WorldWideScience

Sample records for brownouts

  1. The Use of Commercial Remote Sensing Predicting Helicopter Brownout Conditions

    Science.gov (United States)

    2007-09-01

    landing. 4 Figure 2. Soil caught in rotor downwash, start of brownout (from Brownout California soil resource lab) . A second issue ...Sensing in Predicting Helicopter Brownout Conditions. September 2006 (Top Secret). Tan, Kim H., First Edition, Enviromental Soil Science Marcel

  2. Flight test of MMW radar for brown-out helicopter landing

    Science.gov (United States)

    Martin, Christopher A.; Kolinko, Vladimir; Otto, Gregory P.; Lovberg, John A.

    2012-06-01

    Trex Enterprises and US Army RDECOM CERDEC Night Vision Electronic Sensors Directorate developed and tested helicopter radar to aid in brown-out landing situations. A brown-out occurs when sand and dust kicked up by the helicopter rotors impair the pilot's vision. Millimeter-wave (MMW) radiation penetrates sand and dust with little loss or scattering, and radar at this frequency can provide a pilot with an image of the intended landing zone. The Brown-out Situational Awareness System (BSAS) is a frequency-modulated, continuous-wave radar that measures range to the ground across a conical field-of-view and uses that range information to create an image for the pilot. The BSAS collected imagery from a helicopter in a blowing sand environment with obstacles including ditches, hills, posts, poles, wires, buildings and vehicles. The BSAS proved the capability to form images of the ground through heavy blowing sand and resolve images of some obstacles. The BSAS also attempted to differentiate flat ground from bumpy ground with limited success at some viewing angles. The BSAS test imagery includes some artifacts formed by high radar cross-section targets in the field-of-view or sidelobes. The paper discusses future improvements that could limit these artifacts.

  3. Rotorcraft Brownout Advanced Understanding, Control, and Mitigation

    Science.gov (United States)

    2014-10-31

    Ad- vanced Rotorcraft Technology and Safety Operations, Omiya, Japan, November 1–3, 2010. 22. Geiser , J., and Kiger, K. T., “Vortex Ring Breakdown...Forum Proceedings, Gallarate, Italy, September 13–15, 2011. 37. Kiger, K. T., and Geiser , J., “Vortex Ring Breakdown Induced by Topographic Forcing...11 39. Geiser , J., and Kiger, K. T., “Effects of Ground Plane Topology on Vortex-Ground Interac- tions in a Forced Impinging Jet,” 64th Annual

  4. Mechanisms of Sediment Entrainment and Transport in Rotorcraft Brownout

    Science.gov (United States)

    2009-01-01

    Because of the self- and mutually-induced effects on helicoidal wake vortices, the flow induced by a rotor can be aperiodic (Refs. 45–49). The levels...produce more periodic flows is to reduce the number of blades on the rotor, so as to give a single helicoidal vortex filament in the wake. For this...PIV Measurements of the Flow Around Systems of Bubbles Rising in Water ,” Proceedings of the ASME Fluids Engineering Division Summer Conference, June

  5. Physics Based Modeling of Helicopter Brownout for Piloted Simulation Applications

    Science.gov (United States)

    2008-12-01

    for over 40 years in many applications including erosion modeling, sand dune formation and nuclear blast waves (l-Iartenbaum, 1971; Mirels , 1984...Environment." American ’Helicopter Society 6I~\\ Annual Forum, Grapevine, TX, June 2005. Mirels , H. (1984). "Blowing Model for Turbolent BoundarywLayer Dust

  6. Rotary-Wing Brownout Mitigation: Technologies and Training (Remedes contre le phenomene de brownout sur les appareils a voilure tournante: Technologies et entrainement)

    Science.gov (United States)

    2012-01-01

    on the US Army Fly-by-Wire RASCAL UH-60 Figure A-4 Flight Test Result – Maximum Low Altitude Error A-3 Figure A-5 Flight Test Result – Max. Ground...Army and the DLR both operate experimental helicopters equipped with active inceptors. The U.S. Army AMRDEC RASCAL helicopter features an active...worked both with and without a predetermined route. This display was tested in simulation first, and later in flight test on the US Army RASCAL fly

  7. Sandblaster 2 Support of See-Through Technologies for Particulate Brownout

    Science.gov (United States)

    2007-10-31

    particles. Photomicrographs of the YPG and Iraq soils are shown in Figure 14. Particle size and shape characteristics of the two test soils are similar...Both Yuma and Iraq soils showed an abundance of calcite, but the formations differed. Calcite in the Yuma dust occurs as discrete clasts . Calcite...in the Iraq dust occurs as very fine-grained coatings on monomineralic clasts and as aggregates mixed with other fine-grained phases. In the Iraq

  8. An Examination of a Pumping Rotor Blade Design for Brownout Mitigation

    Science.gov (United States)

    2015-05-18

    tip to the lower pressure air above the blade, resulting in a circulatory flow. Each rotor blade trails a single concentrated tip vortex , which forms a...introduced into the flow. Vortex induced trapping refers to the uplift of particles entrained in the flow by the upward swirl velocities of a vortex ...sediment entrainment are depen- dent on the intensity of the tip vortices in the wake, it is expected that a reduction in tip vortex intensity may

  9. Investigating the Impacts of Particle Size and Wind Speed on Brownout

    Science.gov (United States)

    2015-03-26

    threshold wind friction velocity due to soil mois- ture for arod and semi - arid areas. Annales Geophysicae, Vol. 17, pp 149-157. Ghosh, S., Lohry, M.W...curs on short time and spatial scales when atmospheric and surface conditions are favorable. The potential for rotor downwash exists in arid regions...aerosols can contain chemicals that have the potential to affect weather and climate , ecosystems, public health, the hydrologic cycle, and agriculture. 11

  10. FlyTact : A tactile display improves a helicopter pilot's landing performance in degraded visual environments

    NARCIS (Netherlands)

    Jansen, C.; Wennemers, A.S.; Vos, W.K.; Groen, E.L.

    2008-01-01

    Helicopter landings are more challenging in 'brownout' conditions, in which sand and dust is stirred up by the rotary wing aircraft, obscuring visibility. Safe brownout landings require new sensor and display technologies to provide the pilot with information on helicopter motion. In this respect

  11. United States Air Force Agency Financial Report 2013

    Science.gov (United States)

    2013-01-01

    Accounting and Management System (DEAMS) DEAMS is the Air Force financial management Enterprise Resource Planning ( ERP ) system that uses industry...perception to mitigate the risk of brownout clouds to pilots, ground crews and flight hardware. Fundamental basic science studies of the fluid...fidelity computational models of brownout clouds , which were subsequently validated with experimental testing. This was combined with research into novel

  12. Mars Atmospheric Entry Integrated Navigation with Partial Intermittent Measurements

    Directory of Open Access Journals (Sweden)

    Tai-shan Lou

    2017-01-01

    Full Text Available Signal degradation suffered by the vehicle is a combination brownout and blackout during Mars atmospheric entry. The communications brownout means that signal fades and blackout means that the signal is lost completely. The communications brownout and blackout periods are analyzed and predicted with an altitude and velocity profiles. In the brownout period, the range measurements between the vehicle and the orbiters are modeled as intermittent measurements with the radio signal arrival probabilities, which are distributed as a Rayleigh distribution of the electron number density around the entry vehicle. A new integrated navigation strategy during the Mars atmospheric entry phase is proposed to consider the probabilities of the radio measurements in the communications brownout and blackout periods under the IMU/beacon scenario based on the information filter with intermittent measurements. Numerical navigation simulations are designed to show the performance of the proposed navigation strategy under the integrated navigation scenario.

  13. Development of an early warning sensor and network for brown-\\0xAD\\0x2010out conditions.

    Science.gov (United States)

    2016-03-31

    Brownout conditions on motorways are caused by windblown dust and sand from upwind areas where : soils are susceptible to wind erosion. Owing in part to prolonged droughts that have dried : soils and denuded vegetation and biological crusts, large, m...

  14. View presentation

    Indian Academy of Sciences (India)

    The Approach · Instant Brown-out Signalling to homes · But what will 10% DC Power do? The Power Distribution Innovation achieves · Unburdening Electrical Grid · Multiplying Investments · India needs to Lead and not follow · Can India's 50% vehicles be Electric by 2030? We can get there · To Conclude: India can aim big.

  15. 7 CFR 760.611 - Qualifying losses, eligible causes and types of loss.

    Science.gov (United States)

    2010-01-01

    ... loss was due to poor management decisions or poor farming practices, as determined by the FSA county...) Losses caused by a failure of power supply or brownout as defined in § 760.602; (2) Losses caused by the...; (4) Losses caused by the application of chemicals; (5) Losses caused by theft or fire not caused by a...

  16. The GridShare solution: a smart grid approach to improve service provision on a renewable energy mini-grid in Bhutan

    Science.gov (United States)

    Quetchenbach, T. G.; Harper, M. J.; Robinson, J., IV; Hervin, K. K.; Chase, N. A.; Dorji, C.; Jacobson, A. E.

    2013-03-01

    This letter reports on the design and pilot installation of GridShares, devices intended to alleviate brownouts caused by peak power use on isolated, village-scale mini-grids. A team consisting of the authors and partner organizations designed, built and field-tested GridShares in the village of Rukubji, Bhutan. The GridShare takes an innovative approach to reducing brownouts by using a low cost device that communicates the state of the grid to its users and regulates usage before severe brownouts occur. This demand-side solution encourages users to distribute the use of large appliances more evenly throughout the day, allowing power-limited systems to provide reliable, long-term renewable electricity to these communities. In the summer of 2011, GridShares were installed in every household and business connected to the Rukubji micro-hydro mini-grid, which serves approximately 90 households with a 40 kW nominal capacity micro-hydro system. The installation was accompanied by an extensive education program. Following the installation of the GridShares, the occurrence and average length of severe brownouts, which had been caused primarily by the use of electric cooking appliances during meal preparation, decreased by over 92%. Additionally, the majority of residents surveyed stated that now they are more certain that their rice will cook well and that they would recommend installing GridShares in other villages facing similar problems.

  17. Mains voltage profile in Dar es Salaam: A case study | Mvungi ...

    African Journals Online (AJOL)

    ... 40% and surges as high 17.4% above the normal value. The paper further proposes methods to address the problems at the consumer end. Keywords: Voltage instability, under-voltage, over-voltage, shedding, brownouts, voltage dips, voltage sags, voltage regulation. Journal of Agriculture, Science and Technology Vol.

  18. Optimal Dispatch of an Industrial Microgrid with a Mixed Portfolio of Distributed Energy Resources

    DEFF Research Database (Denmark)

    You, Shi; Zong, Yi; Bindner, Henrik W.

    2014-01-01

    Local brownouts are a nuisance and have driven consumers to take greater responsibility for their electricity supply – particularly industries and communities with a critical need for reliable and safe power. By deploying a Microgrid on their own site, the consumers could benefit from having this...... this interoperable grid solution with respect to improved energy efficiency, system reliability and power quality. When the on-site generation is from renewables, external incentives and system sustainability could make the Microgrid solution even more attractive......Local brownouts are a nuisance and have driven consumers to take greater responsibility for their electricity supply – particularly industries and communities with a critical need for reliable and safe power. By deploying a Microgrid on their own site, the consumers could benefit from having...

  19. Measurements to Understand the Flow Mechanisms Contributing to Tandem Rotor Outwash

    Science.gov (United States)

    2015-05-23

    pilot visibility issues in brownout, dust entrain - ment into engine inlets, blade erosion, and increased air - craft maintenance. Though almost 50 years...viscous shear ( vortex ring instabili- ties). Laser light sheet flow visualization images and PIV measurements were acquired in free air at a nozzle...the aircraft, an increase in rotor height above ground decreased the outwash velocity at all air - craft azimuths. However, farther away, the

  20. Show it with colors; Connectivity, status, and value information in energy management systems

    Energy Technology Data Exchange (ETDEWEB)

    Imhof, K.; Arias, C. (ABB Network Control Ltd. (CH))

    1990-10-01

    While maintenance, interchange arrangement, and such are important uses of energy management systems (EMS), grasping an overview of which power system parts are still supplied with electric power and which are disconnected after a brownout or blackout requires a skilled operator and/or sophisticated EMS functionalities. Finding out in a complex power station which feeders are energized is an operator's basic task, which may severely burden the user. Getting an overview of whether a certain network is observable and thus estimated, or is determined based on non-telemetered, unreliable information, is usually outside the operator's capabilities. Show it with colors aims to improve the operator's capability to manage a power system by providing information in a form that is adequate for him. This article reports on a first implementation and some feedback from customers.

  1. Ramos` private-power policies pay off

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    This article reports that political stability, government incentives attract foreign capital for new generating plants and T and D facilities. Teams of multinational lenders, developers, equipment vendors, engineering contractors erect critical plants in record time. As recently as the summer of 1993, the Republic of the Philippines was teetering on the brink of bankruptcy--mainly because of electricity shortages. Brownouts averaging seven hours a day were common nationwide, and Manila`s business districts were frequently blacked out for most of the day. With the nation of 67-million facing economic losses estimated at several billion dollars a year, President Fidel V. Ramos took swift, decisive action. Ramos, elected the previous year, accelerated power-sector reforms initiated by his predecessor, Corazon C. Aquino, that sought to augment the aging, unreliable generating capacity of the state-owned electric utility with private power development.

  2. China Cools with Tighter RAC Standards

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jiang; Rosenquist, Gregory

    2006-06-01

    After boiling summer brought brown-out to most part of the country in 2004, China announced a new set of minimum energy efficiency standards for room air conditioners in September 2004, with the first tier going into effect on March 1, 2005 and the reach standard taking effect on January 1, 2009. This represents a milestone in China's standard setting process since the reach standard levels are significantly more stringent than previous standards for other appliances. This paper first analyzes cost-effectiveness of China's new standards for room air conditioners, and then attempts to evaluate the impact of the new standards on energy savings, electric generation capacity, and CO2 emissions reductions.

  3. Operations managers conference: summary of proceedings. [Carmel, California, Feb. 13-15, 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-02-01

    The fifth AESOP Operations Managers Conference was held in Carmel, California on February 13-15, 1979. The keynote address dealt with the changing role of the computer operations manager. Representatives presented contrasting approaches to managing the procurement and installation of new computer systems. The advantages and disadvantages of maintaining strong internal management support and good communication with the vendor and of increasing the involvement of broad-based planning committees and operations personnel in the computer procurement process were discussed. Two promising management programs, the PEER and 10/40 systems proved effective in improving employee morale by reducing job fragmentation, increasing internal mobility and modifying the work week. The topic of unionization of operations personnel was also discussed. The uneasy relationship between computers and the energy shortage was also considered. Techniques for avoiding computer problems caused by blackouts and brownouts were presented. The difficulty of conserving power at a computer facility was also discussed. Presentations concerning the President's committee on ADP reorganizaion and methods for predicting trends in computer innovation were made. Abstracts and two-page summaries of the papers given are included in this report.

  4. Cellular computational generalized neuron network for frequency situational intelligence in a multi-machine power system.

    Science.gov (United States)

    Wei, Yawei; Venayagamoorthy, Ganesh Kumar

    2017-09-01

    To prevent large interconnected power system from a cascading failure, brownout or even blackout, grid operators require access to faster than real-time information to make appropriate just-in-time control decisions. However, the communication and computational system limitations of currently used supervisory control and data acquisition (SCADA) system can only deliver delayed information. However, the deployment of synchrophasor measurement devices makes it possible to capture and visualize, in near-real-time, grid operational data with extra granularity. In this paper, a cellular computational network (CCN) approach for frequency situational intelligence (FSI) in a power system is presented. The distributed and scalable computing unit of the CCN framework makes it particularly flexible for customization for a particular set of prediction requirements. Two soft-computing algorithms have been implemented in the CCN framework: a cellular generalized neuron network (CCGNN) and a cellular multi-layer perceptron network (CCMLPN), for purposes of providing multi-timescale frequency predictions, ranging from 16.67 ms to 2 s. These two developed CCGNN and CCMLPN systems were then implemented on two different scales of power systems, one of which installed a large photovoltaic plant. A real-time power system simulator at weather station within the Real-Time Power and Intelligent Systems (RTPIS) laboratory at Clemson, SC, was then used to derive typical FSI results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The marginalization of "small is beautiful": Micro-hydroelectricity, common property, and the politics of rural electricity provision in Thailand

    Science.gov (United States)

    Greacen, Christopher Edmund

    This study analyzes forces that constrain sustainable deployment of cost-effective renewable energy in a developing country. By many economic and social measures, community micro-hydro is a superior electrification option for remote mountainous communities in Thailand. Yet despite a 20 year government program, only 59 projects were built and of these less than half remain operating. By comparison, the national grid has extended to over 69,000 villages. Based on microeconomic, engineering, social barriers, common pool resource, and political economic theories, this study investigates first, why so few micro-hydro projects were built, and second, why so few remain operating. Drawing on historical information, site visits, interviews, surveys, and data logging, this study shows that the marginal status of micro-hydro arises from multiple linked factors spanning from village experiences to geopolitical concerns. The dominance of the parastatal rural electrification utility, the PEA, and its singular focus on grid extension are crucial in explaining why so few projects were built. Buffered from financial consequences by domestic and international subsidies, grid expansion proceeded without consideration of alternatives. High costs borne by villagers for micro-hydro discouraged village choice. PEA remains catalytic in explaining why few systems remain operating: grid expansion plans favor villages with existing loads and most villages abandon micro-hydro generators when the grid arrives. Village experiences are fundamental: most projects suffer blackouts, brownouts, and equipment failures due to poor equipment and collective over-consumption. Over-consumption is linked to mismatch between tariffs and generator technical characteristics. Opportunities to resolve problems languished as limited state support focused on building projects and immediate repairs rather than fundamentals. Despite frustrations, many remain proud of "their power plant". Interconnecting and selling

  6. Automated Demand Response Approaches to Household Energy Management in a Smart Grid Environment

    Science.gov (United States)

    Adika, Christopher Otieno

    The advancement of renewable energy technologies and the deregulation of the electricity market have seen the emergence of Demand response (DR) programs. Demand response is a cost-effective load management strategy which enables the electricity suppliers to maintain the integrity of the power grid during high peak periods, when the customers' electrical load is high. DR programs are designed to influence electricity users to alter their normal consumption patterns by offering them financial incentives. A well designed incentive-based DR scheme that offer competitive electricity pricing structure can result in numerous benefits to all the players in the electricity market. Lower power consumption during peak periods will significantly enhance the robustness of constrained networks by reducing the level of power of generation and transmission infrastructure needed to provide electric service. Therefore, this will ease the pressure of building new power networks as we avoiding costly energy procurements thereby translating into huge financial savings for the power suppliers. Peak load reduction will also reduce the inconveniences suffered by end users as a result of brownouts or blackouts. Demand response will also drastically lower the price peaks associated with wholesale markets. This will in turn reduce the electricity costs and risks for all the players in the energy market. Additionally, DR is environmentally friendly since it enhances the flexibility of the power grid through accommodation of renewable energy resources. Despite its many benefits, DR has not been embraced by most electricity networks. This can be attributed to the fact that the existing programs do not provide enough incentives to the end users and, therefore, most electricity users are not willing to participate in them. To overcome these challenges, most utilities are coming up with innovative strategies that will be more attractive to their customers. Thus, this dissertation presents various

  7. Third Generation Flywheels for electric storage

    Energy Technology Data Exchange (ETDEWEB)

    Ricci, Michael, R.; Fiske, O. James

    2008-02-29

    frequency regulation, where Power Rings could cut costs, reduce fuel consumption, eliminate emissions, and reduce the need for new power plants. Other applications include hybrid diesel-electric locomotives, grid power quality, support for renewable energy, spinning reserve, energy management, and facility deferral. Decreased need for new generation and transmission alone could save the nation $2.5 billion per year. Improved grid reliability could cut economic losses due to poor power quality by tens of billions of dollars per year. A large export market for this technology could also develop. Power Ring technology will directly support the EERE mission, and the goals of the Distributed Energy Technologies Subprogram in particular, by helping to reduce blackouts, brownouts, electricity costs, and emissions, by relieving transmission bottlenecks, and by greatly improving grid power quality.

  8. Basic Research Needs for Superconductivity. Report of the Basic Energy Sciences Workshop on Superconductivity, May 8-11, 2006

    Energy Technology Data Exchange (ETDEWEB)

    Sarrao, J.; Kwok, W-K; Bozovic, I.; Mazin, I.; Seamus, J. C.; Civale, L.; Christen, D.; Horwitz, J.; Kellogg, G.; Finnemore, D.; Crabtree, G.; Welp, U.; Ashton, C.; Herndon, B.; Shapard, L.; Nault, R. M.

    2006-05-11

    As an energy carrier, electricity has no rival with regard to its environmental cleanliness, flexibility in interfacing with multiple production sources and end uses, and efficiency of delivery. In fact, the electric power grid was named ?the greatest engineering achievement of the 20th century? by the National Academy of Engineering. This grid, a technological marvel ingeniously knitted together from local networks growing out from cities and rural centers, may be the biggest and most complex artificial system ever built. However, the growing demand for electricity will soon challenge the grid beyond its capability, compromising its reliability through voltage fluctuations that crash digital electronics, brownouts that disable industrial processes and harm electrical equipment, and power failures like the North American blackout in 2003 and subsequent blackouts in London, Scandinavia, and Italy in the same year. The North American blackout affected 50 million people and caused approximately $6 billion in economic damage over the four days of its duration. Superconductivity offers powerful new opportunities for restoring the reliability of the power grid and increasing its capacity and efficiency. Superconductors are capable of carrying current without loss, making the parts of the grid they replace dramatically more efficient. Superconducting wires carry up to five times the current carried by copper wires that have the same cross section, thereby providing ample capacity for future expansion while requiring no increase in the number of overhead access lines or underground conduits. Their use is especially attractive in urban areas, where replacing copper with superconductors in power-saturated underground conduits avoids expensive new underground construction. Superconducting transformers cut the volume, weight, and losses of conventional transformers by a factor of two and do not require the contaminating and flammable transformer oils that violate urban safety

  9. The Hydrogen Economy Making the Transition to the Third Industrial Revolution and a New Energy Era

    Energy Technology Data Exchange (ETDEWEB)

    Jeremy Rifkin

    2006-07-01

    ;forever fuel'. It never runs out and produces no harmful CO{sub 2} emissions. Commercial fuel-cells powered by hydrogen are just now being introduced into the market for home, office and industrial use. Hitachi, Toshiba, and other companies will be introducing the first hydrogen fuel cell cartridges into retail stores around the world in 2007. The small hydrogen powered micro fuel cells will replace traditional batteries and provide mobile power for lap-top computers, cell phones, PDA's, Mp3 players, camcorders, portable DVD players, hand- held computers, video games, and digital cameras. With this new energy source, computers can be powered for days at a time, where existing battery technology lasts only a few hours before needing to be plugged back into the wall socket to be recharged. Similarly, manufacturing and service-related companies are just beginning to introduce stationary fuel cell power plants to provide back-up generation during periods of peak load or when the price of electricity on the grid becomes too expensive, or when the grid cannot keep up with demand surges, resulting in rolling brownout and blackouts. Indeed, when the massive 2002 power blackout shut down large parts of the Northeast and Midwestern part of the US and the New York City skyline went black, a newly erected skyscraper in Times Square remained fully lit and powered up because a stationary fuel cell power plant had been built into its infrastructure. The German company, Linde AG, recently introduced a hydrogen fuel cell power plant at the Munich airport. The hydrogen economy makes possible a broad redistribution of power, with far-reaching beneficial consequences for society. In the new era, businesses, municipalities and homeowners could become the producers as well as the consumers of their own energy so-called 'distributed generation'. Even the automobile itself is a 'power station on wheels' with a generating capacity of twenty kilowatts. Since the average