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Preliminary results from flight measurements in gradual-turn maneuvers of the wing loads and the distribution of load among the components of a Boeing B-47A airplane

Description: Report presenting an analysis of some strain-gage measurements of the loads carried by the wing and horizontal tail of a Boeing B-47A airplane during gradual-turn maneuvers for a variety of altitudes and Mach numbers. Results regarding the wing-load center of pressure, component loads, component-force coefficients, and fraction of the wing-fuselage load carried by the wing are provided.
Date: June 27, 1955
Creator: Cooney, T. V.; Andrews, William H. & McGowan, William A.
Partner: UNT Libraries Government Documents Department

Pacific Northwest GridWise™ Testbed Demonstration Projects; Part II. Grid Friendly™ Appliance Project

Description: Fifty residential electric water heaters and 150 new residential clothes dryers were modified to respond to signals received from underfrequency, load-shedding appliance controllers. Each controller monitored the power-grid voltage signal and requested that electrical load be shed by its appliance whenever electric power-grid frequency fell below 59.95 Hz. The controllers and their appliances were installed and monitored for more than a year at residential sites at three locations in Washington and Oregon. The controllers and their appliances responded reliably to each shallow underfrequency event—an average of one event per day—and shed their loads for the durations of these events. Appliance owners reported that the appliance responses were unnoticed and caused little or no inconvenience for the homes’ occupants.
Date: October 1, 2007
Creator: Hammerstrom, Donald J.; Brous, Jerry; Chassin, David P.; Horst, Gale R.; Kajfasz, Robert; Michie, Preston et al.
Partner: UNT Libraries Government Documents Department

Ancillary-service details: regulation, load following, and generator response

Description: The purpose of this report is to examine empirically these intrahour and interhour load changes and the responses of a utility`s generating resources to those load changes. We analyze data, primarily from one control area, to see how it maintains ACE close to zero in an effort to meet the A1 and A2 criteria. Overall, we estimate that load following costs US electric utilities over one billion dollars a year. We first test alternative ways to identify trends over multihour periods using both regression analysis and rolling averages. Then, we consider several metrics for intrahour load following. Next we examine characteristics of load following for different time-averaging periods and compare the dynamics of loads and load following generation across these time periods. Finally, we consider the contribution of each load to the total load following requirements of the control area.
Date: September 1, 1996
Creator: Hirst, E. & Kirby, B.
Partner: UNT Libraries Government Documents Department

Development and application of a high-speed, high-resolution data acquisition system for monitoring power at the service entrance to buildings

Description: A non-intrusive load monitoring system (NILMS) was developed and tested to determine its capabilities and examine ways that the system can supplement the understanding of how energy is used in a building. The investigation of the system as a method for obtaining short-term building energy use and demand data faster, as less cost, with less complexity, and less intrusively than from conventional submetering is described in this report. Data acquisition hardware and software, a power transducer, and current transformers were assembled into a system that could be used to sample the instantaneous real and reactive power coming into a building. The system was used to collect power profiles at a commercial and a residential building. The NILMS can sample power at low speeds (one sample per hour or less) and at speeds exceeding 100 Hz. Large changes in building power such as those due to central heating and cooling systems, water heaters, or banks of lights can easily be discriminated from total building power profiles collected by the system. Smaller loads, less than 1 or 2 kW, can be resolved when there is little ``noise`` in the power profile. Very small loads, less than 100 W, can be resolved in a residential application. Resolution becomes more difficult as larger and more frequent fluctuations occur. The ability of the system to easily collect valuable, short-term building power profiles, which permit individual loads to be determined (resolved), makes the system attractive for a number of applications. The system could prove very useful for measuring short-term energy use and demand, assisting building energy auditors in assessing building deficiencies, providing short-term performance data for validating engineering-based savings estimates and calibrating computer-based building performance models, and for validating, developing, and/or improving building and building system operating strategies.
Date: February 1, 1995
Creator: Sharp, T.R.
Partner: UNT Libraries Government Documents Department

Defining intra- and interhour load swings

Description: Electricity consumption varies with time. These temporal variations include moment-to-moment fluctuations plus hour-to-hour changes associated with diurnal, weekly, and seasonal patterns. The problem naturally splits into two time frames: (1) fast fluctuations, on the order of seconds to minutes, and (2) slower fluctuations, on the order of an hour or longer. Fast fluctuations in aggregate load result primarily from the random movements of individual loads. Slower fluctuations result from common external causes, such as time of day, day of the week, and weather. This study empirically examines intra- and interhour load following. It develops methods to separate intra- and interhour load fluctuations, identifies the key features of each, and shows how they differ from each other.
Date: September 1, 1996
Creator: Hirst, E. & Kirby, B.
Partner: UNT Libraries Government Documents Department

Load flow analysis: Base cases, data, diagrams, and results

Description: This report describes how an electric utility system is modeled by using load flow techniques to establish a validated power flow case suitable for simulating and evaluating alternative system scenarios. Details of the load flow model are supported by additional technical and descriptive information intended to correlate modeled electrical system parameters with the corresponding physical equipment that makes up the system. Pictures and technical specifications of system equipment from the utility, public, or vendor are provided to support this association for many system components. The report summarizes the load flow model construction, simulation, and validation and describes the general capabilities of an information query system designed to access load flow parameters and other electrical system information.
Date: October 1, 1997
Creator: Portante, E. C.; Kavicky, J. A.; VanKuiken, J. C. & Peerenboom, J. P.
Partner: UNT Libraries Government Documents Department

Non-intrusive submetering of residential gas appliances

Description: A new technique was developed to non-intrusively monitor the use of individual gas appliances in homes. It relied on a very sensitive master gas meter equipped with a pulse meter, data logger, and software. The procedure involves two steps: decomposition and identification of the end uses. The technique is about 95% accurate but the algorithms can still be confused by some relatively common situations. Further improvements in the software are expected to improve accuracy. The procedure was applied to over 600 homes in Tokyo, Japan. The aggregate data allow more accurate estimates of energy consumption by the major residential gas appliances in addition to their hourly load profiles. Key factors affecting energy demand by each gas appliance were obtained by combining the energy and demographic data. These data are essential for more accurate forecasting of gas consumption, system sizing, and other marketing activities. The system will not necessarily be as successful in America due to the presence of pilot lights, more appliances per household, and variable-rate gas appliances. Nevertheless, the approach appears promising because it is economical and accurate.
Date: August 1, 1996
Creator: Yamagami, Shin; Nakamura, Hajime & Meier, A.
Partner: UNT Libraries Government Documents Department

Ancillary-service details: Dynamic scheduling

Description: Dynamic scheduling (DS) is the electronic transfer from one control area to another of the time-varying electricity consumption associated with a load or the time-varying electricity production associated with a generator. Although electric utilities have been using this technique for at least two decades, its use is growing in popularity and importance. This growth is a consequence of the major changes under way in US bulk-power markets, in particular efforts to unbundle generation from transmission and to increase competition among generation providers. DS can promote competition and increase choices. It allows consumers to purchase certain services from entities outside their physical-host area and it allows generators to sell certain services to entities other than their physical host. These services include regulation (following minute-to-minute variations in load) and operating reserves, among others. Such an increase in the number of possible suppliers and customers should encourage innovation and reduce the costs and prices of providing electricity services. The purpose of the project reported here was to collect and analyze data on utility experiences with DS. Chapter 2 provides additional details and examples of the definitions of DS. Chapter 3 explains why DS might be an attractive service that customers and generators, as well as transmission providers, might wan to use. Chapter 4 presents some of the many current DS examples the authors uncovered in their interviews. Chapter 5 discusses the costs and cost-effectiveness of DS. Chapter 6 explains what they believe can and cannot be electronically moved from one control area to another, primarily in terms of the six ancillary services that FERC defined in Order 888. Chapter 7 discusses the need for additional research on DS.
Date: January 1, 1997
Creator: Hirst, E. & Kirby, B.
Partner: UNT Libraries Government Documents Department

Computer-specific metrics for the regulation and load following ancillary services

Description: In competitive electricity markets, the costs for each ancillary service should be charged to those who cause the costs to be incurred with charges based on the factors that contribute to these costs. For example, the amount of generating capacity assigned to the regulation service is a function of the short-term volatility of system load. Therefore, the charges for regulation should be related to the volatility of each load, not to its average demand. This report discusses the economic efficiency and equity benefits of assessing charges on the basis of customer-specific costs (rather than the traditional billing determinants, MWh or MW), focusing on two key real-power ancillary services, regulation and load following. The authors determine the extent to which individual customers and groups of customers contribute to the system's generation requirements for these two services. In particular, they analyze load data to determine whether some customers account for shares of these two services that differ substantially from their shares of total electricity consumption.
Date: January 1, 2000
Creator: Kirby, B. & Hirst, E.
Partner: UNT Libraries Government Documents Department

Sandia Smart Anti-Islanding Project; Summer 2001: Task II Investigation of the Impact of Single-Phase Induction Machines in Islanded Loads: Summary of Results

Description: Islanding, the supply of energy to a disconnected portion of the grid, is a phenomenon that could result in personnel hazard, interfere with reclosure, or damage hardware. Considerable effort has been expended on the development of IEEE 929, a document that defines unacceptable islanding and a method for evaluating energy sources. The worst expected loads for an islanded inverter are defined in IEEE 929 as being composed of passive resistance, inductance, and capacitance. However, a controversy continues concerning the possibility that a capacitively compensated, single-phase induction motor with a very lightly damped mechanical load having a large rotational inertia would be a significantly more difficult load to shed during an island. This report documents the result of a study that shows such a motor is not a more severe case, simply a special case of the RLC network.
Date: May 1, 2002
Creator: ROPP, MIKE; BONN, RUSSELL H.; GONZALEZ, SIGIFREDO & WHITAKER, CHUCK
Partner: UNT Libraries Government Documents Department

Deemed Savings Estimates for Legacy Air Conditioning and WaterHeating Direct Load Control Programs in PJM Region

Description: During 2005 and 2006, the PJM Interconnection (PJM) Load Analysis Subcommittee (LAS) examined ways to reduce the costs and improve the effectiveness of its existing measurement and verification (M&V) protocols for Direct Load Control (DLC) programs. The current M&V protocol requires that a PURPA-compliant Load Research study be conducted every five years for each Load-Serving Entity (LSE). The current M&V protocol is expensive to implement and administer particularly for mature load control programs, some of which are marginally cost-effective. There was growing evidence that some LSEs were mothballing or dropping their DLC programs in lieu of incurring the expense associated with the M&V. This project had several objectives: (1) examine the potential for developing deemed savings estimates acceptable to PJM for legacy air conditioning and water heating DLC programs, and (2) explore the development of a collaborative, regional, consensus-based approach for conducting monitoring and verification of load reductions for emerging load management technologies for customers that do not have interval metering capability.
Date: March 1, 2007
Creator: Goldman, Charles
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Lower Cleanroom Roof Quick Load Analysis

Description: This engineering note documents calculations done to determine the margin of safety for the lower clean room roof. The analysis was done to give me a feeling of what the loads, stresses and capacity of the roof is prior to installation and installation work to be done for the helium refrigerator upgrade. The result of this quick look showed that the calculated loads produce stress values and loads at about half the allowables. Based on this result, I do not think that special precautions above personal judgement are required for the installation work.
Date: November 17, 1995
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

Generator response to intrahour load fluctuations

Description: Although system loads fluctuate rapidly and are typically measured at 2-second intervals by utility control centers, generation does not track these high-speed fluctuations. Analysis of data from a large Midwestern control area shows that generation tracks load at roughly the 1- to 2-minute level. In addition, some of the generating units assigned to this regulation service actually contribute to the regulating burden.
Date: September 1, 1996
Creator: Kirby, B. & Hirst, E.
Partner: UNT Libraries Government Documents Department

Energy use of televisions and video cassette recorders in the U.S.

Description: In an effort to more accurately determine nationwide energy consumption, the U.S. Department of Energy has recently commissioned studies with the goal of improving its understanding of the energy use of appliances in the miscellaneous end-use category. This study presents an estimate of the residential energy consumption of two of the most common domestic appliances in the miscellaneous end-use category: color televisions (TVs) and video cassette recorders (VCRs). The authors used a bottom-up approach in estimating national TV and VCR energy consumption. First, they obtained estimates of stock and usage from national surveys, while TV and VCR power measurements and other data were recorded at repair and retail shops. Industry-supplied shipment and sales distributions were then used to minimize bias in the power measurement samples. To estimate national TV and VCR energy consumption values, ranges of power draw and mode usage were created to represent situations in homes with more than one unit. Average energy use values for homes with one unit, two units, etc. were calculated and summed to provide estimates of total national TV and VCR energy consumption.
Date: March 1, 1999
Creator: Meier, Alan & Rosen, Karen
Partner: UNT Libraries Government Documents Department

Resource planning for gas utilities: Using a model to analyze pivotal issues

Description: With the advent of wellhead price decontrols that began in the late 1970s and the development of open access pipelines in the 1980s and 90s, gas local distribution companies (LDCs) now have increased responsibility for their gas supplies and face an increasingly complex array of supply and capacity choices. Heretofore this responsibility had been share with the interstate pipelines that provide bundled firm gas supplies. Moreover, gas supply an deliverability (capacity) options have multiplied as the pipeline network becomes increasing interconnected and as new storage projects are developed. There is now a fully-functioning financial market for commodity price hedging instruments and, on interstate Pipelines, secondary market (called capacity release) now exists. As a result of these changes in the natural gas industry, interest in resource planning and computer modeling tools for LDCs is increasing. Although in some ways the planning time horizon has become shorter for the gas LDC, the responsibility conferred to the LDC and complexity of the planning problem has increased. We examine current gas resource planning issues in the wake of the Federal Energy Regulatory Commission`s (FERC) Order 636. Our goal is twofold: (1) to illustrate the types of resource planning methods and models used in the industry and (2) to illustrate some of the key tradeoffs among types of resources, reliability, and system costs. To assist us, we utilize a commercially-available dispatch and resource planning model and examine four types of resource planning problems: the evaluation of new storage resources, the evaluation of buyback contracts, the computation of avoided costs, and the optimal tradeoff between reliability and system costs. To make the illustration of methods meaningful yet tractable, we developed a prototype LDC and used it for the majority of our analysis.
Date: November 1, 1995
Creator: Busch, J.F. & Comnes, G.A.
Partner: UNT Libraries Government Documents Department

Behavior of Capstone and Honeywell microturbine generators during load changes

Description: This report describes test measurements of the behavior of two microturbine generators (MTGs) under transient conditions. The tests were conducted under three different operating conditions: grid-connect; stand-alone single MTG with load banks; and two MTGs running in parallel with load banks. Tests were conducted with both the Capstone 30-kW and Honeywell Parallon 75-kW MTGs. All tests were conducted at the Southern California Edison /University of California, Irvine (UCI) test facility. In the grid-connected mode, several test runs were conducted with different set-point changes both up and down and a start up and shutdown were recorded for each MTG. For the stand-alone mode, load changes were initiated by changing load-bank values (both watts and VARs). For the parallel mode, tests involved changes in the load-bank settings as well as changes in the power set point of the MTG running in grid-connect mode. Detailed graphs of the test results are presented. It should be noted that these tests were done using a specific hardware and software configuration. Use of different software and hardware could result in different performance characteristics for the same units.
Date: July 1, 2001
Creator: Yinger, Robert J.
Partner: UNT Libraries Government Documents Department

HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT SUMMARY OF COMBINED THERMAL & OPERATING LOADS

Description: This report summarizes the results of the Double-Shell Tank Thermal and Operating Loads Analysis (TOLA) combined with the Seismic Analysis. This combined analysis provides a thorough, defensible, and documented analysis that will become a part of the overall analysis of record for the Hanford double-shell tanks (DSTs).
Date: March 17, 2006
Creator: MACKEY, T.C.
Partner: UNT Libraries Government Documents Department

Direct Drive Wave Energy Buoy – Intermediate scale experiment

Description: Columbia Power Technologies deployed a scaled prototype wave energy converter (WEC) in the Puget Sound in February 2011. Other than a brief period (10 days) in which the WEC was removed for repair, it was in the water from Feb. 15, 2011 until Mar. 21, 2012. The SeaRay, as this WEC is known, consists of three rigid bodies which are constrained to move in a total of eight degrees of freedom (DOF). The SeaRay is kept on station with a spread, three-point mooring system. This prototype WEC is heavily instrumented, including but not limited to torque transducers and encoders reporting generator torque applied to and relative pitch of the floats, an inertial measurement unit (IMU) reporting translational acceleration and rotational position of the spar/nacelle, a GPS sensor reporting position, load cells reporting mooring loads at the WEC connection points and a number of strain gauges embedded in the fiberglass reinforced plastic (FRP) hull. Additionally, wave and current data are collected using an Acoustic Wave And Current Profiler (AWAC), allowing performance and design data to be correlated to environmental input conditions. This data – quality controlled, processed and analyzed – is used to characterize the metocean conditions (i.e. sea states). The WEC response will be correlated to the metocean conditions. These results will primarily be used to validate numerical models. The validated numerical models will be used optimize the commercial scale WEC and inform the design process. This document details the SeaRay experiment, including the quality control, processing and subsequent analysis of the data. Furthermore, the methodology and the results of numerical model validation will be described.
Date: July 29, 2013
Creator: Rhinefrank, Kenneth E.; Lenee-Bluhm, Pukha; Prudell, Joseph H.; Schacher, Alphonse A.; Hammagren, Erik J. & Zhang, Zhe
Partner: UNT Libraries Government Documents Department

The Role of Demand Resources In Regional Transmission Expansion Planning and Reliable Operations

Description: Investigating the role of demand resources in regional transmission planning has provided mixed results. On one hand there are only a few projects where demand response has been used as an explicit alternative to transmission enhancement. On the other hand there is a fair amount of demand response in the form of energy efficiency, peak reduction, emergency load shedding, and (recently) demand providing ancillary services. All of this demand response reduces the need for transmission enhancements. Demand response capability is typically (but not always) factored into transmission planning as a reduction in the load which must be served. In that sense demand response is utilized as an alternative to transmission expansion. Much more demand response is used (involuntarily) as load shedding under extreme conditions to prevent cascading blackouts. The amount of additional transmission and generation that would be required to provide the current level of reliability if load shedding were not available is difficult to imagine and would be impractical to build. In a very real sense demand response solutions are equitably treated in every region - when proposed, demand response projects are evaluated against existing reliability and economic criteria. The regional councils, RTOs, and ISOs identify needs. Others propose transmission, generation, or responsive load based solutions. Few demand response projects get included in transmission enhancement plans because few are proposed. But this is only part of the story. Several factors are responsible for the current very low use of demand response as a transmission enhancement alternative. First, while the generation, transmission, and load business sectors each deal with essentially the same amount of electric power, generation and transmission companies are explicitly in the electric power business but electricity is not the primary business focus of most loads. This changes the institutional focus of each sector. Second, market and reliability ...
Date: July 1, 2006
Creator: Kirby, Brendan J.
Partner: UNT Libraries Government Documents Department

1994 Pacific Northwest Loads and Resources Study, Technical Appendix: Volume 1.

Description: The 1994 Pacific Northwest Loads and Resources Study establishes the Bonneville Power Administration`s (BPA) planning basis for supplying electricity t6 BPA customers. The Loads and Resources Study is presented in two documents: (1) this technical appendix detailing loads and resources for each major Pacific Northwest generating utility; and (2) a summary of Federal system and Pacific Northwest region loads and resources. This analysis updates the 1993 Pacific Northwest Loads and Resources Study Technical Appendix published in December 1993. This technical appendix provides utility specific information that BPA uses in its long-range planning. It incorporates the following for each utility: (1) electrical demand-firm loads; (2) generating resources; and (3) contracts both inside and outside the region. This document should be used in combination with the 1994 Pacific Northwest Loads and Resources Study, published in December 1994, because much of the information in that document is not duplicated here. This BPA planning document incorporates Pacific Northwest generating resources and the 1994 medium load forecast prepared by BPA. Each utility`s forecasted future firm loads are subtracted from its existing resources to determine whether it will be surplus or deficit. If a utility`s resources are greater than loads in any particular year or month, there is a surplus of energy and/or capacity, which the utility can sell to increase revenues. Conversely, if its firm loads exceed available resources, there is a deficit of energy and/or capacity, and additional conservation, contract purchases, or generating resources will be needed to meet the utility`s load.
Date: December 1, 1994
Creator: United States. Bonneville Power Administration.
Partner: UNT Libraries Government Documents Department

Evaluation of Islanding Detection Methods for Utility-Interactive Inverters in Photovoltaic Systems

Description: This report describes the various methods and circuits that have been developed to detect an islanding condition for photovoltaic applications and presents three methods that have been developed to test those methods and circuits. Passive methods for detecting an islanding condition basically monitor parameters such as voltage and frequency and/or their characteristics and cause the inverter to cease converting power when there is sufficient transition from normal specified conditions. Active methods for detecting the island introduce deliberate changes or disturbances to the connected circuit and then monitor the response to determine if the utility grid with its stable frequency, voltage and impedance is still connected. If the small perturbation is able to affect the parameters of the load connection within prescribed requirements, the active circuit causes the inverter to cease power conversion and delivery of power to the loads. The methods not resident in the inverter are generally controlled by the utility or have communications between the inverter and the utility to affect an inverter shut down when necessary. This report also describes several test methods that may be used for determining whether the anti-islanding method is effective. The test circuits and methodologies used in the U.S. have been chosen to limit the number of tests by measuring the reaction of a single or small number of inverters under a set of consensus-based worst-case conditions.
Date: November 1, 2002
Creator: BOWER, WARD I. & ROPP, MICHAEL
Partner: UNT Libraries Government Documents Department