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1

Study of abnormal combustion oscillations in gas fired appliances.  

E-Print Network (OSTI)

??The thesis work discusses abnormal combustion noise in gas-fired appliances. An experimental model was made to provide insight into the causes of abnormal combustion noises.… (more)

Kumar, Dasari

2006-01-01T23:59:59.000Z

2

Monte Carlo Potts Investigation of Dynamic Abnormal Grain Growth  

Science Conference Proceedings (OSTI)

A behavior akin to dynamic abnormal grain growth has been found to occur in model results using small strain rates to achieve modest recrystallization rates.

3

Surveillance Guide - OPS 9.6 Investigation of Abnormal Events  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

INVESTIGATION OF ABNORMAL EVENTS INVESTIGATION OF ABNORMAL EVENTS 1.0 Objective The objective of this surveillance is to verify that contractor personnel are effectively investigating abnormal events. The activities included in this surveillance provide a basis for determining whether the contractor has implemented a thorough review process to identify, investigate, and resolve abnormal events. The surveillance also provides a basis for ensuring that applicable DOE requirements are implemented. 2.0 References 2.1 DOE 5480.19, Conduct of Operations Requirements for DOE Facilities 2.2 DOE-STD-1045-93, Guide To Good Practices for Notifications and Investigations of Abnormal Events 2.3 DOE 232.1A, Occurrence Reporting and Processing of Operations Information 3.0 Requirements Implemented

4

Accurate Automated Detection of Autism Related Corpus Callosum Abnormalities  

Science Conference Proceedings (OSTI)

The importance of accurate early diagnostics of autism that severely affects personal behavior and communication skills cannot be overstated. Neuropathological studies have revealed an abnormal anatomy of the Corpus Callosum (CC) in autistic brains. ... Keywords: Autism, Corpus callosum, Modeling, Segmentation

Ayman El-Baz; Ahmed Elnakib; Manuel F. Casanova; Georgy Gimel'Farb; Andrew E. Switala; Desha Jordan; Sabrina Rainey

2011-10-01T23:59:59.000Z

5

Abnormal Negative Sequence Analysis Excel Application Version 1.0  

Science Conference Proceedings (OSTI)

The Abnormal Negative Sequence Analysis Excel Application can be used to estimate the likely impact of any electrical event on the generator rotor so that a quick informed decision can be made about generator rotor inspection. This project is intended to develop an Excel based application that can be used for assessing the need for turbine generators to be inspected after an abnormal negative sequence or motoring from standstill event may have occurred. Microsoft2000, XP, and Vista running either Micros...

2010-11-29T23:59:59.000Z

6

check list for those with one abnormal BeLPT  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

CHECK LIST FOR THOSE WHO HAVE HAD, OR WHO IN THE FUTURE CHECK LIST FOR THOSE WHO HAVE HAD, OR WHO IN THE FUTURE HAVE, ONE ABNORMAL BeLPT _____ Fill out the EE-1 and EE-3 and include a copy of any abnormal BeLPT results that you have; review the EE-7 form. _____ Make a copy of the completed forms (one to keep for yourself). _____ Take the original copy of your forms (or mail them) to your nearest EEOICPA Resource Center. If you have already filed these forms, please do not fill them out again, just skip to the next item, below. _____ After you are accepted into the DOL program, choose a clinical center where you want to have your medical examinations. Circle the center you choose. _____ Call the clinical center where you want your medical examinations to be performed. ["I have an abnormal beryllium blood test and I need to get

7

Excimer laser phototherapy for the dissolution of abnormal growth  

DOE Patents (OSTI)

Removal of abnormal human tissue with reduced thermal damage is achieved by selecting a laser having a wavelength in the order of 290-400 nm, orienting a laser-transmitting glass member toward the abnormal tissue and directing the laser through the glass member at power densities, pulse rates, and times sufficient to cause multiphoton absorption and bond breaking by Coulomb repulsion rather than thermal destruction. The glass member may include a laser beam concentrator provided by a lens or cone at the tissue-treatment end to increase the beam energy per unit area and reduce the treatment area.

Gruen, Dieter M. (Downers Grove, IL); Young, Charles E. (Westmont, IL); Pellin, Michael J. (Naperville, IL)

1987-01-01T23:59:59.000Z

8

Methods and systems for detecting abnormal digital traffic  

DOE Patents (OSTI)

Aspects of the present invention encompass methods and systems for detecting abnormal digital traffic by assigning characterizations of network behaviors according to knowledge nodes and calculating a confidence value based on the characterizations from at least one knowledge node and on weighting factors associated with the knowledge nodes. The knowledge nodes include a characterization model based on prior network information. At least one of the knowledge nodes should not be based on fixed thresholds or signatures. The confidence value includes a quantification of the degree of confidence that the network behaviors constitute abnormal network traffic.

Goranson, Craig A [Kennewick, WA; Burnette, John R [Kennewick, WA

2011-03-22T23:59:59.000Z

9

Triple-phase bone image abnormalities in Lyme arthritis  

Science Conference Proceedings (OSTI)

Arthritis is a frequent manifestation of Lyme disease. Limited triple-phase Tc-99m MDP bone imaging of the wrists and hands with delayed whole-body images was performed in a patient with Lyme arthritis. This demonstrated abnormal joint uptake in the wrists and hands in all three phases, with increased activity seen in other affected joints on delayed whole-body images. These findings are nonspecific and have been previously described in a variety of rheumatologic conditions, but not in Lyme disease. Lyme disease should be considered in the differential diagnosis of articular and periarticular bone scan abnormalities.

Brown, S.J.; Dadparvar, S.; Slizofski, W.J.; Glab, L.B.; Burger, M. (Hahnemann Univ. Hospital, Philadelphia, PA (USA))

1989-10-01T23:59:59.000Z

10

Detector for flow abnormalities in gaseous diffusion plant compressors  

DOE Patents (OSTI)

A detector detects a flow abnormality in a plant compressor which outputs a motor current signal. The detector includes a demodulator/lowpass filter demodulating and filtering the motor current signal producing a demodulated signal, and first, second, third and fourth bandpass filters connected to the demodulator/lowpass filter, and filtering the demodulated signal in accordance with first, second, third and fourth bandpass frequencies generating first, second, third and fourth filtered signals having first, second, third and fourth amplitudes. The detector also includes first, second, third and fourth amplitude detectors connected to the first, second, third and fourth bandpass filters respectively, and detecting the first, second, third and fourth amplitudes, and first and second adders connected to the first and fourth amplitude detectors and the second and third amplitude detectors respectively, and adding the first and fourth amplitudes and the second and third amplitudes respectively generating first and second added signals. Finally, the detector includes a comparator, connected to the first and second adders, and comparing the first and second added signals and detecting the abnormal condition in the plant compressor when the second added signal exceeds the first added signal by a predetermined value.

Smith, Stephen F. (Loudon, TN); Castleberry, Kim N. (Harriman, TN)

1998-01-01T23:59:59.000Z

11

Detector for flow abnormalities in gaseous diffusion plant compressors  

DOE Patents (OSTI)

A detector detects a flow abnormality in a plant compressor which outputs a motor current signal. The detector includes a demodulator/lowpass filter demodulating and filtering the motor current signal producing a demodulated signal, and first, second, third and fourth bandpass filters connected to the demodulator/lowpass filter, and filtering the demodulated signal in accordance with first, second, third and fourth bandpass frequencies generating first, second, third and fourth filtered signals having first, second, third and fourth amplitudes. The detector also includes first, second, third and fourth amplitude detectors connected to the first, second, third and fourth bandpass filters respectively, and detecting the first, second, third and fourth amplitudes, and first and second adders connected to the first and fourth amplitude detectors and the second and third amplitude detectors respectively, and adding the first and fourth amplitudes and the second and third amplitudes respectively generating first and second added signals. Finally, the detector includes a comparator, connected to the first and second adders, and comparing the first and second added signals and detecting the abnormal condition in the plant compressor when the second added signal exceeds the first added signal by a predetermined value. 6 figs.

Smith, S.F.; Castleberry, K.N.

1998-06-16T23:59:59.000Z

12

OPS 9.6 Investigation of Abnormal Events 8/24/98  

Energy.gov (U.S. Department of Energy (DOE))

The objective of this surveillance is to verify that contractor personnel are effectively investigating abnormal events.  The activities included in this surveillance provide a basis for...

13

Automatic Fault Characterization via Abnormality-Enhanced Classification  

Science Conference Proceedings (OSTI)

Enterprise and high-performance computing systems are growing extremely large and complex, employing hundreds to hundreds of thousands of processors and software/hardware stacks built by many people across many organizations. As the growing scale of these machines increases the frequency of faults, system complexity makes these faults difficult to detect and to diagnose. Current system management techniques, which focus primarily on efficient data access and query mechanisms, require system administrators to examine the behavior of various system services manually. Growing system complexity is making this manual process unmanageable: administrators require more effective management tools that can detect faults and help to identify their root causes. System administrators need timely notification when a fault is manifested that includes the type of fault, the time period in which it occurred and the processor on which it originated. Statistical modeling approaches can accurately characterize system behavior. However, the complex effects of system faults make these tools difficult to apply effectively. This paper investigates the application of classification and clustering algorithms to fault detection and characterization. We show experimentally that naively applying these methods achieves poor accuracy. Further, we design novel techniques that combine classification algorithms with information on the abnormality of application behavior to improve detection and characterization accuracy. Our experiments demonstrate that these techniques can detect and characterize faults with 65% accuracy, compared to just 5% accuracy for naive approaches.

Bronevetsky, G; Laguna, I; de Supinski, B R

2010-12-20T23:59:59.000Z

14

Analysis of Abnormal Wave Records by the Hilbert–Huang Transform Method  

Science Conference Proceedings (OSTI)

The Hilbert–Huang transform method is used in this work to analyze wave records from the North Sea, which include abnormal waves. The analysis of the characteristics of abnormal waves is based on the local decomposition of wave data by using the ...

Albena D. Veltcheva; C. Guedes Soares

2007-09-01T23:59:59.000Z

15

Heart rate variability in preterm neonates with and without abnormal cardiorespiratory events.  

E-Print Network (OSTI)

Heart rate variability in preterm neonates with and without abnormal cardiorespiratory events The heart rate variability (HRV) of preterm neonates undergoing a polysomnography is ana- lyzed in relation experience abnormal cardiorespiratory events, based only on the heart rate recordings during periods without

16

Report to Congress on abnormal occurrences, April--June 1993. Volume 16, No. 2  

SciTech Connect

Section 208 of the Energy Reorganization Act of 1974 identifies an abnormal occurrence as an unscheduled incident or event that the Nuclear Regulatory Commission determines to be significant from the standpoint of public health and safety and requires a quarterly report of such events to be made to Congress. This report covers the period April through June 1993, and discusses four abnormal occurrences at NRC-licensed facilities, three involving medical brachytherapy misadministrations and one involving a research reactor that operated without a safety system. One pool irradiation facility contamination event, two medical misadministrations (one ``sodium iodide`` and one brachytherapy), and one industrial radiographer overexposure event that were reported by NRC Agreement States are also discussed. The report also contains information updating one previously reported abnormal occurrence and information on three other events of interest.

Not Available

1993-09-01T23:59:59.000Z

17

Environmental impact assessment of abnormal events: a follow-up study  

DOE Green Energy (OSTI)

Impact analyses included in environmental assessments for a selected nuclear power plant, petroleum storage facility, crude oil pipeline, and geopressure well that have experienced operational, abnormal events are compared with the data quantifying the environmental impacts of the events. Comparisons of predicted vs actual impacts suggests that prediction of the types of events and associated impacts could be improved; in some instances, impacts have been underestimated. Analysis of abnormal events is especially important in environmental assessment documents addressing a technology that is novel or unique to a particular area. Incorporation of abnormal event impact analysis into project environmental monitoring and emergency response plans can help improve these plans and can help reduce the magnitude of environmental impacts resulting from said events.

Hunsaker, D.B. Jr.; Lee, D.W.

1985-01-01T23:59:59.000Z

18

Method and system for determining precursors of health abnormalities from processing medical records  

DOE Patents (OSTI)

Medical reports are converted to document vectors in computing apparatus and sampled by applying a maximum variation sampling function including a fitness function to the document vectors to reduce a number of medical records being processed and to increase the diversity of the medical records being processed. Linguistic phrases are extracted from the medical records and converted to s-grams. A Haar wavelet function is applied to the s-grams over the preselected time interval; and the coefficient results of the Haar wavelet function are examined for patterns representing the likelihood of health abnormalities. This confirms certain s-grams as precursors of the health abnormality and a parameter can be calculated in relation to the occurrence of such a health abnormality.

Patton, Robert M; Potok, Thomas E; Beckerman, Barbara G

2013-06-25T23:59:59.000Z

19

V-204: A specially crafted query can cause BIND to terminate abnormally |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

V-204: A specially crafted query can cause BIND to terminate V-204: A specially crafted query can cause BIND to terminate abnormally V-204: A specially crafted query can cause BIND to terminate abnormally July 27, 2013 - 4:35am Addthis PROBLEM: A specially crafted query that includes malformed rdata can cause named to terminate with an assertion failure while rejecting the malformed query. PLATFORM: BIND 9.7 ABSTRACT: A specially crafted query sent to a BIND nameserver can cause it to crash (terminate abnormally). REFERENCE LINKS: ISC Knowledge Base CVE-2013-4854 IMPACT ASSESSMENT: High DISCUSSION: BIND is an implementation of the Domain Name System (DNS) protocols. Authoritative and recursive servers are equally vulnerable. Intentional exploitation of this condition can cause a denial of service in all nameservers running affected versions of BIND 9. Access Control Lists do

20

Discovering Potential Precursors of Mammography Abnormalities based on Textual Features, Frequencies, and Sequences  

Science Conference Proceedings (OSTI)

Diagnosingbreastcancerfrommammographyreportsisheav- ily dependant on the time sequences of the patient visits. In the work described, we take a longitudinal view of the text of a patient s mam- mogram reports to explore the existence of certain phrase patterns that indicate future abnormalities may exist for the patient. Our approach uses various text analysis techniques combined with Haar wavelets for the discovery and analysis of such precursor phrase patterns. We believe the results show significant promise for the early detection of breast can- cer and other breast abnormalities.

Patton, Robert M [ORNL; Potok, Thomas E [ORNL

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Combining multiple classifiers to quantitatively rank the impact of abnormalities in flight data  

Science Conference Proceedings (OSTI)

This paper presents a novel two phase method that combines one class support vector machine classifiers using combination rules to quantitatively assess the degree of abnormality at various heights during individual aircraft descents and also over the ... Keywords: Aircraft landing guidance, Artificial intelligence, Fault diagnosis, Support vector machines

E. Smart; D. Brown; J. Denman

2012-08-01T23:59:59.000Z

22

Development and experimental validation of computational methods to simulate abnormal thermal and structural environments  

Science Conference Proceedings (OSTI)

Over the past 40 years, Sandia National Laboratories (SNL) has been actively engaged in research to improve the ability to accurately predict the response of engineered systems to abnormal thermal and structural environments. These engineered systems contain very hazardous materials. Assessing the degree of safety/risk afforded the public and environment by these engineered systems, therefore, is of upmost importance. The ability to accurately predict the response of these systems to accidents (to abnormal environments) is required to assess the degree of safety. Before the effect of the abnormal environment on these systems can be determined, it is necessary to ascertain the nature of the environment. Ascertaining the nature of the environment, in turn, requires the ability to physically characterize and numerically simulate the abnormal environment. Historically, SNL has demonstrated the level of safety provided by these engineered systems by either of two approaches: (1) a purely regulatory approach, or (2) by a Probabilistic Risk Assessment (PRA). This paper will address the latter of the two approaches.

Moya, J.L.; Skocypec, R.D.; Thomas, R.K.

1993-10-01T23:59:59.000Z

23

eDoctor: Automatically Diagnosing Abnormal Battery Drain Issues on Smartphones  

E-Print Network (OSTI)

under typical usage, but at some point the battery unexpectedly started to drain faster than usual usage of the device or a particular app. An energy profiler can give the battery usage of each app phase share similar resource usage patterns. When an app starts to consume energy in an abnormal way

Fainman, Yeshaiahu

24

A Re nery Immobot for Abnormal Situation Management Kurt D. Krebsbach and David J. Musliner  

E-Print Network (OSTI)

be extremely costly,resulting in poor product qual- ity, schedule delays, equipment damage, reduced occu represents an extreme case within the spec- trum of major industrial process disruptions, collec- tively, estimating (abnormal) states, and diagnosing, isolating, and recovering from mal- functions. At the Honeywell

Krebsbach, Kurt D.

25

Automated Heart Wall Motion Abnormality Detection From Ultrasound Images using Bayesian Networks  

E-Print Network (OSTI)

Automated Heart Wall Motion Abnormality Detection From Ultrasound Images using Bayesian Networks± . maleeha.qazi@siemens.com , glenn.fung@siemens.com Abstract Coronary Heart Disease can be diagnosed by mea- suring and scoring regional motion of the heart wall in ultrasound images of the left ventricle (LV

Rosales, Rómer E.

26

Abnormal Gene Expression of Four Genes in Cells from Family Members of  

NLE Websites -- All DOE Office Websites (Extended Search)

Abnormal Gene Expression of Four Genes in Cells from Family Members of Abnormal Gene Expression of Four Genes in Cells from Family Members of Hereditary-type Retinoblastoma Patients relative to Normal Individuals Chin-Yu Wang, 1 Yuanlin Peng, 1 Zhonghui Yang, 2 Chuan-Yuan Li, 2 Hatsumi Nagasawa, 1 Markus M. Fitzek, 3 John B. Little, 4 Joel S. Bedford, 1 and Eric Y. Chuang 5 1 Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado; 2 Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina; 3 Department of Radiation Oncology, Tufts-New England Medical Center; 4 Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts; and 5 Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan

27

Fuzzy-algebra uncertainty analysis for abnormal-environment safety assessment  

Science Conference Proceedings (OSTI)

Many safety (risk) analyses depend on uncertain inputs and on mathematical models chosen from various alternatives, but give fixed results (implying no uncertainty). Conventional uncertainty analyses help, but are also based on assumptions and models, the accuracy of which may be difficult to assure. Some of the models and assumptions that on cursory examination seem reasonable can be misleading. As a result, quantitative assessments, even those accompanied by uncertainty measures, can give unwarranted impressions of accuracy. Since analysis results can be a major contributor to a safety-measure decision process, risk management depends on relating uncertainty to only the information available. The uncertainties due to abnormal environments are even more challenging than those in normal-environment safety assessments, and therefore require an even more cautious approach. A fuzzy algebra analysis is proposed in this report that has the potential to appropriately reflect the information available and portray uncertainties well, especially for abnormal environments.

Cooper, J.A.

1994-01-01T23:59:59.000Z

28

Quantification of abnormal intracranial pressure waves and isotope cisternography for diagnosis of occult communicating hydrocephalus  

SciTech Connect

Nineteen consecutive patients with suspected occult communicating hydrocephalus were investigated by means of clinical evaluation, neuropsychological testing, isotope cisternography, computed tomography scanning, and continuous intracranial pressure monitoring. Semi-quantitative grading systems were used in the evaluation of the clinical, neuropsychological, and cisternographic assessments. Clinical examination, neuropsychological testing, and computed tomography scanning were repeated 3 months after ventriculoperitoneal shunting. All patients showed abnormal intracranial pressure waves and all improved after shunting. There was close correlation between number, peak, and pulse pressures of B waves and the mean intracranial pressure. However, quantification of B waves by means of number, frequency, and amplitude did not help in predicting the degree of clinical improvement postshunting. The most sensitive predictor of favorable response to shunting was enlargement of the temporal horns on computed tomography scan. Furthermore, the size of temporal horns correlated with mean intracranial pressure. There was no correlation between abnormalities on isotope cisternography and clinical improvement.

Cardoso, E.R.; Piatek, D.; Del Bigio, M.R.; Stambrook, M.; Sutherland, J.B.

1989-01-01T23:59:59.000Z

29

Report to Congress on abnormal occurrences, January--March 1995. Volume 18, No. 1  

SciTech Connect

Section 208 of the Energy Reorganization Act of 1974 identifies an abnormal occurrence (AO) as an unscheduled incident or event that the Nuclear Regulatory Commission determines to be significant from the standpoint of public health or safety and requires a quarterly report of such occurrences to be made to Congress. This report provides a description of those incidents and events that have been determined to be AOs during the period of January 1 through March 31, 1995. This report addresses one AO at an NRC-licensed facility which involved a medical brachytherapy misadministration. The report also contains updates of one AO previously reported by an NRC licensee and three AOs previously reported by the Agreement States. No ``Other Events of Interest`` items are being reported.

NONE

1995-07-01T23:59:59.000Z

30

The grain size distribution and the detection of abnormal grain growth of austenite in an eutectoid steel containing niobium  

SciTech Connect

The abnormal grain growth of austenite was studied in a commercial steel of composition (wt%): 0.70 C, 1.36 Mn, 0.72 Si, 0.015 P, 0.027 S and 0.03 Nb. Specimens were thermocycled at various conditions and then grain size distribution determined. The grain size distribution shape did not change during normal grain growth but this distribution widened and flattened during the abnormal grain growth. The initial smaller mean size of carbonitrides and/or the highest homogeneity of niobium carbonitride size distribution of the samples submitted to thermal cycles, in comparison with the normalized samples, increased the abnormal grain growth temperature from 1,373 K to 1,473 K.

Bruno, J.C. (Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Dept. de Engenharia Mecanica e de Materiais); Rios, P.R. (Pontificia Univ. Catolica do Rio de Janeiro (Brazil). Dept. de Ciencia dos Materiais e Metalurgia)

1995-02-15T23:59:59.000Z

31

USENIX Association 10th USENIX Symposium on Networked Systems Design and Implementation (NSDI '13) 57 eDoctor: Automatically Diagnosing Abnormal Battery Drain  

E-Print Network (OSTI)

) 57 eDoctor: Automatically Diagnosing Abnormal Battery Drain Issues on Smartphones Xiao Ma , Peng increase in Abnormal Battery Drain (ABD) prob- lems that can be caused by software defects or miscon- figuration. Such issues can drain a fully-charged battery within a couple of hours, and can potentially

Zhou, Yuanyuan

32

DOE-STD-1045-93 CN-1; Guide to Good Practices for Notifications and Investigation of Abnormal Events  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

5-93 5-93 June 1993 CHANGE NOTICE NO. 1 December 1998 DOE STANDARD GUIDE TO GOOD PRACTICES FOR NOTIFICATIONS AND INVESTIGATION OF ABNORMAL EVENTS U.S. Department of Energy AREA MISC Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document has been reproduced from the best available copy. Available to DOE and DOE contractors from ES&H Technical Information Services, U.S. Department of Energy, (800) 473-4375, fax: (301) 903-9823. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 605-6000. Change Notice No. 1 DOE-STD-1045-93 December 1998 Guide to Good Practices for Notifications and Investigation of Abnormal Events

33

Abnormal humidity-dependent electrical properties of amorphous carbon/silicon heterojunctions  

Science Conference Proceedings (OSTI)

Amorphous carbon (a-C) film/n-Si heterojunctions have been fabricated by pulse laser deposition, and their current-voltage characteristics have been investigated. The results show that the atmosphere relative humidity (RH) has a significant effect on the reverse bias I-V characteristics of the heterojunctions. For the low bias voltages, the resistance of the a-C/Si heterojunction decreases with the increase of the RH. However, when the applied voltage is greater than a threshold, the resistance of the a-C/Si heterojunctions increases with the increase of the RH. This humidity-dependent phenomenon is attributed to the charge transfer from the absorbed H{sub 2}O molecular to a-C film.

Gao Xili; Zhang Xiaozhong; Wan Caihua; Zhang Xin; Wu Lihua; Tan Xinyu [Department of Materials Science and Engineering, Laboratory of Advanced Materials, Tsinghua University, Beijing 100084 (China) and National Center for Electron Microscopy (Beijing), Tsinghua University, Beijing 100084 (China)

2010-11-22T23:59:59.000Z

34

Arsenite promotes centrosome abnormalities under a p53 compromised status induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)  

Science Conference Proceedings (OSTI)

Epidemiological evidence indicated that residents, especially cigarette smokers, in arseniasis areas had significantly higher lung cancer risk than those living in non-arseniasis areas. Thus an interaction between arsenite and cigarette smoking in lung carcinogenesis was suspected. In the present study, we investigated the interactions of a tobacco-specific carcinogen 4- (methylnitrosamino)-1-(3-pyridyl)-1-butanone (nicotine-derived nitrosamine ketone, NNK) and arsenite on lung cell transformation. BEAS-2B, an immortalized human lung epithelial cell line, was selected to test the centrosomal abnormalities and colony formation by NNK and arsenite. We found that NNK, alone, could enhance BEAS-2B cell growth at 1-5 muM. Under NNK exposure, arsenite was able to increase centrosomal abnormality as compared with NNK or arsenite treatment alone. NNK treatment could also reduce arsenite-induced G2/M cell cycle arrest and apoptosis, these cellular effects were found to be correlated with p53 dysfunction. Increased anchorage-independent growth (colony formation) of BEAS-2B cells cotreated with NNK and arsenite was also observed in soft agar. Our present investigation demonstrated that NNK could provide a p53 compromised status. Arsenite would act specifically on this p53 compromised status to induce centrosomal abnormality and colony formation. These findings provided strong evidence on the carcinogenic promotional role of arsenite under tobacco-specific carcinogen co-exposure.

Liao, W.-T. [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Yu, H.-S. [Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Dermatology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Lin Pinpin, E-mail: pplin@nhri.org.t [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Chang, Louis W., E-mail: lwchang44@yahoo.co [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China)

2010-02-15T23:59:59.000Z

35

Non-Canonical NF-kB Activation and Abnormal B Cell Accumulation in Mice Expressing Ubiquitin Protein Ligase-Inactive c-IAP2  

E-Print Network (OSTI)

Chromosomal translocations between loci encoding MALT1 and c-IAP2 are common in MALT lymphomas. The resulting fusion proteins lack the c-IAP2 RING domain, the region responsible for its ubiquitin protein ligase (E3) activity. Ectopic expression of the fusion protein activates the canonical NF-kB signaling cascade, but how it does so is controversial and how it promotes MALT lymphoma is unknown. Considering recent reports implicating c-IAP1 and c-IAP2 E3 activity in repression of non-canonical NF-kB signaling, we asked if the c-IAP2/MALT fusion protein can initiate non-canonical NF-kB activation. Here we show that in addition to canonical activation, the fusion protein stabilizes NIK and activates noncanonical NF-kB. Canonical but not non-canonical activation depended on MALT1 paracaspase activity, and expression of E3-inactive c-IAP2 activated non-canonical NF-kB. Mice in which endogenous c-IAP2 was replaced with an E3-inactive mutant accumulated abnormal B cells with elevated non-canonical NF-kB and had increased numbers of B cells with a marginal zone phenotype, gut-associated lymphoid hyperplasia, and other features of MALT lymphoma. Thus, the c-IAP2/ MALT1 fusion protein activates NF-kB by two distinct mechanisms, and loss of c-IAP2 E3 activity in vivo is sufficient to induce abnormalities common to MALT lymphoma.

Dietrich B. Conze; Yongge Zhao; Jonathan D. Ashwell

2010-01-01T23:59:59.000Z

36

Development of an assessment methodology for geopressured zones of the upper Gulf Coast based on a study of abnormally pressured gas fields in south Texas  

DOE Green Energy (OSTI)

Detailed study of the producing gas fields in south Texas has identified a total of 47 abnormally pressured fields in a six-county area including Hidalgo, Brooks, Cameron, Willacy, Kenedy, and Live Oak Counties. An assessment methodology for assessing the potential of the deep geopressured zone in south Texas as an energy resource was developed, based on investigation of the reservoir parameters of these fields. This methodology is transferrable to broad areas of the Gulf Coast. The depth of the geopressured zone in the study area ranges from 7000 ft in western Hidalgo to 12,000 ft in central Cameron County. Temperature data from within the fields, corrected to undisturbed reservoir values, yields a 300/sup 0/F isogeothermal surface at depths from 10,500 ft to 17,000 ft over the study area. The question of fluid deliverability was found to be paramount in determining the potential of the geopressure-geothermal resource as a practical source of energy. The critical parameter is the effective reservoir permeability throughout the study region. Individual fields were assessed for their potential to produce large quantities of geothermal fluid based on reservoir study and detailed geological investigation. Five locations within the study region have been selected as potential candidates for further evaluation and possible eventual testing. Based on investigation of permeability and temperature, the upper limit of fluid temperature likely to be produced in the lower south Texas study region is 300/sup 0/F. In Live Oak County, the possibility of producing fluid at higher temperatures is somewhat improved, with a reasonable possibility of producing fluid at 350/sup 0/ to 375/sup 0/F.

Swanson, R K; Oetking, P; Osoba, J S; Hagens, R C

1976-08-01T23:59:59.000Z

37

Hydrogeochemical genesis of groundwaters with abnormal fluoride ...  

Science Conference Proceedings (OSTI)

fluoride concentrations from Zhongxiang City, Hubei Province, central China. Qinghai ..... gypsum source calcium can be calculated by subtracting the amount of ...

38

Current developments in oil shale research at the Laramie Energy Research Center. [Review of studies in 4 areas: concurrent gasification and retorting; high pressure retorting; abnormal heating rate of interior of large blocks of oil shale; and in-situ combustion  

DOE Green Energy (OSTI)

Current oil shale research being conducted at the Laramie Energy Research Center is many faceted, and some of the recent developments in these areas are presented. Concurrent gasification and retorting of oil shale where the effects of operating pressure and amounts of oxygen and water injection on quality and quantity of gas and oil produced is being studied. This work has resulted in off gas with heating values varying from 50 to 1,300 Btu/ft/sup 3/ and oil recovery of up to 80 vol percent of Fischer assay. The effects of retorting atmosphere, pressure, and external heating rate are being studied in a high pressure batch retort. Results from this work indicate that a nitrogen atmosphere decreases oil yield slightly while a hydrogen atmosphere increases the oil yield significantly. Large blocks of oil shale are being retorted in a 150-ton aboveground retort to study the abnormal heating rate of the interior of the blocks. This could be caused by an oxidation exotherm similar to that found in limited DTA studies. Some early results from the Rock Springs site 9 in-situ experiment are also presented. This is the fifth in-situ combustion experiment and is being performed in a 40-foot-thick oil shale bed having an average Fischer assay of 23 gallons per ton.

Jacobson, I.A. Jr.; Burwell, E.L.; Harak, A.E.; Long, A.; Wise, R.L.

1976-01-01T23:59:59.000Z

39

139- Recrystallized Grain Size Prediction Based on Abnormal ...  

Science Conference Proceedings (OSTI)

125- Influence of Gas Flow Rate Ratio on the Structural Properties of a-SiC:H Prepared by ... 145- The Synergy of XRD and XRF in a Shale and Slate Analysis.

40

Abnormal heart rate turbulence predicts the initiation of ventricular arrhythmias  

E-Print Network (OSTI)

atrial pacing with onset heart rate = 99 beats/min. (C)Thonet G, Vesin J-M, et al. Heart rate dynamics at the on-M, Barthel P, et al. Heart-rate turbulence after ventricular

Iwasa, Atsushi; Hwa, Michael; Hassankhani, Alborz; Liu, Taylor; Narayan, Sanjiv M

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

A Comparison of Techniques for Detecting Abnormal Change in Blogs  

Science Conference Proceedings (OSTI)

Distributed collections are made of metadata entries that contain references to artifacts not controlled by the collection curators. These collections often have limited forms of change; for digital distributed collections, primarily creation and deletion of additional resources. However, there exists a class of digital collection that undergoes additional kinds of change. These collections consist of resources that are distributed across the Internet and brought together via hyperlinking. Resources in these collections can be expected to change as time goes on. Part of the difficulty in maintaining these collections is determining if a changed page is still a valid member of the collection. Others have tried to address this by defining a maximum allowed threshold of change, however, these methods treat change as a potential problem and treat web content as static despite its intrinsic dynamicism. Instead we acknowledge change on the web as a normal part of a web document and determine the difference between what a maintainer expects a page to do and what it actually does. In this work we evaluate options for extractors and analyzers from a suite of techniques against a human-generated ground-truth set of blog changes. The results of this work show a statistically significant improvement over traditional threshold techniques for our collection.

Furuta, Dr. Richard Keith [Texas A& M University; ShipmanIII, Dr. Frank Major [Texas A& M University; Bogen, Paul Logasa [ORNL

2012-01-01T23:59:59.000Z

42

Abnormally Malicious Autonomous Systems and their Internet Connectivity  

SciTech Connect

While many attacks are distributed across botnets, investigators and network operators have recently targeted malicious networks through high profile autonomous system (AS) de-peerings and network shut-downs. In this paper, we explore whether some ASes indeed are safe havens for malicious activity. We look for ISPs and ASes that exhibit disproportionately high malicious behavior using ten popular blacklists, plus local spam data, and extensive DNS resolutions based on the contents of the blacklists. We find that some ASes have over 80% of their routable IP address space blacklisted. Yet others account for large fractions of blacklisted IP addresses. Several ASes regularly peer with ASes associated with significant malicious activity. We also find that malicious ASes as a whole differ from benign ones in other properties not obviously related to their malicious activities, such as more frequent connectivity changes with their BGP peers. Overall, we conclude that examining malicious activity at AS granularity can unearth networks with lax security or those that harbor cybercrime.

Shue, Craig A [ORNL; Kalafut, Prof. Andrew [Grand Valley State University (GVSU), Michigan; Gupta, Prof. Minaxi [Indiana University

2011-01-01T23:59:59.000Z

43

Abnormal Grain Growth of ODS Superalloys Enhanced by Boron ...  

Science Conference Proceedings (OSTI)

schematically illustrated in Figure l(a) were built in a vacuum bell jar. Heating was done by feeding current through a sample from the grips, while a strain was.

44

Elimination of abnormal combustion in a hydrogen-fueled engine  

DOE Green Energy (OSTI)

This report covers the design, construction, and testing of a dedicated hydrogen-fueled engine. Both part-load and full-load data were taken under laboratory conditions. The engine design included a billet aluminum single combustion chamber cylinder-head with one intake valve, two sodium coiled exhaust valves, and two spark plugs. The cylinder-head design also included drilled cooling passages. The fuel-delivery system employed two modified Siemens electrically actuated fuel injectors, The exhaust system included two separate headers, one for each exhaust port. The piston/ring combination was designed specifically for hydrogen operation.

Swain, M.R.; Swain, M.N. [Analytical Technologies, Inc., Miami, FL (United States)

1995-11-01T23:59:59.000Z

45

Method of detecting genetic deletions identified with chromosomal abnormalities  

DOE Patents (OSTI)

Methods and compositions for staining based upon nucleic acid sequence that employ nucleic acid probes are provided. Said methods produce staining patterns that can be tailored for specific cytogenetic analyzes. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acids probes are typically of a complexity greater tha 50 kb, the complexity depending upon the cytogenetic application. Methods and reagents are provided for the detection of genetic rearrangements. Probes and test kits are provided for use in detecting genetic rearrangements, particlularly for use in tumor cytogenetics, in the detection of disease related loci, specifically cancer, such as chronic myelogenous leukemia (CML) and for biological dosimetry. Methods and reagents are described for cytogenetic research, for the differentiation of cytogenetically similar ut genetically different diseases, and for many prognostic and diagnostic applications.

Gray, Joe W; Pinkel, Daniel; Tkachuk, Douglas

2013-11-26T23:59:59.000Z

46

Method of detecting genetic translocations identified with chromosomal abnormalities  

DOE Patents (OSTI)

Methods and compositions for staining based upon nucleic acid sequence that employ nucleic acid probes are provided. Said methods produce staining patterns that can be tailored for specific cytogenetic analyses. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acid probes are typically of a complexity greater than 50 kb, the complexity depending upon the cytogenetic application. Methods and reagents are provided for the detection of genetic rearrangements. Probes and test kits are provided for use in detecting genetic rearrangements, particularly for use in tumor cytogenetics, in the detection of disease related loci, specifically cancer, such as chronic myelogenous leukemia (CML) and for biological dosimetry. Methods and reagents are described for cytogenetic research, for the differentiation of cytogenetically similar but genetically different diseases, and for many prognostic and diagnostic applications.

Gray, Joe W. (Livermore, CA); Pinkel, Daniel (Walnut Creek, CA); Tkachuk, Douglas (Livermore, CA)

2001-01-01T23:59:59.000Z

47

CHARACTERISTICS OF ABNORMALITIES OBSERVED IN ATOM-BOMB SURVIVORS  

SciTech Connect

Physical and psychosomatic examinations were performed on 356 A-bomb survivors during the 4-yr period complained of fatigue and vertigo, 118 of whom had had no corresponding explanation. There was no significant change in the blood and bone marrow other than a tendency to a higher incidence of either anemia, leukopenia, thrombocytopenia, or their combination, particularly in those who had been exposed at a small distance from the hypocenter. In psychosomatic aspects, almost all the survivors had some complaints such as anxiety, a feeling that their lives were hopeless, and fear of A-bomb effects on their descendants. Bodily complaints seemed to stem from a neurotic basis. Since information on sequelae of A-bomb disease has come mainly from mass communication sources (67%) and also partially from physicians (21%), it should be emphasized that both mass communication sources and physicians must be very cautious in describing the morbid sequelae. (P.C.H.)

Misao, T.

1961-01-01T23:59:59.000Z

48

Abnormal Phases in High W Content Nickel Base Superalloys and ...  

Science Conference Proceedings (OSTI)

2Beijing Institute of Aeronautical Materials, Beijing 100095, China. 3School of Materials ... In China, it was paid attention to develop a series of cast nickel.

49

Abnormal Number Additive Theory of Numbers Algebraic Equation ...  

E-Print Network (OSTI)

... Asymptotically Equivalent Average Order Bachet's Weights Problem Bauer's ... Region Order of a mod m Order of Approximation Order of Magnitude Oxford ...

50

PQ Encyclopedia: Understanding Voltage Unbalance  

Science Conference Proceedings (OSTI)

This PQ Encyclopedia examines voltage unbalance, methods to calculate line voltages and the degree of voltage unbalance, and mitigation techniques.

2009-12-11T23:59:59.000Z

51

HIGH VOLTAGE GENERATOR  

DOE Patents (OSTI)

This patent relates to high voltage supply circuits adapted for providing operating voltages for GeigerMueller counter tubes, and is especially directed to an arrangement for maintaining uniform voltage under changing conditions of operation. In the usual power supply arrangement for counter tubes the counter voltage is taken from across the power supply output capacitor. If the count rate exceeds the current delivering capaciiy of the capacitor, the capacitor voltage will drop, decreasing the counter voltage. The present invention provides a multivibrator which has its output voltage controlled by a signal proportional to the counting rate. As the counting rate increases beyond the current delivering capacity of the capacitor, the rectified voltage output from the multivibrator is increased to maintain uniform counter voltage.

Zito, G.V.

1959-04-21T23:59:59.000Z

52

Mitigation of different type voltage sags in low voltage distribution systems using dynamic voltage restorer  

Science Conference Proceedings (OSTI)

The main problems of the voltage sag in low voltage distribution systems due to sensitive loads. Voltage sags can caused malfunction in the distribution system. In order to protect voltage sags in the network a device which called Dynamic Voltage Restorer ... Keywords: custom device, dynamic voltage restorer (DVR), low voltage, power injected, voltage sag

Rosli Omar

2010-03-01T23:59:59.000Z

53

Automatic voltage imbalance detector  

DOE Patents (OSTI)

A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Bobbett, Ronald E. (Los Alamos, NM); McCormick, J. Byron (Los Alamos, NM); Kerwin, William J. (Tucson, AZ)

1984-01-01T23:59:59.000Z

54

Constant voltage ultracapacitor  

Science Conference Proceedings (OSTI)

Ultracapacitors have attracted lots of attention recently due to their growing use in hybrid vehicles and in energy storage applications for the smart grid. A very undesirable feature of ultracapacitors is the fact that the voltage drops as the capacitor is discharged. DC-DC converters are employed at present to convert the voltage of the ultracapacitor to constant voltage; however

Ezzat G. Bakhoum

2012-01-01T23:59:59.000Z

55

Optical voltage reference  

DOE Patents (OSTI)

An optical voltage reference for providing an alternative to a battery source is described. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function. 2 figures.

Rankin, R.; Kotter, D.

1994-04-26T23:59:59.000Z

56

Optical voltage reference  

DOE Patents (OSTI)

An optical voltage reference for providing an alternative to a battery source. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function.

Rankin, R.; Kotter, D.

1992-12-31T23:59:59.000Z

57

Automated Voltage Standard Ready  

Science Conference Proceedings (OSTI)

... “We wanted a standard that was ... as envisioned, then within our lifetimes there will no longer be a need for voltage transfer standards that have to be ...

2013-04-08T23:59:59.000Z

58

Voltage balanced multilevel voltage source converter system  

SciTech Connect

A voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means.

Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

1997-01-01T23:59:59.000Z

59

Voltage balanced multilevel voltage source converter system  

SciTech Connect

Disclosed is a voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means. 15 figs.

Peng, F.Z.; Lai, J.S.

1997-07-01T23:59:59.000Z

60

Voltage Quality Improvement Using DVR  

Science Conference Proceedings (OSTI)

The problem of voltage sags and Swells and its severe impact on sensitive loads is well known. To solve this problem, custom power devices are used. One of those devices is the Dynamic Voltage Restorer (DVR), which is one of the most efficient and effective ... Keywords: Dynamic Voltage Restorer (DVR), Voltage sags, Voltage swells, Custom power, Power Quality

M. Arun Bhaskar; S. S. Dash; C. Subramani; M. Jagadeesh Kumar; P. R. Giresh; M. Varun Kumar

2010-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Substation voltage upgrading  

SciTech Connect

Substation voltage uprating, i.e., conversion of a substation from a lower rated voltage to a higher rated voltage without a complete substation rebuild, can lead to excellent economic benefits. Utilization of the old substation layout and/or the existing equipment, to some extent, is the practical objective of such an uprating. The objective of this project was to assess the opportunities for substation uprating in the industry, to establish feasibility for such uprating and to study methods for accomplishing it. The final aim of the project was to provide guidance to utilities interested in uprating. 56 refs., 41 figs., 18 tabs.

Panek, J.; Elahi, H.; Sublich, M. (General Electric Co., Schenectady, NY (USA). Systems Development and Engineering Dept.)

1989-08-01T23:59:59.000Z

62

Current-Voltage and Capacitance-Voltage characteristics of Pd ...  

Science Conference Proceedings (OSTI)

Presentation Title, Current-Voltage and Capacitance-Voltage characteristics of Pd ... Nonlocal Modeling in High Rate Deformation and Ductile Fracture of ...

63

? Adjustable Output Voltage  

E-Print Network (OSTI)

The LM25010 features all the functions needed to implement a low cost, efficient, buck regulator capable of supplying in excess of 1A load current. This high voltage regulator integrates an N-Channel Buck Switch, and is available in thermally enhanced LLP-10 and TSSOP-14EP packages. The constant on-time regulation scheme requires no loop compensation resulting in fast load transient response and simplified circuit implementation. The operating frequency remains constant with line and load variations due to the inverse relationship between the input voltage and the on-time. The valley current limit detection is set at 1.25A. Additional features include: VCC under-voltage lock-out, thermal shutdown, gate drive under-voltage lock-out, and maximum duty cycle limiter.

Lmq Is Aec-q Grade

2008-01-01T23:59:59.000Z

64

FINAL PROJECT REPORT LOAD MODELING TRANSMISSION RESEARCH  

E-Print Network (OSTI)

power requirements as a  function of its voltage and reactive power requirements as a function of its voltage andrequirements  require disconnection during abnormal voltages

Lesieutre, Bernard

2013-01-01T23:59:59.000Z

65

High voltage DC power supply  

DOE Patents (OSTI)

A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively. 7 figs.

Droege, T.F.

1989-12-19T23:59:59.000Z

66

Low-voltage gyrotrons  

SciTech Connect

For a long time, the gyrotrons were primarily developed for electron cyclotron heating and current drive of plasmas in controlled fusion reactors where a multi-megawatt, quasi-continuous millimeter-wave power is required. In addition to this important application, there are other applications (and their number increases with time) which do not require a very high power level, but such issues as the ability to operate at low voltages and have compact devices are very important. For example, gyrotrons are of interest for a dynamic nuclear polarization, which improves the sensitivity of the nuclear magnetic resonance spectroscopy. In this paper, some issues important for operation of gyrotrons driven by low-voltage electron beams are analyzed. An emphasis is made on the efficiency of low-voltage gyrotron operation at the fundamental and higher cyclotron harmonics. These efficiencies calculated with the account for ohmic losses were, first, determined in the framework of the generalized gyrotron theory based on the cold-cavity approximation. Then, more accurate, self-consistent calculations for the fundamental and second harmonic low-voltage sub-THz gyrotron designs were carried out. Results of these calculations are presented and discussed. It is shown that operation of the fundamental and second harmonic gyrotrons with noticeable efficiencies is possible even at voltages as low as 5-10 kV. Even the third harmonic gyrotrons can operate at voltages about 15 kV, albeit with rather low efficiency (1%-2% in the submillimeter wavelength region).

Glyavin, M. Yu.; Zavolskiy, N. A.; Sedov, A. S. [Institute of Applied Physics RAS, N. Novgorod 603600 (Russian Federation); Nusinovich, G. S. [IREAP, University of Maryland, College Park, Maryland 20742-3511 (United States)

2013-03-15T23:59:59.000Z

67

Comparative High Voltage Impulse Measurement  

Science Conference Proceedings (OSTI)

... substrate and surrounded by insulating oil; the low ... the amplitudes of the voltage peaks that are ... The uncertainties in the peak output voltages for the ...

2013-04-19T23:59:59.000Z

68

Device for monitoring cell voltage  

SciTech Connect

A device for monitoring a rechargeable battery having a number of electrically connected cells includes at least one current interruption switch for interrupting current flowing through at least one associated cell and a plurality of monitoring units for detecting cell voltage. Each monitoring unit is associated with a single cell and includes a reference voltage unit for producing a defined reference threshold voltage and a voltage comparison unit for comparing the reference threshold voltage with a partial cell voltage of the associated cell. The reference voltage unit is electrically supplied from the cell voltage of the associated cell. The voltage comparison unit is coupled to the at least one current interruption switch for interrupting the current of at least the current flowing through the associated cell, with a defined minimum difference between the reference threshold voltage and the partial cell voltage.

Doepke, Matthias (Garbsen, DE); Eisermann, Henning (Edermissen, DE)

2012-08-21T23:59:59.000Z

69

Electron launching voltage monitor  

DOE Patents (OSTI)

An electron launching voltage monitor measures MITL voltage using a relationship between anode electric field and electron current launched from a cathode-mounted perturbation. An electron launching probe extends through and is spaced from the edge of an opening in a first MITL conductor, one end of the launching probe being in the gap between the MITL conductor, the other end being adjacent a first side of the first conductor away from the second conductor. A housing surrounds the launching probe and electrically connects the first side of the first conductor to the other end of the launching probe. A detector detects the current passing through the housing to the launching probe, the detected current being representative of the voltage between the conductors.

Mendel, Clifford W. (Albuquerque, NM); Savage, Mark E. (Albuquerque, NM)

1992-01-01T23:59:59.000Z

70

Voltage controlled current source  

DOE Patents (OSTI)

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

Casne, Gregory M. (Pittsburgh, PA)

1992-01-01T23:59:59.000Z

71

High frequency breakdown voltage  

SciTech Connect

This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O{degrees}C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f{sub c}, the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f{sub ce}, is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions` concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance.

Chu, Thanh Duy

1992-03-01T23:59:59.000Z

72

Exploiting Generalized Additive Models for Diagnosing Abnormal Energy Use in Buildings  

Science Conference Proceedings (OSTI)

Buildings consume 40% of the energy in industrialized countries. Thus detecting and diagnosing anomalies in the building's energy use is an important problem. The existing approaches either retrieve limited information about the anomaly causes, or are ... Keywords: Fault Detection & Diagnosis, GAM, Prediction

Joern Ploennigs, Bei Chen, Anika Schumann, Niall Brady

2013-11-01T23:59:59.000Z

73

A new p/z technique for the analysis of abnormally pressured gas reservoirs  

E-Print Network (OSTI)

Drip tubing as a means of applying domestic wastewater to soil is increasing in use, especially in clayey soils that are unsuitable for traditional disposal systems. Experiments were undertaken to evaluate operational constraints of drip tubing in regards to the reduction of Escherichia coli in wastewater that reaches the soil surface and the number of instances of wastewater surfacing in these clayey soils. Water colored with a dye and inoculated with E. coli was applied to soil through drip emitters at four dosing rates at two sites. Populations of E. coli in water that reached the soil surface were reduced by less than 20%, regardless of the dosing rate. Approximately 50% of emitters produced water on the soil surface at Site 1 and emitters at Site 2 produced few surfacings. Upon excavation, preferential flow was determined to be the mechanism for wastewater reaching the soil surface. Two depths of burial, 15 and 30 cm, were examined to determine depth effects on the frequency of wastewater reaching the soil surface using newly installed drip tubing. Deeper burial inhibited wastewater from reaching the soil surface, but did not eliminate preferential flow. E. coli populations were not reduced in surfacing wastewater when the depth of burial was increased. These same soils were found to remove greater than 99% of the cells when contaminated water was applied in laboratory column studies. However, this soil was free of preferential flow paths. When water was applied to a uniformly disturbed soil, the distribution of water was not uniformly dispersed spherically around the emitter. Instead, water flowed conically toward the microcosm surface when soil water (P[w]) was highest and dispersed into the bottom of the microcosm in drier samples. Some management practices showed potential to disperse domestic wastewater applied through drip emitters in a manner that will limit the instances of poorly treated wastewater reaching the soil surface.

Gan, Ronald Gunawan

2001-01-01T23:59:59.000Z

74

Nuclear Maintenance Applications Center: The Physical Basis of Abnormal Seal Leakoff Mitigation  

Science Conference Proceedings (OSTI)

This technical update provides insights into the physical basis for the effectiveness of actions taken to address Westinghouse #1 seal leakoff anomalies (that is, when #1 seal leakoff exceeds manufacturer's maximum value or is less than manufacturer's minimum value).

2012-08-16T23:59:59.000Z

75

Investigation of Abnormal Grain Growth in a Friction Stir Welded and ...  

Science Conference Proceedings (OSTI)

... currently developing an advanced crew module for future space exploration missions. .... Grain Refinement of Mg-4Al-1Si Alloy by Intensive Melt Conditioning .

76

Detecting and mitigating abnormal events in large scale networks: budget constrained placement on smart grids  

Science Conference Proceedings (OSTI)

Several scenarios exist in the modern interconnected world which call for an efficient network interdiction algorithm. Applications are varied, including various monitoring and load shedding applications on large smart energy grids, computer network security, preventing the spread of Internet worms and malware, policing international smuggling networks, and controlling the spread of diseases. In this paper we consider some natural network optimization questions related to the budget constrained interdiction problem over general graphs, specifically focusing on the sensor/switch placement problem for large-scale energy grids. Many of these questions turn out to be computationally hard to tackle. We present a particular form of the interdiction question which is practically relevant and which we show as computationally tractable. A polynomial-time algorithm will be presented for solving this problem.

Santhi, Nandakishore [Los Alamos National Laboratory; Pan, Feng [Los Alamos National Laboratory

2010-10-19T23:59:59.000Z

77

Cognitive dysfunction and prefrontal synaptic abnormalities in a mouse model of fragile X syndrome  

E-Print Network (OSTI)

Among the hallmark phenotypes reported in individuals with fragile X syndrome (FXS) are deficits in attentional function, inhibitory control, and cognitive flexibility, a set of cognitive skills thought to be associated ...

Krueger, Dilja D.

78

Structure-fluctuation-induced abnormal thermoelectric properties in semiconductor copper selenide  

Science Conference Proceedings (OSTI)

Thermoelectric effects and related technologies have attracted a great interest due to the world-wide energy harvesting. Thermoelectricity has usually been considered in the context of stable material phases. Here we report that the fluctuation of structures during the second-order phase transition in Cu2Se semiconductor breaks the conventional trends of thermoelectric transports in normal phases, leading to a critically phase-transition-enhanced thermoelectric figure of merit zT above unity at 400K, a three times larger value than for the normal phases. Dynamic structural transformations introduce intensive fluctuations and extreme complexity, which enhance the carrier entropy and thus the thermopower, and strongly scatter carriers and phonons as well to make their transports behave critically.

Liu, Huili [Chinese Academy of Sciences; Shi, Xun [Chinese Academy of Sciences; Kirkham, Melanie J [ORNL; Wang, Hsin [ORNL; Li, Qiang [Brookhaven National Laboratory (BNL); Uher, Ctirad [University of Michigan; Zhang, Wenqing [Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS); Chen, Lidong [Chinese Academy of Sciences

2013-01-01T23:59:59.000Z

79

Abnormal Auditory Cortical Activation in Dyslexia 100 msec after Speech Onset  

Science Conference Proceedings (OSTI)

Reading difficulties are associated with problems in processing and manipulating speech sounds. Dyslexic individuals seem to have, for instance, difficulties in perceiving the length and identity of consonants. Using magnetoencephalography (MEG), we ...

Päivi Helenius; Riitta Salmelin; Ulla Richardson; Seija Leinonen; Heikki Lyytinen

2002-05-01T23:59:59.000Z

80

AAPG Bulletin, v. 87, no. 1 (January 2003), pp. 99119 99 Evolution of abnormally low  

E-Print Network (OSTI)

50­80% of hy- drostatic pressure. Exploration for oil and gas indicates that the hydrocarbon of the depression, whereas oil pools occur at the marginal uplift; some gas reservoirs are located at a very shallow migration and accumulation and gas and oil distribution. The development of un- derpressure is, therefore

Jiao, Jiu Jimmy

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

High voltage pulse conditioning  

DOE Patents (OSTI)

Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

Stringfield, R.M.; Wheat, R.M. Jr.

1989-02-21T23:59:59.000Z

82

High voltage pulse conditioning  

DOE Patents (OSTI)

Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

Springfield, Ray M. (Sante Fe, NM); Wheat, Jr., Robert M. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

83

HIGH VOLTAGE GENERATOR  

DOE Patents (OSTI)

A generator is presented for producing relatively large currents at high voltages. In general, the invention comprises a plurality of capacitors connected in series by a plurality of switches alternately disposed with the capacitors. The circuit is mounted for movement with respect to contact members and switch closure means so that a load device and power supply are connected across successive numbers of capacitors, while the other capacitors are successively charged with the same power supply.

Schwemin, A.J.

1959-03-17T23:59:59.000Z

84

HIGH VOLTAGE GENERATOR  

DOE Patents (OSTI)

A generator for producing relatively large currents at high voltages is described. In general, the invention comprises a plurality of capacitors connected in series by a plurality of switches alternately disposed with the capacitors. The above-noted circuit is mounted for movement with respect to contact members and switch closure means so that a load device and power supply are connected across successive numbers of capacitors, while the other capacitors are successively charged with the same power supply.

Schwemin, A.J.

1959-03-17T23:59:59.000Z

85

HIGH VOLTAGE ION SOURCE  

DOE Patents (OSTI)

A device is described for providing a source of molecular ions having a large output current and with an accelerated energy of the order of 600 kv. Ions are produced in an ion source which is provided with a water-cooled source grid of metal to effect maximum recombination of atomic ions to molecular ions. A very high accelerating voltage is applied to withdraw and accelerate the molecular ions from the source, and means are provided for dumping the excess electrons at the lowest possible potentials. An accelerating grid is placed adjacent to the source grid and a slotted, grounded accelerating electrode is placed adjacent to the accelerating grid. A potential of about 35 kv is maintained between the source grid and accelerating grid, and a potential of about 600 kv is maintained between the accelerating grid and accelerating electrode. In order to keep at a minimum the large number of oscillating electrons which are created when such high voltages are employed in the vicinity of a strong magnetic field, a plurality of high voltage cascaded shields are employed with a conventional electron dumping system being employed between each shield so as to dump the electrons at the lowest possible potential rather than at 600 kv.

Luce, J.S.

1960-04-19T23:59:59.000Z

86

High voltage variable diameter insulator  

DOE Patents (OSTI)

A high voltage feedthrough assembly (10) having a tubular insulator (15) extending between the ground plane ring (16) and the high voltage ring (30). The insulator (15) is made of Pyrex and decreases in diameter from the ground plane ring (16) to the high voltage ring (30), producing equipotential lines almost perpendicular to the wall (27) of the insulator (15) to optimize the voltage-holding capability of the feedthrough assembly (10).

Vanecek, David L. (Martinez, CA); Pike, Chester D. (Pinole, CA)

1984-01-01T23:59:59.000Z

87

Automatic voltage-imbalance detector  

DOE Patents (OSTI)

A device is described for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Bobbett, R.E.; McCormick, J.B.; Kerwin, W.J.

1981-05-20T23:59:59.000Z

88

Planning of distribution networks for medium voltage and low voltage.  

E-Print Network (OSTI)

??Determination of the placement and rating of transformers and feeders are the main objective of the basic distribution network planning. The bus voltage and the… (more)

Ziari, Iman

2011-01-01T23:59:59.000Z

89

High voltage feedthrough bushing  

DOE Patents (OSTI)

A feedthrough bushing for a high voltage diode provides for using compression sealing for all sealing surfaces. A diode assembly includes a central conductor extending through the bushing and a grading ring assembly circumferentially surrounding and coaxial with the central conductor. A flexible conductive plate extends between and compressively seals against the central conductor and the grading ring assembly, wherein the flexibility of the plate allows inner and outer portions of the plate to axially translate for compression sealing against the central conductor and the grading ring assembly, respectively. The inner portion of the plate is bolted to the central conductor for affecting sealing. A compression beam is also bolted to the central conductor and engages the outer portion of the plate to urge the outer portion toward the grading ring assembly to obtain compression sealing therebetween.

Brucker, J.P.

1991-12-31T23:59:59.000Z

90

Substation voltage upgrading  

SciTech Connect

This report addresses specific issues to support sound yet not unduly conservative uprating practices for substations. The main parts of the report cover the insulation withstand and overvoltage protection aspects, environmental measurements, reliability criteria, and industry experience. First the insulation design concerns are addressed. Substation stress by a backflashover of the line insulation due to lightning in the vicinity of the substation is recognized as a critical stress. A representative part of a 550 kV BIL substation was erected at the EPRI High Voltage Transmission Research Center, where also a special test circuit was assembled to produce a fast front, slow tail (0.2/200 {mu}s) wave. The substation as well as some special configurations were tested for line-to-ground and line-to-line withstand. Computer studies were performed to complement the test results. A number of important conclusions was reached. The most prominent result in that the high frequency oscillations, as caused by reflections within the substation, do not effect the Critical Flashover Voltage (CFO). The present practice, based on the highest peak is therefore very conservative. The slow tail of the wave appears to dictate the CFO. An arrester model for computer studies to represent very fast as well as slow phenomena was derived. It is based on full scale arrester test data, made available in this project. The computer program to calculate arrester model parameters is also a part of the report. The electric environmental measurements are reported for the tested substation at the HVTRC and for the uprated substation of Public Service Company of Colorado, both before and after the uprating. The performance is satisfactory when corona free hardware is used. Insulation design criteria are analyzed based on substation reliability, the system viewpoint and consequences of the failure. Utility experience with uprated substations is reviewed.

Panek, J.; Elahi, H.; Lux, A.; Imece, A.F. (General Electric Co., Schenectady, NY (United States). Power Systems Engineering Dept.); LaPanse, R.A.; Stewart, J.R. (Public Service Co. of Colorado, Denver, CO (United States))

1992-04-01T23:59:59.000Z

91

Voltage Vehicles | Open Energy Information  

Open Energy Info (EERE)

Sector Vehicles Product Voltage Vehicles is a nascent, full-service alternative fuel vehicle distributor specializing in the full spectrum of electric vehicles (EV) and...

92

Humidity, Temperature, and Voltage (Presentation)  

SciTech Connect

An update is given on the work of the PV Quality Assurance Task Force; Group 3: studying the effects of humidity, temperature, and voltage bias.

Wohlgemuth, J.

2012-03-01T23:59:59.000Z

93

Strain-optic voltage monitor  

DOE Patents (OSTI)

A voltage monitor which uses the shift in absorption edge of crystalline material to measure strain resulting from electric field-induced deformation of piezoelectric or electrostrictive material, providing a simple and accurate means for measuring voltage applied either by direct contact with the crystalline material or by subjecting the material to an electric field.

Weiss, J.D.

1995-12-31T23:59:59.000Z

94

Two terminal line voltage thermostat  

Science Conference Proceedings (OSTI)

A two terminal line voltage thermostat includes a switch which effectively connects line voltage to a heater load. The entire process is controlled by an integrated circuit microcontroller which is powered by a rectified voltage from a transformer secondary connected to a primary which is in series with the heater load. Backup battery power is provided to maintain limited functions of the microcontroller in the event of overall power loss. The microcontroller is programmed to meet the temperature sensing and control requirements specific to a two terminal electric baseboard heating installation. 7 figs.

Stalsberg, K.J.; Ingalls, J.E.; Hoglund, S.R.

1995-10-10T23:59:59.000Z

95

Chapter 4 - Understanding Voltage Sags  

Science Conference Proceedings (OSTI)

This chapter of the EPRI Solutions PQ Encyclopedia provides information for understanding the voltage sag, which is the single most potent cause of end user power quality (PQ) problems.

2005-12-31T23:59:59.000Z

96

Definition: Automated Voltage Regulators | Open Energy Information  

Open Energy Info (EERE)

Regulators Regulators Jump to: navigation, search Dictionary.png Automated Voltage Regulators Voltage regulators are transformers that can increase or decrease the voltage on a distribution circuit to help keep the voltage within a pre-determined band. Unlike capacitor banks, voltage regulators cannot adjust power factor. These devices typically monitor the voltage at the location where they are connected, and compare it to a programmed set point. If the voltage deviates too far from the set point, the voltage regulator can increase or decrease its output voltage by moving the tap on the secondary side up or down. An automated voltage regulator can operate with remote control signals, or in concert with other area voltage control devices, to help regulate distribution voltage in a coordinated fashion.

97

High-voltage-compatible, fully depleted CCDs  

E-Print Network (OSTI)

result of this high-voltage requirement, we have taken a di?voltage is necessary in order to meet the PSF requirementsrequirements for SNAP have resulted in a need to operate at substrate bias voltages

2006-01-01T23:59:59.000Z

98

Performance of Dynamic Voltage Restorer (DVR) against Voltage Sags and Swells Using Space Vector PWM Technique  

Science Conference Proceedings (OSTI)

Due to increasing complexity in the power system, voltage sags are now becoming one of the most significant power quality problems. Voltage sag is a short reduction voltage from nominal voltage, occurs in a short time. Short-lived voltage sags may not ... Keywords: Custom power, power quality, voltage sag, SPWM, SVPWM, DVR, PSCAD/EMTDC.

Palaparthi Ananthababu; Burle Trinadha; K. Ram Charan

2009-12-01T23:59:59.000Z

99

A CMOS threshold voltage reference source for very-low-voltage applications  

Science Conference Proceedings (OSTI)

This paper describes a CMOS voltage reference that makes use of weak inversion CMOS transistors and linear resistors, without the need for bipolar transistors. Its operation is analogous to the bandgap reference voltage, but the reference voltage is ... Keywords: Threshold voltage, Ultra-low-power, Very-low-voltage, Voltage reference

Luis H. C. Ferreira; Tales C. Pimenta; Robson L. Moreno

2008-12-01T23:59:59.000Z

100

Surge voltage suppression in residential power circuits  

Science Conference Proceedings (OSTI)

... Tran- sients in Low Voltage Supply Systems,'' The ... a high-voltage transformer for an oil furnace ... of service entrance SPD of 1960-1970 vintage were ...

2013-05-17T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Automated Voltage Control in LHCb  

E-Print Network (OSTI)

LHCb is one of the 4 LHC experiments. In order to ensure the safety of the detector and to maximize efficiency, LHCb needs to coordinate its own operations, in particular the voltage configuration of the different subdetectors, according to the accelerator status. A control software has been developed for this purpose, based on the Finite State Machine toolkit and the SCADA system used for control throughout LHCb (and the other LHC experiments). This software permits to efficiently drive both the Low Voltage (LV) and High Voltage (HV) systems of the 10 different sub-detectors that constitute LHCb, setting each sub-system to the required voltage (easily configurable at run-time) based on the accelerator state. The control software is also responsible for monitoring the state of the Sub-detector voltages and adding it to the event data in the form of status-bits. Safe and yet flexible operation of the LHCb detector has been obtained and automatic actions, triggered by the state changes of the ...

Granado Cardoso, L; Jacobsson, R

2011-01-01T23:59:59.000Z

102

Fiber-optic voltage sensor  

DOE Patents (OSTI)

A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities.

Wood, C.B.

1990-12-31T23:59:59.000Z

103

A voltage controlled current source  

DOE Patents (OSTI)

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoampers to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

Casne, G.M.

1990-12-21T23:59:59.000Z

104

Fiber-optic voltage sensor  

DOE Patents (OSTI)

A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities.

Wood, C.B.

1990-01-01T23:59:59.000Z

105

Portec Voltage Regulators: for Emergency Diesel Generators  

Science Conference Proceedings (OSTI)

This report contains information to help utilities address emergency diesel generator voltage regulator issues.

2004-12-15T23:59:59.000Z

106

Ancillary service details: Voltage control  

SciTech Connect

Voltage control is accomplished by managing reactive power on an alternating-current power system. Reactive power can be produced and absorbed by both generation and transmission equipment. Reactive-power devices differ substantially in the magnitude and speed of response and in their capital costs. System operators, transmission owners, generators, customers, power marketers, and government regulators need to pay close attention to voltage control as they restructure the U.S. electricity industry. Voltage control can affect reliability and commerce in three ways: (1) Voltages must be maintained within an acceptable range for both customer and power-system equipment to function properly. (2) The movement of reactive power consumes transmission resources, which limits the ability to move real power and worsens congestion. (3) The movement of reactive power results in real-power losses. When generators are required to supply excessive amounts of reactive power, their real-power production must be curtailed. These opportunity costs are not currently compensated for in most regions. Current tariffs are based on embedded costs. These embedded-cost tariffs average about $0.51/MWh, equivalent to $1.5 billion annually for the United States as a whole. Although this cost is low when compared with the cost of energy, it still aggregates to a significant amount of money. This report takes a basic look at why the power system requires reactive power (an appendix explains the fundamentals of real and reactive power). The report then examines the various types of generation and transmission resources used to supply reactive power and to control voltage. Finally it discusses how these resources are deployed and paid for in several reliability regions around the country. As the U.S. electricity industry is restructured, the generation, transmission, and system-control equipment and functions that maintain voltages within the appropriate ranges are being deintegrated.

Kirby, B.; Hirst, E.

1997-12-01T23:59:59.000Z

107

Probabilistic voltage assessment and VAR compensation  

SciTech Connect

The system voltage profile subject to system elements' forced outage is accessed. Two system voltage reliability indexes are evaluated: the loss of voltage probability, and the expected voltage violation. A similar set of two voltage reliability indexes are also calculated for every load bus in the system. A simple VAR compensation approach is introduced. It enhances the voltage profile assuming a maximum of three overlapping element outages can occur. For purposes of demonstration, the system and load bus voltage reliability indexes are calculated for the AEP 30-bus system. Results of applying the proposed VAR compensation scheme to the 30-bus system are also presented and discussed.

Sharaf, T.A.M.; Berg, G.J.

1988-01-01T23:59:59.000Z

108

High voltage photovoltaic power converter  

DOE Patents (OSTI)

An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

Haigh, Ronald E. (Arvada, CO); Wojtczuk, Steve (Cambridge, MA); Jacobson, Gerard F. (Livermore, CA); Hagans, Karla G. (Livermore, CA)

2001-01-01T23:59:59.000Z

109

TRANSISTOR HIGH VOLTAGE POWER SUPPLY  

DOE Patents (OSTI)

High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.

Driver, G.E.

1958-07-15T23:59:59.000Z

110

Voltage unbalance effects on induction motor performance  

Science Conference Proceedings (OSTI)

The reliability of electric drives and driven motors depends on the quality of the power supply voltage especially in the critical industrial process. In this work, a theoretical study of the effects of voltage unbalances, sags and swells on induction ... Keywords: efficiency, power losses and derating factor, sags, symmetrical components, voltage unbalance

L. Refoufi; H. Bentarzi; F. Z. Dekhandji

2006-09-01T23:59:59.000Z

111

Two-stage sintering inhibits abnormal grain growth during beta to alpha transformation in SiC  

E-Print Network (OSTI)

in polycrystalline SiC: I. J. Am. Ceram. Soc. , 1978, 61,in polycrystalline SiC: II. J. Am. Ceram. Soc. , 1978, 61,? transformation in polycrystalline SiC: III, the thickening

Kueck, Aaron M.

2008-01-01T23:59:59.000Z

112

Perinatal loss and neurological abnormalities among children of the atomic bomb. Nagasaki and Hiroshima revisited, 1949 to 1989  

SciTech Connect

Studies of the survivors of the atomic bombing of Hiroshima and Nagasaki who were exposed to ionizing radiation in utero have demonstrated a significant increase in perinatal loss and the vulnerability of the developing fetal brain to injury. These studies have also helped to define the stages in the development of the human brain that are particularly susceptible to radiation-related damage. Exposure at critical junctures in development increases the risk of mental retardation, small head size, subsequent seizures, and poor performance on conventional tests of intelligence and in school. The most critical period, 8 through 15 weeks after fertilization, corresponds to that time in development when neuronal production increases and migration of immature neurons to their cortical sites of function occurs. The epidemiologic data are, however, too sparse to settle unequivocally the nature of the dose-response function and, in particular, whether there is or is not a threshold to damage. If a threshold does exist, it appears to be in the 0.10- to 0.20-Gy fetal-dose range in this vulnerable gestational period.

Yamazaki, J.N.; Schull, W.J. (Univ. of California, Los Angeles (USA))

1990-08-01T23:59:59.000Z

113

Identification of major responding proteins of abnormal leaf and flower in soybean with an integrative "omics" strategy  

Science Conference Proceedings (OSTI)

Proteomics has been utilized as an effective approach to link phenotype and genome sequence, but effective strategies need to be explored to find target gene(s) from a great number of differentially expressed proteins (DEPs). Here, we present an integrated ...

Lei Chen; Guangnan Xing; Yingjie Xu; Xiaoxiang Liu; Tuanjie Zhao; Junyi Gai

2012-01-01T23:59:59.000Z

114

Integrated Genomic Analysis Identifies Clinically Relevant Subtypes of Glioblastoma Characterized by Abnormalities in PDGFRA, IDH1, EGFR, and NF1  

E-Print Network (OSTI)

super family pathway and NF-kB pathway, such as TRADD, RELB,genes from wound healing and NF-kB signaling. Samples in the

Verhaak, Roel GW

2010-01-01T23:59:59.000Z

115

Intelligent System for Detection of Abnormalities and Theft of Electricity using Genetic Algorithm and Support Vector Machines  

E-Print Network (OSTI)

) analysis in electric utilities using Genetic Algorithm (GA) and Support Vector Machine (SVM). The main identification and voting scheme. Among these, load profiling is one of the most widely used [6], which effectiveness of their operation in reducing NTLs, and detecting fraudulent consumers based on load profiles

Ducatelle, Frederick

116

Influence of voltage drop to electric drive with induction motor and voltage sourced inverter  

Science Conference Proceedings (OSTI)

This paper solves problematic of immunity from the voltage drop of the power supply of the electric drive with induction motor with Voltage-Fed inverter. There are reflected opportune control algorithms for the quickly to change of working regime from ... Keywords: electric drive with induction motor, electric drive with voltage sourced inverter, voltage drop

P. Beneš; J. Fo?t; M. Pittermann

2011-09-01T23:59:59.000Z

117

High voltage RF feedthrough bushing  

DOE Patents (OSTI)

Described is a multi-element, high voltage radio frequency bushing for trmitting RF energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

Grotz, Glenn F. (Huntington Station, NY)

1984-01-01T23:59:59.000Z

118

Low power, scalable multichannel high voltage controller  

DOE Patents (OSTI)

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

2006-03-14T23:59:59.000Z

119

Low power, scalable multichannel high voltage controller  

DOE Patents (OSTI)

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

2008-03-25T23:59:59.000Z

120

Dynamic Voltage Regulation Using Distributed Energy Resources  

Science Conference Proceedings (OSTI)

Many distributed energy resources (DE) are near load centres and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide ancillary services such as voltage regulation, nonactive power compensation, and power factor correction. A synchronous condenser and a microturbine with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Voltage control schemes of the inverter and the synchronous condenser are developed. The experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously, while the dynamic response of the inverter is faster than the synchronous condenser; and that integrated voltage regulation (multiple DE perform voltage regulation) can increase the voltage regulation capability, increase the lifetime of the equipment, and reduce the capital and operation costs.

Xu, Yan [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Kueck, John D [ORNL

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Characterisation of the VELO High Voltage System  

E-Print Network (OSTI)

The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; verification of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence that the high voltage system can be safely used and demonstrate that low noise is produced by the power supplies. LHCb Public Note, LHCb-2008-009Contents 1

Barinjaka Rakotomiaramanana; Chris Parkes; Lars Eklund

2008-01-01T23:59:59.000Z

122

Definition: Operating Voltage | Open Energy Information  

Open Energy Info (EERE)

Voltage Voltage Jump to: navigation, search Dictionary.png Operating Voltage The voltage level by which an electrical system is designated and to which certain operating characteristics of the system are related; also, the effective (root-mean-square) potential difference between any two conductors or between a conductor and the ground. The actual voltage of the circuit may vary somewhat above or below this value.[1] Related Terms system References ↑ Glossary of Terms Used in Reliability Standards An LikeLike UnlikeLike You like this.Sign Up to see what your friends like. inline Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Operating_Voltage&oldid=480559" Categories: Definitions ISGAN Definitions What links here Related changes

123

The effect of DVR location for enhancing voltage sag  

Science Conference Proceedings (OSTI)

Recently, Dynamic Voltage Restorer (DVR) has become a popular power electronic device as a protection for sensitive loads from voltage sag. Voltage sag widely known as one of the major problem in power quality, it is defined as a short reduction of voltage ... Keywords: dynamic voltage restorer, power quality, voltage sag

Rohanim Ibrahim; Ahmed M. A. Haidar; M. Zahim; Herbert Iu

2010-03-01T23:59:59.000Z

124

Lowering Power using the Voltage Identification Bit  

E-Print Network (OSTI)

Voltage identification is a form of adaptive voltage scaling (AVS). The voltage-identification technique described in this application note enables certain devices in the Virtex®-7 family to be operated at a lower voltage of 0.9V while delivering the same specified performance as that of a device operating at the nominal supply voltage of 1.0V. Voltage identification capable devices consume approximately 30 % lower worst case (maximum) static power and correspondingly dissipate less heat. Reduced power consumption is a desirable characteristic and one that Xilinx 7 series FPGAs fulfill in multiple ways. The primary purpose of the voltage-identification technique is to reduce the worst-case power consumption of-1C devices. However, the significance of the voltage-identification technique goes beyond an individual device dissipating less energy, it also can lower the overall system cost. Power supplies and thermal management requirements are normally specified based on the worst-case power demands of all the system’s components. Although the 7 series FPGAs-1C devices are the most cost-effective, the total cost of a product is the sum of all parts, and costs associated with the power supply and thermal management can be significant. The voltage-identification technique specifically reduces worst-case power consumption, which reduces the overall costs associated with specifying a larger power supply, requiring a heat sink, adding forced air cooling, or including similar devices. This application note shows the technical aspects of implementing the voltage-identification technique and introduces a reference design for the VC707 evaluation kit. It also explains how voltage identification fits into the complete power portfolio of Virtex-7 FPGAs and highlights the benefits of using the voltage-identification technique to reduce power consumption and system costs.

Ken Chapman; Jameel Hussein

2012-01-01T23:59:59.000Z

125

Emergency Diesel Generator Voltage Regulator Guidelines  

Science Conference Proceedings (OSTI)

This product kit, containing six separate documents, provides information to help utilities address emergency diesel generator voltage regulator issues and maintenance.

2005-12-20T23:59:59.000Z

126

Characterisation of the VELO High Voltage System  

E-Print Network (OSTI)

The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; vercation of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence th...

Rakotomiaramanana, B; Eklund, L

2008-01-01T23:59:59.000Z

127

Characterisation of the VELO High Voltage System  

E-Print Network (OSTI)

The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; verification of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence...

Rakotomiaramanana, B; Eklund, L

2008-01-01T23:59:59.000Z

128

Enhancing Open Circuit Voltage by Combining Thermoelectric ...  

Science Conference Proceedings (OSTI)

Enhancing Open Circuit Voltage by Combining Thermoelectric Materials and Dye -Sensitized Solar Cell in Series · Estimation of Compressive Strength of High ...

129

Group 3: Humidity, Temperature, and Voltage (Presentation)  

DOE Green Energy (OSTI)

Group 3 is chartered to develop accelerated stress tests that can be used as comparative predictors of module lifetime versus stresses associated with humidity, temperature and voltage.

Wohlgemuth, J.

2013-05-01T23:59:59.000Z

130

Voltage Source Converter Technology for Offshore Grids.  

E-Print Network (OSTI)

??This master thesis has investigated the possible application of voltage source converters (VSC) for the interconnection of offshore installations, i.e. wind farms and petroleum platforms,… (more)

Vormedal, Pål Kristian Myhrer

2010-01-01T23:59:59.000Z

131

Quantum Voltage System Development and Dissemination  

Science Conference Proceedings (OSTI)

... of the unit of electric potential difference, the volt, and precise techniques for measuring voltage are essential to the electrical ... Facilities/Tools Used: ...

2012-11-14T23:59:59.000Z

132

Capturing power at higher voltages from arrays of microbial fuel cells without voltage reversal  

E-Print Network (OSTI)

is too low to be used directly for many practical applications. For example, a single light emitting diode (LED) requires a minimum voltage of 2 V.2 Thus, effective methods of boosting MFC voltages

133

Aalborg Universitet Mitigation of Voltage Sags in CIGRE Low Voltage Distribution Network  

E-Print Network (OSTI)

software version 15.0. Index Terms--Wind Turbine Generator (WTG), Photovoltaic (PV), Voltage Source of voltage sags. I. INTRODUCTION Power quality, reliability and stability are the prime requirement of modern

Bak-Jensen, Birgitte

134

Low voltage ride-through capability improvement of wind power generation using dynamic voltage restorer  

Science Conference Proceedings (OSTI)

Recently, the total amount of generation from wind power plants has been increased all over the world. In this situation, a large amount of disconnection of wind generation may give a serious influence in the power system. Consequently, Low Voltage Ride-Through ... Keywords: dynamic voltage restorer, energy storage, fault ride-through, fixed-speed induction generator, low voltage ride-through, voltage sag, wind power generation

Naohiro Hasegawa; Teruhisa Kumano

2010-02-01T23:59:59.000Z

135

Voltage Stability Studies for Southern Company Services  

Science Conference Proceedings (OSTI)

This report describes a study conducted under an EPRI Tailored Collaboration project to develop and demonstrate procedures for the assessment of voltage security of the Southern Electric System (SES). The contractor used EPRI steady-state analysis tools including VSTAB (Voltage STABility assessment program) to assess stability margins and verified them using EPRI dynamic tools including ETMSP (Extended Transient / Mid-term Stability Program).

1997-12-31T23:59:59.000Z

136

Voltage regulation in linear induction accelerators  

DOE Patents (OSTI)

Improvement in voltage regulation in a Linear Induction Accelerator wherein a varistor, such as a metal oxide varistor when it is placed in parallel with the beam accelerating cavity and the magnetic core. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance.

Parsons, W.M.

1991-03-19T23:59:59.000Z

137

Voltage regulation in linear induction accelerators  

DOE Patents (OSTI)

Improvement in voltage regulation in a linear induction accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core is disclosed. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance. 4 figs.

Parsons, W.M.

1992-12-29T23:59:59.000Z

138

NREL: Measurements and Characterization - Current Versus Voltage  

NLE Websites -- All DOE Office Websites (Extended Search)

Current Versus Voltage Current Versus Voltage The National Renewable Energy Laboratory (NREL) Device Performance group uses current versus voltage (I-V) measurement systems to assess the main performance parameters for photovoltaic (PV) cells and modules. I-V measurement systems determine the output performance of devices, including: open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF), maximum power output of the device (Pmax), voltage at maximum power (Vmax), current at maximum power (Imax), and conversion efficiency of the device (η). Some I-V systems may also be used to perform dark I-V measurements to determine diode properties and series and shunt resistances. We use three I-V systems to measure performance of individual PV cells; and four for modules - two for measurements under simulated conditions; and

139

High Voltage Safety Act | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High Voltage Safety Act High Voltage Safety Act High Voltage Safety Act < Back Eligibility Commercial Construction Developer General Public/Consumer Industrial Installer/Contractor Utility Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Georgia Program Type Safety and Operational Guidelines Siting and Permitting The purpose of the High Voltage Safety Act is to prevent injury to persons and property and interruptions of utility service resulting from accidental or inadvertent contact with high-voltage electric lines by providing that no work shall be done in the vicinity of such lines unless and until the owner or operator thereof has been notified of such work and has taken the appropriate safety measures. The Georgia Public Service Commission requires

140

Flexible method for monitoring fuel cell voltage  

DOE Patents (OSTI)

A method for equalizing the measured voltage of each cluster in a fuel cell stack wherein at least one of the clusters has a different number of cells than the identical number of cells in the remaining clusters by creating a pseudo voltage for the different cell numbered cluster. The average cell voltage of the all of the cells in the fuel cell stack is calculated and multiplied by a constant equal to the difference in the number of cells in the identical cell clusters and the number of cells in the different numbered cell cluster. The resultant product is added to the actual voltage measured across the different numbered cell cluster to create a pseudo voltage which is equivalent in cell number to the number of cells in the other identical numbered cell clusters.

Mowery, Kenneth D. (Noblesville, IN); Ripley, Eugene V. (Russiaville, IN)

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Corona and Motor Voltage Interim Report  

SciTech Connect

It has been suggested that to meet the FreedomCAR objectives for cost, size, weight, efficiency, and reliability higher buss voltages be utilized in HEV and FC automotive applications. The reasoning is that since electric power is equal to the product of voltage and current for a given power a higher voltage and lower current would result in smaller cable and inverter switching components. Consequently, the system can be lighter and smaller. On the other hand, higher voltages are known to require better and thicker electrical insulation that reduce the available slot area for motor windings. One cause of slow insulation breakdown is corona that gradually erodes the insulation and shortens the life expectancy of the motor. This study reports on the results of a study on corona initiating voltages for mush-wound and bobbin-wound stators. A unique testing method is illustrated.

Hsu, J.S.

2005-05-06T23:59:59.000Z

142

Performance of a voltage peak detection-based flickermeter  

Science Conference Proceedings (OSTI)

Voltage fluctuations and rapid voltage changes lead to lamps flickering and disturbance of visual perception may occur consequently. For evaluation of the flicker severity level by means of voltage measurement there was developed an instrument called ... Keywords: Matlab Simulink, flickermeter, interharmonics, performance analysis, voltage fluctuation, voltage peak detection

Jiri Drapela

2009-12-01T23:59:59.000Z

143

Voltage controlled spintronics device for logic applications.  

SciTech Connect

We consider logic device concepts based on our previously proposed spintronics device element whose magnetization orientation is controlled by application of a bias voltage instead of a magnetic field. The basic building block is the voltage-controlled rotation (VCR) element that consists of a four-layer structure--two ferromagnetic layers separated by both nanometer-thick insulator and metallic spacer layers. The interlayer exchange coupling between the two ferromagnetic layers oscillates as a function of applied voltage. We illustrate transistor-like concepts and re-programmable logic gates based on VCR elements.

Bader, S. D.; You, C.-Y.

1999-09-03T23:59:59.000Z

144

Voltage controlled spintronic devices for logic applications  

SciTech Connect

We consider logic device concepts based on our previously proposed spintronics device element whose magnetization orientation is controlled by application of a bias voltage instead of a magnetic field. The basic building block is the voltage-controlled rotation (VCR) element that consists of a four-layer structure--two ferromagnetic layers separated by both nanometer-thick insulator and metallic spacer layers. The interlayer exchange coupling between the two ferromagnetic layers oscillates as a function of applied voltage. We illustrate transistorlike concepts and reprogrammable logic gates based on VCR elements. (c) 2000 American Institute of Physics.

You, Chun-Yeol [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Bader, S. D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2000-05-01T23:59:59.000Z

145

Interphase power controller with voltage injection  

Science Conference Proceedings (OSTI)

This paper introduces a new family of Interphase Power Controllers (IPC) based on the principle of voltage injection commonly used in phase-shifting transformers (PST). The voltage injection IPC exhibits power (active and reactive) control characteristics similar to previously defined IPC's and retains their inherent qualities: passive control, short circuit limitation and voltage decoupling. It also provides more flexibility for the adjustment of the operating points. Two promising topologies are described in more detail. One of them offers the potential of retrofitting existing phase-shifting transformers into full-fledged IPC's.

Beauregard, F.; Brochu, J.; Morin, G.; Pelletier, P. (Centre d'Innovation sur le Transport d'Energie du Quebec, Varennes, Quebec (Canada))

1994-10-01T23:59:59.000Z

146

Low voltage arc formation in railguns  

DOE Patents (OSTI)

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

Hawke, R.S.

1985-08-05T23:59:59.000Z

147

Low voltage arc formation in railguns  

DOE Patents (OSTI)

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

Hawke, Ronald S. (Livermore, CA)

1987-01-01T23:59:59.000Z

148

Low voltage arc formation in railguns  

DOE Patents (OSTI)

A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.

Hawke, R.S.

1987-11-17T23:59:59.000Z

149

High-voltage-compatible, fully depleted CCDs  

SciTech Connect

We describe charge-coupled device (CCD) developmentactivities at the Lawrence Berkeley National Laboratory (LBNL).Back-illuminated CCDs fabricated on 200-300 mu m thick, fully depleted,high-resistivity silicon substrates are produced in partnership with acommercial CCD foundry.The CCDs are fully depleted by the application ofa substrate bias voltage. Spatial resolution considerations requireoperation of thick, fully depleted CCDs at high substrate bias voltages.We have developed CCDs that are compatible with substrate bias voltagesof at least 200V. This improves spatial resolution for a given thickness,and allows for full depletion of thicker CCDs than previously considered.We have demonstrated full depletion of 650-675 mu m thick CCDs, withpotential applications in direct x-ray detection. In this work we discussthe issues related to high-voltage operation of fully depleted CCDs, aswell as experimental results on high-voltage-compatible CCDs.

Holland, Stephen E.; Bebek, Chris J.; Dawson, Kyle S.; Emes, JohnE.; Fabricius, Max H.; Fairfield, Jessaym A.; Groom, Don E.; Karcher, A.; Kolbe, William F.; Palaio, Nick P.; Roe, Natalie A.; Wang, Guobin

2006-05-15T23:59:59.000Z

150

Property:Nominal Voltage | Open Energy Information  

Open Energy Info (EERE)

Nominal Voltage Nominal Voltage Jump to: navigation, search Property Name Nominal Voltage Property Type Number This is a property of type Number. Pages using the property "Nominal Voltage" Showing 22 pages using this property. D Distributed Generation Study/10 West 66th Street Corp + 480 + Distributed Generation Study/615 kW Waukesha Packaged System + 480 + Distributed Generation Study/Aisin Seiki G60 at Hooligans Bar and Grille + 240 + Distributed Generation Study/Arrow Linen + 480 + Distributed Generation Study/Dakota Station (Minnegasco) + 0 + Distributed Generation Study/Elgin Community College + 4,160 + Distributed Generation Study/Emerling Farm + 480 + Distributed Generation Study/Floyd Bennett + 480 + Distributed Generation Study/Harbec Plastics + 480 +

151

Assessment of Voltage Security Methods and Tools  

Science Conference Proceedings (OSTI)

To ensure voltage-secure operation of a power system, VAR control devices must be optimally placed and operated. This project assessed tools and methods that claim to help utilities meet these needs and recommended specific enhancements to these tools.

1995-10-26T23:59:59.000Z

152

Superconducting Low Voltage Direct Current (LVDC) Networks  

Science Conference Proceedings (OSTI)

A low voltage dc superconducting distribution network is a challenging future opportunity for power distribution. This report presents a scheme for a superconducting, parallel- connected, multiterminal dc transmission system.

1994-04-27T23:59:59.000Z

153

System for increasing corona inception voltage of insulating oils  

DOE Patents (OSTI)

The Corona Inception Voltage of insulating oils is increased by repetitive cycles of prestressing the oil with a voltage greater than the corona inception voltage, and either simultaneously or serially removing byproducts of corona by evacuation and heating the oil.

Rohwein, Gerald J. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

154

Spark gap with low breakdown voltage jitter  

SciTech Connect

Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed.

Rohwein, Gerald J. (Albuquerque, NM); Roose, Lars D. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

155

Voltage Control Optimization to Improve Transmission Efficiency  

Science Conference Proceedings (OSTI)

An optimal power flow solution is unique from a conventional power flow solution in that an objective function and user-specified constraints are enforced and satisfied to reach a valid solution. This report presents an analytical study on the optimization of power flow in order to minimize reactive power losses via the modification of generator voltage schedules and transmission switched shunt status. The study examines the potential benefits and applicability of near-real-time voltage control ...

2012-11-08T23:59:59.000Z

156

Modular high voltage power supply for chemical analysis  

DOE Patents (OSTI)

A high voltage power supply for use in a system such as a microfluidics system, uses a DC--DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC--DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

2007-01-09T23:59:59.000Z

157

Modular high voltage power supply for chemical analysis  

DOE Patents (OSTI)

A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

2008-07-15T23:59:59.000Z

158

Cell Voltage Noise Reduction Based on Wavelet in Aluminum ...  

Science Conference Proceedings (OSTI)

Presentation Title, Cell Voltage Noise Reduction Based on Wavelet in Aluminum ... cell voltage signals collected in aluminium electrolysis process are with high ...

159

Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum ...  

Science Conference Proceedings (OSTI)

Dubal Cell Voltage Drop Initiatives towards Low Energy High Amperage Cells · Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum Electrolysis ...

160

Appendix C: California ISO Real Time Voltage Security Assessment...  

NLE Websites -- All DOE Office Websites (Extended Search)

C: California ISO Real Time Voltage Security Assessment (VSA) Prototype Functional SpecificationsPrototype Development Title Appendix C: California ISO Real Time Voltage Security...

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Appendix B: California ISO Real Time Voltage Security Assessment...  

NLE Websites -- All DOE Office Websites (Extended Search)

B: California ISO Real Time Voltage Security Assessment (VSA) Summary Report Title Appendix B: California ISO Real Time Voltage Security Assessment (VSA) Summary Report Publication...

162

Appendix A: California ISO Real Time Voltage Security Assessment...  

NLE Websites -- All DOE Office Websites (Extended Search)

A: California ISO Real Time Voltage Security Assessment (VSA) Project: Summary of Survey Results on Methodologies for use in Real-Time Voltage Security Assessment Title Appendix A:...

163

Green Island Power Authority Transmission Voltage Support System...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Green Island Power Authority Transmission Voltage Support System Project Green Island Power Authority Transmission Voltage Support System Project Power point presentation...

164

Cascode buffer for monolithic voltage conversion operating at high input supply voltages  

E-Print Network (OSTI)

A high-to-low switching DC-DC converter that operates at input supply voltages up to two times as high as the maximum voltage permitted in a nanometer CMOS technology is proposed in this paper. The circuit technique is based on a cascode bridge that maintains the steady-state voltage differences among the terminals of all of the transistors within a range imposed by a specific fabrication technology. The proposed circuit technique permits the full integration of active and passive devices of a switching DC-DC converter with a high voltage conversion ratio in a standard low voltage CMOS process. An efficiency of 87.8 % is achieved for 3.6 volts to 0.9 volts conversion assuming

Volkan Kursun; Gerhard Schrom; Vivek K. De; Eby G. Friedman; Siva G. Narendra

2005-01-01T23:59:59.000Z

165

An Electronic Voltage Transformer Based on WLAN Technology  

Science Conference Proceedings (OSTI)

An electronic voltage transformer based on WLAN technology is developed for adapting to the development trends of substations’ synthesis automation. The transformer is composed of voltage-to-current conversion unit, signal processing unit and data ... Keywords: electronic voltage transformer, voltage-to-current conversion, WLAN technology, digital interface, wireless communication

Jianqin Feng; Qingming Wang; Fen Niu; Guangzhao Cui; Anping Zheng

2010-03-01T23:59:59.000Z

166

Motor voltage high harmonics influence to efficient energy usage  

Science Conference Proceedings (OSTI)

Analysis of the effect of non-sinusoidal voltages on the three-phase induction motor is presented in the paper. When the induction motors are supplied by a rectangular shape of the voltage inverter with high levels of harmonic voltage (Uh,i ... Keywords: energy efficiency, harmonics, induction motor, non-sinusoidal voltage, power losses

Miloje M. Kostic; Branka B. Kostic

2011-07-01T23:59:59.000Z

167

Distribution System Voltage Performance Analysis for High-Penetration Photovoltaics  

DOE Green Energy (OSTI)

This report examines the performance of commonly used distribution voltage regulation methods under reverse power flow.

Liu, E.; Bebic, J.

2008-02-01T23:59:59.000Z

168

Optimal Compensation Algorithms for a Dynamic Voltage Restorer  

Science Conference Proceedings (OSTI)

The Dynamic Voltage Restorer (DVR) as an electronics based custom device, is used to protect sensitive loads from the voltage sags in the power distribution system. With the rapid technology advancement in industrial control processes, it is experiencing ... Keywords: Dynamic Voltage Restorer (DVR), power quality, voltage sag, Zero Active Power Compensation (ZAPC), Minimal Active Power Compensation (MAPC)

Deng Pan; Chen Zhongming; Jiang Peng; Abdelkrim Benchaib; Guillaume De Preville

2010-06-01T23:59:59.000Z

169

Analysis of Voltage Rise Effect on Distribution Network with Distributed  

E-Print Network (OSTI)

appearance of hidden loads and affect the voltage profile of low voltage distribution network. To overcomeAnalysis of Voltage Rise Effect on Distribution Network with Distributed Generation M. A. Mahmud. This paper presents a detail analysis of how does voltage rise on distribution network due to the penetration

Pota, Himanshu Roy

170

Developments in line-voltage thermostats  

Science Conference Proceedings (OSTI)

A thermostat that provides reliable, accurate temperature control is the key to a comfortable, efficient space-heating system. The lack of a commercially available line-voltage thermostat that is affordable and performs well has been a significant factor in limiting the comfort and popularity of zoned residential electric heating systems. With EPRI support, two manufacturers have developed innovative, electronics-based line-voltage thermostats that offer a cost-effective control option for creating a comfortable environment with zoned electric heat. These thermostats also may help reduce energy consumption.

Kesselring, J.

1992-09-01T23:59:59.000Z

171

Electronic circuit for measuring series connected electrochemical cell voltages  

DOE Patents (OSTI)

An electronic circuit for measuring voltage signals in an energy storage device is disclosed. The electronic circuit includes a plurality of energy storage cells forming the energy storage device. A voltage divider circuit is connected to at least one of the energy storage cells. A current regulating circuit is provided for regulating the current through the voltage divider circuit. A voltage measurement node is associated with the voltage divider circuit for producing a voltage signal which is proportional to the voltage across the energy storage cell.

Ashtiani, Cyrus N. (West Bloomfield, MI); Stuart, Thomas A. (Toledo, OH)

2000-01-01T23:59:59.000Z

172

Group 3: Humidity, Temperature and Voltage (Presentation)  

SciTech Connect

This is a summary of the work of Group 3 of the International PV QA Task Force. Group 3 is chartered to develop accelerated stress tests that can be used as comparative predictors of module lifetime versus stresses associated with humidity, temperature and voltage.

Wohlgemuth, J.

2013-09-01T23:59:59.000Z

173

High voltage VLF testing of power cables  

SciTech Connect

This publication describes a laboratory test program conducted with the objective to develop a test that would replace the existing dc withstand test. The article describes the methodology used to establish the voltage duration and magnitude of VLF (0.1 Hz) high voltage field tests suitable for crosslinked polyethylene (XLPE) insulated power cable. The results show that the voltage breakdown of laboratory aged XLPE cable at 0.1 Hz is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz cause very little damage to the cable, and that 0.1 Hz testing appears to be a satisfactory alternate to dc testing. Preliminary values are suggested for voltage magnitude and time duration of cable acceptance, maintenance and proof tests at 0.1 Hz for XLPE cable rated up to 35 kV. A program is underway to similarly evaluate samples of service-aged XLPE cable; as well as to demonstrate the use of the preliminary test values at typical utility installations.

Eager, G.S.; Katz, C.; Fryszczyn, B. [Cable Technology Labs., Inc., New Brunswick, NJ (United States); Densley, J. [Ontario Hydro, Toronto, Ontario (Canada); Bernstein, B.S. [EPRI, Washington, DC (United States)

1997-04-01T23:59:59.000Z

174

The Constant Voltage Transformer (CVT) for Mitigating Effects of Voltage Sags on Industrial Equipment  

E-Print Network (OSTI)

Electric quality problems associated with power interactions between distribution and industrial process control systems can be prevented. Surveys of large users that buy power at the transmission and distribution voltages turn up relatively few complaints about the quality of their incoming power, while surveys of small users connected at secondary voltages tum up numerous complaints about the quality of their incoming power. Three major changes in the characteristics of customer loads and power distribution systems have altered the nature of the power quality equation: (I) greater sensitivity of devices and equipment to electric power variations, (2) the interconnection of sensitive loads in extensive networks and automated processes, and (3) an increase in loads that use power electronics in some type of power conversion configuration [1][2]. This paper presents applications of the constant-voltage transformer (CVT) for mitigating the effects of electric service voltage sags on industrial equipment in an oil refinery. Unlike conventional transformers, the CVT or ferro-resonant transformer allows the core to become saturated with magnetic flux, which maintains a relatively constant output voltage during input voltage variations such as undervoltages, overvoltages, and harmonic distortion.

Ferraro, R. J.; Osborne, R.; Stephens, R.

2000-04-01T23:59:59.000Z

175

Electrical system architecture having high voltage bus  

DOE Patents (OSTI)

An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

Hoff, Brian Douglas (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL)

2011-03-22T23:59:59.000Z

176

Sacramento Area Voltage Support Environmental Impact Statement  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

E E R R A N E V A D A R E G I O N Sacramento Area Voltage Support DRAFT ENVIRONMENTAL IMPACT STATEMENT DRAFT ENVIRONMENTAL IMPACT STATEMENT DOE/EIS-0323 NOVEMBER 2002 COVER SHEET Title: Sacramento Area Voltage Support Draft Environmental Impact Statement (EIS) Lead Agency: Western Area Power Administration (Western) Location: Alameda, Contra Costa, Placer, Sacramento, San Joaquin, and Sutter Counties, State of California. EIS Number: DOE/EIS-0323 Contact: Ms. Loreen McMahon, Environmental Project Manager Western Area Power Administration Sierra Nevada Region 114 Parkshore Drive Folsom, CA 95630 (916) 353-4460 (916) 985-1936 fax email: mcmahon@wapa.gov Website: Information is also available on our website: www.wapa.gov Hotline: 1-877-913-4440 (toll-free) Abstract The Western Area Power Administration's Central Valley Project transmission system forms an integral part of

177

LOW VOLTAGE 14 Mev NEUTRON SOURCE  

DOE Patents (OSTI)

An apparatus yielding high-energy neutrons at the rate of 10/sup 8/ or more per second by the D,T or D,D reactions is described. The deuterium gas filling is ionized by electrons emitted from a filament, and the resulting ions are focused into a beam and accelerated against a fixed target. The apparatus is built in accordance with the relationship V/sub s/ = A--B log pd, where V/sub s/ is the sparking voltage, p the gas pressure, and d the gap length between the high voltage electrodes. Typical parameters to obtain the high neutron yields are 55 to 80 kv, 0.5 to 7.0 ma beam current, 5 to 12 microns D/sub 2/, and a gap length of 1 centimeter.

Little, R.N. Jr.; Graves, E.R.

1959-09-29T23:59:59.000Z

178

Low Swing Dual Threshold Voltage Domino Logic  

E-Print Network (OSTI)

A low swing domino logic technique is proposed to decrease power consumption without sacrificing noise immunity. With the proposed low swing domino logic circuit technique, active power consumption is reduced by up to 9.4% while improving the noise immunity by 2.6% as compared to standard domino logic circuits. It is also shown that by applying a low swing contention reduction technique, the power savings can be further increased by 6.7% while the delay can be improved by 8.6%. A simple and efficient dual threshold voltage (dual-V t ) circuit technique that incorporates low swing signals is also proposed. It is shown that the proposed dual-V technique reduces the standby leakage current by approximately 235 times while offering enhanced delay characteristics as compared to a standard low threshold voltage implementation.

Volkan Kursun; Eby G. Friedman

2002-01-01T23:59:59.000Z

179

HIGH VOLTAGE, HIGH CURRENT SPARK GAP SWITCH  

DOE Patents (OSTI)

A high voltage and current spark gap switch comprising two main electrodes insulatingly supported in opposed spaced relationship and a middle electrode supported medially between the main electrodes and symmetrically about the median line of the main electrodes is described. The middle electrode has a perforation aligned with the median line and an irradiation electrode insulatingly supported in the body of the middle electrode normal to the median line and protruding into the perforation. (AEC)

Dike, R.S.; Lier, D.W.; Schofield, A.E.; Tuck, J.L.

1962-04-17T23:59:59.000Z

180

Low-Voltage Cable Aging Management Guidance  

Science Conference Proceedings (OSTI)

This report, intended for use by power plant engineers and craft and administrative personnel who are responsible for cable system aging management, provides guidance on the effective and efficient application of current information and techniques related to aging and condition monitoring (CM) of low-voltage cables. The identification of cables that are prone to early aging and the timely replacement or repair of cables that are degraded will minimize unnecessary power losses, unplanned shutdowns, ...

2013-12-23T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

A compact high voltage pulse generator  

SciTech Connect

A compact, easily transportable, pulse generator has been developed for a variety of applications that require a pulse duration in the range of 1 {mu} sec., voltages from 150 to 300 KV and current levels from 2,000 to 3,000 amps. The generator has a simple cylindrical configuration and modular construction to facilitate assembly and service. The generator may be operated single-pulse or repetitively at pulse repetition rates to 50 Hz in a burst mode.

Rohwein, G.J.; Babcock, S.R.

1994-07-01T23:59:59.000Z

182

Electro-optic voltage sensor head  

DOE Patents (OSTI)

The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers.

Crawford, Thomas M. (Idaho Falls, ID); Davidson, James R. (Idaho Falls, ID); Woods, Gregory K. (Cornelius, OR)

1999-01-01T23:59:59.000Z

183

Electro-optic voltage sensor head  

DOE Patents (OSTI)

The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers. 6 figs.

Crawford, T.M.; Davidson, J.R.; Woods, G.K.

1999-08-17T23:59:59.000Z

184

Physical design with multiple on-chip voltages  

Science Conference Proceedings (OSTI)

Supply voltage is one of the dominant factors that determine the timing performance and power consumption of VLSI chips. For digital systems with a single supply voltage, some logic devices typically operate faster or more frequently than necessary, ...

Chunhong Chen

2002-04-01T23:59:59.000Z

185

NIST Online Museum of Quantum Voltage Standards, 1990s  

Science Conference Proceedings (OSTI)

... (Artifact 7, Citation: SP Benz, "Superconductor-normal-superconductor junctions for programmable voltage standards," Appl. Phys. Lett., vol. 67, pp. ...

2013-02-28T23:59:59.000Z

186

Activated Sintering, Spark Plasma Sintering and High Voltage ...  

Science Conference Proceedings (OSTI)

Mar 4, 2013 ... Novel Synthesis and Consolidation of Powder Materials : Activated Sintering, Spark Plasma Sintering and High Voltage Electric Discharge ...

187

Dubal Cell Voltage Drop Initiatives towards Low Energy High ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2014 TMS Annual Meeting & Exhibition. Symposium , Aluminum Reduction Technology. Presentation Title, DUBAL CELL VOLTAGE ...

188

Temperature Fitting Method Predicting Equidistant Voltage Drop of ...  

Science Conference Proceedings (OSTI)

High Temperature Compression Test to Determine the Anode Paste ... Temperature Fitting Method Predicting Equidistant Voltage Drop of Anode Nod in  ...

189

Development of the Platform-Mounted Dynamic Voltage Restorer (PMDVR)  

Science Conference Proceedings (OSTI)

The uninterrupted supply of electrical power is critical for many commercial utility customers with sensitive loads. A voltage sag of a few cycles could cause loss of many thousands of dollars due to lost production from process stoppage and associated clean-up issues. The Platform Mounted Dynamic Voltage Restorer (PMDVR) is a distribution voltage level device that compensates for changes in supply line voltage to maintain acceptable input power to customers.

1998-12-31T23:59:59.000Z

190

System for increasing corona inception voltage of insulating oils  

DOE Patents (OSTI)

The Corona Inception Voltage of insulating oils is increased by repetitive cycles of prestressing the oil with a voltage greater than the corona inception voltage, and either simultaneously or serially removing byproducts of corona by evacuation and heating the oil. 5 figs.

Rohwein, G.J.

1998-05-19T23:59:59.000Z

191

Research of Dynamic Voltage Restorer Based on Repetitive Control Strategy  

Science Conference Proceedings (OSTI)

This paper introduces a dynamic voltage restorer with independent three-phase structure, which is controlled on repetitive control strategy. Computer simulation of the whole repetitive control system is performed by Matlab/Simulink, and the results show ... Keywords: Dynamic Voltage Restorer, Repetitive Control, Voltage Sag

Tianyu Liu

2012-10-01T23:59:59.000Z

192

Distributed Generation Source Stiffness and Its Impact on Voltage Distortion  

Science Conference Proceedings (OSTI)

Distributed generators with loads that create high harmonics can cause excessive voltage distortion. This report's objective was to evaluate under controlled laboratory conditions voltage distortion resulting from application of nonlinear load for three different types of rotary generators and one inverter-based generator. Test results also were used to verify the analytical model for predicting voltage distortion from nonlinear load application.

2001-11-27T23:59:59.000Z

193

Selective compensation of voltage harmonics in grid-connected microgrids  

E-Print Network (OSTI)

1 Selective compensation of voltage harmonics in grid-connected microgrids Mehdi Savaghebia , Juan is proposed for selective compensation of main voltage harmonics in a grid- connected microgrid. The aim level. Keywords Distributed Generator (DG); microgrid; grid-connected; voltage harmonics compensation. 1

Vasquez, Juan Carlos

194

Secondary Control for Voltage Unbalance Compensation in an Islanded Microgrid  

E-Print Network (OSTI)

Secondary Control for Voltage Unbalance Compensation in an Islanded Microgrid Mehdi Savaghebi1 microgrid. The aim of the proposed control approach is to enhance the voltage quality at the point of common unbalance. Keywords-distributed generation; microgrid; secondary control; voltage unbalance compensation I

Vasquez, Juan Carlos

195

Capacitively coupled RF voltage probe having optimized flux linkage  

DOE Patents (OSTI)

An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

1999-02-02T23:59:59.000Z

196

Low voltage operation of plasma focus  

SciTech Connect

Plasma foci of compact sizes and operating with low energies (from tens of joules to few hundred joules) have found application in recent years and have attracted plasma-physics scientists and engineers for research in this direction. We are presenting a low energy and miniature plasma focus which operates from a capacitor bank of 8.4 {mu}F capacity, charged at 4.2-4.3 kV and delivering approximately 52 kA peak current at approximately 60 nH calculated circuit inductance. The total circuit inductance includes the plasma focus inductance. The reported plasma focus operates at the lowest voltage among all reported plasma foci so far. Moreover the cost of capacitor bank used for plasma focus is nearly 20 U.S. dollars making it very cheap. At low voltage operation of plasma focus, the initial breakdown mechanism becomes important for operation of plasma focus. The quartz glass tube is used as insulator and breakdown initiation is done on its surface. The total energy of the plasma focus is approximately 75 J. The plasma focus system is made compact and the switching of capacitor bank energy is done by manual operating switch. The focus is operated with hydrogen and deuterium filled at 1-2 mbar.

Shukla, Rohit; Sharma, S. K.; Banerjee, P.; Das, R.; Deb, P.; Prabahar, T.; Das, B. K.; Adhikary, B.; Shyam, A. [Energetics and Electromagnetics Division, Facility for Electromagnetic Systems, Bhabha Atomic Research Center, Visakhapatanam, A.P. 530012 (India)

2010-08-15T23:59:59.000Z

197

High Voltage GaN Schottky Rectifiers  

SciTech Connect

Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V{sub RB}) up to 550V and >2000V, respectively, have been fabricated. The on-state resistance, R{sub ON}, was 6m{Omega}{center_dot} cm{sup 2} and 0.8{Omega}cm{sup 2}, respectively, producing figure-of-merit values for (V{sub RB}){sup 2}/R{sub ON} in the range 5-48 MW{center_dot}cm{sup -2}. At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high biases the current was proportional to the area of this contact. These results suggest that at low reverse biases, the leakage is dominated by the surface component, while at higher biases the bulk component dominates. On-state voltages were 3.5V for the 550V diodes and {ge}15 for the 2kV diodes. Reverse recovery times were <0.2{micro}sec for devices switched from a forward current density of {approx}500A{center_dot}cm{sup -2} to a reverse bias of 100V.

CAO,X.A.; CHO,H.; CHU,S.N.G.; CHUO,C.-C.; CHYI,J.-I.; DANG,G.T.; HAN,JUNG; LEE,C.-M.; PEARTON,S.J.; REN,F.; WILSON,R.G.; ZHANG,A.P.

1999-10-25T23:59:59.000Z

198

Abnormal diagnosis of Emergency Department triage explored with data mining technology: An Emergency Department at a Medical Center in Taiwan taken as an example  

Science Conference Proceedings (OSTI)

Triage helps to classify patients at emergency departments to make the most effective use of resources distributed. What is more important is that accuracy in carrying out triage matters greatly in terms of medical quality, patient satisfaction and life ... Keywords: Data mining, Decision tree, Emergency medicine, K-means, Triage

Wen-Tsann Lin; Shen-Tsu Wang; Ta-Cheng Chiang; Yu-xin Shi; Wei-yu Chen; Huei-min Chen

2010-04-01T23:59:59.000Z

199

Neurological and behavioral abnormalities, ventricular dilatation, altered cellular functions, inflammation, and neuronal injury in brains of mice due to common, persistent, parasitic infection  

E-Print Network (OSTI)

Mouse Thymic Virus (MTV) Bacterial pathogens Mycoplasma pulmonis; Salmonella spp.; Citrobacer rodentium; Clostridium piliforme; Cilia Associated Respiratory (CAR) Bacillus Parasitic pathogens Endoparasites; Pinworms (Syphaciasp, Aspiculuris tetraptera... and quantitated using a spectrophotometer (260 lamba). The extinction coefficient aliquots of 40 ?g (260/ 280 was less than 1.6) were utilized for hybridization For hybridization experiments 40 ?g total RNA was mixed with a 17 mer dT oligo (Sigma) and reverse...

Hermes, Gretchen; Ajioka, James W; Kelly, Krystyna A; Mui, Ernest; Roberts, Fiona; Kasza, Kristen; Mayr, Thomas; Kirisits, Michael J; Wollman, Robert; Ferguson, David J P; Roberts, Craig W; Hwang, Jong-Hee; Trendler, Toria; Kennan, Richard P; Suzuki, Yasuhiro; Reardon, Catherine; Hickey, Adam William; Chen, Lieping; McLeod, Rima

2008-10-23T23:59:59.000Z

200

Cortical mechanisms of normal and abnormal processing in the visual system, Part 1: Spatial vision, amblyopia, hyperacuity, modal assumptions: A review  

Science Conference Proceedings (OSTI)

Vernier thresholds rise much more rapidly in the periphery than do grating thresholds. A similar dissociation between acuity and hyperacuity has been shown to be present in strabismic but not in anisometropic amblyopia, thus leading to the suggestion ... Keywords: Peripheral vision, aliasing, amblyopia, anisometropia, hyperacuity, strabismus

F. Fankhauser; S. Kwasniewska

2009-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Action plan for response to abnormal conditions in Hanford high level radioactive liquid waste storage tanks containing flammable gases. Revision 1  

DOE Green Energy (OSTI)

Radioactive liquid waste tends to produce hydrogen as a result of the interaction of gamma radiation and water. In tanks containing organic chelating agents, additional hydrogen gas as well as nitrous oxide and ammonia can be produced by thermal and radiolytic decomposition of these organics. Several high-level radioactive liquid waste storage tanks, located underground at the Hanford Site, contain waste that retains the gases produced in them until large quantities are released rapidly to the tank vapor space. Tanks filled to near capacity have relatively little vapor space; therefore, if the waste suddenly releases a large amount of hydrogen and nitrous oxide, a flammable gas mixture may result. The most notable waste tank with a flammable gas problem is tank 241-SY-101. Waste in this tank has occasionally released enough flammable gas to burn if an ignition source had been present inside of the tank. Several other waste tanks exhibit similar behavior to a lesser magnitude. Administrative controls have been developed to assure that these Flammable Gas Watch List tanks are safely maintained. Responses have also been developed for off-normal conditions which might develop in these tanks. In addition, scientific and engineering studies are underway to further understand and mitigate the behavior of the Flammable Gas Watch List tanks.

Sherwood, D.J.

1994-03-01T23:59:59.000Z

202

Planar LTCC transformers for high voltage flyback converters.  

SciTech Connect

This paper discusses the design and use of low-temperature (850 C to 950 C) co-fired ceramic (LTCC) planar magnetic flyback transformers for applications that require conversion of a low voltage to high voltage (> 100V) with significant volumetric constraints. Measured performance and modeling results for multiple designs showed that the LTCC flyback transformer design and construction imposes serious limitations on the achievable coupling and significantly impacts the transformer performance and output voltage. This paper discusses the impact of various design factors that can provide improved performance by increasing transformer coupling and output voltage. The experiments performed on prototype units demonstrated LTCC transformer designs capable of greater than 2 kV output. Finally, the work investigated the effect of the LTCC microstructure on transformer insulation. Although this paper focuses on generating voltages in the kV range, the experimental characterization and discussion presented in this work applies to designs requiring lower voltage.

Schofield, Daryl (NASCENT Technology Inc. , Watertown, SD); Schare, Joshua M.; Glass, Sarah Jill; Roesler, Alexander William; Ewsuk, Kevin Gregory; Slama, George (NASCENT Technology Inc. , Watertown, SD); Abel, Dave (NASCENT Technology Inc. , Watertown, SD)

2007-06-01T23:59:59.000Z

203

Minimum Energy Compensation Strategy and Characteristic Analysis for Dynamic Voltage Restorer  

Science Conference Proceedings (OSTI)

The minimum energy compensation strategy and its characteristic for Dynamic Voltage Restorer (DVR) considering the equipment’s voltage limitation are discussed. The strategy when the injection voltage is under or especially above the voltage limitation ... Keywords: dynamic voltage restorer, minimum energy compensation, compensation strategy, compensation characteristic, voltage limitation

Yingying Liu; Xu Yonghai; Xiao Xiangning; Guo Chunlin

2009-10-01T23:59:59.000Z

204

Research on the SPLL based single phase voltage sag detection technique  

Science Conference Proceedings (OSTI)

The drop of voltage amplitude and the jump of phase angle are two important parameters of the voltage sag. The design of Dynamic Voltage Restorer (DVR) compensation voltage with voltage sag parameters is discussed and a single-phase sag parameter detection ... Keywords: SPLL, detection, single-phase, voltage sag

Xie Yue; Chen Le; Sun Jian; Gong Xu

2008-04-01T23:59:59.000Z

205

Sequential circuit design for radiation hardened multiple voltage integrated circuits  

DOE Patents (OSTI)

The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

Clark, Lawrence T. (Phoenix, AZ); McIver, III, John K. (Albuquerque, NM)

2009-11-24T23:59:59.000Z

206

Waveform Characteristics of Voltage Sags: Definition and Algorithm Development  

Science Conference Proceedings (OSTI)

Voltage disturbances lasting more than one cycle are normally characterized in terms of voltage magnitude and event duration. These parameters provide an easily understood means of characterizing these types of voltage disturbances. However, magnitude and duration are not the only characteristics that affect loads. Many types of loads, such as contactors, control systems, and ac/dc drives, are also affected by other factors, such as the waveshape, the point in the waveform at which the disturbance begins...

1999-08-05T23:59:59.000Z

207

Triple voltage dc-to-dc converter and method  

DOE Patents (OSTI)

A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

Su, Gui-Jia (Knoxville, TN)

2008-08-05T23:59:59.000Z

208

High Voltage Electric Discharge Consolidation of Tantalum Powders  

Science Conference Proceedings (OSTI)

Abstract Scope, The high voltage electric discharge consolidation (HVEDC) is a promising method of the volumetric-porous body manufacturing, which can be ...

209

The Current-voltage Characteristics of Grain Boundaries in Ionic ...  

Science Conference Proceedings (OSTI)

Presentation Title, The Current-voltage Characteristics of Grain Boundaries in Ionic ... A High-temperature Mössbauer Study of Iron-doped Ruddlesden-popper  ...

210

(SPS) and High Voltage Electric Discharge Consolidation (HVEDC  

Science Conference Proceedings (OSTI)

Presentation Title, Inter-Particle Contact Phenomena in Spark-Plasma Sintering ( SPS) and High Voltage Electric Discharge Consolidation (HVEDC). Author(s) ...

211

Spark-plasma Sintering vs. High Voltage Electric Discharge ...  

Science Conference Proceedings (OSTI)

High voltage electric discharge consolidation (HVEDC) includes high axial pressure and discharge of the electrical energy stored in capacitors, thus enabling a ...

212

Voltage Controlled Creep of a Nanoporous Gold/Electrolyte Hybrid ...  

Science Conference Proceedings (OSTI)

And the creep rate can also be controlled by the voltage (electrochemical ... CNT Reinforced Copper Composite for High Contact Pressure Electrodes by ...

213

(SPS) and High Voltage Electric Discharge Consolidation (HVEDC)  

Science Conference Proceedings (OSTI)

Presentation Title, Local Heat Balance in Spark-plasma Sintering (SPS) and High Voltage Electric Discharge Consolidation (HVEDC). Author(s), Eugene ...

214

Road to AC Voltage Standard Leads to Important Junction  

Science Conference Proceedings (OSTI)

Road to AC Voltage Standard Leads to Important Junction. ... Grumman in the mid-1990s.*** A number of innovations since then have led to the first ...

2013-08-13T23:59:59.000Z

215

Chronic Benzodiazepine Administration Potentiates High Voltage-Activated Calcium Currents  

E-Print Network (OSTI)

.aspetjournals.orgDownloadedfrom #12;other drugs of abuse has been reported to enhance high voltage-activated calcium channels (HVAs

Brand, Paul H.

216

fault diagnosis of a high voltage transmission line using waveform ...  

E-Print Network (OSTI)

Oct 4, 2013 ... FAULT DIAGNOSIS OF A HIGH VOLTAGE TRANSMISSION LINE USING ... Fault types such as single line to ground, line to line, double line to ...

217

Multi-winding Homopolar Electric Machine Offers Variable Voltage ...  

Wind Energy Industrial Technologies Multi-winding Homopolar Electric Machine Offers Variable Voltage at Low Rotational Speed Oak Ridge National Laboratory. Contact ...

218

Energy-Big voltage, little package... | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

News DOE Pulse Media Contacts Media Mentions RSS Feeds News Home | ORNL | News | Story Tips SHARE Energy-Big voltage, little package Oak Ridge National Laboratory's new Stinger...

219

Specifying a Low-Voltage Dynamic Sag Corrector  

Science Conference Proceedings (OSTI)

Voltage sags are the most frequent and costly of power quality problems for industrial customers. A number of non-battery-based technologies have emerged in the market to mitigate the effects of voltage sags on industrial processes. Among these, the low-voltage dynamic sag corrector (DySC) can provide ride-through during sags to 50 percent of nominal voltage for up to 12 cycles with no energy storage; for longer ride-through or deeper sags, energy storage capacitors are available as an option. This repor...

2000-11-07T23:59:59.000Z

220

A Step Towards Energy-Efficient Voltage Control of Magnetic ...  

Science Conference Proceedings (OSTI)

... By combining these two types of materials, it is possible to create low ... by electric fields (applied voltage) instead of less energy-efficient magnetic ...

2013-07-30T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Medium Voltage Cable Aging Management Guide, Revision 1  

Science Conference Proceedings (OSTI)

Medium-voltage cables (5- to 35-kV rated cables) have provided reasonable service in nuclear power plants. However, there is a concern that cables that have experienced long periods of wet service might degrade and fail in service. Because most plants have had few problems with medium-voltage cable, little on-staff experience with medium-voltage cables exists at most sites. This report has been prepared to provide information that will be of practical use when questions concerning medium-voltage cable lo...

2010-11-29T23:59:59.000Z

222

Operating standby redundant controller to improve voltage source inverter reliability .  

E-Print Network (OSTI)

??This thesis presents a control architecture that achieves operating standby redundancy for a voltage source inverter controller. The system was designed to increase reliability by… (more)

Blevins, Stephen T.

2007-01-01T23:59:59.000Z

223

California ISO Real-Time Voltage Security Assessment (VSA) Project...  

NLE Websites -- All DOE Office Websites (Extended Search)

Arnold Schwarzenegger Governor REAL-TIME GRID RELIABILITY MANAGEMENT California ISO Real-Time Voltage Security Assessment (VSA) Project: Summary of Survey Results on Methodologies...

224

Patents and Perspective on Surge Protection for Low-Voltage ...  

Science Conference Proceedings (OSTI)

... In a high-voitage inverter the impedance is a resistor functioning to dampen voltage o\\ershoots and to im- plement a relay or solid state second ...

2013-05-17T23:59:59.000Z

225

Surge Protection in Low-Voltage AC Power Circuits  

Science Conference Proceedings (OSTI)

Surge Protection in Low-Voltage AC Power Circuits: An 8-part Anthology ... converting old and yellowing papers into 21st Century electronic files, and ...

2013-05-20T23:59:59.000Z

226

Voltage Unbalance: Power Quality Issues, Related Standards and Mitigation Techniques: Effect of Unbalanced Voltage on End Use Equipm ent Performance  

Science Conference Proceedings (OSTI)

Unbalanced voltages can result in adverse effects on equipment and the electric distribution system. Under unbalanced conditions the distribution system will incur more losses and heating effects, and be less stable. The effect of voltage unbalance can also be detrimental to equipment such as induction motors, power electronic converters, and adjustable speed drives (ASDs). The purpose of this study is to investigate the causes and effects of voltage unbalance as well as the related standards and mitigat...

2000-06-21T23:59:59.000Z

227

Local Dynamic Reactive Power for Correction of System Voltage Problems  

SciTech Connect

Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results are also provided and discussed. The simulations and testing show that local voltage control from DER can prevent local voltage collapse. The results also show that the control can be provided so quickly, within 0.5 seconds, that is does not interfere with conventional utility methods.

Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL

2008-12-01T23:59:59.000Z

228

Robust Design of Basic Low Voltage CMOS Transconductors  

Science Conference Proceedings (OSTI)

Two new low voltage transconductors are introduced and the statistical design of these transconductors are presented. The circuits operate in the saturation region with fully balanced input signals. Initial circuit simulation results are given. Response surface ... Keywords: design of experiments, low voltage, response surface methodology, roboust design, yield enhancement

Tuna B. Tarim; H. Hakan Kuntman; Mohammed Ismail

1999-09-01T23:59:59.000Z

229

Motor voltage asymmetry influence to the efficient energy usage  

Science Conference Proceedings (OSTI)

Analysis of the effect of unbalanced voltages on the three-phase induction motor is presented in the paper. Since the unbalanced voltage of 2%, 3.5% and 5% increase in losses could reach, in the same order, the amount of 8%, 25% and 50% of nominal power ... Keywords: asymetry, energy efficiency, induction motor, power losses, standard

Miloje Kostic; Aleksandar Nikolic

2010-07-01T23:59:59.000Z

230

Analysis of Voltage Notching Concerns at a Petroleum Pumping Station  

Science Conference Proceedings (OSTI)

This report presents the results of a voltage notching investigation at a petroleum pumping station. The analysis in this paper focuses on a particular example system where the voltage notching caused significant oscillations at the distribution system level, resulting in equipment problems at another customer supplied from the same system.

2003-12-31T23:59:59.000Z

231

Compile-time dynamic voltage scaling settings: opportunities and limits  

Science Conference Proceedings (OSTI)

With power-related concerns becoming dominant aspects of hardware and software design, significant research effort has been devoted towards system power minimization. Among run-time power-management techniques, dynamic voltage scaling (DVS) has emerged ... Keywords: analytical model, compiler, dynamic voltage scaling, low power, mixed-integer linear programming

Fen Xie; Margaret Martonosi; Sharad Malik

2003-06-01T23:59:59.000Z

232

Real-time static voltage scaling on multiprocessors  

Science Conference Proceedings (OSTI)

We propose a real-time static voltage scaling (RT-SVS) technique called T-L plane transforming, which is an extension of LLREF, an optimal real-time scheduling algorithm for multiprocessor systems. We present two RT-SVS algorithms for different types ... Keywords: energy consumption, multiprocessor systems, real-time scheduling, real-time voltage scaling

Kenji Funaoka; Shinpei Kato; Nobuyuki Yamasaki

2007-11-01T23:59:59.000Z

233

Proceedings: EPRI/NERC Forum on Voltage Stability  

Science Conference Proceedings (OSTI)

As power systems are operated at increased stress, utilities are becoming more concerned about voltage collapse and consequent severe disruptions. This meeting, cosponsored by EPRI and NERC, provided a forum for a group of international experts to exchange information on voltage stability, including its physical understanding, operational practices, and application of available tools.

1993-06-01T23:59:59.000Z

234

Wind Farm Grid Voltage Stability Researching Based on Cascade STATCOM  

Science Conference Proceedings (OSTI)

Though most wind turbine use induction generator, when wind induction generator with power generation, it will produce a series of power quality problems such as voltage fluctuations. This paper discusses the mathematical model of the wind induction ... Keywords: Wind induction generator, Cascade STATCOM, Wind farm, Voltage stability

Li Shengqing, Xu Wenxiang, Li Weizhou, Zeng Huanyue

2013-01-01T23:59:59.000Z

235

Definition: Automated Voltage And Var Control | Open Energy Information  

Open Energy Info (EERE)

Voltage And Var Control Voltage And Var Control Jump to: navigation, search Dictionary.png Automated Voltage And Var Control Automated voltage and VAR control requires coordinated operation of reactive power resources such as capacitor banks, voltage regulators, transformer load-tap changers, and distributed generation (DG) with sensors, controls, and communications systems. These devices could operate autonomously in response to local events or in response to signals from a central control system.[1] View on Wikipedia Wikipedia Definition Also Known As Volt-VAR Control (VVC) Related Terms smart grid, Reactive Power References ↑ SmartGrid.gov 'Description of Functions' An i LikeLike UnlikeLike You like this.Sign Up to see what your friends like. nline Glossary Definition Retrieved from

236

E-beam high voltage switching power supply  

DOE Patents (OSTI)

A high-power power supply produces a controllable, constant high voltage put under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

1996-01-01T23:59:59.000Z

237

E-beam high voltage switching power supply  

DOE Patents (OSTI)

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 figs.

Shimer, D.W.; Lange, A.C.

1996-10-15T23:59:59.000Z

238

Living and Working Safely Around High-Voltage Power Lines.  

Science Conference Proceedings (OSTI)

High-voltage transmission lines can be just as safe as the electrical wiring in the homes--or just as dangerous. The crucial factor is ourselves: they must learn to behave safely around them. This booklet is a basic safety guide for those who live and work around power lines. It deals primarily with nuisance shocks due to induced voltages, and with potential electric shock hazards from contact with high-voltage lines. References on possible long-term biological effects of transmission lines are shown. In preparing this booklet, the Bonneville Power Administration has drawn on more than 50 years of experience with high-voltage transmission. BPA operates one of the world`s largest networks of long-distance, high-voltage lines. This system has more than 400 substations and about 15,000 miles of transmission lines, almost 4,400 miles of which are operated at 500,000 volts.

United States. Bonneville Power Administration.

2001-06-01T23:59:59.000Z

239

Reactive Power Management to Address Short-Term Voltage Stability Using Optimal Reactive Power Allocation Method  

Science Conference Proceedings (OSTI)

Voltage stability has attracted attention recently because power systems are increasingly operated under heavy loads and subjected to high levels of dynamic fast acting loads. Voltage instability under these conditions can be manifested as depressed voltage profiles, delayed voltage recovery at load buses following a major disturbance, and even fast voltage collapse. Single-phase, low-inertia induction motors can have adverse effect on voltage stability as they decelerate in the event of voltage ...

2012-11-28T23:59:59.000Z

240

Improving the low voltage ride through of doubly fed induction generator during intermittent voltage source converter faults  

E-Print Network (OSTI)

on the low voltage ride through (LVRT) capability of the doubly fed induction generator (DFIG) is also) controller to mitigate the effects of these faults is proposed. The DFIG compliance with numerous and compared. Simulation results indicate that these types of faults have a severe impact on the DFIG voltage

Pota, Himanshu Roy

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

High voltage dc-dc converter with dynamic voltage regulation and decoupling during load-generated arcs  

DOE Patents (OSTI)

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

1995-01-01T23:59:59.000Z

242

High voltage dc--dc converter with dynamic voltage regulation and decoupling during load-generated arcs  

DOE Patents (OSTI)

A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 Figs.

Shimer, D.W.; Lange, A.C.

1995-05-23T23:59:59.000Z

243

Optically triggered high voltage switch network and method for switching a high voltage  

DOE Patents (OSTI)

An optically triggered solid state switch and method for switching a high voltage electrical current. A plurality of solid state switches (350) are connected in series for controlling electrical current flow between a compensation capacitor (112) and ground in a reactive power compensator (50, 50') that monitors the voltage and current flowing through each of three distribution lines (52a, 52b and 52c), which are supplying three-phase power to one or more inductive loads. An optical transmitter (100) controlled by the reactive power compensation system produces light pulses that are conveyed over optical fibers (102) to a switch driver (110') that includes a plurality of series connected optical triger circuits (288). Each of the optical trigger circuits controls a pair of the solid state switches and includes a plurality of series connected resistors (294, 326, 330, and 334) that equalize or balance the potential across the plurality of trigger circuits. The trigger circuits are connected to one of the distribution lines through a trigger capacitor (340). In each switch driver, the light signals activate a phototransistor (300) so that an electrical current flows from one of the energy reservoir capacitors through a pulse transformer (306) in the trigger circuit, producing gate signals that turn on the pair of serially connected solid state switches (350).

El-Sharkawi, Mohamed A. (Renton, WA); Andexler, George (Everett, WA); Silberkleit, Lee I. (Mountlake Terrace, WA)

1993-01-19T23:59:59.000Z

244

Low-voltage-swing Monolithic DC-DC Conversion  

E-Print Network (OSTI)

Abstract—A low-voltage-swing MOSFET gate drive technique is proposed in this paper for enhancing the efficiency characteristics of high-frequency-switching dc–dc converters. The parasitic power dissipation of a dc–dc converter is reduced by lowering the voltage swing of the power transistor gate drivers. A comprehensive circuit model of the parasitic impedances of a monolithic buck converter is presented. Closed-form expressions for the total power dissipation of a low-swing buck converter are proposed. The effect of reducing the MOSFET gate voltage swings is explored with the proposed circuit model. A range of design parameters is evaluated, permitting the development of a design space for full integration of active and passive devices of a low-swing buck converter on the same die, for a target CMOS technology. The optimum gate voltage swing of a power MOSFET that maximizes efficiency is lower than a standard full voltage swing. An efficiency of 88 % at a switching frequency of 102 MHz is achieved for a voltage conversion from 1.8 to 0.9 V with a low-swing dc–dc converter based on a 0.18- m CMOS technology. The power dissipation of a low-swing dc–dc converter is reduced by 27.9 % as compared to a standard full-swing dc–dc converter. Index Terms—Buck converter, dc–dc converters, enhanced efficiency, high frequency, low power, low swing, monolithic integration, on-chip voltage conversion, parameter optimization, parasitic impedances, power dissipation modeling, power supply, reduced energy dissipation, reduced voltage swing, switching voltage regulator. I.

Volkan Kursun; Siva G. Narendra; Vivek K. De; Eby G. Friedman

2004-01-01T23:59:59.000Z

245

A Survey on the Principle and Control of Dynamic Voltage Restorer  

Science Conference Proceedings (OSTI)

With the development of information and automation techniques, dynamic voltage problems are once again in the spotlight. Dynamic voltage restorer (DVR) is a modern and important custom power device used for mitigating voltage sags in power distribution ... Keywords: voltage sag, dynamic voltage restorer (DVR), control strategy, power quality, optimized compensation, energy storage

Shuhong Kong; Zhongdong Yin; Renzhong Shan; Weidong Shang

2009-10-01T23:59:59.000Z

246

Fault Detection and Isolation in Low-Voltage DC Distribution ...  

A University of Colorado research team led by Jae-Do Park has developed a fault detection and isolation scheme for a low-voltage DC-bus microgrid system, ...

247

NIST Online Museum of Quantum Voltage Standards, 1970s  

Science Conference Proceedings (OSTI)

... Metrologists wondered if they could connect several junctions in series to make a larger voltage, just as a 12-volt car battery is made up of six 2-volt ...

2011-03-30T23:59:59.000Z

248

Fusing strategies for the dual-voltage fault  

E-Print Network (OSTI)

This thesis focuses on the 42V - 14V fault in a dual voltage system and discusses the possibility of effective fusing. A simple model for the system had been created from technical documentation. Based on the model and the ...

Shrivastava, Rupam, 1981-

2005-01-01T23:59:59.000Z

249

Functionalized High Voltage Spinel Composite for High Power ...  

Science Conference Proceedings (OSTI)

Recently, spinel LiNi0.5Mn1.5O4 with high working voltage and long cycle life makes it become the one of most promising cathode for high power delivery.

250

ESS 2012 Peer Review - Low Cost, Manufacturable High Voltage...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Storage for Power Flow Management and Voltage Control on an 11kV UK Distribution Network", 20th International Conference on Electricity Distribution, June 2009. S1 S2 C1 C2...

251

Multilevel cascade voltage source inverter with seperate DC sources  

SciTech Connect

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

1997-01-01T23:59:59.000Z

252

Multilevel cascade voltage source inverter with seperate DC sources  

DOE Patents (OSTI)

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

Peng, Fang Zheng (Knoxville, TN); Lai, Jih-Sheng (Blacksburg, VA)

2002-01-01T23:59:59.000Z

253

Design & Fabrication of a High-Voltage Photovoltaic Cell  

DOE Green Energy (OSTI)

Silicon photovoltaic (PV) cells are alternative energy sources that are important in sustainable power generation. Currently, applications of PV cells are limited by the low output voltage and somewhat low efficiency of such devices. In light of this fact, this project investigates the possibility of fabricating high-voltage PV cells on float-zone silicon wafers having output voltages ranging from 50 V to 2000 V. Three designs with different geometries of diffusion layers were simulated and compared in terms of metal coverage, recombination, built-in potential, and conduction current density. One design was then chosen and optimized to be implemented in the final device design. The results of the simulation serve as a feasibility test for the design concept and provide supportive evidence of the effectiveness of silicon PV cells as high-voltage power supplies.

Felder, Jennifer; /North Carolina State U. /SLAC

2012-09-05T23:59:59.000Z

254

Robust Design of Basic Low Voltage CMOS Transconductors  

Science Conference Proceedings (OSTI)

Two new low voltage transconductors are introduced and the statistical design of these transconductors are presented. The circuits operate in the saturation region with fully balanced input signals. Initial circuit simulation results are given. Response surface ...

Tuna B. Tarim; H. Hakan Kuntman; Mohammed Ismail

1999-09-01T23:59:59.000Z

255

High-voltage air-core pulse transformers  

SciTech Connect

General types of air core pulse transformers designed for high voltage pulse generation and energy transfer applications are discussed with special emphasis on pulse charging systems which operate up to the multi-megavolt range. The design, operation, dielectric materials, and performance are described. It is concluded that high voltage air core pulse transformers are best suited to applications outside the normal ranges of conventional magnetic core transformers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The principal disadvantage of high voltage air core transformers is that they are not generally available from commercial sources. Consequently, the potential user must become thoroughly familiar with all aspects of design, fabrication and system application before he can produce a high performance transformer system. (LCL)

Rohwein, G. J.

1981-01-01T23:59:59.000Z

256

Quartz crystal microbalance based on passive frequency to voltage converter  

SciTech Connect

In dynamics of evaporation or drying of microdrops from a solid surface, a faster and precise quartz crystal microbalance (QCM) is needed. The fast QCM based on frequency to voltage converter is an attractive and powerful tool in the investigation of the dynamic regime of evaporation to translate the frequency shift in terms of a continuous voltage change. The frequency shift monitoring in fast QCM applications is a real challenge for electronic processing interface. Originally developed as a frequency shift processing interface, this novel passive frequency to voltage converter can produce faster, stable, and accurate results in regard to the QCM sensor behavior. In this article, the concept and circuit of passive frequency to voltage converter will be explained followed by static and dynamic characterization. Experimental results of microdrops evaporation will be given.

Burda, Ioan; Tunyagi, Arthur [Department of Physics, Babes-Bolyai University, Cluj-Napoca, 400084 (Romania)

2012-02-15T23:59:59.000Z

257

High power impulse magnetron sputtering: Current-voltage-time ...  

pauses between pulses !typically 20 ms". The nominal volt-age of the pulser was adjustable up to 1000 V. The arc threshold was set to 120 A. If the current exceeded this

258

Planar LTCC transformers for high voltage flyback converters: Part II.  

Science Conference Proceedings (OSTI)

This paper is a continuation of the work presented in SAND2007-2591 'Planar LTCC Transformers for High Voltage Flyback Converters'. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechnoloy, Inc, who collaborated in the design and manufacturing of the planar LTCC flyback converters. The output/volume requirements were targeted to DoD application for hard target/mini fuzing at around 1500 V for reasonable primary peak currents. High voltages could be obtained but with considerable higher current. Work had begun on higher voltage systems and is where this report begins. Limits in material properties and processing capabilities show that the state-of-the-art has limited our practical output voltage from such a small part volume. In other words, the technology is currently limited within the allowable funding and interest.

Schofield, Daryl (NASCENTechnology, Inc., Watertown, SD); Schare, Joshua M., Ph.D.; Slama, George (NASCENTechnology, Inc., Watertown, SD); Abel, David (NASCENTechnology, Inc., Watertown, SD)

2009-02-01T23:59:59.000Z

259

Multilevel cascade voltage source inverter with separate DC sources  

DOE Patents (OSTI)

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations. 15 figs.

Peng, F.Z.; Lai, J.S.

1997-06-24T23:59:59.000Z

260

Time varying voltage combustion control and diagnostics sensor  

DOE Patents (OSTI)

A time-varying voltage is applied to an electrode, or a pair of electrodes, of a sensor installed in a fuel nozzle disposed adjacent the combustion zone of a continuous combustion system, such as of the gas turbine engine type. The time-varying voltage induces a time-varying current in the flame which is measured and used to determine flame capacitance using AC electrical circuit analysis. Flame capacitance is used to accurately determine the position of the flame from the sensor and the fuel/air ratio. The fuel and/or air flow rate (s) is/are then adjusted to provide reduced flame instability problems such as flashback, combustion dynamics and lean blowout, as well as reduced emissions. The time-varying voltage may be an alternating voltage and the time-varying current may be an alternating current.

Chorpening, Benjamin T. (Morgantown, WV); Thornton, Jimmy D. (Morgantown, WV); Huckaby, E. David (Morgantown, WV); Fincham, William (Fairmont, WV)

2011-04-19T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Light Flicker in Compact Fluorescent Lamps Caused by Voltage Fluctuations  

Science Conference Proceedings (OSTI)

This power quality (PQ) case study presents tests performed at the EPRI Power Electronics Applications Center (PEAC) Power Quality Test Facility to characterize the light output of an incandescent lamp and compact fluorescent lamps during voltage fluctuations.

2003-12-31T23:59:59.000Z

262

A Novel Dynamic Voltage Restorer with Outage Handling Capability Using Fuzzy Logic Controler  

Science Conference Proceedings (OSTI)

This paper presents a novel dynamic voltage restorer (DVR) capable of handling deep sags including outage on a low voltage distribution system. The DVR recovers sags up to 10% of nominal voltage; otherwise, it will operate as an uninterruptible power ...

M. Ashari; T. Hiyama; M. Pujiantara; H. Suryoatmojo; M. Hery Purnomo

2007-09-01T23:59:59.000Z

263

Elevated Neutral to Earth and Contact Voltages in Distribution Systems  

Science Conference Proceedings (OSTI)

Perceptible voltage potentials at publicly and privately accessible human and animal contact locations pose concerns for utilities, regulators, and the public. Each year since 2004, EPRI research in this area has considered the most important concerns associated with these perceptible voltages by promoting consistent and repeatable assessment methodologies, sponsoring workshops, and creating a repository of case studies and general information. These and other project efforts are geared toward expediting...

2008-12-18T23:59:59.000Z

264

INTENSITY OF BETATRON RADIATION AS FUNCTION OF INJECTION VOLTAGE  

SciTech Connect

The intensity of betatron radiation emission as a function of injection voltage was studied using a 25-Mev betatron with a 350-kw external electron injector. The injection voltage was measured every 20 to 30 kw from 50 to 250 kw. The results showed that up to 250 kw, emission intensity increases according to theory. It is suggested that an increase in injection intensity up to 1000 kw and over should result in a considerable rise in emission intensity. (R.V.J.)

Moskalev, V.A.; Okulov, B.V.

1962-09-01T23:59:59.000Z

265

Chloromethyl chlorosulfate as a voltage delay inhibitor in lithium cells  

DOE Patents (OSTI)

Chloromethyl chlorosulfate (CMCS) is used as a passive film growth inhibitor in electrochemical cells to minimize voltage delay and low-voltage discharge. Film growth on lithium anodes is significantly diminished when CMCS is added to SOCl{sub 2} and SO{sub 2}Cl{sub 2} electrolytes of lithium batteries. The CMCS also has the effect of extending the shelf-life of Li/SOCl{sub 2} and Li/SO{sub 2}Cl{sub 2} batteries.

Delnick, F.M.

1991-04-05T23:59:59.000Z

266

Cable Aging Management Training Course for Low-Voltage Cables  

Science Conference Proceedings (OSTI)

The "EPRI PSE Cable Aging Training Course for Low-Voltage Cables" provides a basis for understanding of the aging of the insulation and jackets of electrical cables used in low-voltage systems. Practical techniques for determining which cables are prone to premature aging and for evaluating their condition are described. The course contains 11 modules. The first 9 modules describe the body of the cable aging management process. The last two modules, "Cable Failure Assessment" and "Performing a Walkdown o...

2003-11-24T23:59:59.000Z

267

Optical control system for high-voltage terminals  

DOE Patents (OSTI)

An optical control system for the control of devices in the terminal of an electrostatic accelerator includes a laser that is modulated by a series of preselected codes produced by an encoder. A photodiode receiver is placed in the laser beam at the high-voltage terminal of an electrostatic accelerator. A decoder connected to the photodiode decodes the signals to provide control impulses for a plurality of devices at the high voltage of the terminal.

Bicek, John J. (Tinley Park, IL)

1978-01-01T23:59:59.000Z

268

Chloromethyl chlorosulfate as a voltage delay inhibitor in lithium cells  

DOE Patents (OSTI)

Chloromethyl chlorosulfate (CMCS) is used as a passive film growth inhibitor in electrochemical cells to minimize voltage delay and low-voltage discharge. Film growth on lithium anodes is significantly diminished when CMCS is added to SOCl.sub.2 and SO.sub.2 Cl.sub.2 electrolytes of lithium batteries. The CMCS also has the effect of extending the shelf-life of Li/SOCl.sub.2 and Li/SO.sub.2 Cl.sub.2 batteries.

Delnick, Frank M. (Albuquerque, NM)

1993-01-01T23:59:59.000Z

269

Chloromethyl chlorosulfate as a voltage delay inhibitor in lithium cells  

DOE Patents (OSTI)

Chloromethyl chlorosulfate (CMCS) is used as a passive film growth inhibitor in electrochemical cells to minimize voltage delay and low-voltage discharge. Film growth on lithium anodes is significantly diminished when CMCS is added to SOCl[sub 2] and SO[sub 2]Cl[sub 2] electrolytes of lithium batteries. The CMCS also has the effect of extending the shelf-life of Li/SOCl[sub 2] and Li/SO[sub 2]Cl[sub 2] batteries.

Delnick, F.M.

1993-04-13T23:59:59.000Z

270

Measuring Helical FCG Voltage with an Electric Field Antenna  

SciTech Connect

A method of measuring the voltage produced by a helical explosive flux compression generator using a remote electric field antenna is described in detail. The diagnostic has been successfully implemented on several experiments. Measured data from the diagnostic compare favorably with voltages predicted using the code CAGEN, validating our predictive modeling tools. The measured data is important to understanding generator performance, and is measured with a low-risk, minimally intrusive approach.

White, A D; Anderson, R A; Javedani, J B; Reisman, D B; Goerz, D A; Ferriera, A J; Speer, R D

2011-08-01T23:59:59.000Z

271

High voltage series connected tandem junction solar battery  

DOE Patents (OSTI)

A high voltage series connected tandem junction solar battery which comprises a plurality of strips of tandem junction solar cells of hydrogenated amorphous silicon having one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon, arranged in a tandem configuration, can have the same bandgap or differing bandgaps. The tandem junction strip solar cells are series connected to produce a solar battery of any desired voltage.

Hanak, Joseph J. (Lawrenceville, NJ)

1982-01-01T23:59:59.000Z

272

High voltage electrical amplifier having a short rise time  

DOE Patents (OSTI)

A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and the voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage. 8 figs.

Christie, D.J.; Dallum, G.E.

1989-12-07T23:59:59.000Z

273

High voltage electrical amplifier having a short rise time  

DOE Patents (OSTI)

A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage.

Christie, David J. (Pleasanton, CA); Dallum, Gregory E. (Livermore, CA)

1991-01-01T23:59:59.000Z

274

Centralized wind power plant voltage control with optimal power flow algorithm.  

E-Print Network (OSTI)

??This thesis presents a method of controlling the reactive power injected into a medium-voltage collection system by multiple wind turbine generators such that the voltage… (more)

Kline, Jared Andrew

2011-01-01T23:59:59.000Z

275

Voltage stability limits for weak power systems with high wind penetration.  

E-Print Network (OSTI)

??Analysis of power system voltage stability has practical value in increasing wind penetration levels. As wind penetration levels increase in power systems, voltage stability challenges… (more)

Tamimi, Ala

2011-01-01T23:59:59.000Z

276

Improving the low voltage ride through of doubly fed induction generator during intermittent voltage source converter faults  

Science Conference Proceedings (OSTI)

The impact of different voltage source converter (VSC) faults on the low voltage ride through (LVRT) capability of the doubly fed induction generator (DFIG) is also investigated. Faults such as fire-through of the VSC switches and short circuit across the DC-link capacitor are considered in this paper. The impact of internal VSC faults when they occur within the grid side converter (GSC)

2013-01-01T23:59:59.000Z

277

E-beam high voltage switching power supply  

DOE Patents (OSTI)

A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360.degree./n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load.

Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

1997-01-01T23:59:59.000Z

278

E-beam high voltage switching power supply  

DOE Patents (OSTI)

A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360{degree}/n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load. 7 figs.

Shimer, D.W.; Lange, A.C.

1997-03-11T23:59:59.000Z

279

Technical evaluation report on the monitoring of electric power to the reactor-protection system for the Pilgrim Nuclear Power Station  

Science Conference Proceedings (OSTI)

This report documents the technical evaluation of the monitoring of electric power to the reactor protection system (RPS) at the Pilgrim Nuclear Power Station. The evaluation is to determine if the proposed design modification will protect the RPS from abnormal voltage and frequency conditions which could be supplied from the power supplies and will meet certain requirements set forth by the Nuclear Regulatory Commission. The proposed design modifications will protect the RPS from sustained abnormal voltage and frequency conditions from the supplying sources.

Selan, J.C.

1982-04-29T23:59:59.000Z

280

Interaction of Multiple Distributed Energy Resources in Voltage Regulation  

Science Conference Proceedings (OSTI)

Distributed energy resources (DE) with power electronics (PE) interfaces with the right control are capable of providing reactive power related ancillary services; voltage regulation in particular has drawn much attention. In this paper the problem of how to coordinate control multiple DEs to regulate the local voltage in the distribution system is addressed. A control method for voltage regulation using the DE PE controller is presented and based on the proposed control scheme; the voltage regulation of a distribution system with one DE and two DEs are tested, respectively. The factors affecting the gain parameters of the PE controller are investigated. The simulation results show that the parameters of the controller determine its dynamic response for voltage regulation and the factors associated with the network characteristics, such as locations of DEs and the amount of load, affect the impact range of the controller. The research work presented in this paper can be potentially used for the control system design of Smart Grid or Utility of the Future.

Li, Huijuan [University of Tennessee, Knoxville (UTK); Li, Fangxing [ORNL; Xu, Yan [ORNL; Rizy, D Tom [ORNL; Kueck, John D [ORNL

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Experiment Hazard Class 13.0 - High Voltage  

NLE Websites -- All DOE Office Websites (Extended Search)

3.0 - High Voltage 3.0 - High Voltage Applicability This hazard classification applies to all experiments involving the use of High Voltage Equipment. Other hazard classifications and their associated hazard controls may also apply to experiments in this hazard class. The inspection of electric equipment is covered under the APS Policy For User Electric Equipment Inspections. NOTE: Unless required Argonne training has been completed, users are not authorized to perform electrical work. Experiment Category All Hazard Class 13 experiments are categorized as medium risk experiments. Experiment Hazard Control Verification Statements Engineered Controls - Determined by review and results of a DEEI inspection of the equipment. Procedural Controls - Determined by review and results of a DEEI

282

Dynamic Voltage Scaling on a Low-Power Microprocessor  

E-Print Network (OSTI)

Power consumption is the limiting factor for the functionality of future wearable devices. Since interactive applications like wireless information access generate bursts of activities, it is important to match the performance of the wearable device accordingly. This paper describes a system with a microprocessor whose speed can be varied (frequency scaling) as well as its input voltage. Voltage scaling is important for reducing power consumption to very low values when operating at low speeds. Measurements show that the energy per instruction at minimal speed (59 MHz) is 1/5 of the energy required at full speed (251 MHz). The frequency and voltage can be scaled dynamically from user space in only 140 ¡ s. This allows power-aware applications to quickly adjust the performance level of the processor whenever the workload changes. 1

Johan Pouwelse; Koen Langendoen; Henk Sips

2001-01-01T23:59:59.000Z

283

Proceedings: EPRI/NERC forum on voltage stability  

SciTech Connect

Over the past two decades, the interconnected electric systems serving North America have been increasingly subjected to reductions in generation and transmission capacity reserves, increasing complexity of load character, and the need for power transfer over longer distances. As a result, voltage stability limitations are becoming an important factor for utility personnel to consider when designing and operating an electric system. To address this situation, EPRI and NERC cosponsored a forum to exchange information between the various sectors of the utility industry on voltage control technology. The forum covered available tools and practices; utility operating practices, procedures, and experiences; planning and operating studies; and energy management system (EMS) vendor viewpoints. Participants agreed that a continuing coordinated effort involving all industry groups was needed in the voltage stability area. Attendees also identified specific subject areas of importance to help direct future studies. Individual papers are indexed separately.

Maratukulam, D. (ed.) (Kennedy (Thomas), Florissant, MO (United States))

1993-05-01T23:59:59.000Z

284

Minimization of voltage deviation and power losses in power networks using Pareto optimization methods  

Science Conference Proceedings (OSTI)

Voltage regulation is an important task in electrical engineering for controlling node voltages in a power network. A widely used solution for the problem of voltage regulation is based on adjusting the taps in under load tap changers (ULTCs) power transformers ... Keywords: Multi-objective optimization, Power distribution network, Power losses, Under load tap changers, Voltage regulation

Francisco G. Montoya; Raúl Baños; Consolación Gil; Antonio Espín; Alfredo Alcayde; Julio Gómez

2010-08-01T23:59:59.000Z

285

Elevated voltage level I.sub.DDQ failure testing of integrated circuits  

DOE Patents (OSTI)

Burn in testing of static CMOS IC's is eliminated by I.sub.DDQ testing at elevated voltage levels. These voltage levels are at least 25% higher than the normal operating voltage for the IC but are below voltage levels that would cause damage to the chip.

Righter, Alan W. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

286

Original article: Selective compensation of voltage harmonics in grid-connected microgrids  

Science Conference Proceedings (OSTI)

In this paper, a novel approach is proposed for selective compensation of main voltage harmonics in a grid-connected microgrid. The aim of compensation is to provide a high voltage quality at the point of common coupling (PCC). PCC voltage quality is ... Keywords: Distributed generator (DG), Grid-connected, Microgrid, Voltage harmonics compensation

Mehdi Savaghebi, Juan C. Vasquez, Alireza Jalilian, Josep M. Guerrero, Tzung-Lin Lee

2013-05-01T23:59:59.000Z

287

Requirements for a Standard Test to Rate the Durability of PV Modules at System Voltage (Presentation)  

DOE Green Energy (OSTI)

Degradation modes in photovoltaic modules under system bias voltage stress are described and classified.

Hacke, P.; Terwilliger, K.; Glick, S.; Kempe, M.; Kurtz, S.; Bennett, I.; Kloos, M.

2011-02-01T23:59:59.000Z

288

Voltage Stability/Security Assessment and On-Line Control: Volumes 1-4  

Science Conference Proceedings (OSTI)

To address growing utility concerns of voltage instability and possible voltage collapse, EPRI has developed a new voltage stability analysis package for large power systems, VSTAB. This off-line planning tool provides information on a utility power system's proximity to and mechanism of voltage instability.

1993-05-01T23:59:59.000Z

289

Impact of MOSFET's performance on its threshold voltage and its influence on design of MOS inverters  

Science Conference Proceedings (OSTI)

The aim of this paper is to research the impact of physical parameters which characterize the MOSFET transistors structure on the threshold voltage values and its influence on critical voltage values which characterize digital circuits that contain the ... Keywords: MOSFET parameters, critical values, doped density, enhancement-type NMOS, impurities, narrow-channel, propagation delay, short-channel, threshold voltage, voltage level

Milaim Zabeli; Nebi Caka; Myzafere Limani; Qamil Kabashi

2008-04-01T23:59:59.000Z

290

Effects of Distributed Energy Resources on Conservation Voltage Reduction (CVR)  

SciTech Connect

Conservation Voltage Reduction (CVR) is one of the cheapest technologies which can be intelligently leveraged to provide considerable energy savings. The addition of renewables in the form of distributed resources can affect the entire power system, but more importantly, affects the traditional substation control schemes at the distribution level. This paper looks at the effect on energy consumption, peak load reduction, and voltage profile changes due to the addition of distributed generation in a distribution feeder using combinations of volt var control. An IEEE 13-node system is used to simulate the various cases. Energy savings and peak load reduction for different simulation scenarios are compared.

Singh, Ruchi; Tuffner, Francis K.; Fuller, Jason C.; Schneider, Kevin P.

2011-10-10T23:59:59.000Z

291

Voltage Control Devices on the IEEE 8500 Node Test Feeder  

SciTech Connect

The IEEE Test Cases provide researchers with distribution system models that can be used to validate new analytic methods. The newest of these models is the 8500-node test feeder which contains multiple devices for voltage control. In addition to a substation regulator there are multiple inline regulators as well as capacitor banks. This paper will discuss the detail in which voltage control devises should be modeled when examining large distribution systems. This discussion will include issues associated with power flow analysis for a single time step as well as for time series analysis.

Schneider, Kevin P.; Fuller, Jason C.

2010-01-06T23:59:59.000Z

292

Method of determining the open circuit voltage of a battery in a closed circuit  

SciTech Connect

The open circuit voltage of a battery which is connected in a closed circuit is determined without breaking the circuit or causing voltage upsets therein. The closed circuit voltage across the battery and the current flowing through it are determined under normal load and then a fractional change is made in the load and the new current and voltage values determined. The open circuit voltage is then calculated, according to known principles, from the two sets of values.

Brown, William E. (Walnut Creek, CA)

1980-01-01T23:59:59.000Z

293

C17: Voltage Impulse Induced Bistable Magnetization Switching and ...  

Science Conference Proceedings (OSTI)

Non-violate dynamic magnetization switch was also realized by voltage impulse ... Concentric Nanoparticles Embedded in Low Temperature Synthesized TiO2 Films .... F2: Development of the On-Line Mechanical Property Prediction System for ... Sintered Nd-Fe-B Magnets by Transmission Electron Microscopy Analysis.

294

Ultra-compact Marx-type high-voltage generator  

DOE Patents (OSTI)

An ultra-compact Marx-type high-voltage generator includes individual high-performance components that are closely coupled and integrated into an extremely compact assembly. In one embodiment, a repetitively-switched, ultra-compact Marx generator includes low-profile, annular-shaped, high-voltage, ceramic capacitors with contoured edges and coplanar extended electrodes used for primary energy storage; low-profile, low-inductance, high-voltage, pressurized gas switches with compact gas envelopes suitably designed to be integrated with the annular capacitors; feed-forward, high-voltage, ceramic capacitors attached across successive switch-capacitor-switch stages to couple the necessary energy forward to sufficiently overvoltage the spark gap of the next in-line switch; optimally shaped electrodes and insulator surfaces to reduce electric field stresses in the weakest regions where dissimilar materials meet, and to spread the fields more evenly throughout the dielectric materials, allowing them to operate closer to their intrinsic breakdown levels; and uses manufacturing and assembly methods to integrate the capacitors and switches into stages that can be arranged into a low-profile Marx generator.

Goerz, David A. (Brentwood, CA); Wilson, Michael J. (Modesto, CA)

2000-01-01T23:59:59.000Z

295

High voltage gas insulated transmission line with continuous particle trapping  

DOE Patents (OSTI)

This invention provides a novel high voltage gas insulated transmission line utilizing insulating supports spaced at intervals with snap-in means for supporting a continuous trapping apparatus and said trapping apparatus having perforations and cutouts to facilitate trapping of contaminating particles and system flexibility.

Cookson, Alan H. (Pittsburgh, PA); Dale, Steinar J. (Monroeville, PA)

1983-01-01T23:59:59.000Z

296

Wire-Extrusion Process Disrupted By Voltage Sags  

Science Conference Proceedings (OSTI)

This PQTN Case Study investigates voltage sags originating from a utility distribution system at a wire-extrusion plant near Cleveland, Ohio that were causing a wire-drawing process to malfunction, resulting in broken tungsten wire and hours of time spent restarting the manufacturing process.

2003-12-31T23:59:59.000Z

297

Smart Solar Home System with Safety Device Low Voltage Alert  

Science Conference Proceedings (OSTI)

For many reasons Bangladeshi people are now using renewable energy. So, solar energy is the best renewable energy till now, in respect of Bangladesh. So using of solar system is common nowadays. Bangladesh Government has taken some steps to make solar ... Keywords: Smart Solar Home System (SSHS), Rooftop, Safety Device, Low voltage alert

Tawheed Hasan; Md. Faysal Nayan; Md. Asif Iqbal; Monzurul Islam

2012-03-01T23:59:59.000Z

298

Current isolating epitaxial buffer layers for high voltage photodiode array  

DOE Patents (OSTI)

An array of photodiodes in series on a common semi-insulating substrate has a non-conductive buffer layer between the photodiodes and the semi-insulating substrate. The buffer layer reduces current injection leakage between the photodiodes of the array and allows optical energy to be converted to high voltage electrical energy.

Morse, Jeffrey D. (Martinez, CA); Cooper, Gregory A. (Pleasant Hill, CA)

2002-01-01T23:59:59.000Z

299

Design of Low Voltage Low Power Operational Amplifier  

Science Conference Proceedings (OSTI)

With the demand of low power applications, running circuits with reduced supply voltage can be of great advantage. Integrated circuit designers start to face a power wall as the most difficult constraints in new technology and circuit development are ... Keywords: Op Amp, CMOS, LVLP

Manju Sandhu; Manju Bala

2012-01-01T23:59:59.000Z

300

Rank based dynamic voltage and frequency scaling fortiled graphics processors  

Science Conference Proceedings (OSTI)

With increasing interest in sophisticated graphics capabilities in mobile systems, energy consumption of graphics hardware is becoming a major design concern in addition to the traditional performance enhancement criteria. Our study of various modern ... Keywords: dynamic voltage and frequency scaling, graphics processor, low power, workload prediction

B.V.N Silpa; Gummidipudi Krishnaiah; Preeti Ranjan Panda

2010-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

High voltage bipolar-CMOS structure using porous silicon  

DOE Patents (OSTI)

A method for integrating a silicon-on-insulator device and a bulk bipolar device on a semiconductor body. The invention simultaneously forms the two regions for the silicon-on-insulator device and the bipolar device. The invention enables a high voltage CMOS power device to be located on the same chip as a bipolar logic device enabling smart power devices.

Guilinger, T.R.; Kelly, M.J.; Tsao, S.S.

1990-01-01T23:59:59.000Z

302

Analysis on DFIG Wind Power System Low-Voltage Ridethrough  

Science Conference Proceedings (OSTI)

Due to the double fed induction generator’s (DFIG) advantage of controlling active and reactive power independently and partial power converter, DFIG is becoming a popular type of wind power generation system. Nowadays, the grid code demands that ... Keywords: VSCF, DFIG, LVRT, Crowbar, Voltage sags

Yulong Wang; Jianlin Li; Shuju Hu; Honghua Xu

2009-04-01T23:59:59.000Z

303

Power and Voltage Smooth Control of Doubly Fed Induction Generator  

Science Conference Proceedings (OSTI)

Doubly-fed induction generator (DFIG) is the leading in wind power technology currently. In this paper, decoupling control of DFIG is studied and a new energy storage device is used in the smooth control of DFIG system's power and voltage. This new method ... Keywords: Doubly fed induction generator, Energy storage device, Decoupling control

An-Ren Ma, Cai-Xia Wang, Zhi-Wen Zhou, Tao Wu

2012-07-01T23:59:59.000Z

304

Low-voltage cathodoluminescence of europium-activated yttrium orthovanadate  

Science Conference Proceedings (OSTI)

Emissive flat panel display systems operating in full color demand higher performance at low voltages (ca. 501000 V) from cathodoluminescent (CL) phosphors than cathode ray tubes require. Hydrothermal synthesis has been suggested as a route to phosphors with improved efficiencies, lower voltage thresholds, and increased saturation power. This hypothesis was tested in europium-doped yttrium orthovanadate (YVO{sub 4}:Eu), an efficient, red emitting CL phosphor. The CL efficiency of YVO{sub 4}:Eu crystallized from aqueous solution at 200{degrees}C is relatively low until it is annealed. The distribution of particle sizes in the low-temperature phosphor is similar to that in material made via a solid-state route, but crystallites remain much smaller (ca. 400 {Angstrom}) until they are annealed. These observations, along with the anomalously strong dependence of CL intensity on europium concentration, support a model in which efficiency principally depends on crystallite size. CL efficiency of both solid state and hydrothermal YVO{sub 4}:Eu increases with voltage at constant power. Surface-bound electrons are likely the dominant influence on efficiency at voltages near threshold. Saturation power is independent of synthetic route. It is apparent that the CL properties of hydrothermally synthesized YVO{sub 4}:Eu are essentially the same as those of YVO{sub 4}:Eu produced via conventional, high-temperature routes.

Phillips, M.L.F.

1995-03-01T23:59:59.000Z

305

Control Techniques to Eliminate Voltage Emergencies in High Performance Processors  

E-Print Network (OSTI)

negligible impact on perfor­ mance and energy. With the ITRS roadmap predicting aggres­ sive drops in supply. At present it is difficult to design a high quality, low impedance power supply system, and industry trends in current variability, often re­ ferred to as the dI/dt problem, can cause supply voltage fluc­ tuations

Martonosi, Margaret

306

Control Techniques to Eliminate Voltage Emergencies in High Performance Processors  

E-Print Network (OSTI)

negligible impact on perfor- mance and energy. With the ITRS roadmap predicting aggres- sive drops in supply. At present it is difficult to design a high quality, low impedance power supply system, and industry trends in current variability, often re- ferred to as the dI/dt problem, can cause supply voltage fluc- tuations

Gupta, Rajiv

307

High Voltage Laboratory Testing of Femtosecond Laser Lightning Diversion  

Science Conference Proceedings (OSTI)

Lightning strikes cost the electric power industry an estimated 1 billion dollars annually in damage and lost revenue. One possible way of protecting critical and susceptible facilities from lightning strikes is to use lasers to trigger and divert lightning along a predetermined path. This report describes laboratory research on the use of ultrashort UV pulses and near IR pulses to trigger high voltage discharge.

1998-12-09T23:59:59.000Z

308

Stability issues in IC Low Drop Out voltage regulators  

E-Print Network (OSTI)

Performance issues of IC Low Drop Out (LDO) voltage regulators, with specific reference to stability, are discussed in this thesis. Evaluation of existing frequency compensation schemes and their performances across operating loads is presented. The problem of instability of the LDO voltage regulator at low Electo Static Resistance (ESR) of the load capacitors and the consequences of this problem are highlighted. As a solution to some of the discussed problems, an alternate LDO voltage regulator topology that is stable with low Electro Static Resistance (ESR) capacitive loads is presented. The proposed scheme, instead of relying on the zero generated by the load capacitor and its ESR combination for stability, generates a zero internally. The LDO voltage regulator is implemented and fabricated in AMI 0.5mm CMOS technology through MOSIS service. It is demonstrated that this scheme realizes robust frequency compensation, facilitates use of Multi Layer Ceramic Capacitors (MLCC) for load of LDO regulators, and improves transient response and noise performance. Test results from the prototype provide an evaluation of the most important parameters of the regulator: ground current, load regulation, line regulation, output noise and start-up time.

Chava, Krishna Chaitanya

2002-01-01T23:59:59.000Z

309

A variable voltage MPPT control method for photovoltaic generation system  

Science Conference Proceedings (OSTI)

To increase the output efficiency of a photovoltaic (PV) generation system it is important to have an efficient maximum power point tracking (MPPT) technique. This paper describes the analysis, design and implementation of an efficient tracking method ... Keywords: maximum power point tracking (MPPT), photovoltaic generation system, pulse-width-modulation (PWM), solar energy, variable voltage

Liu Liqun; Wang Zhixin

2009-04-01T23:59:59.000Z

310

Voltage stability/security assessment and on-line control  

SciTech Connect

Project RP3040-1 was initiated in 1989, and concluded with the release of the Voltage Stability analysis program, VSTAB, in 1992. VSTAB is a production grade program for voltage stability assessment of large complex power systems. During the course of the RP3040-1, much effort was spent in developing a clear understanding of voltage stability and in defining the special modeling and analytical techniques required to accurately capture the phenomenon through simulation. The result was the development of new steady state methods which can complement the dynamic simulation methods currently available with EPRI's Extended Transient/Midterm Stability Program (ETMSP). VSTAB uses an enhanced powerflow combined with a specially developed modal analysis algorithm to provide information regarding both the proximity to, and mechanism of, voltage instability. The program is fast, easy to use, and comprehensive in both modeling and analysis features. This Programmer's Manual documents the structure and code details of VSTAB. It is intended as a reference document for those required to maintain or enhance the VSTAB program. For details on analytical techniques used in the program, readers are directed to the VSTAB Application Guide and Final Report for project RP3040-1.

Morison, G.K.; Gao, B.; Hamadanizadeh, H. (Ontario Hydro, Toronto, ON (Canada))

1993-04-01T23:59:59.000Z

311

Hierarchical Control Scheme for Voltage Unbalance Compensation in Islanded Microgrids  

E-Print Network (OSTI)

Hierarchical Control Scheme for Voltage Unbalance Compensation in Islanded Microgrids Mehdi@et.aau.dk Abstract-- The concept of microgrid hierarchical control is presented, recently. In this paper, a hierarchical scheme which includes primary and secondary control levels is proposed for islanded microgrids

Vasquez, Juan Carlos

312

Low Beam Voltage, 10 MW, L-Band Cluster Klystron  

SciTech Connect

Conceptual design of a multi-beam klystron (MBK) for possible ILC and Project X applications is presented. The chief distinction between this MBK design and existing 10-MW MBK's is the low operating voltage of 60 kV. There are at least four compelling reasons that justify development at this time of a low-voltage MBK, namely (1) no pulse transformer; (2) no oil tank for high-voltage components and for the tube socket; (3) no high-voltage cables; and (4) modulator would be a compact 60-kV IGBT switching circuit. The proposed klystron consists of four clusters containing six beams each. The tube has common input and output cavities for all 24 beams, and individual gain cavities for each cluster. A closely related optional configuration, also for a 10 MW tube, would involve four totally independent cavity clusters with four independent input cavities and four 2.5 MW output ports, all within a common magnetic circuit. This option has appeal because the output waveguides would not require a controlled atmosphere, and because it would be easier to achieve phase and amplitude stability as required in individual SC accelerator cavities.

Teryaev, V.; /Novosibirsk, IYF; Yakovlev, V.P.; /Fermilab; Kazakov, S.; /KEK, Tsukuba; Hirshfield, J.L.; /Yale U. /Omega-P, New Haven

2009-05-01T23:59:59.000Z

313

High-voltage supply for neutron tubes in well-logging applications  

DOE Patents (OSTI)

A high voltage supply is provided for a neutron tube used in well logging. The biased pulse supply of the invention combines DC and full pulse techniques and produces a target voltage comprising a substantial negative DC bias component on which is superimposed a pulse whose negative peak provides the desired negative voltage level for the neutron tube. The target voltage is preferably generated using voltage doubling techniques and employing a voltage source which generates bipolar pulse pairs having an amplitude corresponding to the DC bias level.

Humphreys, D.R.

1982-09-15T23:59:59.000Z

314

Guidelines for Working at Voltages < 240 Volts  

NLE Websites -- All DOE Office Websites (Extended Search)

Guidelines for Working at Voltages < 240 Volts Guidelines for Working at Voltages < 240 Volts February 4, 2005---DRAFT NOTE: Working hot is a LAST ALTERNATIVE. Electrical hot work is defined as: Working on or near exposed conducting parts that are or might become energized at 50V or more. Refer to Electrical Safety Flowchart for Working On or Near Live Parts. Engineered methods to prevent exposed sources of 50V and greater are to be implemented wherever practical. Only QUALIFIED PERSONNEL {as defined in NFPA 70E Article 110.6(D) 2004 edition} as authorized by the CAT/supervisor/division can perform such work. Refer to Qualified Electrical Worker Flow Chart. Training requirements: ES&H 114 (LOTO) / ES&H 375 (NFPA 70E) / ES&H 371 (electrical worker) - Observe Electrical Safe Work Practices. Refer to

315

Methods for improving solar cell open circuit voltage  

DOE Patents (OSTI)

A method for producing a solar cell having an increased open circuit voltage. A layer of cadmium sulfide (CdS) produced by a chemical spray technique and having residual chlorides is exposed to a flow of hydrogen sulfide (H.sub.2 S) heated to a temperature of 400.degree.-600.degree. C. The residual chlorides are reduced and any remaining CdCl.sub.2 is converted to CdS. A heterojunction is formed over the CdS and electrodes are formed. Application of chromium as the positive electrode results in a further increase in the open circuit voltage available from the H.sub.2 S-treated solar cell.

Jordan, John F. (El Paso, TX); Singh, Vijay P. (El Paso, TX)

1979-01-01T23:59:59.000Z

316

Blocking diodes and fuses in low-voltage PV systems  

DOE Green Energy (OSTI)

Instructions and labels supplied with listed PV modules and the requirements of the National Electrical Code (NEC) dictate that a series fuse shall be used to protect the module against backfeed currents. Few of the hundreds of thousands of low-voltage (12, 24, and 48-volt) stand-alone photovoltaic (PV) power systems use series fuses on each module or string of modules. Tests and simulations at the Southwest Technology Development Institute (TDI) and at Sandia National Laboratories (SNL) have established that the absence of these fuses can pose significant fire and safety hazards even on 12-volt PV systems. If the system has sufficient backfeed voltage and current, it is possible that a ground fault in the wiring or inside a module can result in the destruction of a PV module.

Wiles, J.C. [New Mexico State Univ., Las Cruces, NM (United States). Southwest Technology Development Inst.; King, D.L. [Sandia National Labs., Albuquerque, NM (United States). Photovoltaic Systems R and D

1997-11-01T23:59:59.000Z

317

Evaluation of Conservation Voltage Reduction (CVR) on a National Level  

SciTech Connect

Conservation Voltage Reduction (CVR) is a reduction of energy consumption resulting from a reduction of feeder voltage. While there have been numerous CVR systems deployed in North America there has been little substantive analytic analysis of the effect; the majority of the published results are based on empirical field measurements. Since these results are based on empirical measurements it is difficult to extrapolate how this technology will behave on the various types of distribution feeders found throughout the nation. This report has utilized the Taxonomy of Prototypical feeder developed under the Modern Grid Initiative (MGI), now the Modern Grid Strategy (MGS), in order to estimate the benefits of CVR on multiple distribution feeder types. This information will then be used to determine an estimate of the national benefits of a wide scale deployment of CVR.

Schneider, Kevin P.; Fuller, Jason C.; Tuffner, Francis K.; Singh, Ruchi

2010-09-29T23:59:59.000Z

318

SRAM leakage suppression by minimizing standby supply voltage  

E-Print Network (OSTI)

Suppressing the leakage current in memories is critical in low-power design. By reducing the standby supply voltage (VDD) to its limit, which is the Data Retention Voltage (DRV), leakage power can be substantially reduced. This paper explores how low DRV can be in a standard low leakage SRAM module and analyzes how DRV is affected by parameters such as process variations, chip temperature, and transistor sizing. An analytical model for DRV as a function of process and design parameters is presented, and forms the base for further design space explorations. This model is verified using simulations as well as measurements from a 4KB SRAM chip in a 0.13?m technology. It is demonstrated that an SRAM cell state can be preserved at sub-300mV standby V DD, with more than 90 % leakage power savings. 1.

Huifang Qin; Yu Cao; Dejan Markovic; Andrei Vladimirescu; Jan Rabaey

2004-01-01T23:59:59.000Z

319

Analysis of Solar Cell Quality Using Voltage Metrics: Preprint  

DOE Green Energy (OSTI)

The highest efficiency solar cells provide both excellent voltage and current. Of these, the open-circuit voltage (Voc) is more frequently viewed as an indicator of the material quality. However, since the Voc also depends on the band gap of the material, the difference between the band gap and the Voc is a better metric for comparing material quality of unlike materials. To take this one step further, since Voc also depends on the shape of the absorption edge, we propose to use the ultimate metric: the difference between the measured Voc and the Voc calculated from the external quantum efficiency using a detailed balance approach. This metric is less sensitive to changes in cell design and definition of band gap. The paper defines how to implement this metric and demonstrates how it can be useful in tracking improvements in Voc, especially as Voc approaches its theoretical maximum.

Toberer, E. S.; Tamboli, A. C.; Steiner, M.; Kurtz, S.

2012-06-01T23:59:59.000Z

320

Field Guide: Compressors for High-Voltage Circuit Breakers  

Science Conference Proceedings (OSTI)

High-voltage circuit breakers (HVCBs) perform essential protection and control functions on power transmission networks. Circuit breakers have multiple components that must operate in concert in order for the breaker to perform properly. If one component, such as the air or hydraulic system, does not operate correctly, the circuit breaker may misoperate or fail, possibly resulting in equipment damage or an outageboth expensive consequences. To help utilities prevent such undesirable events, this field gu...

2010-12-22T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Field Guide: Compressors for High-Voltage Circuit Breakers  

Science Conference Proceedings (OSTI)

High-voltage circuit breakers (HVCBs) perform essential protection and control functions on power transmission networks. Circuit breakers have multiple components that must operate in concert in order for the breaker to perform properly. If one component, such as the air or hydraulic system, does not operate correctly, the circuit breaker may misoperate or fail, possibly resulting in equipment damage or an outage—both expensive consequences. To help ...

2012-12-14T23:59:59.000Z

322

Nano-Composite Dielectrics on Medium-Voltage Model Cables  

Science Conference Proceedings (OSTI)

EPRI early recognized the potential for nanotechnology in power distribution and started a program in 2003 to explore the possibilities of using the technology to enhance the properties of high-voltage (HV) cable dielectrics based on both polyethylene and on ethylene-propylene rubber. This research resulted in encouraging findings, particularly for a formulation based on functionalized silicon dioxide nanoparticles in a cross-linked polyethylene (XLPE) polymer. Following this success, EPRI entered into a...

2007-12-19T23:59:59.000Z

323

High Voltage Direct Current (HVDC) Transmission Reference Book  

Science Conference Proceedings (OSTI)

The EPRI High-Voltage Direct Current (HVDC) Transmission Reference Book is a state-of-the-art guidebook that provides transmission companies with a comprehensive, single source of technical information and guidance for designing, building, operating, and extending the life of HVDC transmission systems. The book joins the landmark series of EPRI power delivery reference books. These comprehensive guidebooks—each printed with a distinctive colored cover—document and distill the ...

2012-12-31T23:59:59.000Z

324

Field Guide: High-Voltage Circuit Breaker Compressors – 2013 Update  

Science Conference Proceedings (OSTI)

High-voltage circuit breakers (HVCBs) perform essential protection and control functions on power transmission networks. Circuit breaker mechanisms have multiple components that must operate in concert in order for the breaker to perform properly. If one component, such as the air or hydraulic system, does not operate correctly, the circuit breaker may mis-operate or fail. A circuit breaker mis-operation may cause equipment damage and outages—both ...

2013-12-19T23:59:59.000Z

325

Advanced Voltage Control Strategies for High Penetration of Distributed Generation  

Science Conference Proceedings (OSTI)

This research addresses advanced voltage control strategies for inverter-connected distributed generation. The emphasis is on photovoltaic (PV) generation, and results also apply to distributed wind, fuel cells, micro-turbines, and battery systems that are connected to the grid through an inverter. In related work, the Electric Power Research Institute (EPRI) identified a set of high-priority functions for distributed generation. These included reactive power control such as intelligent and autonomous vo...

2010-12-31T23:59:59.000Z

326

High-Voltage Direct Current Line Conductor Optimization  

Science Conference Proceedings (OSTI)

Overhead transmission lines are designed to last for 40 years. Many ac lines in service today in North America are 70 or more years old. This survival rate is a result of conservative utility design practices and detailed product specifications. This reliability record has occurred despite a wide range of conductor types and sizes. In the present transmission system, there are far fewer high-voltage direct current (HVDC) lines, but those that have been designed and built have been similarly successful in...

2011-12-21T23:59:59.000Z

327

Fiber optic current monitor for high-voltage applications  

DOE Patents (OSTI)

A current monitor which derives its power from the conductor being measured for bidirectionally measuring the magnitude of current (from DC to above 50 khz) flowing through a conductor across which a relatively high level DC voltage is applied, includes a pair of identical transmitter modules connected in opposite polarity to one another in series with the conductor being monitored, for producing from one module a first light signal having an intensity directly proportional to the magnitude of current flowing in one direction through the conductor during one period of time, and from the other module a second light signal having an intensity directly proportional to the magnitude of current flowing in the opposite direction through the conductor during another period of time, and a receiver located in a safe area remote from the high voltage area for receiving the first and second light signals, and converting the same to first and second voltage signals having levels indicative of the magnitude of current being measured at a given time. 6 figs.

Renda, G.F.

1992-04-21T23:59:59.000Z

328

765kV Transmission line Voltage gradient  

E-Print Network (OSTI)

Corona ring Transmission lines Nowadays, due to the ever increasing energy consumption and power supply optimization, it is required to construct new power plants, substations and transmission lines. In Iran, also, because of increasing demand for electrical energy, for a significant power loss reduction in power transmission over long distances, and to construct high transmission lines that lead to reduction in the economic costs of transmission lines, the transmission lines must be considered at extra high voltage (EHV) levels. These EHV levels should be compared with the low voltage levels in order to extract the benefits. Therefore, in this paper, a review has been conducted on the types of 765 kV transmission lines used in different countries and a comparison between them and the low voltage levels have been performed. Accordingly, the advantages of EHV transmission lines are summarized. Finally, designing a line of 765 kV single-circuit with 6 conductors per bundle based on existing standards is presented.

unknown authors

2012-01-01T23:59:59.000Z

329

Advanced Gate Drive for the SNS High Voltage Converter Modulator  

SciTech Connect

SLAC National Accelerator Laboratory is developing a next generation H-bridge switch plate [1], a critical component of the SNS High Voltage Converter Modulator [2]. As part of that effort, a new IGBT gate driver has been developed. The drivers are an integral part of the switch plate, which are essential to ensuring fault-tolerant, high-performance operation of the modulator. The redesigned driver improves upon the existing gate drive in several ways. The new gate driver has improved fault detection and suppression capabilities; suppression of shoot-through and over-voltage conditions, monitoring of dI/dt and Vce(sat) for fast over-current detection and suppression, and redundant power isolation are some of the added features. In addition, triggering insertion delay is reduced by a factor of four compared to the existing driver. This paper details the design and performance of the new IGBT gate driver. A simplified schematic and description of the construction are included. The operation of the fast over-current detection circuits, active IGBT over-voltage protection circuit, shoot-through prevention circuitry, and control power isolation breakdown detection circuit are discussed.

Nguyen, M.N.; Burkhart, C.; Kemp, M.A.; /SLAC; Anderson, D.E.; /Oak Ridge

2009-05-07T23:59:59.000Z

330

Understanding the unbalanced-voltage problem in wind turbine generation  

DOE Green Energy (OSTI)

Most wind turbines are equipped with line-connected induction generators. Induction generators are very attractive as wind turbine generators due to their low cost, ruggedness and the need for little or no maintenance. At constant frequency, the induction generator operates in a small range of speeds and, therefore, it operated with a small range of slips with respect to synchronous speed. Compared to a synchronous generator, an induction generator provides lower stiffness, thus alleviating the mechanical stress. In a weak power system network, an unbalanced load at the distribution lines can cause unbalanced voltage conditions. If an induction generator is connected to an unbalanced voltage, the resulting stator current will be unbalanced. The unbalanced current creates unequal heating (hot spots) on the stator winding. The heat may increase the winding temperature, which degrades the insulation of the winding, i.e., the life expectancy of the winding. Unbalanced currents also create torque pulsation on the shaft resulting in audible noise and extra mechanical stress. This paper explores the unbalanced voltage problem in induction generators. The levels of unbalance and the loads are varied. Experimental and predicted results are presented in this paper.

Muljadi, E.; Butterfield, C.P.; Batan, T.; Yildirim, D.

2000-02-28T23:59:59.000Z

331

Ultra-low voltage resonant tunnelling diode electroabsorption modulator  

E-Print Network (OSTI)

Embedding a double barrier resonant tunnelling diode (RTD) in an unipolar InGaAlAs optical waveguide gives rise to a very low driving voltage electroabsorption modulator (EAM) at optical wavelengths around 1550 nm. The presence of the RTD within the waveguide core introduces high non-linearity and negative differential resistance in the current-voltage (I-V) characteristic of the waveguide. This makes the electric field distribution across the waveguide core strongly dependent on the bias voltage: when the current decreases from the peak to the valley there is an increase of the electric field across the depleted core. The electric field enhancement in the core-depleted layer causes the Franz-Keldysh absorption band-edge to red shift, which is responsible for the electroabsorption effect. High frequency ac signals as low as 100 mV can induce electric field high speed switching, producing substantial light modulation (up to 15 dB) at photon energies slightly lower than the waveguide core band-gap energy. The k...

Figueiredo, J M L; Stanley, C R

2002-01-01T23:59:59.000Z

332

Near independence of OLED operating voltage on transport layer thickness  

SciTech Connect

We report organic light emitting devices (OLEDs) with weak drive voltage dependence on the thickness of the hole transport layer (HTL) for thicknesses up to 1150 Å using the N,N?-Bis(naphthalen-1-yl)-N,N?-bis(phenyl)-benzidine (?-NPD) and N,N'-bis(3-methyl phenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'diamine (TPD), both of which have hole mobilities in the range of 2 × 10-3 cm2V-1s-1. Lower mobility HTL materials show larger operating voltage dependence on thickness. The near independence of the operating voltage for high mobility transport material thickness was only observed when the energy barrier for charge injection into the transport material was minimized. To ensure low injection barriers, a thin film of 2-(3-(adamantan-1-yl)propyl)-3,5,6-trifluorotetracyanoquinodimethane (F3TCNQ-Adl) was cast from solution onto the ITO surface. These results indicate that thick transport layers can be integrated into OLED stacks without the need for bulk conductivity doping.

Swensen, James S.; Wang, Liang (Frank) [Frank; Polikarpov, Evgueni; Rainbolt, James E.; Koech, Phillip K.; Cosimbescu, Lelia; Padmaperuma, Asanga B.

2013-01-01T23:59:59.000Z

333

Research on Low-Voltage Ride-Through Technology of Doubly-Fed VSCF Wind Power Generation System  

Science Conference Proceedings (OSTI)

Currently, some of the variable speed wind turbine on market have some low-voltage through capacity?LVRT?, but do not have dynamic reactive power support capacity under fault. DFIG can’t provide dynamic voltage support, in addition, ... Keywords: wind power, voltage dip, low voltage ride-through (LVRT), transient voltage control, rotor-side converter

Bao Wei; Yin Zhongdong

2009-10-01T23:59:59.000Z

334

Interline photovoltaic (I-PV) power plants for voltage unbalance compensation  

E-Print Network (OSTI)

This paper proposes a stationary-frame control method for voltage unbalance compensation using Interline Photovoltaic (I-PV) power system. I-PV power systems are controlled to compensate voltage unbalance autonomously. The ...

Moawwad, Ahmed

335

BB5, Nearly Ideal Current-Voltage Characteristics of Schottky Barrier ...  

Science Conference Proceedings (OSTI)

Recently, high-quality GaN free-standing substrates are available by various methods. ... Current-voltage (I-V) characteristics and capacitance-voltage (C-V) ...

336

A low-voltage zero-crossing-based delta-sigma analog-to-digital converter  

E-Print Network (OSTI)

A zero-crossing-based (ZCB) switched-capacitor technique is presented for operation under low power supply voltages without gate boosting. Voltage ramp generators maintain common-mode level at each integrator output. ...

Guyton, Matthew C. (Matthew Christopher)

2010-01-01T23:59:59.000Z

337

A low-noise bandgap voltage reference employing dynamic element matching  

E-Print Network (OSTI)

Bandgap voltages references are widely used in IC design, but are sensitive to low-frequency noise and component mismatch. This thesis describes the design and testing of a new IC voltage reference that targets these issues ...

Herbst, Steven (Steven G.)

2011-01-01T23:59:59.000Z

338

Voltage holding study of 1 MeV accelerator for ITER neutral beam injectora)  

Science Conference Proceedings (OSTI)

Voltage holding test on MeV accelerator indicated that sustainable voltage was a half of that of ideal quasi-Rogowski electrode. It was suggested that the emission of the clumps is enhanced by a local electric field concentration

M. Taniguchi; M. Kashiwagi; N. Umeda; M. Dairaku; J. Takemoto; H. Tobari; K. Tsuchida; H. Yamanaka; K. Watanabe; A. Kojima; M. Hanada; K. Sakamoto; T. Inoue

2012-01-01T23:59:59.000Z

339

Monitoring Volume Transport through Measurement of Cable Voltage across the Korea Strait  

Science Conference Proceedings (OSTI)

Voltage induced by the Tsushima Current on an abandoned submarine telephone cable between Pusan, Korea, and Hamada, Japan, has been measured since March 1998 in order to monitor the volume transport through the Korea Strait. Voltage has a good ...

Kuh Kim; Sang Jin Lyu; Young-Gyu Kim; Byung Ho Choi; Keisuke Taira; Henry T. Perkins; William J. Teague; Jeffrey W. Book

2004-04-01T23:59:59.000Z

340

Lipon Coatings for High Voltage and High Temperature Li-Ion ...  

use of high-capacity and high-voltage cathode materials, but charging to voltages approaching 4.5-5V invariably causes rapid loss of capacity with cycling.

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Strategies for Voltage Control and Transient Stability Assessment  

SciTech Connect

As wind generation grows, its influence on power system performance will becoming increasingly noticeable. Wind generation di#11;ffers from traditional forms of generation in numerous ways though, motivating the need to reconsider the usual approaches to power system assessment and performance enhancement. The project has investigated the impact of wind generation on transient stability and voltage control, identifying and addressing issues at three distinct levels of the power system: 1) at the device level, the physical characteristics of wind turbine generators (WTGs) are quite unlike those of synchronous machines, 2) at the wind-farm level, the provision of reactive support is achieved through coordination of numerous dissimilar devices, rather than straightforward generator control, and 3) from a systems perspective, the location of wind-farms on the sub-transmission network, coupled with the variability inherent in their power output, can cause complex voltage control issues. The project has sought to develop a thorough understanding of the dynamic behaviour of type-3 WTGs, and in particular the WECC generic model. The behaviour of such models is governed by interactions between the continuous dynamics of state variables and discrete events associated with limits. It was shown that these interactions can be quite complex, and may lead to switching deadlock that prevents continuation of the trajectory. Switching hysteresis was proposed for eliminating deadlock situations. Various type-3 WTG models include control blocks that duplicate integrators. It was shown that this leads to non-uniqueness in the conditions governing steady-state, and may result in pre- and post-disturbance equilibria not coinciding. It also gives rise to a zero eigenvalue in the linearized WTG model. In order to eliminate the anomalous behaviour revealed through this investigation, WECC has now released a new generic model for type-3 WTGs. Wind-farms typically incorporate a variety of voltage control equipment including tapchanging transformers, switched capacitors, SVCs, STATCOMs and the WTGs themselves. The project has considered the coordinated control of this equipment, and has addressed a range of issues that arise in wind-farm operation. The #12;first concerns the ability of WTGs to meet reactive power requirements when voltage saturation in the collector network restricts the reactive power availability of individual generators. Secondly, dynamic interactions between voltage regulating devices have been investigated. It was found that under certain realistic conditions, tap-changing transformers may exhibit instability. In order to meet cost, maintenance, fault tolerance and other requirements, it is desirable for voltage control equipment to be treated as an integrated system rather than as independent devices. The resulting high-level scheduling of wind-farm reactive support has been investigated. In addressing this control problem, several forms of future information were considered, including exact future knowledge and stochastic predictions. Deterministic and Stochastic Dynamic Programming techniques were used in the development of control algorithms. The results demonstrated that while exact future knowledge is very useful, simple prediction methods yield little bene#12;fit. The integration of inherently variable wind generation into weak grids, particularly subtransmission networks that are characterized by low X=R ratios, aff#11;ects bus voltages, regulating devices and line flows. The meshed structure of these networks adds to the complexity, especially when wind generation is distributed across multiple nodes. A range of techniques have been considered for analyzing the impact of wind variability on weak grids. Sensitivity analysis, based on the power-flow Jacobian, was used to highlight sections of a system that are most severely a#11;ffected by wind-power variations. A continuation power flow was used to determine parameter changes that reduce the impact of wind-power variability. It was also used to explore interactions betw

Hiskens, Ian A.

2013-09-25T23:59:59.000Z

342

Technology Assessment and Application Guide for the Utility Systems Technologies Voltage Sag Fighter  

Science Conference Proceedings (OSTI)

Voltage sag, a disturbance in a power system defined as a decrease in root mean square (RMS) voltage magnitude lasting from 0.5 to 30 cycles, has been identified as the most prevalent power disturbance experienced by industrial customers. The higher frequency of voltage sages makes them inherently more costly than interruptions since fault-induced, short-duration voltage variations can result in costly loss of production, damaged materials, repair and cleaning of equipment, and lost business opportunitie...

2010-11-29T23:59:59.000Z

343

A Hybrid Framework for Voltage Security Assessment Integrating Simulation and Measurement Based Approaches  

Science Conference Proceedings (OSTI)

Voltage stability is the ability of a power system to maintain adequate voltage magnitudes at buses, which is a major concern in daily power system operations and a leading factor to limit power transfers in a prevailing open-access environment. Currently, simulation-based voltage security assessment (VSA) tools are applied widely by electric utilities to analyze either steady-state or transient voltage stability issues. Those VSA tools can help operators foresee the next critical ...

2012-12-31T23:59:59.000Z

344

A high-voltage low-power DC-DC buck regulator for automotive applications  

Science Conference Proceedings (OSTI)

This work presents a High-Voltage Low-Power CMOS DC-DC buck regulator for automotive applications. The overall system, including the high and low voltage analog devices, the power MOS and the low voltage digital devices, was realized in the Austriamicrosystems ... Keywords: DC-DC regulator, buck converter, current control, low quiscent current, pulse frequency modulation

G. Pasetti; L. Fanucci; R. Serventi

2010-03-01T23:59:59.000Z

345

Intelligent robust control of hybrid distributed generation system under voltage sag  

Science Conference Proceedings (OSTI)

In this paper, design of control strategy for hybrid fuel cell/energy storage distributed power generation system during voltage sag has been presented. The proposed control strategy allows hybrid distributed generation system works properly when a voltage ... Keywords: Energy storage, Fuel cell, Fuzzy sliding control, Hybrid distributed generation, Lyapanov, Neuro-fuzzy, Voltage sag

Amin Hajizadeh; Masoud Aliakbar Golkar

2010-12-01T23:59:59.000Z

346

Connectivity and Bidirectional Energy Transfer in DC Microgrid Featuring Different Voltage Characteristics  

Science Conference Proceedings (OSTI)

In this paper, the connectivity issues related to linking two DC buses featuring different voltage characteristics, in terms of voltage level and ripple, in a DC micro grid are identified, analyzed and discussed. A controlled DC-DC converter was used ... Keywords: Bidirectional energy transfer, buck-boost converter, DC distribution systems, DC microgrids, voltage ripple

Mustafa Farhadi, Ahmed Mohamed, Osama Mohammed

2013-04-01T23:59:59.000Z

347

Modeling and simulation of new configuration of dynamic voltage restorer for power quality improvement  

Science Conference Proceedings (OSTI)

The dynamic voltage restorer (DVR) is a custom device that is used to maintain the voltage at the load terminals from various power quality problems from a disturbed incoming supply. In this paper, a novel control strategy is described for mitigation ... Keywords: custom device, dynamic voltage restorer (DVR), power quality, sags, sensitive loads, swells

Rosli Omar; Nasrudin Abdul Rahim

2011-04-01T23:59:59.000Z

348

Currents' Physical Components (CPC) In Circuits with Nonsinusoidal Voltages and Currents  

E-Print Network (OSTI)

voltages and currents. It is true only for balanced loads supplied with a symmetrical voltage. However{ || || || || || || }P u u uY Y Y+ + . (20) The supply voltage is sinusoidal and symmetrical, thus RS ST TR R for energy permanent conversion in the load with power P. The remaining part of the supply current, i ­ ia

Czarnecki, Leszek S.

349

Energy Minimization Using Multiple Supply Voltages Jui-Ming Chang and Massoud Pedram  

E-Print Network (OSTI)

Energy Minimization Using Multiple Supply Voltages Jui-Ming Chang and Massoud Pedram Department and energy costs of these level shifters must be taken into account when comparing a multiple-supply voltage a dynamic programming technique for solv- ing the multiple supply voltage scheduling problem in both non

Pedram, Massoud

350

Charging-choke circuit with a crowbar for precision control of voltage  

DOE Patents (OSTI)

The operation of a circuit using a charging choke to obtain dc voltages is improved by constructing the circuit to be capable of producing a higher voltage than the desired value and crowbarring the charging choke when the load voltage reaches the desired value.

Praeg, W.F.

1975-11-25T23:59:59.000Z

351

Analysis the operation of DVR in voltage sag mitigation using EMTP  

Science Conference Proceedings (OSTI)

According to the reports, voltage sag is the most probable voltage problem in the network. As the number of sensitive loads increases rapidly the demand for a reliable and cost effective solution also has been increased. In this paper we are going to ... Keywords: DVR, custom power, distribution network, voltage sag

H. Monsef; B. Tamimi

2005-03-01T23:59:59.000Z

352

Voltage control of emerging distribution systems with induction motor loads using robust LQG approach  

E-Print Network (OSTI)

mode" in emerging distribution systems. The small-signal stability analysis indicates that load voltageVoltage control of emerging distribution systems with induction motor loads using robust LQG has significant performance to improve the voltage profile of the distributed generation system

Pota, Himanshu Roy

353

CMOS flash analog-to-digital converter for high speed and low voltage applications  

Science Conference Proceedings (OSTI)

A CMOS flash analog-to-digital converter (ADC) designed for high speed and low voltage is presented. Using the Threshold Inverter Quantization (TIQ) comparator technique, a flash ADC can be applied to low supply voltage. A fat tree encoder that has signal ... Keywords: TIQ comparator, analog-to-digital converter, fat tree encoder, flash ADC, high speed, low voltage

Jincheol Yoo; Kyusun Choi; Jahan Ghaznavi

2003-04-01T23:59:59.000Z

354

A model for the critical voltage for electrical degradation of GaN high electron mobility transistors  

E-Print Network (OSTI)

We have found that there is a critical drain-to-gate voltage beyond which GaN high-electron mobility transistors start to degrade in electrical-stress experiments. The critical voltage depends on the detailed voltage biasing ...

Joh, Jungwoo

355

Nuclear Maintenance Applications Center: Post-Trip Voltage Prediction at Nuclear and Other Generating Stations  

Science Conference Proceedings (OSTI)

The objective of this Electric Power Research Institute (EPRI) project is to investigate the possibility of predicting the switchyard voltage in a nuclear power plant (NPP) following a trip of a nuclear unit. Two methods of post-trip voltage prediction are investigated. The first method, called the V-Q method, uses minimal local plant information (such as unit operating conditionsactive and reactive power output and pre-trip voltage) to predict post-trip voltage based on the sensitivity of voltage to the...

2009-06-30T23:59:59.000Z

356

Voltage Node Arcing in the ICRH Antenna Vacuum Transmission Lines at JET  

Science Conference Proceedings (OSTI)

The observation of parasitic low-VSWR activity during operations of JET RF plant and the damage caused by arcing at the voltage-node in the vacuum transmission line (VTL) in 2004 highlight the importance of the problem of low-voltage breakdown in the ICRH systems. Simulations demonstrate little response of the RF circuit to the voltage-node arcing which explains why it remains largely unnoticed and complicates the design of protection systems. Analysis of the damage pattern produced by the voltage-node arcing suggests that multipactor-related phenomena occurring at elevated voltage thresholds in conditions of unfavorable VTL geometry are most plausible arc-provoking factors.

Monakhov, I.; Graham, M.; Mayoral, M.-L.; Nicholls, K.; Walden, A. [Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Bobkov, V. [Max-Planck Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)

2007-09-28T23:59:59.000Z

357

Induction of nuclear fission by high-voltage application  

E-Print Network (OSTI)

In nuclear power generation, fissile materials are mainly used. For example, $U^{235}$ is fissile and therefore quite essential for use of nuclear energy. However, the material $U^{235}$ has very small natural abundance less than 1 %. We should seek possibility of utilizing fissionable materials such as $U^{238}$ because natural abundance of such fissionable materials is generally much larger than fissile ones. In this paper, we show that thermal neutrons with vanishing kinetic energy can induce nuclear fission when high voltage is applied to fissionable materials. To obtain this result, we use the liquid-drop model for nuclei. Finally, we propose how fissionable materials can be utilized.

Hirokazu Maruyama

2007-11-20T23:59:59.000Z

358

Light-weight DC to very high voltage DC converter  

DOE Patents (OSTI)

A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

Druce, Robert L. (Union City, CA); Kirbie, Hugh C. (Dublin, CA); Newton, Mark A. (Livermore, CA)

1998-01-01T23:59:59.000Z

359

Light-weight DC to very high voltage DC converter  

DOE Patents (OSTI)

A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

Druce, R.L.; Kirbie, H.C.; Newton, M.A.

1998-06-30T23:59:59.000Z

360

Light-induced voltage alteration for integrated circuit analysis  

DOE Patents (OSTI)

An apparatus and method are described for analyzing an integrated circuit (IC), The invention uses a focused light beam that is scanned over a surface of the IC to generate a light-induced voltage alteration (LIVA) signal for analysis of the IC, The LIVA signal may be used to generate an image of the IC showing the location of any defects in the IC; and it may be further used to image and control the logic states of the IC. The invention has uses for IC failure analysis, for the development of ICs, for production-line inspection of ICs, and for qualification of ICs.

Cole, Jr., Edward I. (Albuquerque, NM); Soden, Jerry M. (Placitas, NM)

1995-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Self-monitoring high voltage transmission line suspension insulator  

DOE Patents (OSTI)

A high voltage transmission line suspension insulator (18 or 22) which monitors its own dielectric integrity. A dielectric rod (10) has one larger diameter end fitting attachable to a transmission line and another larger diameter end fitting attachable to a support tower. The rod is enclosed in a dielectric tube (14) which is hermetically sealed to the rod's end fittings such that a liquidtight space (20) is formed between the rod and the tube. A pressurized dielectric liquid is placed within that space. A discoloring dye placed within this space is used to detect the loss of the pressurized liquid.

Stemler, Gary E. (Vancouver, WA); Scott, Donald N. (Vancouver, WA)

1981-01-01T23:59:59.000Z

362

Worldwide reliability surveys of high voltage circuit breakers  

Science Conference Proceedings (OSTI)

This article reports on the results of two CIGRE 13.06 Working Group worldwide surveys of the reliability of high voltage circuit breakers, 63 kV and above. The first inquiry included 78,000 breaker-years of ``in service data`` from 102 utilities in 22 countries during the years 1974--1977 and included all interrupting technologies. The second inquiry included 70,708 breaker-years from 132 utilities in 22 countries for the years 1988--1991 and only included single-pressure SF6 breakers, because this is what most utilities are now buying. Thirty-one US utilities submitted data.

Heising, C.R.

1995-05-01T23:59:59.000Z

363

Outdoor PV Module Degradation of Current-Voltage Parameters: Preprint  

DOE Green Energy (OSTI)

Photovoltaic (PV) module degradation rate analysis quantifies the loss of PV power output over time and is useful for estimating the impact of degradation on the cost of energy. An understanding of the degradation of all current-voltage (I-V) parameters helps to determine the cause of the degradation and also gives useful information for the design of the system. This study reports on data collected from 12 distinct mono- and poly-crystalline modules deployed at the National Renewable Energy Laboratory (NREL) in Golden, Colorado. Most modules investigated showed < 0.5%/year decrease in maximum power due to short-circuit current decline.

Smith, R. M.; Jordan, D. C.; Kurtz, S. R.

2012-04-01T23:59:59.000Z

364

High-Voltage Power Supply System for Laser Isotope Separation  

SciTech Connect

This report presents several concepts for Laser High-Voltage Power Supply (HVPS) Systems for a Laser Isotope Separation facility. Selection of equipments and their arrangement into operational systems is based on proven designs and on application concepts now being developed. This report has identified a number of alternative system arrangements and has provided preliminary cost estimates for each. The report includes a recommendation for follow-on studies that will further define the optimum Laser HVPS Systems. Brief descriptions are given of Modulator/Regulator circuit trade-offs, system control interfaces, and their impact on costs.

Ketaily, E.C.; Buckner, R.P.; Uhrik, R.L.

1979-06-26T23:59:59.000Z

365

High Voltage Direct Current Live Line and Insulator Testing  

Science Conference Proceedings (OSTI)

This report has two main parts. The focus of the first part is on live work in overhead high-voltage direct current (HVDC) lines operating above 100 kV dc. It does not address issues related to lines for electric transport that typically operate below 60 kV dc worldwide. In addition, this first part of the report is not a detailed treatise on live work but, rather, addresses the main issues related to dc live work. More detailed information on the general topic of live work can be found in the references...

2011-12-23T23:59:59.000Z

366

Development of static and simulation programs for voltage stability studies of bulk power system  

SciTech Connect

In the analysis and evaluation of voltage stability, it is necessary to accurately identify the stability margin at each load point under specific system configuration or power balance condition. Voltage stability margin can be basically identified by the multi-solution load flow calculation method. When predicted by this static analysis that voltage instability may occur, time domain simulation will be required which includes the models of various control equipments related with system voltage profile. To deal with this, the following two analytical computer codes shown below were developed. (1) Voltage stability static analysis computer code employing a new load flow calculation method. (2) Time domain long term simulation computer code for voltage stability. These computer codes can also calculate the voltage stability index at each load point which is based on the margin to the stability power limit at each load point. The practicality of these codes developed were verified by applying to the IEEE-118 test system.

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

1997-02-01T23:59:59.000Z

367

An accurate continuous calibration system for high voltage current transformer  

SciTech Connect

A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site.

Tong Yue; Li Binhong [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province (China)

2011-02-15T23:59:59.000Z

368

Commercialization of Medium Voltage HTS Triax TM Cable Systems  

SciTech Connect

The original project scope that was established in 2007 aimed to install a 1,700 meter (1.1 mile) medium voltage HTS Triax{TM} cable system into the utility grid in New Orleans, LA. In 2010, however, the utility partner withdrew from the project, so the 1,700 meter cable installation was cancelled and the scope of work was reduced. The work then concentrated on the specific barriers to commercialization of HTS cable technology. The modified scope included long-length HTS cable design and testing, high voltage factory test development, optimized cooling system development, and HTS cable life-cycle analysis. In 2012, Southwire again analyzed the market for HTS cables and deemed the near term market acceptance to be low. The scope of work was further reduced to the completion of tasks already started and to testing of the existing HTS cable system in Columbus, OH. The work completed under the project included: • Long-length cable modeling and analysis • HTS wire evaluation and testing • Cable testing for AC losses • Optimized cooling system design • Life cycle testing of the HTS cable in Columbus, OH • Project management. The 200 meter long HTS Triax{TM} cable in Columbus, OH was incorporated into the project under the initial scope changes as a test bed for life cycle testing as well as the site for an optimized HTS cable cooling system. The Columbus cable utilizes the HTS TriaxTM design, so it provided an economical tool for these of the project tasks.

Knoll, David

2012-12-31T23:59:59.000Z

369

Miniature UV lamp excited by subnanosecond voltage pulses  

SciTech Connect

Energy, time, and spectral characteristics of emission of the second positive system of N{sub 2} molecules in gaseous nitrogen, Ar - N{sub 2} mixture, and air are investigated. An FPG-10 generator with voltage pulse FWHM of 200 and 400 ps and matched-load amplitudes of 14 and 6 kV, respectively, is used to excite gases. It is shown that excitation can be performed in two regimes using this generator. In the first regime a diffuse discharge is formed at atmospheric pressure, which opens ways to design miniature nanosecond UV lamps. A diffuse discharge is formed due to the generation of runaway electrons, with the aid of electrodes having a small radius of curvature and voltage pulses with a sharp leading edge. In the second regime an elevated average radiation power is obtained under excitation by a barrier discharge. However, the operating pressure is lower in this case, and the sizes of the emitting region and the UV pulse width significantly increase. (laser applications and other topics in quantum electronics)

Erofeev, M V; Baksht, E Kh; Tarasenko, Viktor F; Shut'ko, Yu V [Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation)

2010-08-27T23:59:59.000Z

370

Bi-directional power control system for voltage converter  

DOE Patents (OSTI)

A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals.

Garrigan, Neil Richard (Niskayuna, NY); King, Robert Dean (Schenectady, NY); Schwartz, James Edward (Slingerlands, NY)

1999-01-01T23:59:59.000Z

371

Bi-directional power control system for voltage converter  

DOE Patents (OSTI)

A control system for a voltage converter includes: a power comparator for comparing a power signal on input terminals of the converter with a commanded power signal and producing a power comparison signal; a power regulator for transforming the power comparison signal to a commanded current signal; a current comparator for comparing the commanded current signal with a measured current signal on output terminals of the converter and producing a current comparison signal; a current regulator for transforming the current comparison signal to a pulse width modulator (PWM) duty cycle command signal; and a PWM for using the PWM duty cycle command signal to control electrical switches of the converter. The control system may further include: a command multiplier for converting a voltage signal across the output terminals of the converter to a gain signal having a value between zero (0) and unity (1), and a power multiplier for multiplying the commanded power signal by the gain signal to provide a limited commanded power signal, wherein power comparator compares the limited commanded power signal with the power signal on the input terminals. 10 figs.

Garrigan, N.R.; King, R.D.; Schwartz, J.E.

1999-05-11T23:59:59.000Z

372

Experiment and Simulation of Dynamic Voltage Regulation in Multiple Distributed Energy Resources Systems  

Science Conference Proceedings (OSTI)

Distributed energy (DE) resources are power sources located near load centers and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide reactive power (along with active power) locally for dynamic voltage regulation. In this paper, a synchronous condenser and a microturbine with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Developed voltage control schemes for the inverter and the synchronous condenser are presented. Experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously although the dynamic response of the inverter is much faster than the synchronous condenser. In a system with multiple DEs performing local voltage regulation, the interaction between the DEs is studied. The simulation results show the relationship between the voltages in the system and the reactive power required for the voltage regulation. Also, integrated voltage regulation (multiple DEs performing voltage regulation) can increase the voltage regulation capability of DEs and reduce the capital and operating costs.

Xu, Yan [ORNL; Li, Fangxing [ORNL; Kueck, John D [ORNL; Rizy, D Tom [ORNL

2007-01-01T23:59:59.000Z

373

System and method for floating-substrate passive voltage contrast  

DOE Patents (OSTI)

A passive voltage contrast (PVC) system and method are disclosed for analyzing ICs to locate defects and failure mechanisms. During analysis a device side of a semiconductor die containing the IC is maintained in an electrically-floating condition without any ground electrical connection while a charged particle beam is scanned over the device side. Secondary particle emission from the device side of the IC is detected to form an image of device features, including electrical vias connected to transistor gates or to other structures in the IC. A difference in image contrast allows the defects or failure mechanisms be pinpointed. Varying the scan rate can, in some instances, produce an image reversal to facilitate precisely locating the defects or failure mechanisms in the IC. The system and method are useful for failure analysis of ICs formed on substrates (e.g. bulk semiconductor substrates and SOI substrates) and other types of structures.

Jenkins, Mark W. (Albuquerque, NM); Cole, Jr., Edward I. (Albuquerque, NM); Tangyunyong, Paiboon (Albuquerque, NM); Soden, Jerry M. (Placitas, NM); Walraven, Jeremy A. (Albuquerque, NM); Pimentel, Alejandro A. (Albuquerque, NM)

2009-04-28T23:59:59.000Z

374

High-voltage atmospheric breakdown across intervening rutile dielectrics.  

SciTech Connect

This report documents work conducted in FY13 on electrical discharge experiments performed to develop predictive computational models of the fundamental processes of surface breakdown in the vicinity of high-permittivity material interfaces. Further, experiments were conducted to determine if free carrier electrons could be excited into the conduction band thus lowering the effective breakdown voltage when UV photons (4.66 eV) from a high energy pulsed laser were incident on the rutile sample. This report documents the numerical approach, the experimental setup, and summarizes the data and simulations. Lastly, it describes the path forward and challenges that must be overcome in order to improve future experiments for characterizing the breakdown behavior for rutile.

Williamson, Kenneth Martin; Simpson, Sean; Coats, Rebecca Sue; Jorgenson, Roy Eberhardt; Hjalmarson, Harold Paul; Pasik, Michael Francis

2013-09-01T23:59:59.000Z

375

Monolithic high voltage nonlinear transmission line fabrication process  

DOE Patents (OSTI)

A process for fabricating sequential inductors and varistor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varistor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process. 6 figs.

Cooper, G.A.

1994-10-04T23:59:59.000Z

376

Monolithic high voltage nonlinear transmission line fabrication process  

DOE Patents (OSTI)

A process for fabricating sequential inductors and varactor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varactor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process.

Cooper, Gregory A. (346 Primrose Dr., Pleasant Hill, CA 94523)

1994-01-01T23:59:59.000Z

377

Voltage spike detection in high field superconducting accelerator magnets  

SciTech Connect

A measurement system for the detection of small magnetic flux changes in superconducting magnets, which are due to either mechanical motion of the conductor or flux jump, has been developed at Fermilab. These flux changes are detected as small amplitude, short duration voltage spikes, which are {approx}15mV in magnitude and lasts for {approx}30 {micro}sec. The detection system combines an analog circuit for the signal conditioning of two coil segments and a fast data acquisition system for digitizing the results, performing threshold detection, and storing the resultant data. The design of the spike detection system along with the modeling results and noise analysis will be presented. Data from tests of high field Nb{sub 3}Sn magnets at currents up to {approx}20KA will also be shown.

Orris, D.F.; Carcagno, R.; Feher, S.; Makulski, A.; Pischalnikov, Y.M.; /Fermilab

2004-12-01T23:59:59.000Z

378

Voltage holding considerations for direct-collection units  

SciTech Connect

Results have been obtained from initial experiments designed to study high-voltage breakdown under conditions of importance to the design of direct- collection units. A coaxial configuration was used to mock-up critical fields near grid wires. With appropriate heat conditioning, fields as high as 9.6 x 10/ sup 5/ V/cm were maintained at the surface of a 7-mil-diam tungsten wire. This represents an enhanced field of ~10/sup 8/V/cm at whisker'' sites. Breakdown criteria are proposed for three regimes; initial, field-emission, and ultimate, which differ by the amount of prior conditioning applied to the wire. Additional considerations of importance to direct collectors such as the effect of thermionic emission and ion bombardment are discussed. (auth)

Miley, G.H.

1973-12-01T23:59:59.000Z

379

High voltage design structure for high temperature superconducting device  

DOE Patents (OSTI)

In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.

Tekletsadik, Kasegn D. (Rexford, NY)

2008-05-20T23:59:59.000Z

380

Curing system for high voltage cross linked cables  

DOE Patents (OSTI)

This invention makes extruded, vulcanized, high voltage cables insulated with thermosetting compounds at much higher rates of production and with superior insulation of reduced thickness and with reduced cavities or voids in the insulation. As the cable comes from an extruder, it passes into a curing chamber with a heat booster that quickly raises the insulation to a temperature at which it is cured much more quickly than with steam heating of the prior art. A high temperature liquid in contact with the insulation maintains the high temperature; and because of the greater curing heat, the cable can travel through the curing chamber at a faster rate and into a cooling tube where it contacts with a cooling liquid under high pressure. The insulation compound is treated to reduce the size of cavities; and the high pressure maintained by the curing and cooling mediums prevent expansion of cavities before the insulation is set.

Bahder, George (Edison, NJ); Katz, Carlos (Edison, NJ); Bopp, Louis A. (Fair Haven, NJ)

1978-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Sacramento Area Voltage Support Draft Environmental Impact Statement  

Science Conference Proceedings (OSTI)

The Western Area Power Administration's Central Valley Project transmission system forms an integral part of the interconnected Sacramento area transmission grid. Western is contractually responsible to oversee that the system is operated in accordance with strict reliability standards. Growth in the greater Sacramento, California area and power imported from generation outside the region, have increased the demand on the interconnected electric transmission system, leading to transmission system overloads and reducing the reliability and security of the area power system. Western has prepared this Sacramento Area Voltage Support (SVS) Draft Environmental Impact Statement (EIS) in compliance with Federal laws, regulations and guidelines, principally the ''National Environmental Policy Act'' (NEPA). This Draft EIS evaluates the potential environmental effects of physical improvements to the area's power system. Enhancements are needed to improve system reliability and provide voltage support for the Sacramento area. The results of public scoping meetings, workshops, meetings with agencies, and earlier studies by Western and area utilities helped to develop a range of alternatives for analysis. The Proposed Action involves: Constructing a new double-circuit, 230-kV transmission line paralleling the existing double-circuit, 230-kV line from the O'Banion Substation to the Elverta Substation; Realigning a portion of the existing Cottonwood-Roseville single-circuit, 230-kV transmission line north of Elverta Substation; and Reconductoring the existing double-circuit, 230-kV transmission line from the Elverta Substation to the Tracy Substation. Public Hearings on the Draft EIS will be held between December 9-12, 2002. Comments on this Draft EIS are encouraged and should be sent to Ms. Loreen McMahon (above). Comments must be received by December 30, 2002.

N /A

2002-11-15T23:59:59.000Z

382

Sacramento Area Voltage Support Final Environmental Impact Statement  

Science Conference Proceedings (OSTI)

The Western Area Power Administration's Central Valley Project transmission system forms an integral part of the interconnected Sacramento area transmission grid. Western is contractually responsible to oversee that the system is operated in accordance with strict reliability standards. Growth in the greater Sacramento, California area and power imported from generation outside the region, have increased the demand on the interconnected electric transmission system, leading to transmission system overloads and reducing the reliability and security of the area power system. Western has prepared this Sacramento Area Voltage Support (SVS) Draft Environmental Impact Statement (EIS) in compliance with Federal laws, regulations and guidelines, principally the National Environmental Policy Act (NEPA). This Draft EIS evaluates the potential environmental effects of physical improvements to the area's power system. Enhancements are needed to improve system reliability and provide voltage support for the Sacramento area. The results of public scoping meetings, workshops, meetings with agencies, and earlier studies by Western and area utilities helped to develop a range of alternatives for analysis. The Proposed Action involves: (1) Constructing a new double-circuit, 230-kV transmission line paralleling the existing double-circuit, 230-kV line from the O'Banion Substation to the Elverta Substation; (2) Realigning a portion of the existing Cottonwood-Roseville single-circuit, 230-kV transmission line north of Elverta Substation; and (3) Reconductoring the existing double-circuit, 230-kV transmission line from the Elverta Substation to the Tracy Substation. Public Hearings on the Draft EIS will be held between December 9-12, 2002. Comments on this Draft EIS are encouraged and should be sent to Ms. Loreen McMahon (above). Comments must be received by December 30, 2002.

N /A

2003-09-19T23:59:59.000Z

383

DECENTRALIZED CONTROL ARCHITECTURE FOR COUPLING MICROGRIDS INTO DISTRIBUTION NETWORKS 1 Task 1: Coupling Low-Voltage Microgrids into  

E-Print Network (OSTI)

DECENTRALIZED CONTROL ARCHITECTURE FOR COUPLING MICROGRIDS INTO DISTRIBUTION NETWORKS 1 Task 1: Coupling Low-Voltage Microgrids into Mid-Voltage Distribution Systems Zhao Wang, Student Member, IEEE-voltage (LV) microgrids. At the same time, reactive power is dispatched coordinatively so that voltage

Lemmon, Michael

384

Pulsed voltage electrospray ion source and method for preventing analyte electrolysis  

SciTech Connect

An electrospray ion source and method of operation includes the application of pulsed voltage to prevent electrolysis of analytes with a low electrochemical potential. The electrospray ion source can include an emitter, a counter electrode, and a power supply. The emitter can include a liquid conduit, a primary working electrode having a liquid contacting surface, and a spray tip, where the liquid conduit and the working electrode are in liquid communication. The counter electrode can be proximate to, but separated from, the spray tip. The power system can supply voltage to the working electrode in the form of a pulse wave, where the pulse wave oscillates between at least an energized voltage and a relaxation voltage. The relaxation duration of the relaxation voltage can range from 1 millisecond to 35 milliseconds. The pulse duration of the energized voltage can be less than 1 millisecond and the frequency of the pulse wave can range from 30 to 800 Hz.

Kertesz, Vilmos (Knoxville, TN); Van Berkel, Gary (Clinton, TN)

2011-12-27T23:59:59.000Z

385

Turbine-Generator Topics for Power Plant Engineers: Synchronous Generator Voltage Regulator Basics  

Science Conference Proceedings (OSTI)

This material is intended for the new engineer, the control room operator, management, or the non-engineer. The basics of a synchronous generator excitation system; the fundamentals of the voltage regulator; and its controls and functions are discussed. The typical exciter types are covered, but not in detail. There is also basic information on voltage regulator maintenance issues. Put simply, the excitation system is made up of three basic component systems. The voltage regulator monitors the synchronou...

2012-02-16T23:59:59.000Z

386

Assessment and Evaluation of Next Generation High-Voltage DC Technologies—Phase 2  

Science Conference Proceedings (OSTI)

As an established technology for bulk power transmission, high-voltage direct current (HVDC) power transmission is being used worldwide, and more than 100 schemes are operating at present. Advances in voltage sourced converter (VSC) technologies and power electronic devices with use of insulated-gate bipolar transistors (IGBTs) will provide improved system performance and reliability. Also, the present highest operating voltage is +/- 800 kV as China and India are building +/- 800-kV lines. Anticipating ...

2009-12-17T23:59:59.000Z

387

Technology Assessment and Application Guide for a Capacitor-Based Voltage Sag Compensator  

Science Conference Proceedings (OSTI)

Voltage sags and momentary interruptions result in a significant amount of process shutdowns for industrial customers. Voltage sag compensation devices help mitigate sags for susceptible devices and components, allowing for more reliable and robust process performance. This report provides a technology assessment and application guide for Marathon Power's Voltage Sag Compensator, a 120-V, 750-VA unit designed to provide AC backup power to sensitive electronic loads.

2009-12-22T23:59:59.000Z

388

ETTM: Low Voltage System Protection and Coordination Computer-Based Training Version 1.0  

Science Conference Proceedings (OSTI)

ETTM Low Voltage System Protection and Coordination is a computer-based training module that allows users to access training when desired and review it at their own pace. It provides graphics and limited interactive features to enhance learning. Low voltage power systems are generally classified as AC power systems operating at the 120 600 Volt level. Because they often serve a large number of diverse loads in residences, businesses, and power plants, low voltage power systems present a unique set of cha...

2010-11-30T23:59:59.000Z

389

Unlikely Combination of Experiments with a Novel High-Voltage CIGS Photovoltaic Array (Presentation)  

DOE Green Energy (OSTI)

The goals of this study are to: (1) parameterize current-voltage (I-V) performance over a wide range of illumination and temperatures: (a) 50-1150 W/m{sup 2} irradiance, 5-65 C; (b) obtain array temperature coefficients; and (c) quantify energy production; (2) investigate high-voltage leakage currents from the CIS modules in a high-voltage array: determine dependence on moisture, temperature, and voltage bias and ascertain corrosion problems if any; and (3) study long-term power and energy production stability.

del Cueto, J. A.; Sekulic, B. R.

2006-05-01T23:59:59.000Z

390

Phase-Field Simulations of a Simple Voltage-Controlled Magnetic ...  

Science Conference Proceedings (OSTI)

The voltage-induced magnetization and/or magnetic domain switching dynamics in ... Our results offer a promising new way towards future high-performance ...

391

Effect of Voltage Pulse Duration on Surface Properties of Micro Arc ...  

Science Conference Proceedings (OSTI)

Durations of successive positive and negative voltage pulses in one cycle ... Electrodeposition of Ni-Al-Cr Bond Coat and Its High Temperature Behavior on ...

392

High voltage bus and auxiliary heater control system for an electric or hybrid vehicle  

DOE Green Energy (OSTI)

A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

Murty, Balarama Vempaty (West Bloomfield, MI)

2000-01-01T23:59:59.000Z

393

Theory and practice of dynamic voltage/frequency scaling in the high performance computing environment.  

E-Print Network (OSTI)

?? This dissertation provides a comprehensive overview of the theory and practice of Dynamic Voltage/Frequency Scaling (DVFS) in the High Performance Computing (HPC) environment. We… (more)

Rountree, Barry Louis

2010-01-01T23:59:59.000Z

394

Theory and Practice of Dynamic Voltage/Frequency Scaling in the High Performance Computing Environment .  

E-Print Network (OSTI)

??This dissertation provides a comprehensive overview of the theory and practice of Dynamic Voltage/Frequency Scaling (DVFS) in the High Performance Computing (HPC) environment. We summarize… (more)

Rountree, Barry

2009-01-01T23:59:59.000Z

395

Summary of transient high-voltage calculations for the FRX-C experiment  

Science Conference Proceedings (OSTI)

Calculations of the electrical circuit equations are performed over a wide range of parameters corresponding to the FRX-C field-reversed THETA-pinch experiment at Los Alamos. Without any plasma or external damping, serious voltage doubling and quadrupling of the main capacitor bank charge voltage are observed. These oscillating high voltages are found to be adequately suppressed by the strategic placement of external snubber circuitry. On the other hand, no doubling of the THETA-pinch preionization bank charge voltage is found. Calculations of the equations for the z-pinch preionization circuit are also performed.

Kewish, R.W. Jr.; Rej, D.J.

1982-06-01T23:59:59.000Z

396

The dynamics of electricity demand and supply in the low voltage distribution grid: a model study:.  

E-Print Network (OSTI)

??In this thesis a simulation study is executed that analyses how new developments of household electricity demand and decentralised electricity generation affect the low voltage… (more)

Van Zoest, P.L.A.

2013-01-01T23:59:59.000Z

397

Radio-Frequency Interference (RFI) From Extra-High- Voltage (EHV) Transmission Lines  

E-Print Network (OSTI)

The subject of radio-frequency interference (RFI) generated by high-voltage transmission lines has long been of both academic and commercial interest because of concerns about

Patrick C. Crane

2010-01-01T23:59:59.000Z

398

Measurement-based Voltage Stability Margin Calculator (MVSMC) v1.0  

Science Conference Proceedings (OSTI)

Voltage stability is a major concern in daily power system operations and a leading factor to limit power transfers in a prevailing open access environment. Voltage instability usually starts from a local bus or area, and then may evolve into a wide-area instability problem if it cannot be controlled locally. This program utilizes EPRImeasurement-based voltage stability monitoring technology and is able to calculate voltage stability margin indices at a load bus or for an entire load area using the measu...

2009-10-30T23:59:59.000Z

399

Triple-Voltage DC-DC Converter - Oak Ridge National Laboratory  

Overall Project Objective ... –Saving in the switch and gate drive component count increases ... power transfer between the low-voltage buses and the high

400

Development of an assessment methodology for geopressured zones of the upper Gulf Coast based on a study of abnormally pressured gas fields in South Texas. Progress report, 1 March 1976--31 May 1976  

DOE Green Energy (OSTI)

During the fourth quarterly reporting period project change-in-scope was approved extending the study area to include Brooks, the remainder of Kenedy and Live Oak Counties. An interim progress report covering that reporting period is presented. Effort during the quarter was directed toward (1) locating drillstem and production test results from geopressured formations, (2) determining formation parameters in an additional large number of producing wells, and (3) searching production records for assessment of geopressured production in Brooks and Kenedy Counties. Several unsuccessful completion tests of geopressured water sands (attempted as gas completions) have been located and these give insight into the problems of completing high-volume water wells in that zone. A successful fracture treatment in a geopressured gas well indicates a producibility increase equivalent to a two-fold improvement in permeability. Permeability calculations for a large number of geopressured and normally pressured gas wells throughout the study area have been completed. In no case has a producing Rio Grande Valley gas well deeper than 10,000 ft. been identified with effective permeability as great as 10 md. Preliminary investigation of Brooks County production has located geopressured production in seven gas fields and in North Kenedy County, an additional three.

Swanson, R.K.; Oetking, P.; Osoba, J.S.; Hagens, R.C.

1976-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

High voltage power supply with modular series resonant inverters  

DOE Patents (OSTI)

A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360.degree./n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit.

Dreifuerst, Gary R. (Livermore, CA); Merritt, Bernard T. (Livermore, CA)

1995-01-01T23:59:59.000Z

402

High voltage power supply with modular series resonant inverters  

DOE Patents (OSTI)

A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360{degree}/n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit. 11 figs.

Dreifuerst, G.R.; Merritt, B.T.

1995-07-18T23:59:59.000Z

403

Life testing of a low voltage air circuit breaker  

Science Conference Proceedings (OSTI)

A DS-416 low voltage air circuit breaker manufactured by Westinghouse was mechanically cycled to identify age-related degradation in the various breaker subcomponents, specifically the power-operated mechanism. This accelerated aging test was performed on one breaker unit for over 36,000 cycles. Three separate pole shafts, one with a 60-degree weld, one with a 120-degree weld, and one with a 180-degree weld in the third pole lever were used to characterize cracking in the welds. In addition, during the testing three different operating mechanisms and several other parts were replaced as they became inoperable. Among the seven welds on the pole shaft, {number_sign}1 and {number_sign}3 were found to be critical ones whose fracture can result in misalignment of the pole levers. This can lead to problems with the operating mechanism, including the burning of coils, excessive wear in certain parts, and overstressed linkages. Furthermore, the limiting service life of a number of subcomponents of the power-operated mechanism, including the operating mechanism itself, were assessed. Based on these findings, suggestions are provided to alleviate the age-related degradation that could occur as a result of normal closing and opening of the breaker contacts during its service life. Also, cause and effect analyses of various age-related degradation in various breaker parts are discussed.

Subudhi, M. [Brookhaven National Lab., Upton, NY (United States); Aggarwal, S. [Nuclear Regulatory Commission, Washington, DC (United States)

1992-06-01T23:59:59.000Z

404

Life testing of a low voltage air circuit breaker  

Science Conference Proceedings (OSTI)

A DS-416 low voltage air circuit breaker manufactured by Westinghouse was mechanically cycled to identify age-related degradation in the various breaker subcomponents, specifically the power-operated mechanism. This accelerated aging test was performed on one breaker unit for over 36,000 cycles. Three separate pole shafts, one with a 60-degree weld, one with a 120-degree weld, and one with a 180-degree weld in the third pole lever were used to characterize cracking in the welds. In addition, during the testing three different operating mechanisms and several other parts were replaced as they became inoperable. Among the seven welds on the pole shaft, {number sign}1 and {number sign}3 were found to be critical ones whose fracture can result in misalignment of the pole levers. This can lead to problems with the operating mechanism, including the burning of coils, excessive wear in certain parts, and overstressed linkages. Furthermore, the limiting service life of a number of subcomponents of the power-operated mechanism, including the operating mechanism itself, were assessed. Based on these findings, suggestions are provided to alleviate the age-related degradation that could occur as a result of normal closing and opening of the breaker contacts during its service life. Also, cause and effect analyses of various age-related degradation in various breaker parts are discussed.

Subudhi, M. (Brookhaven National Lab., Upton, NY (United States)); Aggarwal, S. (Nuclear Regulatory Commission, Washington, DC (United States))

1992-01-01T23:59:59.000Z

405

Circuit for monitoring temperature of high-voltage equipment  

DOE Patents (OSTI)

This invention relates to an improved circuit for measuring temperature in a region at high electric potential and generating a read-out of the same in a region at lower potential. The circuit is specially designed to combine high sensitivity, stability, and accuracy. A major portion of the circuit situated in the high-potential region can take the form of an integrated circuit. The preferred form of the circuit includes an input section which is situated in the high-potential region and comprises a temperature-compensated thermocouple circuit for sensing temperature, an oscillator circuit for generating a train of ramp voltages whose rise time varies inversely with the thermocouple output, a comparator and switching circuit for converting the oscillator output to pulses whose frequency is proportional to the thermocouple output, and a light-emitting diode which is energized by these pulses. An optical coupling transmits the light pulses generated by the diode to an output section of the circuit, situated in a region at ground. The output section comprises means for converting the transmitted pulses to electrical pulses of corresponding frequency, means for amplifying the electrical pulses, and means for displaying the frequency of the same. The preferred embodiment of the overall circuit is designed so that the frequency of the output signal in hertz and tenths of hertz is equal to the sensed temperature in degrees and tenths of degrees.

Jacobs, Martin E. (Chillicothe, OH)

1976-01-01T23:59:59.000Z

406

PRESENT AND FUTURE TECHNOLOGY OF HIGH VOLTAGE SYSTEMS FOR NEUTRAL BEAM INJECTORS  

E-Print Network (OSTI)

the accel voltage reg­ ulation requirement could be relaxedVOLTAGE SWITCHES TUBES SCR ASSEMBLIES CROSSED-FIELD INTERRUPTERS MAGNETIC CORE ARC SNUEBER3 COMPUTERS FOR CONTROL AND DIAGNOSTICS OPERATIONAL REQUIREMENTSvoltage- regulated (flat-topped) to 1%. If good regulation Is not a prime requirement,

Baker, W.R.

2011-01-01T23:59:59.000Z

407

Voltage-tunable singlet-triplet transition in lateral quantum dots  

E-Print Network (OSTI)

Results of calculations and high source-drain transport measurements are presented which demonstrate voltage-tunable entanglement of electron pairs in lateral quantum dots. At a fixed magnetic field, the application of a judiciously-chosen gate voltage alters the ground-state of an electron pair from an entagled spin singlet to a spin triplet.

Jordan Kyriakidis; M. Pioro-Ladriere; M. Ciorga; A. S. Sachrajda; P. Hawrylak

2001-11-28T23:59:59.000Z

408

Simulation for Performance Analysis of Grid-Connected Induction Generators with Input Voltage Control  

Science Conference Proceedings (OSTI)

With the increasing application of wind energy, various technologies are developed for analyzing the performance of grid-connected induction generator (GIG) based wind energy conversion systems (WECSs). Input voltage control is one among them. In the ... Keywords: grid-connected induction generators (GIGs), wind energy conversion systems (WECSs), input voltage control, performance analysis, MATLAB

Farhad Ilahi Bakhsh, Shirazul Islam, Sayeed Ahmad

2013-04-01T23:59:59.000Z

409

Modeling considerations in static and dynamic voltage stability studies of shipboard power systems  

Science Conference Proceedings (OSTI)

Better modeling is a key issue to system analysis and emulating real system performances accurately. This paper addresses modeling considerations and approaches to be taken for voltage stability analysis. Two approaches, static and dynamic analysis, ... Keywords: PSCAD, dynamic analysis, numerical integration method, static analysis, voltage stability

Minglan Lin; Anurag K. Srivastava; Noel N. Schulz

2007-07-01T23:59:59.000Z

410

A New Thermal-Conscious System-Level Methodology for Energy-Efficient Processor Voltage Selection  

E-Print Network (OSTI)

A New Thermal-Conscious System-Level Methodology for Energy-Efficient Processor Voltage Selection a thermal-conscious system-level methodology to make energy-efficient voltage selection (VS) for nanometer), thermal resistance, are integrated and considered in our system models, and their impacts on energy

Wang, Yu

411

Energy-efficient datapath scheduling using multiple voltages and dynamic clocking  

Science Conference Proceedings (OSTI)

Recently, dynamic frequency scaling has been explored at the CPU and system levels for power optimization. Low-power datapath scheduling using multiple supply voltages has been well researched. In this work, we develop new datapath scheduling algorithms ... Keywords: High-level synthesis, dynamic frequency clocking, low-power datapath synthesis, multiple voltage scheduling, resource-constrained scheduling, time-constrained scheduling

Saraju P. Mohanty; N. Ranganathan

2005-04-01T23:59:59.000Z

412

Analysis and Mitigation of Balanced Voltage Sag with the Help of Energy Storage System  

Science Conference Proceedings (OSTI)

Voltage sag is one of the major power quality problem which results in a failure or a mis-operation of end use equipments. Sensitive industrial loads and Utility distribution networks all suffer from various types of outages and service interruptions ... Keywords: Power quality, voltage sag, Custom power Devices, DVR, Energy Storage System, pulse width modulation

D. N. Katole; K. D. Joshi

2010-11-01T23:59:59.000Z

413

Steady-state power flow modeling for a dynamic voltage restorer  

Science Conference Proceedings (OSTI)

This paper presents analysis, modeling and simulation of power distribution network performance incorporating with an installed dynamic voltage restorer (DVR). DVR is one of series compensators used in power distribution systems in order to maintain ... Keywords: Gauss-Seidel method, dynamic voltage restorer, modeling, power flow, simulation

T. Ratniyomchai; T. Kulworawanichpong

2006-03-01T23:59:59.000Z

414

Extraction of voltage harmonics using multi-layer perceptron neural network  

Science Conference Proceedings (OSTI)

This paper presents a harmonic extraction algorithm using artificial neural networks for Dynamic Voltage Restorers (DVRs). The suggested algorithm employs a feed forward Multi Layer Perceptron (MLP) Neural Network with error back propagation learning ... Keywords: Dynamic Voltage Restorer, Harmonic extraction, Multi Layer Perceptron, Neural Networks

Mehmet Tümay; M. Emin Meral; K. Ça?atay Bayindir

2008-09-01T23:59:59.000Z

415

Analysis of Low Voltage Ride through Capability in Wind Turbine Based on DFIG  

Science Conference Proceedings (OSTI)

In this paper the coordination of the low voltage ride through capability and the crowbar protection of DFIG are discussed. Different protection strategies for over-current and low voltage protection are presented. Effect of different short-circuit impedance, ... Keywords: doubly fed induction generator (DFIG), low voltges ride through (LVRT), crowbar protection

Shan-Ying Li; Yu Sun; Tao Wu; Yu-Zhi Liang; Xiao Yu; Jian-Ming Zhang

2010-06-01T23:59:59.000Z

416

The Influence of Electrical Parameters of Double Fed Induction Generator on the Transient Voltage Stability  

Science Conference Proceedings (OSTI)

This paper describes the effect of electrical parameters of the double fed induction generator on the transient voltage stability of a DFIG to a simple grid; the DFIG model has been developed in the Matlab/simulink tool. The dynamic behavior of a wind ... Keywords: DFIG model, electrical parameter, voltage stability, small signal analysis

Hongmei Li; Qiulan Wan; Zhaoxing Ma

2010-06-01T23:59:59.000Z

417

Research on the Control Strategy of Low Voltage Ride-Through for Doubly Fed Induction Generator  

Science Conference Proceedings (OSTI)

With the development of modern wind energy generation, higher requirements to the grid in case of a failure were raised. In order to faciliate the recovery of power, while voltage dips in a certain range, protecting the rotor side converter and providing ... Keywords: Wind energy generation, Doubly fed generator, Voltage sag, Dynamic response analysis

Zhang Jianhua; Wang Jian; Mo Yueping; Xin Fulong

2011-02-01T23:59:59.000Z

418

Study on Control Strategy for DFIG-Based Wind Turbines Under Unbalanced Grid Voltages  

Science Conference Proceedings (OSTI)

Unbalanced input voltages would make doubly fed induction generator (DFIG)-based wind turbine operating performance deteriorate, such as shaft tremble, temperature increasing, and so on, even make it cut out of the power grid. Meanwhile, without proper ... Keywords: DFIG, dual current control, unbalanced input voltages

Changxi Huang, Shuying Yang, Xing Zhang, Zhen Xie

2012-07-01T23:59:59.000Z

419

Study on the operation of a low-voltage AC microgrid with multiple distributed generations  

Science Conference Proceedings (OSTI)

This paper aims to study the operation of a grid-connected low-voltage AC microgrid with multiple distributed generations (DGs). First of all, a 400 V low-voltage AC microgrid integrated with a 30 kW microturbine generator, a 13 kW photovoltaic generation ... Keywords: distributed generators, distribution systems, microgrids, steady-state analysis, three-phase power flow

Wei-Tzer Huang

2010-12-01T23:59:59.000Z

420

Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting  

E-Print Network (OSTI)

Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting}@binghamton.edu Abstract In this paper, an energy aware dynamic voltage and frequency selection (EA-DVFS) algorithm energy and the harvested energy in a future duration. Specifically, if the system has sufficient energy

Qiu, Qinru

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Current status of CMOS low voltage and low power wireless IC designs  

Science Conference Proceedings (OSTI)

This paper surveys recent research on CMOS low voltage and low power IC designs for wireless applications. Advancements and challenges in using nanometer IC processes are addressed, and the impacts of device scaling on wireless systems are discussed. ... Keywords: CMOS, Integrated Circuits (IC), Low-Power, Low-Voltage, Nanometer, Radio Frequency (RF), Sub-1V, Wireless

Tommy K. Tsang; Mourad N. El-Gamal; Krzysztof Iniewski; Kenneth A. Townsend; James W. Haslett; Yanjie Wang

2007-10-01T23:59:59.000Z

422

Chiller Shutdowns Caused by Sensitivity of Control Relays to Voltage Sags  

Science Conference Proceedings (OSTI)

This document presents the investigation performed by the EPRI Power Electronics Applications Center (PEAC) and Potomac Electric Power Company (PEPCO) of chiller shutdowns which coincided with momentary reduced voltage or voltage sags at the National Archives II, a U.S. government research and storage facility that houses many of our national treasures.

2003-12-31T23:59:59.000Z

423

Investigating the electric power distribution system (EPDS) bus voltage in the presence of distributed generation (DG)  

Science Conference Proceedings (OSTI)

This paper investigates the Electric Power Distribution System (EPDS) bus voltage in the presence of Distributed Generation (DG). Distribution Company's (Discos) planner endeavor to develop new planning strategies for their network in order to serve ... Keywords: PSCAD, distributed generation, electric power distribution system, islanding, power quality, voltage stability

Hasham Khan; Mohammad Ahmad Choudhry; Tahir Mahmood; Aamir Hanif

2006-04-01T23:59:59.000Z

424

FPGA Implementation of Space Vector PWM Technique for Voltage Source Inverter Fed Induction Motor Drive  

Science Conference Proceedings (OSTI)

This paper presents implementation of Space Vector Pulse Width Modulation (SVPWM) technique for three phase Voltage Source Inverter (VSI) using Field Programmable Gate Array (FPGA). Variable voltage and frequency supply to ac drives is invariably obtained ... Keywords: VSI, SVPWM, FPGA, Induction Motor

R. Rajendran; N. Devarajan

2009-12-01T23:59:59.000Z

425

A Smart Grid Voltage Sag Detector using an EEMD-Based Approach  

E-Print Network (OSTI)

A Smart Grid Voltage Sag Detector using an EEMD-Based Approach Yassine Amirat, Member, IEEE and Mohamed Benbouzid, Senior Member, IEEE Abstract--Smart grids have become a focal point in renewable energy detection in smart grids. Index Terms--Smart grid, voltage sag detection, power quality (PQ), ensemble

Brest, Université de

426

High-Voltage Broadband-Over-Powerline (HV-BPL) Field Test Report | Open  

Open Energy Info (EERE)

High-Voltage Broadband-Over-Powerline (HV-BPL) Field Test Report High-Voltage Broadband-Over-Powerline (HV-BPL) Field Test Report Jump to: navigation, search Tool Summary LAUNCH TOOL Name: High-Voltage Broadband-Over-Powerline (HV-BPL) Field Test Report Focus Area: Crosscutting Topics: Policy Impacts Website: www.netl.doe.gov/smartgrid/referenceshelf/reports/HV-BPL_Final_Report. Equivalent URI: cleanenergysolutions.org/content/high-voltage-broadband-over-powerline Language: English Policies: "Deployment Programs,Financial Incentives" is not in the list of possible values (Deployment Programs, Financial Incentives, Regulations) for this property. DeploymentPrograms: Technical Assistance This reports details findings from a pilot High Voltage Broadband over Power Line (HV-BPL) program, an effort to develop a disruptive technology

427

Capabilities of the High Voltage Stress Test System at the Outdoor Test Facility  

DOE Green Energy (OSTI)

We illustrate the capabilities of the High Voltage Stress Test (HVST) which operates continuously in the array field east of the Outdoor Test Facility at the National Renewable Energy Laboratory. Because we know that photovoltaic (PV) modules generating electrical power in both residential and utility-scale array installations will develop high-voltage biases approaching 600 VDC and 1,000 VDC, respectively, we expect such high voltages will result in current leakage between cells and ground, typically through the frames or mounts. We know that inevitably such leakage currents are capable of producing electrochemical corrosion that adversely impacts long-term module performance. With the HVST, we stress or operate PV modules under high-voltage bias, to characterize their leakage currents under all prevailing ambient conditions and assess performance changes emanating from high-voltage stress. We perform this test both on single modules and an active array.

del Cueto, J. A.; Trudell, D.; Sekulic, W.

2005-11-01T23:59:59.000Z

428

Voltage protection scheme for MG sets used to drive inductive energy storage systems  

DOE Green Energy (OSTI)

A recent tokamak proposal at ORNL called for MG (motor-generator) sets to drive the ohmic heating (OH) coil, which was to be subjected to 20 kV immediately after coil charge-up to initiate the experiment. Since most rotating machinery is inherently low voltage, including the machines available at ORNL, a mechanism was necessary to isolate the generators from the high voltage portions of the circuit before the appearance of this voltage. It is not the expected 20 kV at the coil that causes difficulty, because the main interrupting switch handles this. The voltage induced in the armature due to di/dt and the possibility of faults are the greatest causes for concern and are responsible for the complexity of the voltage protection scheme, which must accommodate any possible combination of fault time and location. Such a protection scheme is presented in this paper.

Campen, G.L.; Easter, R.B.

1977-01-01T23:59:59.000Z

429

Current-Voltage Characteristics of Bi-dithiolbenzene in Parallel Arrangement  

Science Conference Proceedings (OSTI)

The low voltage conductance of interacting two 1,4-dithiolbenzene (DTB) molecules is investigated. The simulation results show that the electron transport can be controlled either by changing the Fermi level position E{sub f} or modifying its inter-molecular spacing d. Molecular assembly system with close interaction between DTB units, affects significantly the conductance. In addition, the position of the Fermi plays an important role in determining the current flow. Moreover, it is important to note that E{sub f} affects not only the threshold voltage V{sub th}, but also the saturation voltage V{sub sat}. When E{sub f} approaches the LUMO energy level, V{sub th} decreases, while V{sub sat} increases. To conclude, the threshold voltage and the saturation voltage depend on the Fermi level position and the inter-molecular spacing.

Boudjella, Aissa [Department of Computer and Communication Technolgy, Faculty of Information and communication, Technology, University Tunku Abdul Rahman, Jalan University, Bandar Barat, 31900 Kampar, Perak (Malaysia)

2011-03-30T23:59:59.000Z

430

High voltage bus and auxiliary heater control system for an electric or hybrid vehicle  

DOE Patents (OSTI)

A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

Murty, Balarama Vempaty (West Bloomfield, MI)

2000-01-01T23:59:59.000Z

431

An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.  

SciTech Connect

References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

Litzenberger, Wayne; Lava, Val

1994-08-01T23:59:59.000Z

432

High Power, High Voltage FETs in Linear Applications: A User's Perspective  

SciTech Connect

The specifications of the current crop of highpower, high-voltage field-effect transistors (FETs) can lure a designer into employing them in high-voltage DC equipment. Devices with extremely low on-resistance and very high power ratings are available from several manufacturers. However, our experience shows that high-voltage, linear operation of these devices at near-continuous duty can present difficult reliability challenges at stress levels well-below their published specifications. This paper chronicles the design evolution of a 600 volt, 8 ampere shunt regulator for use with megawatt-class radio transmitters, and presents a final design that has met its reliability criteria.

N. Greenough, E. Fredd, S. DePasquale

2009-09-21T23:59:59.000Z

433

High-voltage crowbar circuit with cascade-triggered series ignitrons  

DOE Patents (OSTI)

A series string of ignitrons for switching a large current at high voltage to ground. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors.

Baker, William R. (Orinda, CA)

1980-01-01T23:59:59.000Z

434

High-voltage crowbar circuit with cascade-triggered series ignitrons  

DOE Patents (OSTI)

A series string of ignitrons for switching a large current at high voltage to ground. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors. 1 fig.

Baker, W.R.

1980-11-04T23:59:59.000Z

435

Operational Results of Pulse Shaping Techniques for the High Voltage Convertor Modulator  

Science Conference Proceedings (OSTI)

The High Voltage Converter Modulators (HVCMs) are used to power the RF klystrons used throughout the accelerator systems at Spallation Neutron Source (SNS). The output voltage of the HVCM has significant droop and ripple which, combined with low level RF (LLRF) system limitations, affect performance and efficiency of accelerator cavities. In conjunction with the progress in development of the new HVCM controller, different pulse modulation techniques were implemented and studied on the test modulator. This paper discusses the results of implementation of frequency modulation and phase modulation on output voltage. Operational data, including full average power operation, of test modulator is also discussed. Future plans for the new modulation scheme will be presented.

Patel, Gunjan P [ORNL; Anderson, David E [ORNL; Solley, Dennis J [ORNL; Wezensky, Mark W [ORNL

2012-01-01T23:59:59.000Z

436

A method for reducing harmonics in output voltages of a double-connected inverter  

SciTech Connect

A new method for reducing harmonics involved in output voltages of the double-connected inverter is proposed. By adding four auxiliary switching devices and an interphase transformer with secondary winding to the conventional 12-step inverter, output voltages of the proposed circuit can be almost the same waveforms as a conventional 36-step inverter. In this paper, circuit performances and output voltage waveforms are discussed, and the optimum parameters are derived. Then, effects on harmonic reductions can be clarified by theoretical and experimental results, and ratings of system components are investigated.

Masukawa, Shigeo; Iida, Shoji (Tokyo Denki Univ., Tokyo (Japan). Dept. of Electrical Engineering)

1994-09-01T23:59:59.000Z

437

Source of Sustained Voltage Difference between the Xylem of a Potted Ficus benjamina Tree and Its Soil  

E-Print Network (OSTI)

It has long been known that there is a sustained electrical potential (voltage) difference between the xylem of many plants

Mershin, Andreas

438

3430 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 61, NO. 8, OCTOBER 2012 Experimental Validation of High-Voltage-Ratio  

E-Print Network (OSTI)

Validation of High-Voltage-Ratio Low-Input-Current-Ripple Converters for Hybrid Fuel Cell Supercapacitor

Simões, Marcelo Godoy

439

A novel control strategy for dynamic voltage restorer using decoupled multiple reference frame PLL (DMRF-PLL)  

Science Conference Proceedings (OSTI)

This paper presents a new control scheme for dynamic voltage restorer (DVR), which consists of a set of series and shunt converters connected back-to-back (BTB), three series transformers, and a dc capacitor installed on the common dc-link. The DVR is ... Keywords: dc capacitor control, decoupled multiple reference frame phase locked loop (DMRF-PLL), dynamic voltage restorer, harmonic and unbalanced voltage compensation, series converters, shunt converters, voltage sag detection

Lin Xu; Yang Han; M. M. Khan; Lidan Zhou; Gang Yao; Chen Chen; Jumin Pan

2009-02-01T23:59:59.000Z

440

Integrated Technology for Distribution Systems Applications: Survey and Testing of Voltage Detecting/Indicating Devices for AC Power Lines  

Science Conference Proceedings (OSTI)

This report summarizes product reviews and testing commercially available voltage-sensing devices used to detect energized electric distribution lines, with particular focus on minimum detection and indication performance. To adequately detect line energization across the entire spectrum of possible voltage levels on a power line (from 40 Vac to full line voltage), multiple devices are currently necessary. The ideal improvement to address current gaps in voltage sensing would be the development of a ...

2013-12-17T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Application Guidelines for Motor Control Circuits Protection and Control Circuits and Devices in the Voltage Sag Environment: System Compatibility Research  

Science Conference Proceedings (OSTI)

Common electrical disturbances in the power system-such as voltage sags and brief interruptions-can disrupt the performance of electronic equipment. This project, part of EPRI's ongoing Power Quality Measurements and Testing program, focused on developing a system compatibility test protocol and conducting power quality performance testing for motor voltage controllers operating in a voltage sag environment.

2000-12-12T23:59:59.000Z

442

The progress and challenges of threshold voltage control of high-k/metal-gated devices for advanced technologies (Invited Paper)  

Science Conference Proceedings (OSTI)

This paper discusses recent progress in and challenges of threshold voltage control for advanced high-k/metal-gated (HKMG) devices. It presents the impact on threshold voltage (V"t) control of incorporating La and Al into HKMG devices. A dipole moment ... Keywords: CMOS, Capping layer, EOT, High-k, Metal gate, Threshold voltage control

Hsing-Huang Tseng; Paul Kirsch; C. S. Park; Gennadi Bersuker; Prashant Majhi; Muhammad Hussain; Raj Jammy

2009-07-01T23:59:59.000Z

443

TMS320F2812 DSP controller for dynamic voltage restorer (DVR) application for improving of a three phase inverter  

Science Conference Proceedings (OSTI)

This paper discusses a control technique improvement of a three-phase inverter using TMS320F2812 DSP controller for Dynamic Voltage Restorer (DVR) applications. The output of the inverter is then connected to a voltage grid via a second order filter ... Keywords: TMS320F2812 DSP, dynamic voltage restorer (DVR), filter, inverters, total harmonic distortion (THD)

R. Omar; N. A. Rahim

2010-07-01T23:59:59.000Z

444

Look-ahead voltage and load margin contingency selection functions for large-scale power systems  

SciTech Connect

Given the current operating condition (obtained from the real-time data), the near-term load demand at each bus (obtained from short-term load forecast), and the generation dispatch (say, based on economic dispatch), the authors present in this paper a load margin measure (MW and/or MVAR) to assess the system`s ability to withstand the forecasted load and generation variations. The authors also present a method to predict near-term system voltage profiles. The proposed look-ahead measure and the proposed voltage prediction are then applied to contingency selections for the near-term power system in terms of load margins to collapse and of the bus voltage magnitudes. They evaluate the proposed load-ahead measure and the voltage profile prediction on several power systems including a 1169-bus power system with 53 contingencies with promising results.

Chiang, H.D.; Wang, C.S.; Flueck, A.J. [Cornell Univ., Ithaca, NY (United States). School of Electrical Engineering

1997-02-01T23:59:59.000Z

445

A low-power, high-bandwidth LDO voltage regulator with no external capacitor  

E-Print Network (OSTI)

A low-dropout (LDO) voltage regulator for low-power applications is designed without an external capacitor for compensation. The regulator has two stages, the first a folded cascode amplifier and the second a large pass ...

Ha, Miranda J. (Miranda Joy)

2008-01-01T23:59:59.000Z

446

Effect of MOSFET threshold voltage variation on high-performance circuits  

E-Print Network (OSTI)

The driving force for the semiconductor industry growth has been the elegant scaling nature of CMOS technology. In future CMOS technology generations, supply and threshold voltages will have to continually scale to sustain ...

Narendra, Siva G. (Siva Gurusami), 1971-

2002-01-01T23:59:59.000Z

447

Low-voltage SEM and its Application to Steel - Programmaster.org  

Science Conference Proceedings (OSTI)

Analytical spatial resolution will be improved at low voltages. ... higher detection efficiency as well as X-ray databases for the L and M lines are required. ... Composite Sphere for Possible In Situ Microlab in Transmission Electron Microscope.

448

Voltage, Stability and Diffusion Barrier Differences between Sodium-ion and Lithium-ion Intercalation Materials  

E-Print Network (OSTI)

To evaluate the potential of Na-ion batteries, we contrast in this work the difference between Na-ion and Li-ion based intercalation chemistries in terms of three key battery properties—voltage, phase stability and diffusion ...

Ong, Shyue Ping

449

Voltage Stability Analysis of a Distributed Network Incorporating Wind Power Resource  

Science Conference Proceedings (OSTI)

This paper investigates the impacts of a wind farm connected at Harterbeespoort substation in South Africa on voltage stability of the power network. The site wind speed was determined and analyzed for viability. A comparison is made between the use ...

Denis Juma; Bessie Monchusi; Josiah Munda; Adisa Jimoh

2011-01-01T23:59:59.000Z

450

State-of-the-Art Fuel Cell Voltage Durability Status: Spring 2013 Composite Data Products  

DOE Green Energy (OSTI)

This presentation from the U.S. Department of Energy's National Renewable Energy Laboratory includes composite data products (CDPs) produced in 2013 for state-of-the-art fuel cell voltage durability status.

Kurtz, J.; Sprik, S.; Saur, G.; Peters, M.; Post, M.; Ainscough, C.

2013-05-01T23:59:59.000Z

451

The EP-4(0) shielding kits: a new approach to protection from induced voltage  

Science Conference Proceedings (OSTI)

Problems of safety in work on overhead power lines and the overhead railroad ac contact network under induced voltages are considered. The use of additional individual protection systems is proposed to provide protection from electric shock during such work.

Vorob'ev, A. Yu.; Otmorskii, S. G.; Smekalov, V. V.; Gorozhankina, E. N.; Sosunov, N. N.; Bol'shunov, A. M.

2011-09-15T23:59:59.000Z

452

A Low Power, Low Voltage, Fully Differential CMOS Variable Gain Amplifier.  

E-Print Network (OSTI)

?? This research presents a low voltage (0.8 V) fully differential CMOS variable gain amplifier. SPECTRE simulations on the designed amplifier show a -17 dB… (more)

Siddiqui, Muhammad Yousuf

2011-01-01T23:59:59.000Z

453

Design of a low-voltage low-power dc-dc HF converter  

E-Print Network (OSTI)

Many portable electronic applications could benefit from a power converter able to achieve high efficiency across wide input and output voltage ranges at a small size. However, it is difficult for many conventional power ...

Hu, Jingying, Ph. D. Massachusetts Institute of Technology.

2008-01-01T23:59:59.000Z

454

Application of multipoint DC voltage control in VSC-MTDC system  

Science Conference Proceedings (OSTI)

The voltage-source-converter- (VSC-) based multiterminal VSC-HVDC power transmission system (VSC-MTDC) is an ideal approach to connectwind farmwith power grid. Analyzing the characteristics of doubly fed induction generators aswell as the basic principle ...

Yang Xi, Ai Qian, Huang Jiantao, An Yiran

2013-01-01T23:59:59.000Z

455

Power Quality Hotline Call-of-the-Month for August 2009: Voltage Harmonics, Part 1: Fundamentals  

Science Conference Proceedings (OSTI)

This Call of the Month discusses what harmonics are and how they're produced. Part 2 will address the equipment concerns related to the presence of high levels of harmonic distortion in a customer's service voltage.

2009-12-11T23:59:59.000Z

456

Telecontrol of Ultra-High Voltage Electron Microscope over Global IPv6 Network  

Science Conference Proceedings (OSTI)

Osaka University has an Ultra-High VoltageElectron Microscope (UHVEM) which can provide highquality specimen images for worldwide researchers. Forusability improvements, we have worked on thetelecontrol of the UHVEM. In this paper, we would liketo introduce ...

Toyokazu Akiyama; Shinji Shimojo; Shojiro Nishio; Yoshinori Kitatsuji; Steven Peltier; Thomas Hutton; Fang-Pang Lin

2003-01-01T23:59:59.000Z

457

Harmonic control of multiple-stator induction machines for voltage regulation  

E-Print Network (OSTI)

Small, one to a few horsepower, three-phase induction machines with three sets of electrically-isolated, magnetically-coupled stator winding circuits are described. A voltage inverter is developed and used to drive one set ...

Holloway, Jack Wade, 1980-

2004-01-01T23:59:59.000Z

458

Trade-offs between voltage scaling and processor shutdown for low-energy embedded multiprocessors  

Science Conference Proceedings (OSTI)

When peak performance is unnecessary, Dynamic Voltage Scaling (DVS) can be used to reduce the dynamic power consumption of embedded multiprocessors. In future technologies, however, static power consumption is expected to increase significantly. Then ...

Pepijn de Langen; Ben Juurlink

2007-07-01T23:59:59.000Z

459

Fault-Delayed Voltage Recovery Control with Plug-In Hybrid Electric Vehicles  

Science Conference Proceedings (OSTI)

This paper presents an investigation into the impact that plug-in hybrid electric vehicles (PHEVs) could have to mitigate the effects of fault-delayed voltage recovery. The energy storage and conversion system in PHEVs, given potentially high levels ...

Curtis Roe; Yousef M. Al-Abdullah; Dhwanil Desai; George K. Stefopoulos; George J. Cokkinides; A. P. Meliopoulos

2010-01-01T23:59:59.000Z

460

Experimental Results from Droop Compensation for the High Voltage Converter Modulators  

Science Conference Proceedings (OSTI)

The High Voltage Convertor Modulators are used to power the RF klystrons used throughout the linear accelerator at the Spallation Neutron Source. The output voltage of the modulator has significant voltage droop and ripple which, combined with low level RF system limitations, affect performance and stability of the accelerator cavities. In conjunction with the progress in the development of the new controller, different modulation techniques were implemented and studied on the test modulator. This paper discusses experimental results from implementation of different modulation schemes has on the modulator output voltage pulse. Thermal measurements were carried out to determine the effect of these modulations schemes on long term reliability of the modulator. Future plans are also discussed.

Patel, Gunjan P [ORNL; Anderson, David E [ORNL; Peplov, Vladimir V [ORNL; Saethre, Robert B [ORNL; Solley, Dennis J [ORNL; Wezensky, Mark W [ORNL

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

A Study on Insulation Problems in Drive Fed Medium Voltage Induction Motors.  

E-Print Network (OSTI)

??The PWM (pulse-width-modulated) type voltage source converters (VSC) allow a precise speed control of induction motors with maximum achievable energy efficiency. However, the rapid growth… (more)

Haq, Saeed UL

2007-01-01T23:59:59.000Z

462

A multilevel voltage-source inverter with separate dc sources for static var generation  

SciTech Connect

A new multilevel voltage-source inverter with a separate dc sources is proposed for high-voltage, high-power applications, such as flexible ac transmission systems (FACTS) including static var generation (SVG), power line conditioning, series compensation, phase shifting, voltage balancing, fuel cell and photovoltaic utility systems interfacing, etc. The new M-level inverter consists of (M-1)/2 single phase full bridges in which each bridge has its own separate dc source. This inverter can generate almost sinusoidal waveform voltage with only one time switching per cycle as the number of levels increases. It can solve the problems of conventional transformer-based multipulse inverters and the problems of the multilevel diode-clamped inverter and the multilevel flying capacitor inverter. To demonstrate the superiority of the new inverter, a SVG system using the new inverter topology is discussed through analysis, simulation and experiment.

Peng, Fang Zheng [Tennessee Univ., Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States); Lai, Jih-Sheng; McKeever, J.; VanCoevering, J. [Oak Ridge National Lab., TN (United States)

1995-09-01T23:59:59.000Z

463

Arc voltage distribution skewness as an indicator of electrode gap during vacuum arc remelting  

DOE Patents (OSTI)

The electrode gap of a VAR is monitored by determining the skewness of a distribution of gap voltage measurements. A decrease in skewness indicates an increase in gap and may be used to control the gap.

Williamson, Rodney L. (Albuquerque, NM); Zanner, Frank J. (Sandia Park, NM); Grose, Stephen M. (Glenwood, WV)

1998-01-01T23:59:59.000Z

464

Analysis of asset health : an approach to monitoring and diagnostics for medium voltage circuit breakers  

E-Print Network (OSTI)

The Medium Voltage Electric Industry is a very conservative and risk adverse sector that has undergone very little change in the past 30 years when compared to other technologically dependent activities; this reality is ...

Corona, Erick (Erick Gustavo)

2013-01-01T23:59:59.000Z

465

Incorporating voltage security into the planning, operation and monitoring of restructured electric energy markets  

E-Print Network (OSTI)

As open access market principles are applied to power systems, significant changes are happening in their planning, operation and control. In the emerging marketplace, systems are operating under higher loading conditions as markets focus greater attention to operating costs than stability and security margins. Since operating stability is a basic requirement for any power system, there is need for newer tools to ensure stability and security margins being strictly enforced in the competitive marketplace. This dissertation investigates issues associated with incorporating voltage security into the unbundled operating environment of electricity markets. It includes addressing voltage security in the monitoring, operational and planning horizons of restructured power system. This dissertation presents a new decomposition procedure to estimate voltage security usage by transactions. The procedure follows physical law and uses an index that can be monitored knowing the state of the system. The expression derived is based on composite market coordination models that have both PoolCo and OpCo transactions, in a shared stressed transmission grid. Our procedure is able to equitably distinguish the impacts of individual transactions on voltage stability, at load buses, in a simple and fast manner. This dissertation formulates a new voltage stability constrained optimal power flow (VSCOPF) using a simple voltage security index. In modern planning, composite power system reliability analysis that encompasses both adequacy and security issues is being developed. We have illustrated the applicability of our VSCOPF into composite reliability analysis. This dissertation also delves into the various applications of voltage security index. Increasingly, FACT devices are being used in restructured markets to mitigate a variety of operational problems. Their control effects on voltage security would be demonstrated using our VSCOPF procedure. Further, this dissertation investigates the application of steady state voltage stability index to detect potential dynamic voltage collapse. Finally, this dissertation examines developments in representation, standardization, communication and exchange of power system data. Power system data is the key input to all analytical engines for system operation, monitoring and control. Data exchange and dissemination could impact voltage security evaluation and therefore needs to be critically examined.

Nair, Nirmal-Kumar

2004-12-01T23:59:59.000Z

466

Identification of Critical Voltage Control Areas (VCA) Version 3.1  

Science Conference Proceedings (OSTI)

Identify the weak sub-system and the requirement of reactive power reserves The objective of this research project is to investigate and develop a methodology for identifying areas in power systems that are prone to voltage instability under particular operating conditions and contingencies. These areas, which are prone to instability due to their lack of reactive power reserves, are referred to as voltage control areas (VCAs). Once VCAs are identified, methods of determining their adequate reactive powe...

2009-11-24T23:59:59.000Z

467

A capacitor-less low drop-out voltage regulator with fast transient response  

E-Print Network (OSTI)

Power management has had an ever increasing role in the present electronic industry. Battery powered and handheld applications require power management techniques to extend the life of the battery and consequently the operation life of the device. Most systems incorporate several voltage regulators which supply various subsystems and provide isolation among such subsystems. Low dropout (LDO) voltage regulators are generally used to supply low voltage, low noise analog circuitry. Each LDO regulator demands a large external capacitor, in the range of a few microfarads, to perform. These external capacitors occupy valuable board space, increase the IC pin count, and prohibit system-on-chip (SoC) solutions. The presented research provides a solution to the present bulky external capacitor LDO voltage regulators with a capacitor-less LDO architecture. The large external capacitor was completely removed and replaced with a reasonable 100pF internal output capacitor, allowing for greater power system integration for SoC applications. A new compensation scheme is presented that provides both a fast transient response and full range ac stability from a 0mA to 50mA load current. A 50mA, 2.8V, capacitor-less LDO voltage regulator was fabricated in a TSMC 0.35um CMOS technology, consuming only 65uA of ground current with a dropout voltage of 200mV. Experimental results show that the proposed capacitor-less LDO voltage regulator exceeds the current published works in both transient response and ac stability. The architecture is also less sensitive to process variation and loading conditions. Thus, the presented capacitor-less LDO voltage regulator is suitable for SoC solutions.

Milliken, Robert Jon

2005-12-01T23:59:59.000Z

468

Power Plant Electrical Reference Series: Guide for Rewinding and Reconditioning Medium Voltage Electric Motors: Volume 17  

Science Conference Proceedings (OSTI)

When medium-voltage motors fail, plant managers and other utility personnel have to oversee repair and rewinding. This guide provides a short-course approach to medium voltage motor repair, with sample specifications and check-off sheets to help the nonspecialist get the best service from the repair shop. The guide can also serve as a technical reference for the specialist.BackgroundThe 16 previous volumes of EPRI's Power Plant Electrical Reference Series ...

1996-09-19T23:59:59.000Z

469

Identification of Critical Voltage Control Areas and Determination of Required Reactive Power Reserves  

Science Conference Proceedings (OSTI)

The objective of this research project is to investigate and devise a methodology for identifying areas in power systems that are prone to voltage instability under particular operating conditions and contingencies. These areas, which are prone to instability due to their lack of reactive power reserves, are referred to as critical voltage control areas (VCAs). Once VCAs are identified, methods of determining their adequate reactive power reserve requirements to ensure secure system operation under all c...

2008-12-09T23:59:59.000Z

470

GaAs series connected photovoltaic converters for high voltage capacitor charging applications  

DOE Green Energy (OSTI)

This report describes the design features of series connected photovoltaic arrays which will be required to charge capacitors to relatively high (400V) voltages in time periods on the order of 1 microsecond. The factors which determine the array voltage and the capacitor charge time are given. Individual element junction designs, along with an interconnect scheme, and a semiconductor process to realize them are presented. Finally, the input laser optical required to meet the requirements is determined.

Rose, B.H.

1997-09-01T23:59:59.000Z

471

Design and characterization of a 0.35 micron CMOS voltage-to-current converter  

Science Conference Proceedings (OSTI)

This work presents the design and characterization of a CMOS voltage-to-current (V-I) converter with a current range from -100 ?A to 100 ?A. The V-I converter has a power consumption of approximately 0.6 mW and its final area was 0.022 mm2 ... Keywords: current reference, system on chip, voltage-to-current converter

Genival Mariano de Araujo; Heider Marconi G. Madureira; José Camargo da Costa

2009-08-01T23:59:59.000Z

472

Study on Reactive Power and Voltage Control of Power Grid with Small Hydropower  

Science Conference Proceedings (OSTI)

When it is in the wet season and the load is low, reactive power surplus and voltage rise are caused by high-efficiency power generation of small hydropower and load reduction in Linjiang region, Baishan city, JiLin province. These problems, which exist ... Keywords: small hydro power, vally load, reactive power balance, the rise in voltage, generator in leading power factor on operation

Yaopeng Bai; Lijie Xu; Wei Wang

2010-06-01T23:59:59.000Z

473

Touch and Step Voltage Measurements on Field Installed Ground Grid Overlaid with Gravel and Asphalt Beds  

Science Conference Proceedings (OSTI)

Gravel and asphalt are commonly used as surfacing materials in and around substations. Both the electrical characteristics of the surfacing material and its moisture condition substantially affect the exposure (step, touch) voltage and the resulting current. This project evaluates the effects of various types of surfacing materials (three gravel types and asphalt) and conditions (dry and wet) on step and touch voltages in and around substations.

2010-12-21T23:59:59.000Z

474

Normal-zone detection in tokamak superconducting magnets with Co- wound voltage sensors  

SciTech Connect

This paper discusses advantages and disadvantages of different locations of co-wound voltage sensors for quench detection in tokamak magnets with a cable-in-conduit conductor. The voltage sensor locations are analyzed and estimates of the anticipated noise vs. dB/dt are derived for transverse, parallel, and self fields. The LLNL Noise Rejection Experiment, also described here, is designed to verify theoretical expectations on a copper cable exposed to these fields that will simulate the tokamak field environment.

Martovetsky, N.N.; Chaplin, M.R.

1995-06-08T23:59:59.000Z

475

Grid Strategy 2011: Conservation Voltage Reduction and Volt VAR Optimization in the Smart Grid  

Science Conference Proceedings (OSTI)

Beginning in the 1970s with the oil embargo, utilities began looking for ways to increase the efficiency of the power distribution system, to reduce peak demand, and to conserve energy. During this period, several utilities began to test the concept of lowering the voltage to lower the demand and energy consumption on the power delivery system. As climate change and global warming became serious issues in the early 2000s, utilities began looking at Conservation Voltage Reduction (CVR) programs once again...

2011-11-11T23:59:59.000Z

476

Cermet insert high voltage holdoff improvement for ceramic/metal vacuum devices  

DOE Patents (OSTI)

An improved metal-to-ceramic seal is provided wherein the ceramic body of the seal contains an integral region of cermet material in electrical contact with the metallic member, e.g., an electrode, of the seal. The seal is useful in high voltage vacuum devices, e.g., vacuum switches, and increases the high-voltage holdoff capabilities of such devices. A method of fabricating such seals is also provided.

Ierna, W.F.

1986-03-11T23:59:59.000Z

477

Condition Monitoring and Diagnostics of Bushings, Current Transformers, and Voltage Transformers by Oil Analysis  

Science Conference Proceedings (OSTI)

This study was undertaken to determine the merits of oil analysis for condition monitoring and diagnostics of bushings, current, potential and voltage transformers. Oil test results and equipment information from 193 bushings, 830 current transformers, 194 potential transformers and 268 voltage transformers were analyzed. Statistical analyses was used to assigns equipment condition codes from 1 (Normal Operation) to 4 (Extreme) based on threshold limits for dissolved gas in oil results. A more recent set...

2006-12-12T23:59:59.000Z

478

Identification of Critical Voltage Control Areas and Determination of Required Reactive Power Reserves  

Science Conference Proceedings (OSTI)

This Technical Update reports on the development of a highly automated method for identifying Voltage Control Areas (VCAs), areas prone to voltage instability in practical power system models. For a wide range of system conditions and contingencies, the technique can identify the buses in each VCA and identify VCAs that are common for a set of contingencies and/or conditions. In addition, the method identifies the generators that are critical to maintaining stability for a given VCA. The methods develope...

2007-09-24T23:59:59.000Z

479

Engineering Technical Training Modules - Medium Voltage System Protection and Coordination Version 1.0  

Science Conference Proceedings (OSTI)

The purpose of this training module is to provide a basic understanding of protective relaying and coordination typically provided for medium voltage power systems. This module provides a discussion on current and potential transformers, the protective relays typically used as well as considerations for equipment protection and coordination or selective tripping. Medium voltage motor, transformer, and bus protection applications are covered. Lesson 4 focuses on emergency diesel generator protection in n...

2011-08-09T23:59:59.000Z

480

Technology Assessment and Application Guide for an Active Voltage Conditioner with Storage Option (AVC-Store)  

Science Conference Proceedings (OSTI)

This report describes and documents the construction, performance, and application of an active voltage conditioner (AVC) with energy storage. The system8211called the AVC-Store8211is manufactured by Vectek in Napier, New Zealand. Composed of a novel power electronics module, the system is organized to mitigate voltage sags, phase shift, and outages. This report describes the various subsystems within the AVC-Store, its operation, results of characterization tests, and issues related to its application a...

2006-06-27T23:59:59.000Z

Note: This page contains sample records for the topic "abnormal voltage abnormal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Plant Support Engineering: Aging Management Program Guidance for Medium- Voltage Cable Systems for Nuclear Power Plants  

Science Conference Proceedings (OSTI)

Regulatory and management concern regarding the reliability of medium-voltage cable systems at nuclear plants has been increasing for 5–10 years. The staff of the U.S. Nuclear Regulatory Commission (NRC) are concerned that wetted (up to and including submergence) medium-voltage cable circuits may be degrading to the point at which multiple cable circuits may fail when called on to perform functions affecting safety. Utility managers are concerned that cables may fail, causing adverse safety consequences ...

2010-06-02T23:59:59.000Z

482

FirstEnergy Uses EPRI Interregional Reactive Power Management Framework to Help Improve Transmission Voltage Stability  

Science Conference Proceedings (OSTI)

FirstEnergy teamed with EPRI and Powertech Labs to develop a practical, automated method for identifying areas prone to voltage instability due to a lack of reactive power reserves. Power system designers and operational planning engineers can use the new method to evaluate the performance of various power system designs or configurations with regard to susceptibility to voltage instability, determine weak areas requiring special remediation, and maximize the efficient use of assets by determining the mi...

2008-08-19T23:59:59.000Z

483

Radio-frequency powered glow discharge device and method with high voltage interface  

DOE Patents (OSTI)

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

1994-06-28T23:59:59.000Z

484

Radio-frequency powered glow discharge device and method with high voltage interface  

DOE Patents (OSTI)

A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

Duckworth, Douglas C. (Knoxville, TN); Marcus, R. Kenneth (Clemson, SC); Donohue, David L. (Vienna, AT); Lewis, Trousdale A. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

485

A Case Study on 2012-2013 Conservation Voltage Reduction: Ameren Illinois Smart Grid Demonstration  

Science Conference Proceedings (OSTI)

This case study presents the results of an Ameren Illinois conservation voltage reduction (CVR) test on two circuits in 2012 and 2013. Ameren Illinois is a collaborating member of the EPRI Smart Grid Demonstration Initiative, and for this project selected EPRI to support analysis for the project.The CVR project implementation included the installation of new regulator controllers with two-way radio communications, installation of voltage sensors at end-of-line locations, modifications to ...

2013-12-12T23:59:59.000Z

486

System Voltage Potential-Induced Degradation Mechanisms in PV Modules and Methods for Test: Preprint  

DOE Green Energy (OSTI)

Over the past decade, degradation and power loss have been observed in PV modules resulting from the stress exerted by system voltage bias. This is due in part to qualification tests and standards that do not adequately evaluate for the durability of modules to the long-term effects of high voltage bias experienced in fielded arrays. High voltage can lead to module degradation by multiple mechanisms. The extent of the voltage bias degradation is linked to the leakage current or coulombs passed from the silicon active layer through the encapsulant and glass to the grounded module frame, which can be experimentally determined; however, competing processes make the effect non-linear and history-dependent. Appropriate testing methods and stress levels are described that demonstrate module durability to system voltage potential-induced degradation (PID) mechanisms. This information, along with outdoor testing that is in progress, is used to estimate the acceleration factors needed to evaluate the durability of modules to system voltage stress. Na-rich precipitates are observed on the cell surface after stressing the module to induce PID in damp heat with negative bias applied to the active layer.

Hacke, P.; Terwilliger, K.; Smith, R.; Glick, S.; Pankow, J.; Kempe, M.; Kurtz, S.; Bennett, I.; Kloos, M.

2011-07-01T23:59:59.000Z

487

VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS  

E-Print Network (OSTI)

This thesis presents a thorough analysis of saddle-node bifurcations for power system dynamic models, including a third order representation of high voltage direct current (HVDC) transmission, classic ac generator dynamics with reactive flows, and voltage and frequency dependent load models. Extensions of the Point of Collapse and Continuation methods, initially used in ac system voltage stability studies, are applied to the determination of these bifurcation points. These methods are compared and used for calculating bus voltage profiles (“nose ” curves) and collapse points on ac/dc systems of up to 2158 buses, considering a variety of operational limits and controls, namely, ac/dc regulating transformer tap limits, voltage and reactive power limits, and area interchange control. AC generator reactive power limits, HVDC firing angle limits and voltage dependent current order limits (VDCOL) are shown to affect the stability and loadability of these systems. A vector Lyapunov function approach is employed to define a system wide energy function that can be used for stability analysis. This thesis describes the derivation

Claudio A. Cañizares

1991-01-01T23:59:59.000Z

488

The System Impact of Air-Conditioner Under-voltage Protection Schemes  

Science Conference Proceedings (OSTI)

This paper presents simulation results of evaluating an under-voltage protection scheme designed to take stalled air-conditioner (a/c) units offline such that the slow voltage recovery phenomena can be solved on areas heavily loaded with a/c motors during summer peak periods. A three feeder test-bed has been first used to quantify the effectiveness of the protection scheme and the sensitivity of the under-voltage relay settings. Then two real system events of the Western US power grid have been studied to evaluate the area impact of the protection scheme proposed by Southern California Edison. The study demonstrates that by taking all or most of the stalled a/c unit offline, the feeder voltage will recover in a few seconds, much quicker than the tens of seconds that the standard thermal relays imbedded in the motors need to trip the units. The drawback of the control scheme is that after the voltage recover, it settled at a higher voltage than before the faults because a large chuck of load has been shed.

Lu, Ning; Yang, Bo; Huang, Zhenyu; Bravo, Richard

2009-03-31T23:59:59.000Z

489

High Voltage Testing of a 5-meter Prototype Triaxial HTS Cable  

SciTech Connect

High voltage tests were performed on a 5-m long prototype triaxial HTS cable (supplied by Ultera) at ORNL in preparation for installation of a 200-m HTS cable of the same design at the AEP utility substation in Columbus, Ohio. The triaxial design comprises three concentric phases and shield around a common former with the phase to phase dielectric at cryogenic temperature. Advantages of this design include increased current density, a reduced amount of HTS tape needed, and reduced heat load. The phase to phase voltage will be 13.2 kVrms (7.6 kVrms to ground). Preliminary testing was done on half-scale and full-scale terminations which successfully passed AC withstand, partial discharge, and impulse tests. High voltage tests conducted on the 5-m cable with the cable straight and after bending 90 degrees were ac withstand to 39 kVrms, partial discharge inception, and a minimum of 10 positive and 10 negative lightning waveform impulses at 110 kV. Phase to phase insulation was tested by applying high voltage to each phase one at a time with all the other phases grounded. Partial discharge data will be presented. The 5-m prototype triaxial HTS cable passed all the HV tests performed, with a PD inception voltage significantly above the required voltage.

Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; Tuncer, Enis [ORNL; Pace, Marshall O [ORNL; Gouge, Michael J [ORNL; Demko, Jonathan A [ORNL; Lindsay, David T [ORNL

2007-01-01T23:59:59.000Z

490

The design, construction, and operation of long-distance high-voltage electricity transmission technologies.  

SciTech Connect

This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these conductors at a safe distance from each other and from the ground and the natural and built environment. Common elements that are generally less visible (or at least more easily overlooked) include the maintained ROW along the path of the towers, access roads needed for maintenance, and staging areas used for initial construction that may be restored after construction is complete. Also visible but less common elements along the corridor may include switching stations or substations, where lines of similar or different voltages meet to transfer power.

Molburg, J. C.; Kavicky, J. A.; Picel, K. C.

2008-03-03T23:59:59.000Z

491

Unlikely Combination of Experiments With a Novel High-Voltage CIGS Photovoltaic Array: Preprint  

DOE Green Energy (OSTI)

A new high-voltage array comprising bipolar strings of copper indium gallium diselenide (CIGS) photovoltaic (PV) modules was inaugurated in 2005. It is equipped with a unique combination of tests, which likely have never before been deployed simultaneously within a single array: full current-voltage (I-V) traces, high-voltage leakage current measurements, and peak-power tracking or temporal stepped-bias profiling. The array nominally produces 1 kW power at 1 sun. The array's electrical characteristics are continuously monitored and controlled with a programmable electronic load interfaced to a data acquisition system (DAS), that also records solar and meteorological data. The modules are mounted with their frames electrically isolated from earth ground, in order to facilitate measurement of the leakage currents that arise between the high voltage bias developed in the series-connected cells and modules and their mounting frames. Because the DAS can perform stepped biasing of the array as a function of time, synchronous detection of the leakage current data with alternating bias is available. Leakage current data and their dependence on temperature and voltage are investigated. Array power data are analyzed across a wide range of varying illuminations and temperatures from the I-V traces. Array performance is also analyzed from an energy output perspective using peak-power tracking data.

del Cueto, J. A.; Sekulic, B. R.

2006-05-01T23:59:59.000Z

492

Using Distributed Energy Resources to Supply Reactive Power for Dynamic Voltage Regulation  

Science Conference Proceedings (OSTI)

Abstract Distributed energy (DE) resources are power sources located near load centers and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide reactive power (along with active power) locally for dynamic voltage regulation. In this paper, a synchronous condenser and a DE source with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Developed voltage control schemes for the inverter and the synchronous condenser are presented. Experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously although the dynamic response of the inverter is much faster than the synchronous condenser. In a system with multiple DEs performing local voltage regulation, the interaction of multiple DE at different locations under different load levels may have an impact to the control parameter setting for each individual DE control system. Future research is needed to find out the interaction of DEs to identify the optimal control parameter settings with the consideration of many factors such as system configuration, load variation, and so on

Xu, Yan [ORNL; Li, Fangxing [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Rizy, D Tom [ORNL; Kueck, John D [ORNL

2008-01-01T23:59:59.000Z

493

Field Guide Updates for 2011: Volume 1 - Compressors for High-Voltage Circuit Breakers, Volume 2 - Lubrication of High-Voltage Circu it Breakers  

Science Conference Proceedings (OSTI)

High-voltage circuit breakers (HVCBs) perform essential protection and control functions on power transmission networks. Circuit breakers have multiple components that must operate in concert in order for the breaker to perform properly. If one component, such as the air or hydraulic system, does not operate correctly, the circuit breaker may misoperate or fail, possibly resulting in equipment damage or an outageboth expensive consequences. To help utilities prevent such undesirable events, this field gu...

2011-12-12T23:59:59.000Z

494

Fiber-optic voltage sensor with cladded fiber and evanescent wave variation detection  

DOE Patents (OSTI)

A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities.

Wood, Charles B. (Lakewood, CO)

1992-01-01T23:59:59.000Z

495

Sacramento Area Voltage Support Driaft Supplement Environmental Impact Statement and Environmental Impact Report  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Sacramento Area Voltage Support Draft SEIS/EIR * Western Area Power Administration * Sierra Nevada Region Sacramento Area Voltage Support Draft SEIS/EIR * Western Area Power Administration * Sierra Nevada Region A-1 APPEN DIX A Alternatives Development A.1 INTRODUCTION Appendix A summarizes the process used to identify and screen project alternatives for the joint, draft Supplemental Environmental Impact Statement and Environmental Impact Report (Sacramento Area Voltage Support (SVS) Draft SEIS and EIR). Public involvement was used to develop and refine alternatives. Engineering considerations were the primary factor in eliminating several alternatives. A.2 ALTERNATIVES SELECTED FOR DETAILED ANALYSIS Western Area Power Administration (Western), Sacramento Municipal Utility District (SMUD), and the City of Roseville (Roseville) identified three transmission line segments between Western's

496

A Method to Improve Voltage Holding Across Vacuum Electrical Gaps to  

NLE Websites -- All DOE Office Websites (Extended Search)

A Method to Improve Voltage Holding Across Vacuum Electrical Gaps to A Method to Improve Voltage Holding Across Vacuum Electrical Gaps to Improve the Performance and Reduce the Conditioning Time by Removing Bacteria, Fungi, and Other Microbial Organisms and Their Spores. -- . Inventor Larry Grisham. Disclosed is a method to potentially increase the performance of devices which employ electric field within a vacuum by increasing the magnitude of the electric field gradient which can be sustained, the reliability of the devices, and by reducing the conditioning time of devices such as charged particle accelerators when they are brought into operation. The disclosed method can be employed, for example, for devices requiring voltages across vacuum gaps, such as, but not limited to, charged particle accelerators, X-ray machines, vacuum tubes, and vacuum electrical breakers.

497

Performance-Aware Power Management in Embedded Controllers with Multiple-Voltage Processors  

E-Print Network (OSTI)

The goal of this work is to minimize the energy dissipation of embedded controllers without jeopardizing the quality of control (QoC). Taking advantage of the dynamic voltage scaling (DVS) technology, this paper develops a performance-aware power management scheme for embedded controllers with processors that allow multiple voltage levels. The periods of control tasks are adapted online with respect to the current QoC, thus facilitating additional energy reduction over standard DVS. To avoid the waste of CPU resources as a result of the discrete voltage levels, a resource reclaiming mechanism is employed to maximize the CPU utilization and also to improve the QoC. Simulations are conducted to evaluate the performance of the proposed scheme. Compared with the optimal standard DVS scheme, the proposed scheme is shown to be able to save remarkably more energy while maintaining comparable QoC.

Xia, Feng; Ma, Longhua; Sun, Youxian; Dong, Jinxiang

2008-01-01T23:59:59.000Z

498

A new method and instrument for touch and step voltage measurements  

SciTech Connect

This paper describes a new method and instrument for measuring touch and step voltages near a grounding system, for example in and around a substation. The hardware, software, and testing procedures are an extension of the smart ground multimeter, developed under EPRI sponsorship. The instrument injects a transient electric current between the ground under testing and an auxiliary ground, and it measures ground potential differences (GPDs) at up to six locations. The GPD measurements are processed with software which rejects external noise using correlation methods. Subsequently, statistical estimation methods are used to extract the touch or step voltages from the thousands of measurement points normalized with the system short circuit capability. Knowledge of the short circuit capability of the substation allows the quick measurements of the touch and step voltages.

Meliopoulos, A.P.S. (Georgia Inst. of Technology, Atlanta, GA (United States). School of Electrical and Computer Engineering); Patel, S. (Georgia Power Co., Atlanta, GA (United States)); Cokkinides, G.J. (Univ. of South Carolina, Columbia, SC (United States). Dept. of Electrical and Computer Engineering)

1994-10-01T23:59:59.000Z