Showing papers on "Base load power plant published in 2003"

Power conversion in variable load applications

Abstract: A power conversion unit (100) and method for efficient conversion of power for one or more variable loads (132, 134) are disclosed herein. Power having a first ferin is supplied to one or more power conversion units (PCUs) (122, 124, 126) connected to the one or more variable loads. The PCUs are adapted to convert the power form the first forir, to other forms suitable for use by die components of the destination system (120). Based at least in part on a predicted load requirement of the variable load, the operation of the PCUs can be controlled to provide sufficient power to the one or more loads at the appropriate time while minimizing wasted power generation by deactivating any unnecessary PCUs during a decrease in power consumption or by activating PCUs during an increase in power consumption. Additionally, based at least in part on a predicted temporary change in the load requirements, the PCU can change its output voltage in anticipation of the temporary change in the load requirement, such as by increasing the output voltage to provide additional energy to the one or more variable loads during a temperoray increase in power consumption or by decreasing the output voltage during a temporary decrease in power consurription. The present invention proves particulary beneficial when employed to distribute power within a radar system.

Load controller and method to enhance effective capacity of a photovoltaic power supply using a dynamically determined expected peak loading

Abstract: A load controller and method are provided for maximizing effective capacity of a non-controllable, renewable power supply coupled to a variable electrical load also coupled to a conventional power grid. Effective capacity is enhanced by monitoring power output of the renewable supply and loading, and comparing the loading against the power output and a load adjustment threshold determined from an expected peak loading. A value for a load adjustment parameter is calculated by subtracting the renewable supply output and the load adjustment parameter from the current load. This value is then employed to control the variable load in an amount proportional to the value of the load control parameter when the parameter is within a predefined range. By so controlling the load, the effective capacity of the non-controllable, renewable power supply is increased without any attempt at operational feedback control of the renewable supply.

Power management system for variable load application

Abstract: A system and method for efficient distribution and conditioning of power to one or more variable loads are disclosed herein. Power having a first form is supplied to one or more power conversion units (PCUs) connected to the one or more variable loads. The PCUs are adapted to convert the power from the first form to other forms suitable for use by the components of the destination system. Additionally, a power control module is adapted to monitor the load requirements, both current and future, of the one or more variable loads. Based at least in part on the load requirements, the power control module controls the operation of the one or more PCUs to provide sufficient power to the one or more loads at the appropriate time while minimizing wasted power generation by deactivating any unnecessary PCUs. Additionally, the power control module can, based at least in part on a predicted temporary change in the load requirements, direct one or more of the PCUs to change their output voltages in anticipation of the change in the load requirement, such as by increasing their output voltages to provide additional energy to the one or more variable loads during a temporary increase in power consumption or by decreasing their output voltages during a temporary decrease in power consumption. The present invention proves particularly beneficial when employed to distribute power within a radar system.

Biopower Technical Assessment: State of the Industry and the Technology

Abstract: This report provides an assessment of the state of the biopower industry and the technology for producing electricity and heat from biomass. Biopower (biomass-to-electricity generation), a proven electricity generating option in the United States and with about 11 GW of installed capacity, is the single largest source of non-hydro renewable electricity. This 11 GW of capacity encompasses about 7.5 GW of forest product industry and agricultural industry residues, about 3.0 GW of municipal solid waste-based generating capacity and 0.5 GW of other capacity such as landfill gas based production. The electricity production from biomass is being used and is expected to continue to be used as base load power in the existing electrical distribution system. An overview of sector barriers to biopower technology development is examined in Chapter 2. The discussion begins with an analysis of technology barriers that must be overcome to achieve successful technology pathways leading to the commercialization of biomass conversion and feedstock technologies. Next, an examination of institutional barriers is presented which encompasses the underlying policies, regulations, market development, and education needed to ensure the success of biopower. Chapter 3 summarizes biomass feedstock resources, characteristics, availability, delivered prices, requirements for processing, and the impediments and barriersmore » to procurement. A discussion of lessons learned includes information on the California biomass energy industry, lessons from commercial biopower plants, lessons from selected DOE demonstration projects, and a short summary of the issues considered most critical for commercial success is presented in Chapter 4. A series of case studies, Chapter 5, have been performed on the three conversion routes for Combined Heat and Power (CHP) applications of biomass--direct combustion, gasification, and cofiring. The studies are based on technology characterizations developed by NREL and EPRI. Variables investigated include plant size and feed cost, and both cost of electricity and cost of steam are estimated using a discounted cash flow analysis. The economic basis for cost estimates is given. Environmental considerations are discussed in Chapter 6. Two primary issues that could create a tremendous opportunity for biomass are global warming and the implementation of Phase II of Title IV of the Clean Air Act Amendment of 1990 (CAAA). The environmental benefits of biomass technologies are among its greatest assets. Global warming is gaining greater salience in the scientific community and among the general population. Biomass use can play an essential role in reducing greenhouse gases, thus reducing the impact on the atmosphere. Cofiring biomass and fossil fuels and the use of integrated biomass gasification combined cycle systems can be an effective strategy for electric utilities to reduce their emissions of greenhouse gases. The final chapter reviews pertinent Federal government policies. U.S. government policies are used to advance energy strategies such as energy security and environmental quality. Many of the benefits of renewable energy are not captured in the traditional marketplace economics. Government policies are a means of converting non-economic benefits to an economic basis, often referred to as ''internalizing'' of ''externalities.'' This may be accomplished by supporting the research, development, and demonstration of new technologies that are not funded by industry because of projected high costs or long development time lines.« less

A power distribution/generation system

Abstract: A power distribution/generation system is disclosed for supplying electrical power to a number of sites (32, 33, 34), one or more of which has a generator (53, 1) such as a Stirling engine (1) which is capable of generating electrical power. The generators (53, 1) are linked together on a local network that is connectable to an external power grid (31). A controller (35) can hold the distribution of power so that a site is supplied with electrical power from the local network if its power demand exceeds the power generated by the generators in that network. However, if the total power demand of all the sites in the network exceeds the total power available from all the generators in that network, then the controller (35) causes power to be drawn from the grid (31) instead.

Supplying power to at least one electrical device based on an efficient operating point of a power supply

Abstract: A primary power supply and a secondary power supply are operable to supply power to at least one electrical device. A power demand of the electrical device is determined, and an efficient operating point for the primary power supply is determined. One or more of the primary power supply and the secondary power supply are used to supply power to the electrical device based on whether the primary power supply operating at an efficient operating point is operable to meet the power demand of the at least one electrical device.

Output Power Correlation Between Adjacent Wind Power Plants

Abstract: The National Renewable Energy Laboratory (NREL) started a project in 2000 to record long-term, high-frequency (1-Hz) wind power data from large commercial wind power plants in the Midwestern United States. Outputs from about 330 MW of installed wind generating capacity from wind power plants in Lake Benton, MN, and Storm Lake, Iowa, are being recorded. Analysis of the collected data shows that although very short-term wind power fluctuations are stochastic, the persistent nature of wind and the large number of turbines in a wind power plant tend to limit the magnitude of fluctuations and rate of change in wind power production. Analyses of power data confirms that spatial separation of turbines greatly reduces variations in their combined wind power output when compared to the output of a single wind power plant. Data show that high-frequency variations of wind power from two wind power plants 200 km apart are independent of each other, but low-frequency power changes can be highly correlated. This fact suggests that time-synchronized power data and meteorological data can aid in the development of statistical models for wind power forecasting.

Efficiency of HVAC power transmission from offshore-windmills to the grid

Abstract: For large offshore windparks far away from the coast, not only the investment costs of the transmission system but, moreover, the costs of the transmission losses play a decisive role for the economy of the total power system. In this paper some basic problems in determining the losses of HVAC transmission systems are discussed, taking into account the longitudinal distributions of current and temperature as well as the time-dependence of the power flow.

DER Benefits Analysis Studies: Final Report

Abstract: The electric power industry in the United States is undergoing dramatic change. Once totally controlled by utilities that had monopolistic holds on the supply, transmission and distribution of electricity in their service areas, the electric power system is being deregulated, introducing competition among electricity providers who can distinguish themselves by price, services and other factors. The new electric power system will feature advanced technologies and services that can be used on-site or located in close proximity to the load, instead of depending solely upon large, central station generation and transmission. Using a variety of advanced modular generating technologies (including small-scale renewables), distributed energy resource (DER) plants supply base-load power, peaking power, backup power, remote power and/or heating and cooling, and in some cases supply higher and more reliable quality power. Currently, DER represent a minor part of the electric supply system. If the potential of DER is to be realized in the new electric power market, a full understanding of the value and benefits these technologies provide to the electric system is necessary. This report includes 30 key quantitative studies reporting on the values and benefits of distributed energy generation technologies (including renewables) in various applications, as well as amore » matrix that permits key comparisons.« less

Thermal Power Plants in Turkey

Abstract: The objective of this article is to investigate the status of thermal power plants (TPPs) in Turkey as of the end of 2000. Thermal resources meet approximately 60% of Turkey’s total installed capacity for electric power generation, while 75% of total electricity is generated from TPPs. Of the total thermal generation, natural gas accounts for 49.2%, followed by coal for 40.65%, and 9.9% for liquid fuel. Nineteen TPPs belonging to the Turkish Electricity Generation and Transmission Cooperation (TEAS) and its affiliated partnership produce 74.6% of total electricity. Turkey’s average load factor is 61%, while the net unit generation cost is 4.19 cent/kWh. The availability of low-grade lignites in the country has led to the construction of lignite-fired TPPs. The use of coal, especially for power generation, is very essential to the continued economic growth of Turkey. However, advanced clean coal technologies should be considered for improving the environmental performance of coal combustion.

Generation reliability impacts of industry-owned distributed generation sources

Abstract: The successful integration of industry-owned distributed generation (DG) sources into the power systems of deregulated electric utilities involves fundamental long-term issues, conflicting objectives and important uncertainties. Presently, corporate financial difficulties, public environmental concern and deregulation of electric utility industry are making base load thermal and nuclear plants more and more difficult to build. As a result, industry-owned distributed generator is a source of electrical energy commonly considered as a part of the solution to this problem. Most of the available literature on DG has focused on its economic and interconnection impacts on a utility or on a ratepayer, or on an owner of distributed generating unit. What is missing from existing DG analysis is a relatively simple and understandable method examining the generation reliability impacts of industry-owned DG sources on utility systems. This paper presents industry schedule related models for modeling distributed generators for use in conventional generating capacity reliability assessment. The developed models are illustrated using the Institute of Electrical and Electronics Engineers (IEEE) Reliability Test System (RTS).

Power supply method

Abstract: PROBLEM TO BE SOLVED: To eliminate the use of a terminal in each house at the time of photovoltaic power generation and wind power generation, and enable the accurate prediction of a power generation amount based on climate information for each region for predicting the power generation amount for each region by means of the photovoltaic power generation and the wind power generation at a previous day and real time, by collecting climate information regarding sunshine and a wind force, and calculating an over-and-short power supply amount for each region at the previous day and the real time to indicate over-and-short electric energy for a power supply method for supplying power generated by using natural energy. SOLUTION: This method has a step for predicting natural energy for each region based on the climate information, a step for predicting a power generation amount by the power generation facility by taking a power generation facility in the region out of a prepared table based on the predicted natural energy, and a step for indicating a power generation amount predicted for each region. COPYRIGHT: (C)2005,JPO&NCIPI

European electricity market integration: the nordic experiences

Abstract: During the 1990s the electricity markets in Norway, Sweden, Finland and Denmark were deregulated and integrated into a single Nordic market for electricity. With consumption close to 400 TWh per annum the Nordic market is comparable to the largest national electricity markets in Europe. The purpose of this paper is to tentatively evaluate electricity market reform in the Nordic countries. In order to do this the development of wholesale and retail prices, peak and base load capacity and degree of competition (market power) between 1996 and 2002 is discussed. The main conclusions are that the wholesale markets are well integrated and reasonably efficient, while the retail markets remain national markets with different prices. Moreover, the new market institutions seem to handle large variations in hydropower supply quite efficiently, while peak load capacity is an emerging problem. Available information suggests that competition has induced substantial productivity increases in the power industry.

Evaluation of distribution analysis software for der applications

Abstract: The term ''Distributed energy resources'' or DER refers to a variety of compact, mostly self-contained power-generating technologies that can be combined with energy management and storage systems and used to improve the operation of the electricity distribution system, whether or not those technologies are connected to an electricity grid. Implementing DER can be as simple as installing a small electric generator to provide backup power at an electricity consumer's site. Or it can be a more complex system, highly integrated with the electricity grid and consisting of electricity generation, energy storage, and power management systems. DER devices provide opportunities for greater local control of electricity delivery and consumption. They also enable more efficient utilization of waste heat in combined cooling, heating and power (CHP) applications--boosting efficiency and lowering emissions. CHP systems can provide electricity, heat and hot water for industrial processes, space heating and cooling, refrigeration, and humidity control to improve indoor air quality. DER technologies are playing an increasingly important role in the nation's energy portfolio. They can be used to meet base load power, peaking power, backup power, remote power, power quality, as well as cooling and heating needs. DER systems, ranging in size and capacity from amore » few kilowatts up to 50 MW, can include a number of technologies (e.g., supply-side and demand-side) that can be located at or near the location where the energy is used. Information pertaining to DER technologies, application solutions, successful installations, etc., can be found at the U.S. Department of Energy's DER Internet site [1]. Market forces in the restructured electricity markets are making DER, both more common and more active in the distribution systems throughout the US [2]. If DER devices can be made even more competitive with central generation sources this trend will become unstoppable. In response, energy providers will be forced to both fully acknowledge the trend and plan for accommodating DER [3]. With bureaucratic barriers [4], lack of time/resources, tariffs, etc. still seen in certain regions of the country, changes still need to be made. Given continued technical advances in DER, the time is fast approaching when the industry, nation-wide, must not only accept DER freely but also provide or review in-depth technical assessments of how DER should be integrated into and managed throughout the distribution system. Characterization studies are needed to fully understand how both the utility system and DER devices themselves will respond to all reasonable events (e.g., grid disturbances, faults, rapid growth, diverse and multiple DER systems, large reactive loads). Some of this work has already begun as it relates to operation and control of DER [5] and microturbine performance characterization [6,7]. One of the most urgently needed tools that can provide these types of analyses is a distribution network analysis program in combination with models for various DER. Together, they can be used for (1) analyzing DER placement in distribution networks and (2) helping to ensure that adequate transmission reliability is maintained. Surveys of the market show products that represent a partial match to these needs; specifically, software that has been developed to plan electrical distribution systems and analyze reliability (in a near total absence of DER). The first part of this study (Sections 2 and 3 of the report) looks at a number of these software programs and provides both summary descriptions and comparisons. The second part of this study (Section 4 of the report) considers the suitability of these analysis tools for DER studies. It considers steady state modeling and assessment work performed by ORNL using one commercially available tool on feeder data provided by a southern utility. Appendix A provides a technical report on the results of this modeling effort.« less

Control of the Aero-Electric Power Station—an exciting QFT application for the 21st century

Abstract: The Aero-Electric Power Station is the ultimate solar power station, utilizing the dry, hot air of Earth's desert zones. By spraying water at the top of e.g. a 1200 m tall chimney with a diameter of 400 m, the air is cooled by evaporation and flows downwards through turbines at the bottom, generating 380 MW of net electric power. The Aero-Electric Power Station is still in the planning stage, and this paper belongs to a long series of feasibility studies. The current ‘truth’ model of the Aero-Electric Power Station is a one-dimensional partial differential equation model. The external slowly changing weather, defined as the mean air pressures, temperatures and humidity at the top and bottom of the tower, determines the optimal operating point, i.e. the optimal water spray flow and turbine velocity that give the largest net power. The gross power produced by the turbine is partly delivered to the grid and partly to pump sea water to spray water reservoirs. The reservoirs make it possible to use the pumping power and the spray flow rate as control. Wind changes cause significant deviations from the mean external air pressures, requiring closed loop regulation to keep the rotor velocity constant. The Aero-Electric Power Station may be modelled as an uncertain, unstable irrational transfer function, with two disturbances (external air pressure deviations at top and bottom), two control variables (turbine power and spray flow), and one output (rotor velocity), without a cascaded structure, giving rise to a robust load sharing control problem. A robust linear feedback regulator is designed by QFT, in such a way that the load of regulation is shared between the two control inputs. A closed loop step response simulation for one operating condition, using the ‘truth’ model, demonstrates the design. Copyright © 2003 John Wiley & Sons, Ltd.

Method of uprating an existing nuclear power plant

Abstract: An improved method of increasing the power output of an existing nuclear power plant includes increasing the thermal power output of the plant's nuclear island and constructing of an auxiliary BOP to handle the increased thermal power. The thermal power of the nuclear island can be increased such as by increasing the thermal power of the plant's reactor, by replacing the plant's steam generator with one that is more efficient, and by increasing the flow rate and/or change in temperature of a coolant in a secondary cooling loop of the plant. The thermal power of the reactor can be increased such as by replacing existing cylindrical fuel rods with fuel rods having a relatively greater surface area to volume ratio and/or by increasing the flow rate and/or the change in temperature of a coolant of a primary cooling loop. The auxiliary BOP can be constructed while the plant is in operation, and can then be connected with the nuclear island during a maintenance operation on the reactor.

Fuel cell power source

Abstract: A fuel cell power source (100) for use in electronic systems includes a fuel cell system (130) and a control means (150). The control means (150) computes net power requirements of a load device from one or more power functional information sources; and determines an operating point of the fuel cell system (130) by matching the net power requirements with the power characteristics of the fuel cell system (130).

Impact and limitation of wind power generation in an island power system

Abstract: The consequences of massive wind generation in a power system depend on many different parameters linked with the generation installation as well as with the power system they are connected with. In the case of island networks, this article presents an assessment method of the maximal admissible quantity of wind generation, regarding power system dynamic constraints. This wind power rate depends on several parameters, including load dynamic, operating rules and wind generator technology.

The effect of large offshore and onshore wind farms on the frequency of a national power supply system; simulation modelled on Germany

Abstract: The paper describes the simulated effect of large windfarms on the frequency of the interconnected grid system within which they are operating. The study is modelled on Germany. The features of the well-tested and widely used power system simulation package Power System Dynamics (PSD) were expanded so that windfarms with all commonly used wind turbine generators and their control structures can be simulated. In particular, the windfarm interaction with the power grid can be studied. Additionally, the effects of topology and wind conditions at the location of the wind turbines on the output power have been incorporated into the simulation. The result reveals that the stochastic nature of wind power at significant capacity may cause noticeable frequency fluctuation on the whole grid. Without countermeasures, the fluctuating power may use a disproportionately large component of the primary control power reserve of the grid system. The paper describes options for the integration of large offshore and onshore ...

Design support system for power supply system

Abstract: PROBLEM TO BE SOLVED: To provide a design support system for a power supply system that performs a support for designing an optimum combination of a generator set utilizing natural energy such as sunlight, wind power and wave power. SOLUTION: A power supply system model is constituted by selecting a variety of the generating sets with natural energy as drive sources, a power consumption apparatus model is constituted by inputting the power consumption of a variety of power consumption apparatuses installed at environmental plant facilities, a predicted output power rate at each hourly zone of one day at the power supply system model is calculated with atmospheric data of a target region wherein the environmental plant facilities are installed, as an input, the transition of the predicted output power rate of the one day is graphed and indicated, a scheduled power consumption rate at each hourly zone of the one day at the power consumption apparatus model is calculated with an operating time for which each power consumption apparatus of the power consumption apparatus model operates at each hourly zone of the one day, and the scheduled power consumption rate of the one day is graphed and indicated. COPYRIGHT: (C)2005,JPO&NCIPI

The power of time.

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Method of operating a nuclear power plant at multiple power levels

Abstract: A method of operating a nuclear power plant includes determining and licensing a maximum power level at which the power plant can be operated subsequent to the beginning of a fuel cycle, and with the power plant being operated at less than its maximum power rating at certain times such as at the beginning of a fuel cycle. The maximum power level is greater than the power level that would be calculated based upon an assumption that the heat flux peaking factor (F Q ) and enthalpy rise peaking factor (F ΔH ) remain at their maximum level throughout an entire fuel cycle. The maximum power rating takes advantage of factors such as known reductions in F Q and F ΔH at certain points in the fuel cycle, the marginal additional capacity of the Balance Of Plant, and the occasional optimization of process parameters such as ultimate heat sink temperature and atmospheric conditions. The power plant may be operated at a substantially continuously variable power level based upon various factors of the power plant, but would not exceed the NRC licensed core thermal power level.

Method for operating an energy storing energy generating plant

Abstract: The invention relates to a storage power station (S), for example an air storage plant, comprising a compressor unit (V), a turbine unit (T), and a storage volume (100). Said storage power station is operated according to a special mode of operation which enables it to react as quickly as possible to changes in the load requirements. According to the invention, rapid changes in the load requirements are compensated by regulating the power absorption of the compressor unit (V), resulting in a variable net power output at the same time as a constant power output of the turbine unit (T). The power of the compressor unit can be regulated faster than a regulation of the power engine, by approximately one order of magnitude. In extreme cases, the compressor unit can be simply switched off, whereby within seconds the drive power thereof is released for an electricity network. The turbine unit can meanwhile continue to be normally operated and slowly follow the power requirement, reducing the load on the turbine. A storage power station operated according to the invention is outstandingly suitable for frequency support and for covering rapid load ramps in an electricity network.

Designing controls to increase wind power penetration in weakly connected areas of the Hellenic interconnected system

Abstract: Penetration of wind power into weak transmission grids faces specific difficulties due to security constraints. The major issue is the capability of existing transmission grids to securely absorb the wind power. This paper presents some ideas in order to increase the wind power penetration into weak networks by applying new control concepts. It also presents a methodology to assess the impact of the proposed techniques to the wind penetration achieved. The proposed rule is based on the control of the power flow from the windy area through a weak corridor.

Power feeding system of fuel cell

Abstract: PROBLEM TO BE SOLVED: To provide a power feeding system of a fuel cell for keeping correspondences to load variations, and in addition, protecting a power storage means from over discharge SOLUTION: The system comprises two power storage means 10, 12 connected to a fuel cell 1 and a load 4 in an openable/closable manner, and a circuit opening/closing means 13-16 for enabling switching a state that one power storage means 10 or 12 is connected to the fuel cell 1 and not connected to the load 4 and also other power storage means 10 or 12 is not connected to the fuel cell 1 and connected to the load 4 to a state that, on the contrary, one power storage means 10 or 12 is not connected to the fuel cell 1 and connected to the load 4 and also other power storage means 10 or 12 is connected to the fuel cell 1 and not connected to the load 4 Therefore, the power generated by the fuel cell 1 is exclusively fed for the charge of the power storage means 10, 12, the burden on the load variations of the fuel cell 1 can be reduced, the power feeding to the load 4 is performed from the power storage means 10, 12, and the system can correspond to the load variations within the ability ranges of the power storage means 10, 12 COPYRIGHT: (C)2004,JPO&NCIPI

Wind generator control in compliance with new norms

Abstract: The level of wind penetration in the total generated electrical energy in Germany is increasing in such a way that new norms for connecting wind power stations to the electric power system are prescribed by the power companies. Windmills are no longer to be seen as "negative" consumers but rather as conventional power stations. This means that wind power stations in the near future must fulfill requirements like supporting the mains supply during faults, controlling reactive power and limiting transient currents at start-up. Brazil is setting a very good example by complying with the Kyoto protocol and its government program for supporting the construction of wind farms. With its potential and the commitment of the new administration in further developing the implantation of renewable energy sources these advances happening in countries like Germany, where the wind energy has achieved such development level, have to be taken into account to guarantee power quality in the future. This work presents a control scheme for a doubly fed induction generator in windmills focusing on power flow optimisation. By controlling reactive power system losses are minimised and other goals are also achieved in meeting the requirements of the new generation of wind power stations.