Agency of Natural Resources and Energy, the Ministry of International Trade and Industry held meetings of the Committee on Demand and Supply of the Electric Utility Industrial Council in October, 1987. This article is the Committee's interim report and establishes the prospect of the electric power supply and demand in Japan in FY 1995 and FY 2000. Total power demand in FY 1995 is about 7.38 trillion KWh and in FY 2000, about 8.38 trillion KWh. Average annual growth is about 2.6% during the period of FY 1995 through FY 2000. Among the above, the public demand will increase and occupy 50.2% of the total power demand in the year of 2000. The industrial demand will increase about 1.4% in terms of annual rate during the period of FY 1995 through FY 2000 due to the demand increase by new industries, etc. against continued rationalization of power utilization. The maximum electric power demand is around 163 million KW in FY 2000. The target of electric power supply in FY 2000 is 53 million KW from atomic power generation, 23 million KW from coal burning thermal power generation, 43 million KW from LNG, 21 million KW from hydro power generation and 52 million KW from oil and LPG. Hereafter, electric load leveling, more efficient electric power supply and strengthening of the basis of electric power utilization are necessary. (1 photo, 3 tabs)

  4. A shift from significance test to hypothesis test through power analysis in medical research

    Directory of Open Access Journals (Sweden)

    Singh Girish

    2006-01-01

    Full Text Available Medical research literature until recently, exhibited substantial dominance of the Fisher′s significance test approach of statistical inference concentrating more on probability of type I error over Neyman-Pearson′s hypothesis test considering both probability of type I and II error. Fisher′s approach dichotomises results into significant or not significant results with a P value. The Neyman-Pearson′s approach talks of acceptance or rejection of null hypothesis. Based on the same theory these two approaches deal with same objective and conclude in their own way. The advancement in computing techniques and availability of statistical software have resulted in increasing application of power calculations in medical research and thereby reporting the result of significance tests in the light of power of the test also. Significance test approach, when it incorporates power analysis contains the essence of hypothesis test approach. It may be safely argued that rising application of power analysis in medical research may have initiated a shift from Fisher′s significance test to Neyman-Pearson′s hypothesis test procedure.

  5. Comparative Analysis of Power Plant Options for Enhanced Geothermal Systems (EGS

    Directory of Open Access Journals (Sweden)

    Mengying Li

    2014-12-01

    Full Text Available Enhanced geothermal systems (EGS extract heat from underground hot dry rock (HDR by first fracturing the HDR and then circulating a geofluid (typically water into it and bringing the heated geofluid to a power plant to generate electricity. This study focuses on analysis, examination, and comparison of leading geothermal power plant configurations with a geofluid temperature from 200 to 800 °C, and also analyzes the embodied energy of EGS surface power plants. The power generation analysis is focused on flash type cycles for using subcritical geofluid (<374 °C and expansion type cycles for using supercritical geofluid (>374 °C. Key findings of this study include: (i double-flash plants have 24.3%–29.0% higher geofluid effectiveness than single-flash ones, and 3%–10% lower specific embodied energy; (ii the expansion type plants have geofluid effectiveness > 750 kJ/kg, significantly higher than flash type plants (geofluid effectiveness < 300 kJ/kg and the specific embodied energy is lower; (iii to increase the turbine outlet vapor fraction from 0.75 to 0.90, we include superheating by geofluid but that reduces the geofluid effectiveness by 28.3%; (iv for geofluid temperatures above 650 °C, double-expansion plants have a 2% higher geofluid effectiveness and 5%–8% lower specific embodied energy than single-expansion ones.

  6. Green Demonstrated Analysis on Structure of Our Electric Power Resource

    Institute of Scientific and Technical Information of China (English)

    YANG Jun-bao; YU Jing; CHEN Jin-jing

    2004-01-01

    According to green view and history data, the demonstrated method is applied to analyze the green rationality on the present structure of thermal, hydraulic and nuclear electric power resource; the green trend of large-scale on thermal power generating unit in our history; the distribution of between water and coal resource with the space structure of electric power installed capacity, and recommending the premise, dominance and direction of building our green electric power structure in the future.

  7. Power spectrum analysis for defect screening in integrated circuit devices

    Science.gov (United States)

    Tangyunyong, Paiboon; Cole Jr., Edward I.; Stein, David J.

    2011-12-01

    A device sample is screened for defects using its power spectrum in response to a dynamic stimulus. The device sample receives a time-varying electrical signal. The power spectrum of the device sample is measured at one of the pins of the device sample. A defect in the device sample can be identified based on results of comparing the power spectrum with one or more power spectra of the device that have a known defect status.

  8. Analysis of North Sea Offshore Wind Power Variability

    NARCIS (Netherlands)

    Buatois, A.; Gibescu, M.; Rawn, B.G.; Van der Meijden, M.A.M.M.

    2014-01-01

    This paper evaluates, for a 2030 scenario, the impact on onshore power systems in terms of the variability of the power generated by 81 GW of offshore wind farms installed in the North Sea. Meso-scale reanalysis data are used as input for computing the hourly power production for offshore wind farms

  9. Newton-Krylov Methods in Power Flow and Contingency Analysis

    NARCIS (Netherlands)

    Idema, R.

    2012-01-01

    A power system is a system that provides for the generation, transmission, and distribution of electrical energy. Power systems are considered to be the largest and most complex man-made systems. As electrical energy is vital to our society, power systems have to satisfy the highest security and re

  10. Integrating Wind Power in Electricity Grids : an Economic Analysis

    NARCIS (Netherlands)

    Liu, J.; Kooten, van G.C.; Pitt, L.

    2005-01-01

    As a renewable energy source, wind power is gaining popularity as a favoured alternative to fossil fuel, nuclear and hydro power generation. In Europe, countries are required to achieve 15% of their energy consumption from wind by 2010 as the EU strives to meet its Kyoto obligations. Wind power is c

  11. Performance analysis of a zeotropic mixture (R290/CO2) for trans-critical power cycle☆

    Institute of Scientific and Technical Information of China (English)

    Lisheng Pan; Xiaolin Wei; Weixiu Shi

    2015-01-01

    Low critical temperature limits the application of CO2 trans-critical power cycle. The binary mixture of R290/CO2 has higher critical temperature. Using mixture fluid may solve the problem that subcritical CO2 is hardly con-densed by conventional cooling water. In this article, theoretical analysis is executed to study the performance of the zeotropic mixture for trans-critical power cycle using low-grade liquid heat source with temperature of 200 °C. The results indicated that the problem that CO2 can't be condensed in power cycle by conventional cooling water can be solved by mixing R290 to CO2. Variation trend of outlet temperature of thermal oil in super-critical heater with heating pressure is determined by the composition of the mixture fluid. Gliding temperature causes the maximum outlet temperature of cooling water with the increase of mass fraction of R290. There are the maximum values for cycle thermal efficiency and net power output with the increase of supercritical heating pressure.

  12. Repetitive transcranial magnetic stimulation improves consciousness disturbance in stroke patients A quantitative electroencephalography spectral power analysis

    Institute of Scientific and Technical Information of China (English)

    Ying Xie; Tong Zhang

    2012-01-01

    Repetitive transcranial magnetic stimulation is a noninvasive treatment technique that can directly alter cortical excitability and improve cerebral functional activity in unconscious patients. To investigate the effects and the electrophysiological changes of repetitive transcranial magnetic stimulation cortical treatment, 10 stroke patients with non-severe brainstem lesions and with disturbance of consciousness were treated with repetitive transcranial magnetic stimulation. A quantitative electroencephalography spectral power analysis was also performed. The absolute power in the alpha band was increased immediately after the first repetitive transcranial magnetic stimulation treatment, and the energy was reduced in the delta band. The alpha band relative power values slightly decreased at 1 day post-treatment, then increased and reached a stable level at 2 weeks post-treatment. Glasgow Coma Score and JFK Coma Recovery Scale-Revised score were improved. Relative power value in the alpha band was positively related to Glasgow Coma Score and JFK Coma Recovery Scale-Revised score. These data suggest that repetitive transcranial magnetic stimulation is a noninvasive, safe, and effective treatment technology for improving brain functional activity and promoting awakening in unconscious stroke patients.

  13. Comprehensive analysis of a straw-fired power plant in Vojvodina

    Directory of Open Access Journals (Sweden)

    Urošević Dragan M.

    2012-01-01

    Full Text Available In recent years, renewable energy sources have played an increasingly important role in potential energy production. The integration of renewable energy technologies into existing national energy system has therefore become a major challenge for many countries. Due to the importance of this matter, this paper deals with the comprehensive analysis for implementation of a power plant on biomass (straw. The analysis is conducted regarding several key indicators: availability of biomass, regulation, reduction of greenhouse gas emissions, location, land use, electricity price and social impacts. The analysis also includes favorable price for electricity produced from biomass relevant to national feed in tariffs. In order to demonstrate all above mentioned indicators, the region in Serbia (Province of Vojvodina with significant potential in biomass, especially in straw, is selected. The results of the analysis are validated trough environmental and social aspects. Special attention is given to identifying risks for this application.

  14. Independent Orbiter Assessment (IOA): Analysis of the electrical power distribution and control/electrical power generation subsystem

    Science.gov (United States)

    Patton, Jeff A.

    1986-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Electrical Power Distribution and Control (EPD and C)/Electrical Power Generation (EPG) hardware. The EPD and C/EPG hardware is required for performing critical functions of cryogenic reactant storage, electrical power generation and product water distribution in the Orbiter. Specifically, the EPD and C/EPG hardware consists of the following components: Power Section Assembly (PSA); Reactant Control Subsystem (RCS); Thermal Control Subsystem (TCS); Water Removal Subsystem (WRS); and Power Reactant Storage and Distribution System (PRSDS). The IOA analysis process utilized available EPD and C/EPG hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode.

  15. Time series power flow analysis for distribution connected PV generation.

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, Robert Joseph; Quiroz, Jimmy Edward; Ellis, Abraham; Reno, Matthew J.; Smith, Jeff; Dugan, Roger

    2013-01-01

    Distributed photovoltaic (PV) projects must go through an interconnection study process before connecting to the distribution grid. These studies are intended to identify the likely impacts and mitigation alternatives. In the majority of the cases, system impacts can be ruled out or mitigation can be identified without an involved study, through a screening process or a simple supplemental review study. For some proposed projects, expensive and time-consuming interconnection studies are required. The challenges to performing the studies are twofold. First, every study scenario is potentially unique, as the studies are often highly specific to the amount of PV generation capacity that varies greatly from feeder to feeder and is often unevenly distributed along the same feeder. This can cause location-specific impacts and mitigations. The second challenge is the inherent variability in PV power output which can interact with feeder operation in complex ways, by affecting the operation of voltage regulation and protection devices. The typical simulation tools and methods in use today for distribution system planning are often not adequate to accurately assess these potential impacts. This report demonstrates how quasi-static time series (QSTS) simulation and high time-resolution data can be used to assess the potential impacts in a more comprehensive manner. The QSTS simulations are applied to a set of sample feeders with high PV deployment to illustrate the usefulness of the approach. The report describes methods that can help determine how PV affects distribution system operations. The simulation results are focused on enhancing the understanding of the underlying technical issues. The examples also highlight the steps needed to perform QSTS simulation and describe the data needed to drive the simulations. The goal of this report is to make the methodology of time series power flow analysis readily accessible to utilities and others responsible for evaluating

  16. Remaining Life Analysis of Boiler Tubes on Behalf of Hoop Stresses Produced During Operation of Power Plant

    Directory of Open Access Journals (Sweden)

    Mohd. Zeeshan Gauri

    2014-07-01

    Full Text Available Boiler tube material plays an important role in efficient power generation from a fossil fuel power plant. In order to meet out the gap between fluids to increase heat available per unit mass flow of steam. Waste heat utilization phenomenon is a big challenge on fossil fuel power plants as after use of high grade coal in thermal power plants the efficiency of power plants is not at the level of required value. Clean and efficient power generation with economical aspects is the basic need of growing power generation plants to justify the quality of power and clean power generation. Life analysis technique to calculate remaining life of boiler tubes at critical zones of high temperature requires much attention and is an important hypothesis in research field. Generation of repetitive and fluctuating stress during flow of high temperature and pressure fluid require proper attention on the methodology to be used to calculate the efficiency of system and absorption efficiency of tube material. In this paper complete mathematical analysis of boiler tubes is conducted for calculation of remaining life of boiler tubes, Hoop stress values are calculated and used with mathematical tool to calculate the efficiency. Hoop stress based calculation of efficiency is more reliable and may give more accurate and practical aspects based results.

  17. Thermal design and analysis of high power star sensors

    Directory of Open Access Journals (Sweden)

    Fan Jiang

    2015-09-01

    Full Text Available The requirement for the temperature stability is very high in the star sensors as the high precision needs for the altitude information. Thermal design and analysis thus is important for the high power star sensors and their supporters. CCD, normally with Peltier thermoelectric cooler (PTC, is the most important sensor component in the star sensors, which is also the main heat source in the star sensors suite. The major objective for the thermal design in this paper is to design a radiator to optimize the heat diffusion for CCD and PTC. The structural configuration of star sensors, the heat sources and orbit parameters were firstly introduced in this paper. The influences of the geometrical parameters and coating material characteristics of radiators on the heat diffusion were investigated by heat flux analysis. Carbon–carbon composites were then chosen to improve the thermal conductivity for the sensor supporters by studying the heat transfer path. The design is validated by simulation analysis and experiments on orbit. The satellite data show that the temperatures of three star sensors are from 17.8 °C to 19.6 °C, while the simulation results are from 18.1 °C to 20.1 °C. The temperatures of radiator are from 16.1 °C to 16.8 °C and the corresponding simulation results are from 16.0 °C to 16.5 °C. The temperature variety of each star sensor is less than 2 °C, which satisfies the design objectives.

  18. Application of Designing Economic Mechanisms to Power Market - Part 2 Characteristic Analysis of Generation Side Power Market

    OpenAIRE

    Zhu, Yonggang; XIE Qingyang; Ying, Liming

    2013-01-01

    The incentive power market may lead to a high information cost if it is not informationally efficient. The paper analyzes the characteristic of the generation side power market mechanism model based on the designing economic mechanisms theory by the three GENCOs (Generation Companies) case. The result of analysis is that the mechanism model has four main features: the informationally efficient which means that the mechanism meets requirements of the observational efficiency, the communication...

  19. A preliminary design and BOP cost analysis of M-C Power`s MCFC commerical unit

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.P. [Bechtel Corp, San Francisco, CA (United States)

    1996-12-31

    M-C Power Corporation plans to introduce its molten carbonate fuel cell (MCFC) market entry unit in the year 2000 for distributed and on-site power generation. Extensive efforts have been made to analyze the cell stack manufacturing costs. The major objective of this study is to conduct a detailed analysis of BOP costs based on an initial design of the market entry unit.

  20. Exergy analysis of a combined heat and power plant with integrated lignocellulosic ethanol production

    DEFF Research Database (Denmark)

    Lythcke-Jørgensen, Christoffer Ernst; Haglind, Fredrik; Clausen, Lasse Røngaard

    2013-01-01

    Integrating second generation bioethanol production in combined heat and power units is expected to increase system energy efficiencies while producing sustainable fuel for the transportation sector at a competitive price. By applying exergy analysis, this study assessed the efficiency of an inte......Integrating second generation bioethanol production in combined heat and power units is expected to increase system energy efficiencies while producing sustainable fuel for the transportation sector at a competitive price. By applying exergy analysis, this study assessed the efficiency...... unit solely. The exergy flows inside the ethanol facility were determined, and the exergy in steam flows into and out of the system components were determined by combining exergy analysis with pinch analysis and setting a constant heat exchange temperature difference of 10K. The ethanol facility...... produces ethanol, solid biofuel, molasses, and is able to produce district heating hot water. Considering all products equally valuable, the exergy efficiency of the ethanol facility was found to be 0.790 during integrated operation with zero district heating production, and 0.852 during integrated...

  1. Power analysis of artificial selection experiments using efficient whole genome simulation of quantitative traits.

    Science.gov (United States)

    Kessner, Darren; Novembre, John

    2015-04-01

    Evolve and resequence studies combine artificial selection experiments with massively parallel sequencing technology to study the genetic basis for complex traits. In these experiments, individuals are selected for extreme values of a trait, causing alleles at quantitative trait loci (QTL) to increase or decrease in frequency in the experimental population. We present a new analysis of the power of artificial selection experiments to detect and localize quantitative trait loci. This analysis uses a simulation framework that explicitly models whole genomes of individuals, quantitative traits, and selection based on individual trait values. We find that explicitly modeling QTL provides qualitatively different insights than considering independent loci with constant selection coefficients. Specifically, we observe how interference between QTL under selection affects the trajectories and lengthens the fixation times of selected alleles. We also show that a substantial portion of the genetic variance of the trait (50-100%) can be explained by detected QTL in as little as 20 generations of selection, depending on the trait architecture and experimental design. Furthermore, we show that power depends crucially on the opportunity for recombination during the experiment. Finally, we show that an increase in power is obtained by leveraging founder haplotype information to obtain allele frequency estimates.

  2. "The Heart Truth:" Using the Power of Branding and Social Marketing to Increase Awareness of Heart Disease in Women.

    Science.gov (United States)

    Long, Terry; Taubenheim, Ann; Wayman, Jennifer; Temple, Sarah; Ruoff, Beth

    2008-03-01

    In September 2002, the National Heart, Lung, and Blood Institute launched The Heart Truth, the first federally-sponsored national campaign aimed at increasing awareness among women about their risk of heart disease. A traditional social marketing approach, including an extensive formative research phase, was used to plan, implement, and evaluate the campaign. With the creation of the Red Dress as the national symbol for women and heart disease awareness, the campaign integrated a branding strategy into its social marketing framework. The aim was to develop and promote a women's heart disease brand that would create a strong emotional connection with women. The Red Dress brand has had a powerful appeal to a wide diversity of women and has given momentum to the campaign's three-part implementation strategy of partnership development, media relations, and community action. In addition to generating its own substantial programming, The Heart Truth became a catalyst for a host of other national and local educational initiatives, both large and small. By the campaign's fifth anniversary, surveys showed that women were increasingly aware of heart disease as their leading cause of death and that the rise in awareness was associated with increased action to reduce heart disease risk.

  3. Performance and Analysis of Reactive Power Compensation by Unified Power Flow Controller

    Directory of Open Access Journals (Sweden)

    Yogita Kumari

    2015-09-01

    Full Text Available The Unified Power Flow Controller (UPFC is the most versatile of the FACTS controllers envisaged so far. The main function of the UPFC is to control the flow of real and reactive power by injection of a voltage in series with the transmission line. Both the magnitude and the phase angle of the voltage can be varied independently. Real and Reactive power flow control can allow for power flow in prescribed routes, loading of transmission lines close to their thermal limits and can be utilized for improving transient and small signal stability of the power system. In this paper UPFC is incorporated in a SMIB (Single Machine Infinite Bus system and the response of SMIB system has been recorded with and without UPFC, thereafter the comparison of both the output has been done. When no UPFC is installed, real and reactive power through the transmission line cannot be controlled. This paper presents control and performance of UPFC intended for installation on that transmission line to control power flow. Installing the UPFC makes it possible to control amount of active power flowing through the line. Simulations are carried out using MATLAB software to validate the performance of the UPFC.

  4. Analysis of Development of Nationwide Power Sources in 2007 and Forecast for 2008

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ ● Introduction With ever-increasing of power sources, the capability of power supply was further enforced in 2007. This met the strong demand of national economy development. Restructuring of power sources was deepening, of which "substituting large power units for small ones" started well, the installed capacity of wind power was doubled and obvious results were achieved in the energy-conservation and pollutant-reduction.

  5. Modeling and Power Flow Analysis for Herringbone Gears Power Dual-Branching Transmission System

    Science.gov (United States)

    Yang, Xiaofang; Zhu, Yanxiang; Fang, Zongde; Gu, Jiangong

    Based on power dual-branching transmission system of herringbone gears, the mechanical structural model was established. This study represented the simplified algorithm to obtain its power flow situations through formulating the deformation compatibility condition for the linear relationship between the torque and transverse deformation of tooth surface and the torque equilibrium condition. Besides, the effects on the power flow of system were calculated under all kinds of the installation error and processing error of gear pairs. Finally, the power flow situations of dual branches were solved via Programming. A numerical example that illustrated the developed theory was provided. The research results can be applied to analyze the actual application of herringbone gears power split-path transmission system.

  6. Combining Multiple Hypothesis Testing with Machine Learning Increases the Statistical Power of Genome-wide Association Studies

    Science.gov (United States)

    Mieth, Bettina; Kloft, Marius; Rodríguez, Juan Antonio; Sonnenburg, Sören; Vobruba, Robin; Morcillo-Suárez, Carlos; Farré, Xavier; Marigorta, Urko M.; Fehr, Ernst; Dickhaus, Thorsten; Blanchard, Gilles; Schunk, Daniel; Navarro, Arcadi; Müller, Klaus-Robert

    2016-11-01

    The standard approach to the analysis of genome-wide association studies (GWAS) is based on testing each position in the genome individually for statistical significance of its association with the phenotype under investigation. To improve the analysis of GWAS, we propose a combination of machine learning and statistical testing that takes correlation structures within the set of SNPs under investigation in a mathematically well-controlled manner into account. The novel two-step algorithm, COMBI, first trains a support vector machine to determine a subset of candidate SNPs and then performs hypothesis tests for these SNPs together with an adequate threshold correction. Applying COMBI to data from a WTCCC study (2007) and measuring performance as replication by independent GWAS published within the 2008-2015 period, we show that our method outperforms ordinary raw p-value thresholding as well as other state-of-the-art methods. COMBI presents higher power and precision than the examined alternatives while yielding fewer false (i.e. non-replicated) and more true (i.e. replicated) discoveries when its results are validated on later GWAS studies. More than 80% of the discoveries made by COMBI upon WTCCC data have been validated by independent studies. Implementations of the COMBI method are available as a part of the GWASpi toolbox 2.0.

  7. The effect analysis of strain rate on power transmission tower-line system under seismic excitation.

    Science.gov (United States)

    Tian, Li; Wang, Wenming; Qian, Hui

    2014-01-01

    The effect analysis of strain rate on power transmission tower-line system under seismic excitation is studied in this paper. A three-dimensional finite element model of a transmission tower-line system is created based on a real project. Using theoretical analysis and numerical simulation, incremental dynamic analysis of the power transmission tower-line system is conducted to investigate the effect of strain rate on the nonlinear responses of the transmission tower and line. The results show that the effect of strain rate on the transmission tower generally decreases the maximum top displacements, but it would increase the maximum base shear forces, and thus it is necessary to consider the effect of strain rate on the seismic analysis of the transmission tower. The effect of strain rate could be ignored for the seismic analysis of the conductors and ground lines, but the responses of the ground lines considering strain rate effect are larger than those of the conductors. The results could provide a reference for the seismic design of the transmission tower-line system.

  8. COINTEGRATION ANALYSIS OF PURCHASING POWER PARITY IN REPUBLIC OF CROATIA

    Directory of Open Access Journals (Sweden)

    Ivan Kozul

    2013-12-01

    Full Text Available This paper examines the validity of purchasing power parity (PPP hypothesis in the Republic of Croatia. The main aim is to test whether the PPP Theory holds in the case of the Republic of Croatia and whether the PPP Theory is an appropriate method on which monetary policy makers can rely in determining the size of the market exchange rate deviations from its long-run value. The PPP Theory in the Republic of Croatia has been tested using methods of cointegration analysis. Two cointegration tests have been applied: Engle-Granger test and ADL test. The existence of the long-run relationship between the price level in the EMU (expressed in Croatian Kuna and the price level in the Republic of Croatia has been tested using monthly observations of average nominal Croatian Kuna exchange rate against Euro, Consumer Prices Index in the Republic of Croatia (2005=100 and the Harmonised Index of Consumer Prices for the European Monetary Union (2005=100 in the period from January 2000. to December 2012. Based on the Engle-Granger test, it can't be concluded if there is a long-run relationship between the two price levels. The non-existence of the long-run relationship between two price levels has also been confirmed by the ADL cointegration test. Thus, on the basis of the cointegration tests it can be concluded that the PPP hypothesis in the Republic of Croatia has not been confirmed.

  9. Trend analysis of UNFCCC and countermeasures of power industry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.H.; Na, I.K.; Seo, J.H. [Korea Energy Economics Institute, Euiwang (Korea, Republic of)

    1998-06-01

    UNFCCC (United Nations Framework Convention on Climate Change) emerges as an important factor to bring big changes to all fields such as economy, society, culture, etc. as well as environment of the world. Esp., the Kyoto Protocol adopted on December, 1997 is expected to form new current to the world economic order by introducing brand new system such as emission rights trading system, joint carry-out, clean development apparatus, etc. This study looked into the current trend of negotiation in UNFCCC, forecast, and our countermeasure plans, and esp., analyzed the emission rights trading system, countermeasure and utilization plan of joint carry-out centered on power industry. According to this analysis, Korea should hurry up the cooperation and entry with prospective countries such as Eastern Europe, Southeast Asia, and North Korea, etc. for the positive utilization of emission rights trading system and joint carry-out and establish an integrated management system of green-house gases by building an agency that assumes full responsibility of emission rights trading system and joint carry-out since its reduction costs of green-house gases is high. 31 refs., 2 figs., 60 tabs.

  10. Power Spectral Analysis of Heart Rate Variability of Driver Fatigue

    Institute of Scientific and Technical Information of China (English)

    JIAO Kun; LI Zeng-yong; CHEN Ming; WANG Cheng-tao

    2005-01-01

    This investigation was to evaluate the driving fatigue based on power spectral analysis of heart rate variability (HRV) under vertical vibration. Forty healthy male subjects (29.7±3.5 years) were randomly divided into two groups, Group A (28.8±4.3 years) and Group B (30.6±2.7 years). Group A (experiment group) was required to perform the simulated driving and Group B (control group) kept calm for 90min. The frequency domain indices of HRV such as low frequency (0.040.15 Hz, LF), high frequency (0.15-0.4Hz, HF), LF/HF together with the indices of hemodynamics such as blood pressure (BP) and heart rate (HR) of the subjects between both groups were calculated and analyzed after the simulated driving. There were significances of the former indices between both groups (P<0.05). All the data collected after experiment of Group A was observed the remarkable linear correlation (P<0.05) and parameters and errors of their linear regression equation were stated (α=0.05, P<0.001) in this paper, respectively. The present study investigated that sympathetic activity of the subjects enhanced after the simulated driving while parasympathetic activities decreased. The sympathovagal balance was also improved. As autonomic function indictors of HRV reflected fatigue level, quantitative evaluation of driving mental fatigue from physiological reaction could be possible.

  11. Performance of power sectors in developing countries - a study of efficiency and World Bank policy using data development analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hawdon, D.

    1996-08-01

    A substantial proportion of investment in the electric power sectors of developing countries has historically consisted of World Bank loans. At the same time, power sector lending has played a large part in the total lending of the World Bank itself. This paper uses data envelopment analysis (DEA) to construct performance measures for 82 developing countries power sectors in order to evaluate World Bank policy. It examines the effectiveness of World bank lending activity in relation to measured technical, scale and congestion efficiencies. Policies promoting the privatisation of electricity generation and the increased emphasis on lending to Sub Saharan Africa are also evaluated. 11 tabs.

  12. Simulation and reliability analysis of shunt active power filter based on instantaneous reactive power theory

    Institute of Scientific and Technical Information of China (English)

    CUI Yu-long; LIU Hong; WANG Jing-qin; SUN Shu-guang

    2007-01-01

    This paper first discusses the operating principle ofinstantaneous reactive power theory. Then, the theory is introduced into shunt active power filter and its control scheme is studied. Finally, Matlab/Simulink power system toolbox is used to simulate the system. In the simulation model, as the most common harmonic source, 3-phase thyfistor bridge rectifier circuit is constructed.The simulation results before and after the shunt active filter was switched to the system corresponding to different firing angles of the thyristors are presented and analyzed, which demonstrate the practicability and reliability of the proposed shunt active filter scheme.

  13. Post-processing of polymer foam tissue scaffolds with high power ultrasound: A route to increased pore interconnectivity, pore size and fluid transport

    Energy Technology Data Exchange (ETDEWEB)

    Watson, N.J. [School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT (United Kingdom); Johal, R.K. [Division of Immunology, School of Molecular Medical Sciences, Queen' s Medical Centre, University of Nottingham, Nottingham NG7 2UH (United Kingdom); Glover, Z. [School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT (United Kingdom); Reinwald, Y.; White, L.J. [School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Ghaemmaghami, A.M. [Division of Immunology, School of Molecular Medical Sciences, Queen' s Medical Centre, University of Nottingham, Nottingham NG7 2UH (United Kingdom); Morgan, S.P. [Electrical Systems and Optics Research Division, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Rose, F.R.A.J. [School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Povey, M.J.W. [School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT (United Kingdom); Parker, N.G., E-mail: nick.parker@ncl.ac.uk [School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT (United Kingdom); School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2013-12-01

    The aim of this work is to demonstrate that the structural and fluidic properties of polymer foam tissue scaffolds, post-fabrication but prior to the introduction of cells, can be engineered via exposure to high power ultrasound. Our analysis is supported by measurements of fluid uptake during insonification and imaging of the scaffold microstructure via X-ray computed tomography, scanning electron microscopy and acoustic microscopy. The ultrasonic treatment is performed with a frequency of 30 kHz, average intensities up to 80,000 Wm{sup −2} and exposure times up to 20 h. The treatment is found to increase the mean pore size by over 10%. More striking is the improvement in fluid uptake: for scaffolds with only 40% water uptake via standard immersion techniques, we can routinely achieve full saturation of the scaffold over approximately one hour of exposure. These desirable modifications occur with negligible loss of scaffold integrity and mass, and are optimized when the ultrasound treatment is coupled to a pre-wetting stage with ethanol. Our findings suggest that high power ultrasound is highly targeted towards flow obstructions in the scaffold architecture, thereby providing an efficient means to promote pore interconnectivity and fluid transport in thick foam tissue scaffolds. - Highlights: • We expose thick PLA foam tissue scaffolds to high power ultrasound. • This treatment both accelerates and enhances the uptake of fluid into the scaffold. • It leads to significant increases in the mean pore size, pore interconnectivity and porosity. • The ultrasonic treatment is most effective when the scaffold is pre-wet with ethanol. • We demonstrate the use of acoustic microscopy to characterize the scaffold microstructure.

  14. Modifications of EEG power spectra in mesial temporal lobe during n-back tasks of increasing difficulty. A sLORETA study.

    Science.gov (United States)

    Imperatori, Claudio; Farina, Benedetto; Brunetti, Riccardo; Gnoni, Valentina; Testani, Elisa; Quintiliani, Maria I; Del Gatto, Claudia; Indraccolo, Allegra; Contardi, Anna; Speranza, Anna M; Della Marca, Giacomo

    2013-01-01

    The n-back task is widely used to investigate the neural basis of Working Memory (WM) processes. The principal aim of this study was to explore and compare the EEG power spectra during two n-back tests with different levels of difficulty (1-back vs. 3-back). Fourteen healthy subjects were enrolled (seven men and seven women, mean age 31.21 ± 7.05 years, range: 23-48). EEG was recorded while performing the N-back test, by means of 19 surface electrodes referred to joint mastoids. EEG analysis were conducted by means of the standardized Low Resolution brain Electric Tomography (sLORETA) software. The statistical comparison between EEG power spectra in the two conditions was performed using paired t-statistics on the coherence values after Fisher's z transformation available in the LORETA program package. The frequency bands considered were: delta (0.5-4 Hz); theta (4.5-7.5 Hz); alpha (8-12.5 Hz); beta (13-30 Hz); gamma (30.5-100 Hz). Significant changes occurred in the delta band: in the 3-back condition an increased delta power was localized in a brain region corresponding to the Brodmann Area (BA) 28 in the left posterior entorhinal cortex (T = 3.112; p < 0.05) and in the BA 35 in the left perirhinal cortex in the parahippocampal gyrus (T = 2.876; p < 0.05). No significant differences were observed in the right hemisphere and in the alpha, theta, beta, and gamma frequency bands. Our results indicate that the most prominent modification induced by the increased complexity of the task occur in the mesial left temporal lobe structures.

  15. Modifications of EEG Power Spectra in Mesial Temporal Lobe during n-back tasks of increasing difficulty. A sLORETA study.

    Directory of Open Access Journals (Sweden)

    Claudio eImperatori

    2013-04-01

    Full Text Available The n-back task is widely used to investigate the neural basis of Working Memory (WM processes. The principal aim of this study was to explore and compare the EEG power spectra during two n-back tests with different levels of difficulty (1-back vs 3-back.Fourteen healthy subjects were enrolled (7 men and 7 women, mean age 31.21±7.05 years, range: 23-48. EEG was recorded while performing the N-back test, by means of 19 surface electrodes referred to joint mastoids. EEG analysis were conducted by means of the standardized LOw Resolution brain Electric Tomography (sLORETA software. The statistical comparison between EEG power spectra in the two conditions was performed using paired t-statistics on the coherence values after Fisher’s z transformation available in the LORETA program package. The frequency bands considered were: delta (0.5-4 Hz; theta (4.5–7.5 Hz; alpha (8–12.5 Hz; beta (13–30 Hz; gamma (30.5–100 Hz. Significant changes occurred in the delta band: in the 3-back condition an increased delta power was localized in a brain region corresponding to the Brodmann Area (BA 28 in the left posterior entorhinal cortex (T = 3.112; p<0.05 and in the BA 35 in the left peririnhal cortex in the parahippocampal gyrus (T = 2.876; p<0.05. No significant differences were observed in the right hemisphere and in the alpha, theta, beta and gamma frequency bands. Our results indicate that the most prominent modification induced by the increased complexity of the task occur in the mesial left temporal lobe structures.

  16. Transient analysis of power systems solution techniques, tools and applications

    CERN Document Server

    Martinez-Velasco, J

    2014-01-01

    A comprehensive introduction and up-to-date reference to SiC power semiconductor devices covering topics from material properties to applicationsBased on a number of breakthroughs in SiC material science and fabrication technology in the 1980s and 1990s, the first SiC Schottky barrier diodes (SBDs) were released as commercial products in 2001.  The SiC SBD market has grown significantly since that time, and SBDs are now used in a variety of power systems, particularly switch-mode power supplies and motor controls.  SiC power MOSFETs entered commercial production in 2011, providing rugged, hig

  17. Analysis of power transients in a cascade of EDFAs

    Institute of Scientific and Technical Information of China (English)

    ZhangyuanChen; GuishengXiong; 等

    1997-01-01

    Power transients in a cascade of EDFAs are investigated by numerical simulations.The rate of transient response induced by the channel number variation is found to scale with the number of EDFAs and overshoots and relax oscilations are observed after several EDFAs.The slope of 1-dB power change time scales linearly with the number of EDFAs.The influence of pump variation on the output is large for a single EDFA,but small after many EDFAs.The response of power control must be fast enough to limit the power excursion.

  18. Analysis of North Sea Offshore Wind Power Variability

    Directory of Open Access Journals (Sweden)

    Aymeric Buatois

    2014-05-01

    Full Text Available This paper evaluates, for a 2030 scenario, the impact on onshore power systems in terms of the variability of the power generated by 81 GW of offshore wind farms installed in the North Sea. Meso-scale reanalysis data are used as input for computing the hourly power production for offshore wind farms, and this total production is analyzed to identify the largest aggregated hourly power variations. Based on publicly available information, a simplified representation of the coastal power grid is built for the countries bordering the North Sea. Wind farms less than 60 km from shore are connected radially to the mainland, while the rest are connected to a hypothetical offshore HVDC (High-Voltage Direct Current power grid, designed such that wind curtailment does not exceed 1% of production. Loads and conventional power plants by technology and associated cost curves are computed for the various national power systems, based on 2030 projections. Using the MATLAB-based MATPOWER toolbox, the hourly optimal power flow for this regional hybrid AC/DC grid is computed for high, low and medium years from the meso-scale database. The largest net load variations are evaluated per market area and related to the extra load-following reserves that may be needed from conventional generators.

  19. Location Refinement and Power Coverage Analysis Based on Distributed Antenna

    Institute of Scientific and Technical Information of China (English)

    赵晓楠; 侯春萍; 汪清; 陈华; 浦亮洲

    2016-01-01

    To establish wireless channel suitable for the cabin environment, the power coverage was investigated with distributed antenna system and centralized antenna system based on the actual measurement of channel im-pulse response. The results indicated that the distributed antenna system has more uniform power coverage than the centralized antenna system. The average relative errors of receiving power of both antennas were calculated. The optimal position of the centralized antenna was obtained by Gaussian function refinement, making the system achieve a better transmission power with the same coverage effect, and providing a reference for antenna location in the future real communication in the cabin.

  20. Analysis of superconducting microstrip resonator at various microwave power levels

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, G.P.; Jacob, M.V.; Jayakumar, M.; Bhatnagar, P.K. [Department of Electronic Science, University of Delhi, South Campus, Benito Juarez Road, New Delhi 110021 (India); Kataria, N.D. [National Physical Laboratory, K. S. Krishnan Road, New Delhi 110 012 (India)

    1997-05-01

    The real and imaginary parts of the surface impedance of YBCO superconductors have been studied at different microwave power levels. Using the relations for the critical current density and the grain boundary resistance, a relation for calculating the power dependence of the surface resistance has been obtained. Also, a relation to find the resonant frequency of a superconducting microstrip resonator at various input power levels has been derived. Measurements have been carried out on various microstrip resonators to study the variation of surface resistance and resonant frequency at different rf power levels. The experimental results are in good agreement with theoretical results. {copyright} {ital 1997 American Institute of Physics.}

  1. Initial Northwest Power Act Power Sales Contracts : Final Environmental Impact Statement. Volume 1, Environmental Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1992-01-01

    This is volume 1 of the final environmental impact statement of the Bonneville Power Administration Information is included on the following: Purpose of and need for action; alternatives including the proposed action; affected environment; and environmental consequences.

  2. Roundoff noise analysis for digital signal power processors using Welch's power spectrum estimation

    Science.gov (United States)

    Chi, Chong-Yung; Long, David; Li, Fuk-Kwok

    1987-01-01

    The noise due to finite-word-length effects is analyzed for digital-signal power processors using Welch's power-spectrum estimation technique to measure the power of Gaussian random signals over a frequency band of interest. The input of the digital signal processor contains a finite-length time interval in which the true Gaussian signal is contaminated by Gaussian noise. The roundoff noise-to-signal ratio in the measurement of the signal power is derived, and computer simulations which validate the analytical results are presented. These results can be used in tradeoff studies of hardware design, such as the number of bits required at each processing stage. The results presented in this paper are currently being used in the design of a digital Doppler processor (Chi et al., 1986) for a radar scatterometer.

  3. Thermal Impact Analysis of Circulating Current in High Power Modular Online Uninterruptible Power Supplies Application

    DEFF Research Database (Denmark)

    Zhang, Chi; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2017-01-01

    In modular uninterruptible power supplies (UPSs), several DC/AC modules are required to work in parallel. This structure allows the system to be more reliable and flexible. These DC/AC modules share the same DC bus and AC critical bus. Module differences, such as filter inductor, filter capacitor......, control parameters, and so on, will make it possible for the potential zero sequence current to flow among the modules. This undesired type of circulating current will bring extra losses to the power semiconductor devices in the system, which should be paid special attention in high power application...... scenarios. In this paper, plug’n’play modules and cycle control are discussed and validated through experimental results. Moreover, potential zero sequence circulating current impact on power semiconductor devices thermal performance is also analyzed in this paper....

  4. Design of Low Power Test Pattern Generator using Low Transition LFSR for high Fault Coverage Analysis

    Directory of Open Access Journals (Sweden)

    Chethan J

    2013-08-01

    Full Text Available A low power Test Pattern Generator (TPG designed by modifying Linear Feedback Shift Register is proposed to produce low power test vectors that are deployed on Circuit under Test (CUT to slenderize thedynamic power consumption by CUT. The technique involved in generating low power test patterns is performed by increasing the correlativity between the successive vectors; the ambiguity in increasing the similarity between consecutive vectors is resolved by reducing the number of bit flips between successive test patterns. Upon deploying the low power test patterns at the inputs of CUT, slenderizes the switching activities inside CUT that in turn reduces its dynamic power consumption. The resulted low power test vectors are deployed on CUT to obtain fault coverage. The experimental results demonstrate significant power reduction by low power TPG than compared to standard LFSR.

  5. Design and analysis of an underwater inductive coupling power transfer system for autonomous underwater vehicle docking applications

    Institute of Scientific and Technical Information of China (English)

    Jian-guang SHI; De-jun LI; Can-jun YANG

    2014-01-01

    We develop a new kind of underwater inductive coupling power transfer (ICPT) system to evaluate wireless power transfer in autonomous underwater vehicle (AUV) docking applications. Parameters that determine the performance of the system are systematically analyzed through mathematical methods. A circuit simulation model and a finite element analysis (FEA) sim-ulation model are developed to study the power losses of the system, including copper loss in coils, semiconductor loss in circuits, and eddy current loss in transmission media. The characteristics of the power losses can provide guidelines to improve the effi-ciency of ICPT systems. Calculation results and simulation results are validated by relevant experiments of the prototype system. The output power of the prototype system is up to 45 W and the efficiency is up to 0.84. The preliminary results indicate that the efficiency will increase as the transmission power is raised by increasing the input voltage. When the output power reaches 500 W, the efficiency is expected to exceed 0.94. The efficiency can be further improved by choosing proper semiconductors and coils. The analysis methods prove effective in predicting the performance of similar ICPT systems and should be useful in designing new systems.

  6. Functional Level Power Analysis: An Efficient Approach for Modeling the Power Consumption of Complex Processors

    OpenAIRE

    2004-01-01

    A high-level consumption estimation methodology and its associated tool, SoftExplorer, are presented. The estimation methodology uses a functional modeling of the processor combined with a parametric model to allow the designer to estimate the power consumption when the embedded software is executed on the target. SoftExplorer uses as input the assembly code generated by the compiler; its efficiency is compared to SimplePower's approach. Results for different processors (TI C62, C67, C55 and ...

  7. Dynamic response characteristics analysis of the doubly-fed wind power system under grid voltage drop

    Science.gov (United States)

    Chen, Y.; Wang, J.; Wang, H. H.; Yang, L.; Chen, W.; Xu, Y. T.

    2016-08-01

    Double-fed induction generator (DFIG) is sensitive to the disturbances of grid, so the security and stability of the grid and the DFIG itself are under threat with the rapid increase of DFIG. Therefore, it is important to study dynamic response of the DFIG when voltage drop failure is happened in power system. In this paper, firstly, mathematical models and the control strategy about mechanical and electrical response processes is respectively introduced. Then through the analysis of response process, it is concluded that the dynamic response characteristics are related to voltage drop level, operating status of DFIG and control strategy adapted to rotor side. Last, the correctness of conclusion is validated by the simulation about mechanical and electrical response processes in different voltage levels drop and different DFIG output levels under DIgSILENT/PowerFactory software platform.

  8. Design and Analysis of Cross Flow Turbine for Micro Hydro Power Application using Sewerage Water

    Directory of Open Access Journals (Sweden)

    Muhammad Adil Khan

    2014-08-01

    Full Text Available The objective of this study endeavor is to describe the design of an environment friendly captive micro hydel power plant at the sewerage treatment plant outlet fall at Lai Nallah located in I-9 Islamabad. It will use sewerage water of CDA as discharge water to run the turbine of the micro hydel power plant to generate electricity. The important phases of the project are to carry out survey for collection of data about hydrology, quantity of flow of water, fall head, geology and design of an efficient turbine. Complete design calculations of turbine have been performed along with static and model analysis of the turbine. Key parameters to increase efficiency of cross-flow turbine are discussed.

  9. Energy Analysis of a Biomass Co-firing Based Pulverized Coal Power Generation System

    Directory of Open Access Journals (Sweden)

    Marc A. Rosen

    2012-03-01

    Full Text Available The results are reported of an energy analysis of a biomass/coal co-firing based power generation system, carried out to investigate the impacts of biomass co-firing on system performance. The power generation system is a typical pulverized coal-fired steam cycle unit, in which four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel and two coals (bituminous coal and lignite are considered. Key system performance parameters are evaluated for various fuel combinations and co-firing ratios, using a system model and numerical simulation. The results indicate that plant energy efficiency decreases with increase of biomass proportion in the fuel mixture, and that the extent of the decrease depends on specific properties of the coal and biomass types.

  10. Cost analysis of concepts for a demand oriented biogas supply for flexible power generation.

    Science.gov (United States)

    Hahn, Henning; Ganagin, Waldemar; Hartmann, Kilian; Wachendorf, Michael

    2014-10-01

    With the share of intermittent renewable energies within the electricity system rising, balancing services from dispatchable power plants are of increasing importance. Highlighting the importance of the need to keeping fuel costs for flexible power generation to a minimum, the study aims to identify favourable biogas plant configurations, supplying biogas on demand. A cost analysis of five configurations based on biogas storing and flexible biogas production concepts has been carried out. Results show that additional flexibility costs for a biogas supply of 8h per day range between 2€ and 11€MWh(-1) and for a 72h period without biogas demand from 9€ to 19€MWh(-1). While biogas storage concepts were identified as favourable short term supply configurations, flexible biogas production concepts profit from reduced storage requirements at plants with large biogas production capacities or for periods of several hours without biogas demand.

  11. Exergy Analysis of Gas Turbine – Fuel cell based combined Cycle Power Plant

    Directory of Open Access Journals (Sweden)

    M.Sreeramulu,

    2011-06-01

    Full Text Available The increase in demand for electrical energy leads to the newer power generation systems. Though it is not new, fuel cell technology is one of the promising systems for cleaner and competitive alternate power generation system. When the fuel cells are integrated with the Gas Turbines, the total thermal efficiency of the combined cycle is obtained greater than 60%. In this paper, thermodynamic analysis of SOFC-GT combined system (2.898MW has been carried out, exergy efficiency and exergy destruction of each component are calculated.The effect of compression ratio (rp, turbine inlet temperature (TIT and ambient temperature of air, on the performance of the system has been analyzed. Outcome of the system modeling reveals that SOFC andcombustion chamber are the main sources of exergy destruction. At the optimum compression ratio 9, the total thermal efficiency and exergy efficiency are found to be 63.3% and 60.85% respectively.

  12. Data analysis from monitoring of radionuclides in the nuclear power plant Temelin ecosystem area.

    Science.gov (United States)

    Thinova, Lenka; Trojek, Tomas

    2009-01-01

    Changes in the ecosystem occur naturally, however, can also be due to man's activity. The unique ecosystem monitoring based on studying contamination of the bioindicators by man-made radionuclides has been providing data from the area of nuclear power plant (NPP) Temelin (CR) using laboratory gamma spectrometry for past 8 years. The increase in radioactivity in the NPP ecosystem area resulting from its operation is evaluated through comparison with a zero level of (137)Cs mass activities and by obtained data trend analysis.

  13. Power scaling analysis of high power fiber laser employing online three-section recoating method of splice point

    Science.gov (United States)

    Huang, Zhihua; Tang, Xuan; Zhao, Pengfei; Li, Chengyu; Li, Qi; Guo, Chao; Li, Zebiao; Lin, Honghuan; Wang, Jianjun

    2016-12-01

    Thermal damage is a major limiting factor in the experimental power scaling of high power fiber lasers. A novel online three-section recoating method is proposed in this work which can remove the leaked light due to interface imperfection and improve the heat transfer of the splicing. More than 5.4~\\text{kW} pump power is injected into the gain fiber through the splice point without damage. Theoretical analysis is carried out with both of the analytical and finite element models. The theoretical results agree in temperature growth slope with the experimental results and the extrapolation implies that it is possible to inject more than 10~\\text{kW} pump power into the 30/600 YDF from the single end using this method.

  14. Design Analysis of Power Extracting Unit of an Onshore OWC Based Wave Energy Power Plant using Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Zahid Suleman

    2011-07-01

    Full Text Available This research paper describes design and analysis of power extracting unit of an onshore OWC (Oscillating Water Column based wave energy power plant of capacity about 100 kilowatts. The OWC is modeled as solid piston of a reciprocating pump. The power extracting unit is designed analytically by using the theory of reciprocating pumps and principles of fluid mechanics. Pro-E and ANSYS workbench softwares are used to verify the analytical design. The analytical results of the flow velocity in the turbine duct are compared with the simulation results. The results are found to be in good agreement with each other. The results achieved by this research would finally assist in the overall design of the power plant which is the ultimate goal of this research work.

  15. STUDY OF INFLUENCE OF WIND-POWER STATIONS ON BIRDS: ANALYSIS OF INTERNATIONAL PRACTICES

    OpenAIRE

    Gorlov P. I.; Siokhin V. D.

    2012-01-01

    The world experience of bird collisions with wind-power stations was analyzed. The detailcharacteristics of principal threats to the birds during building and exploitation of wind-power stations was done. Comparative analysis of factors caused annual birds mortality was performed. Some proposals of negative influence minimization were suggested for wind-power stations utilization.

  16. STUDY OF INFLUENCE OF WIND-POWER STATIONS ON BIRDS: ANALYSIS OF INTERNATIONAL PRACTICES

    Directory of Open Access Journals (Sweden)

    Gorlov P. I.

    2012-06-01

    Full Text Available The world experience of bird collisions with wind-power stations was analyzed. The detailcharacteristics of principal threats to the birds during building and exploitation of wind-power stations was done. Comparative analysis of factors caused annual birds mortality was performed. Some proposals of negative influence minimization were suggested for wind-power stations utilization.

  17. Restructured electric power systems analysis of electricity markets with equilibrium models

    CERN Document Server

    2010-01-01

    Electricity market deregulation is driving the power energy production from a monopolistic structure into a competitive market environment. The development of electricity markets has necessitated the need to analyze market behavior and power. Restructured Electric Power Systems reviews the latest developments in electricity market equilibrium models and discusses the application of such models in the practical analysis and assessment of electricity markets.

  18. Harmonic Stability Analysis of Inverter-Fed Power Systems Using Component Connection Method

    DEFF Research Database (Denmark)

    Wang, Yanbo; Wang, Xiongfei; Blaabjerg, Frede

    2016-01-01

    This paper presents a Component Connection Method (CCM)-based harmonic stability analysis for ac power-electronic-fed power systems. In the approach, the system is partitioned as individual components, including the controllers of DG units, LC filters, network impedances, and power loads. They ar...

  19. Power Quality Experimental Analysis on Rural Home Grid-Connected PV Systems

    Directory of Open Access Journals (Sweden)

    Rita Jorge Cerqueira Pinto

    2015-01-01

    Full Text Available Microgeneration is the small-scale generation of heat or electric power or both, by individuals or buildings to meet their own needs. Recently, microgeneration is being regarded as a means to decentralize the power production of renewable energies, reducing the impacts on the grid caused by unexpected energy demands. Given the increase in microgeneration facilities, determining the quantity of energy produced and the power quality assumes growing importance in low, medium, or high voltage facilities. This paper presents a power quality analysis of two different facilities with photovoltaic generation localized in a rural area of Portugal, describing the voltage and frequency behaviour, the harmonic contents, and the total harmonic distortion. Statistical data are presented regarding the number of voltage events and occurrence of dips and swells in both facilities as a percentage of rated voltage. We conclude that some PV systems can severely affect voltage quality, forcing the grid to work at and even above the maximum voltage standard limit.

  20. Game-theoretic control of PHEV charging with power flow analysis

    Directory of Open Access Journals (Sweden)

    Yuan Liu

    2016-03-01

    Full Text Available Due to an ever-increasing market penetration of plug-in hybrid electric vehicles (PHEVs, the charging demand is expected to become a main determinant of the load in future distribution systems. In this paper, we investigate the problem of controlling in-home charging of PHEVs to accomplish peak load shifting while maximizing the revenue of the distribution service provider (DSP and PHEV owners. A leader-follower game model is proposed to characterize the preference and revenue expectation of PHEV owners and DSP, respectively. The follower (PHEV owner decides when to start charging based on the pricing schedule provided by the leader (DSP. The DSP can incentivize the charging of PHEV owners to avoid system peak load. The costs associated with power distribution, line loss, and voltage regulation are incorporated in the game model via power flow analysis. Based on a linear approximation of the power flow equations, the solution of sub-game perfect Nash equilibrium (SPNE is obtained. A case study is performed based on the IEEE 13-bus test feeder and realistic PHEV charging statistics, and the results demonstrate that our proposed PHEV charging control scheme can significantly improve the power quality in distribution systems by reducing the peak load and voltage fluctuations.

  1. A comparative life cycle analysis of low power PV lighting products for rural areas in South East Asia

    NARCIS (Netherlands)

    Durlinger, B.P.J.; Reinders, A.H.M.E.; Toxopeus, M.E.

    2012-01-01

    This paper evaluates the environmental effects of low power PV lighting products, which are increasingly used in rural areas in South East Asia, by means of a life cycle analysis (LCA). The main goals of the project are to determine (1) the environmental impacts, (2) which parts are contributing to

  2. Detection of Wind Turbine Power Performance Abnormalities Using Eigenvalue Analysis

    DEFF Research Database (Denmark)

    Skrimpas, Georgios Alexandros; Sweeney, Christian Walsted; Marhadi, Kun Saptohartyadi

    2014-01-01

    in order to achieve better resolution and thus identify the most proba- ble root cause of the power deviation. An important aspect of the proposed technique is its independence of the power curve provided by the turbine manufacturer. It is shown that by detecting any changes of the two eigenvalues trends...

  3. Numerical analysis of power system transients and dynamics

    CERN Document Server

    Ametani, Akihiro

    2015-01-01

    This book describes the three major power system transient and dynamics simulation tools based on a circuit-theory based approach which are most widely used all over the world (EMTP-ATP, EMTP-RV and EMTDC/PSCAD), together with other powerful simulation tools such as XTAP.

  4. Power Analysis for Complex Mediational Designs Using Monte Carlo Methods

    Science.gov (United States)

    Thoemmes, Felix; MacKinnon, David P.; Reiser, Mark R.

    2010-01-01

    Applied researchers often include mediation effects in applications of advanced methods such as latent variable models and linear growth curve models. Guidance on how to estimate statistical power to detect mediation for these models has not yet been addressed in the literature. We describe a general framework for power analyses for complex…

  5. Power consumption analysis of constant bit rate video transmission over 3G networks

    DEFF Research Database (Denmark)

    Ukhanova, Ann; Belyaev, Evgeny; Wang, Le

    2012-01-01

    for the 3GPP transition state machine that allows to decrease power consumption on a mobile device taking signaling traffic, buffer size and latency restrictions into account. Furthermore, we discuss the gain in power consumption vs. PSNR for transmitted video and show the possibility of performing power......This paper presents an analysis of the power consumption of video data transmission with constant bit rate over 3G mobile wireless networks. The work includes the description of the radio resource control transition state machine in 3G networks, followed by a detailed power consumption analysis...... consumption management based on the requirements for the video quality....

  6. Sharing wind power forecasts in electricity markets: A numerical analysis

    DEFF Research Database (Denmark)

    Exizidis, Lazaros; Pinson, Pierre; Kazempour, Jalal

    2016-01-01

    more informed day-ahead schedules, which reduces the need for balancing resources in real-time operation. This paper numerically evaluates the potential value of sharing forecasts for the whole system in terms of system cost reduction. Besides, its impact on each market player’s profit is analyzed......In an electricity pool with significant share of wind power, all generators including conventional and wind power units are generally scheduled in a day-ahead market based on wind power forecasts. Then, a real-time market is cleared given the updated wind power forecast and fixed day...... flexible resources to the system. In this paper, we address another potential solution based on information sharing in which market players share their own wind power forecasts with others in day-ahead market. This solution may improve the functioning of sequential market-clearing process through making...

  7. Analysis of power supply circuits for electroluminescent panels

    Science.gov (United States)

    Drumea, Andrei; Dobre, Robert Alexandru

    2016-12-01

    The electroluminescent panel is a light emitting device that requires for normal operations alternative voltages with peak to peak amplitudes in 100V… 300V range and frequencies in 100Hz … 2 kHz range. Its advantages, when compared with standard light sources like incandescent lamps, gas-discharge lamps or light emitting diodes (LEDs), are lower power consumption, flexible substrate and uniform light without observable luminous points. One disadvantage of electroluminescent panels is the complex power supply required to drive them, but the continuous improvement in passive and active integrated devices for switched mode power supplies will eventually solve this issue. The present paper studies different topologies for these power supplies and the effect of the electric parameters like the amplitude, frequency, waveform of the supplying voltage on the light emission and on power consumption for electroluminescent panels with different size and colors.

  8. Performance Analysis of Supercritical Binary Geothermal Power Plants

    Directory of Open Access Journals (Sweden)

    Ahmet Dagdas

    2015-01-01

    Full Text Available It is possible to generate electricity by utilizing medium-temperature geothermal sources in various closed cycles. These geothermal power plants are very important and valuable as they utilize the sources which have low exergy. In recent years, medium-temperature sources that are around 150°C are used widely for electricity generation. In this study, performance of a supercritical binary power plant, that uses such a geothermal source, is analyzed to find the optimum turbine inlet pressure that maximizes power generation. In this power plant different working fluids are analyzed to find the appropriate fluid that maximizes power generation and efficiency. The observed working fluids are R134a, isobutane, R404a, n-Butane, and R152a. The performance of the plant is calculated with these fluids separately and it is found that the best fluid for performance is R152a for pure fluid and R404a for mixture fluid.

  9. The characteristic analysis of the solar energy photovoltaic power generation system

    Science.gov (United States)

    Liu, B.; Li, K.; Niu, D. D.; Jin, Y. A.; Liu, Y.

    2017-01-01

    Solar energy is an inexhaustible, clean, renewable energy source. Photovoltaic cells are a key component in solar power generation, so thorough research on output characteristics is of far-reaching importance. In this paper, an illumination model and a photovoltaic power station output power model were established, and simulation analysis was conducted using Matlab and other software. The analysis evaluated the condition of solar energy resources in the Baicheng region in the western part of Jilin province, China. The characteristic curve of the power output from a photovoltaic power station was obtained by simulation calculation. It was shown that the monthly average output power of the photovoltaic power station is affected by seasonal changes; the output power is higher in summer and autumn, and lower in spring and winter.

  10. Langevin power curve analysis for numerical WEC models with new insights on high frequency power performance

    CERN Document Server

    Mücke, Tanja A; Milan, Patrick; Peinke, Joachim

    2015-01-01

    Based on the Langevin equation it has been proposed to obtain power curves for wind turbines from high frequency data of wind speed measurements u(t) and power output P (t). The two parts of the Langevin approach, power curve and drift field, give a comprehensive description of the conversion dynamic over the whole operating range of the wind turbine. The method deals with high frequent data instead of 10 min means. It is therefore possible to gain a reliable power curve already from a small amount of data per wind speed. Furthermore, the method is able to visualize multiple fixed points, which is e.g. characteristic for the transition from partial to full load or in case the conversion process deviates from the standard procedures. In order to gain a deeper knowledge it is essential that the method works not only for measured data but also for numerical wind turbine models and synthetic wind fields. Here, we characterize the dynamics of a detailed numerical wind turbine model and calculate the Langevin power...

  11. Mathematical Analysis of Space Radiator Segmenting for Increased Reliability and Reduced Mass

    Science.gov (United States)

    Juhasz, Albert J.

    2001-01-01

    Spacecraft for long duration deep space missions will need to be designed to survive micrometeoroid bombardment of their surfaces some of which may actually be punctured. To avoid loss of the entire mission the damage due to such punctures must be limited to small, localized areas. This is especially true for power system radiators, which necessarily feature large surface areas to reject heat at relatively low temperature to the space environment by thermal radiation. It may be intuitively obvious that if a space radiator is composed of a large number of independently operating segments, such as heat pipes, a random micrometeoroid puncture will result only in the loss of the punctured segment, and not the entire radiator. Due to the redundancy achieved by independently operating segments, the wall thickness and consequently the weight of such segments can be drastically reduced. Probability theory is used to estimate the magnitude of such weight reductions as the number of segments is increased. An analysis of relevant parameter values required for minimum mass segmented radiators is also included.

  12. Technico-economical analysis of a hybrid wave power-air compression storage system

    OpenAIRE

    Hernandez-Torres, David; Bridier, Laurent; David, Mathieu; Lauret, Philippe; Ardiale, Thomas

    2015-01-01

    International audience; This paper presents a technico-economical analysis of a Pelamis wave power generator coupled with a proposed air compression storage system. Ocean wave measurements and forecasts are used from a site near the city of Saint-Pierre in Réunion island, France. The insular context requires both smoothing and forecast of the output power from the wave power system. The storage system is a solution to meet this requirement. Several power network services are defined by the ut...

  13. Gasification technology increases the efficiency of power plants. Automation solution controls processses; Vergasungstechnologie steigert Effizienz von Kraftwerken. Automatisierungsloesung steuert Prozesse

    Energy Technology Data Exchange (ETDEWEB)

    Laufkoetter, Silke

    2013-04-15

    More electric power and heat from waste and biomass - this enables innovative technologies which were developed by Metso (Helsinki, Finland). The plant installed by Metso in Lathi (Finland) is a milestone in the technology of the waste incineration: Never before, a power plant has gasified waste materials in such an order of magnitude. In Pori (Finland) biomass was gasified. The automation solution Metso DNA was used in both power plants in order to control the demanding processes.

  14. Prospective Analysis of Life-Cycle Indicators through Endogenous Integration into a National Power Generation Model

    Directory of Open Access Journals (Sweden)

    Diego García-Gusano

    2016-11-01

    Full Text Available Given the increasing importance of sustainability aspects in national energy plans, this article deals with the prospective analysis of life-cycle indicators of the power generation sector through the case study of Spain. A technology-rich, optimisation-based model for power generation in Spain is developed and provided with endogenous life-cycle indicators (climate change, resources, and human health to assess their evolution to 2050. Prospective performance indicators are analysed under two energy scenarios: a business-as-usual one, and an alternative scenario favouring the role of carbon dioxide capture in the electricity production mix by 2050. Life-cycle impacts are found to decrease substantially when existing fossil technologies disappear in the mix (especially coal thermal power plants. In the long term, the relatively high presence of natural gas arises as the main source of impact. When the installation of new fossil options without CO2 capture is forbidden by 2030, both renewable technologies and—to a lesser extent—fossil technologies with CO2 capture are found to increase their contribution to electricity production. The endogenous integration of life-cycle indicators into energy models proves to boost the usefulness of both life cycle assessment and energy systems modelling in order to support decision- and policy-making.

  15. A critical discussion of null hypothesis significance testing and statistical power analysis within psychological research

    DEFF Research Database (Denmark)

    Jones, Allan; Sommerlund, Bo

    2007-01-01

    The uses of null hypothesis significance testing (NHST) and statistical power analysis within psychological research are critically discussed. The article looks at the problems of relying solely on NHST when dealing with small and large sample sizes. The use of power-analysis in estimating...... the potential error introduced by small and large samples is advocated. Power analysis is not recommended as a replacement to NHST but as an additional source of information about the phenomena under investigation. Moreover, the importance of conceptual analysis in relation to statistical analysis of hypothesis...

  16. Leakage Power Reduction and Analysis of CMOS Sequential Circuits

    Directory of Open Access Journals (Sweden)

    M. Janaki Rani

    2012-02-01

    Full Text Available A significant portion of the total power consumption in high performance digital circuits in deep sub micron regime is mainly due to leakage power. Leakage is the only source of power consumption in an idle circuit. Therefore it is important to reduce leakage power in portable systems. In this paper two techniques such as transistor stacking and self-adjustable voltage level circuit for reducing leakage power in sequential circuits are proposed. This work analyses the power and delay of three different types of D flip-flops using pass transistors, transmission gates and gate diffusion input gates. . All the circuits are simulated with and without the application of leakage reduction techniques. Simulation results show that the proposed pass transistor based D flip-flop using self-adjustable voltage level circuit has the least leakage power dissipation of 9.13nW with a delay of 77 nS. The circuits are simulated with MOSFET models of level 54 using HSPICE in 90 nm process technology.

  17. EEG Power Spectrum Analysis in Children with ADHD

    Science.gov (United States)

    Kamida, Akira; Shimabayashi, Kenta; Oguri, Masayoshi; Takamori, Toshihiro; Ueda, Naoyuki; Koyanagi, Yuki; Sannomiya, Naoko; Nagira, Haruki; Ikunishi, Saeko; Hattori, Yuiko; Sato, Kengo; Fukuda, Chisako; Hirooka, Yasuaki; Maegaki, Yoshihiro

    2016-01-01

    Background Attention deficit disorder/hyperactivity disorder (ADHD) is a pathological condition that is not fully understood. In this study, we investigated electroencephalographic (EEG) power differences between children with ADHD and healthy control children. Methods EEGs were recorded as part of routine medical care received by 80 children with ADHD aged 4–15 years at the Department of Pediatric Neurology in Tottori University Hospital. Additionally, we recorded in 59 control children aged 4–15 years after obtaining informed consent. Specifically, awake EEG signals were recorded from each child using the international 10–20 system, and we used ten 3-s epochs on the EEG power spectrum to calculate the powers of individual EEG frequency bands. Results The powers of different EEG bands were significantly higher in the frontal brain region of those in the ADHD group compared with the control group. In addition, the power of the beta band in the ADHD group was significantly higher in all brain regions, except for the occipital region, compared with control children. With regard to developmental changes, the power of the alpha band in the occipital region showed an age-dependent decrease in both groups, with slightly lower power in the ADHD group. Additionally, the intergroup difference decreased in children aged 11 years or older. As with the alpha band in the occipital region, the beta band in the frontal region showed an age-dependent decrease in both groups. Unlike the alpha band, the power of the beta band was higher in the ADHD group than in the control group for children of all ages. Conclusion The observed intergroup differences in EEG power may provide insight into the brain function of children with ADHD. PMID:27493489

  18. Increased Power in Sediment Microbial Fuel Cell: Facilitated Mass Transfer via a Water-Layer Anode Embedded in Sediment.

    Directory of Open Access Journals (Sweden)

    Yoo Seok Lee

    Full Text Available We report a methodology for enhancing the mass transfer at the anode electrode of sediment microbial fuel cells (SMFCs, by employing a fabric baffle to create a separate water-layer for installing the anode electrode in sediment. The maximum power in an SMFC with the anode installed in the separate water-layer (SMFC-wFB was improved by factor of 6.6 compared to an SMFC having the anode embedded in the sediment (SMFC-woFB. The maximum current density in the SMFC-wFB was also 3.9 times higher (220.46 mA/m2 than for the SMFC-woFB. We found that the increased performance in the SMFC-wFB was due to the improved mass transfer rate of organic matter obtained by employing the water-layer during anode installation in the sediment layer. Acetate injection tests revealed that the SMFC-wFB could be applied to natural water bodies in which there is frequent organic contamination, based on the acetate flux from the cathode to the anode.

  19. Reliability modeling and analysis of smart power systems

    CERN Document Server

    Karki, Rajesh; Verma, Ajit Kumar

    2014-01-01

    The volume presents the research work in understanding, modeling and quantifying the risks associated with different ways of implementing smart grid technology in power systems in order to plan and operate a modern power system with an acceptable level of reliability. Power systems throughout the world are undergoing significant changes creating new challenges to system planning and operation in order to provide reliable and efficient use of electrical energy. The appropriate use of smart grid technology is an important drive in mitigating these problems and requires considerable research acti

  20. Analysis of power demand signal in laboratory rotary mixer

    Directory of Open Access Journals (Sweden)

    K. Smyksy

    2010-04-01

    Full Text Available The paper summarises the power measurement data for the main assemblies in a prototype turbine mixers for laboratory applications. Of particular interest are power demand signals in the paddle stirrer and the rotor. Tests were performed for the variable moisture content of the moulding sand containing bentonite. The process is described as dynamic and considered from the standpoint of automatics. Potential applications of the power demand signal are investigated in the context of the study of dynamics of the mixing processes, in terms of control of the water feeding to the moulding sand and for the purpose of evaluating the energy consumption.

  1. Analysis and Experimental Evaluation of Power Line Transmission Parameters for Power Line Communication

    Science.gov (United States)

    Mlynek, P.; Misurec, J.; Koutny, M.; Fujdiak, R.; Jedlicka, T.

    2015-04-01

    The article describes a way of evaluating the power line channel frequency response and input impedance by means of the linear time-invariant (LTI) power line generator. Two possible methods are introduced for the calculation of primary parameters: the first method depends on the physical realization and physical dimension of the cable, and the second method is derived from the data provided by typical electrical cable manufacturers. Based on these methods, a comparison of transfer functions was made. This is followed by measurement evaluation and numerical verification on a simple topology

  2. Loss Performance Analysis of an Isolated Power Supply for Ultrafast Tracking Converters

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the loss performance analysis of an isolated power supply that is designed for ultra-fast tracking converters. The results of the analysis provide insights into the operation of the proposed power supply, how each physical component contributes to the total loss, and how its e...

  3. Power loss analysis of n-PASHA cells validated by 2D simulations

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, G.J.M.; Gutjahr, A.; Burgers, A.R.; Saynova, D.S.; Cesar, I.; Romijn, I.G.

    2013-10-15

    To reach >21% efficiency for the n-Pasha (passivated all sides H-pattern) cell of ECN, reliable power-loss analyses are essential. A power-loss analysis is presented that is based on experimental data but validated and completed by 2D simulations. The analysis is used to identify the key factors that will contribute most to achieving >21% efficiency.

  4. On Power Relations in The Little Foxes from the Perspective of Turn-tak-ing Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-hua

    2015-01-01

    This paper focuses on discussing the power relations among the Hubbards from the perspective of turn-taking analysis. In it, a lot of work about the quantitative turn-taking analysis has been done. And the mentioned data reflects that there is a close relationship between power and turn-taking.

  5. Analysis of the influences of grid-connected PV power system on distribution grids

    Directory of Open Access Journals (Sweden)

    Dumitru Popandron

    2013-12-01

    Full Text Available This paper presents the analysis of producing an electric power of 2.8 MW using a solar photovoltaic plant. The PV will be grid connected to the distribution network. The study is focused on the influences of connecting to the grid of a photovoltaic system, using modern software for analysis, modeling and simulation in power systems.

  6. Use of fuzzy techniques for analysis of dynamic loads in power systems

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Presents the use of fuzzy techniques for analysis of dynamic load characteristics of power systems to identify the voltage stability (collapse) of a weak bus and concludes from the consistent results obtained that this is a useful tool for analysis of load charactersitics of sophiscated power systems and their components.

  7. Comparative analysis of cooling systems for energy equipment of combined heat and power plants and nuclear power plants

    Science.gov (United States)

    Reutov, B. F.; Lazarev, M. V.; Ermakova, S. V.; Zisman, S. L.; Kaplanovich, L. S.; Svetushkov, V. V.

    2016-07-01

    In the 20th century, the thermal power engineering in this country was oriented toward oncethrough cooling systems. More than 50% of the CHPP and NPP capacities with once-through cooling systems put into operation before the 1990s were large-scale water consumers but with minimum irretrievable water consumption. In 1995, the Water Code of the Russian Federation was adopted in which restrictions on application of once-through cooling systems for newly designed combined heat and power plants (CHPPs) were introduced for the first time. A ban on application of once-through systems was imposed by the current Water Code of the Russian Federation (Federal law no. 74-FZ, Art. 60 Cl. 4) not only for new CHPPs but also for those to be modified. Clause 4 of Article 60 of the Water Code of the Russian Federation contravenes law no. 7-FZ "On Protection of the Environment" that has priority significance, since the water environment is only part of the natural environment and those articles of the Water Code of the Russian Federation that are related directly to electric power engineering, viz., Articles 46 and 62. In recent decades, the search for means to increase revenue charges and the economic pressure on the thermal power industry caused introduction by law of charges for use of water by cooling systems irrespective of the latter's impact on the water quality of the source, the environment, the economic efficiency of the power production, and the living conditions of the people. The long-range annual increase in the water use charges forces the power generating companies to switch transfer once-through service water supply installations to recirculating water supply systems and once-through-recirculating systems with multiple reuse of warm water, which drastically reduces the technical, economic, and ecological characteristic of the power plant operation and also results in increasing power rates for the population. This work comprehensively substantiates the demands of

  8. Performance Analysis of XCPC Powered Solar Cooling Demonstration Project

    Science.gov (United States)

    Widyolar, Bennett K.

    A solar thermal cooling system using novel non-tracking External Compound Parabolic Concentrators (XCPC) has been built at the University of California, Merced and operated for two cooling seasons. Its performance in providing power for space cooling has been analyzed. This solar cooling system is comprised of 53.3 m2 of XCPC trough collectors which are used to power a 23 kW double effect (LiBr) absorption chiller. This is the first system that combines both XCPC and absorption chilling technologies. Performance of the system was measured in both sunny and cloudy conditions, with both clean and dirty collectors. It was found that these collectors are well suited at providing thermal power to drive absorption cooling systems and that both the coinciding of available thermal power with cooling demand and the simplicity of the XCPC collectors compared to other solar thermal collectors makes them a highly attractive candidate for cooling projects.

  9. Off-grid power quality: Impacts, analysis and solutions

    Science.gov (United States)

    Gautam, Arjun

    Good power quality is a critical factor for the reliable operation of electrical loads in a power system. However, the current drawn by many electronic devices and non-linear loads are non-sinusoidal, which can result in a poor power quality, particularly in off-grid power systems. Poor power quality is characterized by electrical disturbances such as transients, sags, swells, harmonics and even interruptions in the power supply. Off-grid power systems worldwide struggle with system failures and equipment damage due to poor power quality. To better understand off-grid system failures and equipment damage issues, the current and voltage characteristics of a number of electrical devices in two off-grid homes, one using a pure sine wave inverter and the other using a modified sine wave inverter, were recorded with a Fluke 43B power quality analyzer, and the devices' impact on the power quality of the off-grid systems was analyzed. The off-grid power quality data were then compared with data from a grid-connected apartment, to help identify the issues that were specific to off-grid systems. The MATLAB/Simulink software was used to model and analyze power quality for additional configurations of the two off-grid systems mentioned above. Strategies to mitigate the worst power quality issues were selected based upon their function and cost, and a few were tested in an off-grid system. Selection of an inverter was found to be important because not all devices are supported by each type of inverter. For example, the refrigerator in the off-grid home with a modified sine wave inverter produced a significant amount of current and voltage harmonics far above standards. In fact, this type of inverter does not support a number of sensitive devices including motors, refrigerators, microwave ovens, fluorescent lights, battery chargers etc. The major issues for the degradation of power quality in the off-grid system using a pure sine wave inverter were the current harmonics

  10. Total loss of AC power analysis for EPR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Darnowski, Piotr, E-mail: piotr.darnowski@itc.pw.edu.pl [Warsaw University of Technology, Institute of Heat Engineering, Nowowiejska 21/25, 00-665 Warsaw (Poland); Skrzypek, Eleonora, E-mail: eleonora.skrzypek@ncbj.gov.pl [Warsaw University of Technology, Institute of Heat Engineering, Nowowiejska 21/25, 00-665 Warsaw (Poland); National Centre for Nuclear Research (NCBJ), A. Sołtana 7, 05-400 Otwock-Świerk (Poland); Mazgaj, Piotr, E-mail: piotr.mazgaj@itc.pw.edu.pl [Warsaw University of Technology, Institute of Heat Engineering, Nowowiejska 21/25, 00-665 Warsaw (Poland); Świrski, Konrad [Warsaw University of Technology, Institute of Heat Engineering, Nowowiejska 21/25, 00-665 Warsaw (Poland); Gandrille, Pascal [AREVA NP SAS, Tour AREVA, 1 place Jean Millier, 92084 Paris La Défense (France)

    2015-08-15

    Highlights: • Total loss of AC power (Station Blackout) was simulated for the EPR reactor model. • In-vessel phase of the accident is under consideration. • Comparison of MELCOR and MAAP results is presented. • MELCOR and MAAP results are comparable. - Abstract: In this paper the results of severe accident simulations for the EPR reactor in the case of loss of offsite power combined with total failure of all diesel generators (total loss of AC power) are presented. Calculations were performed with MELCOR 2.1 computer code for in-vessel phase of the accident. In this scenario, the unavailability of all offsite and onsite power sources and the lack of cooling leads directly to core degradation, material relocation to the lower plenum and rupture of the reactor pressure vessel. MELCOR results were compared qualitatively and quantitatively with MAAP4 code results and show a good agreement.

  11. A Comparative Performance Analysis of Low Power Bypassing Array Multipliers

    Directory of Open Access Journals (Sweden)

    Nirlakalla Ravi

    2013-07-01

    Full Text Available Low power design of VLSI circuits has been identified as vital technology in battery powered portable electronic devices and signal processing applications such as Digital Signal Processors (DSP. Multiplier has an important role in the DSPs. Without degrading the performance of the processor, low power parallel multipliers are needed to be design. Bypassing is the widely used technique in the DSPs when the input operand of the multiplier is zero. A Row based Bypassing Multiplier with compressor at the final addition of the ripple carry adder (RCA is designed to focus on low power and high speed. The proposed bypassing multiplier with compressor shows high performance and energy efficiency than Kuo multiplier with Carry Save Adder (CSA at the final RCA.

  12. Modeling, analysis and control of fuel cell hybrid power systems

    Science.gov (United States)

    Suh, Kyung Won

    Transient performance is a key characteristic of fuel cells, that is sometimes more critical than efficiency, due to the importance of accepting unpredictable electric loads. To fulfill the transient requirement in vehicle propulsion and portable fuel cell applications, a fuel cell stack is typically coupled with a battery through a DC/DC converter to form a hybrid power system. Although many power management strategies already exist, they all rely on low level controllers that realize the power split. In this dissertation we design controllers that realize various power split strategies by directly manipulating physical actuators (low level commands). We maintain the causality of the electric dynamics (voltage and current) and investigate how the electric architecture affects the hybridization level and the power management. We first establish the performance limitations associated with a stand-alone and power-autonomous fuel cell system that is not supplemented by an additional energy storage and powers all its auxiliary components by itself. Specifically, we examine the transient performance in fuel cell power delivery as it is limited by the air supplied by a compressor driven by the fuel cell itself. The performance limitations arise from the intrinsic coupling in the fluid and electrical domain between the compressor and the fuel cell stack. Feedforward and feedback control strategies are used to demonstrate these limitations analytically and with simulations. Experimental tests on a small commercial fuel cell auxiliary power unit (APU) confirm the dynamics and the identified limitations. The dynamics associated with the integration of a fuel cell system and a DC/DC converter is then investigated. Decentralized and fully centralized (using linear quadratic techniques) controllers are designed to regulate the power system voltage and to prevent fuel cell oxygen starvation. Regulating these two performance variables is a difficult task and requires a compromise

  13. The Power Card Strategy: Strength-Based Intervention to Increase Direction Following of Children with Autism Spectrum Disorder

    Science.gov (United States)

    Campbell, Abbi; Tincani, Matt

    2011-01-01

    The Power Card strategy is a strength-based intervention to promote social skills of children with autism spectrum disorders (ASD) by capitalizing on their special interests. Although preliminary studies have shown that the Power Card strategy is a promising approach to teach social skills, additional research is needed. The purpose of this study…

  14. Modular high voltage power supply for chemical analysis

    Science.gov (United States)

    Stamps, James F.; Yee, Daniel D.

    2008-07-15

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  15. Electrical Power Analysis Using the Scattering Bond Graph

    Directory of Open Access Journals (Sweden)

    Roberto Tapia-Sánchez

    2015-01-01

    Full Text Available The perspective of the well known concept of active and reactive power in electrical systems is addressed in this paper. This concept is presented from the point of view of the bond graph methodology. The scattering matrix concept is used in order to deal with these formulations. The concept of active and reactive power is presented with some examples derived from single-phase AC circuits. The formulations and simulations of these circuits are presented.

  16. Electric Power Load Analysis (EPLA) for Surface Ships

    Science.gov (United States)

    2012-09-17

    ESM can be based on a host of technologies to include batteries, flywheels , and ultra-capacitors. Energy storage can be provided for use in a...electrical generation, energy storage , and power conversion components and equipment and current requirements for electrical distribution equipment and...Demand factor 4 3.7 Demand power 4 3.8 Electric and propulsion plant concept of operations 4 3.9 Emergency ship control 4 3.10 Energy storage

  17. Four-level time decomposition quasi-static power flow and successive disturbances analysis. [Power system disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, S.M. (Nikola Tesla Inst., Belgrade (YU))

    1990-01-01

    This paper presents a model and an appropriate numerical procedure for a four-level time decomposition quasi-static power flow and successive disturbances analysis of power systems. The analysis consists of the sequential computation of the zero, primary, secondary and tertiary quasi-static states and of the estimation of successive structural disturbances during the 1200 s dynamics after a structural disturbance. The model is developed by detailed inspection of the time decomposition characteristics of automatic protection and control devices. Adequate speed of the numerical procedure is attained by a specific application of the inversion matrix lemma and the decoupled model constant coefficient matrices. The four-level time decomposition quasi-static method is intended for security and emergency analysis. (author).

  18. Stochastic Drought Risk Analysis and Projection Methods For Thermoelectric Power Systems

    Science.gov (United States)

    Bekera, Behailu Belamo

    Combined effects of socio-economic, environmental, technological and political factors impact fresh cooling water availability, which is among the most important elements of thermoelectric power plant site selection and evaluation criteria. With increased variability and changes in hydrologic statistical stationarity, one concern is the increased occurrence of extreme drought events that may be attributable to climatic changes. As hydrological systems are altered, operators of thermoelectric power plants need to ensure a reliable supply of water for cooling and generation requirements. The effects of climate change are expected to influence hydrological systems at multiple scales, possibly leading to reduced efficiency of thermoelectric power plants. This study models and analyzes drought characteristics from a thermoelectric systems operational and regulation perspective. A systematic approach to characterize a stream environment in relation to extreme drought occurrence, duration and deficit-volume is proposed and demonstrated. More specifically, the objective of this research is to propose a stochastic water supply risk analysis and projection methods from thermoelectric power systems operation and management perspectives. The study defines thermoelectric drought as a shortage of cooling water due to stressed supply or beyond operable water temperature limits for an extended period of time requiring power plants to reduce production or completely shut down. It presents a thermoelectric drought risk characterization framework that considers heat content and water quantity facets of adequate water availability for uninterrupted operation of such plants and safety of its surroundings. In addition, it outlines mechanisms to identify rate of occurrences of the said droughts and stochastically quantify subsequent potential losses to the sector. This mechanism is enabled through a model based on compound Nonhomogeneous Poisson Process. This study also demonstrates how

  19. Reliability and statistical power analysis of cortical and subcortical FreeSurfer metrics in a large sample of healthy elderly.

    Science.gov (United States)

    Liem, Franziskus; Mérillat, Susan; Bezzola, Ladina; Hirsiger, Sarah; Philipp, Michel; Madhyastha, Tara; Jäncke, Lutz

    2015-03-01

    FreeSurfer is a tool to quantify cortical and subcortical brain anatomy automatically and noninvasively. Previous studies have reported reliability and statistical power analyses in relatively small samples or only selected one aspect of brain anatomy. Here, we investigated reliability and statistical power of cortical thickness, surface area, volume, and the volume of subcortical structures in a large sample (N=189) of healthy elderly subjects (64+ years). Reliability (intraclass correlation coefficient) of cortical and subcortical parameters is generally high (cortical: ICCs>0.87, subcortical: ICCs>0.95). Surface-based smoothing increases reliability of cortical thickness maps, while it decreases reliability of cortical surface area and volume. Nevertheless, statistical power of all measures benefits from smoothing. When aiming to detect a 10% difference between groups, the number of subjects required to test effects with sufficient power over the entire cortex varies between cortical measures (cortical thickness: N=39, surface area: N=21, volume: N=81; 10mm smoothing, power=0.8, α=0.05). For subcortical regions this number is between 16 and 76 subjects, depending on the region. We also demonstrate the advantage of within-subject designs over between-subject designs. Furthermore, we publicly provide a tool that allows researchers to perform a priori power analysis and sensitivity analysis to help evaluate previously published studies and to design future studies with sufficient statistical power.

  20. Analysis of the evaporative towers cooling system of a coal-fired power plant

    Directory of Open Access Journals (Sweden)

    Laković Mirjana S.

    2012-01-01

    Full Text Available The paper presents a theoretical analysis of the cooling system of a 110 MW coal-fired power plant located in central Serbia, where eight evaporative towers cool down the plant. An updated research on the evaporative tower cooling system has been carried out to show the theoretical analysis of the tower heat and mass balance, taking into account the sensible and latent heat exchanged during the processes which occur inside these towers. Power plants which are using wet cooling towers for cooling condenser cooling water have higher design temperature of cooling water, thus the designed condensing pressure is higher compared to plants with a once-through cooling system. Daily and seasonal changes further deteriorate energy efficiency of these plants, so it can be concluded that these plants have up to 5% less efficiency compared to systems with once-through cooling. The whole analysis permitted to evaluate the optimal conditions, as far as the operation of the towers is concerned, and to suggest an improvement of the plant. Since plant energy efficiency improvement has become a quite common issue today, the evaluation of the cooling system operation was conducted under the hypothesis of an increase in the plant overall energy efficiency due to low cost improvement in cooling tower system.

  1. Analysis of 12 electric power system outages/disturbances impacting the Florida Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-01

    Between January 3 and August 3, 1979, there were 12 occasions on which electric power was curtailed or public appeals were made to customers to reduce their load in Peninsular Florida due to bulk electric power supply problems. The Economic Regulatory Administration (ERA) of the US DOE, pursuant to its electric power supply adequacy and reliability responsibilities, initiated a twofold analysis of the bulk power supply situation in Florida. The first phase of the analysis evaluated the technical and engineering aspects of the overall Florida bulk power supply system with special attention given to the City of Jacksonville's electric system. The second phase evaluated the socioeconomic impacts of the bulk power supply outages on residential customers in Jacksonville. The 12 disturbances are described and a comparative analysis of the causes is presented. (LCL)

  2. Increasing ankle push-off work with a powered prosthesis does not necessarily reduce metabolic rate for transtibial amputees.

    Science.gov (United States)

    Quesada, Roberto E; Caputo, Joshua M; Collins, Steven H

    2016-10-03

    Amputees using passive ankle-foot prostheses tend to expend more metabolic energy during walking than non-amputees, and reducing this cost has been a central motivation for the development of active ankle-foot prostheses. Increased push-off work at the end of stance has been proposed as a way to reduce metabolic energy use, but the effects of push-off work have not been tested in isolation. In this experiment, participants with unilateral transtibial amputation (N=6) walked on a treadmill at a constant speed while wearing a powered prosthesis emulator. The prosthesis delivered different levels of ankle push-off work across conditions, ranging from the value for passive prostheses to double the value for non-amputee walking, while all other prosthesis mechanics were held constant. Participants completed six acclimation sessions prior to a data collection in which metabolic rate, kinematics, kinetics, muscle activity and user satisfaction were recorded. Metabolic rate was not affected by net prosthesis work rate (p=0.5; R(2)=0.007). Metabolic rate, gait mechanics and muscle activity varied widely across participants, but no participant had lower metabolic rate with higher levels of push-off work. User satisfaction was affected by push-off work (p=0.002), with participants preferring values of ankle push-off slightly higher than in non-amputee walking, possibly indicating other benefits. Restoring or augmenting ankle push-off work is not sufficient to improve energy economy for lower-limb amputees. Additional necessary conditions might include alternate timing or control, individualized tuning, or particular subject characteristics.

  3. CFD analysis of horizontal axis wind turbine blade for optimum value of power

    Energy Technology Data Exchange (ETDEWEB)

    Chandrala, Monir; Choubey, Abhishek; Gupta, Bharat [Department of Mechanical Engineering, Oriental Institute of Science and Technology, Bhopal (India)

    2013-07-01

    With the shortage of fossil fuels, alternative energy has been thrust into the national spotlight as a major necessity in order to keep up with the increasing energy demands of the world. Wind energy has been proven one of the most viable sources of renewable energy. A wind turbine is a rotary device that extracts energy from the wind. Rotor blade is a key element in a wind turbine generator system to convert wind energy into mechanical energy. In this paper rotor blade is made up of single airfoil NACA 0018. The CFD analysis of NACA 0018 airfoil is carried out at various blade angles at 32 m/s wind speed. The analysis showed that blade angle of 10 gives optimum power. The pressure and velocity distributions are plotted. These results are compared with wind tunnel experiment values.

  4. CFD analysis of horizontal axis wind turbine blade for optimum value of power

    Directory of Open Access Journals (Sweden)

    Monir Chandrala, Abhishek Choubey, Bharat Gupta

    2013-01-01

    Full Text Available With the shortage of fossil fuels, alternative energy has been thrust into the national spotlight as a major necessity in order to keep up with the increasing energy demands of the world. Wind energy has been proven one of the most viable sources of renewable energy. A wind turbine is a rotary device that extracts energy from the wind. Rotor blade is a key element in a wind turbine generator system to convert wind energy into mechanical energy. In this paper rotor blade is made up of single airfoil NACA 0018. The CFD analysis of NACA 0018 airfoil is carried out at various blade angles at 32 m/s wind speed. The analysis showed that blade angle 10º gives optimum power. The pressure and velocity distributions are plotted. These results are compared with wind tunnel experiment values.

  5. Non Linear Analysis of MPPT for Power Quality Improvement

    Directory of Open Access Journals (Sweden)

    S. Sankar

    2015-08-01

    Full Text Available In this study the conventional inverter interfacing renewable energy sources with the grid, without any additional hardware cost. Here, the main idea is the maximum utilization of inverter rating which is most of the time underutilized due to intermittent nature of RES. Based on the non-linear characteristics of PV, these thesis designs a VSS controller to realize the maximum power output of PV arrays. The output power from renewable energy sources fluctuates because of weather variations. This study proposes an effective power quality control strategy of renewable energy sources connected to power system using Photovoltaic (PV array. If the main controller used is a PR controller, any dc offset in a control loop will propagate through the system and the inverter terminal voltage will have a nonzero average value. In this strategy both load and inverter current sensing is required to compensate the load current harmonics. The non-linear load current harmonics may result in voltage harmonics and can create a serious PQ problem in the power system network.

  6. Wind speed power spectrum analysis for Bushland, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Eggleston, E.D. [USDA-Agricultural Research Service, Bushland, TX (United States)

    1996-12-31

    Numerous papers and publications on wind turbulence have referenced the wind speed spectrum presented by Isaac Van der Hoven in his article entitled Power Spectrum of Horizontal Wind Speed Spectrum in the Frequency Range from 0.0007 to 900 Cycles per Hour. Van der Hoven used data measured at different heights between 91 and 125 meters above the ground, and represented the high frequency end of the spectrum with data from the peak hour of hurricane Connie. These facts suggest we should question the use of his power spectrum in the wind industry. During the USDA - Agricultural Research Service`s investigation of wind/diesel system power storage, using the appropriate wind speed power spectrum became a significant issue. We developed a power spectrum from 13 years of hourly average data, 1 year of 5 minute average data, and 2 particularly gusty day`s 1 second average data all collected at a height of 10 meters. While the general shape is similar to the Van der Hoven spectrum, few of his peaks were found in the Bushland spectrum. While higher average wind speeds tend to suggest higher amplitudes in the high frequency end of the spectrum, this is not always true. Also, the high frequency end of the spectrum is not accurately described by simple wind statistics such as standard deviation and turbulence intensity. 2 refs., 5 figs., 1 tab.

  7. Modeling Analysis and Improvement of Power Loss in Microgrid

    Directory of Open Access Journals (Sweden)

    H. Lan

    2015-01-01

    Full Text Available The consumption of conventional energy sources and environmental concerns have resulted in rapid growth in the amount of renewable energy introduced to power systems. With the help of distributed generations (DG, the improvement of power loss and voltage profile can be the salient benefits. However, studies show that improper placement and size of energy storage system (ESS lead to undesired power loss and the risk of voltage stability, especially in the case of high renewable energy penetration. To solve the problem, this paper sets up a microgrid based on IEEE 34-bus distribution system which consists of wind power generation system, photovoltaic generation system, diesel generation system, and energy storage system associated with various types of load. Furthermore, the particle swarm optimization (PSO algorithm is proposed in the paper to minimize the power loss and improve the system voltage profiles by optimally managing the different sorts of distributed generations under consideration of the worst condition of renewable energy production. The established IEEE 34-bus system is adopted to perform case studies. The detailed simulation results for each case clearly demonstrate the necessity of optimal management of the system operation and the effectiveness of the proposed method.

  8. An Experimental Analysis of Asymmetric Power in Conflict Bargaining

    Directory of Open Access Journals (Sweden)

    William Reed

    2013-08-01

    Full Text Available Demands and concessions in a multi-stage bargaining process are shaped by the probabilities that each side will prevail in an impasse. Standard game-theoretic predictions are quite sharp: demands are pushed to the precipice with nothing left on the table, but there is no conflict regardless of the degree of power asymmetry. Indeed, there is no delay in reaching an agreement that incorporates the (unrealized costs of delay and conflict. A laboratory experiment has been used to investigate the effects of power asymmetries on conflict rates in a two-stage bargaining game that is (if necessary followed by conflict with a random outcome. Observed demands at each stage are significantly correlated with power, as measured by the probability of winning in the event of disagreement. Demand patterns, however, are flatter than theoretical predictions, and conflict occurs in a significant proportion of the interactions, regardless of the degree of the power asymmetry. To address these deviations from the standard game-theoretic predictions, we also estimated a logit quantal response model, which generated the qualitative patterns that are observed in the data. This one-parameter generalization of the Nash equilibrium permits a deconstruction of the strategic incentives that cause demands to be less responsive to power asymmetries than Nash predictions.

  9. Performance analysis of OTEC power cycle with a liquid-vapor ejector using R32/R152a

    Science.gov (United States)

    Yoon, Jung-In; Son, Chang-Hyo; Seol, Sung-hoon; Kim, Hyeon-Uk; Ha, Soo-Jung; Jung, Suk-Ho; Kim, Hyeon-Ju; Lee, Ho-Saeng

    2015-11-01

    In this paper, the condensation and evaporation capacity, turbine work, efficiency, and main component size of the Ocean Thermal Energy Conversion (OTEC) power system with a liquid-vapor ejector are presented to offer the basic design data for the operating parameters of the system. The analysis procedure was performed with a simulation program called Aspentech HYSYS. The working fluid used in this system is the R32/R152a mixture. The operating parameters considered in this study include the vapor quality at the reheat outlet, the pressure ratio of the ejector, the inlet pressure of turbine 2, entrainment ratio of the liquid-vapor ejector etc. The main results are summarized as follows. The efficiency of the OTEC power cycle is closely related to the entrainment ratio of the liquid-vapor ejector. Also, the increase rate of the efficiency of proposed OTEC power cycle using the liquid-vapor ejector is 16 % higher than that of basic OTEC power cycle. Furthermore, regarding the reduction ratios of the system size that affects the initial cost, the reduction ratios of the evaporator size and the condenser size are about 13 and 14 % higher than those of basic OTEC power cycle, respectively. And, the pump power and the mass flow rate of the required refrigerant are 8 and 4 %, respectively. Therefore, the proposed OTEC power cycle is more advantageous than basic OTEC power cycle because of the compactness and high-efficiency of the system.

  10. Hybrid PV/diesel solar power system design using multi-level factor analysis optimization

    Science.gov (United States)

    Drake, Joshua P.

    Solar power systems represent a large area of interest across a spectrum of organizations at a global level. It was determined that a clear understanding of current state of the art software and design methods, as well as optimization methods, could be used to improve the design methodology. Solar power design literature was researched for an in depth understanding of solar power system design methods and algorithms. Multiple software packages for the design and optimization of solar power systems were analyzed for a critical understanding of their design workflow. In addition, several methods of optimization were studied, including brute force, Pareto analysis, Monte Carlo, linear and nonlinear programming, and multi-way factor analysis. Factor analysis was selected as the most efficient optimization method for engineering design as it applied to solar power system design. The solar power design algorithms, software work flow analysis, and factor analysis optimization were combined to develop a solar power system design optimization software package called FireDrake. This software was used for the design of multiple solar power systems in conjunction with an energy audit case study performed in seven Tibetan refugee camps located in Mainpat, India. A report of solar system designs for the camps, as well as a proposed schedule for future installations was generated. It was determined that there were several improvements that could be made to the state of the art in modern solar power system design, though the complexity of current applications is significant.

  11. Application of Designing Economic Mechanisms to Power Market - Part 2 Characteristic Analysis of Generation Side Power Market

    Directory of Open Access Journals (Sweden)

    ZHU Yonggang

    2013-04-01

    Full Text Available The incentive power market may lead to a high information cost if it is not informationally efficient. The paper analyzes the characteristic of the generation side power market mechanism model based on the designing economic mechanisms theory by the three GENCOs (Generation Companies case. The result of analysis is that the mechanism model has four main features: the informationally efficient which means that the mechanism meets requirements of the observational efficiency, the communication efficiency and the low complexity of computing; the incentive compatibility which indicates that the resource allocation of the power market is Pareto Optimality and the social benefit achieves the maximization when GENCOs also achieve profit maximization; the decentralized decision which refers to preserving the privacy information of GENCOs; encouragement of competition which suggests that the mechanism encourages GENCOs to compete with each other healthily.

  12. Balance of the LVC plant with increase in 15 % of power; Balance de planta de la CLV con aumento del 15 % de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, J.J.; Hernandez, J.L.; Perusquia, R.; Castillo, A.; Montes, J.L. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: jjortiz@nuclear.inin.mx

    2005-07-01

    One of the tendencies in many power reactors has been to modify some operation conditions, in order to increasing the electricity generation. The Laguna Verde Nuclear power plant (CNLV) it has not been the exception and in the recent past an increment of 5% was made in the original nominal thermal power. In the face of the possibility of carrying out more modifications, a study was made in the one that one simulates an eventual increment of the power of the reactor in 15% of the original value. With this increment one carries out the balance of the plant and the thermodynamic properties were determined. With this purpose it was developed a computer tool to calculate the thermodynamic properties of the plant in several points of the power cycle, as well as to carry out energy and mass balances to determine the flows in the different extractions of steam of the turbines. The program is compared with the results to 100% and 105% of increase of power obtaining good results, for what it is concluded that the extrapolation to 115% of power increase is acceptable. (Author)

  13. Service Oriented Architectural Model for Load Flow Analysis in Power Systems

    Science.gov (United States)

    Muthu, Balasingh Moses; Veilumuthu, Ramachandran; Ponnusamy, Lakshmi

    2011-07-01

    The main objective of this paper is to develop the Service Oriented Architectural (SOA) Model for representation of power systems, especially of computing load flow analysis of large interconnected power systems. The proposed SOA model has three elements namely load flow service provider, power systems registry and client. The exchange of data using XML makes the power system services standardized and adaptable. The load flow service is provided by the service provider, which is published in power systems registry for enabling universal visibility and access to the service. The message oriented style of SOA using Simple Object Access Protocol (SOAP) makes the service provider and the power systems client to exist in a loosely coupled environment. This proposed model, portraits the load flow services as Web services in service oriented environment. To suit the power system industry needs, it easily integrates with the Web applications which enables faster power system operations.

  14. Dynamic Analysis of Permanent Magnet Synchronous Generator with Power Electronics

    Directory of Open Access Journals (Sweden)

    OZCIRA, S.

    2010-05-01

    Full Text Available Permanent magnet DC motor-generators (PMDC, PMSG have been widely used in industrial and energy sectors recently. Power control of these systems can be achieved by controlling the output voltage. In this study, PMDC-PMSG systems are mathematically modeled and simulated in MATLAB and Simulink software. Then the results are discussed. A low power permanent magnet synchronous generator is driven by a permanent magnet DC motor and the output voltage is controlled by a frequency cycle-converter. The output of a half-wave uncontrolled rectifier is applied to an SPWM inverter and the power is supplied to a 300V, 50Hz load. The load which is connected to an LC filter is modeled by state-space equations. LC filter is utilized in order to suppress the voltage oscillations at the inverter output.

  15. Electrical Power Budgeting Analysis for LSA-02 UAV Technology Demonstrator

    Science.gov (United States)

    Pranoto, F. S.; Wirawan, A.; Purnamasari, D. A.

    2016-11-01

    This paper addresses the calculation of the LSA-02 UAV electrical power requirement as a technology demonstrator. To answer this issue, the method from ASTM F2490 Standard is used. By adopting that method, the condition of aircraft operation must be defined. Therefore, there are 2 aircraft conditions that will be investigated further. First, the LSA-02 aircraft will be fitted with EO/IR camera and support payload for conducting real-time surveillance system. The other condition is conducting the aerial photography mission to investigate the vegetation condition by equipping the aircraft with a multispectral camera. The results show that the real-time mission will need bigger electrical power requirement comparing to aerial photography mission. To support the mission without sacrificing the other electrical equipment for functioning, the onboard power generator system inside LSA-02 aircraft should be upgraded, at least with 3.5 kVA capacity.

  16. Analysis of heat transfer in portable power supply

    Science.gov (United States)

    Abdullah, Mohd Azman; Ali, Ahmad Nazrin

    2016-03-01

    Portable power supply (PPS) is developed based on the necessity in supplying instant power to support domestic appliances during power shortage or in remote area. In this paper, the heat transfer inside the PPS is analyzed and demonstrated by temperature change during battery charging and discharging. The computational fluid dynamic (CFD) model of the PPS battery and housing are developed. The heat flow inside the PPS is studied at different conditions of battery and air flows. The increment of the temperature inside the PPS could cause the PPS system to damage and unsafe. Few elements are manipulated for the study, such as battery positions, holedimensions and fan models in order toimprove the design of PPS. Experimental approach is also conducted to validate the temperature and heat transfer in the PPS.

  17. Tensile Stiffness Analysis on Ocean Dynamic Power Umbilical

    Institute of Scientific and Technical Information of China (English)

    汤明刚; 阎军; 王野; 岳前进

    2014-01-01

    Tensile stiffness of ocean dynamic power umbilical is an important design parameter for functional implementation and structural safety. A column with radial stiffness which is wound by helical steel wires is constructed to predict the tensile stiffness value of umbilicals in the paper. The relationship between the tension and axial deformation is expressed analytically so the radial contraction of the column is achieved in the relationship by use of a simple finite element method. With an agreement between the theoretical prediction and the tension test results, the method is proved to be simple and efficient for the estimation of tensile stiffness of the ocean dynamic power umbilical.

  18. Conceptual design and systems analysis of photovoltaic power systems. Final report. Volume III(2). Technology

    Energy Technology Data Exchange (ETDEWEB)

    Pittman, P.F.

    1977-05-01

    Conceptual designs were made and analyses were performed on three types of solar photovoltaic power systems. Included were Residential (1 to 10 kW), Intermediate (0.1 to 10 MW), and Central (50 to 1000 MW) Power Systems to be installed in the 1985 to 2000 time period. The following analyses and simulations are covered: residential power system computer simulations, intermediate power systems computer simulation, central power systems computer simulation, array comparative performance, utility economic and margin analyses, and financial analysis methodology.

  19. Mathematical simulation of the operating emergency conditions for the purpose of energy efficiency increase of thermal power plants management

    Science.gov (United States)

    Gazizova, O. V.; Malafeyev, A. V.; Kondrashova, Y. N.

    2016-04-01

    The regulations of the energy saving policy, being implemented at present, require an enhanced reliability of the power supply systems and operations of the motive loading, actuating machines and mechanisms, for the purpose of reduction of power inputs under operating emergency conditions. The development of industrial units of the distributed generation enables putting the generators, equipped with motors of the comparable power, into the operation, which is non-parallel to a power system. To provide static stability under such conditions the complex approach is required since it allows estimating the stability of the generators and the load during parallel and non-parallel operations with the power system and a complex circuit configuration. The mathematical models of units of the distributed generation and motive loading considering the character of the given mechanism are developed. They are implemented in the software package allowing the operative-dispatch personnel of the industrial power stations to forecast similar modes and develop special measures to provide a stable operation of electrical machines.

  20. Statistical Power Analysis with Missing Data A Structural Equation Modeling Approach

    CERN Document Server

    Davey, Adam

    2009-01-01

    Statistical power analysis has revolutionized the ways in which we conduct and evaluate research.  Similar developments in the statistical analysis of incomplete (missing) data are gaining more widespread applications. This volume brings statistical power and incomplete data together under a common framework, in a way that is readily accessible to those with only an introductory familiarity with structural equation modeling.  It answers many practical questions such as: How missing data affects the statistical power in a study How much power is likely with different amounts and types