663,212 research outputs found
Geothermal Power Generation as Related to Resource Requirements
No full textFor the past several years geothermal exploratory work has been conducted in northern Nevada. In conjunction with that effort a proposed 55-MW steam geothermal power plant was considered for initial installation in one of the fields being developed. The characteristics of the geothermal fields under consideration were not firm, with data indicating widely varying downhole temperatures. Thus, neither the resource nor the plant operating conditions could be set. To assist both the ultimate user of the resource, the utility, and the developer of the geothermal field, a series of parametric sensitivity studies were conducted for the initial evaluation of a field vis-a-vis the power plant. Using downhole temperature as the variable, the amount of brine, brine requirements/kWh, and pounds brine/pound of steam to the turbine were ascertained. This was done over a range of downhole temperatures of from 350F to 475F.
The studies illustrate the total interdependence of the geothermal resource and its associated power plant. The selection of geothermal steam power plant design conditions must be related to the field in which the plant is located. The results of the work have proven to be valuable in two major respects: (1) to determine the production required of a particular geothermal field to meet electrical generation output and (2) as field characteristics become firm, operating conditions can be defined for the associated power plant
Effects of power electronic compensation on distribution network thermal and voltage violations
No full textThis paper is concerned with the use of medium-voltage power electronics in providing active compensation to distribution networks. The primary purpose of using active compensation is to allow for network growth in the form of distributed generation or customer demand increases. With continuing growth, network thermal and voltage constraints would eventually be violated at some point, even with the use of power electronic compensation. Through the study of increasing generation on several hundred distribution network datasets, trends in the type and location of these constraint breaches are identified for both uncompensated and compensated networks. In comparing the initial types of constraint breaches in uncompensated and compensated networks, the use of power electronics is seen to eliminate overvoltage issues as the primary concern in many cases. In addition, while power electronic compensation is seen to make a significant change in the growth accommodated before constraint breach, the location of these initial breaches is not altered appreciably
Power Conditioning and Control Applications for Energy Conservation
No full textElectrical power conditioning and control (PCC) systems are finding cost effective applications in AC motor drives, lamp ballasts and power supplies. Substantial system efficiency improvements are being realized when the appropriate PCC system is coupled to an existing process. Improvements made in fabricating power semiconductors, increased power handling capabilities and advanced circuit designs will continue to reduce the cost per watt of service. Three generic PCC systems were identified as possessing significant potential for energy conserving applications: switching power supplies, high frequency ballasts and AC synthesizers. On a national basis, it was estimated that industry could conserve 8.5, 42.2, 109.7 terawatt-hrs. (1012 watt-hrs.) of electricity in the years 1985, 1990, and 2000 respectively, based on conservative penetration scenarios
Benefits of distribution-level power electronics for supporting distributed generation growth
No full textIt is expected that distribution networks will be required to accommodate large amounts of distributed generation (DG). Keeping power flows and voltages within their limits will require either traditional infrastructure upgrades or active compensation. The form of active compensation (e.g., series, shunt, back to back, multiterminal), quantity, and rating of the compensator should be chosen to realize the best cost-benefit ratio. Distributed-generator and compensator placement algorithms are used with a power-flow and constraint satisfaction algorithm to analyze a large number of case studies (using real U.K. network data). From these cases, assessments of compensator performance are made and summarized statistically. When considering incremental deployment across all networks, with the site of greatest benefit chosen at each increment, it is found that static synchronous compensators provide the most favorable cost-benefit ratio. In contrast, multiterminal voltage-source converters tend to provide the greatest flexibility when considering uniform deployment across all networks. It is also observed that traditional reinforcement enhances the benefits provided by active compensation
Battery Storage System as Power Unbalance Redistributor in Distribution Grids Based on Three Legs Four Wire Voltage Source Converter
No full textThis article discusses the application of battery energy storage systems (BESSs) as power redistributors in three-phase distribution grids as an add-on functionality to typical BESS applications, such as congestion management and energy arbitrage. Combining those ancillary services into a single power unit is not yet performed in practice but may constitute an emerging business opportunity to increase the BESS revenues. The unbalanced operation of the BESS voltage source converter (VSC) leads to the circulation of low-frequency current harmonics in the dc-link through the capacitors and the battery cells. Therefore, it is particularly interesting whether relatively large 50- and 100-Hz currents can safely circulate within these components. Analytical modeling and design guidelines for the dc-link of a three-leg four-wire two-level VSC operating under unbalanced loads are detailed. Furthermore, a low-power VSC prototype is used to demonstrate the working principle of the BESS, providing power unbalance redistribution and symmetric power exchange. Additionally, the ICR18650-26F Lithium-ion cells are cycled to reach end-of-life with different current profiles and C-ratings. The analysis shows that charging with a 100 Hz ripple superimposed to the dc current leads to a 10% increment in degradation
Oil to Coal Conversion of Power and Industrial Facilities in the Dominican Republic
No full textRealizing that the use of coal has the potential to offset the effects of world oil prices on the Dominican Republic's economy, the Commission Nacional de Politica Energetica (CNPE) requested Bechtel Power Corporation to study the technical and economic feasibility of converting the nation's largest oil-fired facilities to coal and to develop preliminary designs for the conversions.
This paper addresses the methodology used in the study, with special emphasis on the determination of the technical and economic feasibility of converting power plants and cement plants from oil to coal. The summary results and conclusions are presented and include coal conversion capital costs, cost savings, and program overall schedule. The intent of the authors is to provide a reference for the study of converting other islands' oil burning facilities to coal
Improved system operations with high penetration of wind power : a dialog between academia and industry - Ireland
No full textPanel session submission for the IEEE Power and Energy Society (PES) 2010 General Meeting, July 25-29 2010, Minneapolis, MinnesotaThis is a submission to a panel session at the 2010
IEEE PES General Meeting. It discusses effective collaboration
between academia and industry.Science Foundation IrelandConference websitehttp://ewh.ieee.org/conf/pesgm10/Charles Parsons Energy Research AwardsCharles Parso
Impact of wind power on the unit commitment, operating reserves and market design
No full textPaper presented at the 2011 IEEE Power and Energy Society General Meeting, San Diego, CA, 24-29 July 2011This article highlights and demonstrates the new requirements variable and partly unpredictable wind power will bring to unit commitment and power system operations.
Current practice is described and contrasted against the new requirements. Literature specifically addressing questions about wind power and unit commitment related power system operations is surveyed. The scope includes forecast errors, operating reserves, intra-day markets, and sharing reserves across interconnections. The discussion covers the critical issues arising from the research.Science Foundation Irelandau, ti, ke, ab, co - TS 10.04.1
Load Management and Houston Lighting and Power Co.
No full textDefining Load Management as influencing of customer loads in order to shift the time use of electric power and energy, encompasses a broad spectrum of activities at Houston Lighting & Power Company. This paper describes those activities by directing them into four categories:
1. Inherent (Things that are inherent to our rates or metering practices)
2. Emergency (Programs used as part of our Emergency Curtailment Plan)
3. Supply Management (Acting on utility side of meter)
4. Current Programs (Developing the more traditional LM Programs)
To emphasize the areas of interest to the Industrial class customer, a review of activities applicable in this area is discussed covering:
1. Peak Shave Service
2. Interruptible Service A
3. Interruptible Service B
4. Conservation (As it pertains to the Industrial)
5. Co-Generatio
Reducing passive filter sizes with tuned traps for distribution level power electronics
No full textThis paper proposes a filter topology intended for use with medium voltage grid-interfaced power electronics as an alternative to the widely-utilized LCL filter topology. The proposed topology utilizes multiple shunt RLC trap filters with parameters optimized to minimize the overall size of the filter while meeting performance requirements for connection to the distribution grid. Results indicate a potential for reduction of twenty-five to thirty percent in total filter volume for the scenario studied. In addition, total power losses taking place within the filter are slightly reduced
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