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Sample records for ac underground cable

  1. Online Location of Faults on AC Cables in Underground Transmission Systems

    Jensen, Christian Flytkjær

    2013-01-01

    A transmission grid is normally laid out as an almost pure overhead line (OHL) network. The introduction of transmission voltage level XLPE cables and the increasing interest in the environmental impact of OHL has resulted in an increasing interest in the use of underground cables on transmission level. In Denmark for instance, the entire 150 kV, 132 kV and 220 kV and parts of the 400 kV transmission network will be placed underground before 2030.To reduce the operating losses of a cable-base...

  2. Superconducting ac cable

    The components of a superconducting 110 kV ac cable for power ratings >= 2000 MVA have been developed. The cable design especially considered was of the semiflexible type, with a rigid cryogenic envelope and flexible hollow coaxial cable cores pulled into the former. The cable core consists of spirally wound Nb-Al composite wires and a HDPE-tape wrapped electrical insulation. A 35 m long single phase test cable with full load terminations for 110 kV and 10 kA was constructed and successfully tested. The results obtained prove the technical feasibility and capability of our cable design. (orig.)

  3. Online Fault Location on AC Cables in Underground Transmission Systems using Sheath Currents

    Jensen, Christian Flytkjær; Nanayakkarab, Kasun; Rajapakse, Athula;

    2014-01-01

    This paper studies online travelling wave methods for fault location on a crossbonded cable system using sheath currents. During the construction of the electrical connection to the 400 MW off shore wind farm Anholt, it was possible to perform measurements on a 38.4 km crossbonded cable system. At...

  4. Online Location of Faults on AC Cables in Underground Transmission Systems

    Jensen, Christian Flytkjær

    deviations in the parameters of the OHL will result in large errors for fault location in the cable section. Field measurements showing the effect of short circuits on crossbonded systems conducted on parts of the electrical connection to the Anholt offshore wind farm are performed. The purpose is to examine...... whether neural networks can be trained using data from state-of-theart cable models to predict and estimate the fault location on crossbonded cables. Numerous measurements of different short circuits are carried out and it is concluded that the state-ofthe-art models predict general behaviour of the...... crossbonded system under fault conditions well, but the accuracy of the calculated impedance is low for fault location purposes. The neural networks can therefore not be trained and no impedance-based fault location method can be used for crossbonded cables or hybrid lines. The use of travelling wave...

  5. Online fault location on crossbonded AC cables in underground transmission systems

    F. Jensen, Christian; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2014-01-01

    In this paper, a fault locator system specifically designed for crossbonded cables is described. Electromagnetic wave propagation theory for crossbonded cables with focus on fault location purposes is discussed. Based on this, the most optimal modal component and input signal to the fault locator system are identified. The fault locator system uses the Wavelet Transform both to create reliable triggers in the units and to estimate the fault location based on time domain signals obtained in th...

  6. High Temperature Superconducting Underground Cable

    Farrell, Roger, A.

    2010-02-28

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the world’s first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  7. High Temperature Superconducting Underground Cable

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the worlds first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  8. Online fault location on crossbonded AC cables in underground transmission systems

    F. Jensen, Christian; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2014-01-01

    of a 245 kV crossbonded cable system, connecting the newly installed 400 MW Danish offshore wind farm Anholt to the main grid, are obtained and used to verify the proposed system. Furthermore, extensive simulation data created in PSCAD/EMTDC is used in order to examine the robustness of the system to......In this paper, a fault locator system specifically designed for crossbonded cables is described. Electromagnetic wave propagation theory for crossbonded cables with focus on fault location purposes is discussed. Based on this, the most optimal modal component and input signal to the fault locator...... system are identified. The fault locator system uses the Wavelet Transform both to create reliable triggers in the units and to estimate the fault location based on time domain signals obtained in the substations by two fault locator units. Field measurements of faults artificially created on a section...

  9. Online fault location on AC cables in underground transmission systems using screen currents

    Jensen, Christian Flytkjær; Nanayakkara, O.M.K.K; Rajapakse, Athula;

    This paper studies online travelling wave methods for fault location on a crossbonded cable system using screen currents. During the construction of the electrical connection to the 400 MW off shore wind farm Anholt, it was possible to perform measurements on a 38.4 km crossbonded cable system. At...... coils if the screen currents contain the necessary information for accurate fault location. In this paper, this is examined by analysis of field measurements and through a study of simulations. The wavelet transform and visual inspection methods are used and the accuracy is compared. Field measurements...

  10. 47 CFR 32.2422 - Underground cable.

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Underground cable. 32.2422 Section 32.2422... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2422 Underground cable. (a) This account shall include the original cost of underground cable installed in conduit and...

  11. EHV AC undergrounding electrical power performance and planning

    Benato, Roberto

    2010-01-01

    EHV AC Undergrounding Electrical Power discusses methods of analysis for cable performance and for the behaviour of cable, mixed and overhead lines. The authors discuss the undergrounding of electrical power and develop procedures based on the standard equations of transmission lines. They also provide technical and economical comparisons of a variety of cables and analysis methods, in order to examine the performance of AC power transmission systems. A range of topics are covered, including: energization and de-energization phenomena of transmission lines; power quality; and cable safety cons

  12. Modeling of long High Voltage AC Underground

    Gudmundsdottir, Unnur Stella; Bak, Claus Leth; Wiechowski, W. T.

    2010-01-01

    This paper presents the work and findings of a PhD project focused on accurate high frequency modelling of long High Voltage AC Underground cables. The project is cooperation between Aalborg University and Energinet.dk. The objective of the project is to investigate the accuracy of most up to date...... cable models, perform highly accurate field measurements for validating the model and identifying possible disadvantages of the cable model. Furthermore the project suggests and implements improvements and validates them against several field measurements. It is shown in this paper how a new method for...... calculating the frequency dependent cables impedance greatly improves the modeling procedure and gives a highly accurate result for high frequency simulations....

  13. 30 CFR 75.804 - Underground high-voltage cables.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground high-voltage cables. 75.804 Section... AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.804 Underground high-voltage cables. (a) Underground high-voltage cables used in...

  14. 30 CFR 57.4057 - Underground trailing cables.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground trailing cables. 57.4057 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control § 57.4057 Underground trailing cables. Underground trailing cables shall be accepted...

  15. 47 CFR 32.6422 - Underground cable expense.

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Underground cable expense. 32.6422 Section 32.6422 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM... Underground cable expense. (a) This account shall include expenses associated with underground cable....

  16. AC loss in superconducting tapes and cables

    Oomen, Marijn Pieter

    2000-01-01

    The present study discusses the AC loss in high-temperature superconductors. Superconducting materials with a relatively high critical temperature were discovered in 1986. They are presently developed for use in large-scale power-engineering devices such as power-transmission cables, transformers an

  17. Comparison of advanced high power underground cable designs

    In this paper, advanced high power underground cable designs are compared in the light of available literature, of reports and information supplied by participating industries (AEG, BICC, CGE, Pirelli, Siemens), spontaneous contributions by EdF, France, BBC and Felten and Guilleaume Kabelwerke A.G., Germany, and Hitachi, Furukawa, Fujikura and Sumitomo, Japan, and earlier studies carried out at German public research centres. The study covers cables with forced cooling by oil or water, SF6-cables, polyethylene cables, cryoresistive and superconducting cables. (orig.)

  18. AC loss in superconducting tapes and cables

    Oomen, Marijn Pieter

    High-temperature superconductors are developed for use in power-transmission cables, transformers and motors. The alternating magnetic field in these devices causes AC loss, which is a critical factor in the design. The study focuses on multi-filament Bi-2223/Ag tapes exposed to a 50-Hz magnetic field at 77 K. The AC loss is measured with magnetic, electric and calorimetric methods. The results are compared to theoretical predictions based mainly on the Critical-State Model. The loss in high- temperature superconductors is affected by their characteristic properties: increased flux creep, high aspect ratio and inhomogeneties. Filament intergrowths and a low matrix resistivity cause a high coupling-current loss especially when the filaments are fully coupled. When the wide side of the tape is parallel to the external magnetic field, the filaments are decoupled by twisting. In a perpendicular field the filaments can be decoupled only by combining a short twist pitch with a transverse resistivity much higher than that of silver. The arrangement of the inner filaments determines the transverse resistivity. Ceramic barriers around the filaments cause partial decoupling in perpendicular magnetic fields at power frequencies. The resultant decrease in AC loss is greater than the accompanying decrease in critical current. With direct transport current in alternating magnetic field, the transport-current loss is well described with a new model for the dynamic resistance. The Critical- State Model describes well the magnetisation and total AC loss in parallel magnetic fields, at transport currents up to 0.7 times the critical current. When tapes are stacked face-to-face in a winding, the AC-loss density in perpendicular fields is greatly decreased due to the mutual shielding of the tapes. Coupling currents between the tapes in a cable cause an extra AC loss, which is reduced by a careful cable design. The total AC loss in complex devices with many tapes is generally well

  19. Development of YBCO HTS cable with low AC loss

    High temperature superconducting (HTS) cables using YBCO tapes are expected to be more economical because AC losses will be much smaller than conventional cables. To reduce AC loss, 10 mm wide YBCO tapes were divided into five strips using a YAG laser. Using narrower strips and optimizing the space between the strips were effective in reducing AC loss. A 1 m conductor was fabricated, and AC loss was 0.048 W/m at 1 kA and 50 Hz. Based on the successful AC loss reduction in the 1 m conductor, we will fabricate a 10 m HTS cable with a three-layer HTS conductor, electrical insulation, and a one-layer HTS shield and cupper protection layer for overcurrent. In addition, we have developed a prototype of the HTS cable joint that can withstand an overcurrent condition of 31.5 kA for 2 s

  20. 30 CFR 75.822 - Underground high-voltage longwall cables.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground high-voltage longwall cables. 75... MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution High-Voltage Longwalls § 75.822 Underground high-voltage longwall cables. In addition to the...

  1. Energy dispatching analysis of lightning surges on underground cables in a cable connection station

    The paper aimed to simulate the transient over-voltage phenomena which occur at 345 kV and 161 kV underground cables, when lighting strikes on or near the cable connection station, by using the Electro-Magnetic Transients Program (EMTP). A feasibility study on changing related parameters, as well as cable connections and grounding methods to reduce the impact caused by lightning strikes, will be thoroughly conducted. The various components required for a detailed simulation including; lightning surges, transmission line and tower, arrester, and underground cables are all considered. Then, the transient voltage of the cables will be analyzed under different situations including; connection methods, grounding locations, length of the grounding wire of arrester, and the grounding resistance for different locations. The simulation results show that the length of the grounding wire is more sensitive to the transient over-voltage which occurred when a common grounding topology was adopted. In contrast, the use of an independent grounding topology resulted in a reduction of the grounding resistance, which effectively decreased the over-voltage, thereby avoiding surpassing the shielding voltage level of the cable, caused by the rise of ground voltage.

  2. Assessment of 69 kV Underground Cable Thermal Ratings using Distributed Temperature Sensing

    Stowers, Travis

    Underground transmission cables in power systems are less likely to experience electrical faults, however, resulting outage times are much greater in the event that a failure does occur. Unlike overhead lines, underground cables are not self-healing from flashover events. The faulted section must be located and repaired before the line can be put back into service. Since this will often require excavation of the underground duct bank, the procedure to repair the faulted section is both costly and time consuming. These added complications are the prime motivators for developing accurate and reliable ratings for underground cable circuits. This work will review the methods by which power ratings, or ampacity, for underground cables are determined and then evaluate those ratings by making comparison with measured data taken from an underground 69 kV cable, which is part of the Salt River Project (SRP) power subtransmission system. The process of acquiring, installing, and commissioning the temperature monitoring system is covered in detail as well. The collected data are also used to evaluate typical assumptions made when determining underground cable ratings such as cable hot-spot location and ambient temperatures. Analysis results show that the commonly made assumption that the deepest portion of an underground power cable installation will be the hot-spot location does not always hold true. It is shown that distributed cable temperature measurements can be used to locate the proper line segment to be used for cable ampacity calculations.

  3. Comparative Analysis of Thermography Studies and Electrical Measurement of Partial Discharges in Underground Power Cables

    Gonzalez-Parada, A.; Guzman-Cabrera, R.; Torres-Cisneros, M.; Guzman-Sepulveda, J. R.

    2015-09-01

    The principal cause of damage in underground power cable installations is partial discharge (PD) activity. PD is a localized non-linear phenomenon of electrical breakdown that occurs in the insulating medium sitting between two conducting materials, which are at different potentials. The damage to the insulating material is induced by the AC voltage to which the insulator is subjected during the discharge process, and it can be directly or indirectly measured by the charge displacement across the insulation and the cavity defect. Non-invasive detection techniques that help in identifying the onset of the discharge process are required as PD is a major issue in terms of maintenance and performance of underground power installations. The main locations of failure are the accessories at points of connection such as terminals or splices. In this article, a study of electrical detection of PD and image processing of thermal pictures is presented. The study was carried out by controllably inducing specific failures in the accessories of the installation. The temporal evolution of the PD signals was supported with thermal images taken during the test in order to compare the PD activity and thermal increase due to failure. The analysis of thermographic images allows location of the failure by means of intensity-based texture segmentation algorithms. This novel technique was found to be suitable for non-invasive detection of the PD activity in underground power cable accessories.

  4. Narrow strand YBCO Roebel cable for lowered AC loss

    We have constructed test lengths of Roebel cable from wide strips of second generation YBCO wire. The strand width is 2mm to allow for lowered AC losses in comparison with standard HTS wires. Up to 10 strands can be cut from the 40mm wide strip and assembled into a 10 strand cable with a transposition length of 90mm. Electrical measurements show good retention of critical current through the cutting and cabling processes. Initial AC loss measurements confirm the reduction expected from full width wire. Results from mechanical modeling are presented which have been used to optimise strand geometry to reduce stress concentrations. Manufacturing capability to produce up to 100m lengths has been demonstrated

  5. Experimental investigation of a.c. losses in cabled superconductors

    A.c. losses in multifilamentary composite superconducting strands and cables have been measured in adiabatic conditions for transverse field sweep rates up to 50 T s-1. Measurements were performed on NbTi and Nb3Sn conductors of several configurations and surface preparations: single strands, soldered strands and cables of varying degrees of compaction composed of bare strands, with CuNi barriers and strands with chrome plating. The experimental data agree well with existing loss models. The data suggests that the total cable loss grows as approx.= 1/(void)3 below void fractions of 40%. This observed cable loss dependence on void fraction does not agree well with a previously proposed model. (author)

  6. Non-invasive monitoring of underground power cables using Gaussian-enveloped chirp reflectometry

    In this paper, we introduce non-invasive Gaussian-enveloped linear chirp (GELC) reflectometry for the diagnosis of live underground power cables. The GELC reflectometry system transmits the incident signal to live underground power cables via an inductive coupler. To improve the spatial resolution of the GELC reflectometry, we used the multiple signal classification method, which is a super-resolution method. An equalizer, which is based on Wiener filtering, is used to compensate for the signal distortion due to the propagation characteristics of underground power cables and inductive couplers. The proposed method makes it possible to detect impedance discontinuities in live underground power cables with high spatial resolution. Experiments to find the impedance discontinuity in a live underground power cable were conducted to verify the performance of the proposed method. (paper)

  7. Research on communication system of underground safety management based on leaky feeder cable

    CHEN Jian-hong; ZHANG Tao; CHENG Yun-cai; ZHANG Han

    2007-01-01

    According to the current working status of underground safety management and production scheduling, the importance and existed problem of underground mine radio communication were summarized, and the basic principle and classification of leaky feeder cable were introduced and the characteristics of cable were analyzed specifically in depth, and the application model of radio communication system for underground mine safety management was put forward. Meanwhile, the research explanation of the system component, function and evaluation was provided. The discussion result indicates that communication system of underground mine safety management which is integrated two-way relay amplifier and other equipment has many communication functions, and underground mine mobile communication can be achieved well.

  8. Low AC Loss in a 3 kA HTS Cable of the Dutch Project

    Chevtchenko, Oleg; Zuijderduin, Roy; Smit, Johan; Willén, Dag; Lentge, Heidi; Thidemann, Carsten; Traeholt, Chresten; Melnik, Irina; Geschiere, Alex

    2012-01-01

    Requirements for a 6km long high temperature superconducting (HTS) AC power cable of the Amsterdam project are: a cable has to fit in an annulus of 160mm, with two cooling stations at the cable ends only. Existing solutions for HTS cables would lead to excessively high coolant pressure drop in th...

  9. Models for electromagnetic coupling of lightning onto multiconductor cables in underground cavities

    Higgins, Matthew Benjamin

    This dissertation documents the measurements, analytical modeling, and numerical modeling of electromagnetic transfer functions to quantify the ability of cloud-to-ground lightning strokes (including horizontal arc-channel components) to couple electromagnetic energy onto multiconductor cables in an underground cavity. Measurements were performed at the Sago coal mine located near Buckhannon, WV. These transfer functions, coupled with mathematical representations of lightning strokes, are then used to predict electric fields within the mine and induced voltages on a cable that was left abandoned in the sealed area of the Sago mine. If voltages reached high enough levels, electrical arcing could have occurred from the abandoned cable. Electrical arcing is known to be an effective ignition source for explosive gas mixtures. Two coupling mechanisms were measured: direct and indirect drive. Direct coupling results from the injection or induction of lightning current onto metallic conductors such as the conveyors, rails, trolley communications cable, and AC power shields that connect from the outside of the mine to locations deep within the mine. Indirect coupling results from electromagnetic field propagation through the earth as a result of a cloud-to-ground lightning stroke or a long, low-altitude horizontal current channel from a cloud-to-ground stroke. Unlike direct coupling, indirect coupling does not require metallic conductors in a continuous path from the surface to areas internal to the mine. Results from the indirect coupling measurements and analysis are of great concern. The field measurements, modeling, and analysis indicate that significant energy can be coupled directly into the sealed area of the mine. Due to the relatively low frequency content of lightning (< 100 kHz), electromagnetic energy can readily propagate through hundreds of feet of earth. Indirect transfer function measurements compare extremely well with analytical and computational models

  10. Installation of underground power transmission cables. Proceedings of a Department of Energy workshop

    None

    1979-06-01

    The proceedings of a Department of Energy-sponsored workshop in the installation of underground power transmission cables are reported. The workshop was held in Pittsburgh, Pennsylvania, October 2--5, 1978. Sixty-two participants, representing equipment manufacturers, utilities, contractors, universities, and government agencies, were divided into topic groups covering specific installation activities. Discussion was directed toward a review of the state of the art in underground cable installation, future equipment and technique development requirements, and the formulation of conclusions and recommendations. The principal technological problem for underground installation is the lack of ability to locate underground obstacles, principally in urban and suburban areas. Development of a sensing system to locate obstacles was given a high priority by nearly all topic groups. The lack of market definition was seen as the principal impediment to competition and development of specialized equipment. Most participants felt that the federal government must assume a role in research and development of new equipment and techniques. However, the participants did not favor increased federal regulation of underground cable installation systems.

  11. A Study on the Thermal Effect of the Current-Carrying Capacity of Embedded Underground Cable

    LI Dewen

    2012-10-01

    Full Text Available The current paper aims to study embedded underground cable and the effect of temperature that surrounds it. Determining the carrying capacity of the cable is important to predict the temperature changesin the embedded pipe. Simulating the temperature field and the laying environment according to the IEC standard enables the calculation of the carrying capacity of the buried region. According to the theoryof heat transfer, the embedded pipe tube model temperature field should be coupled with a numerical model. The domain and boundary conditions of the temperature field should also be determined using the 8.7/15kV YJV 400 cable. In conducting numerical calculation and analysis using the temperature field model, the two-dimensional temperature distribution of the emission control area should be determined. The experimental results show that the simulation isconsistent with the IEC standard. Furthermore, in identifying the cable ampacity, the different seasons and different cable rows should be taken into account using the finite element method. Finally, theappropriate choice of root and circuit numbers of the cable will improve the cable’s the carrying capacity.

  12. Detection and Location of Underground Power Cable using Magnetic Field Technologies

    Wang, P.; Goddard, K.F.; Lewin, P L; Swingler, S.G

    2011-01-01

    The location of buried underground electricity cables is becoming a major engineering and social issue worldwide. Records of utility locations are relatively scant, and even when records are available, they almost always refer to positions relative to ground-level physical features that may no longer exist or that may have been moved or altered. The lack of accurate positioning records of existing services can cause engineering and construction delays and safety hazards when new construction,...

  13. The scaling of transport AC losses in Roebel cables with varying strand parameters

    A Roebel cable is a good candidate for low-voltage windings in a high-temperature superconductor (HTS) transformer because of its high current-carrying capability and low AC loss. Transport AC loss measurements were carried out in 1.8 m long 15/5 (fifteen 5 mm wide strands) and 15/4 Roebel cables. The results were compared with those in many Roebel cables composed of 2 mm wide Roebel strands. Comparison of the AC losses hinted that the intrinsic difference in normalized transport AC losses is due to differences in the g/w (ratio of the horizontal gap between the Roebel strands over the Roebel strand width) values. The intrinsic difference was confirmed by measuring transport AC loss in a series of horizontally arranged parallel conductor pairs with various g values. A method to scale transport AC losses in Roebel cables with varying strand parameters was developed. The scaling method will be useful for a rough assessment of AC loss in one-layer solenoid winding coils, such as in a HTS transformer. (papers)

  14. Development and Improvement of an Intelligent Cable Monitoring System for Underground Distribution Networks Using Distributed Temperature Sensing

    Jintae Cho

    2014-02-01

    Full Text Available With power systems switching to smart grids, real-time and on-line monitoring technologies for underground distribution power cables have become a priority. Most distribution components have been developed with self-diagnostic sensors to realize self-healing, one of the smart grid functions in a distribution network. Nonetheless, implementing a real-time and on-line monitoring system for underground distribution cables has been difficult because of high cost and low sensitivity. Nowadays, optical fiber composite power cables (OFCPCs are being considered for communication and power delivery to cope with the increasing communication load in a distribution network. Therefore, the application of distributed temperature sensing (DTS technology on OFCPCs used as underground distribution lines is studied for the real-time and on-line monitoring of the underground distribution power cables. Faults can be reduced and operating ampacity of the underground distribution system can be increased. This paper presents the development and improvement of an intelligent cable monitoring system for the underground distribution power system, using DTS technology and OFCPCs as the underground distribution lines in the field.

  15. On the Degradation Mechanism of Low-Voltage Underground Cable with Poly(Vinyl Chloride) Insulation

    Tawancy, H. M.; Hassan, M.

    2016-06-01

    A study has been undertaken to determine the degradation mechanism leading to localized short-circuit failures of an underground low-voltage cable with PVC insulation. It is shown that that the insulation of outer sheath and conductor cores has been cracked by thermal degradation involving dehydrochlorination, oxidation, and loss of plasticizers leading to current leakage between the cores. Most evidence points out that overheating due to poor connection of copper wires as well as a chemically active soil has caused the observed degradation.

  16. Full Scale Test on a 100km, 150kV AC Cable

    Faria da Silva, Filipe Farria; Wiechowski, W.; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2010-01-01

    This paper presents some of the results obtained from the electrical measurements on a 99.7 km, 150 kV three-phase AC cable, connecting 215 MW offshore wind farm Horns Rev 2, located in Denmark west coast, to Denmark's 400 kV transmission network. The measurements were performed at nominal voltag...

  17. Theory of AC Loss in Cables with 2G HTS Wire

    Clem, J.R.; Malozemoff, A.P.

    2009-09-13

    While considerable work has been done to understand AC losses in power cables made of first generation (1G) high temperature superconductor (HTS) wires, use of second generation (2G) HTS wires brings in some new considerations. The high critical current density of the HTS layer 2G wire reduces the surface superconductor hysteretic losses. Instead, gap and polygonal losses, flux transfer losses in imbalanced two layer cables and ferromagnetic losses for wires with NiW substrates constitute the principal contributions. Current imbalance and losses associated with the magnetic substrate can be minimized by orienting the substrates of the inner winding inward and the outer winding outward.

  18. Magnetic fields and childhood cancer: an epidemiological investigation of the effects of high-voltage underground cables.

    Bunch, K J; Swanson, J; Vincent, T J; Murphy, M F G

    2015-09-01

    Epidemiological evidence of increased risks for childhood leukaemia from magnetic fields has implicated, as one source of such fields, high-voltage overhead lines. Magnetic fields are not the only factor that varies in their vicinity, complicating interpretation of any associations. Underground cables (UGCs), however, produce magnetic fields but have no other discernible effects in their vicinity. We report here the largest ever epidemiological study of high voltage UGCs, based on 52,525 cases occurring from 1962-2008, with matched birth controls. We calculated the distance of the mother's address at child's birth to the closest 275 or 400 kV ac or high-voltage dc UGC in England and Wales and the resulting magnetic fields. Few people are exposed to magnetic fields from UGCs limiting the statistical power. We found no indications of an association of risk with distance or of trend in risk with increasing magnetic field for leukaemia, and no convincing pattern of risks for any other cancer. Trend estimates for leukaemia as shown by the odds ratio (and 95% confidence interval) per unit increase in exposure were: reciprocal of distance 0.99 (0.95-1.03), magnetic field 1.01 (0.76-1.33). The absence of risk detected in relation to UGCs tends to add to the argument that any risks from overhead lines may not be caused by magnetic fields. PMID:26344172

  19. New piercing for insulated cables in underground networks; Novos conectores compactos perfurantes ('piercings') para cabos isoldados em redes subterraneas

    Moreno, Fernando; Corral, Horacio [Tradis, SP (Brazil). E-mail: tradis@mandic.com.br

    1999-07-01

    This work presents a tap and transition connection in low voltage protected underground cables. This connection allows tapping for clients or branchings from a main energized cables. The compact connectors range various types of insulated cables protected and under grounded in a simple way. The work analysed the advantages of using two components polyurethane resins for the tapping protection and insulation restoring.

  20. Experimental study of thermal field deriving from an underground electrical power cable buried in non-homogeneous soils

    The electrical cables ampacity mainly depends on the cable system operation temperature. To achieve a better cable utilization and reduce the conservativeness typically employed in buried cable design, an accurate evaluation of the heat dissipation through the cables and the surrounding soil is important. In the traditional method adopted by the International Electrotechnical Commission (IEC) and the Institute of Electrical and Electronics Engineers (IEEE) for the computation of the thermal resistance between an existing underground cable system and the external environment, it is still assumed that the soil is homogeneous and has uniform thermal conductivity. Numerical studies have been conducted to predict the temperature distribution around the cable for various configurations and thermal properties of the soil. The paper presents an experimental study conducted on a scale model to investigate the heat transfer of a buried cable, with different geometrical configurations and thermal properties of the soil, and to validate a simplified model proposed by the authors in 2012 for the calculation of the thermal resistance between the underground pipe or electrical cable and the ground surface, in cases where the filling of the trench is filled with layers of materials with different thermal properties. Results show that experimental data are in good agreement with the numerical ones. -- Highlights: • Heat transfer of a buried cable has been experimentally studied on a scale model. • Different configurations and thermal properties of the soil have been tested. • Authors previously proposed a simplified model and obtained numerical results. • Experimental results and numerical ones previously obtained were in accordance

  1. Numerical simulation of coupled heat, liquid water and water vapor in soils for heat dissipation of underground electrical power cables

    The trend towards renewable energy comes along with a more and more decentralized production of electric energy. As a consequence many countries will have to build hundreds or even thousands of miles of underground transmission lines during the next years. The lifetime of a transmission line system strongly depends on its temperature. Therefore an accurate calculation of the cable temperature is essential for estimating and optimizing the system's lifetime. The International Electrotechnical Commission and the Institute of Electronics and Electrical Engineers are still employing classic approaches, dating back from the 1950s, that are missing fundamental phenomena involved in heat transport in soils. In recent years several authors [4,37] pointed out that for a proper computation of heat transport in soils, physical processes describing heat, liquid water and vapor transport must be coupled and the respective environmental weather conditions need to be considered. In this study we present a numerical model of coupled liquid water, vapor and heat flow, to describe heat dissipation from underground cables. At first the model is tested and validated on a downscaled experiment [32], secondly the model is applied on a simplified system to demonstrate the strong relation of the cable temperature on soil water content and finally the model is applied using real weather conditions to demonstrate that small changes in the design of underground transmission line systems can lead to considerable improvements in both average as well as peak-to-peak temperatures. - Highlights: • Wind farms and heat dissipation in underground power cables. • Cable lifetime, cable temperature and properties of surrounding soil. • Coupled model for heat dissipation, liquid water and vapor transport in soils. • Numerical simulation under real weather conditions. • Cable temperature depending on construction of transmission line system

  2. AC loss performance of cable-in-conduit conductor. Influence of cable mechanical property on coupling loss reduction

    The ITER Central Solenoid (CS) model coil, CS Insert and Nb3Al Insert were developed and tested from 2000 to 2002. The AC loss performances of these coils were investigated in various experiments. In addition, the AC losses of the CS and Nb3Al Insert conductors were measured using short CS and Nb3Al Insert conductors before the coil tests. The coupling time constants of these conductors were estimated to be 30 and 120 ms, respectively. On the other hand, the test results of the CS and Nb3Al Inserts show that the coupling currents induced in these conductors had multiple decay time constants. In fact, the existence of the coupling currents with long decay time constants, the order of which was in the thousands of seconds, was directly observed with hall sensors and voltage taps. Moreover, the AC loss test results show that electromagnetic force decreases coupling losses with exponential decay constants. This is because the weak sinter among the strands, which originated during heat treatment, was broken due to the electromagnetic force, and then the contact resistance among strands increased. It was found that this exponential decay constant was the function of a gap (i.e., a mechanical property of the cable) created between the cable and conduit due to electromagnetic force. The gap can be estimated by pressure drop, measured under the electromagnetic force. The pressure drop can easily be measured at an initial trial charge, and then it is possible to estimate the exponential decay constant before normal coil operation. Accordingly, it is possible to predict promptly how many times the trial operations are necessary to decrease the coupling losses to the designed value by measuring the coupling losses and the pressure drop during the initial coil operation trial. (author)

  3. Earth return path impedances of underground cable for three-layer earth

    B. HEMMATIAN; B. VAHIDI; S. H. HOSSEINIAN

    2009-01-01

    One of the factors that affect the parameters of an underground cable is earth return path impedance. Pollaczek developed a formula for the case of one-layer (homogenous) earth. But in practice the earth is composed of several layers. In this study we develop a new formula for earth return path impedance in the case of a three-layer earth. To check the accuracy of the obtained results, a comparison has been made with the finite element method (FEM). A comparison between the results of the Poilaczek formula and results of the obtained formula for a three-layer earth has been made, showing that the use of the Pollaczek formula instead of the actual formula can cause serious errors.

  4. Interstrand and AC-loss measurements on Rutherford-type cables for accelerator magnet applications

    Otmani, R; Tixador, P

    2001-01-01

    One of the main issues for particle accelerator magnets is the control of interstrand resistances. Too low resistances result in large coupling currents during ramping, which distort field quality, while too large resistances may prevent current redistribution among cable strands, resulting in degraded quench performance. In this paper, we review a series of interstrand resistance and AC-loss measurements performed on four Rutherford-type cables. The four cables have the same number of strands and similar outer dimensions, corresponding to LHC quadrupole cable specifications. The first cable is made from NbTi strands, coated with silver-tin alloy, the second one is made from bare Nb/sub 3/Sn strands, the third one is made also from bare Nb/sub 3/Sn strands but includes a 25- mu m-thick stainless steel core between the strand layers, and the last one is made from Nb/sub 3/Sn strands plated with chromium. To cross-check the two measurement types and assess their consistency, we compare the coupling-current time...

  5. External electromagnetic transient sources: analysis of its effect in underground power cables; Fuentes transitorias electromagneticas externas: analisis de su efecto en los cables de potencia subterraneos

    Escamilla Paz, Antonio

    2009-07-01

    In most of the electrical power systems that operate at present, the subterranean cables are only a complement. The cost of these cables is generally higher than the one of the aerial power lines, thus its use is restricted only to those areas where the construction of the aerial power lines is not feasible. It is estimated that for voltages lower than 110 kV this cost is up to seven times greater than the one of an aerial power line and for voltages higher than 380 kV it can be up to twenty times greater. Nevertheless, important reasons exist to construct a subterranean cable system such as: a) the fast growth of the urban centers and the industrial zones, which brings about restrictions of the rights of way for the construction of aerial power lines, b) the crossing of large water bodies, c) the congestion of aerial power lines near the generating substations or power plants, d) the crossing of air lines and e) the laws and the regulations, to mention some of them. The importance of the underground transmission systems of high and extra high voltage will be increased in the medium and the long term, therefore, it is considered that the effects of the external phenomena in these systems, like the inductions produced by the electromagnetic transient sources, will be more severe. In this research work the atmospheric discharges are defined as the external electromagnetic transient sources. The large dimension cables such as the power cables, behave as large collectors of the interferences produced by the atmospheric discharges, which can bring about damages in the components of a system. In order to avoid the damages and to increase the reliability of the subterranean cable systems it is necessary to use protective devices and appropriate insulation levels, mainly. If the phenomenon and the behavior of the system are properly represented, it is possible to more accurately determine the characteristics that the equipment must have to resist the over voltages and the

  6. Theory of ac loss in power transmission cables with second generation high temperature superconductor wires

    While a considerable amount of work has been done in an effort to understand ac losses in power transmission cables made of first generation high temperature superconductor (HTS) wires, use of second generation (2G) HTS wires brings in some new considerations. The high critical current density of the HTS layer in 2G wires reduces the surface superconductor hysteretic losses, for which a new formula is derived. Instead, gap and polygonal losses, flux transfer losses in imbalanced two-layer cables and ferromagnetic losses for wires with NiW substrates constitute the principal contributions. A formula for the flux transfer losses is also derived with a paramagnetic approximation for the substrate. Current imbalance and losses associated with the magnetic substrate can be minimized by orienting the substrates of the inner winding inward and the outer winding outward.

  7. Quantification of the heat dissipation of underground medium and low-voltage cables; Quantifizierung der Waermeableitung bei erdverlegten Mittel- und Niederspannungskabeln

    Stegner, Johannes; Drefke, Christof; Sass, Ingo [Technische Univ. Darmstadt (Germany). Inst. fuer Angewandte Geowissenschaften; Hentschel, Klaus [E.ON Bayern AG, Regensburg (Germany)

    2013-06-01

    The performance of underground power cables depends on its operational warming. In a research project, the influence of soil and bedding materials on this performance is investigated in consideration of climate, weather and water balance of the site.

  8. Measuring ac losses in superconducting cables using a resonant circuit:Resonant current experiment (RESCUE)

    Däumling, Manfred; Olsen, Søren Krüger; Rasmussen, Carsten;

    1998-01-01

    A simple way to obtain true ac losses with a resonant circuit containing a superconductor, using the decay of the circuit current, is described. For the measurement a capacitor is short circuited with a superconducting cable. Energy in the circuit is provided by either charging up the capacitors...... with a certain voltage, or letting a de flow in the superconductor. When the oscillations are started-either by opening a switch in case a de is flowing or by closing a switch to connect the charged capacitors with the superconductor-the current (via a Rogowski coil) or the voltage on the capacitor can...

  9. Double Layered Sheath in Accurate HV XLPE Cable Modeling

    Gudmundsdottir, Unnur Stella; Silva, J. De; Bak, Claus Leth;

    2010-01-01

    This paper discusses modelling of high voltage AC underground cables. For long cables, when crossbonding points are present, not only the coaxial mode of propagation is excited during transient phenomena, but also the intersheath mode. This causes inaccurate simulation results for high frequency...

  10. Identification of problems when using long high voltage AC cable in transmission system I: Switching transient problems

    Rahimi, Saeed; Wiechowski, W.; Randrup, M;

    2008-01-01

    the proper substitution and solution which make the transmission expansion possible with minimized visual impacts on the communities. Within European countries, Denmark was been at the forefront of replacing the transmission lines with cables. The project was supplying the power to the greater......Due to political and environmental pressures from the public and government side, upgrading and building new transmission facilities are becoming more and more difficult and in some cases the expansion of overhead transmission lines are impossible. This means that underground cable technology is...

  11. Power applications for superconducting cables in Denmark

    Tønnesen, Ole; Østergaard, Jacob; Olsen, S. Krüger

    1999-01-01

    In Denmark a growing concern for environmental protection has lead to wishes that the open country is kept free of overhead lines as far as possible. New lines under 100 kV and existing 60/50 kV lines should be established as underground cables. Superconducting cables represent an interesting...... alternative to conventional cables, as they are able to transmit two or more times the energy than a conventional cable. HTS cables with a room temperature dielectric design are especially interesting as a target for replacing overhead lines. Superconducting cables in the overall network are of interest in...... cases such as transmission of energy into cities and through areas of special interest. The planned large groups of windmills in Denmark generating up to 2000 MVA or more both on dry land and off-shore will be an obvious case for the application of superconducting AC or DC cables. These opportunities...

  12. Techniques and equipment for detecting and locating incipient faults in underground power transmission cable systems. First technical progress report, 21 August 1978-31 March 1979

    Phillips, A.C.; Nanevicz, J.E.; Adamo, R.C.; Cole, C.A.; Honey, S.K.; Petro, J.P.

    1979-05-01

    This work is to provide practical methods for detecting and locating incipient faults in energized and deenergized underground power transmission cable systems. Radio-frequency probing techniques are emphasized. Supporting tasks include measurements of cable characteristics at manufacturing plants and utility installations, field evaluation, development of signal couplers to access transmission lines, and a study of methods leading to technically effective and economical use of incipient-fault locators.

  13. Numerical simulation of heat dissipation processes in underground power cable system situated in thermal backfill and buried in a multilayered soil

    Highlights: • A practical thermal analysis of underground power cable system. • The geological measurements were performed for cable line placement location. • Dry zone formation effect included in soil and FTB thermal conductivity formula. • A simplified FEM model of underground power cable system. • The computational numerical code validation with ANSYS. - Abstract: This paper presents the thermal analysis of the underground transmission line, planned to be installed in one of the Polish power plants. The computations are performed by using the Finite Element Method (FEM) code, developed by the authors. The paper considers a system of three power cables arranged in flat (in-line) formation. The cable line is buried in the multilayered soil. The soil layers characteristic and thermal properties are determined from geological measurements. Different conditions of cable bedding are analyzed including power cables placement in the FTB or direct burial in a mother ground. The cable line burial depth, measured from the ground level, varies from 1 m to 2.5 m. Additionally, to include the effect of dry zones formation on the temperature distribution in cable line and surroundings, soil and FTB thermal conductivities are considered as a temperature-dependent. The proposed approach for determining the temperature-dependent thermal conductivity of soil layers is discussed in detail. The FEM simulation results are also compared with the results of the simulation that consider soil layers as homogeneous materials. Therefore, thermal conductivity is assumed to be constant for each layer. The results obtained by using the FEM code, developed by the authors, are compared with the results of ANSYS simulations, and a good agreement was found

  14. Failure evaluation of underground high voltage cables (115 kV) in Mazatlan, Sinaloa: Microscopic method

    Valero-Huerta, M.A.; Ramirez-Delgado, R. [Lab. de Pruebas de Equipos y Materiales, Irapuato (Mexico)

    1995-11-01

    The present paper is a complete analysis of the failure which occurred to the 115 kV power cable installed between the Mazatlan Centro and Mazatlan Norte Substations. Laboratory analysis that established the causes of the failure are included. It was concluded that the failure of the cable was provoked by the entrance of sewage water to the screen, and due to the presence of anaerobic organisms, resulted in the formation of sulfidic acid, which caused the severe corrosion that can be observed in the screen. The resulting loss of conductivity provoked heating capable of melting the isolator until its rupture.

  15. Ac loss modelling and measurement of superconducting transformers with coated-conductor Roebel-cable in low-voltage winding

    Pardo, Enric; Staines, Mike; Jiang, Zhenan; Glasson, Neil

    2015-11-01

    Power transformers using a high temperature superconductor (HTS) ReBCO coated conductor and liquid nitrogen dielectric have many potential advantages over conventional transformers. The ac loss in the windings complicates the cryogenics and reduces the efficiency, and hence it needs to be predicted in its design, usually by numerical calculations. This article presents detailed modelling of superconducting transformers with Roebel cable in the low-voltage (LV) winding and a high-voltage (HV) winding with more than 1000 turns. First, we model a 1 MVA 11 kV/415 V 3-phase transformer. The Roebel cable solenoid forming the LV winding is also analyzed as a stand-alone coil. Agreement between calculations and experiments of the 1 MVA transformer supports the model validity for a larger tentative 40 MVA 110 kV/11 kV 3-phase transformer design. We found that the ac loss in each winding is much lower when it is inserted in the transformer than as a stand-alone coil. The ac loss in the 1 and 40 MVA transformers is dominated by the LV and HV windings, respectively. Finally, the ratio of total loss over rated power of the 40 MVA transformer is reduced below 40% of that of the 1 MVA transformer. In conclusion, the modelling tool in this work can reliably predict the ac loss in real power applications.

  16. Modelling of long High Voltage AC Cables in the Transmission System

    Gudmundsdottir, Unnur Stella

    for comparison at the measuring site. Measurements are performed on a 400 kV 7.6 km long cable, which is a part of a hybrid OHL/cable transmission line. The cables are laid in flat formation and have been in operation for several years. For performing the measurements, the cables are disconnected from...... time. From analysing the modal currents, the source of deviation is identified. The same phenomena and source for deviation between field measurements and simulation results is identified for a 400 kV flat formation crossbonded 7.6 km cable line, a 150 kV tight trefoil crossbonded 2.5 km cable line and...... a way, that the impedance matrix is no longer calculated from the analytical equations but from a finite element method including the proximity effect. A MATLAB program is constructed in order to calculate the impedance matrix based on the finite element method. Furthermore, this MATLAB program also...

  17. Line Differential Protection Scheme Modelling for Underground 420 kV Cable Systems

    Sztykiel, Michal; Bak, Claus Leth; Wiechowski, Wojciech;

    2010-01-01

    Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a new approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows to create complex and accurate relay models derived from the original algorithms. Relay mode......-simulated and real world generated current signals connected to the relay.......Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a new approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows to create complex and accurate relay models derived from the original algorithms. Relay models...... can be applied with various systems, allowing to obtain the most optimal configuration of the protective relaying. The present paper describes modelling methodology on the basis of Siemens SIPROTEC 4 7SD522/610. Relay model was verified experimentally with its real equivalent by both EMTP...

  18. Line Differential Protection Scheme Modelling for Underground 420 kV Cable Systems

    Sztykiel, Michal; Bak, Claus Leth; Dollerup, Sebastian

    2011-01-01

    Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a detailed approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows to create complex and accurate relay models derived from the original algorithms. Relay......-simulated and real world generated current signals connected to the relay.......Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a detailed approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows to create complex and accurate relay models derived from the original algorithms. Relay...... models can be applied with various systems, allowing to obtain the most optimal configuration of the protective relaying. The present paper describes modelling methodology on the basis of Siemens SIPROTEC 4 7SD522/610. Relay model was verified experimentally with its real equivalent by both EMTP...

  19. Condition assessment of power cables using partial discharge diagnosis at damped AC voltages

    Wester, F.J.

    2004-01-01

    The thesis focuses on the condition assessment of the distribution power cables, which have a very critical part in the distribution of electrical power over regional distances. The majority of the outages in the power system is related to the distribution cables, of which for more than 60% to internal defects. The material degradation in the power cables can be categorised into four local degradation processes, which are related to partial discharges. Partial discharge characteristics theref...

  20. Line Differential Protection Scheme Modelling for Underground 420 kV Cable Systems

    Sztykiel, Michal; Bak, Claus Leth; Dollerup, Sebastian

    2011-01-01

    Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a detailed approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows to create complex and accurate relay models derived from the original algorithms. Relay models can be applied with various systems, allowing to obtain the most optimal configuration of the protective relaying. The present paper describes modelling methodology on the basis of Siemens SIP...

  1. A nontrivial factor in determining current distribution in an ac HTS cable-proximity effect

    2010-01-01

    A superconductor has zero resistance at the superconducting state. This unique property creates many exceptional phenomena, of which some are known and the others are not. Our experiments with multilayer high temperature superconductor (HTS) cable samples revealed a new phenomenon that alternating current had a tendency to flow in the inner and outer layers of the cables. We attribute the cause of this phenomenon to the electromagnetic interaction in an infinite electrical conductivity medium and term it "super-proximity-effect". This effect will greatly affect the performance of a multilayer superconducting cable and other superconducting devices which are involved with alternating current transportation.

  2. An EMC Evaluation of the Use of Unshielded Motor Cables in AC Adjustable Speed Drive Applications

    Hanigovszki, Norbert; Poulsen, J.; Spiazzi, G.;

    2004-01-01

    -phase applications the occurrence of common-mode voltage is inherent due to asymmetrical output pulses. As a result, for electromagnetic compatibility (EMC) reasons, in most applications shielded cables are used between the inverter and the motor, implying high installation costs. The present paper discusses the use...... of cheaper, unshielded cables. A new method for measuring electromagnetic interference (EMI) from unshielded cables is proposed and measurement results are presented. The level of EMI is evaluated in different situations: without an output filter, with a classical LC output filter and with an...

  3. Development of buried cable location survey system by underground rader for power distribution cables under pavements. Haiden chichuka no tame no chika radar ni yoru maisetsukan tansa system no kaihatsu

    Suzuki, K.; Kitano, K.

    1990-06-01

    To execute construction work for power distribution cables under pavements reasonably, it is important to develop a technology capable of non-destructive detection of the location of existing buried cables from the ground surface. This study is to clarify the principle, measurement method, effectiveness, and limitation of the underground radar system which is at present considered as the most effective survey method for buried cables. In this system, accuracy in measuring the depth of underground cable location by a separated type antenna has been improved, software to improve resolution by a migration process has been developed, and a compact survey system which can analyze the data on the site has been realized. As aresult of the survey at city areas, all pipes buried less than 1m in depth with the resistivity value of more than 100 {Omega} m were detected as well as those less than 2m in depth with more than some 100 {Omega} m. However, non-metal pipes buried deeper than 1m in the ground of less than 100 {Omega} m were not detected. Consequently, improvement of the system is necessary in future. 7 refs., 23 figs., 6 tabs.

  4. UNDERGROUND

    Full text: Cossetted deep underground, sheltered from cosmic ray noise, has always been a favourite haunt of neutrino physicists. Already in the 1930s, significant limits were obtained by taking a geiger counter down in Holborn 'tube' station, one of the deepest in London's underground system. Since then, neutrino physicists have popped up in many unlikely places - gold mines, salt mines, and road tunnels deep under mountain chains. Two such locations - the 1MB (Irvine/ Michigan/Brookhaven) detector 600 metres below ground in an Ohio salt mine, and the Kamiokande apparatus 1000m underground 300 km west of Tokyo - picked up neutrinos on 23 February 1987 from the famous 1987A supernova. Purpose-built underground laboratories have made life easier, notably the Italian Gran Sasso Laboratory near Rome, 1.4 kilometres below the surface, and the Russian Baksan Neutrino Observatory under Mount Andyrchi in the Caucasus range. Gran Sasso houses ICARUS (April, page 15), Gallex, Borexino, Macro and the LVD Large Volume Detector, while Baksan is the home of the SAGE gallium-based solar neutrino experiment. Elsewhere, important ongoing underground neutrino experiments include Soudan II in the US (April, page 16), the Canadian Sudbury Neutrino Observatory with its heavy water target (January 1990, page 23), and Superkamiokande in Japan (May 1991, page 8)

  5. Optimal Selection of AC Cables for Large Scale Offshore Wind Farms

    Hou, Peng; Hu, Weihao; Chen, Zhe

    2014-01-01

    platform in Matlab. A real offshore wind farm is chosen as the study case to demonstrate the proposed method. Furthermore, the optimization is also applied to an offshore wind farm under development. It can be observed from the results that the proposed optimal cable selection framework is an efficient and...

  6. Tunnel Boring Machine Cutter Maintenance for Constructing Underground Cable Lines from Nuclear Power Plants

    The tunnel boring machine (TBM) can construct an underground tunnel efficiently and without construction noise vibration related problems. Many civil projects, such as NPP construction, set importance on the economics of construction. Thus, advance rate, which is the speed at which the TBM is able to progress along its intended route, is one of the key factors affecting construction period and construction expenses. As the saying goes, time is money. Right Double Quotation Mark In addition, it is important to manage construction permits and civil complaints, even when construction expenses and construction periods are excluded. So, accurate prediction for advance rate is important when designing tunnel project. Several designers and project owners have tried to improve construction efficiency and tunneling advance rate.. There have been several studies on managing the rate of wear, designing an optimum tunnel face, and finding the optimum cutter spacing. Cutter replacements due to cutter wear and tear are very important because the wear and tear of cutters attached to the cutter head profoundly affect the advance rate. To manage cutter wear and tear is to control parameters related to cutter shape and cutter wear rate. There have been studies on the relationship between rock properties or TBM characteristics, and cutter wear or replacement. However, many of these studies relied on computer simulations or other small scale experiments. Therefore, this paper attempts to present a correlation between cutter replacement or cutter wear, against various parameters using practical data such as rock quality and TBM shield specifications, from an actual construction site. This study was conducted to suggest directions in the improvement of TBM cutters by analyzing relationships between rock conditions and cutter maintenance as well as TBM advance rates. Actual field data was collected and compared to actual design values in evaluating the effectiveness of traditional

  7. Tunnel Boring Machine Cutter Maintenance for Constructing Underground Cable Lines from Nuclear Power Plants

    Lee, Jae Wang; Yee, Eric [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-10-15

    The tunnel boring machine (TBM) can construct an underground tunnel efficiently and without construction noise vibration related problems. Many civil projects, such as NPP construction, set importance on the economics of construction. Thus, advance rate, which is the speed at which the TBM is able to progress along its intended route, is one of the key factors affecting construction period and construction expenses. As the saying goes, time is money. Right Double Quotation Mark In addition, it is important to manage construction permits and civil complaints, even when construction expenses and construction periods are excluded. So, accurate prediction for advance rate is important when designing tunnel project. Several designers and project owners have tried to improve construction efficiency and tunneling advance rate.. There have been several studies on managing the rate of wear, designing an optimum tunnel face, and finding the optimum cutter spacing. Cutter replacements due to cutter wear and tear are very important because the wear and tear of cutters attached to the cutter head profoundly affect the advance rate. To manage cutter wear and tear is to control parameters related to cutter shape and cutter wear rate. There have been studies on the relationship between rock properties or TBM characteristics, and cutter wear or replacement. However, many of these studies relied on computer simulations or other small scale experiments. Therefore, this paper attempts to present a correlation between cutter replacement or cutter wear, against various parameters using practical data such as rock quality and TBM shield specifications, from an actual construction site. This study was conducted to suggest directions in the improvement of TBM cutters by analyzing relationships between rock conditions and cutter maintenance as well as TBM advance rates. Actual field data was collected and compared to actual design values in evaluating the effectiveness of traditional

  8. AC loss in high-temperature superconducting conductors, cables and windings for power devices

    High-temperature superconducting (HTS) transformers and reactor coils promise decreased weight and volume and higher efficiency. A critical design parameter for such devices is the AC loss in the conductor. The state of the art for AC-loss reduction in HTS power devices is described, starting from the loss in the single HTS tape. Improved tape manufacturing techniques have led to a significant decrease in the magnetization loss. Transport-current loss is decreased by choosing the right operating current and temperature. The role of tape dimensions, filament twist and resistive matrix is discussed and a comparison is made between state-of-the-art BSCCO and YBCO tapes. In transformer and reactor coils the AC loss in the tape is influenced by adjacent tapes in the coil, fields from other coils, overcurrents and higher harmonics. These factors are accounted for by a new AC-loss prediction model. Field components perpendicular to the tape are minimized by optimizing the coil design and by flux guidance pieces. High-current windings are made of Roebel conductors with transposed tapes. The model iteratively finds the temperature distribution in the winding and predicts the onset of thermal instability. We have fabricated and tested several AC windings and used them to validate the model. Now we can confidently use the model as an engineering tool for designing HTS windings and for determining the necessary tape properties

  9. Water treeing in underground power cables: modelling of the trees and calculation of the electric field perturbation

    Acedo García, Miguel; Radu, I.; Frutos Rayego, Fabián; Filippini, Jean César; Notingher, P.

    2001-01-01

    In order to explain the development of different types of water trees and the related dielectric breakdowns in extruded power cables, it is necessary to analyse the dielectric properties of the corresponding treed regions and their influence on the distribution of electric field. The study presented in this paper is both experimental and theoretical. Experimentally, we performed the laboratory ageing of a power cable for accelerated conditions of applied voltage and frequency: ...

  10. Power System Technical Performance Issues Related to the Application of Long HVAC Cables

    Bak, Claus Leth

    The aim of this TB is to serve as a practical guide for preparing models and performing studies necessary during the assessment of the technical performance of HV/EHV systems with a large share of (long) AC cables. The brochure follows all phases of planning and analysis of a typical underground...

  11. Line Differential Protection Scheme Modelling for Underground 420 kV Cable Systems, EMTDC/PSCAD Relays Modelling

    Bak, Claus Leth; Sztykiel, Michal; Dollerup, Sebastian

    2011-01-01

    Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a new approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows creating complex and accurate relay models derived from the original algorithms. Relay model......-simulated and real world generated current signals connected to the relay.......Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a new approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows creating complex and accurate relay models derived from the original algorithms. Relay models...... can be applied with various systems, allowing obtaining the most optimal configuration of the protective relaying. The present paper describes modelling methodology on the basis of Siemens SIPROTEC 4 7SD522/610. Relay model was verified experimentally with its real equivalent by both EMTP...

  12. Line Differential Protection Scheme Modelling for Underground 420 kV Cable Systems:EMTDC/PSCAD Relays Modelling

    Sztykiel, Michal; Bak, Claus Leth; Wiechowski, Wojciech; Dollerup, Sebastian

    2010-01-01

    Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a new approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows to create complex and accurate relay models derived from the original algorithms. Relay models can be applied with various systems, allowing to obtain the most optimal configuration of the protective relaying. The present paper describes modelling methodology on the basis of Siemens SIPROTEC...

  13. A flexible super conducting ac cable: radial thermal contraction and the x-ray examination of a sample length of cold core

    The temperature reduction which a superconducting cable core will have to undergo following its manufacture and installation is nearly 300 K before it can be used. The satisfactory accommodation of the corresponding significant amount of thermal contraction of its component parts is therefore of major importance. This paper is concerned with such thermal contraction upon cooling of a flexible superconducting ac cable core comprising helically laid strip conductors of niobium clad copper and a polyethylene tape dielectric with electrostatic screens and bedding layers. A method is described of designing, for a controlled amount of radial contraction, a core held at near constant length. A report is also given of the x-ray examination of a sample core used for voltage tests. The relevance of the results to some other designs of core is discussed. (author)

  14. Design procedure and operation experience of data acquisition and control system for 22.9 kV underground HTS power cable

    Ryoo, H. S.; Sohn, S. H.; Hwang, S. D.; Lim, J. H.; Choi, H. S.; Yatsuka, K.; Masuda, T.; Isojima, S.; Watanabe, M.; Suzawa, C.; Koo, J. Y.

    2007-10-01

    A new 100 m underground HTS cable system was planned for an experimental study in a real scale. The main targets of the project were the verification of the system application. Various types and multipoint analogue data including digital control sequence data were required to be measured. Because of the long operating period of the system cooling and warming sequence, very high operating stability was required. Additionally the economically designed main cooling facility was requested over-night manual operation. The basic function of the data acquisition and control system was the gathering of various type data and the control of test facilities include the cooling facility. Most effort of the design procedure was focused on making the automatic operation including under an emergency situation and the alerting of the emergency state to the operators staying even remote place. The main focus of this function was reducing of the operating man power, specially requested for over-night. So various emergency situations and scenarios were considered and analyzed for the automation operation.

  15. A two-dimensional finite element method to calculate the AC loss in superconducting cables, wires and coated conductors

    In order to utilize HTS conductors in AC electrical devices, it is very important to be able to understand the characteristics of HTS materials in the AC electromagnetic conditions and give an accurate estimate of the AC loss. A numerical method is proposed in this paper to estimate the AC loss in superconducting conductors including MgB2 wires and YBCO coated conductors. This method is based on solving a set of partial differential equations in which the magnetic field is used as the state variable to get the current and electric field distributions in the cross sections of the conductors and hence the AC loss can be calculated. This method is used to model a single-element and a multi-element MgB2 wires. The results demonstrate that the multi-element MgB2 wire has a lower AC loss than a single-element one when carrying the same current. The model is also used to simulate YBCO coated conductors by simplifying the superconducting thin tape into a one-dimensional region where the thickness of the coated conductor can be ignored. The results show a good agreement with the measurement

  16. A two-dimensional finite element method to calculate the AC loss in superconducting cables, wires and coated conductors

    Hong, Z; Jiang, Y; Pei, R; Coombs, T A [Electronic, Power and Energy Conversion Group, Engineering Department, University of Cambridge, CB2 1PZ (United Kingdom); Ye, L [Department of Electrical Power Engineering, CAU, P. O. Box 210, Beijing 100083 (China); Campbell, A M [Interdisciplinary Research Centre in Superconductivity, University of Cambridge, CB3 0HE (United Kingdom)], E-mail: Zh223@cam.ac.uk

    2008-02-15

    In order to utilize HTS conductors in AC electrical devices, it is very important to be able to understand the characteristics of HTS materials in the AC electromagnetic conditions and give an accurate estimate of the AC loss. A numerical method is proposed in this paper to estimate the AC loss in superconducting conductors including MgB{sub 2} wires and YBCO coated conductors. This method is based on solving a set of partial differential equations in which the magnetic field is used as the state variable to get the current and electric field distributions in the cross sections of the conductors and hence the AC loss can be calculated. This method is used to model a single-element and a multi-element MgB{sub 2} wires. The results demonstrate that the multi-element MgB{sub 2} wire has a lower AC loss than a single-element one when carrying the same current. The model is also used to simulate YBCO coated conductors by simplifying the superconducting thin tape into a one-dimensional region where the thickness of the coated conductor can be ignored. The results show a good agreement with the measurement.

  17. Cable Diagnostic Focused Initiative

    Hartlein, R.A.; Hampton, R.N.

    2010-12-30

    This report summarizes an extensive effort made to understand how to effectively use the various diagnostic technologies to establish the condition of medium voltage underground cable circuits. These circuits make up an extensive portion of the electric delivery infrastructure in the United States. Much of this infrastructure is old and experiencing unacceptable failure rates. By deploying efficient diagnostic testing programs, electric utilities can replace or repair circuits that are about to fail, providing an optimal approach to improving electric system reliability. This is an intrinsically complex topic. Underground cable systems are not homogeneous. Cable circuits often contain multiple branches with different cable designs and a range of insulation materials. In addition, each insulation material ages differently as a function of time, temperature and operating environment. To complicate matters further, there are a wide variety of diagnostic technologies available for assessing the condition of cable circuits with a diversity of claims about the effectiveness of each approach. As a result, the benefits of deploying cable diagnostic testing programs have been difficult to establish, leading many utilities to avoid the their use altogether. This project was designed to help address these issues. The information provided is the result of a collaborative effort between Georgia Tech NEETRAC staff, Georgia Tech academic faculty, electric utility industry participants, as well as cable system diagnostic testing service providers and test equipment providers. Report topics include: •How cable systems age and fail, •The various technologies available for detecting potential failure sites, •The advantages and disadvantages of different diagnostic technologies, •Different approaches for utilities to employ cable system diagnostics. The primary deliverables of this project are this report, a Cable Diagnostic Handbook (a subset of this report) and an online

  18. Low Friction Cryostat for HTS Power Cable of Dutch Project

    Chevtchenko, O.; Zuijderduin, R.; Smit, J.; Willen, D.; Lentge, H.; Thidemann, C.; Traeholt, C.

    2012-01-01

    Particulars of 6 km long HTS AC power cable for Amsterdam project are: a cable has to fit in an annulus of 160 mm, with only two cooling stations at the cable ends [1]. Application of existing solutions for HTS cables would result in excessively high coolant pressure drop in the cable, possibly affe

  19. Effects of Formvar coating and copper-nickel outer sheath on the ac losses of multi-strand subsize cables

    Ac losses of two subcables, one with Formvar coating on the strands of the BNL 12-ml NbTi/Cu/CuNi conductor and another without the coating, were measured using the ANL Subcable Test Facility. The results indicate that couplings among the strands with and without the Formvar coating were quite weak. Weak coupling of the bare strands is due to the high resistance of the copper-nickel outer sheath. In the regime of B(dot) = 0 approx. 1.2 T/s and B = 0 approx. 4 T, the magnetic diffusion time constant was (3.8 - 5.7) x 10-3 s

  20. Switching Overvoltages in 60 kV reactor compensated cable grid due to resonance after disconnection

    Bak, Claus Leth; Baldursson, Haukur; Oumarou, Abdoul M.

    2008-01-01

    Some electrical distribution companies are nowadays replacing overhead lines with underground cables. These changes from overhead to underground cable provoke an increased reactive power production in the grid. To save circuit breakers the reactors needed for compensating this excessive reactive ...

  1. Techniques and equipment for detecting and locating incipient faults in underground power transmission cable systems. Technical progress report 3, 1 July 1979-30 September 1979

    Phillips, A.C.; Nanevicz, J.E.; Adamo, R.C.; Cole, C.A.; Honey, S.K.; Petro, J.P.

    1980-04-01

    The study is divided into seven tasks: (1) developing RF sounding techniques including experimental detector/locator units such as the HV crossmodulation sounder; (2) constructing a prototype swept-frequency cable sounder; (3) measuring cable characteristics; (4) developing power-transmission-line signal couplers; (5) constructing an HV source to augment experimental and prototype detector/locator units; (6) evaluating the prototype swept-frequency cable sounder; and (7) studying technically effective and economical use of incipient-fault detector/locator units.

  2. Underground pipeline corrosion

    Orazem, Mark

    2014-01-01

    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  3. Electromagnetic transients in power cables

    da Silva, Filipe Faria

    2013-01-01

    From the more basic concepts to the most advanced ones where long and laborious simulation models are required, Electromagnetic Transients in Power Cables provides a thorough insight into the study of electromagnetic transients and underground power cables. Explanations and demonstrations of different electromagnetic transient phenomena are provided, from simple lumped-parameter circuits to complex cable-based high voltage networks, as well as instructions on how to model the cables.Supported throughout by illustrations, circuit diagrams and simulation results, each chapter contains exercises,

  4. Gjoea power cable; a green solution

    Dretvik, Svein-Egil

    2010-07-01

    An alternative to today's power generation offshore using either gas or diesel, is alternating current (AC) electric power cable from shore. The power from shore through the AC cable gives high savings for the environment. The cable replaces 4 gas turbines with a total CO2 disposal of 240 00 tonnes each year which represents the disposal of 100 000 cars. ABB was awarded the contract which includes engineering, fabrication and installation of the power cable from Mongstad to the Gjoea platform which will be the longest AC cable in the world with a total length of 100 km. The presentation will include system design, qualification of dynamic power cable, cable fabrication experiences, testing at fabrication yard and installation aspects. (Author)

  5. Strengthening future electricity grid of the Netherlands by integration of HTS transmission cables

    The electricity grid of the Netherlands is changing. There is a call of society to use more underground cables, less overhead lines (OHL) and to reduce magnetic emissions. At the same time, parts of the future transmission grid need strengthening depending on the electricity demand in the coming decades [1]. Novel high temperature superconductor (HTS) AC transmission cables can play a role in strengthening the grid. The advantages as compared to alternatives, are: economic, underground, higher power capacity, lower losses, reduced magnetic field emissions in (existing) OHL, compact: less occupation of land and less permits needed, a possibility to keep 380 kV voltage level in the grid for as long as needed. The main obstacles are: the relatively high price of HTS tapes and insufficient maturity of the HTS cable technology. In the paper we focus on a 34 km long connection in the transmission grid (to be strengthened in three of the four of TenneT scenarios [1]), present the network study results, derive the requirements for corresponding HTS transmission cable system and compare HTS system to the alternatives (OHLs and XLPE cables).

  6. Power applications for superconducting cables

    Tønnesen, Ole; Hansen, Steen; Jørgensen, Preben; Lomholt, Karin; Mikkelsen, Søren D.; Okholm, Jan; Salvin, Sven; Østergaard, Jacob

    2000-01-01

    High temperature superconducting (HTS) cables for use in electric ac power systems are under development around the world today. There are two main constructions under development: the room temperature dielectric design and the cryogenic dielectric design. However, theoretical studies have shown...... that the insertion of these cables in the network is not without problems. The network stability requirements may impose severe constraints on the actual obtainable length of superconducting cables. Load flow considerations show that it may be difficult to use these high current cables to their full...

  7. Techniques and equipment for detecting and locating incipient faults in underground power transmission cable systems. Technical progress report 2, 1 April 1979-30 June 1979

    Phillips, A.C.; Naneviez, J.E.; Adamo, R.C.; Cole, C.A.; Honey, S.K.; Petro, J.P.

    1980-01-01

    The study has been divided into seven tasks: (1) development of RF probing techniques including experimental detector/locator units; (2) construction of a prototype detector/locator unit; (3) measurement of cable characteristics; (4) development of power-transmission-line signal couplers; (5) construction of a high-voltage (HV) source to augment experimental or prototype detector/locator units; (6) evaluation of the prototype detector/locator unit; and (7) study of technically effective and economical use of incipient-fault detector/locator units.

  8. Cable manufacture

    Gamble, P.

    1972-01-01

    A survey is presented of flat electrical cable manufacturing, with particular reference to patented processes. The economics of manufacture based on an analysis of material and operating costs is considered for the various methods. Attention is given to the competitive advantages of the several processes and their resulting products. The historical area of flat cable manufacture is presented to give a frame of reference for the survey.

  9. Switching Restrikes in HVAC Cable Lines and Hybrid HVAC Cable/OHL Lines

    da Silva, Filipe Miguel Faria; Bak, Claus Leth; Balle Holst, Per

    2011-01-01

    The disconnection of HV underground cables may, if unsuccessful, originate a restrike in the circuit breaker, leading to high overvoltages, and potentially damaging the cable and near equipment. Due to the cable high capacitance and low resistance the voltage damping is slow, resulting, half a...... cycle after the disconnection, in a voltage of approximately 2 pu at the circuit breaker terminals. In case of restrike in that instant, it is theoretical possible to attain an overvoltage of 3 pu. The overvoltage can be even larger in hybrid cable-Overhead Lines (OHL), due to voltage magnifications in...

  10. Low Friction Cryostat for HTS Power Cable of Dutch Project

    Chevtchenko, Oleg; Zuijderduin, Roy; Smit, Johan;

    2012-01-01

    affecting public acceptance of the project. In order to solve this problem, a model cryostat was developed consisting of alternating rigid and flexible sections and hydraulic tests were conducted using sub-cooled liquid nitrogen. In the 47 m-long cryostat, containing a full-size HTS cable model, measured......Particulars of 6km long HTS AC power cable for Amsterdam project are: a cable has to fit in an annulus of 160mm, with only two cooling stations at the cable ends [1]. Application of existing solutions for HTS cables would result in excessively high coolant pressure drop in the cable, possibly...

  11. Superconducting power cables in Denmark - a case study

    Østergaard, Jacob

    1997-01-01

    HTS cables will be less expensive for high power ratings, have lower losses for lines with a high load, and have a reduced reactive power production. The use of superconducting cables in Denmark accommodate plans by the Danish utility to make a substantial conversion of overhead lines to underground......A case study of a 450 MVA, 132 kV high temperature superconducting (HTS) power transmission cable has been carried out. In the study, a superconducting cable system is compared to a conventional cable system which is under construction for an actual transmission line in the Danish grid. The study...

  12. Electrohydrodynamic pumping in cable pipes. Final report

    Crowley, J.M.; Chato, J.C.

    1983-02-01

    Many oil-insulated electric power cables are limited by heat buildup caused in part by the low thermal conductivity of the oil. Circulation of the oil is known to reduce the cable temperature, but can lead to excessive pressure buildup on long cables when using conventional pumping methods. An alternate pumping method using distributed electric fields to avoid this pressure buildup is described. Electrohydrodynamic (EHD) pumping was studied both theoretically and experimentally for possible application in underground cable cooling. Theoretical studies included both analytical and finite-element analysis of the flow patterns driven by travelling electric fields. Experimentally, flow rates in a cable-pipe model were measured under a wide variety of operating conditions. Theory and experiment are in agreement for velocities below 10 cm/s, but higher velocities could not be reached in the experiment, due to increased electroconvection and, possibly, turbulence.

  13. Cable Stability

    Bottura, L

    2014-01-01

    Superconductor stability is at the core of the design of any successful cable and magnet application. This chapter reviews the initial understanding of the stability mechanism, and reviews matters of importance for stability such as the nature and magnitude of the perturbation spectrum and the cooling mechanisms. Various stability strategies are studied, providing criteria that depend on the desired design and operating conditions.

  14. On stiffening cables of a long reach manipulator

    A long reach manipulator will be used for waste remediation in large underground storage tanks. The manipulator's slenderness makes it flexible and difficult to control. A low-cost and effective method to enhance the manipulator's stiffness is proposed in this research by using suspension cables. These cables can also be used to accurately measure the position of the manipulator's wrist

  15. Undergrounding issues

    As part of a general review of British Columbia Hydro's rights-of-way policies, a task group was formed to explore and assess the technical, social, environmental, and economic issues related to the provision of suitable underground rights-of-way for distribution and transmission lines. Issues considered were: evaluations of undergrounding; designation of service areas as underground areas; the BC Hydro fund to assist municipalities in beautifying selected areas by placing existing overhead lines underground; community funding of undergrounding; underground options to transmission and distribution requirements; and long-range underground row planning. Key findings are as follows. Undergrounding is technically feasible and available for all BC Hydro operating voltages, but initial construction costs of undergrounding continue to exceed equivalent overhead by a significant margin. Undergrounding can contribute to the optimization of existing rights-of-way. Public safety is improved with undergrounding and long-term benefits to BC Hydro and society are provided by undergrounding, compared to overhead options. Customers have shown some willingness to contribute to the cost of undergrounding, and it is generally agreed that those communities that want undergrounding should pay for it. Policy recommendations are made under each of the issue areas, and justifications for the recommendations are given along with implementation costs and alternative options

  16. Applying Diagnostics to Enhance Cable System Reliability (Cable Diagnostic Focused Initiative, Phase II)

    Hartlein, Rick [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hampton, Nigel [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Perkel, Josh [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hernandez, JC [Univ. de Los Andes, Merida (Venezuela); Elledge, Stacy [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); del Valle, Yamille [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Grimaldo, Jose [Georgia Inst. of Technology, Atlanta, GA (United States). School of Electrical and Computer Engineering; Deku, Kodzo [Georgia Inst. of Technology, Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

    2016-02-01

    The Cable Diagnostic Focused Initiative (CDFI) played a significant and powerful role in clarifying the concerns and understanding the benefits of performing diagnostic tests on underground power cable systems. This project focused on the medium and high voltage cable systems used in utility transmission and distribution (T&D) systems. While many of the analysis techniques and interpretations are applicable to diagnostics and cable systems outside of T&D, areas such as generating stations (nuclear, coal, wind, etc.) and other industrial environments were not the focus. Many large utilities in North America now deploy diagnostics or have changed their diagnostic testing approach as a result of this project. Previous to the CDFI, different diagnostic technology providers individually promoted their approach as the “the best” or “the only” means of detecting cable system defects.

  17. 300 Area signal cable study

    This report was prepared to discuss the alternatives available for removing the 300 Area overhead signal cable system. This system, installed in 1969, has been used for various monitoring and communication signaling needs throughout the 300 Area. Over the years this cabling system has deteriorated, has been continually reconfigured, and has been poorly documented to the point of nonreliability. The first step was to look at the systems utilizing the overhead signal cable that are still required for operation. Of the ten systems that once operated via the signal cable, only five are still required; the civil defense evacuation alarms, the public address (PA) system, the criticality alarms, the Pacific Northwest Laboratory Facilities Management Control System (FMCS), and the 384 annunciator panel. Of these five, the criticality alarms and the FMCS have been dealt with under other proposals. Therefore, this study focused on the alternatives available for the remaining three systems (evacuation alarms, PA system, and 384 panel) plus the accountability aid phones. Once the systems to be discussed were determined, then three alternatives for providing the signaling pathway were examined for each system: (1) re-wire using underground communication ducts, (2) use the Integrated Voice/Data Telecommunications System (IVDTS) already installed and operated by US West, and (3) use radio control. Each alternative was developed with an estimated cost, advantages, and disadvantages. Finally, a recommendation was provided for the best alternative for each system

  18. Design and Evaluation of Ybco Cable for the Albany Hts Cable Project

    Ohya, M.; Yumura, H.; Ashibe, Y.; Ito, H.; Masuda, T.; Sato, K.

    2008-03-01

    The Albany Cable Project's aim is to develop a 350 meter long HTS cable system with a capacity of 800 A at 34.5 kV, located between two substations in the National Grid Power Company's grid. In-grid use of BSCCO HTS cable began on July 20, 2006, and successful long-term operation proceeded as planned. The cable system consists of two cables, one 320 meters long and the other 30 meters, a cable-to-cable splice in a vault, two terminations, and a cooling system. In Phase-II of the Albany project, this autumn, the 30-meter section will be replaced with YBCO cable. The test manufacturing and evaluation of YBCO cable has been carried out using SuperPower's YBCO wires in order to confirm the credibility of the cable design. No degradation of the critical current was found at any stage of manufacture. The fault-current test, involving a 1-meter sample carrying 23 kA at 38 cycles, was conducted under open-bath conditions. The temperature increases at the conductor and shield were comparable to those of the BSCCO core, and no Ic degradation was found after the fault-current test. After the design suitability was confirmed, a 30-meter YBCO cable was manufactured. The critical current of the conductor and the shield were approximately 2.6 kA and 2.4 kA, respectively, almost the same as the design values, considering the wire's Ic and the effect of the magnetic field. The AC loss of the sample cable was 0.34 W/m/phase at 800 Arms and 60 Hz. Following favorable shipping test results, the YBCO cable was shipped to the United States, and arrived at the site in June 2007.

  19. Research and Promotion on the Automatic Roll Line Device of Recycling Communication Cable on the Underground Coal Mine Working Face%煤矿井下工作面回收通讯电缆自动卷线装置的研发和推广

    贾鸿飞

    2015-01-01

    随着科学技术的发展,煤矿的建设也发生了日新月异的变化,当代的现代化煤矿逐步开始进入到数字化矿井的阶段。数字化矿井综采工作面的无线通讯、视频的显示、各个综采设备的运行状态的数据,与地面中心站的网络相连接起来,能实时监视综采工作面的状态,达到了煤矿的安全生产。伴随而来的问题就是综采工作面在回采过程中将回收大量的通讯电缆,其中包括通讯光缆。本实用新型提供的煤矿井下工作面回收通讯电缆自动卷线装置,属于煤矿井下综采工作面设备技术领域,主要解决现有技术人工盘电缆存在着电缆凌乱、摆放不整齐、费时费力、效率低、降低采购成本等诸多问题。本文着重从煤矿井下工作面回收各类通讯电缆自动卷线装置的研发和推广方面进行了相关的阐述与分析。%With the development of science and technology, the construction of coal mine has also changed a lot, the contemporary modernization coal mine gradually begins to enter the stage of digital mine. The connection of wireless communications, video display, running status data of each fully mechanized equipment in the digital coal mine fully mechanized working face with network of the ground central station can achieve real-time monitoring of the state of fully mechanized working face and achieve the coal mine safety production. At the same time, the problems are associated that the fully mechanized working face will recycle a lot of communication cable including communication optical cable in the extraction process. This automatic volume line device of recycling communication cable in the underground coal mine working face provided by this utility model belongs to the equipment technology of underground coal mine fully mechanized working face. It mainly solves the messy cable and auf-stellen, time-consuming, low efficiency, reduce procurement costs and other

  20. Universal Cable Brackets

    Vanvalkenburgh, C.

    1985-01-01

    Concept allows routing easily changed. No custom hardware required in concept. Instead, standard brackets cut to length and installed at selected locations along cable route. If cable route is changed, brackets simply moved to new locations. Concept for "universal" cable brackets make it easy to route electrical cable around and through virtually any structure.

  1. Switching Overvoltages in 60 kV reactor compensated cable grid due to resonance after disconnection

    Bak, Claus Leth; Baldursson, Haukur; Oumarou, Abdoul M.

    2008-01-01

    Some electrical distribution companies are nowadays replacing overhead lines with underground cables. These changes from overhead to underground cable provoke an increased reactive power production in the grid. To save circuit breakers the reactors needed for compensating this excessive reactive...... power could be directly connected to long cables. Switching both cable and reactor together will cause resonance to occur between the cable capacitance and the inductance of the cable during last end disconnection. Similar type of resonance condition is known to have caused switching overvoltages on the...... 400kV grid in Denmark. Therefore it is considered necessary to analyze further whether connecting a reactor directly to 60kV cable can cause switching overvoltages. A model in PSCAD was used to analyze which parameters can cause overvoltage. The switching resonance overvoltage was found to be caused...

  2. Conventional cable testing methods: strengths, weaknesses and possibilities

    The paper reviews the major conventional methods that can be used to test power plant cables. It assesses their usefulness in diagnosing the condition of the insulation of the cable and then proposes some possible directions for innovation. The methods examined are dc insulation resistance measurement, ac signal injection for continuous monitoring and fault location, and the ac measurement of capacitance and loss angle. Specific subjects considered are the effects of temperature, cable construction and installation, and the validity of insulation resistance or loss angle measurement. The innovative proposals refer to the use of automation in the measurement and of computer-based Expert Systems for the evaluation of the results

  3. Parametric study on coupling loss in subsize ITER Nb3Sn cabled specimen

    Nijhuis, Arend; Kate, ten, F.J.W.; Bruzzone, Pierluigi; Bottura, Luca

    1996-01-01

    The cable in conduit conductors for the various ITER coils are required to function under pulse conditions and fields up to 13 T. A parametric study, restricted to a limited variation of the reference cable lay out, is carried out to clarify the quantitative impact of various cable parameters on the coupling loss and to find realistic values for the coupling loss time constants to be used in ac loss computations. The investigations cover ac coupling loss measurements on jacketed sub- and full...

  4. Experimental Investigation of the Corona Discharge in Electrical Transmission due to AC/DC Electric Fields

    Fuangpian Phanupong

    2016-01-01

    Full Text Available Nowadays, using of High Voltage Direct Current (HVDC transmission to maximize the transmission efficiency, bulk power transmission, connection of renewable power source from wind farm to the grid is of prime concern for the utility. However, due to the high electric field stress from Direct Current (DC line, the corona discharge can easily be occurred at the conductor surface leading to transmission loss. Therefore, the polarity effect of DC lines on corona inception and breakdown voltage should be investigated. In this work, the effect of DC polarity and Alternating Current (AC field stress on corona inception voltage and corona discharge is investigated on various test objects, such as High Voltage (HV needle, needle at ground plane, internal defect, surface discharge, underground cable without cable termination, cable termination with simulated defect and bare overhead conductor. The corona discharge is measured by partial discharge measurement device with high-frequency current transformer. Finally, the relationship between supply voltage and discharge intensity on each DC polarity and AC field stress can be successfully determined.

  5. Temperature Dependence of PMD of the Optical Cables

    Ahn, S.J. [Korea Electric Power Research Institute, Taejon (Korea)

    2000-03-01

    This report is relevant to the project {sup K}EPCO All-Optical Network Project{sup w}hich is being carried out by Computer and Communication Group in Power System Laboratory. This report is planned to be used as a reference guide for the PMD strategy of the KEPCO optical networks. The PMD of the optical cable installed in the air as OPGW is greatly affected by the environmental temperature change, unlike that of the optical cable installed underground. The variance was turned out to be 70% larger compared with that of underground optical cable and the time scale of the PMD was less than 5 min, in the worst case. Hence, the compensation technology should be chosen taking into account the properties of the aerial optical cables. (author). 6 refs., 3 figs., 1 tab.

  6. The Mathematical Modelling of Heat Transfer in Electrical Cables

    Bugajev Andrej; Jankevičiūtė Gerda; Tumanova Natalija

    2014-01-01

    This paper describes a mathematical modelling approach for heat transfer calculations in underground high voltage and middle voltage electrical power cables. First of the all typical layout of the cable in the sand or soil is described. Then numerical algorithms are targeted to the two-dimensional mathematical models of transient heat transfer. Finite Volume Method is suggested for calculations. Different strategies of nonorthogonality error elimination are considered. Acute triangles meshes ...

  7. Loss and Inductance Investigation in Superconducting Cable Conductors

    Olsen, Søren Krüger; Tønnesen, Ole; Træholt, Chresten;

    1999-01-01

    the layers are therefore studied theoretically. The current distribution between the superconducting layers is monitored as a function of transport current, and the results are compared with the expected current distribution given by our electrical circuit model.The AC-losses are measured as a...... Hz) the AC-loss was measured on cable #2 to 0.6W/mxphase. This is, to our knowledge, the lowest AC-loss (at 2kA and 77K) of a high temperature superconducting cable conductor reported so far....

  8. UtilityTelecom_CABLE2005

    Vermont Center for Geographic Information — The VT Cable System dataset (CABLE2005) includes lines depicting the extent of Vermont's cable system as of 12/31/2005. Numerous cable companies provide service in...

  9. UtilityTelecom_CABLE2007

    Vermont Center for Geographic Information — The VT Cable System dataset (CABLE2007) includes lines depicting the extent of Vermont's cable system as of 12/31/2007. Numerous cable companies provide service in...

  10. Cable-fault locator

    Cason, R. L.; Mcstay, J. J.; Heymann, A. P., Sr.

    1979-01-01

    Inexpensive system automatically indicates location of short-circuited section of power cable. Monitor does not require that cable be disconnected from its power source or that test signals be applied. Instead, ground-current sensors are installed in manholes or at other selected locations along cable run. When fault occurs, sensors transmit information about fault location to control center. Repair crew can be sent to location and cable can be returned to service with minimum of downtime.

  11. Fault Location on Mixed Overhead Line and Cable Network

    Han, Junyu

    2015-01-01

    Society is increasingly concerned about the environmental impact of energy systems, and prefers to locate power lines underground. In future, certain socially/environmentally sensitive overhead transmission feeders will need to include underground cable sections. Fault location, especially when using travelling waves, become complicated when the combined transmission line includes a number of discontinuities, such as junction points, teed points and fault points. Consequently, a diverse range...

  12. Cable Supported Bridges

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...

  13. Cable Television: Franchising Considerations.

    Baer, Walter S.; And Others

    This volume is a comprehensive reference guide to cable television technology and issues of planning, franchising, and regulating a cable system. It is intended for local government officials and citizens concerned with the development of cable television systems in their communities, as well as for college and university classes in…

  14. Modeling vibration response and damping of cables and cabled structures

    Spak, Kaitlin S.; Agnes, Gregory S.; Inman, Daniel J.

    2015-02-01

    In an effort to model the vibration response of cabled structures, the distributed transfer function method is developed to model cables and a simple cabled structure. The model includes shear effects, tension, and hysteretic damping for modeling of helical stranded cables, and includes a method for modeling cable attachment points using both linear and rotational damping and stiffness. The damped cable model shows agreement with experimental data for four types of stranded cables, and the damped cabled beam model shows agreement with experimental data for the cables attached to a beam structure, as well as improvement over the distributed mass method for cabled structure modeling.

  15. Control of a long reach manipulator with suspension cables for waste storage tank remediation. Final report

    A long reach manipulator will be used for waste remediation in large underground storage tanks. The manipulator's slenderness makes it flexible and difficult to control. A low-cost and effective method to enhance the manipulator's stiffness is proposed in this research by using suspension cables. These cables can also be used to accurately measure the position of the manipulator's wrist

  16. Resistive cryogenic cable, phase III. Final report, April 18, 1974--March 31, 1977

    None

    1977-01-01

    Work performed during 3 years of research on development of a foam-insulated underground cryogenic power transmission cable is reported. Information is included on the cryogenic envelope investigation; evaluation and aging study of electrical insulation; test system specifications; and cable system design and cost studies. (LCL)

  17. Commercialization of Medium Voltage HTS Triax TM Cable Systems

    Knoll, David

    2012-12-31

    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.

  18. SC Power leads and cables - Nominal Current Test Performance of 2 kA-Class High-Tc Superconducting Cable Conductors and Its Implications for Cooling Systems for Utility Cables

    Willen, D. W. A; Daumling, M.; Rasmussen, C. N.; Træholt, Chresten; Olsen, Søren Krüger; Rasmussen, Carsten; Jensen, Kim Høj; Østergaard, Jacob; Kyhle, Anders; Tønnesen, Ole

    The current carrying performance of 3-10 m long superconducting cable conductor models has been evaluated. A reduced energy loss compared to conventional cables can be obtained using high-Tc superconducting materials due to the limited resistive and ac hysteresis losses in some conductor configur...

  19. Interstrand contact resistances of Bi-2212 Rutherford cables for SMES

    Kawagoe, A. [Kagoshima University, Kohrimoto 1-21-40, Kagoshima-shi, Kagoshima 890-0065 (Japan)]. E-mail: kawagoe@eee.kagoshima-u.ac.jp; Kawabata, Y. [Kagoshima University, Kohrimoto 1-21-40, Kagoshima-shi, Kagoshima 890-0065 (Japan); Sumiyoshi, F. [Kagoshima University, Kohrimoto 1-21-40, Kagoshima-shi, Kagoshima 890-0065 (Japan); Nagaya, S. [Chubu Electric Power Co. Inc., Kitazekiyama 20-1, Ohtakacho-aza, Midori-ku, Nagoya 249-8522 (Japan); Hirano, N. [Chubu Electric Power Co. Inc., Kitazekiyama 20-1, Ohtakacho-aza, Midori-ku, Nagoya 249-8522 (Japan)

    2006-10-01

    Interstrand contact resistances of Bi-2212 Rutherford cables for SMES coils were evaluated from a comparison between measured data and 2D-FEM analyses on interstrand coupling losses in these cables. The cables were composed of 30 non-twisted Bi-2212 strands with a diameter of 0.81 mm and a cable twist pitch of 90 mm. Three samples were measured; one of them had NiCr cores and the others had no cores. One of the latter two samples repeatedly experienced bending. The interstrand coupling losses were measured in liquid helium for the straight samples under transverse ac ripple magnetic fields superposed on dc bias magnetic fields. The transverse magnetic field was applied to the samples in directions both perpendicular and parallel to the flat face of the cable. The effect of the bending on the interstrand coupling losses could be neglected for the non-cored samples. The interstrand coupling losses of NiCr cored sample decreased by about 30% compared with the non-cored samples, in case the direction of the transverse magnetic fields applied to the cable is perpendicular to the flat face of the cable. Using these results and 2D-FEM analyses, taking into account that interstrand contact conditions vary from the center to the edge in the cross-section of cables, gave us the conclusion that the between side-by-side strands contact with metallurgical bond only in both edges of the cables.

  20. Underground Mathematics

    Hadlock, Charles R

    2013-01-01

    The movement of groundwater in underground aquifers is an ideal physical example of many important themes in mathematical modeling, ranging from general principles (like Occam's Razor) to specific techniques (such as geometry, linear equations, and the calculus). This article gives a self-contained introduction to groundwater modeling with…

  1. 地下管线对通信电缆的屏蔽效应计算方法%Calculation method of electromagnetic shielding effects of underground pipelines to communication cables

    周宇坤; 马信山

    2001-01-01

    An electromagnetic shielding calculation model of undergroundconductors is presented, which takes the inductive coupling and the resistive coupling into account simultaneously. The traditional electromagnetic shielding calculation method is improved by changing interpolating function with pipeline node currents in place of pipeline element currents. Based on the model, the electromagnetic shielding effectiveness of the buried pipeline to communication cables is calculated and the regularity of electromagnetic shielding effectiveness is discussed. The calculation results show that the dimension of pipeline and grounding resistances will affect shielding effectiveness.%提出了一种同时考虑感性耦合和阻性耦合时的地下管线对通信电缆的电磁屏蔽模型,以管线节点电流代替管线单元电流进行插值,改进了传统电磁屏蔽效应计算方法。在此基础上,进行了地下管线对地下通信电缆的电磁屏蔽系数计算,探讨了屏蔽保护的规律。计算结果表明,管线粗细和端接阻抗将明显影响屏蔽保护效果。

  2. Inductance and current distribution analysis of a prototype HTS cable

    This project is partly supported by NSFC Grant 51207146, RAEng Research Exchange scheme of UK and EPSRC EP/K01496X/1. Superconducting cable is an emerging technology for electricity power transmission. Since the high power capacity HTS transmission cables are manufactured using a multi-layer conductor structure, the current distribution among the multilayer structure would be nonuniform without proper optimization and hence lead to large transmission losses. Therefore a novel optimization method has been developed to achieve evenly distributed current among different layers considering the HTS cable structure parameters: radius, pitch angle and winding direction which determine the self and mutual inductance. A prototype HTS cable has been built using BSCCO tape and tested to validate the design the optimal design method. A superconductor characterization system has been developed using the Labview and NI data acquisition system. It can be used to measure the AC loss and current distribution of short HTS cables.

  3. Dynamic Response Analysis of Towed Cable During Deployment/Retrieval

    WANG Fei; HUANG Guo-liang; DENG De-heng

    2008-01-01

    A numerical approach was developed to analyze the transient behavior of towed cable during ac- tively controlled deployment/retrieval (DR). The cable motion is described by the lumped parameter method, its corresponding boundary conditions are presented. In view of its varying length during DR, two auxiliary arguments are introduced to describe its continuous varying length and discrete number of nodes(equations), the length is determined by the pay out(or reel-in) rate, which is then used to determine the node number by a logic relation. For the discrete mathematical model of towed cable, an algorithm was developed to deal with the discrete governing equations. The simulation results indicate that the cable experiences more com- plex motions due to its varying length, and tension fluctuates seriously in the startup and ending stage of deployment/retrieval. The effect of towing ship's motion in waves on cable during deployment/retrieval is also considered via numerical simulation.

  4. Electrical Aging Phenomena of Power Cables Aged by Switching Impulses

    L.Cao; A.Zanwar; S.Grzybowski

    2013-01-01

    Due to the insufficient information regarding the aging phenomenon of cables caused by switching impulses,we aged 15 kV XLPE and EPR cable samples by 10000 switching impulses in experiments and tested them.Plus in order to compare the aging phenomenon under multi-stress conditions,additional EPR cable samples were aged by rated AC voltage and current with switching impulses superimposed.We used measurements of partial discharge parameters to monitor the cables' conditions during their aging process,and the AC breakdown voltages measurement to evaluate the cables after aging.Moreover,the Fourier transform infrared (FTIR) spectroscopy measurements revealed the changes of insulation materials after aging.The measurement results confirm that the accelerated aging of cable samples had taken place.The impacts of each individual aging factor are shown through the selected measurements and comparison.The study also helps to assess the reliability of the XLPE and EPR cables under similar condition while serving in power systems.

  5. Southwire's High Temperature Superconducting Cable Development - Summary Report

    ORNL for the DC Ic, voltage withstand, ac loss, and other properties using both the Vacuum and Pressure Terminations. The design concept was proven with the 5-m cables and the same design was used for the 30-m cables. Three 30-m cables were constructed during the first two quarters of 1999. The cables were made on flexible formers but they were introduced into three separate rigid vacuum jacketed pipes (VJP). The cables passed the DC Ic tests that were carried out at the manufacturing site. A site was developed at Southwire with a switch yard, liquid nitrogen tank, a cryogenic cooling and delivery system, and a control room with PLC control for the system. The HTS cables were installed by the third quarter of 1999. The HTS cables were energized Jan. 6, 2000. The official opening was carried out on Feb. 18, 2000. As of April 30, 2005 the HTS site has been operating at 100% load for >29,000 hours. Since June 1, 2001 the system has logged over 21,000 hours at full load without an operator on duty at the site. The cryogenic system has been under operation for more than two years and has proven very reliable. Southwire has developed World's First Industrial HTS cable and is continuing to prove its reliability. This report contains several sections outlined below that are related to Southwire's HTS cable development: (1) High Temperature Superconducting (HTS) Tapes; (2) Hand Wound 1-m Cables; (3) Development of Facilities for Construction and testing of HTS cables; (4) 5-m HTS Cables; (5) 30-m HTS Cables, Installation at Southwire; (6) Continued Developments; and (7) Publications. Each of the above sections provide only a short report. The details are given in separate volumes (Vol. 1 to Vol. 7) with separate appendices for each section. These are available at the Cofer Center Technical Library

  6. Rokibaar Underground = Rock bar Underground

    2008-01-01

    Rokibaari Underground (Küütri 7, Tartu) sisekujundus, mis pälvis Eesti Sisearhitektide Liidu 2007. a. eripreemia. Sisearhitekt: Margus Mänd (Tammat OÜ). Margus Männist, tema tähtsamad tööd. Plaan, 5 värv. vaadet, foto M. Männist

  7. Cable fault locator research

    Cole, C. A.; Honey, S. K.; Petro, J. P.; Phillips, A. C.

    1982-07-01

    Cable fault location and the construction of four field test units are discussed. Swept frequency sounding of mine cables with RF signals was the technique most thoroughly investigated. The swept frequency technique is supplemented with a form of moving target indication to provide a method for locating the position of a technician along a cable and relative to a suspected fault. Separate, more limited investigations involved high voltage time domain reflectometry and acoustical probing of mine cables. Particular areas of research included microprocessor-based control of the swept frequency system, a microprocessor based fast Fourier transform for spectral analysis, and RF synthesizers.

  8. Electrical power cable engineering

    Thue, William A

    2011-01-01

    Fully updated, Electrical Power Cable Engineering, Third Edition again concentrates on the remarkably complex design, application, and preparation methods required to terminate and splice cables. This latest addition to the CRC Press Power Engineering series covers cutting-edge methods for design, manufacture, installation, operation, and maintenance of reliable power cable systems. It is based largely on feedback from experienced university lecturers who have taught courses on these very concepts.The book emphasizes methods to optimize vital design and installation of power cables used in the

  9. The US market for high-temperature superconducting wire in transmission cable applications

    Forbes, D

    1996-04-01

    Telephone interviews were conducted with 23 utility engineers concerning the future prospects for high-temperature superconducting (HTS) transmission cables. All have direct responsibility for transmission in their utility, most of them in a management capacity. The engineers represented their utilities as members of the Electric Power Research Institute`s Underground Transmission Task Force (which has since been disbanded). In that capacity, they followed the superconducting transmission cable program and are aware of the cryogenic implications. Nineteen of the 23 engineers stated the market for underground transmission would grow during the next decade. Twelve of those specified an annual growth rate; the average of these responses was 5.6%. Adjusting that figure downward to incorporate the remaining responses, this study assumes an average growth rate of 3.4%. Factors driving the growth rate include the difficulty in securing rights-of-way for overhead lines, new construction techniques that reduce the costs of underground transmission, deregulation, and the possibility that public utility commissions will allow utilities to include overhead costs in their rate base. Utilities have few plans to replace existing cable as preventive maintenance, even though much of the existing cable has exceeded its 40-year lifetime. Ten of the respondents said the availability of a superconducting cable with the same life-cycle costs as a conventional cable and twice the ampacity would induce them to consider retrofits. The respondents said a cable with those characteristics would capture 73% of their cable retrofits.

  10. UtilityTelecom_CABLE2013

    Vermont Center for Geographic Information — The VT Cable dataset (CABLE2013) includes lines depicting the extent of Vermont's cable modem broadband system as of 6/30/2013 in addition to those companies who do...

  11. Cable tracking system proposal

    The Experimental Facilities Division requires a labeling system to identify and catalog the instrumentation, control, and computer cables that will run throughout the building. Tom Sheridan from the MIS Group has already made some general suggestions about the information that could be included in an Oracle-based Cable Tracking System (E-mail text distributed by Gary Gunderson on the 27th of August). Glenn Decker's LS Note No. 191 is also relevant to the subject since it addresses name assignment rules for the storage ring devices. The intent of this note is to recommend a mechanism for tracking wires/cables, with enough specifics, to which all groups in the Division would adhere when pulling cables. Because most cables will run between various beamline devices, hutch safety components, and equipment racks, any method of tracking cables is related to the Equipment Tracking System. That system has been developed by the APS Project personnel and is described in the APS Project Equipment Tracking System Guidelines (DRAFT). It can be adopted to XFD's needs. Two essential features of the Cable Tracking System are: 1) Each cable shell have a unique Identifier, and 2) Cable label must contain information that is helpful during troubleshooting in the field. The Identifier is an alphanumeric string of characters that will originate in the Oraclebased Cable Tracking System. It is not necessary for the identifier to carry a lot of intelligence its primary purpose is simply to provide a link to the database. Bar-coding the Identifier would make it easy to combine cable information with the Equipment Tracking System

  12. COPPER CABLE RECYCLING TECHNOLOGY

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D and D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D and D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D and D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness

  13. Magnetization losses in superconducting YBCO conductor-on-round-core (CORC) cables

    Majoros, M.; Sumption, M. D.; Collings, E. W.; van der Laan, D. C.

    2014-12-01

    Described are the results of magnetization loss measurements made at 77 K on several YBCO conductor-on-round-core (CORC) cables in ac magnetic fields of up to 80 mT in amplitude and frequencies of 50 to 200 Hz, applied perpendicular to the cable axis. The cables contained up to 40 tapes that were wound in as many as 13 layers. Measurements on the cables with different configurations were made as functions of applied ac field amplitude and frequency to determine the effects of their layout on ac loss. In large scale devices such as e.g. Superconducting Magnetic Energy Storage (SMES) magnets, the observed ac losses represent less than 0.1% of their stored energy.

  14. Flux-transfer losses in helically wound superconducting power cables

    Clem, John R; Malozemoff, A P

    2013-06-25

    Minimization of ac losses is essential for economic operation of high-temperature superconductor (HTS) ac power cables. A favorable configuration for the phase conductor of such cables has two counter-wound layers of HTS tape-shaped wires lying next to each other and helically wound around a flexible cylindrical former. However, if magnetic materials such as magnetic substrates of the tapes lie between the two layers, or if the winding pitch angles are not opposite and essentially equal in magnitude to each other, current distributes unequally between the two layers. Then, if at some point in the ac cycle the current of either of the two layers exceeds its critical current, a large ac loss arises from the transfer of flux between the two layers. A detailed review of the formalism, and its application to the case of paramagnetic substrates including the calculation of this flux-transfer loss, is presented.

  15. Test results of a 30-m HTS cable pre-demonstration system in Yokohama project

    High temperature superconducting cable demonstration project supported by Ministry of Economy, Trade and Industry and New Energy and Industrial Technology Development Organization has started since FY 2007 in Japan. Target of this project is to operate a 66 kV, 200 MVA HTS cable in a live grid in order to demonstrate its reliability and stable operation. A demonstration site has been decided to Asahi substation which is located in Yokohama. The cable length will be decided to between 200 and 300 m depending on a site configuration. Various preliminary tests such as critical current, ac losses, fault current loading, mechanical tests, have been conducted by using short core samples in order to confirm a HTS cable design and a cable-to-cable joint structure. From these test results, a HTS cable, a joint and a termination have been designed to meet the required specifications. To verify their performances before the installation of the HTS cable system in Yokohama, a 30-m HTS cable was manufactured and various sample tests were conducted as shipping test. The critical current of the HTS conductor and shield were 6.1 kA and 7.1 kA, respectively. The AC loss was 0.83 W/m/ph at 2 kArms, 60 Hz. As withstand voltage tests, AC 90 kV for 3 h and lightning impulse at ±385 kV were applied to cable core, successfully. These test results has confirmed that the 30-m cable had good properties as designed and satisfied the required specifications. After the success of the shipping tests, the 30-m HTS cable pre-demonstration system has been installed at SEI factory. The cable system will be operated and checked the various performances in this summer.

  16. Test results of a 30-m HTS cable pre-demonstration system in Yokohama project

    Yumura, H.; Ashibe, Y.; Ohya, M.; Itoh, H.; Watanabe, M.; Yatsuka, K.; Masuda, T.; Honjo, S.; Mimura, T.; Kitoh, Y.; Noguchi, Y.

    2010-11-01

    High temperature superconducting cable demonstration project supported by Ministry of Economy, Trade and Industry and New Energy and Industrial Technology Development Organization has started since FY 2007 in Japan. Target of this project is to operate a 66 kV, 200 MVA HTS cable in a live grid in order to demonstrate its reliability and stable operation. A demonstration site has been decided to Asahi substation which is located in Yokohama. The cable length will be decided to between 200 and 300 m depending on a site configuration. Various preliminary tests such as critical current, ac losses, fault current loading, mechanical tests, have been conducted by using short core samples in order to confirm a HTS cable design and a cable-to-cable joint structure. From these test results, a HTS cable, a joint and a termination have been designed to meet the required specifications. To verify their performances before the installation of the HTS cable system in Yokohama, a 30-m HTS cable was manufactured and various sample tests were conducted as shipping test. The critical current of the HTS conductor and shield were 6.1 kA and 7.1 kA, respectively. The AC loss was 0.83 W/m/ph at 2 kA rms, 60 Hz. As withstand voltage tests, AC 90 kV for 3 h and lightning impulse at ±385 kV were applied to cable core, successfully. These test results has confirmed that the 30-m cable had good properties as designed and satisfied the required specifications. After the success of the shipping tests, the 30-m HTS cable pre-demonstration system has been installed at SEI factory. The cable system will be operated and checked the various performances in this summer.

  17. Modeling of a distributed constant electric circuit considering contact resistance and coupling loss analyses for cable twisted at multiple stages

    AC losses in multi-strand superconducting cables, utilized in large-scale applications such as fusion machines, are governed by the contact resistance between strands. Especially, in cable twisted at multiple-stages, a variety of magnetic field diffusion time constants exist and these correspond to the quantity of inter-strand coupling loss in each cabling stage. The rate of magnetic field change is less than several T/s in an average fusion machine. Under this condition, the magnetic field penetrates the cable well and the coupling current circuit with the larger time constant causes larger AC loss. Here, the time constant is equal to the leakage inductance divided by the resistance along the coupling current loop. Therefore, by evaluating the coupling current in the larger loop, which consists of a higher twisting stage (e.g., usually the final cabling stage), the loss in the entire cable can be determined. The leakage inductance between sub-cables can be estimated by considering the electrical centers. On the other hand, inter-sub-cable contact resistance was not previously evaluated due to its complexity. In this study, we established an inter-sub-cable contact resistance model that allows the AC loss in cable with multiple twisting stages to be evaluated numerically. The modeling of contact resistance between sub-cables is discussed in detail. (author)

  18. Grounding Effect on Common Mode Interference of Underground Inverter

    Cheng, Qiang; Cheng, Ning; LI Zhen-shuang

    2013-01-01

    For the neutral point not grounded characteristics of underground power supply system in coal mine, this paper studied common mode equivalent circuit of underground PWM inverter, and extracted parasitic parameters of interference propagation path. The author established a common mode and differential mode model of underground inverter. Taking into account the rise time of PWM, the simulation results of conducted interference by Matlab software is compared with measurement spectrum on the AC s...

  19. High current, low loss high temperature superconductor cables, concepts, properties and applications

    High Temperature Superconductors of the second generation (HTS-2G) became an industrial product during the recent years and are applied in several concepts of high current cables for a variety of applications. Low Losses, a thermal stabilization and mechanical strength are the requested features of the cables. We present an overview on the different cable concepts, their performance and the prospected DC and AC applications. Roebel cables and the CORC cable design are in particular suitable for AC operated high current devices as big generators, motors and large magnets. The performance of such cables was investigated under different conditions, as in pancake coils and layered windings. The behavior of the cables could meanwhile quite well be understood and described by FEM modeling. We also report on advanced cable versions which are equipped with a filamentary structure by means of laser assisted grooving of the superconducting layer. For some applications as large fusion magnets and accelerator magnets, even higher currents are requested. For such purpose Rutherford cables and more sophisticated concepts and cable designs are under investigation. We present the first results on such concepts and discuss the further research to be done. A final general outlook will indicate the prospects for the different applications. (author)

  20. Albany Hts Cable Project Long Term In-Grid Operation Status Update

    Yumura, H.; Masuda, T.; Watanabe, M.; Takigawa, H.; Ashibe, Y.; Ito, H.; Hirose, M.; Sato, K.

    2008-03-01

    High-temperature superconducting (HTS) cable systems are expected to be a solution for improvement of the power grid and three demonstration projects in the real grid are under way in the United States. One of them is the Albany, NY Cable Project, involving the installation and operation of a 350 meter HTS cable system with a capacity of 34.5kV, 800A, connecting between two substations in National Grid's electric utility system. A 320 meter and a 30 meter cable are installed in underground conduit and connected together in a vault. The cables were fabricated with 70km of DI-BSCCO wire in a 3 core-in-one cryostat structure. The cable installation of a 320 meter and a 30 meter section was completed successfully using the same pulling method as a conventional underground cable. After the cable installation, the joint and two terminations were assembled at the Albany site. After the initial cooling of the system, the commissioning tests such as the critical current, heat loss measurement and DC withstand voltage test were conducted successfully. The in-grid operation began on July 20th, 2006 and operated successfully in unattended condition through May 1st, 2007. In the 2nd phase of the Albany project, the 30 meter section is to be replaced by a YBCO cable. The YBCO cable had been developed and a new 30 meter cable was manufactured by using SuperPower's YBCO coated conductors. This paper describes the latest status of the Albany cable project.

  1. Infiniband Based Cable Comparison

    Minich, Makia [ORNL

    2007-07-01

    As Infiniband continues to be more broadly adopted in High Performance Computing (HPC) and datacenter applications, one major challenge still plagues implementation: cabling. With the transition to DDR (double data rate) from SDR (single datarate), currently available Infiniband implementations such as standard CX4/IB4x style copper cables severely constrain system design (10m maximum length for DDR copper cables, thermal management due to poor airflow, etc.). This paper will examine some of the options available and compare performance with the newly released Intel Connects Cables. In addition, we will take a glance at Intel's dual-core and quad-core systems to see if core counts have noticeable effect on expected IO patterns.

  2. Underground logistics

    Foraz, K; CERN. Geneva. TS Department

    2005-01-01

    More than 80’000 tons of materials have to be transported and installed down into the LHC tunnel. The magnet assemblies which represent about 50’000 tons, will be transported according to the master schedule between March 2005 and November 2006. Considering that these about 1’800 cryo-magnets will be transported at a maximum speed of 3 km/h in a narrow tube (where installation works and hardware commissioning activities are ongoing) this duration of 21 months is a real challenge. This paper aims at describing: - the information flows between the different people involved in the logistics attached to the cryo-magnets, - the organization chosen within the Installation Coordination group, - the problems encountered so far and the solutions adopted. The coordination process with other underground transport and activities, mainly for the QRL will also be presented.

  3. Magnet cable manufacturing

    The superconducting magnets used in the construction of particle accelerators are mostly built from flat, multistrand cables with rectangular or keystoned cross sections. The superconducting strands are mostly circular but a design of a cable made of preflattened wires was proposed a few years ago under the name of Berkeley flat; such cable shows some interesting characteristics. Another design consists of a few smaller precabled wires (e.g. 6 around 1). This configuration allows smaller filaments and a better transposition of the current elements. The Superconducting Super Collider project involves the largest amount of superconducting cable ever envisaged for a single machine. Furthermore, the design calls for exceptional accuracy and improved characteristics of the cable. A part of the SSC research and development program is focused on these important questions. In this paper we emphasize the difference between the conventional cabling and wires with superconducting. A new concept for the tooling will be introduced as well as the necessary characteristics of a specialized cabler. 5 figs

  4. A Cool-down and Fault Study of a Long Length HTS Power Transmission Cable

    Yuan, J.; Maguire, J.; Allais, A.; Schmidt, F.

    2006-04-01

    High temperature superconductor (HTS) power transmission cables offer significant advantages in power density over conventional copper-based cables. Currently the US Department of Energy is funding the design, development, and demonstration of the first long length, transmission level voltage, cold dielectric, underground high temperature superconductor power cable. The cable is 620 meters long and is designed for permanent installation in the Long Island Power Authority (LIPA) grid. The cable is specified to carry 574 MVA at a voltage of 138 kV and is designed to withstand a 69 kA fault current for a duration of 200ms. The superconducting state of the cable conductors is maintained by circulating sub-cooled liquid nitrogen, which flows through one phase conductor of the cable and returns through the other two. As HTS cables develop and lengths increase to what may be considered commercial, it is critical to study the cable thermal behavior during cool-down process and fault condition to avoid any possible damage to the cable core due to the thermal stress, over heating or bubble formation. This paper reviews the efforts that have been made to study the cool-down process and fault condition. Descriptions of the transient thermal and fluid model are provided. A discussion of the simulation results is also included.

  5. Report on full-scale horizontal cable tray fire tests, FY 1988

    In recent years, there has been much discussion throughout industry and various governmental and fire protection agencies relative to the flammability and fire propagation characteristics of electrical cables in open cable trays. It has been acknowledged that under actual fire conditions, in the presence of other combustibles, electrical cable insulation can contribute to combustible fire loading and toxicity of smoke generation. Considerable research has been conducted on vertical cable tray fire propagation, mostly under small scale laboratory conditions. In July 1987, the Fermi National Accelerator Laboratory initiated a program of full scale, horizontal cable tray fire tests, in the absence of other building combustible loading, to determine the flammability and rate of horizontal fire propagation in cable tray configurations and cable mixes typical of those existing in underground tunnel enclosures and support buildings at the Laboratory. The series of tests addressed the effects of ventilation rates and cable tray fill, fire fighting techniques, and effectiveness and value of automatic sprinklers, smoke detection and cable coating fire barriers in detecting, controlling or extinguishing a cable tray fire. This report includes a description of the series of fire tests completed in June 1988, as well as conclusions reached from the test results

  6. Free and forced convective cooling of pipe-type electric cables. Volume 1: forced cooling of cables. Final report

    Chato, J.C.; Crowley, J.M.

    1981-05-01

    A multi-faceted research program has been performed to investigate in detail several aspects of free and forced convective cooling of underground electric cable systems. There were two main areas of investigation. The first one reported in this volume dealt with the fluid dynamic and thermal aspects of various components of the cable system. In particular, friction factors for laminar flow in the cable pipes with various configurations were determined using a finite element technique; the temperature distributions and heat transfer in splices were examined using a combined analytical numerical technique; the pressure drop and heat transfer characteristics of cable pipes in the transitional and turbulent flow regime were determined experimentally in a model study; and full-scale model experimental work was carried out to determine the fluid dynamic and thermal characteristics of entrance and exit chambers for the cooling oil. The second major area of activity, reported in volume 2, involved a feasibility study of an electrohydrodynamic pump concept utilizing a traveling electric field generated by a pumping cable. Experimental studies in two different configurations as well as theoretical calculations showed that an electrohydrodynamic pump for the moving of dielectric oil in a cable system is feasible.

  7. Water underground

    de Graaf, Inge

    2015-04-01

    The world's largest assessable source of freshwater is hidden underground, but we do not know what is happening to it yet. In many places of the world groundwater is abstracted at unsustainable rates: more water is used than being recharged, leading to decreasing river discharges and declining groundwater levels. It is predicted that for many regions of the world unsustainable water use will increase, due to increasing human water use under changing climate. It would not be long before shortage causes widespread droughts and the first water war begins. Improving our knowledge about our hidden water is the first step to stop this. The world largest aquifers are mapped, but these maps do not mention how much water they contain or how fast water levels decline. If we can add a third dimension to the aquifer maps, so a thickness, and add geohydrological information we can estimate how much water is stored. Also data on groundwater age and how fast it is refilled is needed to predict the impact of human water use and climate change on the groundwater resource.

  8. Space Charge Accumulation under Effects of Temperature Gradient and Applied Voltage Reversal on Solid Dielectric DC Cable

    Choo, Wilson; Chen, George; Swingler, Steve

    2009-01-01

    A well-known fact of the existence and accumulation of space charge within the insulating material poses threat to the reliability in the operation of dc power cables. When power cables are loaded under high voltage direct current (HVDC), temperature gradient is developed across the insulation. Results of space charge evolution in commercial ac XLPE power cables under an application of 80 kV dc supply at different temperature gradients and during external voltage reversal are discussed in thi...

  9. Analysis of AC loss in superconducting power devices calculated from short sample data

    Rabbers, J.J.; Haken, ten, Bennie; Kate, ten, F.J.W.

    2003-01-01

    A method to calculate the AC loss of superconducting power devices from the measured AC loss of a short sample is developed. In coils and cables the magnetic field varies spatially. The position dependent field vector is calculated assuming a homogeneous current distribution. From this field profile and the transport current, the local AC loss is calculated. Integration over the conductor length yields the AC loss of the device. The total AC loss of the device is split up in different compone...

  10. EHV/HV Underground Cable Systems for Power Transmission

    Bak, Claus Leth

    Power transmission is facing its largest challenges ever with regards to handling a transition from today’s fossil‐based power production into renewable sources of generation. We can no longer place power plants close to centres of consumption; they must be located where the natural resources are...... to be found. One very good example of this is offshore wind power plants. The current transmission system is laid out in a traditional manner, which is based on the idea of not transporting power over longer distances as the power plants have been located near centres of consumption. It has merely...... layout of the transmission system must be re‐thought in order to accommodate the transmission needs for the future. New lines have to be constructed. Transmission lines are usually laid out as overhead lines, which are large structures, i.e. a 400 kV power pylon is 50 meters high. According to public...

  11. Pyrotechnic-actuated cable release

    Hanson, R. W.

    1968-01-01

    Remote, unattended means has been designed and reduced to practice that retains and then releases an attached load by means of a restrained cable. The cable is released by an electrical impulse on signal.

  12. The Electrical Aspects of the choice of Former in a High T-c Superconducting Power Cable

    Däumling, Manfred; Kühle (fratrådt), Anders Van Der Aa; Olsen, Søren Krüger; Træholt, Chresten; Tønnesen, Ole

    1999-01-01

    design of a cable. The diameter of the former determines the overall diameter of the total cable, influences the heat loss to the ambient and enters into the total AC-losses. Depending on whether the former is made of a good or poor electrical conductor eddy currents in the former itself may also...

  13. Improved GPS travelling wave fault locator for power cables by using wavelet analysis

    Zhao, W.; Song, Y.H.; Chen, W.R. [Brunel Univ., Dept. of Electronics and Computer Engineering, Uxbridge (United Kingdom)

    2001-06-01

    The paper propose an improved approach to cable-fault location, which is essentially based on synchronised sampling technique, wavelet analysis and travelling wave principle. After an outline of the new scheme and brief introduction to the three major techniques, wavelet analysis of faulty transient waveforms is conducted in details to determine the best wavelet levels for this particular application. Then a 400 kV underground cable system simulated by the Alternative Transient Program (ATP) under various system and fault conditions is used to fully evaluate the approach. Numerical results show that this scheme is reliable and accurate with errors of less than 2% of the length of the cable line. (Author)

  14. Study on interstrand coupling losses in Rutherford-type superconducting cables

    Two sets of experimental apparatus for measuring the AC losses in superconducting strands and Rutherford-type cable conductors have been constructed. A few strand samples and a number of compacted cable samples with and without a CuMn matrix have been measured. The hysteresis loss, loss from coupling within strands and loss from coupling between strands in cables have been distinguished from each other. The results show that, even for Rutherford cables without any soldering and coating, their AC losses may be quite different from each other due to the variation of the interstrand coupling loss. For cables without a CuMn matrix, interstrand coupling loss increases nearly according to a geometrical series with an increase of curing temperature simulating coil fabrication. However, cables with the CuMn matrix show a relatively small curing temperature dependence. For most of the samples, losses do not show any evident dependence on the mechanical pressure. Interstrand resistances in one of these cables have also been measured; the results indicate that the tendency for a decrease in the interstrand resistances is consistent with the results of AC loss measurements. (author)

  15. Field Demonstration of a 24-kV Superconducting Cable at Detroit Edison

    Kelley, Nathan; Corsaro, Pietro

    2004-12-01

    Customer acceptance of high temperature superconducting (HTS) cable technology requires a substantial field demonstration illustrating both the system's technical capabilities and its suitability for installation and operation within the utility environment. In this project, the world's first underground installation of an HTS cable using existing ductwork, a 120 meter demonstration cable circuit was designed and installed between the 24 kV bus distribution bus and a 120 kV-24 kV transformer at Detroit Edison's Frisbie substation. The system incorporated cables, accessories, a refrigeration system, and control instrumentation. Although the system was never put in operation because of problems with leaks in the cryostat, the project significantly advanced the state-of-the-art in the design and implementation of Warm Dielectric cable systems in substation applications. Lessons learned in this project are already being incorporated in several ongoing demonstration projects.

  16. Design and performance of ultra-high-density optical fiber cable with rollable optical fiber ribbons

    Hogari, Kazuo; Yamada, Yusuke; Toge, Kunihiro

    2010-08-01

    This paper proposes a novel ultra-high-density optical fiber cable that employs rollable optical fiber ribbons. The cable has great advantages in terms of cable weight and diameter, and fiber splicing workability. Moreover, it will be easy to install in a small space in underground ducts and on residential and business premises. The structural design of the rollable optical fiber ribbon is evaluated theoretically and experimentally, and an optimum adhesion pitch P in the longitudinal direction is obtained. In addition, we examined the performance of ultra-high-density cables with a small diameter that employ rollable optical fiber ribbons and bending-loss insensitive optical fibers. The transmission, mechanical and mid-span access performance of these cables was confirmed to be excellent.

  17. Field Demonstration of a 24-kV Superconducting Cable at Detroit Edison

    Customer acceptance of high temperature superconducting (HTS) cable technology requires a substantial field demonstration illustrating both the system's technical capabilities and its suitability for installation and operation within the utility environment. In this project, the world's first underground installation of an HTS cable using existing ductwork, a 120 meter demonstration cable circuit was designed and installed between the 24 kV bus distribution bus and a 120 kV-24 kV transformer at Detroit Edison's Frisbie substation. The system incorporated cables, accessories, a refrigeration system, and control instrumentation. Although the system was never put in operation because of problems with leaks in the cryostat, the project significantly advanced the state-of-the-art in the design and implementation of Warm Dielectric cable systems in substation applications. Lessons learned in this project are already being incorporated in several ongoing demonstration projects

  18. The Danish Superconducting Cable Project

    Tønnesen, Ole

    1997-01-01

    The design and construction of a superconducting cable is described. The cable has a room temperature dielectric design with the cryostat placed inside the electrical insulation.BSCCO 2223 superconducting tapes wound in helix form around a former are used as the cable conductor. Results from...

  19. Cable Television Information.

    New York State Education Dept. , Albany. Bureau of Mass Communications.

    Cable television for the State of New York is discussed in detail with relation to: (1) the regents of the University of the State of New York, (2) legislation, (3) planning and proposals for franchises, (4) the Federal Communications Commission, (5) access rules, (6) a list of companies and those serving schools, and (7) federal/state/local…

  20. Long term investigation of thermal behaviour of 110 kV underground transmission lines in the Belgrade area

    Sredojevic, M.R.; Naumov, R.M.; Popovic, D.P. [Nikola Tesla Electrical Engineering Inst., Belgrade (Yugoslavia); Simic, M.D. [Electrical Utility Co., Belgrade (Yugoslavia)

    1997-12-31

    The paper describes the procedure for applying a special cable backfill material, developed and manufactured at the Institute ``Nikola Tesla`` for the thermal stabilisation and reduction of hot spot cable operating temperature, on specific hot spots of 110 kV underground transmission lines in the Belgrade area. The results presented in this paper are an important contribution to the proof of the justification and necessity of defining and introducing in practice new procedures for the thermal stabilisation and reduction of operating temperature of existing, as well as of new, underground transmission cable lines to be built. (author)

  1. Internal coaxial cable seal system

    Hall, David R.; Sneddon, Cameron; Dahlgren, Scott Steven; Briscoe, Michael A.

    2006-07-25

    The invention is a seal system for a coaxial cable and is placed within the coaxial cable and its constituent components. A series of seal stacks including load ring components and elastomeric rings are placed on load bearing members within the coaxial cable sealing the annular space between the coaxial cable and an electrical contact passing there through. The coaxial cable is disposed within drilling components to transmit electrical signals between drilling components within a drill string. The seal system can be used in a variety of downhole components, such as sections of pipe in a drill string, drill collars, heavy weight drill pipe, and jars.

  2. Long length HTS cable with integrated FCL property

    The past years have shown the growth of bottlenecks in electric power grids, among other reasons caused by the increasing demand of energy in the form of electricity and by the large-scaled integration of renewable sources. As solving of these challenges by means of traditional solutions appears to be more and more problematic, the need for new technology solutions has become apparent. The HTS cable technology demonstrates a great potential in solving of grid congestion issues. In addition to their large power transport capacity and low losses, modern-generation HTS cables also have an integrated fault-current limiting (FCL) property. Applications of such cables in power grids will help to solve fault-current issues when connecting new generators, and dispersed and large-scale renewable sources. As HTS cables, used in current projects, are limited to hundreds of meters in length, they have still not been used for energy transport over long distances. The Dutch DSO Alliander, together with Ultera, is working on the development of a 6 km FCL HTS cable for installation in the Alliander's HV grid. In order to get the low-loss benefits of the HTS technology, a cooling system with a high efficiency is needed. The FCL HTS cable will be cooled by one cooling station at each end of the cable, using a liquid nitrogen coolant. Alliander and Ultera have established and work to achieve technical performance targets believed to be required to realise a 6 km long, 50 kV retrofit system with a power rating of 250 MVA with cooling stations only at the two ends of the cable system. These targets aim to reduce the superconductor's AC loss at a nominal current, reduce the heat leak of the thermally insulating envelope, increase the voltage rating and reduce the friction coefficient of the coolant flow.

  3. Method for analysis the complex grounding cables system

    A new iterative method for the analysis of the performances of the complex grounding systems (GS) in underground cable power networks with coated and/or uncoated metal sheathed cables is proposed in this paper. The analyzed grounding system consists of the grounding grid of a high voltage (HV) supplying transformer station (TS), middle voltage/low voltage (MV/LV) consumer TSs and arbitrary number of power cables, connecting them. The derived method takes into consideration the drops of voltage in the cable sheets and the mutual influence among all earthing electrodes, due to the resistive coupling through the soil. By means of the presented method it is possible to calculate the main grounding system performances, such as earth electrode potentials under short circuit fault to ground conditions, earth fault current distribution in the whole complex grounding system, step and touch voltages in the nearness of the earthing electrodes dissipating the fault current in the earth, impedances (resistances) to ground of all possible fault locations, apparent shield impedances to ground of all power cables, e.t.c. The proposed method is based on the admittance summation method [1] and is appropriately extended, so that it takes into account resistive coupling between the elements that the GS. (Author)

  4. Design and evaluation of 66 kV-class HTS power cable using REBCO wires

    Ohya, M., E-mail: ohya-masayoshi@sei.co.jp [Sumitomo Electric Industries, Ltd., 1-1-3, Shimaya, Konohana-ku, Osaka 554-0024 (Japan); Yumura, H.; Masuda, T. [Sumitomo Electric Industries, Ltd., 1-1-3, Shimaya, Konohana-ku, Osaka 554-0024 (Japan); Amemiya, N. [Kyoto University, Kyoto Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8530 (Japan); Ishiyama, A. [Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Ohkuma, T. [International Superconductivity Technology Center, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan)

    2011-11-15

    A 4-layer cable conductor was manufactured using 4-mm wide REBCO wires with low magnetic textured substrates. The AC loss of the cable conductor was 1.5 W/m at 5 kA. Our cables are expected to achieve the AC loss target of less than 2 W/m/ph at 5 kA. Over-current tests (max. 31.5 kA, 2 s) were conducted for a cable sample and its soundness was verified. A 5 kA-class current lead was also developed. Sumitomo Electric (SEI) has been involved in the development of 66 kV-class HTS cables using REBCO wires. One of the technical targets in this project is to reduce the AC loss to less than 2 W/m/phase at 5 kA. SEI has developed a clad-type of textured metal substrate with lower magnetization loss compared with a conventional NiW substrate. In addition, 30 mm-wide REBCO tapes were slit into 4 mm-wide strips, and these strips were wound spirally on a former with small gaps. The AC loss of a manufactured 4-layer cable conductor was 1.5 W/m at 5 kA at 64 K. Given that the AC loss in a shield layer is supposed to be one-fourth of a whole cable core loss, our cables are expected to achieve the AC loss target of less than 2 W/m/phase at 5 kA. Another important target is to manage a fault current. A cable core was designed and fabricated based on the simulation findings, and over-current tests (max. 31.5 kA, 2 s) were conducted to check its performance. The critical current value of the cable cores were measured before and after the over-current tests and verified its soundness. A 5 kA-class current lead for the cable terminations was also developed. The current loading tests were conducted for the developed current leads. The temperature distribution of the current leads reached to the steady-state within less than 12 h, and it was confirmed that the developed current lead has enough capacity of 5 kA loading.

  5. Design and evaluation of 66 kV-class HTS power cable using REBCO wires

    A 4-layer cable conductor was manufactured using 4-mm wide REBCO wires with low magnetic textured substrates. The AC loss of the cable conductor was 1.5 W/m at 5 kA. Our cables are expected to achieve the AC loss target of less than 2 W/m/ph at 5 kA. Over-current tests (max. 31.5 kA, 2 s) were conducted for a cable sample and its soundness was verified. A 5 kA-class current lead was also developed. Sumitomo Electric (SEI) has been involved in the development of 66 kV-class HTS cables using REBCO wires. One of the technical targets in this project is to reduce the AC loss to less than 2 W/m/phase at 5 kA. SEI has developed a clad-type of textured metal substrate with lower magnetization loss compared with a conventional NiW substrate. In addition, 30 mm-wide REBCO tapes were slit into 4 mm-wide strips, and these strips were wound spirally on a former with small gaps. The AC loss of a manufactured 4-layer cable conductor was 1.5 W/m at 5 kA at 64 K. Given that the AC loss in a shield layer is supposed to be one-fourth of a whole cable core loss, our cables are expected to achieve the AC loss target of less than 2 W/m/phase at 5 kA. Another important target is to manage a fault current. A cable core was designed and fabricated based on the simulation findings, and over-current tests (max. 31.5 kA, 2 s) were conducted to check its performance. The critical current value of the cable cores were measured before and after the over-current tests and verified its soundness. A 5 kA-class current lead for the cable terminations was also developed. The current loading tests were conducted for the developed current leads. The temperature distribution of the current leads reached to the steady-state within less than 12 h, and it was confirmed that the developed current lead has enough capacity of 5 kA loading.

  6. Full-scale horizontal cable-tray tests: Fire-propagation characteristics

    At the Fermi National Accelerator Center (Fermilab), as at any high-energy physics laboratory, the experimental program depends on complex arrays of equipment that require years to assemble and place in service. These equipment arrays are typically located in enclosed tunnels or experimental halls and could be destroyed by rapidly propagating, uncontrolled fire. Cable trays, both vertical and horizontal, are an integral and ubiquitous component of these installations. Concurrently, throughout industry and within the professional fire-fighting community, there has been concern over the flammability and fire propagation characteristics of electrical cables in open cable trays. While some information was available concerning fire propagation in vertical cable trays, little was known about fires in horizontal cable trays. In view of the potential for loss of equipment and facilities, not to mention the programmatic impact of a fire, Fermilab initiated a program of full-scale, horizontal cable-tray fire tests to determine the flammability and rate of horizontal fire propagation in cable-tray configurations and cable mixed typical of those existing in underground tunnel enclosures and support buildings as Fermilab. This series of tests addressed the effects of ventilation rates and cable-tray fill, fire-fighting techniques, and the effectiveness and value of automatic sprinklers, smoke detection, and cable-coating fire barriers in detecting, controlling, or extinguishing a cable-tray fire. Detailed descriptions of each fire test, including sketches of cable-tray configuration and contents, instrumentation, ventilation rates, Fermilab Fire Department personnel observations, photographs, and graphs of thermocouple readings are available in a report of these tests prepared by the Fermilab Safety Section

  7. New Passive Methodology for Power Cable Monitoring and Fault Location

    Kim, Youngdeug

    The utilization of power cables is increasing with the development of renewable energy and the maintenance replacement of old overhead power lines. Therefore, effective monitoring and accurate fault location for power cables are very important for the sake of a stable power supply. The recent technologies for power cable diagnosis and temperature monitoring system are described including their intrinsic limitations for cable health assessment. Power cable fault location methods are reviewed with two main categories: off-line and on-line data based methods. As a diagnostic and fault location approach, a new passive methodology is introduced. This methodology is based on analyzing the resonant frequencies of the transfer function between the input and output of the power cable system. The equivalent pi model is applied to the resonant frequency calculation for the selected underground power cable transmission system. The characteristics of the resonant frequencies are studied by analytical derivations and PSCAD simulations. It is found that the variation of load magnitudes and change of positive power factors (i.e., inductive loads) do not affect resonant frequencies significantly, but there is considerable movement of resonant frequencies under change of negative power factors (i.e., capacitive loads). Power cable fault conditions introduce new resonant frequencies in accordance with fault positions. Similar behaviors of the resonant frequencies are shown in a transformer (TR) connected power cable system with frequency shifts caused by the TR impedance. The resonant frequencies can be extracted by frequency analysis of power signals and the inherent noise in these signals plays a key role to measure the resonant frequencies. Window functions provide an effective tool for improving resonant frequency discernment. The frequency analysis is implemented on noise laden PSCAD simulation signals and it reveals identical resonant frequency characteristics with theoretical

  8. EIGENFREQUENCY ANALYSIS OF CABLE STRUCTURES WITH INCLINED CABLES

    William Paulsen; Greg Slayton

    2006-01-01

    The approximate eigenfrequencies for the in-plane vibrations of a cable structure consisting of inclined cables, together with point masses at various points were computed. It was discovered that the classical transfer matrix method was inadequate for this task, and hence the larger exterior matrices were used to determine the eigenfrequency equation. Then predictions of the dynamics of the general cable structure based on the asymptotic estimates of the exterior matrices were made.

  9. Applied use of combustion turbine generators as a station blackout alternate AC power source

    In response to the 10 CFR 50.63 Station Blackout Rule and NRC Regulatory Guide (RG) 1.155, Arizona Public Service Company (APS) opted to install dual 13.8kV, 3400kW black start combustion turbine generators (CTG's) as an alternate AC (AAC) power source at the Palo Verde Nuclear Generating Station (PVNGS). These CTG's provide AC power to critical plant loads in the event of a Station Blackout (SBO) in any one of the three PVNGS units. The AAC power source entered service in the fall of 1993 for the first PVNGS unit. Connection of the AAC source for the other two nuclear units will be complete by mid-1995. Two redundant CTGs were used to provide assurance that the AAC system availability requirements of RG 1.155 of 95% were met. A CTG site was chosen near an existing source of diesel fuel oil that was reasonably distant from the plant switchyard. The CTG's were installed along with a prefabricated turbine control room (TCR) which houses the CTG control equipment and associated power distribution equipment and battery systems. Cables were routed from the CTG site to each of the PVNGS units utilizing both new and existing underground duct banks. The cables were sized for the combined output of both CTG's at maximum power output for site worst case conditions. At each of the PVNGS units, additional switchgear cubicles were added to provide an interface with the existing plant power distribution system at a point upstream of the safety related power system. A test program was developed by engineering that tested all aspects of the installation and proved its capability to fulfill its purpose. Testing ranged from verifying emergency lighting adequacy to emissions testing and a complete simulation of a SBO. CTG performance was evaluated and verified to meet all expectations

  10. Stray current induced corrosion in lightning rod cables of 525 kV power lines towers: a case study

    Wojcicki, F. R.

    2003-12-01

    Full Text Available With the growth of several areas in modem society, the necessity to generate and carry electrical energy to big cities has greatly increased. Cables supported by power towers with galvanized steel foundation usually carry energy. As the foundations are underground they may cause high rates of corrosion. These are usually detected by a conventional potential measurement using a Cu/CuSO4 reference electrode. It is believed that corrosion results from stray currents that flow through the ground to close the loop between neighboring towers. Stray currents originate in the lightning rod cables of the power line towers, induced by the strong electromagnetic and electric fields of the energized power lines. The intensity and direction of those currents were measured, indicating substantial values of both their AC and DC components. The potential of the tower ground system, measured in the perpendicular direction of the main axis of the power line, was plotted as a function of the distance to the tower base. The results clearly indicated the tendency to corrosive attack in the anodic towers as reflected by the slope of the plot, whereas no signs of corrosion could be found in the reverse slope, confirming the visual inspection of the foundation. The profile of the potential plots could be changed providing the electric insulation of the lightning rod cable.

    Con el crecimiento de varias áreas en la sociedad moderna, la necesidad de generar y conducir la energía eléctrica a las grandes ciudades ha aumentado enormemente. La energía, normalmente, se transporta por cables sostenidos por torres de energía con base de acero galvanizado. Cuando las bases son subterráneas, pueden ocasionar altas tasas de corrosión. Estas, normalmente, se detectan por la medida convencional del potencial empleando un electrodo de referencia de Cu/CuSO4. Se cree que la corrosión es el resultado de corrientes perdidas que fluyen a través de la

  11. Assessment of rock bolt systems for underground waste storage

    A review of existing rock bolting systems was undertaken to assess their suitability in underground design for storage of nuclear waste. Unique engineering considerations are required due to the thermal pulse generated by the waste causing additional stress to the support system and possibly affecting anchorage stability. Field visits were made to four underground projects to assess the performance of a wide variety of rock bolt systems. Cable bolts, point anchor bolts, locally debonded full column cement grout bolts, and yieldable bolt systems show promise. Full scale testing of bolt systems is recommended, together with assessing temperature effects on grout strength and grout longterm stability

  12. Cable networks, services, and management

    2015-01-01

    Cable Networks, Services, and Management is the first book to cover cable networks, services, and their management, in-depth, for network operators, engineers, researchers, and students. Thirteen experts in various fields have contributed their knowledge of network architectures and services, Operations, Administration, Maintenance, Provisioning, Troubleshooting (OAMPT) for residential and business services, cloud, Software Defined Networks (SDN), as well as virtualization concepts and their applications as part of the future directions of cable networks. The book begins by introducing architecture and services for Data Over Cable Service Interface Specification (DOCSIS) 3.0/ 3.1, Converged Cable Access Platform (CCAP), Content Distribution Networks (CDN, IP TV, and Packet Cable and Wi-Fi for Residential Services. Topics that are discussed in proceeding chapters include: operational systems and management architectures, service orders, provisioning, fault manageme t, performance management, billing systems a...

  13. 14 CFR 23.689 - Cable systems.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cable systems. 23.689 Section 23.689... Systems § 23.689 Cable systems. (a) Each cable, cable fitting, turnbuckle, splice, and pulley used must... primary control systems; (2) Each cable system must be designed so that there will be no hazardous...

  14. Current distribution among layers of single phase HTS cable conductor

    Highlights: • A 1.5 m long HTS model cable with 4 layers designed by the uniform current principle has been built. • It is testified that the current distribution is influenced by the proximity effect. • The magnetic flux density and current density have been analyzed. • AC losses of tested current are larger than those of uniform current. - Abstract: High temperature superconducting (HTS) power cable shows high application prospect in modern power transmission, as it is superior over conventional transmission lines in high engineering current density and environmental friendliness. Its configuration is generally composed of several HTS layers designed with the principle of uniform current distribution, but there are few experimental results to verify the distribution. In this paper, a HTS cable model was designed based on the principle of uniform current, and the current distributions among layers in an HTS cable model were measured by Rogowski coils. The results provide an important basis for design of multi-layer HTS cable

  15. Cable Bacteria in Freshwater Sediments

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B.; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the fre...

  16. High-temperature superconducting conductors and cables

    This is the final report of a 3-year LDRD project at LANL. High-temperature superconductivity (HTS) promises more efficient and powerful electrical devices such as motors, generators, and power transmission cables; however this depends on developing HTS conductors that sustain high current densities Jc in high magnetic fields at temperatures near liq. N2's bp. Our early work concentrated on Cu oxides but at present, long wire and tape conductors can be best made from BSCCO compounds with high Jc at low temperatures, but which are degraded severely at temperatures of interest. This problem is associated with thermally activated motion of magnetic flux lines in BSCCO. Reducing these dc losses at higher temperatures will require a high density of microscopic defects that will pin flux lines and inhibit their motion. Recently it was shown that optimum defects can be produced by small tracks formed by passage of energetic heavy ions. Such defects result when Bi is bombarded with high energy protons. The longer range of protons in matter suggests the possibility of application to tape conductors. AC losses are a major limitation in many applications of superconductivity such as power transmission. The improved pinning of flux lines reduces ac losses, but optimization also involves other factors. Measuring and characterizing these losses with respect to material parameters and conductor design is essential to successful development of ac devices

  17. Simplified formulae for the estimation of the positive-sequence resistance and reactance of three-phase cables for different frequencies

    Silva, Filipe Miguel Faria da

    2015-01-01

    The installation of HVAC underground cables became more common in recent years, a trend expected to continue in the future. Underground cables are more complex than overhead lines and the calculation of their resistance and reactance can be challenging and time consuming for frequencies that are...... not power frequency. Software packages capable of performing exact calculations of these two parameters exist, but simple equations able to estimate the reactance and resistance of an underground cable for the frequencies associated to a transient or a resonance phenomenon would be helpful. This paper...... proposes new simplified formulae capable of calculating the positive-sequence resistance and reactance of a cable for frequencies associated to temporary overvoltages, slow-front overvoltages and resonance phenomena. The calculation of a cable’s resistance and reactance is made using a simplified series...

  18. LOCA testing of damaged cables

    Experiments were conducted to assess the effects of dielectric withstand voltage testing of cables and to assess the survivability of aged and damaged cables under loss-of-coolant accident (LOCA) conditions. High potential testing at 240 Vdc/mil on undamaged cables suggested that no damage was incurred on the selected cables. During aging and LOCA testing, Okonite ethylene propylene rubber cables with a bonded jacket experienced unexpected failures. The failures appear to be primarily related to the level of thermal aging. For Brand Rex crosslinked polyolefin cables, the results suggest that 8 mils of insulation remaining should give the cables a high probability of surviving accident exposure following aging. The voltage levels necessary to detect when 8 mils of insulation remain are expected to be roughly 40 kVdc. This voltage level would almost certainly be unacceptable to a utility for use as a damage assessment tool. Although two Rockbestos silicone rubber cables failed during the accident test, the induced wall thickness did not seem to be the major cause of the failures. It appears likely that under less stressful thermal aging conditions, the cables would survive accident testing with as little as 4 mils or less of insulation remaining

  19. Superconducting flat tape cable magnet

    Takayasu, Makoto

    2015-08-11

    A method for winding a coil magnet with the stacked tape cables, and a coil so wound. The winding process is controlled and various shape coils can be wound by twisting about the longitudinal axis of the cable and bending following the easy bend direction during winding, so that sharp local bending can be obtained by adjusting the twist pitch. Stack-tape cable is twisted while being wound, instead of being twisted in a straight configuration and then wound. In certain embodiments, the straight length should be half of the cable twist-pitch or a multiple of it.

  20. Soil scientific supervision of 220/38 kV cable circuits of the power station 'Eemscentrale' in the Dutch province Groningen: Part 2

    Recently, five underground cable circuits were completed at the site of the EPON (an energy utility for the north-eastern part of the Netherlands) title power station, consisting of two 220 kV and two 380 kV connections with a total length of 24 km. In a previous article, attention is paid to theoretical aspects of heat transfer of cables for underground electricity transport, the research method of the soil scientific survey, and the results of the survey for the design of the cable connection, to be made by NKF (cable manufacturer) and for the final execution of the cable design. In this article attention will be paid to soil scientific marginal conditions and soil scientific supervision during the realization. 1 fig., 2 tabs., 2 refs

  1. Cable tray fire tests

    Funds were authorized by the Nuclear Regulatory Commission to provide data needed for confirmation of the suitability of current design standards and regulatory guides for fire protection and control in water reactor power plants. The activities of this program through August 1978 are summarized. A survey of industry to determine current design practices and a screening test to select two cable constructions which were used in small scale and full scale testing are described. Both small and full scale tests to assess the adequacy of fire retardant coatings and full scale tests on fire shields to determine their effectiveness are outlined

  2. Design of Underground Current Detection Nodes Based on ZigBee

    Wei Deyu

    2015-01-01

    Full Text Available At present, most current detection devices of underground power equipment in coal mines of China are equipped with the cable monitoring network. Certain problems such as difficult circuit extension and maintenance exist there. With the help of ZigBee technology, it is able to monitor the underground current of monitoring regions in coal mines safely and effectively. Major advantages include extremely low system cost, safe data transmission, flexible networking and ultra-large network capacity.

  3. Comparison of Bergeron and Frequency-dependent cable models for the simulation of electromagnetic transients

    Silva, Filipe Miguel Faria da

    2016-01-01

    The simulation of electromagnetic transients involving underground cables is very time consuming, when compared with simulations involving overhead lines, and Bergeron models are often used instead of the more accurate frequency-dependent models, in order to reduce the simulation time. This paper...... analyses the simulation errors of different Bergeron models to a reference frequency-dependent model for a 150kV cable. The simulations consider flat and trefoil installation, both-ends bonding and cross-bonding, ideal voltage source and modelling of the area around the cable. The Bergeron model is...... modelling of the area around the cable being energised, the Bergeron model has a small error if tuned for the right frequency....

  4. Risk assessment of 170 kV GIS connected to combined cable/OHL network

    Bak, Claus Leth; Kessel, Jakob; Atlason, Vidir;

    2009-01-01

    This paper concerns different investigations of lightning simulation of a combined 170 kV overhead line/cable connected GIS. This is interesting due to the increasing amount of underground cables and GIS in the Danish transmission system. This creates a different system with respect to lightning...... BFO. Overvoltages are evaluated for varying front times of the lightning surge, different soil resistivities at the surge arrester grounding in the overhead line/cable transition point and a varying length of the connection cable between the transformer and the GIS busbar with a SA implemented...... inadmissible voltages to appear at the transformer. However, BFO caused by a lightning stroke of extremely high magnitude can cause inadmissible voltages to appear at the transformer. With the GIS bus CB in open position results indicate that both SF and BFO can cause inadmissible voltages to appear at the...

  5. Lightning simulation of a combined overhead line/cable connected GIS

    Kessel, Jakob; Atlason, Vioir; Bak, Claus Leth;

    2008-01-01

    The paper concerns different investigations of lightning simulation of a combined 170 kV overhead line/cable connected GIS. This is interesting due to the increasing amount of underground cables and GIS in the Danish transmission system. This creates a different system with respect to lightning...... implementing a simulation model in PSCAD/EMTDC. Simulations are conducted for both SF and BFO where the overvoltage at the transformer are evaluated as this component has the lowest insulation strength. The overvoltages are evaluated for different front imes of the lightning surge, different soil resistivities...... at the surge arrester grounding in the overhead line/cable transition and different length of the connection cable between the transformer and the GIS busbar with a SA implemented. Those simulations are conducted for different positions of the circuit breaker present at the GIS busbar. The lightning...

  6. Blasting in underground mining

    Doneva, Nikolinka; Despodov, Zoran; Mirakovski, Dejan; Hadzi-Nikolova, Marija; Mijalkovski, Stojance

    2015-01-01

    The long history of underground facilities gives us a lot of cognitions that we use in the choice of appropriate drilling and blasting parameters to obtain satisfactory results in underground facility constructions. In this paper are represent parts of those cognitions. Selection of an appropriate blast hole pattern, hole cut type, total quantity of explosives, initiation sequence and to the amount of explosive detonated per delay are crucial for successfully blasting in underground facilitie...

  7. The underground storage

    In this work are given summaries of the addresses presented at the conference on the underground storage of June 2008. The topics described are: 1)sites and legislation of the underground storage in France (Carole Mercier) 2)oil and gas underground storage in salt cavities (Patrick Renoux) 3) geothermal storages (Herve Lesueur) 4)CO2 geological storage in aquifers and exploited oil deposits (Etienne Brosse). (O.M.)

  8. Underground laboratories in Asia

    Deep underground laboratories in Asia have been making huge progress recently because underground sites provide unique opportunities to explore the rare-event phenomena for the study of dark matter searches, neutrino physics and nuclear astrophysics as well as the multi-disciplinary researches based on the low radioactive environments. The status and perspectives of Kamioda underground observatories in Japan, the existing Y2L and the planned CUP in Korea, India-based Neutrino Observatory (INO) in India and China JinPing Underground Laboratory (CJPL) in China will be surveyed

  9. Underground laboratories in Asia

    Lin, Shin Ted, E-mail: linst@mails.phys.sinica.edu.tw [College of Physical Science and Technology, Sichuan University, Chengdu 610064 China (China); Yue, Qian, E-mail: yueq@mail.tsinghua.edu.cn [Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of Engineering Physics, Tsinghua University, Beijing 100084 China (China)

    2015-08-17

    Deep underground laboratories in Asia have been making huge progress recently because underground sites provide unique opportunities to explore the rare-event phenomena for the study of dark matter searches, neutrino physics and nuclear astrophysics as well as the multi-disciplinary researches based on the low radioactive environments. The status and perspectives of Kamioda underground observatories in Japan, the existing Y2L and the planned CUP in Korea, India-based Neutrino Observatory (INO) in India and China JinPing Underground Laboratory (CJPL) in China will be surveyed.

  10. Test results of full-scale high temperature superconductors cable models destined for a 36 kV, 2 kA(rms) utility demonstration

    Daumling, M.; Rasmussen, C.N.; Hansen, F.;

    2001-01-01

    Power cable systems using high temperature superconductors (HTS) are nearing technical feasibility. This presentation summarises the advancements and status of a project aimed at demonstrating a 36 kV, 2 kA(rms) AC cable system by installing a 30 m long full-scale functional model in a power util...

  11. Cable Bacteria in Freshwater Sediments

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus;

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  12. Electromagnetic Transients in Power Cables

    Silva, Filipe Faria Da; Bak, Claus Leth

    For more than a century, overhead lines have been the most commonly used technology for transmitting electrical energy at all voltage levels, especially on the highest levels. However, in recent years, an increase in both the number and length of HVAC cables in the transmission networks...... concerning HVAC cables. An important topic that is not covered in this book is measurements protocols/ methods. The protocols used when performing measurements on a cable depend on what is to be measured, the available equipment and accessibility. Readers interested in the topic are referred to search...... of the method. The chapter continues by analysing the frequency-spectrums of cable-based networks which have lower resonance frequencies than usual because of the larger capacitance of the cables. At the same time, a technique that may help save time when plotting the frequency spectrum of a network is proposed...

  13. Length of a Hanging Cable

    Eric Costello

    2011-01-01

    Full Text Available The shape of a cable hanging under its own weight and uniform horizontal tension between two power poles is a catenary. The catenary is a curve which has an equation defined by a hyperbolic cosine function and a scaling factor. The scaling factor for power cables hanging under their own weight is equal to the horizontal tension on the cable divided by the weight of the cable. Both of these values are unknown for this problem. Newton's method was used to approximate the scaling factor and the arc length function to determine the length of the cable. A script was written using the Python programming language in order to quickly perform several iterations of Newton's method to get a good approximation for the scaling factor.

  14. Numerical Analysis of Heat Transfer and Fluid Characteristics of Flowing Liquid Nitrogen in HTS Cable

    Maruyama, O.; Ohkuma, T.; Izumi, T.; Shiohara, Y.

    High-temperature superconducting (HTS) cable has heat intrusion from the termination including joule heat generation at the terminal joint and from the room temperature cable through the Cu current lead. According to the length of the HTS cable, this heat loss may become a considerable amount which cannot be ignored in the HTS cable system. In this study, referring to a high-voltage cable (HV cable) which was developed in M-PACC project, the effect of heat transfer at the interface between the terminal joint and LN2 in the terminal vessel (ho) on the temperature of the HTS cable were calculated and evaluated. The condition of flow in the terminal vessel was assumed to be natural convection, forced flow or static condition for evaluating this effect with various heat transfer condition. As a result, in the case of the natural convection, most of heats flow into the LN2 in the terminal vessel where the volumetric flow of the LN2 is large since ho becomes high. Accordingly, the temperature rise of the LN2 in the inner pipe of Cu former and the terminal vessel can be restricted. However, in the cases of the forced flow and the static condition, most of heats flow into the LN2 in the inner pipe where the volumetric flow of the LN2 is small since ho becomes small. Accordingly, the temperature rise of the LN2 in the inner pipe becomes high. This temperature rise of the LN2 in the inner pipe makes the temperature of the HTS conductor large resulting in remarkable increase of AC losses. Consequently, on the HV cable design, for restriction of the AC loss increase, it is expected that designing the HTS cable termination such as extending outer surface of the terminal joint for increasing of the heat inflow from the terminal joint to the LN2 in the vessel is effective.

  15. Status and Progress of a Fault Current Limiting Hts Cable to BE Installed in the con EDISON Grid

    Maguire, J.; Folts, D.; Yuan, J.; Henderson, N.; Lindsay, D.; Knoll, D.; Rey, C.; Duckworth, R.; Gouge, M.; Wolff, Z.; Kurtz, S.

    2010-04-01

    In the last decade, significant advances in the performance of second generation (2G) high temperature superconducting wire have made it suitable for commercially viable applications such as electric power cables and fault current limiters. Currently, the U.S. Department of Homeland Security is co-funding the design, development and demonstration of an inherently fault current limiting HTS cable under the Hydra project with American Superconductor and Consolidated Edison. The cable will be approximately 300 m long and is being designed to carry 96 MVA at a distribution level voltage of 13.8 kV. The underground cable will be installed and energized in New York City. The project is led by American Superconductor teamed with Con Edison, Ultera (Southwire and nkt cables joint venture), and Air Liquide. This paper describes the general goals, design criteria, status and progress of the project. Fault current limiting has already been demonstrated in 3 m prototype cables, and test results on a 25 m three-phase cable will be presented. An overview of the concept of a fault current limiting cable and the system advantages of this unique type of cable will be described.

  16. Parametric study on the axial performance of a fully grouted cable bolt with a new pull-out test

    Chen Jianhang⇑; Hagan Paul C.; Saydam Serkan

    2016-01-01

    Modified cable bolts are commonly used in underground mines due to their superior performance in pre-venting bed separation when compared with plain strands. To better test the axial performance of a wide range of cable bolts, a new laboratory short encapsulation pull test (LSEPT) facility was developed. The facility simulates the interaction between cable bolts and surrounding rock mass, using artificial rock cylinders with a diameter of 300 mm in which the cable bolt is grouted. Furthermore, the joint where the load is applied is left unconstrained to allow shear slippage at the cable/grout or grout/rock interface. Based on this apparatus, a series of pull tests were undertaken using the MW9 modified bulb cable bolt. Various parameters including embedment length, test material strength and borehole size were evalu-ated. It was found that within a limited range of 360 mm, there is a linear relationship between the max-imum bearing capacity of the cable bolt and embedment length. Beyond 360 mm, the peak capacity continues to rise but with a much lower slope. When the MW9 cable bolt was grouted in a weak test material, failure always took place along the grout/rock interface. Interestingly, increasing the borehole diameter from 42 to 52 m in weak test material altered the failure mode from grout/rock interface to cable/grout interface and improved the performance in terms of both peak and residual capacity.

  17. 400 MW grid connection to the Anholt offshore wind farm in a single 220 kV cable system

    Kvarts, Thomas [Energinet.dk (Denmark); Bailleul, March; Douima, Youssef; Petitot, Francois [General Cable Group, Silec, Cachan (France); Domingo, Jose M. [General Cable Group (Spain); Jensen, Anders; Salwin, Sven T. [nkt cables (Denmark)

    2011-07-01

    In 2012, the so far largest wind farm in Denmark, Anholt offshore wind farm, will bring 400 MW more electrical power to Denmark. To that effect, Energinet.dk, Denmark's transmission system operator, will install and operate an 85-km-long grid connection from the Anholt platform to the Danish electricity transmission grid. This connection is composed of: (1) a single 24 km 245 kV submarine, 3 core cable, delivered and installed by nkt cables, and (2) a 60 km 245 kV underground cable system, delivered by the General Cable group. (3) an offshore transformer platform. (4) reactive compensation and transformation onshore. This aim of this paper is to present the characteristics of this project, the first at 245 kV in Denmark, and one of the first 245 kV 3 core submarine cables worldwide. We will first discuss the reasons that prevailed in defining the link's design: routes, voltage, cables dimensioning, impact of capitalized losses etc. Then, the submarine and underground cable systems' characteristics and necessary type test are presented. Finally, we present an overview of the actual implementation of each solution. (orig.)

  18. Roebel cables from REBCO coated conductors: a one-century-old concept for the superconductivity of the future

    Energy applications employing high-temperature superconductors (HTS), such as motors/generators, transformers, transmission lines and fault current limiters, are usually operated in the alternate current (ac) regime. In order to be efficient, the HTS devices need to have a sufficiently low value of ac loss, in addition to the necessary current-carrying capacity. Most applications are operated with currents beyond the current capacity of single conductors and consequently require cabled conductor solutions with much higher current carrying capacity, from a few kA up to 20–30 kA for large hydro-generators. A century ago, in 1914, Ludwig Roebel invented a low-loss cable design for copper cables, which was successively named after him. The main idea behind Roebel cables is to separate the current in different strands and to provide a full transposition of the strands along the cable direction. Nowadays, these cables are commonly used in the stator of large generators. Based on the same design concept of their conventional material counterparts, HTS Roebel cables from REBCO coated conductors were first manufactured at the Karlsruhe Institute of Technology and have been successively developed in a number of varieties that provide all the required technical features such as fully transposed strands, high transport currents and low ac losses, yet retaining enough flexibility for a specific cable design. In the past few years a large number of scientific papers have been published on the concept, manufacturing and characterization of such cables. Therefore it is timely for a review of those results. The goal is to provide an overview and a succinct and easy-to-consult guide for users, developers, and manufacturers of this kind of HTS cable. (topical review)

  19. Roebel cables from REBCO coated conductors: a one-century-old concept for the superconductivity of the future

    Goldacker, Wilfried; Grilli, Francesco; Pardo, Enric; Kario, Anna; Schlachter, Sonja I.; Vojenčiak, Michal

    2014-09-01

    Energy applications employing high-temperature superconductors (HTS), such as motors/generators, transformers, transmission lines and fault current limiters, are usually operated in the alternate current (ac) regime. In order to be efficient, the HTS devices need to have a sufficiently low value of ac loss, in addition to the necessary current-carrying capacity. Most applications are operated with currents beyond the current capacity of single conductors and consequently require cabled conductor solutions with much higher current carrying capacity, from a few kA up to 20-30 kA for large hydro-generators. A century ago, in 1914, Ludwig Roebel invented a low-loss cable design for copper cables, which was successively named after him. The main idea behind Roebel cables is to separate the current in different strands and to provide a full transposition of the strands along the cable direction. Nowadays, these cables are commonly used in the stator of large generators. Based on the same design concept of their conventional material counterparts, HTS Roebel cables from REBCO coated conductors were first manufactured at the Karlsruhe Institute of Technology and have been successively developed in a number of varieties that provide all the required technical features such as fully transposed strands, high transport currents and low ac losses, yet retaining enough flexibility for a specific cable design. In the past few years a large number of scientific papers have been published on the concept, manufacturing and characterization of such cables. Therefore it is timely for a review of those results. The goal is to provide an overview and a succinct and easy-to-consult guide for users, developers, and manufacturers of this kind of HTS cable.

  20. HAWAII UNDERGROUND STORAGE TANKS

    This is a point coverage of underground storage tanks(UST) for the state of Hawaii. The original database was developed and is maintained by the State of Hawaii, Dept. of Health. The point locations represent facilities where one or more underground storage tanks occur. Each fa...

  1. Cable Aerodynamic Control

    Kleissl, Kenneth

    categorization of the different control technics together with an identification of two key mechanisms for reduction of the design drag force. During this project extensive experimental work examining the aerodynamics of the currently used cable surface modifications together with new innovative proposals have...... drag force due to the high intensity of streamwise vorticity, whereas the helical fillets resulted in a more gradual flow transition because of the spanwise variation. During yawed flow conditions, the asymmetrical appearance of the helical solution was found to induce a significant lift force with a...... were tested. While a proper discrete helical arrangement of Cylindrical Vortex Generators resulted in a superior drag performance, only systems applying "mini-strakes" were capable of complete rivulet suppression. When the strakes was positioned in a staggered helical arrangement, the innovative system...

  2. Cable Bacteria in Freshwater Sediments.

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-09-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  3. Recent development of an HTS power cable using YBCO tapes

    Overcurrent characteristics and reduction of AC loss are essential for high temperature superconducting (HTS) cable in a real grid. AC loss in an HTS conductor using YBCO could be potentially small but protection for overcurrent was needed. A 0.1 mm thick copper tape soldered to the YBCO tape was effective as protection from overcurrent and did not affect the increase in AC loss. The 2 m HTS conductor with Cu strands of 250 mm2 and YBCO tapes with copper was fabricated. This conductor could withstand overcurrent of 31.5 kA for 2 s. To reduce AC loss, 10 mm wide YBCO tapes were divided into five strips using YAG laser. Using narrower strips and decreasing the space between the strips were effective in reducing AC loss. In consideration of this configuration, a three-layer conductor was fabricated, and AC loss of 0.054 W/m at 1 kA rms was achieved even though it had a small outer diameter of 19.6 mm

  4. Investigation of mechanism of breakdown in XLPE cables. Final report

    McKean, A.L.

    1976-07-01

    The basic hypothesis that microporosity plays a significant role in the mechanism of breakdown of XLPE cable is explored. The potential improvement achieved by impregnating the microporous regions of the cable core with a neutral liquid is evaluated, with relation to ac voltage life and impulse strength. The effect at higher frequency is also demonstrated. A similar test program is pursued on model cables, designed to explore the effects of gas pressure and gas type on breakdown and life, since it is reasonable to expect that only the microporous regions of the insulation should be sensitive to the gas-pressure environment. Comparison of gas-pressurized model breakdown stress (and related microvoid size) with basic Paschen curves demonstrates reasonably good agreement, indicating that partial discharge is the basic mechanism of fatigue and breakdown. The form of the voltage life curve above and below the discharge inception level is proposed, and evidence is presented indicating breakdown originates in the bulk insulation as well as at the shield interface. It is also shown that model cable discharge energies are below 0.1 pC, even at very high stress, and cannot be measured with modern detectors. Results with liquid or gas impregnation suggest a possible approach to dielectric improvement.

  5. Magnetization Losses of Roebel Cable Samples with 2G YBCO Coated Conductor Strands

    Yang, Y.; Falorio, I.; Young, E.A.; Kario, A.; Goldacker, W.; Dhallé, M. M. J.; van Nugteren, J.; Kirby, G.; Bottura, L.; Ballarino, A.; 10.1109/TASC.2016.2525926

    2016-01-01

    Roebel cable with 2G YBCO strands is one of the promising HTS solutions of fully transposed high current conductors for high field accelerator magnets. Following the considerable research effort on the manufacturing of Roebel cables in recent years, sample conductors are now available in useful lengths with reproducible performances to allow detailed characterizations beyond the standard critical current measurements. The ac loss and strands coupling are of significant interest for the field quality of the accelerator magnets. We report a set of systematic ac loss measurements on two different Roebel cable samples prepared for the EuCARD2 collaboration. The measurements were performed over a wide range of temperature between 5 K and 90 K and the results were analyzed in the context of strands architecture and coupling. The results show that the transposed bundles are partially decoupled and the strands in transposition sections behave as an isolated single tape if the strands are insulated.

  6. A full 3D time-dependent electromagnetic model for Roebel cables

    Rodriguez Zermeno, Victor Manuel; Grilli, Francesco; Sirois, Frederic

    2013-01-01

    High temperature superconductor Roebel cables are well known for their large current capacity and low AC losses. For this reason they have become attractive candidates for many power applications. The continuous transposition of their strands reduces the coupling losses while ensuring better curr...

  7. Analysis of AC loss in superconducting power devices calculated from short sample data

    Rabbers, J.J.; Haken, ten B.; Kate, ten H.H.J.

    2003-01-01

    A method to calculate the AC loss of superconducting power devices from the measured AC loss of a short sample is developed. In coils and cables the magnetic field varies spatially. The position dependent field vector is calculated assuming a homogeneous current distribution. From this field profile

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

    Litzenberger, Wayne; Lava, Val

    1994-08-01

    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).

  9. 一体式电缆井的使用%Use of Integrated Cable Pit

    蒋彦; 韦玮; 谈东波

    2012-01-01

    通过分析现有室外电缆井施工存在的不足,提出预制一体式电缆井的解决方案。分析一体式电缆井的技术优势、施工方法和注意事项,说明一体式电缆井的可实施性和推广价值。%Ac cording to the analysis on the disadvantages of construction of existing outdoor cable pits, a solution for prefabricated integrated cable pits is proposed. The technical advantages, construction methods and precautions of integrated cable pits are analyzed, and the practicality and promotion value of integrated cable pits is explained

  10. On the cable expansion formula

    Liu, Qihou

    2008-01-01

    In this paper, a generalized version of Morton's formula is proved. Using this formula, one can write down the colored Jones polynomials of cabling of an knot in terms of the colored Jones polynomials of the original knot.

  11. Static and Dynamic Characteristics of a Long-Span Cable-Stayed Bridge with CFRP Cables

    Xu Xie

    2014-06-01

    Full Text Available In this study, the scope of CFRP cables in cable-stayed bridges is studied by establishing a numerical model of a 1400-m span of the same. The mechanical properties and characteristics of CFRP stay cables and of a cable-stayed bridge with CFRP cables are here subjected to comprehensive analysis. The anomalies in the damping properties of free vibration, nonlinear parametric vibration and wind fluctuating vibration between steel cables and CFRP cables are determined. The structural stiffness, wind resistance and traffic vibration of the cable-stayed bridge with CFRP cables are also analyzed. It was found that the static performances of a cable-stayed bridge with CFRP cables and steel cables are basically the same. The natural frequencies of CFRP cables do not coincide with the major natural frequencies of the cable-stayed bridge, so the likelihood of CFRP cable-bridge coupling vibration is minuscule. For CFRP cables, the response amplitudes of both parametric vibration and wind fluctuating vibration are smaller than those of steel cables. It can be concluded from the research that the use of CFRP cables does not change the dynamic characteristics of the vehicle-bridge coupling vibration. Therefore, they can be used in long-span cable-stayed bridges with an excellent mechanical performance.

  12. Alternating current losses of a 10 metre long low loss superconducting cable conductor determined from phase sensitive measurements

    Olsen, Søren Krüger; Kühle (fratrådt), Anders Van Der Aa; Træholt, Chresten;

    1999-01-01

    The ac loss of a superconducting cable conductor carrying an ac current is small. Therefore the ratio between the inductive (out-of-phase) and the resistive (in-phase) voltages over the conductor is correspondingly high. In vectorial representations this results in phase angles between the current...... and the voltage over the cable close to 90 degrees. This has the effect that the loss cannot be derived directly using most commercial lock-in amplifiers due to their limited absolute accuracy. However, by using two lock-in amplifiers and an appropriate correction scheme the high relative accuracy of...... such lock-in amplifiers can be exploited. In this paper we present the results from ac-loss measurements on a low loss 10 metre long high temperature superconducting cable conductor using such a correction scheme. Measurements were carried out with and without a compensation circuit that could reduce...

  13. The underground macroeconomics

    Marin Dinu

    2013-01-01

    Full Text Available Like Physics, which cannot yet explain 96% of the substance in the Universe, so is Economics, unprepared to understand and to offer a rational explicative model to the underground economy.

  14. Orpheus in the Underground

    Puskás Dániel

    2015-12-01

    Full Text Available In my study I deal with descents to the underworld and hell in literature in the 20th century and in contemporary literature. I will focus on modem literary reinterpretations of the myth of Orpheus, starting with Rilke’s Orpheus. Eurydice. Hermes. In Seamus Heaney’s The Underground. in the Hungarian Istvan Baka’s Descending to the Underground of Moscow and in Czesław Miłosz’s Orpheus and Eurydice underworld appears as underground, similarly to the contemporary Hungarian János Térey’s play entitled Jeramiah. where underground will also be a metaphorical underworld which is populated with the ghosts of the famous deceased people of Debrecen, and finally, in Péter Kárpáti’s Everywoman the grave of the final scene of the medieval Everyman will be replaced with a contemporary underground station. I analyse how an underground station could be parallel with the underworld and I deal with the role of musicality and sounds in the literary works based on the myth of Orpheus.

  15. Parametric Vibration and Vibration Reduction of Cables in Cable-stayed Space Latticed Structure

    BAO Yan; ZHOU Dai; LIU Jie

    2008-01-01

    Mechanical model and vibration equation of a cable in cable-stayed sparse latticed structure (CSLS) under external axial excitation were founded. Determination of the mass lumps and natural frequencies supplied by the space latticed structure (SLS) was analyzed. Multiple scales method (MSM) was introduced to analyze the characteristics of cable's parametric vibration, and the precise time-integration method (PTIM) was used to solve vibration equation. The vibration behavior of a cable is closely relative to the frequency ratio of the cable and SLS. The cable's parametric vibration caused by the external axial excitation easily occurs if the frequency ratio of the cable and SLS is in a certain range, and the cable's vibration amplitude varies greatly even if the initial disturbance supplied by SLS changes a little. Furthermore, the mechanical model and vibration equation of the composite cable system consisting of main cables and assistant cables were studied. The parametric analysis such as the pre-tension level and arrangement of the assistant cables was carried out. Due to the assistant cables, the single-cable vibration mode can be transferred to the global vibration mode, and the stiffness and damping of the cable system are enhanced. The natural frequencies of the composite cable system with the curve line arrangement of assistant cables are higher than those with the straight-line arrangement and the former is more effective than the latter on the cable's vibration suppression.

  16. Flat conductor cable design, manufacture, and installation

    Angele, W.; Hankins, J. D.

    1973-01-01

    Pertinent information for hardware selection, design, manufacture, and quality control necessary for flat conductor cable interconnecting harness application is presented. Comparisons are made between round wire cable and flat conductor cable. The flat conductor cable interconnecting harness systems show major cost, weight, and space savings, plus increased system performance and reliability. The design application section includes electrical characteristics, harness design and development, and a full treatise on EMC considerations. Manufacturing and quality control sections pertain primarily to the developed conductor-contact connector system and special flat conductor cable to round wire cable transitions.

  17. Optical Measurement of Cable and String Vibration

    Y. Achkire

    1998-01-01

    Full Text Available This paper describes a non contacting measurement technique for the transverse vibration of small cables and strings using an analog position sensing detector. On the one hand, the sensor is used to monitor the cable vibrations of a small scale mock-up of a cable structure in order to validate the nonlinear cable dynamics model. On the other hand, the optical sensor is used to evaluate the performance of an active tendon control algorithm with guaranteed stability properties. It is demonstrated experimentally, that a force feedback control law based on a collocated force sensor measuring the tension in the cable is feasible and provides active damping in the cable.

  18. Numerical estimation of AC loss in superconductors with ripple current

    Highlights: •The loss energy density with ripple current is numerically calculated. •Irie–Yamafuji model is used for magnetic field dependence of critical current. •Calculated result of cylindrical superconductor agrees with theoretical result. •AC loss of strip superconductor becomes large at small ripple current amplitude. •Strip superconductor should be used as a form of hollow cylinder to reduce AC loss. -- Abstract: The loss energy density (AC loss) with ripple current is numerically calculated by finite element method for cylindrical and strip superconductors based on Irie–Yamafuji model in which the magnetic field dependence of the critical current density is taken into account for design of DC transmission cable system. It is confirmed that calculated result of the AC loss in the cylindrical superconductor with the ripple current agrees well with theoretical estimation which was reported in the previous work. On the contrary, the AC loss in the strip superconductor with the ripple current is obtained only by numerical calculation. It is found that the AC loss in the strip superconductor of the ripple current becomes larger than that without DC current at small ripple current amplitude, since the penetration depth of magnetic field becomes large. Therefore, it is recommended that strip superconductor is better to use as cylindrical hollow superconductor for DC transmission cable system to reduce the AC loss

  19. The data quality monitoring system of non-cable self-positioning seismographs

    Zheng, F.; Lin, J.; Linhang, Z.; Hongyuan, Y.; Zubin, C.; Huaizhu, Z.; Sun, F.

    2013-12-01

    Seismic exploration is the most effective and promising geophysical exploration methods, it inverts underground geological structure by recording crust vibration caused by nature or artificial means. In order to get rid of the long-term dependence on imported seismographs, China pays more and more attention to the independent research and development of seismic exploration equipment. This study is based on the self-invented non-cable self-positioning seismographs of Jilin University. Non-cable seismographs have many advantages such as simple arrangement, light, easy to move, easy to maintain, low price, large storage space and high-quality data, they especially apply to complex terrain and field construction environment inconvenient laying big lines. The built-in integration of GPS realizes precise clock synchronization, fast and accurate self-positioning for non-cable seismographs. The low power design and the combination of built-in rechargeable battery and external power can effectively improve non-cable seismographs` working time, which ensures the stability of exploration and construction. In order to solve the problem that the non-cable seismographs are difficult to on-site data monitor and also to provide non-cable seismographs` ability of real-time data transmission, We integrate the wireless communication technology into non-cable seismographs, combing instrument, electronic, communication, computer and many other subject knowledge, design and develop seismic exploration field work control system and seismic data management system. Achieve two research objectives which are real-time data quality monitoring in the resource exploration field and status monitoring of large trace spacing long-term observations for seismographs. Through several field experiments in different regions, we accumulate a wealth of experience, and the experiments effectively prove the good practical performance of non-cable self-positioning seismographs and data quality monitoring

  20. Underground physics with DUNE

    Kudryavtsev, Vitaly A.; DUNE Collaboration

    2016-05-01

    The Deep Underground Neutrino Experiment (DUNE) is a project to design, construct and operate a next-generation long-baseline neutrino detector with a liquid argon (LAr) target capable also of searching for proton decay and supernova neutrinos. It is a merger of previous efforts of the LBNE and LBNO collaborations, as well as other interested parties to pursue a broad programme with a staged 40-kt LAr detector at the Sanford Underground Research Facility (SURF) 1300 km from Fermilab. This programme includes studies of neutrino oscillations with a powerful neutrino beam from Fermilab, as well as proton decay and supernova neutrino burst searches. In this paper we will focus on the underground physics with DUNE.

  1. Underground mineral extraction

    Miller, C. G.; Stephens, J. B.

    1980-01-01

    A method was developed for extracting underground minerals such as coal, which avoids the need for sending personnel underground and which enables the mining of steeply pitched seams of the mineral. The method includes the use of a narrow vehicle which moves underground along the mineral seam and which is connected by pipes or hoses to water pumps at the surface of the Earth. The vehicle hydraulically drills pilot holes during its entrances into the seam, and then directs sideward jets at the seam during its withdrawal from each pilot hole to comminute the mineral surrounding the pilot hole and combine it with water into a slurry, so that the slurried mineral can flow to a location where a pump raises the slurry to the surface.

  2. Underground physics with DUNE

    Kudryavtsev, Vitaly A

    2016-01-01

    The Deep Underground Neutrino Experiment (DUNE) is a project to design, construct and operate a next-generation long-baseline neutrino detector with a liquid argon (LAr) target capable also of searching for proton decay and supernova neutrinos. It is a merger of previous efforts of the LBNE and LBNO collaborations, as well as other interested parties to pursue a broad programme with a staged 40 kt LAr detector at the Sanford Underground Research Facility (SURF) 1300 km from Fermilab. This programme includes studies of neutrino oscillations with a powerful neutrino beam from Fermilab, as well as proton decay and supernova neutrino burst searches. In this paper we will focus on the underground physics with DUNE.

  3. Underground Physics with DUNE

    Kudryavtsev, Vitaly A. [Sheffield U.

    2016-01-14

    The Deep Underground Neutrino Experiment (DUNE) is a project to design, construct and operate a next-generation long-baseline neutrino detector with a liquid argon (LAr) target capable also of searching for proton decay and supernova neutrinos. It is a merger of previous efforts of the LBNE and LBNO collaborations, as well as other interested parties to pursue a broad programme with a staged 40 kt LAr detector at the Sanford Underground Research Facility (SURF) 1300 km from Fermilab. This programme includes studies of neutrino oscillations with a powerful neutrino beam from Fermilab, as well as proton decay and supernova neutrino burst searches. In this paper we will focus on the underground physics with DUNE.

  4. Online Cable Tester and Rerouter

    Lewis, Mark; Medelius, Pedro

    2012-01-01

    Hardware and algorithms have been developed to transfer electrical power and data connectivity safely, efficiently, and automatically from an identified damaged/defective wire in a cable to an alternate wire path. The combination of online cable testing capabilities, along with intelligent signal rerouting algorithms, allows the user to overcome the inherent difficulty of maintaining system integrity and configuration control, while autonomously rerouting signals and functions without introducing new failure modes. The incorporation of this capability will increase the reliability of systems by ensuring system availability during operations.

  5. Equalization of data transmission cable

    Zobrist, G. W.

    1975-01-01

    The paper describes an equalization approach utilizing a simple RLC network which can obtain a maximum slope of -12dB/octave for reshaping the frequency characteristics of a data transmission cable, so that data may be generated and detected at the receiver. An experimental procedure for determining equalizer design specifications using distortion analysis is presented. It was found that for lengths of 16 PEV-L cable of up to 5 miles and data transmission rates of up to 1 Mbs, the equalization scheme proposed here is sufficient for generation of the data with acceptable error rates.

  6. Development of the communication cable suspending robot. Automation of cable suspending works; Tsushin cable tsurika robot no kaihatsu. Cable tsurika sagyo no jidoka

    Maeda, T. [Kansai Electaric Power Co. Inc., Osaka (Japan)

    2000-04-01

    The automatic communication cable suspending robot was developed. For disuse of dangerous stringers and improvement of suspending workability, adoption of the new mechanical high-speed labor-saving cable laying method was decided regardless of current communication cable laying methods. This robot can deal with automatic removal works of existing cable hangers which has been thought to be extremely difficult, and thus integration works of many cables by a cable hanger in cable additional installation work. For easy handling of the robot, the robot body is composed of 6 separated parts such as driving part, power source part, cable draw-in part, hanger attaching part, hanger removing part and hanger recovering part according to each function. For avoiding troubles with telephone lines and CATV lines in city areas, the size and mass of the robot were considered enough. After this, some verification tests on the robot effectiveness including performance test, workability test on dummy poles, and field test are scheduled. (NEDO)

  7. North American Submarine Cable Association (NASCA) Submarine Cables

    National Oceanic and Atmospheric Administration, Department of Commerce — These data show the locations of in-service and out-of-service submarine cables that are owned by members of NASCA and located in U.S. territorial waters. More...

  8. 47 CFR 76.640 - Support for unidirectional digital cable products on digital cable systems.

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Support for unidirectional digital cable products on digital cable systems. 76.640 Section 76.640 Telecommunication FEDERAL COMMUNICATIONS... Standards § 76.640 Support for unidirectional digital cable products on digital cable systems. (a)...

  9. Dynamic Underground Stripping Project

    LLNL is collaborating with the UC Berkeley College of Engineering to develop and demonstrate a system of thermal remediation and underground imaging techniques for use in rapid cleanup of localized underground spills. Called ''Dynamic Stripping'' to reflect the rapid and controllable nature of the process, it will combine steam injection, direct electrical heating, and tomographic geophysical imaging in a cleanup of the LLNL gasoline spill. In the first 8 months of the project, a Clean Site engineering test was conducted to prove the field application of the techniques before moving the contaminated site in FY 92

  10. Improvements in electric cable gland seals

    An electric cable gland seal has a deformable sealing member which is penetrated by cables arranged in annular spaced array, the sealing member being disposed between two spreader plates which when urged together by springs compress and deform the sealing member into sealing contact with the cables, a distributor which holds the cables in the spaced array, and a cylindrical body adapted for sealing about an opening in the wall of a vessel. (UK)

  11. The Application of Novel Polypropylene to the Insulation of Electric Power Cable (2)

    Miyashita, Yoshitsugu; Demura, Tsuyoshi; Ueda, Asakiyo; Someya, Akira; Kawahigashi, Masaki; Murakami, Tsuyoshi; Matsuda, Yoshiji; Kurahashi, Kiyoshi; Yoshino, Katsumi

    The authors had investigated the basic properties of newly developed stereoregular syndiotactic polypropylene (s-PP) which had been synthesized with homogeneous metallocene catalyst, in the previous paper. As the result of this, it was revealed that s-PP had superior thermal and electrical properties to cross-linked polyethylene (XLPE) which was adopted as conventional insulating material for high voltage power cable. In this paper, we estimated the possibility to apply s-PP to the actual power cable from the viewpoint of long-term thermal durability and processability. Consequently, it was found that the thermal stability of s-PP could be significantly improved by adding both hindered phenol and sulfur antioxidants, and wide molecular weight distribution of s-PP contributed to good processability during extrusion. On the basis of these results, 600V and 22kV class cables with insulation of s-PP were manufactured. Successfully manufactured cables proposed that s-PP could be available to electric power cable. Lightning Impulse and AC breakdown strength of both cables at the temperature range of RT to 120°C will be discussed.

  12. Cable Insulation Breakdowns in the Modulator with a Switch Mode High Voltage Power Supply

    Cours, A

    2004-01-01

    The Advanced Photon Source modulators are PFN-type pulsers with 40 kV switch mode charging power supplies (PSs). The PS and the PFN are connected to each other by 18 feet of high-voltage (HV) cable. Another HV cable connects two separate parts of the PFN. The cables are standard 75 kV x-ray cables. All four cable connectors were designed by the PS manufacturer. Both cables were operating at the same voltage level (about 35 kV). The PS’s output connector has never failed during five years of operation. One of the other three connectors failed approximately five times more often than the others. In order to resolve the failure problem, a transient analysis was performed for all connectors. It was found that transient voltage in the connector that failed most often was subjected to more high-frequency, high-amplitude AC components than the other three connectors. It was thought that these components caused partial discharge in the connector insulation and led to the insulation breakdown. Modification o...

  13. Your Personal Genie in the Cable.

    Schlafly, Hubert J.

    The technology necessary for the use of cable television (TV) has been invented; it simply must be put to use. By the 1970's, cable TV should be commonplace in this country. Its rapid growth was caused in part by its appearance at a time of explosive expansion of related technologies like data theory and computer design. The coaxial cable system…

  14. EMP coupling to multiconductor shielded cables

    A method is presented for calculating EMP coupling to multiconductor shielded cables by electromagnetic pulse. The induced voltage of inner conductor of the SYV-50-7 cable and SYVZ-9 cable placed on the ground are computed. The computed results agree with those measured

  15. Using Cable Television for Library Data Transmission.

    Whitaker, Douglas A.

    1985-01-01

    Discusses information gained from a test of cable data circuits on a Geac bibliographic control system at the Wayne Oakland Library Federation (WOLF) (Michigan). Highlights include an introduction to cable, hardware profile, the WOLF experience, and key questions that will affect the future use of cable for data transmission. (EJS)

  16. Evaluation of AC losses for HT-7U CICC on plasma disruption

    AC loss is one of the main issues in the design of the CICC used for PF and TF coils of superconducting tokamak. A preliminary calculation of AC loss for the designed HT-7U CICCs used for TF magnets is given. The authors only consider the hysteresis and coupling losses related to transversal and longitudinal kinds. In addition to the strand resistive barriers (Pb-30Sn-2Sb coating for NbTi strands), a stainless steel strip has been used inside these cables to reduce the AC loss in this kind of conductor. The available theory has enabled to emphasize the role played by the stainless steel strip in the reduction of total AC losses in this kind of conductor. It was shown that AC losses of cable were affected by the structure and change rate of magnetic field

  17. Underground Storage Tanks in Iowa

    Iowa State University GIS Support and Research Facility — Underground storage tank (UST) sites which store petroleum in Iowa. Includes sites which have been reported to DNR, and have active or removed underground storage...

  18. Raman distributed temperature sensing in underground geoexchange system

    Giuseffi, Marie; Ferdinand, Pierre; Vrain, Alexandre; Philippe, Mikael; Lesueur, Hervé

    2010-09-01

    Underground heat exchangers are instrumented by eight multimode optical fiber cables connected to a distributed temperature sensing (DTS) Raman system which provides real time temperature monitoring, versus operational conditions of the installation. A user-friendly Labview® software has been developed, allowing the configuration of the full installation, the signal processing of raw DTS data and storage, as well as the visualization of any temperature profile, on request. Preliminary temperature profiles are very promising. This platform will allow R&D about geothermal exchanges, will provide a full scale bench to characterize new equipments, and will encourage professionals to develop this renewable energy sector.

  19. ALOHA Cabled Observatory: Early Results

    Howe, B. M.; Lukas, R.; Duennebier, F. K.

    2011-12-01

    The ALOHA Cabled Observatory (ACO) was installed 6 June 2011, extending power, network communications and timing to a seafloor node and instruments at 4726 m water depth 100 km north of Oahu. The system was installed using ROV Jason operated from the R/V Kilo Moana. Station ALOHA is the field site of the Hawaii Ocean Time-series (HOT) program that has investigated temporal dynamics in biology, physics, and chemistry since 1988. HOT conducts near monthly ship-based sampling and makes continuous observations from moored instruments to document and study climate and ecosystem variability over semi-diurnal to decadal time scales. The cabled observatory system will provide the infrastructure for continuous, interactive ocean sampling enabling new measurements as well as a new mode of ocean observing that integrates ship and cabled observations. The ACO is a prototypical example of a deep observatory system that uses a retired first-generation fiber-optic telecommunications cable. Sensors provide live video, sound from local and distant sources, and measure currents, pressure, temperature, and salinity. Preliminary results will be presented and discussed.

  20. Inflation and the underground economy

    Ahiabu, Stephen

    2006-01-01

    This paper studies the optimal rate of seigniorage in an economy characterized by decentralized trade and a tax-evading underground sector. The economy has buyers, some of whom visit the formal market, while others visit the underground market. I find that the optimal rate of inflation depends on which of the two sectors, formal or underground, is more crowded/congested with buyers. If the underground sector is more crowded, the optimal inflation rate is as high as 42% per a...

  1. Underground Economy in Croatia

    Marija Švec

    2009-12-01

    Full Text Available The subject of this paper is to estimate the size of underground economy in the period 2001-2007 using labour approach. Two types of data are used: administrative and survey. The main questions are: How did the activity rates move? What is the relationship between activity rates and the size of shadow economy? Is there correlation between official employment, official unemployment and unofficial employment (shadow economy and what is it like? What is the position of Croatia considering the members of the European Union? It is presumed that the increase of activity rates causes decrease of underground economy. However, this assumption is valid only for administrative data. Correlation analysis is based on regression models and given results are quite logical. If Croatian and European underground economy is compared, it can be confirmed that the position of Croatia is extremely poor. Given results are approximative and show the level of Croatian underground economy which is presumably underestimated. These phenomena occur because of available statistics and method limitations

  2. Advanced method for cable aging evaluation

    The project of 'Assessment of Cable Aging for Nuclear Power Plants' started in FY2002. Until the end of FY2006, approximately 80% of the planned aging data has been acquired by the cable aging evaluation tests. The LOCA tests for nine kinds of cables were also conducted using the simultaneous aging specimens. Based on these results, the outlines of 'Guidelines for environmental qualification test for cables (Draft)' were developed. And a tentative assessment for seven kinds of cables was made using data acquired until present according to the outlines of guidelines. (author)

  3. Aeolic vibration of aerial electricity transmission cables

    Avila, A.; Rodriguez-Vera, Ramon; Rayas, Juan A.; Barrientos, Bernardino

    2005-02-01

    A feasibility study for amplitude and frequency vibration measurement in aerial electricity transmission cable has been made. This study was carried out incorporating a fringe projection method for the experimental part and horizontal taut string model for theoretical one. However, this kind of model ignores some inherent properties such as cable sag and cable inclination. Then, this work reports advances on aeolic vibration considering real cables. Catenary and sag are considered in our theoretical model in such a way that an optical theodolite for measuring has been used. Preliminary measurements of the catenary as well as numerical simulation of a sagged cable vibration are given.

  4. Grounding Effect on Common Mode Interference of Underground Inverter

    CHENG Qiang

    2013-09-01

    Full Text Available For the neutral point not grounded characteristics of underground power supply system in coal mine, this paper studied common mode equivalent circuit of underground PWM inverter, and extracted parasitic parameters of interference propagation path. The author established a common mode and differential mode model of underground inverter. Taking into account the rise time of PWM, the simulation results of conducted interference by Matlab software is compared with measurement spectrum on the AC side and motor side of converter, the difference is consistent showing that the proposed method has some validity. After Comparison of calculation results by Matlab simulation ,it can be concluded that ungrounded neutral of transformer could redue common mode current in PWM system, but not very effective, the most efficient way is to increase grounding  impedance of  inverter and motor.

  5. Offshore Cable Installation - Lillgrund. Lillgrund Pilot Project

    Unosson, Oscar (Vattenfall Vindkraft AB, Stockholm (Sweden))

    2009-01-15

    This report describes the installation method and the experiences gained during the installation of the submarine cables for the offshore wind farm at Lillgrund. The wind farm consists of 48 wind turbines and is expected to produce 0.33 TWh annually. Different aspects of the installation, such as techniques, co-operation between the installation teams, weather conditions and regulatory and environmental issues are described in this report. In addition, recommendations and guidelines are provided, which hopefully can be utilised in future offshore wind projects. The trenches, in which the submarine cables were laid, were excavated weeks before the cable laying. This installation technique proved to be successful for the laying of the inter array cables. The export cable, however, was laid into position with difficulty. The main reason why the laying of the export cable proved more challenging was due to practical difficulties connected with the barge entrusted with the cable laying, Nautilus Maxi. The barge ran aground a number of times and it had difficulties with the thrusters, which made it impossible to manoeuvre. When laying the inter array cables, the method specification was closely followed, and the laying of the cables was executed successfully. The knowledge and experience gained from the offshore cable installation in Lillgrund is essential when writing technical specifications for new wind plant projects. It is recommended to avoid offshore cable installation work in winter seasons. That will lower the chances of dealing with bad weather and, in turn, will reduce the risks

  6. Self-healing cable apparatus and methods

    Huston, Dryver (Inventor); Esser, Brian (Inventor)

    2007-01-01

    Self-healing cable apparatus and methods are disclosed. The cable has a central core surrounded by an adaptive cover that can extend over the entire length of the cable or just one or more portions of the cable. The adaptive cover includes a protective layer having an initial damage resistance, and a reactive layer. When the cable is subjected to a localized damaging force, the reactive layer responds by creating a corresponding localized self-healed region. The self-healed region provides the cable with enhanced damage resistance as compared to the cable's initial damage resistance. Embodiments of the invention utilize conventional epoxies or foaming materials in the reactive layer that are released to form the self-healed region when the damaging force reaches the reactive layer.

  7. Electrical testing of generator station cables

    Tests have been performed at a decommissioned nuclear plant to assess the ability of electrical diagnostic tests to determine the remaining life of cable insulation. Power and control cables with either SBR or PVC insulation were tested. These materials are typical of cables in plants built before 1960. Insulation resistance, capacitance, dissipation factor and partial discharge activity were not correlated to the dc breakdown voltage of the cables, which is taken as a measure of insulation condition. Thus it is uncertain if such tests can be used to predict remaining life, especially if historical data has not been collected. All the cables had very high dc breakdown voltages, which was consistent with the generally good physical condition of the cables. Based on this limited study, it seems that hipot tests may be the only convenient electrical method currently available to assure the condition of cables in a generating station undergoing life extension. However more work is needed to determine suitable hipot test voltages

  8. Corrosion monitoring of carbon steel in the bentonite in deep underground

    In previous study, a corrosion sensor has been developed and its applicability to monitoring of the corrosion behavior of carbon steel overpack has been confirmed. In this study, a simulated overpack was placed with buffer material composed mainly of bentonite in test tunnel of 350 m deep underground constructed at Horonobe underground research laboratory. The corrosion monitoring was performed by AC impedance method using the corrosion sensors embeded in the buffer material. (author)

  9. Ripple current loss measurement with DC bias condition for high temperature superconducting power cable using calorimetry method

    Kim, D.W.; Kim, J.G.; Kim, A.R. [Changwon National University, 9 sarim-dong, Changwon 641-773 (Korea, Republic of); Park, M., E-mail: paku@changwon.ac.k [Changwon National University, 9 sarim-dong, Changwon 641-773 (Korea, Republic of); Yu, I.K. [Changwon National University, 9 sarim-dong, Changwon 641-773 (Korea, Republic of); Sim, K.D.; Kim, S.H.; Lee, S.J.; Cho, J.W. [Superconducting Device and Cryogenics Group, Korea Electrotechnology Research Institute, Changwon, 641-120 (Korea, Republic of); Won, Y.J. [Korea Electric Power Corporation, 411, youngdong-dearo, Gangnam-gu, Seoul (Korea, Republic of)

    2010-11-01

    The authors calculated the loss of the High Temperature Superconducting (HTS) model cable using Norris ellipse formula, and measured the loss of the model cable experimentally. Two kinds of measuring method are used. One is the electrical method, and the other is the calorimetric method. The electrical method can be used only in AC condition. But the calorimetric method can be used in both AC and DC bias conditions. In order to propose an effective measuring approach for Ripple Dependent Loss (RDL) under DC bias condition using the calorimetric method, Bismuth Strontium Calcium Copper Oxide (BSCCO) wires were used for the HTS model cable, and the SUS tapes were used as a heating tape to make the same pattern of the temperature profiles as in the electrical method without the transport current. The temperature-loss relations were obtained by the electrical method, and then applied to the calorimetric method by which the RDL under DC bias condition was well estimated.

  10. Ripple current loss measurement with DC bias condition for high temperature superconducting power cable using calorimetry method

    The authors calculated the loss of the High Temperature Superconducting (HTS) model cable using Norris ellipse formula, and measured the loss of the model cable experimentally. Two kinds of measuring method are used. One is the electrical method, and the other is the calorimetric method. The electrical method can be used only in AC condition. But the calorimetric method can be used in both AC and DC bias conditions. In order to propose an effective measuring approach for Ripple Dependent Loss (RDL) under DC bias condition using the calorimetric method, Bismuth Strontium Calcium Copper Oxide (BSCCO) wires were used for the HTS model cable, and the SUS tapes were used as a heating tape to make the same pattern of the temperature profiles as in the electrical method without the transport current. The temperature-loss relations were obtained by the electrical method, and then applied to the calorimetric method by which the RDL under DC bias condition was well estimated.

  11. An Analytical Benchmark for the Calculation of Current Distribution in Superconducting Cables

    Bottura, L; Fabbri, M G

    2002-01-01

    The validation of numerical codes for the calculation of current distribution and AC loss in superconducting cables versus experimental results is essential, but could be affected by approximations in the electromagnetic model or incertitude in the evaluation of the model parameters. A preliminary validation of the codes by means of a comparison with analytical results can therefore be very useful, in order to distinguish among different error sources. We provide here a benchmark analytical solution for current distribution that applies to the case of a cable described using a distributed parameters electrical circuit model. The analytical solution of current distribution is valid for cables made of a generic number of strands, subjected to well defined symmetry and uniformity conditions in the electrical parameters. The closed form solution for the general case is rather complex to implement, and in this paper we give the analytical solutions for different simplified situations. In particular we examine the ...

  12. Study on the effects of cable sliding motion on the seismic response of cable tray

    In various industrial plants such as thermal power plants, nuclear power plants or chemical plants, many cable trays are generally used for supporting cables by which control signals will be transmitted. Cable trays are generally made by thin steel plates both sides of which are folded in the vertical direction, while cables are simply placed on the tray. Thus, cables begin to slides when the response acceleration of trays exceeds some amount of value. Consequently, seismic responses of cable tray will also depend on the occurrence of sliding motion of cables. Therefore, cable trays are seen as highly nonlinear structural systems. In this study, seismic responses of the cable tray are investigated analytically considering the cable sliding motions. A cable tray is modeled by a two-degree-of-freedom system. Response acceleration and displacement of the tray and the cable are evaluated for seismic inputs. It is confirmed that the sliding motion of the cable has very large influences on the seismic responses of the cable tray. (author)

  13. LUNA: Nuclear astrophysics underground

    Underground nuclear astrophysics with LUNA at the Laboratori Nazionali del Gran Sasso spans a history of 20 years. By using the rock overburden of the Gran Sasso mountain chain as a natural cosmic-ray shield very low signal rates compared to an experiment on the surface can be tolerated. The cross sectons of important astrophysical reactions directly in the stellar energy range have been successfully measured. In this proceeding we give an overview over the key accomplishments of the experiment and an outlook on its future with the expected addition of an additional accelerator to the underground facilities, enabling the coverage of a wider energy range and the measurement of previously inaccessible reactions

  14. Jiangmen Underground Neutrino Observatory

    He, Miao

    2014-01-01

    The Jiangmen Underground Neutrino Observatory (JUNO) is a multipurpose neutrino-oscillation experiment designed to determine the neutrino mass hierarchy and to precisely measure oscillation parameters by detecting reactor antineutrinos, observe supernova neutrinos, study the atmospheric, solar neutrinos and geo-neutrinos, and perform exotic searches, with a 20 kiloton liquid scintillator detector of unprecedented $3\\%$ energy resolution (at 1 MeV) at 700-meter deep underground and to have other rich scientific possibilities. Currently MC study shows a sensitivity of the mass hierarchy to be $\\overline{\\Delta\\chi^2}\\sim 11$ and $\\overline{\\Delta\\chi^2}\\sim 16$ in a relative and an absolute measurement, respectively. JUNO has been approved by Chinese Academy of Sciences in 2013, and an international collaboration was established in 2014. The civil construction is in preparation and the R$\\&$D of the detectors are ongoing. A new offline software framework was developed for the detector simulation, the event ...

  15. Underground Economy in Croatia

    Marija Švec

    2009-01-01

    The subject of this paper is to estimate the size of underground economy in the period 2001-2007 using labour approach. Two types of data are used: administrative and survey. The main questions are: How did the activity rates move? What is the relationship between activity rates and the size of shadow economy? Is there correlation between official employment, official unemployment and unofficial employment (shadow economy) and what is it like? What is the position of Croatia considering the m...

  16. Nuclear plant undergrounding

    Under Section 25524.3 of the Public Resources Code, the California Energy Resources Conservation and Development Commission (CERCDC) was directed to study ''the necessity for '' and the effectiveness and economic feasibility of undergrounding and berm containment of nuclear reactors. The author discusses the basis for the study, the Sargent and Lundy (S and L) involvement in the study, and the final conclusions reached by S and L

  17. Monitoring underground movements

    Antonella Del Rosso

    2015-01-01

    On 16 September 2015 at 22:54:33 (UTC), an 8.3-magnitude earthquake struck off the coast of Chile. 11,650 km away, at CERN, a new-generation instrument – the Precision Laser Inclinometer (PLI) – recorded the extreme event. The PLI is being tested by a JINR/CERN/ATLAS team to measure the movements of underground structures and detectors.   The Precision Laser Inclinometer during assembly. The instrument has proven very accurate when taking measurements of the movements of underground structures at CERN.    The Precision Laser Inclinometer is an extremely sensitive device capable of monitoring ground angular oscillations in a frequency range of 0.001-1 Hz with a precision of 10-10 rad/Hz1/2. The instrument is currently installed in one of the old ISR transfer tunnels (TT1) built in 1970. However, its final destination could be the ATLAS cavern, where it would measure and monitor the fine movements of the underground structures, which can affect the precise posi...

  18. Experimental verification of the effect of cable length on voltage distribution in stator winding of an induction motor under surge condition

    Oyegoke, B.S. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Electromechanics

    1997-12-31

    This paper presents the results of surge distribution tests performed on a stator of a 6 kV induction motor. The primary aim of these tests was to determine the wave propagation properties of the machine winding fed via cables of different lengths. Considering the measured resorts, conclusions are derived regarding the effect of cable length on the surge distribution within the stator winding of an ac motor. (orig.) 15 refs.

  19. Performance evolution of 60 kA HTS cable prototypes in the EDIPO test facility

    Bykovsky, N.; Uglietti, D.; Sedlak, K.; Stepanov, B.; Wesche, R.; Bruzzone, P.

    2016-08-01

    During the first test campaign of the 60 kA HTS cable prototypes in the EDIPO test facility, the feasibility of a novel HTS fusion cable concept proposed at the EPFL Swiss Plasma Center (SPC) was successfully demonstrated. While the measured DC performance of the prototypes at magnetic fields from 8 T to 12 T and for currents from 30 kA to 70 kA was close to the expected one, an initial electromagnetic cycling test (1000 cycles) revealed progressive degradation of the performance in both the SuperPower and SuperOx conductors. Aiming to understand the reasons for the degradation, additional cycling (1000 cycles) and warm up-cool down tests were performed during the second test campaign. I c performance degradation of the SuperOx conductor reached ∼20% after about 2000 cycles, which was reason to continue with a visual inspection of the conductor and further tests at 77 K. AC tests were carried out at 0 and 2 T background fields without transport current and at 10 T/50 kA operating conditions. Results obtained in DC and AC tests of the second test campaign are presented and compared with appropriate data published recently. Concluding the first iteration of the HTS cable development program at SPC, a summary and recommendations for the next activity within the HTS fusion cable project are also reported.

  20. Stability of Nb-Ti Rutherford Cables Exhibiting Different Contact Resistances

    Willering, G P; Kaugerts, J; ten Kate, H H J

    2008-01-01

    Dipole magnets for the so-called SIS-300 heavy-ion synchrotron at GSI are designed to generate 6 T with a field sweep rate of 1 T/s. It is foreseen to wind the magnets with a 36 strands Nb-Ti Rutherford cable. An important issue in the cable design is sufficiently low AC loss and stability as well. In order to keep the AC loss at low level, the contact resistance between crossing strands Rc is kept high by putting a stainless steel core in the cable. The contact resistance between adjacent strands Ra is controlled by oxidation of the Sn-Ag coating of the strands, like in the LHC. In order to investigate the effect of Ra on the stability of the cable, we prepared four samples with different Ra by varying the heat treatment and applying a soldering technique, resulting in values between 1 mW to 9 mW. The stability of each sample against transient point-like heat pulses was measured. The results of the stability experiments and a comparison with calculations using the network model CUDI are presented...

  1. The Mathematical Modelling of Heat Transfer in Electrical Cables

    Bugajev Andrej

    2014-05-01

    Full Text Available This paper describes a mathematical modelling approach for heat transfer calculations in underground high voltage and middle voltage electrical power cables. First of the all typical layout of the cable in the sand or soil is described. Then numerical algorithms are targeted to the two-dimensional mathematical models of transient heat transfer. Finite Volume Method is suggested for calculations. Different strategies of nonorthogonality error elimination are considered. Acute triangles meshes were applied in two-dimensional domain to eliminate this error. Adaptive mesh is also tried. For calculations OpenFOAM open source software which uses Finite Volume Method is applied. To generate acute triangles meshes aCute library is used. The efficiency of the proposed approach is analyzed. The results show that the second order of convergence or close to that is achieved (in terms of sizes of finite volumes. Also it is shown that standard strategy, used by OpenFOAM is less efficient than the proposed approach. Finally it is concluded that for solving real problem a spatial adaptive mesh is essential and adaptive time steps also may be needed.

  2. Environment Of Underground Water And Pollution

    Han, Jeong Sang

    1998-02-15

    This book deals with environment of underground water and pollution, which introduces the role of underground water in hydrology, definition of related study of under water, the history of hydro-geology, basic conception of underground water such as origin of water, and hydrogeologic characteristic of aquifers, movement of underground water, hydrography of underground water and aquifer test analysis, change of an underground water level, and water balance analysis and development of underground water.

  3. Environment Of Underground Water And Pollution

    This book deals with environment of underground water and pollution, which introduces the role of underground water in hydrology, definition of related study of under water, the history of hydro-geology, basic conception of underground water such as origin of water, and hydrogeologic characteristic of aquifers, movement of underground water, hydrography of underground water and aquifer test analysis, change of an underground water level, and water balance analysis and development of underground water.

  4. Development of a 10 m long superconducting multistrand conductor for power transmission cables

    A 10 m long HTS cable conductor was stranded with an industrial winding process from 2 km of Ag/Bi2223 tapes. It was installed in a vacuum cryostat and was force cooled by pressurized liquid nitrogen. DC- and AC-load tests were performed while varying the frequency and amplitude of the current. The critical current of the conductor is 5000 A. This model of a power transmission cable demonstrates very low AC losses of 0.8 W m-1 at 2000 Arms/50 Hz measured both with an electric transport and a calorimetric method. The AC losses vary linearly with frequency, P ∝ f, and have a current dependence slightly lower than P ∝ I3. The magnitude of the losses is clearly lower than predicted by the block model version of the Bean model. The model for uniform current distribution (UCD) improves the quantitative description of the losses. From these experiments we conclude that our low loss winding design of the conductor is an early stage of an economical HTS power transmission cable. (author)

  5. Critical state solution of a cable made of curved thin superconducting tapes

    In this paper, we develop a method based on the critical state for calculating the current and field distributions and AC losses in a cable made of curved thin superconducting tapes. The method also includes the possibility of considering spatial variation of the critical current density, which may be the result of the manufacturing process. For example, rare-earth-based coated conductors are known to have a decrease in transport properties near the edges of the tape: this influences the way the current and field penetrate the sample and, consequently, the AC losses. We demonstrate that curved tapes arranged on a cylindrical former behave as an infinite horizontal stack of straight tapes, and we compare the AC losses in a variety of working conditions, both without and with the lateral dependence of the critical current density. This model and subsequent similar approaches can be of interest for various applications of coated conductors, including power cables and conductor-on-round-core cables. (paper)

  6. AC losses in circular arrangements of parallel superconducting tapes

    Kühle (fratrådt), Anders Van Der Aa; Træholt, Chresten; Däumling, Manfred; Olsen, Søren Krüger; Tønnesen, Ole

    The DC and AC properties of superconducting tapes connected in parellel and arranged in a single closed layer on two tubes (correspondig to power cable models with infinite pitch) with different diameters are compared. We find that the DC properties, i.e. the critical currents of the two arrangem......The DC and AC properties of superconducting tapes connected in parellel and arranged in a single closed layer on two tubes (correspondig to power cable models with infinite pitch) with different diameters are compared. We find that the DC properties, i.e. the critical currents of the two...... arrangements, scale with the number of tapes and hence appear to be independent of the diameter.However, the AC loss per tape (for a given current per tape) appears to decrease with increasing diameter of the circular arrangement. Compared to a model for the AC loss in a continuous superconducting layer...... (Monoblock model) the measured values are about half an order of magnitude higher than expected for the small diameter arrangement. When compared to the AC loss calculated for N individual superconducting tapes using a well known model ( Norris elliptical) the difference is slightly smaller....

  7. AC losses in circular arrangements of parallel superconducting tapes

    Kühle (fratrådt), Anders Van Der Aa; Træholt, Chresten; Däumling, Manfred;

    1998-01-01

    The DC and AC properties of superconducting tapes connected in parellel and arranged in a single closed layer on two tubes (correspondig to power cable models with infinite pitch) with different diameters are compared. We find that the DC properties, i.e. the critical currents of the two arrangem......The DC and AC properties of superconducting tapes connected in parellel and arranged in a single closed layer on two tubes (correspondig to power cable models with infinite pitch) with different diameters are compared. We find that the DC properties, i.e. the critical currents of the two...... arrangements, scale with the number of tapes and hence appear to be independent of the diameter.However, the AC loss per tape (for a given current per tape) appears to decrease with increasing diameter of the circular arrangement. Compared to a model for the AC loss in a continuous superconducting layer...... (Monoblock model) the measured values are about half an order of magnitude higher than expected for the small diameter arrangement. When compared to the AC loss calculated for N individual superconducting tapes using a well known model ( Norris elliptical) the difference is slightly smaller....

  8. Free and forced convective cooling of pipe-type electric cables. Volume 2: electrohycrodynamic pumping. Final report

    Chato, J.C.; Crowley, J.M.

    1981-05-01

    A multi-faceted research program has been performed to investigate in detail several aspects of free and forced convective cooling of underground electric cable systems. There were two main areas of investigation. The first one, reported in Volume 1, dealt with the fluid dynamic and thermal aspects of various components of the cable system. In particular, friction factors for laminar flow in the cable pipes with various configurations were determined using a finite element technique; the temperature distributions and heat transfer in splices were examined using a combined analytical numerical technique; the pressure drop and heat transfer characteristics of cable pipes in the transitional and turbulent flow regime were determined experimentally in a model study; and full-scale model experimental work was carried out to determine the fluid dynamic and thermal characteristics of entrance and exit chambers for the cooling oil. The second major area of activity, reported in this volume, involved a feasibility study of an electrohydrodynamic pump concept utilizing a traveling electric field generated by a pumping cable. Experimental studies in two different configurations as well as theoretical calculations showed that an electrohydrodynamic pump for the moving of dielectric oil in a cable system is feasible.

  9. Modeling and Filter Design for Overvoltage Mitigation in a Motor Drive System with a Long Cable

    Matsumura, Itaru; Akagi, Hirofumi

    This paper presents an intensive discussion on modeling an adjustable-speed motor drive system consisting of a voltage-source PWM inverter and an induction motor that are connected by a three-phase symmetric, long cable with a grounding wire lead. Then, it describes a design procedure for a parallel-connected R-L filter in each phase that can mitigate the overvoltage appearing at the motor terminals. The model developed in this paper focuses on the inherent “ringing frequency” of the cable, where the ringing frequency is inversely proportional to cable length. When no filter is used, the so-called “impedance mismatch” causes the reflection of a voltage-traveling wave at both the inverter and the motor terminals. As a result, the impedance mismatch generates an overvoltage that may reach twice the inverter dc-link voltage at the motor terminals. The overvoltage may damage the motor-winding insulation, and may cause it to breakdown. Although an R-L filter installed on the ac side of the inverter can reduce the overvoltage, it would be difficult to design the filter effectively for long cables of different lengths. The effectiveness and validity of the simple design procedure described in this paper are confirmed on a 400-V, 15-kW experimental system with either a 100-m or 200-m-long cable.

  10. Field application of a cable NDT system for cable-stayed bridge using MFL sensors integrated

    In this study, an automated cable non-destructive testing(NDT) system was developed to monitor the steel cables that are a core component of cable-stayed bridges. The magnetic flux leakage(MFL) method, which is suitable for ferromagnetic continuum structures and has been verified in previous studies, was applied to the cable inspection. A multi-channel MFL sensor head was fabricated using hall sensors and permanent magnets. A wheel-based cable climbing robot was fabricated to improve the accessibility to the cables, and operating software was developed to monitor the MFL-based NDT research and control the climbing robot. Remote data transmission and robot control were realized by applying wireless LAN communication. Finally, the developed element techniques were integrated into an MFL-based cable NDT system, and the field applicability of this system was verified through a field test at Seohae Bridge, which is a typical cable-stayed bridge currently in operation.

  11. Cable force monitoring system of cable stayed bridges using accelerometers inside mobile smart phone

    Zhao, Xuefeng; Yu, Yan; Hu, Weitong; Jiao, Dong; Han, Ruicong; Mao, Xingquan; Li, Mingchu; Ou, Jinping

    2015-03-01

    Cable force is one of the most important parameters in structural health monitoring system integrated on cable stayed bridges for safety evaluation. In this paper, one kind of cable force monitoring system scheme was proposed. Accelerometers inside mobile smart phones were utilized for the acceleration monitoring of cable vibration. Firstly, comparative tests were conducted in the lab. The test results showed that the accelerometers inside smartphones can detect the cable vibration, and then the cable force can be obtained. Furthermore, there is good agreement between the monitoring results of different kinds of accelerometers. Finally, the proposed cable force monitoring system was applied on one cable strayed bridge structure, the monitoring result verified the feasibility of the monitoring system.

  12. Occupational Asthma in a Cable Manufacturing Company

    Attarchi, Mirsaeed; Dehghan, Faezeh; Yazdanparast, Taraneh; Mohammadi, Saber; Golchin, Mahdie; Sadeghi, Zargham; Moafi, Masoud; Seyed Mehdi, Seyed Mohammad

    2014-01-01

    Background: During the past decade, incidence of asthma has increased, which might have been due to environmental exposures. Objectives: Considering the expansion of cable manufacturing industry in Iran, the present study was conducted to evaluate the prevalence of occupational asthma in a cable manufacturing company in Iran as well as its related factors. Patients and Methods: This study was conducted on employees of a cable manufacturing company in Yazd, Iran, in 2012. The workers were divi...

  13. Review of high voltage direct current cables

    Chen, George; Miao, Hao; Z. Xu; A. S. Vaughan; Cao, Junzheng; Wang, Haitian

    2015-01-01

    Increased renewable energy integration and international power trades have led to the construction and development of new HVDC transmission systems. HVDC cables, in particular, play an important role in undersea power transmission and offshore renewable energy integration having lower losses and higher reliability. In this paper, the current commercial feasibility of HVDC cables and the development of different types of HVDC cables and accessories are reviewed. The non-uniform electric field ...

  14. Optimal Sensor Placement for Stay Cable Damage Identification of Cable-Stayed Bridge under Uncertainty

    Li-Qun Hou; Xue-Feng Zhao; Rui-Cong Han; Chun-Cheng Liu

    2013-01-01

    Large cable-stayed bridges utilize hundreds of stay cables. Thus, placing a sensor on every stay cable of bridges for stay cable damage identification (SCDI) is costly and, in most cases, not necessary. Optimal sensor placement is a significant and critical issue for SCDI. This paper proposes the criteria for sensor quantity and location optimization for SCDI on the basis of the concept of damage identification reliability index (DIRI) under uncertainty. Random elimination (RE) algorithm and ...

  15. The underground economy in Romania

    Eugenia Ramona MARA

    2011-01-01

    The actual economic crisis has a major impact on the underground economy because of tax burden increase especially. This study realizes an analysis of the major implications of the economic crises on the size and the consequences of the underground activities. Also we try to reveal the correlation between the underground economy and the official one. The conclusion of this study is that the shadow activities have grown since the financial crisis began.

  16. Underground economy and aggregate fluctuations

    Juan Carlos Conesa Roca; Carlos Díaz Moreno; José Enrique Galdón Sánchez

    2001-01-01

    This paper explores the role of underground economic activities as an explanation of differences in registered aggregate fluctuations. In order to do so, we introduce an underground economy sector in an otherwise standard Real Business Cycle model and calibrate it to the USA economy. We find that, at low frequencies, Europe fluctuates more than the USA, while its participation rate is smaller. The existence of underground activities rationalizes the negative relationship between participation...

  17. How do you like them cables?

    Sergei Malyukov

    Cabling work is not for clautrophobic people! Cables are like the blood vessels and nervous system of ATLAS. With the help of all these cables, we can power ATLAS, control the detector and read out the data. Like the human blood vessels, they penetrate inside the ATLAS volume, reaching each of its elements. The ATLAS developers started to think about design of services, cables and pipes at the very first stages of the project. The cabling project has been developing most intensively during the last five years, passing through the projection and CAD design phases, then the installation of cable trays and finally the cables. The cable installation itself took two and a half years and was done by teams of technicians from several institutes from Russia, the Czech Republic and Poland. Here are some numbers to illustrate the scale of the ATLAS cabling system. More than 25000 optical fiber channels are used for reading the information from the sub-detectors and delivering the timing signals. The total numbe...

  18. Underground nuclear waste containments

    In the United States, about a hundred million gallons of high-level nuclear waste are stored in underground containments. Basically, these containments are of two different designs: single-shell and double-shell structures. The single-shell structures consist of reinforced concrete cylindrical walls seated on circular mats and enclosed on top with torispherical domes or circular flat roofs. The walls and the basemats are lined with carbon steel. The double-shell structures provide another layer of protection and constitute a completely enclosed steel containment within the single-shell structure leaving an annular space between the two walls. Single-shell containments are of earlier vintage and were built in the period 1945-1965. Double-shell structures were built through the 1960s and 1970s. Experience gained in building and operating the single-shell containments was used in enhancing the design and construction of the double-shell structures. Currently, there are about 250 underground single-shell and double-shell structures containing the high-level waste with an inventory of about 800 million curies. During their service lives, especially in early stages, these structures were subjected to thermal excursions of varying extents; also, they have aged in the chemical environment. Furthermore, in their remaining service lives, the structures may be subjected to loads for which they were not designed, such as larger earthquakes or chemical explosions. As a result, the demonstration of safety of these underground nuclear containments poses a challenge to structural engineers, which increases with time. Regardless of current plans for gradual retrieval of the waste and subsequent solidification for disposal, many of these structures are expected to continue to contain the waste through the next 20-40 years. In order to verify their structural capabilities in fulfilling this mission, several studies were recently performed at Brookhaven National Laboratory

  19. Underground space planning in Helsinki

    Ilkka Vähäaho

    2014-01-01

    This paper gives insight into the use of underground space in Helsinki, Finland. The city has an underground master plan (UMP) for its whole municipal area, not only for certain parts of the city. Further, the decision-making history of the UMP is described step-by-step. Some examples of underground space use in other cities are also given. The focus of this paper is on the sustainability issues related to urban underground space use, including its contribution to an environmentally sustainab...

  20. Regulated underground storage tanks

    This guidance package is designed to assist DOE Field operations by providing thorough guidance on the underground storage tank (UST) regulations. [40 CFR 280]. The guidance uses tables, flowcharts, and checklists to provide a ''roadmap'' for DOE staff who are responsible for supervising UST operations. This package is tailored to address the issues facing DOE facilities. DOE staff should use this guidance as: An overview of the regulations for UST installation and operation; a comprehensive step-by-step guidance for the process of owning and operating an UST, from installation to closure; and a quick, ready-reference guide for any specific topic concerning UST ownership or operation

  1. Dossier: underground storage

    This dossier reviews the main concepts of storage in geologic formations: shape of artificial cavities; natural reservoirs: natural gas storage in aquifers, heat storage, karsts and caves; artificial reservoirs: salt dissolution cavities, salt mines, enlargement of cavities, storage of metal wastes; reservoirs in mining cavities: hydrocarbons storage (tightness, steel coated cavities), cryogenic storage; use of ancient infrastructures (mines, quarries, galleries): hydrocarbons storage, toxic wastes storage, radioactive wastes disposal, reversible radioactive wastes storage, solar neutrons trapping in underground galleries, storage of film archives etc.. (J.S.)

  2. Underground engineering applications

    Developments of any underground engineering application utilizing nuclear explosives involve answering the same questions one encounters in any new area of technology: What are the characteristics of the new tool? How is it applicable to the job to be done? Is it safe to use? and, most importantly, is its use economically acceptable? The many facets of the answers to these questions will be explored. The general types of application presently under consideration will also be reviewed, with particular emphasis on those specific projects actively being worked on by commercial interests and by the U.S. Atomic Energy Commission. (author)

  3. Sanford Underground Research Facility - The United State's Deep Underground Research Facility

    Vardiman, D.

    2012-12-01

    The 2.5 km deep Sanford Underground Research Facility (SURF) is managed by the South Dakota Science and Technology Authority (SDSTA) at the former Homestake Mine site in Lead, South Dakota. The US Department of Energy currently supports the development of the facility using a phased approach for underground deployment of experiments as they obtain an advanced design stage. The geology of the Sanford Laboratory site has been studied during the 125 years of operations at the Homestake Mine and more recently as part of the preliminary geotechnical site investigations for the NSF's Deep Underground Science and Engineering Laboratory project. The overall geology at DUSEL is a well-defined stratigraphic sequence of schist and phyllites. The three major Proterozoic units encountered in the underground consist of interbedded schist, metasediments, and amphibolite schist which are crosscut by Tertiary rhyolite dikes. Preliminary geotechnical site investigations included drift mapping, borehole drilling, borehole televiewing, in-situ stress analysis, laboratory analysis of core, mapping and laser scanning of new excavations, modeling and analysis of all geotechnical information. The investigation was focused upon the determination if the proposed site rock mass could support the world's largest (66 meter diameter) deep underground excavation. While the DUSEL project has subsequently been significantly modified, these data are still available to provide a baseline of the ground conditions which may be judiciously extrapolated throughout the entire Proterozoic rock assemblage for future excavations. Recommendations for facility instrumentation and monitoring were included in the preliminary design of the DUSEL project design and include; single and multiple point extensometers, tape extensometers and convergence measurements (pins), load cells and pressure cells, smart cables, inclinometers/Tiltmeters, Piezometers, thermistors, seismographs and accelerometers, scanners (laser

  4. 30 CFR 75.343 - Underground shops.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground shops. 75.343 Section 75.343... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.343 Underground shops. (a) Underground...-3 through § 75.1107-16, or be enclosed in a noncombustible structure or area. (b) Underground...

  5. Multinational underground nuclear parks

    Newcomer countries expected to develop new nuclear power programs by 2030 are being encouraged by the International Atomic Energy Agency to explore the use of shared facilities for spent fuel storage and geologic disposal. Multinational underground nuclear parks (M-UNPs) are an option for sharing such facilities. Newcomer countries with suitable bedrock conditions could volunteer to host M-UNPs. M-UNPs would include back-end fuel cycle facilities, in open or closed fuel cycle configurations, with sufficient capacity to enable M-UNP host countries to provide for-fee waste management services to partner countries, and to manage waste from the M-UNP power reactors. M-UNP potential advantages include: the option for decades of spent fuel storage; fuel-cycle policy flexibility; increased proliferation resistance; high margin of physical security against attack; and high margin of containment capability in the event of beyond-design-basis accidents, thereby reducing the risk of Fukushima-like radiological contamination of surface lands. A hypothetical M-UNP in crystalline rock with facilities for small modular reactors, spent fuel storage, reprocessing, and geologic disposal is described using a room-and-pillar reference-design cavern. Underground construction cost is judged tractable through use of modern excavation technology and careful site selection. (authors)

  6. RP delves underground

    Anaïs Schaeffer

    2011-01-01

    The LHC’s winter technical stop is rapidly approaching. As in past years, technical staff in their thousands will be flocking to the underground areas of the LHC and the Linac2, Booster, PS and SPS injectors. To make sure they are protected from ionising radiation, members of the Radiation Protection Group will perform an assessment of the levels of radioactivity in the tunnels as soon as the beams have stopped.   Members of the Radiation Protection Group with their precision instruments that measure radioactivity. At 7-00 a.m. on 8 December the LHC and all of the upstream accelerators will begin their technical stop. At 7-30 a.m., members of the Radiation Protection Group will enter the tunnel to perform a radiation mapping, necessary so that the numerous teams can do their work in complete safety. “Before we proceed underground, we always check first to make sure that the readings from the induced radioactivity monitors installed in the tunnels are all normal,&rdqu...

  7. Going Underground in Singapore

    John Osborne (GS/SEM)

    2010-01-01

    Singapore has plans to build a massive Underground Science City (USC) housing R&D laboratories and IT data centres. A delegation involved in the planning to build the subterranean complex visited CERN on 18 October 2010 to learn from civil engineers and safety experts about how CERN plans and constructs its underground facilities.   The delegation from Singapore. The various bodies and corporations working on the USC project are currently studying the feasibility of constructing up to 40 caverns (60 m below ground) similar in size to an LHC experiment hall, in a similar type of rock. Civil engineering and geotechnical experts are calculating the maximum size of the cavern complex that can be safely built. The complex could one day accommodate between 3000 and 5000 workers on a daily basis, so typical issues of size and number of access shafts need to be carefully studied. At first glance, you might not think the LHC has much in common with the USC project; as Rolf Heuer pointed out: &ldq...

  8. Multinational underground nuclear parks

    Myers, C.W. [Nuclear Engineering and Nonproliferation Division, Los Alamos National Laboratory, MS F650, Los Alamos, NM 87544 (United States); Giraud, K.M. [Wolf Creek Nuclear Operating Corporation, 1550 Oxen Lane NE, P.O. Box 411, Burlington, KS 66839-0411 (United States)

    2013-07-01

    Newcomer countries expected to develop new nuclear power programs by 2030 are being encouraged by the International Atomic Energy Agency to explore the use of shared facilities for spent fuel storage and geologic disposal. Multinational underground nuclear parks (M-UNPs) are an option for sharing such facilities. Newcomer countries with suitable bedrock conditions could volunteer to host M-UNPs. M-UNPs would include back-end fuel cycle facilities, in open or closed fuel cycle configurations, with sufficient capacity to enable M-UNP host countries to provide for-fee waste management services to partner countries, and to manage waste from the M-UNP power reactors. M-UNP potential advantages include: the option for decades of spent fuel storage; fuel-cycle policy flexibility; increased proliferation resistance; high margin of physical security against attack; and high margin of containment capability in the event of beyond-design-basis accidents, thereby reducing the risk of Fukushima-like radiological contamination of surface lands. A hypothetical M-UNP in crystalline rock with facilities for small modular reactors, spent fuel storage, reprocessing, and geologic disposal is described using a room-and-pillar reference-design cavern. Underground construction cost is judged tractable through use of modern excavation technology and careful site selection. (authors)

  9. Understanding Electrical Treeing Phenomena in XLPE Cable Insulation Adopting UHF Technique

    Sarathi, Ramanujam; Nandini, Arya; Danikas, Michael G.

    2011-03-01

    A major cause for failure of underground cables is due to formation of electrical trees in the cable insulation. A variety of tree structure can form from a defect site in cable insulation viz bush-type trees, tree-like trees, fibrillar type trees, intrinsic type, depending on the applied voltage. Weibull studies indicate that a higher applied voltage enhances the rate of tree propagation thereby reducing the life of cable insulation. Measurements of injected current during tree propagation indicates that the rise time and fall time of the signal is of few nano seconds. In the present study, an attempt has been made to identify the partial discharges caused due to inception and propagation of electrical trees adopting UHF technique. It is realized that UHF signal generated during tree growth have signal bandwidth in the range of 0.5-2.0 GHz. The formation of streamer type discharge and Townsend type discharges during tree inception and propagation alters the shape of the tree formed. The UHF signal generated due to partial discharges formed during tree growth were analyzed adopting Ternary plot, which can allow one to classify the shape of tree structure formed.

  10. Modern geodesy approach in underground mining

    Mijalkovski, Stojance; Despodov, Zoran; Gorgievski, Cvetan; Bogdanovski, Goran; Mirakovski, Dejan; Hadzi-Nikolova, Marija; Doneva, Nikolinka

    2013-01-01

    This paper presents overview of the development of modern geodesy approach in underground mining. Correct surveying measurements have great importance in mining, especially underground mining as well as a major impact on safety in the development of underground mining facilities.

  11. New Projects in Underground Physics

    Goodman, Maury

    2003-01-01

    A large fraction of neutrino research is taking place in facilities underground. In this paper, I review the underground facilities for neutrino research. I discuss ideas for future reactor experiments being considered to measure theta_13 and the UNO proton decay project.

  12. HAWAII LEAKING UNDERGROUND STORAGE TANKS

    Point coverage of leaking underground storage tanks(LUST) for the state of Hawaii. The original database was developed and is maintained by the State of Hawaii, Dept. of Health. The point locations represent facilities where one or more leaking underground storage tank exists. ...

  13. Radar polarimetry applied to the classification of underground targets

    Moriyama, Toshifumi; Nakamura, Masafumi; Yamaguchi, Yoshio; Yamada, Hiroyoshi; Boerner, Wolfgang-Martin

    1997-12-01

    This paper discusses the classification of target buried in the underground by the radar polarimetry. The subsurface radar is used in the detection of objects buried beneath the ground surface, such as archeological exploration, pipes, gas cables and cavities. However, in addition to target echo, the subsurface radar receives various echoes including clutter, because the underground is inhomogeneous medium. Therefore, the subsurface radar needs the ability to distinguish these echoes. In order to enhance the ability, we first applied the polarization anisotropy coefficient to classify the echo into isotropic target (plate, sphere) and anisotropic target (wire, pipe). It is easy to find the man- made target buried in the underground by polarization anisotropy coefficient. Second, we used a three-component decomposition technique for a scattering matrix. Third, we tried to classify targets using polarimetric signature approach. Moreover, the characteristic polarization state gives the oriented angle of anisotropic target. Therefore, these values contribute the classification of the target. The field experiments using an FM-CW radar system were carried out to show the usefulness of the radar polarimetry. In this paper, several detection and classification results are displayed. It is shown that these techniques improve the detection capability of buried target.

  14. Local Government Uses of Cable Television.

    Cable Television Information Center, Washington, DC.

    The local government cable access channel is essentially a television station completely controlled by the local government. It differs from a local broadcast television station by being able to reach only those places which are connected to the cable system, having much less programming distribution costs, and having the capacity to deliver…

  15. Assessment of sodium conductor distribution cable

    None

    1979-06-01

    The study assesses the barriers and incentives for using sodium conductor distribution cable. The assessment considers environmental, safety, energy conservation, electrical performance and economic factors. Along with all of these factors considered in the assessment, the sodium distribution cable system is compared to the present day alternative - an aluminum conductor system. (TFD)

  16. 21 CFR 890.1175 - Electrode cable.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrode cable. 890.1175 Section 890.1175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1175 Electrode cable....

  17. 14 CFR 25.689 - Cable systems.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cable systems. 25.689 Section 25.689... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.689 Cable systems. (a... smaller than 1/8 inch in diameter may be used in the aileron, elevator, or rudder systems; and (2)...

  18. Cable Television: Its Urban Context and Programming.

    Warthman, Forrest

    Cable television's future in urban settings is discussed in the context of alternative media capable of serving similar markets with similar programing. In addition to cable television, other transmission networks such as the telephone network, radio and television broadcasting, microwave networks, domestic satellites, and recording media are…

  19. Optical cable fault locating using Brillouin optical time domain reflectometer and cable localized heating method

    A novel optical cable fault location method, which is based on Brillouin optical time domain reflectometer (BOTDR) and cable localized heating, is proposed and demonstrated. In the method, a BOTDR apparatus is used to measure the optical loss and strain distribution along the fiber in an optical cable, and a heating device is used to heat the cable at its certain local site. Actual experimental results make it clear that the proposed method works effectively without complicated calculation. By means of the new method, we have successfully located the optical cable fault in the 60 km optical fiber composite power cable from Shanghai to Shengshi, Zhejiang. A fault location accuracy of 1 meter was achieved. The fault location uncertainty of the new optical cable fault location method is at least one order of magnitude smaller than that of the traditional OTDR method

  20. Optical cable fault locating using Brillouin optical time domain reflectometer and cable localized heating method

    Lu, Y. G.; Zhang, X. P.; Dong, Y. M.; Wang, F.; Liu, Y. H.

    2007-07-01

    A novel optical cable fault location method, which is based on Brillouin optical time domain reflectometer (BOTDR) and cable localized heating, is proposed and demonstrated. In the method, a BOTDR apparatus is used to measure the optical loss and strain distribution along the fiber in an optical cable, and a heating device is used to heat the cable at its certain local site. Actual experimental results make it clear that the proposed method works effectively without complicated calculation. By means of the new method, we have successfully located the optical cable fault in the 60 km optical fiber composite power cable from Shanghai to Shengshi, Zhejiang. A fault location accuracy of 1 meter was achieved. The fault location uncertainty of the new optical cable fault location method is at least one order of magnitude smaller than that of the traditional OTDR method.

  1. Behaviour of electrical cables under fire conditions

    A Fire Probabilistic Safety Assessment - called the Fire PSA - is being carried out by the French Institute of Radiological Protection and Nuclear Safety (IPSN) to be used in the framework of the safety assessment of operating 900 MWe PWRs. The aim of this study is to evaluate the core damage conditional probability which could result from a fire. A fire can induce unavailability of safety equipment, notably damaging electrical cables introducing a significant risk contributor. The purpose of this paper is to present the electrical cable fire tests carried out by IPSN to identify the failure modes and to determine the cable damage criteria. The impact of each kind of cable failure mode and the methodology used to estimate the conditional probability of a failure mode when cable damage occurred is also discussed. (orig.)

  2. Underground space planning in Helsinki

    Ilkka Vähäaho

    2014-10-01

    Full Text Available This paper gives insight into the use of underground space in Helsinki, Finland. The city has an underground master plan (UMP for its whole municipal area, not only for certain parts of the city. Further, the decision-making history of the UMP is described step-by-step. Some examples of underground space use in other cities are also given. The focus of this paper is on the sustainability issues related to urban underground space use, including its contribution to an environmentally sustainable and aesthetically acceptable landscape, anticipated structural longevity and maintaining the opportunity for urban development by future generations. Underground planning enhances overall safety and economy efficiency. The need for underground space use in city areas has grown rapidly since the 21st century; at the same time, the necessity to control construction work has also increased. The UMP of Helsinki reserves designated space for public and private utilities in various underground areas of bedrock over the long term. The plan also provides the framework for managing and controlling the city's underground construction work and allows suitable locations to be allocated for underground facilities. Tampere, the third most populated city in Finland and the biggest inland city in the Nordic countries, is also a good example of a city that is taking steps to utilise underground resources. Oulu, the capital city of northern Finland, has also started to ‘go underground’. An example of the possibility to combine two cities by an 80-km subsea tunnel is also discussed. A new fixed link would generate huge potential for the capital areas of Finland and Estonia to become a real Helsinki-Tallinn twin city.

  3. Underground space planning in Helsinki

    Ilkka Vhaho

    2014-01-01

    This paper gives insight into the use of underground space in Helsinki, Finland. The city has an under-ground master plan (UMP) for its whole municipal area, not only for certain parts of the city. Further, the decision-making history of the UMP is described step-by-step. Some examples of underground space use in other cities are also given. The focus of this paper is on the sustainability issues related to urban underground space use, including its contribution to an environmentally sustainable and aesthetically acceptable landscape, anticipated structural longevity and maintaining the opportunity for urban development by future generations. Underground planning enhances overall safety and economy effi-ciency. The need for underground space use in city areas has grown rapidly since the 21st century;at the same time, the necessity to control construction work has also increased. The UMP of Helsinki reserves designated space for public and private utilities in various underground areas of bedrock over the long term. The plan also provides the framework for managing and controlling the city’s underground con-struction work and allows suitable locations to be allocated for underground facilities. Tampere, the third most populated city in Finland and the biggest inland city in the Nordic countries, is also a good example of a city that is taking steps to utilise underground resources. Oulu, the capital city of northern Finland, has also started to‘go underground’. An example of the possibility to combine two cities by an 80-km subsea tunnel is also discussed. A new fixed link would generate huge potential for the capital areas of Finland and Estonia to become a real Helsinki-Tallinn twin city.

  4. Underground layout tradeoff study

    This report presents the results of a technical and economic comparative study of four alternative underground layouts for a nuclear waste geologic repository in salt. The four alternatives considered in this study are (1) separate areas for spent fuel (SF) and commercial high-level waste (CHLW); (2) panel alternation, in which SF and CHLW are emplaced in adjacent panels of rooms; (3) room alternation, in which SF and CHLW are emplaced in adjacent rooms within each panel; and (4) intimate mixture, in which SF and CHLW are emplaced in random order within each storage room. The study concludes that (1) cost is not an important factor; (2) the separate-areas and intimate-mixture alternatives appear, technically, to be more desirable than the other alternatives; and (3) the selection between the separate-areas and intimate mixture alternatives depends upon future resolution of site-specific and reprocessing questions. 5 refs., 6 figs., 12 tabs

  5. Biofuel goes underground

    Tollinsky, Norm

    2011-09-15

    Kirkland Lake Gold, a gold producer, is switching to a blend of biofuel to power the mine's underground equipment. Kirkland Lake Gold is using a soy-based product which has several advantages: less expensive: for example, the soybean-based biofuel used by Kirkland Lake Gold is 10 cents a liter less expensive than diesel; cleaner: biofuel can reduce emissions by up to 80 per cent compared to conventional diesel; and safer: biofuel is safer than miner's diesel because it has a much higher flash point. Testing with soybean-based biofuel began in the early 90s but its price was too high at that time. The federal government's regulation of renewable fuel quotas has led to the better availability of biofuel now. The supply should be doubled to meet government quotas.

  6. ACAC Converters for UPS

    Rusalin Lucian R. Păun

    2008-05-01

    Full Text Available This paper propose a new control technique forsingle – phase ACAC converters used for a on-line UPSwith a good dynamic response, a reduced-partscomponents, a good output characteristic, a good powerfactorcorrection(PFC. This converter no needs anisolation transformer. A power factor correction rectifierand an inverter with the proposed control scheme has beendesigned and simulated using Caspoc2007, validating theconcept.

  7. Construction behavior of the first underground opening of the superconducting super collider project

    Most underground structures of the Superconducting Super Collider (SSC) will be within the competent Austin Chalk (AC), an ideal tunneling medium; however, some structures will be within the very low strength Eagle Ford Shale (EFS). A 3 m diameter Exploratory Shaft, 82 m deep with a test adit at the AC/EFS contact was constructed as the first underground opening on the SSC to provide information on design parameters and construction behavior. The Exploratory Shaft was instrumented with piezometers, MPBXs, convergence anchors, inclinometer and heave gage casings, and an instrumented steel ring liner section. The shaft was deep enough to induce over-stress in the EFS. The geomechanical properties of the EFS and overlying AC, the instrumentation, and the insights gained for the SSC project are presented in this paper

  8. Magnetic flux leakage-based steel cable NDE and damage visualization on a cable climbing robot

    Kim, Ju-Won; Lee, Changgil; Park, Seunghee; Lee, Jong Jae

    2012-04-01

    The steel cables in long span bridges such as cable-stayed bridges and suspension bridges are critical members which suspend the load of main girders and bridge floor slabs. Damage of cable members can occur in the form of crosssectional loss caused by fatigue, wear, and fracture, which can lead to structural failure due to concentrated stress in the cable. Therefore, nondestructive examination of steel cables is necessary so that the cross-sectional loss can be detected. Thus, an automated cable monitoring system using a suitable NDE technique and a cable climbing robot is proposed. In this study, an MFL (Magnetic Flux Leakage- based inspection system was applied to monitor the condition of cables. This inspection system measures magnetic flux to detect the local faults (LF) of steel cable. To verify the feasibility of the proposed damage detection technique, an 8-channel MFL sensor head prototype was designed and fabricated. A steel cable bunch specimen with several types of damage was fabricated and scanned by the MFL sensor head to measure the magnetic flux density of the specimen. To interpret the condition of the steel cable, magnetic flux signals were used to determine the locations of the flaws and the level of damage. Measured signals from the damaged specimen were compared with thresholds set for objective decision making. In addition, the measured magnetic flux signal was visualized into a 3D MFL map for convenient cable monitoring. Finally, the results were compared with information on actual inflicted damages to confirm the accuracy and effectiveness of the proposed cable monitoring method.

  9. Non-cable vehicle guidance

    Daugela, G.C.; Willott, A.M.; Chopiuk, R.G.; Thornton, S.E.

    1988-06-01

    The purpose is to determine the most promising driverless mine vehicle guidance systems that are not dependent on buried cables, and to plan their development. The project is presented in two phases: a preliminary study and literature review to determine whether suitable technologies exist to justify further work; and an in-depth assessment and selection of technologies for vehicle guidance. A large number of guidance elements are involved in a completely automated vehicle. The technologies that hold the best potential for development of guidance systems for mine vehicles are ultrasonics, radar, lasers, dead reckoning, and guidance algorithms. The best approach to adaptation of these technologies is on a step by step basis. Guidance modules that are complete in themselves and are designed to be integrated with other modules can provide short term benefits. Two modules are selected for development: the dragline operations monitor and automated machine control for optimized mining (AMCOM). 99 refs., 20 figs., 40 tabs.

  10. Self-healing cable for extreme environments

    Huston, Dryver R. (Inventor); Tolmie, Bernard R. (Inventor)

    2009-01-01

    Self-healing cable apparatus and methods disclosed. The self-healing cable has a central core surrounded by an adaptive cover that can extend over the entire length of the self-healing cable or just one or more portions of the self-healing cable. The adaptive cover includes an axially and/or radially compressible-expandable (C/E) foam layer that maintains its properties over a wide range of environmental conditions. A tape layer surrounds the C/E layer and is applied so that it surrounds and axially and/or radially compresses the C/E layer. When the self-healing cable is subjected to a damaging force that causes a breach in the outer jacket and the tape layer, the corresponding localized axially and/or radially compressed portion of the C/E foam layer expands into the breach to form a corresponding localized self-healed region. The self-healing cable is manufacturable with present-day commercial self-healing cable manufacturing tools.

  11. Power plant practices to ensure cable operability

    This report describes the design, installation, qualification, maintenance, and testing of nuclear power plant cables with regard to continued operability. The report was initiated after questions arose concerning inadvertent abuse of cables during installation at two nuclear power plants. The extent of the damage was not clear and there was a concern as to whether cables, if damaged, would be able to function under accident conditions. This report reviews and discusses installation practices in the industry. The report also discusses currently available troubleshooting and in-situ testing techniques and provides cautions for some cases which may lead to further cable damage. Improved troubleshooting techniques currently under development are also discussed. These techniques may reduce the difficulty of testing while being able to identify cable flaws more definitively. The report finds, in general, that nuclear power plant cables have been relatively trouble-free; however, there is a need for further research and development of troubleshooting techniques which will make cable condition testing easier and more reliable. Also, recommendations for ''good'' installation practices are needed

  12. The effect of DC superimposed AC Voltage on Partial Discharges in Dielectric Bounded Cavities

    Olsen, Pål Keim; Mauseth, Frank; Ildstad, Erling

    2014-01-01

    Voltage source converters is used in HVDC stations in offshore HVDC transmission systems, between the AC and DC power grid. The AC ripple voltage on the DC side of the HVDC stations can be in the range of 1-10 % of the nominal DC voltage, depending on the size of the filter employed. For offshore HVDC grids, there is a drive to use polymeric insulated cables on the DC side. This work investigates how an AC voltage at power frequency superimposed on DC voltage influence the partial discharge m...

  13. 47 CFR 32.2424 - Submarine & deep sea cable.

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic...

  14. Basic cable routing guidelines for a fast reactor plant

    In this paper the guidelines evolved for cable routing in 500 MWe Prototype Fast Breeder Reactor (PFBR) are presented. Safety related redundant system cables in a nuclear plant shall not become unavailable due to cable fire. This is ensured by proper cable routing in the plant in addition to the other general fire protection measures

  15. Cable Television 1980: Status and Prospect for Higher Education.

    Baus, F., Ed.

    Baseline information for the would-be cable television educational programer is provided by two papers, one an overview of the state of the cable television industry, and the other a report on a marketing study conducted to determine consumer attitudes toward cable TV as an educational medium. In "The Promise and Reality of Cable Television,"…

  16. The creation of high-temperature superconducting cables of megawatt range in Russia

    Sytnikov, V. E.; Bemert, S. E.; Krivetsky, I. V.; Romashov, M. A.; Popov, D. A.; Fedotov, E. V.; Komandenko, O. V.

    2015-12-01

    Urgent problems of the power industry in the 21st century require the creation of smart energy systems, providing a high effectiveness of generation, transmission, and consumption of electric power. Simultaneously, the requirements for controllability of power systems and ecological and resource-saving characteristics at all stages of production and distribution of electric power are increased. One of the decision methods of many problems of the power industry is the development of new high-efficiency electrical equipment for smart power systems based on superconducting technologies to ensure a qualitatively new level of functioning of the electric power industry. The intensive research and development of new types of electrical devices based on superconductors are being carried out in many industrialized advanced countries. Interest in such developments has especially increased in recent years owing to the discovery of so-called high-temperature superconductors (HTS) that do not require complicated and expensive cooling devices. Such devices can operate at cooling by inexpensive and easily accessible liquid nitrogen. Taking into account the obvious advantages of superconducting cable lines for the transmission of large power flows through an electrical network, as compared with conventional cables, the Federal Grid Company of Unified Energy System (JSC FGC UES) initiated a research and development program including the creation of superconducting HTS AC and DC cable lines. Two cable lines for the transmitted power of 50 MVA/MW at 20 kV were manufactured and tested within the framework of the program.

  17. Low coupling loss core-strengthened Bi 2212\\/Ag Rutherford cables

    Collings, E W; Scanlan, R M; Dietderich, D R; Motowidlo, L R

    1999-01-01

    In a comprehensive "vertically integrated" program multifilamentary (MF) high temperature superconducting (HTSC) Bi:2212/Ag strand was fabricated using the powder-in-tube process and heat treated in oxygen by a modified standard $9 procedure. The reaction-heat-treatment (HT) was adjusted to maximize critical current (density), I/sub c/ (J /sub c/), as measured in various magnetic fields, B. A series of Rutherford cables was designed, each of which included a $9 metallic (Nichrome-80) core for strengthening and reduction of coupling loss. Prior to cable winding a series of tests examined the possibility of strand "poisoning" by the core during HT. Small model Rutherford cables were wound, $9 and after HT were prepared for I/sub c/(B) measurement and calorimetric measurement of AC loss and hence interstrand contact resistance I/sub c/(B). It was deduced that, if in direct contact with the strand during HT, the core $9 material can degrade the I/sub c/ of the cable; but steps can be taken to eliminate this probl...

  18. The creation of high-temperature superconducting cables of megawatt range in Russia

    Sytnikov, V. E., E-mail: vsytnikov@gmail.com; Bemert, S. E.; Krivetsky, I. V.; Romashov, M. A. [JSC NTTs FSC EES (Russian Federation); Popov, D. A.; Fedotov, E. V.; Komandenko, O. V. [JSC Irkutskkabel (Russian Federation)

    2015-12-15

    Urgent problems of the power industry in the 21st century require the creation of smart energy systems, providing a high effectiveness of generation, transmission, and consumption of electric power. Simultaneously, the requirements for controllability of power systems and ecological and resource-saving characteristics at all stages of production and distribution of electric power are increased. One of the decision methods of many problems of the power industry is the development of new high-efficiency electrical equipment for smart power systems based on superconducting technologies to ensure a qualitatively new level of functioning of the electric power industry. The intensive research and development of new types of electrical devices based on superconductors are being carried out in many industrialized advanced countries. Interest in such developments has especially increased in recent years owing to the discovery of so-called high-temperature superconductors (HTS) that do not require complicated and expensive cooling devices. Such devices can operate at cooling by inexpensive and easily accessible liquid nitrogen. Taking into account the obvious advantages of superconducting cable lines for the transmission of large power flows through an electrical network, as compared with conventional cables, the Federal Grid Company of Unified Energy System (JSC FGC UES) initiated a research and development program including the creation of superconducting HTS AC and DC cable lines. Two cable lines for the transmitted power of 50 MVA/MW at 20 kV were manufactured and tested within the framework of the program.

  19. A unique cabling machine designed to produce rutherford-type superconducting cable for the SSC project

    Up to 25,000 Km of keystoned flat cable must be produced for the SSC project. Starting from a specification developed by Lawrence Berkeley Laboratory (LBL), a special cabling machine has been designed by Dour Metal. It has been designed to be able to run at a speed corresponding to a maximum production rate of 10 m/min. This cabling machine is the key part of the production line which consists of a precision Turkshead equipped with a variable power drive, a caterpillar, a dimensional control bench, a data acquisition system, and a take-up unit. The main features of the cabling unit to be described are a design with nearly equal path length between spool and assembling point for all the wires, and the possibility to run the machine with several over- or under-twisting ratios between cable and wires. These requirements led Dour Metal to the choice of an unconventional mechanical concept for a cabling machine

  20. 29 CFR 1926.956 - Underground lines.

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Underground lines. 1926.956 Section 1926.956 Labor... Underground lines. (a) Guarding and ventilating street opening used for access to underground lines or... underground facilities, efforts shall be made to determine the location of such facilities and work...

  1. Environmental benefits of underground coal gasification.

    Liu, Shu-qin; Liu, Jun-hua; Yu, Li

    2002-04-01

    Environmental benefits of underground coal gasification are evaluated. The results showed that through underground coal gasification, gangue discharge is eliminated, sulfur emission is reduced, and the amount of ash, mercury, and tar discharge are decreased. Moreover, effect of underground gasification on underground water is analyzed and CO2 disposal method is put forward. PMID:12046301

  2. Underground storage of radioactive wastes

    An introductory survey of the underground disposal of radioactive wastes is given. Attention is paid to various types of radioactive wastes varying from low to highly active materials, as well as mining techniques and salt deposits

  3. Arrival directions of underground muons

    A geiger counter cosmic ray telescope has been constructed in the Holborn Underground Laboratory, London, to study the arrival directions of cosmic ray muons in the zenith angle range 70 - 900. The apparatus is described and some preliminary results presented

  4. ATLAS solenoid operates underground

    2006-01-01

    A new phase for the ATLAS collaboration started with the first operation of a completed sub-system: the Central Solenoid. Teams monitoring the cooling and powering of the ATLAS solenoid in the control room. The solenoid was cooled down to 4.5 K from 17 to 23 May. The first current was established the same evening that the solenoid became cold and superconductive. 'This makes the ATLAS Central Solenoid the very first cold and superconducting magnet to be operated in the LHC underground areas!', said Takahiko Kondo, professor at KEK. Though the current was limited to 1 kA, the cool-down and powering of the solenoid was a major milestone for all of the control, cryogenic, power and vacuum systems-a milestone reached by the hard work and many long evenings invested by various teams from ATLAS, all of CERN's departments and several large and small companies. Since the Central Solenoid and the barrel liquid argon (LAr) calorimeter share the same cryostat vacuum vessel, this achievement was only possible in perfe...

  5. Underground pumped hydroelectric storage

    Allen, R.D.; Doherty, T.J.; Kannberg, L.D.

    1984-07-01

    Underground pumped hydroelectric energy storage was conceived as a modification of surface pumped storage to eliminate dependence upon fortuitous topography, provide higher hydraulic heads, and reduce environmental concerns. A UPHS plant offers substantial savings in investment cost over coal-fired cycling plants and savings in system production costs over gas turbines. Potential location near load centers lowers transmission costs and line losses. Environmental impact is less than that for a coal-fired cycling plant. The inherent benefits include those of all pumped storage (i.e., rapid load response, emergency capacity, improvement in efficiency as pumps improve, and capacity for voltage regulation). A UPHS plant would be powered by either a coal-fired or nuclear baseload plant. The economic capacity of a UPHS plant would be in the range of 1000 to 3000 MW. This storage level is compatible with the load-leveling requirements of a greater metropolitan area with population of 1 million or more. The technical feasibility of UPHS depends upon excavation of a subterranean powerhouse cavern and reservoir caverns within a competent, impervious rock formation, and upon selection of reliable and efficient turbomachinery - pump-turbines and motor-generators - all remotely operable.

  6. LUNA: Nuclear Astrophysics Deep Underground

    Broggini, Carlo; Bemmerer, Daniel; Guglielmetti, Alessandra; Menegazzo, Roberto

    2010-01-01

    Nuclear astrophysics strives for a comprehensive picture of the nuclear reactions responsible for synthesizing the chemical elements and for powering the stellar evolution engine. Deep underground in the Gran Sasso laboratory the cross sections of the key reactions of the proton-proton chain and of the Carbon-Nitrogen-Oxygen (CNO) cycle have been measured right down to the energies of astrophysical interest. The salient features of underground nuclear astrophysics are summarized here. The mai...

  7. Parametrically excited oscillation of stay cable and its control in cable-stayed bridges

    孙炳楠; 汪至刚; 高赞明; 倪一清

    2003-01-01

    This paper presents a nonlinear dynamic model for simulation and analysis of a kind of parametrically excited vibration of stay cable caused by support motion in cable-stayed bridges. The sag, inclination angle of the stay cable are considered in the model, based on which, the oscillation mechanism and dynamic response characteristics of this kind of vibration are analyzed through numerical calculation. It is noted that parametrically excited oscillation of a stay cable with certain sag, inclination angle and initial static tension force may occur in cable-stayed bridges due to deck vibration under the condition that the natural frequency of a cable approaches to about half of the first model frequency of the bridge deck system. A new vibration control system installed on the cable anchorage is proposed as a possible damping system to suppress the cable parametric oscillation. The numerical calculation results showed that with the use of this damping system, the cable oscillation due to the vibration of the deck and/or towers will be considerably reduced.

  8. Condition Monitoring of Cables Task 3 Report: Condition Monitoring Techniques for Electric Cables

    Villaran, M.; Lofaro, R.; na

    2009-11-30

    For more than 20 years the NRC has sponsored research studying electric cable aging degradation, condition monitoring, and environmental qualification testing practices for electric cables used in nuclear power plants. This report summarizes several of the most effective and commonly used condition monitoring techniques available to detect damage and measure the extent of degradation in electric cable insulation. The technical basis for each technique is summarized, along with its application, trendability of test data, ease of performing the technique, advantages and limitations, and the usefulness of the test results to characterize and assess the condition of electric cables.

  9. Chinese Market for Fibres and Cables

    Yuxing Zhao

    2003-01-01

    This article presents a summary of Chinese market of optical fibres and cables based on the development of the optical communications industry. Analysis shows that the market will keep growing for sometime in the future.

  10. 3-D Numerical Simulations of Twisted Stacked Tape Cables

    Krüger, Philipp A. C.; Zermeño, Victor M. R.; Takayasu, Makoto; Grilli, Francesco

    2014-01-01

    Different magnet applications require compact high current cables. Among the proposed solutions, the Twisted Stacked Tape Cable (TSTC) is easy to manufacture and has very high tape length usage efficiency. In this kind of cables the tapes are closely packed, so that their electromagnetic interaction is very strong and determines the overall performance of the cable. Numerical models are necessary tools to precisely evaluate this interaction and to predict the cable's behavior, e.g. in terms o...

  11. Experimental Simulation of Wet-Snow Shedding from Sagged Cables

    Fonyó, András; Kollar, László E.; Farzaneh, Masoud; Montpellier, Patrice

    2009-01-01

    The process of wet-snow shedding from overhead cables was simulated in cold-chamber experiments under different ambient conditions. The main objective of the study was to examine how cable sag influences the snow-shedding process. However, the effects of several other parameters were also considered, such as air temperature, solar radiation, snow-sleeve length, and periodic excitation of the cable. Periodic excitation was applied at the suspension point of the cable, leading to cable vibratio...

  12. High frequency characteristics of medium voltage XLPE power cables

    Mugala, Gavita

    2005-01-01

    The response of a cable can be used to analyze the variation of the material characteristics along its length. For diagnosis of possible ageing, it is necessary to know how cable design, material properties and cable insulation ageing affects the wave propagation. A cable model has therefore been worked out based upon the high frequency properties of the cable insulation and conductor systems. The high frequency characteristics of the semi-conducting screens, new and water-tree aged cross-lin...

  13. Sustainable underground space development in Hong Kong

    Xu, Xiaoxiao; 徐笑晓

    2014-01-01

    Underground space development is regarded as an effective approach to promote a quality living environment in compact city. In Hong Kong, urban underground space developed by private sectors seems not well organized. Besides, underground use in HK can be multifunctional. Thirdly, inner design in some underground spaces is not desirable and lacks vibrancy. Fourthly, underground space development in HK lacks governmental incentives. Last but not least, the regulations and legal loophole on prop...

  14. Electrical Cable Bacteria Save Marine Life

    Nielsen, Lars Peter

    2016-01-01

    Animals at the bottomof the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron ‘carpet’, trapping toxic hydrogen sulfide.......Animals at the bottomof the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron ‘carpet’, trapping toxic hydrogen sulfide....

  15. Cable system transients theory, modeling and simulation

    Ametani, Akihiro; Nagaoka, Naoto

    2015-01-01

    A systematic and comprehensive introduction to electromagnetic transient in cable systems, written by the internationally renowned pioneer in this field Presents a systematic and comprehensive introduction to electromagnetic transient in cable systems Written by the internationally renowned pioneer in the field Thorough coverage of the state of the art on the topic, presented in a well-organized, logical style, from fundamentals and practical applications A companion website is available

  16. Ecology: Electrical Cable Bacteria Save Marine Life

    Nielsen, Lars Peter

    2016-01-01

    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide.......Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide....

  17. Characteristic analysis of DC electric railway systems with superconducting power cables connecting power substations

    The application of superconducting power cables to DC electric railway systems has been studied. It could leads to an effective use of regenerative brake, improved energy efficiency, effective load sharing among the substations, etc. In this study, an electric circuit model of a DC feeding system is built and numerical simulation is carried out using MATLAB-Simulink software. A modified electric circuit model with an AC power grid connection taken into account is also created to simulate the influence of the grid connection. The analyses have proved that a certain amount of energy can be conserved by introducing superconducting cables, and that electric load distribution and concentration among the substations depend on the substation output voltage distribution.

  18. Specialized video systems for use in underground storage tanks

    The Robotics Development Groups at the Savannah River Site and the Hanford site have developed remote video and photography systems for deployment in underground radioactive waste storage tanks at Department of Energy (DOE) sites as a part of the Office of Technology Development (OTD) program within DOE. Figure 1 shows the remote video/photography systems in a typical underground storage tank environment. Viewing and documenting the tank interiors and their associated annular spaces is an extremely valuable tool in characterizing their condition and contents and in controlling their remediation. Several specialized video/photography systems and robotic End Effectors have been fabricated that provide remote viewing and lighting. All are remotely deployable into and from the tank, and all viewing functions are remotely operated. Positioning all control components away from the facility prevents the potential for personnel exposure to radiation and contamination. Overview video systems, both monaural and stereo versions, include a camera, zoom lens, camera positioner, vertical deployment system, and positional feedback. Each independent video package can be inserted through a 100 mm (4 in.) diameter opening. A special attribute of these packages is their design to never get larger than the entry hole during operation and to be fully retrievable. The End Effector systems will be deployed on the large robotic Light Duty Utility Arm (LDUA) being developed by other portions of the OTD-DOE programs. The systems implement a multi-functional ''over the coax'' design that uses a single coaxial cable for all data and control signals over the more than 900 foot cable (or fiber optic) link

  19. Carbon Fiber Reinforced Polymer for Cable Structures—A Review

    Yue Liu

    2015-10-01

    Full Text Available Carbon Fiber Reinforced Polymer (CFRP is an advanced composite material with the advantages of high strength, lightweight, no corrosion and excellent fatigue resistance. Therefore, unidirectional CFRP has great potential for cables and to replace steel cables in cable structures. However, CFRP is a typical orthotropic material and its strength and modulus perpendicular to the fiber direction are much lower than those in the fiber direction, which brings a challenge for anchoring CFRP cables. This paper presents an overview of application of CFRP cables in cable structures, including historical review, state of the art and prospects for the future. After introducing properties of carbon fibers, mechanical characteristics and structural forms of CFRP cables, existing CFRP cable structures in the world (all of them are cable bridges are reviewed. Especially, their CFRP cable anchorages are presented in detail. New applications for CFRP cables, i.e., cable roofs and cable facades, are also presented, including the introduction of a prototype CFRP cable roof and the conceptual design of a novel structure—CFRP Continuous Band Winding System. In addition, other challenges that impede widespread application of CFRP cable structures are briefly introduced.

  20. Environmental assessment of submarine power cables

    Extensive analyses conducted by the European Community revealed that offshore wind energy have relatively benign effects on the marine environment by comparison to other forms of electric power generation [1]. However, the materials employed in offshore wind power farms suffer major changes to be confined to the marine environment at extreme conditions: saline medium, hydrostatic pressure... which can produce an important corrosion effect. This phenomenon can affect on the one hand, to the material from the structural viewpoint and on the other hand, to the marine environment. In this sense, to better understand the environmental impacts of generating electricity from offshore wind energy, this study evaluated the life cycle assessment for some new designs of submarine power cables developed by General Cable. To achieve this goal, three approaches have been carried out: leaching tests, eco-toxicity tests and Life Cycle Assessment (LCA) methodologies. All of them are aimed to obtaining quantitative data for environmental assessment of selected submarine cables. LCA is a method used to assess environmental aspects and potential impacts of a product or activity. LCA does not include financial and social factors, which means that the results of an LCA cannot exclusively form the basis for assessment of a product's sustainability. Leaching tests results allowed to conclude that pH of seawater did not significantly changed by the presence of submarine three-core cables. Although, it was slightly higher in case of broken cable, pH values were nearly equals. Concerning to the heavy metals which could migrate to the aquatic medium, there were significant differences in both scenarios. The leaching of zinc is the major environmental concern during undersea operation of undamaged cables whereas the fully sectioned three-core cable produced the migration of significant quantities of copper and iron apart from the zinc migrated from the galvanized steel. Thus, the tar

  1. Environmental assessment of submarine power cables

    Isus, Daniel; Martinez, Juan D. [Grupo General Cable Sistemas, S.A., 08560-Manlleu, Barcelona (Spain); Arteche, Amaya; Del Rio, Carmen; Madina, Virginia [Tecnalia Research and Innovation, 20009 San Sebastian (Spain)

    2011-03-15

    Extensive analyses conducted by the European Community revealed that offshore wind energy have relatively benign effects on the marine environment by comparison to other forms of electric power generation [1]. However, the materials employed in offshore wind power farms suffer major changes to be confined to the marine environment at extreme conditions: saline medium, hydrostatic pressure... which can produce an important corrosion effect. This phenomenon can affect on the one hand, to the material from the structural viewpoint and on the other hand, to the marine environment. In this sense, to better understand the environmental impacts of generating electricity from offshore wind energy, this study evaluated the life cycle assessment for some new designs of submarine power cables developed by General Cable. To achieve this goal, three approaches have been carried out: leaching tests, eco-toxicity tests and Life Cycle Assessment (LCA) methodologies. All of them are aimed to obtaining quantitative data for environmental assessment of selected submarine cables. LCA is a method used to assess environmental aspects and potential impacts of a product or activity. LCA does not include financial and social factors, which means that the results of an LCA cannot exclusively form the basis for assessment of a product's sustainability. Leaching tests results allowed to conclude that pH of seawater did not significantly changed by the presence of submarine three-core cables. Although, it was slightly higher in case of broken cable, pH values were nearly equals. Concerning to the heavy metals which could migrate to the aquatic medium, there were significant differences in both scenarios. The leaching of zinc is the major environmental concern during undersea operation of undamaged cables whereas the fully sectioned three-core cable produced the migration of significant quantities of copper and iron apart from the zinc migrated from the galvanized steel. Thus, the tar

  2. A New Coordinated Voltage Control Scheme for Offshore AC Grid of HVDC Connected Offshore Wind Power Plants

    Sakamuri, Jayachandra N.; Nicolaos Antonio CUTULULIS; Rather, Zakir Hussain; Rimez, Johan

    2015-01-01

    This paper proposes a coordinated voltage control scheme (CVCS) which enhances the voltage ride through (VRT) capability of an offshore AC grid comprised of a cluster of offshore wind power plants (WPP) connected through AC cables to the offshore voltage source converter based high voltage DC (VSC-HVDC) converter station. Due to limited short circuit power contribution from power electronic interfaced variable speed wind generators and with the onshore main grid decoupled by the HVDC link, th...

  3. AC power supply systems

    An ac power supply system includes a rectifier fed by a normal ac supply, and an inverter connected to the rectifier by a dc link, the inverter being effective to invert the dc output of the receiver at a required frequency to provide an ac output. A dc backup power supply of lower voltage than the normal dc output of the rectifier is connected across the dc link such that the ac output of the rectifier is derived from the backup supply if the voltage of the output of the inverter falls below that of the backup supply. The dc backup power may be derived from a backup ac supply. Use in pumping coolant in nuclear reactor is envisaged. (author)

  4. Measurement of AC losses in different former materials

    Olsen, Søren Krüger; Træholt, Chresten; Kühle, Anders Van Der Aa;

    1998-01-01

    A high temperature superconducting cable may be based on a centrally located cylindrical support, a so-called former. If electrically conductive, the former can contribute to the AC losses through eddy current losses caused by unbalanced axial and tangential magnetic fields. With these measurements...... we aim at investigating the eddy current losses of commonly used former materials. A one layer cable conductor was wound on a glass fibre reinforced polymer (GRFP) former. By inserting a variety of materials into this, it was possible to measure the eddy current losses of each of the former...... candidates separately; for example copper tubes, stainless steel braid, copper braid, corrugated stainless steel tubes, etc. The measured data are compared with the predictions of a theoretical model. Our results show that in most cases, the losses induced by eddy currents in the former are negligible...

  5. Measurement of AC losses in different former materials

    Olsen, Søren Krüger; Træholt, Chresten; Kühle, Anders Van Der Aa;

    1998-01-01

    candidates separately; for example copper tubes, stainless steel braid, copper braid, corrugated stainless steel tubes, etc. The measured data are compared with the predictions of a theoretical model. Our results show that in most cases, the losses induced by eddy currents in the former are negligible......A high temperature superconducting cable may be based on a centrally located cylindrical support, a so-called former. If electrically conductive, the former can contribute to the AC losses through eddy current losses caused by unbalanced axial and tangential magnetic fields. With these measurements...... we aim at investigating the eddy current losses of commonly used former materials. A one layer cable conductor was wound on a glass fibre reinforced polymer (GRFP) former. By inserting a variety of materials into this, it was possible to measure the eddy current losses of each of the former...

  6. Modelling ac ripple currents in HTS coated conductors

    Xu, Zhihan; Grilli, Francesco

    2015-10-01

    Dc transmission using high temperature superconducting (HTS) coated conductors (CCs) offers a promising solution to the globally growing demand for effective, reliable and economic transmission of green energy up to the gigawatt level over very long distances. The credible estimation of the losses and thereby the heat dissipation involved, where ac ripples (introduced in rectification/ac-dc conversion) are viewed as a potential source of notable contribution, is highly essential for the rational design of practical HTS dc transmission cables and corresponding cryogenic systems to fulfil this demand. Here we report a targeted modelling study into the ac losses in a HTS CC subject to dc and ac ripple currents simultaneously, by solving Maxwell’s equations using the finite element method (FEM) in the commercial software package COMSOL. It is observed that the instantaneous loss exhibits only one peak per cycle in the HTS CC subject to sinusoidal ripples, given that the amplitude of the ac ripples is smaller than approximately 20% of that of the dc current. This is a distinct contrast to the usual observation of two peaks per cycle in a HTS CC subject to ac currents only. The unique mechanism is also revealed, which is directly associated with the finding that, around any local minima of the applied ac ripples, the critical state of -J c is never reached at the edges of the HTS CC, as it should be according to the Bean model. When running further into the longer term, it is discovered that the ac ripple loss of the HTS CC in full-wave rectification decays monotonically, at a speed which is found to be insensitive to the frequency of the applied ripples within our targeted situations, to a relatively low level of approximately 1.38 × 10-4 W m-1 in around 1.7 s. Comparison between this level and other typical loss contributions in a HTS dc cable implies that ac ripple currents in HTS CCs should only be considered as a minor source of dissipation in superconducting dc

  7. Application study on the first cable-stayed bridge with CFRP cables in China

    Kuihua Mei

    2015-08-01

    Full Text Available In order to push forward the development of CFRP cable-stayed bridge and accumulate experiences, the study on the application of the first cable-stayed bridge with CFRP cables in China was carried out. The design essentials of main components of the bridge were introduced and its integral performances, including static properties, dynamic properties and seismic response were analyzed using finite element method. A new bond-type anchorage was developed and the processes of fabricating and installing CFRP cables were elaborated. Based on the results of construction simulation, a tension scheme for bridge was propound. During constructing, the stresses and displacement of girder and pylon, as well as the forces and stresses of cables, were tested. The results indicate that all sections of the bridge could meet the requirements of the ultimate bearing capacity and normal service; the performance of the anchorage is good and the stresses in each cable system are similar; the tested values accord well with the calculated values. Further, creep deformation of the resin in anchorages under service load is not obvious. All these results demonstrate that the first application of CFRP cables in the cable-stayed bridge in China is successful.

  8. Underground disposal of radioactive wastes

    This report is an overview document for the series of IAEA reports dealing with underground waste disposal to be prepared in the next few years. It provides an introduction to the general considerations involved in implementing underground disposal of radioactive wastes. It suggests factors to be taken into account for developing and assessing waste disposal concepts, including the conditioned waste form, the geological containment and possible additional engineered barriers. These guidelines are general so as to cover a broad range of conditions. They are generally applicable to all types of underground disposal, but the emphasis is on disposal in deep geological formations. Some information presented here may require slight modifications when applied to shallow ground disposal or other types of underground disposal. Modifications may also be needed to reflect local conditions. In some specific cases it may be that not all the considerations dealt with in this book are necessary; on the other hand, while most major considerations are believed to be included, they are not meant to be all-inclusive. The book primarily concerns only underground disposal of the wastes from nuclear fuel cycle operations and those which arise from the use of isotopes for medical and research activities

  9. Earthquake observation at underground cavern

    The earthquake observation has been examined at a cylindrical type cavern hydroelectric power station of 15 m in diameter, 22 m in depth in rock mass in purpose of evaluating the earthquake resistance of semi-underground nuclear power plants. The behavior of the cylindrical cavern has been analysed by fourty-three observed seismic waves. And following results were obtained. (1) Ratios of cavern buttom maximum accelerations to cavern top maximum accelerations are concentrated in the range from 1/2 to 1. This shows that the accelerations are declined at underground. (2) The decline ratios of on-ground spectrum amplitude to the underground at the earthquakes of less than 100 km epicentral distance with shorter predominant periods are generally larger than these at the earthquakes of more than 100 km epicentral distance with longer predominant periods. (3) The peak periods of normalized response spectrum at underground tend to be longer as the epicentral distances are longer. This phenominons of underground are similar to the on-ground. (author)

  10. Generalized cable theory for neurons in complex and heterogeneous media

    Bédard, Claude; Destexhe, Alain

    2013-08-01

    Cable theory has been developed over the last decade, usually assuming that the extracellular space around membranes is a perfect resistor. However, extracellular media may display more complex electrical properties due to various phenomena, such as polarization, ionic diffusion, or capacitive effects, but their impact on cable properties is not known. In this paper, we generalize cable theory for membranes embedded in arbitrarily complex extracellular media. We outline the generalized cable equations, then consider specific cases. The simplest case is a resistive medium, in which case the equations recover the traditional cable equations. We show that for more complex media, for example, in the presence of ionic diffusion, the impact on cable properties such as voltage attenuation can be significant. We illustrate this numerically, always by comparing the generalized cable to the traditional cable. We conclude that the nature of intracellular and extracellular media may have a strong influence on cable filtering as well as on the passive integrative properties of neurons.

  11. Cable condition monitoring in a pressurized water reactor environment

    Oconee Nuclear Station is the first nuclear plant designed, engineered and constructed by Duke Power Company. Even though the accelerated aging method was available to determine the life expectancy of the cable used in the reactor building, no natural aging data was available at that time. In order to be able to verify the condition of the reactor building cable over the life of the plant, an on-going cable monitoring plan was instituted. Various types of cable were selected to be monitored, and they were installed in cable life evaluation circuits in the reactor building. At five year intervals over the life of the plant, cable samples would be removed from these cable life evaluation circuits and tested to determine the effects of the reactor building environment on the integrity of the cable. A review of the cable life evaluation circuits and the results of the evaluation program to date is presented

  12. Ship nuclear power device of cable aging management

    Cable for marine nuclear power plant continuous delivery of electrical energy. Cable is mostly in the high temperature and strong radiation and harsh working environment, and can not be replaced in the lifetime This should be the cable aging management methods through research, maintenance and repair program to provide a scientific basis. Cable aging management approach for a number of different levels of cable management at different levels, relying on computers and other modern tools, the use of information management database software maintenance of the cable through the science of aging control. Cable Aging Management including the scope of cable aging management, classification management basis and used for different levels of management supervision and implementation of means testing approach. Application of the ship that has the operational management science, both planned maintenance to improve the science, but also improves the efficiency of aging management. This management method can be extended to nuclear power plants of cable aging management. (authors)

  13. Underground facility plan for Horonobe Underground Research Laboratory project

    The basic and most important conditions in forming plans for designing and constructing an underground research facility are ensuring the safety of the facility construction and securing an environment conductive to research. The site presently designated for construction an underground research facility is in a sedimentary soft rock (mudstone) of Neogene period, found to contain methane gas. Evaluating measures to deal with the geological characteristics, including assessment of the stability of support and handling of methane gas, is important in guaranteeing the safety of construction and operation of the research facility once completed. (author)

  14. Full-scale fire experiments on vertical horizontal cable trays

    Two full-scale fire experiments on PVC cables used in nuclear power plants were carried out, one with cables in vertical position and one with cables in horizontal position. The vertical cable bundle, 3 m high, 300 mm wide and 30 mm thick, was attached to a steel cable ladder. The vertical bundle experiment was carried out in nearly free space with three walls near the cable ladder guiding air flow in order to stabilise flames. The horizontal cable experiment was carried out in a small room with five cable bundles attached to steel cable ladders. Three of the 2 m long cable bundles were located in an array, equally spaced above each other near one long side of the room and two correspondingly near the opposite long side. The vertical cable bundle was ignited with a small propane gas burner beneath the lower edge of the bundle. The horizontal cable bundles were ignited with a small propane burner beneath the lowest bundle in an array of three bundles. Rate of heat release by means of oxygen consumption calorimetry, mass change, CO2, CO and smoke production rate and gas, wall and cable surface temperatures were measured as a function of time, as well as time to sprinkler operation and failure of test voltage in cables. Additionally, the minimum rate of heat release needed to ignite the bundle was determined. This paper concentrates on describing and recording the experimental set-up and the data obtained. (orig.)

  15. AcEST: DK950971 [AcEST

    Full Text Available optera acutorost... 37 0.66 tr|B1ACS6|B1ACS6_BALBN DMP1 (Fragment) OS=Balaenoptera ...bonaerens... 37 0.66 tr|B1ACS5|B1ACS5_BALED DMP1 (Fragment) OS=Balaenoptera edeni... GN=... 37 0.66 tr|B1ACS4|B1ACS4_BALBO DMP1 (Fragment) OS=Balaenoptera borealis ... 37 0.66 tr|B1ACS3|B1ACS3..._BALMU DMP1 (Fragment) OS=Balaenoptera musculus ... 37 0.86 tr|B1ACS1|B1ACS1_MEGNO DMP1 (Fragment) OS=Megapt...1ACS2_BALPH DMP1 (Fragment) OS=Balaenoptera physalus ... 37 1.1 tr|B1ACT6|B1ACT6_MESPE DMP1 (Fragment) OS=Me

  16. Cable support for electric poles. Support de cables pour poteau electrique

    Bourrieres, P.

    1989-11-21

    The cable support according to this invention comprises a central body of insulating material upon which are mounted individual cable supports and means for connecting the central body to a pole. In this manner, a support designed to support a plurality of cables is realized in a single operation. On the other hand, the placing of the cable support is carried out by a single operation of connecting the central body to the pole, allowing provision for mounting a cable support after erecting the pole, or in additions, a quick repair by transferring the central body from the broken end fo a pole to a new pole or to the trunk of the pole for a temporary restoration of electrical service.

  17. HTS cables open the window for large-scale renewables

    Geschiere, A.; Willén, D.; Piga, E.; Barendregt, P.

    2008-02-01

    In a realistic approach to future energy consumption, the effects of sustainable power sources and the effects of growing welfare with increased use of electricity need to be considered. These factors lead to an increased transfer of electric energy over the networks. A dominant part of the energy need will come from expanded large-scale renewable sources. To use them efficiently over Europe, large energy transits between different countries are required. Bottlenecks in the existing infrastructure will be avoided by strengthening the network. For environmental reasons more infrastructure will be built underground. Nuon is studying the HTS technology as a component to solve these challenges. This technology offers a tremendously large power transport capacity as well as the possibility to reduce short circuit currents, making integration of renewables easier. Furthermore, power transport will be possible at lower voltage levels, giving the opportunity to upgrade the existing network while re-using it. This will result in large cost savings while reaching the future energy challenges. In a 6 km backbone structure in Amsterdam Nuon wants to install a 50 kV HTS Triax cable for a significant increase of the transport capacity, while developing its capabilities. Nevertheless several barriers have to be overcome.

  18. Evaluation of cable ageing in Nuclear Power Plants; Evaluacion del envejecimiento de cables en centrales nucleares

    Lopez Vergara, T. [Empresarios Agrupados, A. I. E. Madrid (Spain); Alonso Chicote, J. [TECNATOM, S. A. (Spain); Burnay, S. [AEA Technology (UK)

    2000-07-01

    The majority of power, control and instrumentation cables in nuclear power plants use polymers as their basic material for insulation and jacket. In many cases, these cables form part of safety-related circuits and should therefore be capable of operating correctly under both normal and accident conditions. Since polymeric materials are degraded by the long term action of the radiation and thermal environments found in the plant, it is important to be able to establish the cable condition during the plant lifetime. Nowadays there are a number of different methods to evaluate the remaining lifetime of cables. In the case of new plants, or new cables in old plants, accelerated ageing tests and predictive models can be used to establish the behaviour of the cable materials under operating conditions. There are verified techniques and considerable experience in the definition of predictive models. This type of approach is best carried out during the commissioning stage or in the early stages of operation. In older plants, particularly where there is a wide range of cable types in use, it is more appropriate to use condition monitoring methods to establish the state of degradation of cables in-plant. Over the last 10 years there have been considerable developments in methods for condition monitoring of cables and a tool-box of practical techniques are now available. There is no single technique which is suitable for all cable materials but the range of methods covers nearly all of the types currently in use, at present, the most established methods are the indented, thermal analysis (OIT, OITP and TGA) and dielectric loss measurements, All of these are either non-destructive methods or require only micro-samples of material. (Author) 15 refs.

  19. Nonlinear Dielectric Response of Water Treed XLPE Cable Insulation

    Hvidsten, Sverre

    1999-07-01

    Condition assessment of XLPE power cables is becoming increasingly important for the utilities, due to a large number of old cables in service with high probability of failure caused by water tree degradation. The commercial available techniques are generally based upon measurements of the dielectric response, either by time (polarisation/depolarisation current or return voltage) or frequency domain measurements. Recently it has been found that a high number of water trees in XLPE insulated cables causes the dielectric response to increase more than linearly with increasing test voltage. This nonlinear feature of water tree degraded XLPE insulation has been suggested to be of a great importance, both for diagnostic purposes, and for fundamental understanding of the water tree phenomenon itself. The main purpose of this thesis have been to study the nonlinear feature of the dielectric response measured on watertreed XLPE insulation. This has been performed by dielectric response measurements in both time and frequency domain, numerical calculations of losses of simplified water tree models, and fmally water content and water permeation measurements on single water trees. The dielectric response measurements were performed on service aged cable samples and laboratory aged Rogowski type objects. The main reason for performing laboratory ageing was to facilitate diagnostic testing as a function of ageing time of samples containing mainly vented water trees. A new method, based upon inserting NaC1 particles at the interface between the upper semiconductive screen and the insulation, was found to successfully enhance initiation and growth of vented water trees. AC breakdown strength testing show that it is the vented water trees that reduce the breakdown level of both the laboratory aged test objects and service aged cable samples. Vented water treeing was found to cause the dielectric response to become nonlinear at a relatively low voltage level. However, the measured

  20. High voltage pulsed cable design: a practical example

    The design of optimum high voltage pulse cable is difficult because very little emperical data are available on performance in pulsed applications. This paper follows the design and testing of one high voltage pulse cable, 40/100 trigger cable. The design was based on an unproven theory and the impressive outcome lends support to the theory. The theory is outlined and it is shown that there exists an inductance which gives a cable of minimum size for a given maximum stress. Test results on cable manufactured according to the design are presented and compared with the test results on the cable that 40/100 replaces

  1. CSNS control cable information management system based on web

    This paper presents an approach to data modeling a great number of control devices and cables with complicated relations of CSNS (China Spallation Neutron Source). The CSNS accelerator control cable database was created using MySQL, and the control cable information management system based on Web was further built. During the development of the database, the design idea of IRMIS database was studied. and the actual situation of CSNS accelerator control cables was investigated. The control cable database model fitting the requirements was designed. This system is of great convenience to manage and maintain CSNS control devices and cables in the future. (authors)

  2. Cable condition monitoring research activities at Sandia National Laboratories

    Sandia National Laboratories is currently conducting long-term aging research on representative samples of nuclear power plant cables. The objectives of this program are to determine the suitability of these cables for extended life (beyond 40 year design basis) and to assess various cable condition monitoring techniques for predicting remaining cable life. The cables are being aged for long times at relatively mild exposure conditions with various condition monitoring techniques to be employed during the aging process. Following the aging process, the cables will be exposed to a sequential accident profile consisting of high dose rate irradiation followed by a simulated design basis loss-of-coolant accident (LOCA) steam exposure

  3. Energy losses of superconducting power transmission cables in the grid

    Østergaard, Jacob; Okholm, Jan; Lomholt, Karin;

    2001-01-01

    One of the obvious motives for development of superconducting power transmission cables is reduction of transmission losses. Loss components in superconducting cables as well as in conventional cables have been examined. These losses are used for calculating the total energy losses of conventional...... as well as superconducting cables when they are placed in the electric power transmission network. It is concluded that high load connections are necessary to obtain energy saving by the use of HTSC cables. For selected high load connections, an energy saving of 40% is expected. It is shown that the...... thermal insulation and cooling machine efficiency are the most important loss element in a superconducting cable system...

  4. NEPO cable system aging management programs

    Full text: Cable polymer aging and condition monitoring is being studied in detail under the Nuclear Energy Plant Optimization Program (NEPO) that is co-sponsored by the U.S. Department of Energy and EPRI. Significant advances in modeling of polymer aging and condition monitoring have occurred and continue to be developed. The activities include: Analysis of the linearity of the Arrhenius model to room temperature; Development of a wear-out technique for determining remaining life of cable polymers; Determination of the aging fragility point for composite EPR/CSPE insulation with respect to LOCA function; Development of visual/tactile training aids for cable assessment; Development of a totally new nuclear magnetic resonance condition monitoring technique; Assessment of existing techniques with regard to repeatability, accuracy and ease of use. Through use of highly precise oxygen consumption experiments, the linearity of the Arrhenius model is being evaluated. In these experiments, polymer is placed in vials with a known amount of oxygen and aged at much lower temperatures than is possible with standard accelerated aging techniques. aging results are possible at room temperature. The technique is being applied to commonly used insulation and jacket polymers. The wear-out technique allows highly non-linear aging behavior to be made linear. The wearout point of a polymer is determined through high-rate aging and use of a condition monitoring technique to establish the end point. Then, micro-samples of cable that have been naturally aged are subjected to high rate aging to the same end point. The ratio of the remaining high rate aging period to the total high rate aging time provides a linear indication of the remaining service time. Initial screening of nuclear plant cable systems can use visual/tactile techniques to identify cable that has aged significantly. Training aids have been developed by developing sets of specimens with accelerated aging ranging from none

  5. Storage of high-level wastes, investigations in underground laboratories

    This article reviews the different collaborations made by ANDRA (national agency for the management of radioactive wastes) in the fields of underground radioactive waste storage. ANDRA has taken part in various experimental research programs performed in laboratories such as Mol in Belgium, Aspo in Sweden, Pinawa in Canada and Grimsel in Switzerland. This article details the experiments led at Mol since 1984. ANDRA is commissioned by the 30.12.91 decree to study the possibility of storage in deep geological layers. A thorough knowledge of the matter requires the building of underground laboratories in order to test and validate technological choices on a real scale. 6 themes will have to be investigated: 1) the capacity to seal up the storage facility after its use in order to assure the protection of man and environment, 2) the effects of geological perturbations on the confining properties of the site, 3) the confining ability of the Callovian-Oxfordian geological formation, 4) the transfer of radionuclides from the geological formation to the biosphere, 5) the constructing possibility of an underground storage facility, and 6) the possibility of retrieving the stored packages. (A.C.)

  6. Dynamic Underground Stripping Demonstration Project

    LLNL is collaborating with the UC Berkeley College of Engineering to develop and demonstrate a system of thermal remediation and underground imaging techniques for use in rapid cleanup of localized underground spills. Called ''Dynamic Stripping'' to reflect the rapid and controllable nature of the process, it will combine steam injection, direct electrical heating, and tomographic geophysical imaging in a cleanup of the LLNL gasoline spill. In the first 8 months of the project, a Clean Site engineering test was conducted to prove the field application of the techniques before moving to the contaminated site in FY 92

  7. HTS twisted stacked-tape cable conductor

    The feasibility of high field magnet applications of the twisted stacked-tape cabling method with 2G YBCO tapes has been investigated. An analysis of torsional twist strains of a thin HTS tape has been carried out taking into account the internal shortening compressive strains accompanied with the lengthening tensile strains due to the torsional twist. The model is benchmarked against experimental tests using YBCO tapes. The critical current degradation and current distribution of a four-tape conductor was evaluated by taking account of the twist strain, the self-field and the termination resistances. The critical current degradation for the tested YBCO cables can be explained by the perpendicular self-field effect. It is shown that the critical current of a twisted stacked-tape conductor with a four-tape cable does not degrade with a twist pitch length as short as 120 mm. Current distribution among tapes and hysteresis losses are also investigated. A compact joint termination method for a 2G YBCO tape cable has been developed. The twisted stacked-tape conductor method may be an attractive means for the fabrication of highly compact, high current cables from multiple flat HTS tapes.

  8. AC1 Wing

    Adrian DOBRE

    2010-03-01

    Full Text Available The AC1 wing replaces the old wing of the wind tunnel model AEROTAXI, which has been made at scale 1:9. The new wing is part of CESAR program and improves the aerodynamic characteristics of the old one. The geometry of the whole wing was given by FOI Sweden and position of AC1 wing must coincide with the structure of the AEROTAXI model.

  9. AC1 Wing

    Adrian DOBRE

    2010-01-01

    The AC1 wing replaces the old wing of the wind tunnel model AEROTAXI, which has been made at scale 1:9. The new wing is part of CESAR program and improves the aerodynamic characteristics of the old one. The geometry of the whole wing was given by FOI Sweden and position of AC1 wing must coincide with the structure of the AEROTAXI model.

  10. Computer-Aided Engineering Of Cabling

    Billitti, Joseph W.

    1989-01-01

    Program generates data sheets, drawings, and other information on electrical connections. DFACS program, centered around single data base, has built-in menus providing easy input of, and access to, data for all personnel involved in system, subsystem, and cabling. Enables parallel design of circuit-data sheets and drawings of harnesses. Also recombines raw information to generate automatically various project documents and drawings, including index of circuit-data sheets, list of electrical-interface circuits, lists of assemblies and equipment, cabling trees, and drawings of cabling electrical interfaces and harnesses. Purpose of program to provide engineering community with centralized data base for putting in, and gaining access to, functional definition of system as specified in terms of details of pin connections of end circuits of subsystems and instruments and data on harnessing. Primary objective to provide instantaneous single point of interchange of information, thus avoiding

  11. Distance and Cable Length Measurement System

    Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay

    2009-01-01

    A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169

  12. Insulation systems for superconducting transmission cables

    Tønnesen, Ole

    This paper describes shortly the status of superconducting transmission lines and assesses what impact the recently discovered BSCCO superconductors may have on the design of the cables.Two basically different insulation systems are discussed:1) The room temperature dielectric design, where the...... electrical insulation is placed outside both the superconducting tube and the cryostat. The superconducting tube is cooled by liquid nitrogen which is pumped through the hollow part of the tube.2) The cryogenic dielectric design, where the electrical insulation is placed inside the cryostat and thus is kept...... at temperature near 77 K.The optimal design is determined by a loss evaluation in relation to the power transfer capacity of the cable. Development work in progress on the design and construction of superconducting cables in Denmark is described as an example....

  13. Aging assessment of nuclear generating station cables

    A number of diagnostic techniques requiring small samples (e.g. shavings) for monitoring the condition of nuclear generating station cables have been identified. The cables studied were insulated with cross-linked or unmodified polyethylene, ethylene propylene rubber, butyl rubber, styrene butadiene rubber, and polyvinyl chloride. Specimens were aged at elevated temperatures, or gamma irradiated up to 120 Mrad. The degradation was assessed by conventional elongation measurements, differential scanning calorimetry (DSC), oxidation induction time, DSC oxidation induction temperature (under high oxygen pressure), infrared carbonyl absorption, density, and swelling measurements. The sensitivities of the diagnostic techniques in measuring oxidation and embrittlement were compared with the elongation results, and a criterion for monitoring the cable degradation was developed. Some results presented illustrate the use of the diagnostic techniques in monitoring degradation. 13 refs., 2 tabs., 24 figs

  14. Electrothermal Coordination in Cable Based Transmission Grids

    Olsen, Rasmus Schmidt; Holbøll, Joachim; Gudmundsdottir, Unnur Stella

    2013-01-01

    Electrothermal coordination (ETC) is introduced for cable based transmission grids. ETC is the term covering operation and planning of transmission systems based on temperature, instead of current. ETC consists of one part covering the load conditions of the system and one covering the thermal...... behavior of the components. The dynamic temperature calculations of power cables are suggested to be based on thermoelectric equivalents (TEEs). It is shown that the thermal behavior can be built into widely used load flow software, creating a strong ETC tool. ETC is, through two case scenarios, proven to...... be beneficial for both operator and system planner. It is shown how the thermal behavior can be monitored in real-time during normal dynamic load and during emergencies. In that way, ETC enables cables to be loaded above their normal rating, while maintaining high reliability of the system, which...

  15. Trackless centre pivot-steered underground vehicle with electric-motor drive. Gleisloses knickgelenktes Untertagefahrzeug mit Elektromotorantrieb

    Hillmann, W.; Paus, H.; Drews, E.

    1989-05-03

    Trackless, centre pivot-steered underground vehicle with electric-motor drive of the tractor section, the supply of energy to which takes place via sliding contact line and a current-collecting device which can be driven thereon, and via a connecting cable which is connected electrically and mechanically to the latter and can be unwound from a reel against a restoring force, characterised by the combination of the following features: (a) the connecting cable (supply cable) is connected to the current-collecting device via a slip-ring member which can be rotated about a vertical axle; (b) a cable reel which winds in a spiral and is driven by a hydraulic motor is mounted on the tractor section so as to be rotatable about a vertical axle, the axle being equipped with a slip-ring member; (c) a hydraulically pivotable guide arm is arranged coaxially to the cable reel; (d) a hydrostatic axial piston transmission for the travelling mechanism and drive in (b) and (c) is coupled to a three phase current motor. 1 fig.

  16. Fiberglass underground petroleum storage systems

    Fiberglass Reinforced Plastic (FRP) products have been in use for many years in a wide variety of products and markets. The automotive, marine, military, chemical, and petroleum markets have made extensive use of FRP. Today, over 300,000 FRP tanks and over 40,000,000 feet of FRP pipe are in service in petroleum marketing as well as industrial and commercial storage applications. In the early 1960's the American Petroleum Institute invited the FRP industry to design FRP underground tanks to solve their corrosion caused underground leaker problems. The challenge was accepted and in 1965 FRP tanks were introduced to the petroleum storage marketplace. FRP pipe, specifically designed for underground petroleum use, was Underwriter's Laboratories tested and listed and introduced in 1968. These fiberglass tanks and pipe have a 25 year perfect record against both internal and external corrosion. The FRP tank and pipe performance record has been outstanding. Less than 1/2 of 1% have ever been involved in an in-ground failure. When first introduced, FRP tanks carried an initial cost premium of 50 to 100% over unprotected steel. Since all Underground Storage Tank (UST) systems must be corrosion protected, initial FRP costs are now competitive with corrosion protected steel

  17. Underground nuclear explosions and earthquakes

    The stages that have marked the ways towards the interdiction of nuclear tests are reviewed. Although seismographic equipments have been greatly improved, it is shown that a separate detection of underground nuclear explosions from natural seismic vibrations is still quite uneasy. The use of nuclear loads for civil engineering still makes it more complicate to apply a treatee of interdiction of nuclear tests

  18. 30 CFR 72.630 - Drill dust control at underground areas of underground mines.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drill dust control at underground areas of underground mines. 72.630 Section 72.630 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT... dust control at underground areas of underground mines. (a) Dust resulting from drilling in rock...

  19. Calorimetric measurements of losses in HTS cables

    Tønnesen, Ole; Veje, Niels Erling Winsløv; Rasmussen, Carsten;

    2001-01-01

    A calorimetric test rig is used to investigate various loss components in a 10 m long superconducting cable model. A calorimetric technique, based on thermocouple measurements, is used to measure the losses of the 10 m long superconducting cable model. The current dependent losses are also measured...... electrically and compared with the losses obtained with the calorimetric method. The results obtained by the two methods are consistent. Based on an I2 (current) fitting procedure, the loss, caused by the eddy current generated in the stainless steel cryostat housing, and the hysteresis loss generated in the...

  20. Configuration Synthesis for Fully Restrained 7-Cable-Driven Manipulators

    Xiaoqiang Tang

    2012-10-01

    Full Text Available Cable distribution plays a vital role in Cable Driven Parallel Manipulators (CDPMs regarding tension and workspace quality, especially in fully restrained CDPMs. This paper focuses on three typical configurations of fully restrained CDPMs with 7 cables in order to introduce an approach for configuration synthesis. Firstly, the kinematic models of three types of CDPMs with 7 cables are set up. Then, in order to evaluate workspace quality, two new indices are proposed by using tensions along each cable, which are the All Cable Tension Distribution Index (ACTDI and Global Tension Distribution Index (GTDI. Next, the three types of CDPMs with 7 cables are analysed with the two indices. At the end, according to different performance requirements, the configurations of cable distribution are discussed and selected.

  1. Superscreened co-axial cables for the nuclear power industry

    This specification covers the requirements of superscreened cables. Part 1 covers general requirements and test methods. Part 2 covers data sheets setting out the electrical and mechanical requirements for each type of cable, together with engineering information. (U.K.)

  2. Fault Management of a Cold Dielectric HTS Power Transmission Cable

    High temperature superconductor (HTS) power transmission cables offer significant advantages in power density over conventional copper-based cables. As with conventional cables, HTS cables must be safe and reliable when abnormal conditions, such as local and through faults, occur in the power grid. Due to the unique characteristics of HTS power cables, the fault management of an HTS cable is different from that of a conventional cable. Issues, such as nitrogen bubble formation within lapped dielectric material, need to be addressed. This paper reviews the efforts that have been performed to study the fault conditions of a cold dielectric HTS power cable. As a result of the efforts, a fault management scheme has been developed, which provides both local and through faults system protection. Details of the fault management scheme with examples are presented

  3. Dynamic Analysis of Towed and Variable Length Cable Systems

    WANG Shu-xin; WANG Yan-hui; LI Xiao-ping

    2007-01-01

    Towed cable systems are frequently used in marine measurements where the length of the towed cable varies during launch and recovery. In this paper a novel method for modeling variable length cable systems is introduced based on the finite segment formulation. The variable length of the towed cable is described by changing the length of the segment near the towing point and by increasing or decreasing the number of the discrete segments of the cable. In this way, the elastic effects of the cable can be easily handled since geometry and material properties of each segment are kept constant. Experimental results show that the dynamic behavior of the towed cable is consistent between the model and the physical cable. Results show that the model provides numerical efficiency and simulation accuracy for the variable length towed system.

  4. Basic Requirements for Cables of Systems Important to NPP Safety

    In view of the need for equipment upgrades at Ukrainian nuclear power plants, the replacement of cables, as an integral part of any system, becomes important. There is no document in Ukraine that combines requirements for cables of systems important to nuclear safety. The paper systematizes the technical requirements of national regulatory documents on nuclear and radiation safety in relation to cable products. The most important requirements for selecting cables are fire safety, resistance to high temperatures, humidity and pressure, resistance to ionizing radiation, seismic resistance and electromagnetic compatibility. The use of cables in the NPP containment and safety systems imposes on them the most stringent requirements as regards nuclear and radiation safety in plant operation. The paper identifies features and operating conditions for cable lines as part of NPP safety systems and shows the general classification of cable products. Development of a regulatory document to combine requirements for cables of safety systems will facilitate their selection during upgrading.

  5. Analysis of Electrical Coupling Parameters in Superconducting Cables

    Bottura, L; Rosso, C

    2003-01-01

    The analysis of current distribution and redistribution in superconducting cables requires the knowledge of the electric coupling among strands, and in particular the interstrand resistance and inductance values. In practice both parameters can have wide variations in cables commonly used such as Rutherford cables for accelerators or Cable-in-Conduits for fusion and SMES magnets. In this paper we describe a model of a multi-stage twisted cable with arbitrary geometry that can be used to study the range of interstrand resistances and inductances that is associated with variations of geometry. These variations can be due to cabling or compaction effects. To describe the variations from the nominal geometry we have adopted a cable model that resembles to the physical process of cabling and compaction. The inductance calculation part of the model is validated by comparison to semi-analytical results, showing excellent accuracy and execution speed.

  6. Nonlinear dynamic response of stay cables under axial harmonic excitation

    Xu XIE; He ZHAN; Zhi-cheng ZHANG

    2008-01-01

    This paper proposes a new numerical simulation method for analyzing the parametric vibration of stay cables based on the theory of nonlinear dynamic response of structures under the asynchronous support excitation.The effects of important parameters related to parametric vibration of cables,I.e., characteristics of structure,excitation frequency,excitation amplitude,damping effect of the air and the viscous damping coefficient of the cables,were investigated by using the proposed method for the cables with significant length difference as examples.The analysis results show that nonlinear finite element method is a powerful technique in analyzing the parametric vibration of cables,the behavior of parametric vibration of the two cables with different Irvine parameters has similar properties,the amplitudes of parametric vibration of cables are related to the frequency and amplitude of harmonic support excitations and the effect of distributed viscous damping on parametric vibration of the cables is very small.

  7. Urban underground resources management for sustainable development

    Li, Huanqing

    2010-01-01

    Urban problems such as congestions, land scarcity, pollutions, could be alleviated by underground solutions, which are critical underground infrastructues and buildings adaptable to subsurface. An integrated approach of urban underground management is put forward, aiming to research on the feasability of developing valuable subsurface, and to promote the sustainability of resources' multi-usage exploitation.

  8. 49 CFR 192.325 - Underground clearance.

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Underground clearance. 192.325 Section 192.325... Lines and Mains § 192.325 Underground clearance. (a) Each transmission line must be installed with at least 12 inches (305 millimeters) of clearance from any other underground structure not associated...

  9. Deep underground intensities of high energy muons

    The experiment of the deep underground emulsion chamber has been started in order to measure the energy spectra of muons deep underground at high energies. Preliminary results based on the emulsion chamber with 0.9 ton of lead are presented. This test exposure has been performed at the vertical depth of 850 hg/cm2 underground in the road tunnel. (orig.)

  10. Composite Based EHV AC Overhead Transmission Lines

    Sørensen, Thomas Kjærsgaard

    Overhead lines at transmission level are the backbone of any national power grid today. New overhead line projects however are at the same time subject to ever greater public resistance due to the lines environmental impact. As full undergrounding of transmission lines at extra high voltage (EHV......) levels are still not seen as possibility, the future expansion of transmission grids are dependent on new solutions with lessened environment impact, especially with regard to the visual impact. In the present Thesis, composite materials and composite based overhead line components are presented and...... analysed with regard to the possibilities, limitations and risks widespread application of composite materials on EHV AC overhead transmission lines may present. To form the basis for evaluation of the useability of composite materials, dierent overhead line projects aimed at reducing the environmental...

  11. Broadcast Service Areas, Cable, cable, Published in Not Provided, 1:600 (1in=50ft) scale, Comcast.

    NSGIC GIS Inventory (aka Ramona) — This Broadcast Service Areas, Cable dataset, published at 1:600 (1in=50ft) scale as of Not Provided. It is described as 'cable'. Data by this publisher are often...

  12. Environmental Impact of a Submarine Cable: Case Study of the Acoustic Thermometry of Ocean Climate (ATOC)/ Pioneer Seamount Cable

    Kogan, I.; Paull, C. K.; Kuhnz, L.; von Thun, S.; Burton, E.; Greene, H. G.; Barry, J. P.

    2003-12-01

    To better understand the potential impacts of the presence of cables on the seabed, a topic of interest for which little data is published or publicly available, a study of the environmental impacts of the ATOC/Pioneer Seamount cable was conducted. The 95 km long, submarine, coaxial cable extends between Pioneer Seamount and the Pillar Point Air Force Station in Half Moon Bay, California. Approximately two thirds of the cable lies within the Monterey Bay National Marine Sanctuary. The cable is permitted to NOAA- Oceanic and Atmospheric Research for transmitting data from a hydrophone array on Pioneer Seamount to shore. The cable was installed unburied on the seafloor in 1995. The cable path crosses the continental shelf, descends to a maximum depth of 1,933 m, and climbs back upslope to 998 m depth near the crest of Pioneer Seamount. A total of 42 hours of video and 152 push cores were collected in 10 stations along cable and control transects using the ROVs Ventana and Tiburon equipped with cable-tracking tools. The condition of the cable, its effect on the seafloor, and distribution of benthic megafauna and infauna were determined. Video data indicated the nature of interaction between the cable and the seafloor. Rocky nearshore areas, where wave energies are greatest, showed the clearest evidence of impact. Here, evidence of abrasion included frayed and unraveling portions of the cable's armor and vertical grooves in the rock apparently cut by the cable. The greatest incision and armor damage occurred on ledges between spans in irregular rock outcrop areas. Unlike the nearshore rocky region, neither the rocks nor the cable appeared damaged along outcrops on Pioneer Seamount. Multiple loops of slack cable added during a 1997 cable repair operation were found lying flat on the seafloor. Several sharp kinks in the cable were seen at 240 m water depths in an area subjected to intense trawling activity. Most of the cable has become buried with time in sediment

  13. 47 CFR 76.111 - Cable sports blackout.

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Cable sports blackout. 76.111 Section 76.111... CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.111 Cable sports blackout. (a) No community unit located in whole or in part within the...

  14. Working Paper for the Revision of San Francisco's Cable Franchise.

    San Francisco Public Library, CA. Video Task Force.

    Ideas are presented for the revision of San Francisco's cable franchise. The recommendations in the report are based upon national research of library and urban use of cable communications and are designed to help the city's present and future cable franchises to comply with the regulations of the Federal Communications Commission by March 31,…

  15. Estimation of Medium Voltage Cable Parameters for PD Detection

    Villefrance, Rasmus; Holbøll, Joachim T.; Henriksen, Mogens

    measured signal at the cable terminations to a specific PD-amplitude and location on the cable, the attenuation and the transmission speed of PD-pulses on the cable have to be known. Consequently, the main parameter to be determined is the complex propagation constant which consists of the attenuation and...

  16. 47 CFR 32.2426 - Intrabuilding network cable.

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Intrabuilding network cable. 32.2426 Section 32... Intrabuilding network cable. (a) This account shall include the original cost of cables and wires located on the company's side of the demarcation point or standard network interface inside subscribers' buildings...

  17. 47 CFR 32.6426 - Intrabuilding network cable expense.

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Intrabuilding network cable expense. 32.6426... Intrabuilding network cable expense. (a) This account shall include expenses associated with intrabuilding network cable. (b) Subsidiary record categories shall be maintained as provided in § 32.2426(a) of...

  18. Ground Return Current Behaviour in High Voltage Alternating Current Insulated Cables

    Roberto Benato

    2014-12-01

    Full Text Available The knowledge of ground return current in fault occurrence plays a key role in the dimensioning of the earthing grid of substations and of cable sealing end compounds, in the computation of rise of earth potential at substation sites and in electromagnetic interference (EMI on neighbouring parallel metallic conductors (pipes, handrails, etc.. Moreover, the ground return current evaluation is also important in steady-state regime since this stray current can be responsible for EMI and also for alternating current (AC corrosion. In fault situations and under some assumptions, the ground return current value at a substation site can be computed by means of k-factors. The paper shows that these simplified and approximated approaches have a lot of limitations and only multiconductor analysis can show the ground return current behaviour along the cable (not only the two end values both in steady-state regime and in short circuit occurrence (e.g., phase-to-ground and phase-to-phase-to-ground. Multiconductor cell analysis (MCA considers the cable system in its real asymmetry without simplified and approximated hypotheses. The sensitivity of ground return current on circuit parameters (cross-bonding box resistances, substation earthing resistances, soil resistivity is presented in the paper.

  19. Broadband Wireline Provider Service: Cable Modem - Other; BBRI_cableOther12

    University of Rhode Island Geospatial Extension Program — This dataset represents the availability of wireline broadband Internet access in Rhode Island via "Cable Modem - Other" technology. Broadband availability is...

  20. Broadband Wireline Provider Service: Cable Modem - DOCSIS 3.0; BBRI_cableDOCSIS12

    University of Rhode Island Geospatial Extension Program — This dataset represents the availability of wireline broadband Internet access in Rhode Island via "Cable Modem - DOCSIS 3.0" technology. Broadband availability is...

  1. Overhead lines: materials. Guard conductors and cables; Lignes aeriennes: materiels. Conducteurs et cables de garde

    Chanal, A. [Electricite de France (EDF), 75 - Paris (France). Direction de la Production et du Transport; Leveque, J.P. [Electricite de France (EDF), Reseau de Transport d' Electricite, 75 - Paris (France)

    2003-02-01

    This article presents the characteristics of bare cables for the construction of overhead lines. During the last decades, no important change has been made in the choice of conductive materials. The main materials used are: the high purity cold drawn aluminium in bi-metal aluminium-steel cables, and the 'almelec', an aluminium alloy with a reinforced traction resistance. Recently, new conductors with a higher transport capacity and a better temperature resistance have been developed. Another way of research concerns the combination of conductors and composite materials (carbon fibers) but no satisfactory solutions have been obtained so far. A more important evolution concerns the guard cables for high voltage lines which now include telecommunication circuits (optical fibers) for high flow rate transmission of numerical data. The laying out of such cables has been generalized in France in order to supply the overall territory with equivalent and satisfactory performances. (J.S.)

  2. Cooperative Behaviours with Swarm Intelligence in Multirobot Systems for Safety Inspections in Underground Terrains

    Chika Yinka-Banjo

    2014-01-01

    Full Text Available Underground mining operations are carried out in hazardous environments. To prevent disasters from occurring, as often as they do in underground mines, and to prevent safety routine checkers from disasters during safety inspection checks, multirobots are suggested to do the job of safety inspection rather than human beings and single robots. Multirobots are preferred because the inspection task will be done in the minimum amount of time. This paper proposes a cooperative behaviour for a multirobot system (MRS to achieve a preentry safety inspection in underground terrains. A hybrid QLACS swarm intelligent model based on Q-Learning (QL and the Ant Colony System (ACS was proposed to achieve this cooperative behaviour in MRS. The intelligent model was developed by harnessing the strengths of both QL and ACS algorithms. The ACS optimizes the routes used for each robot while the QL algorithm enhances the cooperation between the autonomous robots. A description of a communicating variation within the QLACS model for cooperative behavioural purposes is presented. The performance of the algorithms in terms of without communication, with communication, computation time, path costs, and the number of robots used was evaluated by using a simulation approach. Simulation results show achieved cooperative behaviour between robots.

  3. Insulation system for high temperature superconductor cables

    Michael, P. C.; Haight, A. E.; Bromberg, L.; Kano, K.

    2015-12-01

    Large-scale superconductor applications, like fusion magnets, require high-current capacity conductors to limit system inductance and peak operating voltage. Several cabling methods using high temperature superconductor (HTS) tapes are presently under development so that the unique high-field, high-current-density, high operating temperature characteristics of 2nd generation REBCO coated conductors can be utilized in next generation fusion devices. Large-scale magnets are generally epoxy impregnated to support and distribute electromagnetic stresses through the magnet volume. However, the present generation of REBCO coated conductors are prone to delamination when tensile stresses are applied to the broad surface of REBCO tapes; this can occur during epoxy cure, cooldown, or magnet energization. We present the development of an insulation system which effectively insulates HTS cabled conductors at high withstand voltage while simultaneously preventing the intrusion of the epoxy impregnant into the cable, eliminating degradation due to conductor delamination. We also describe a small-scale coil test program to demonstrate the cable insulation scheme and present preliminary test results.

  4. Modeling of Pressure Effects in HVDC Cables

    Szabo, Peter; Hassager, Ole; Strøbech, Esben

    1999-01-01

    A model is developed for the prediction of pressure effects in HVDC mass impregnatedcables as a result of temperature changes.To test the model assumptions, experiments were performed in cable like geometries.It is concluded that the model may predict the formation of gas cavities....

  5. Dynamic Loadability of Cable Based Transmission Grids

    Olsen, Rasmus Schmidt

    supervised 2 master projects, as well as 5 special courses at DTU. Furthermore I created and taught a cable course, with approximately 25 students, throughout 13 weeks during the spring of 2011. The PhD project has until now contributed with 3 journal papers and 4 conference papers. Selected papers can be...

  6. Dutch VULA consumer market services over Cable

    Anoniem

    2015-01-01

    KPN offers a virtual unbundled local access wholesale service over its DSL infrastructure. This offer has been accepted by the Dutch Authority Consumer Market. In the report, it is argued that for consumer market services, the Dutch cable providers can develop an equivalent wholesale service from th

  7. Study on Impedance Characteristics of Aircraft Cables

    Weilin Li

    2016-01-01

    Full Text Available Voltage decrease and power loss in distribution lines of aircraft electric power system are harmful to the normal operation of electrical equipment and may even threaten the safety of aircraft. This study investigates how the gap distance (the distance between aircraft cables and aircraft skin and voltage frequency (variable frequency power supply will be adopted for next generation aircraft will affect the impedance of aircraft cables. To be more precise, the forming mechanism of cable resistance and inductance is illustrated in detail and their changing trends with frequency and gap distance are analyzed with the help of electromagnetic theoretical analysis. An aircraft cable simulation model is built with Maxwell 2D and the simulation results are consistent with the conclusions drawn from the theoretical analysis. The changing trends of the four core parameters of interest are analyzed: resistance, inductance, reactance, and impedance. The research results can be used as reference for the applications in Variable Speed Variable Frequency (VSVF aircraft electric power system.

  8. History of cable-stayed bridges

    Gimsing, Niels Jørgen

    1999-01-01

    The principle of supporting a bridge deck by inclined tension members leading to towers on either side of the span has been known for centuries. However, the real development of cable-stayed bridges did not begin before the 1950s. Since then the free span has been increased from 183 m in the Strö...

  9. Integration of HTS Cables in the Future Grid of the Netherlands

    Zuijderduin, R.; Chevtchenko, O.; Smit, J. J.; Aanhaanen, G.; Melnik, I.; Geschiere, A.

    Due to increasing power demand, the electricity grid of the Netherlands is changing. The future transmission grid will obtain electrical power generated by decentralized renewable sources, together with large scale generation units located at the coastal region. In this way electrical power has to be distributed and transmitted over longer distances from generation to end user. Potential grid issues like: amount of distributed power, grid stability and electrical loss dissipation merit particular attention. High temperature superconductors (HTS) can play an important role in solving these grid problems. Advantages to integrate HTS components at transmission voltages are numerous: more transmittable power together with less emissions, intrinsic fault current limiting capability, lower ac loss, better control of power flow, reduced footprint, less magnetic field emissions, etc. The main obstacle at present is the relatively high price of HTS conductor. However as the price goes down, initial market penetration of several HTS components (e.g.: cables, fault current limiters) is expected by year 2015. In the full paper we present selected ways to integrate EHV AC HTS cables depending on a particular future grid scenario in the Netherlands.

  10. Possibility of high level waste underground disposal

    The possibility that the high level wastes disposed underground return to the biosphere again is the dissolution and transport of radioactive nuclides by underground water. As the strata suitable to underground disposal, rock salt strata without underground water, and granite or shale strata in which the movement of underground water is slight are enumerated as the candidates. Wastes are formed into solidified bodies like glass, moreover the technical measures such as canisters and overpacks are applied, therefore even if underground water intrudes into the places of disposal, radioactive nuclides can be contained for considerable time. At the time of selecting the most suitable stratum and designing and evaluating the place of disposal to construct the underground disposal system with high potential for high level wastes, it is necessary to predict the movement of radioactive nuclides from the dissolution into underground water to the return to the biosphere. The potential danger of high level wastes, the danger of high level wastes disposed underground, the effect of isolation distance (the thickness of strata), and the comparison of the danger due to uranium ore and slag and the places of underground disposal are explained. The danger due to uranium ore and slag occurs early and lasts long, and is 1000 times as dangerous as the high level wastes disposed underground. (Kako, I.)

  11. Cable deformation simulation and a hierarchical framework for Nb{sub 3}Sn Rutherford cables

    Arbelaez, D; Prestemon, S O; Ferracin, P; Godeke, A; Dietderich, D R; Sabbi, G, E-mail: darbelaez@lbl.go [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2010-06-01

    Knowledge of the three-dimensional strain state induced in the superconducting filaments due to loads on Rutherford cables is essential to analyze the performance of Nb{sub 3}Sn magnets. Due to the large range of length scales involved, we develop a hierarchical computational scheme that includes models at both the cable and strand levels. At the Rutherford cable level, where the strands are treated as a homogeneous medium, a three-dimensional computational model is developed to determine the deformed shape of the cable that can subsequently be used to determine the strain state under specified loading conditions, which may be of thermal, magnetic, and mechanical origins. The results can then be transferred to the model at the strand/macro-filament level for rod restack process (RRP) strands, where the geometric details of the strand are included. This hierarchical scheme can be used to estimate the three-dimensional strain state in the conductor as well as to determine the effective properties of the strands and cables from the properties of individual components. Examples of the modeling results obtained for the orthotropic mechanical properties of the Rutherford cables are presented.

  12. Cable deformation simulation and a hierarchical framework for Nb3Sn Rutherford cables

    Arbelaez, D.; Prestemon, S. O.; Ferracin, P.; Godeke, A.; Dietderich, D. R.; Sabbi, G.

    2009-09-13

    Knowledge of the three-dimensional strain state induced in the superconducting filaments due to loads on Rutherford cables is essential to analyze the performance of Nb{sub 3}Sn magnets. Due to the large range of length scales involved, we develop a hierarchical computational scheme that includes models at both the cable and strand levels. At the Rutherford cable level, where the strands are treated as a homogeneous medium, a three-dimensional computational model is developed to determine the deformed shape of the cable that can subsequently be used to determine the strain state under specified loading conditions, which may be of thermal, magnetic, and mechanical origins. The results can then be transferred to the model at the strand/macro-filament level for rod restack process (RRP) strands, where the geometric details of the strand are included. This hierarchical scheme can be used to estimate the three-dimensional strain state in the conductor as well as to determine the effective properties of the strands and cables from the properties of individual components. Examples of the modeling results obtained for the orthotropic mechanical properties of the Rutherford cables are presented.

  13. A unique cabling designed to produce Rutherford-type superconducting cable for the SSC project

    Up to 25,000 Km of keystoned flat cable must be produced for the SSC project. Starting from a specification developed by Lawrence Berkeley Laboratory (LBL), a special cabling machine has been designed by Dour Metal. It has been designed to be able to run at a speed corresponding to a maximum production rate of 10 m/min. This cabling machine is the key part of the production line which consists of a precision Turkshead equipped with a variable power drive, a caterpillar, a dimensional control bench, a data acquisition system, and a take-up unit. The main features of the cabling unit to be described are a design with nearly equal path length between spool and assembling point for all the wires, and the possibility to run the machine with several over- or under-twisting ratios between cable and wires. These requirements led Dour Metal to the choice of an unconventional mechanical concept for a cabling machine. 4 refs., 2 figs

  14. Distribution of AC loss in a HTS magnet for SMES with different operating conditions

    Xu, Y.; Tang, Y.; Ren, L.; Jiao, F.; Song, M.; Cao, K.; Wang, D.; Wang, L.; Dong, H.

    2013-11-01

    The AC loss induced in superconducting tape may affect the performance of a superconducting device applied to power system, such as transformer, cable, motor and even Superconducting Magnetic Energy Storage (SMES). The operating condition of SMES is changeable due to the need of compensation to the active or reactive power according to the demand of a power grid. In this paper, it is investigated that the distribution of AC loss for a storage magnet on different operating conditions, which is based on finite element method (FEM) and measured properties of BSCCO/Ag tapes. This analytical method can be used to optimize the SMES magnet.

  15. 2nd International Conference on Cable-Driven Parallel Robots

    Bruckmann, Tobias

    2015-01-01

    This volume presents the outcome of the second forum to cable-driven parallel robots, bringing the cable robot community together. It shows the new ideas of the active researchers developing cable-driven robots. The book presents the state of the art, including both summarizing contributions as well as latest research and future options. The book cover all topics which are essential for cable-driven robots: Classification Kinematics, Workspace and Singularity Analysis Statics and Dynamics Cable Modeling Control and Calibration Design Methodology Hardware Development Experimental Evaluation Prototypes, Application Reports and new Application concepts

  16. Underground spaces/cybernetic spaces

    Tomaž Novljan

    2000-01-01

    Full Text Available A modern city space is a space where in the vertical and horizontal direction dynamic, non-linear processes exist, similar as in nature. Alongside the “common” city surface, cities have underground spaces as well that are increasingly affecting the functioning of the former. It is the space of material and cybernetic communication/transport. The psychophysical specifics of using underground places have an important role in their conceptualisation. The most evident facts being their limited volume and often limited connections to the surface and increased level of potential dangers of all kinds. An efficient mode for alleviating the effects of these specific features are artistic interventions, such as: shape, colour, lighting, all applications of the basic principles of fractal theory.

  17. ac bidirectional motor controller

    Schreiner, K.

    1988-01-01

    Test data are presented and the design of a high-efficiency motor/generator controller at NASA-Lewis for use with the Space Station power system testbed is described. The bidirectional motor driver is a 20 kHz to variable frequency three-phase ac converter that operates from the high-frequency ac bus being designed for the Space Station. A zero-voltage-switching pulse-density-modulation technique is used in the converter to shape the low-frequency output waveform.

  18. Underground leaching of uranium ores

    Large amounts of low-grade U ore, not worth processing by conventional methods, are to be found at many sites in mine pillars, walls, and backfilling. Many proven deposits are not being mined because the geological conditions are difficult or the U ore is of relatively low grade. Factors such as radioactive emission, radon emanation, and the formation of radioactive dust give rise to health hazards. When U ores are treated above ground, enormous quantities of solid and liquid radioactive waste and mining spoil accumulate. The underground leaching of U is a fundamentally different kind of process. It is based on the selective dissolving of U at the place where it occurs by a chemical reagent; all that reaches the ground surface is a solution containing U, and after extraction of the U by sorption the reagent is used again. The main difficult and dangerous operations associated with conventional methods (excavation; extraction and crushing of the ore; storage of wastes) are avoided. Before underground leaching the ore formation has to be fractured and large ore bodies broken down into blocks by shrinkage stopping. These operations are carried out by advanced machinery and require the presence underground of only a few workers. If the ore is in seams, the only mining operation is the drilling of boreholes. The chemical reagent is introduced under pressure through one set of boreholes, while the U bearing solution is pumped out from another set. The process is monitored with the help of control boreholes. After extraction of the U by sorption, the reagent is ready to be used again. Very few operations are involved and insignificant amounts of dissolved U escape into the surrounding rock formations. Experience has shown that underground leaching reduces the final cost of the U metal, increases productivity, reduces capital expenditure, and radically improves working conditions

  19. Double wall underground storage tank

    Canaan, E.B. Jr.; Wiegand, J.R.; Bartlow, D.H.

    1993-07-06

    A double wall underground storage tank is described comprising: (a) a cylindrical inner wall, (b) a cylindrical outer wall comprising plastic resin and reinforcement fibers, and (c) a layer of spacer filaments wound around the inner wall, the spacer filaments separating the inner and outer walls, and the spacer filaments being at least partially surrounded by voids to enable liquids to flow along the filaments.

  20. Underground storage of carbon dioxide

    Tanaka, Shoichi [Univ. of Tokyo, Hongo, Bunkyo-ku (Japan)

    1993-12-31

    Desk studies on underground storage of CO{sub 2} were carried out from 1990 to 1991 fiscal years by two organizations under contract with New Energy and Indestrial Technology Development Organization (NEDO). One group put emphasis on application of CO{sub 2} EOR (enhanced oil recovery), and the other covered various aspects of underground storage system. CO{sub 2} EOR is a popular EOR method in U.S. and some oil countries. At present, CO{sub 2} is supplied from natural CO{sub 2} reservoirs. Possible use of CO{sub 2} derived from fixed sources of industries is a main target of the study in order to increase oil recovery and storage CO{sub 2} under ground. The feasibility study of the total system estimates capacity of storage of CO{sub 2} as around 60 Gton CO{sub 2}, if worldwide application are realized. There exist huge volumes of underground aquifers which are not utilized usually because of high salinity. The deep aquifers can contain large amount of CO{sub 2} in form of compressed state, liquefied state or solution to aquifer. A preliminary technical and economical survey on the system suggests favorable results of 320 Gton CO{sub 2} potential. Technical problems are discussed through these studies, and economical aspects are also evaluated.

  1. The stress and underground environment

    Chama, A.

    2009-04-01

    Currently,the program of prevention in occupational health needs mainly to identify occupational hazards and strategy of their prevention.Among these risks,the stress represents an important psycho-social hazard in mental health,which unfortunately does not spare no occupation.My Paper attempts to highlight and to develop this hazard in its different aspects even its regulatory side in underground environment as occupational environment.In the interest of better prevention ,we consider "the information" about the impact of stress as the second prevention efficient and no expensive to speleologists,hygienists and workers in the underground areas. In this occasion of this event in Vienna,we also highlight the scientific works on the stress of the famous viennese physician and endocrinologist Doctor Hans Selye (1907-1982),nicknamed "the father of stress" and note on relation between biological rhythms in this underground area and psychological troubles (temporal isolation) (Jurgen Aschoff’s works and experiences out-of time).

  2. First ATLAS Events Recorded Underground

    Teuscher, R

    As reported in the CERN Bulletin, Issue No.30-31, 25 July 2005 The ATLAS barrel Tile calorimeter has recorded its first events underground using a cosmic ray trigger, as part of the detector commissioning programme. This is not a simulation! A cosmic ray muon recorded by the barrel Tile calorimeter of ATLAS on 21 June 2005 at 18:30. The calorimeter has three layers and a pointing geometry. The light trapezoids represent the energy deposited in the tiles of the calorimeter depicted as a thick disk. On the evening of June 21, the ATLAS detector, now being installed in the underground experimental hall UX15, reached an important psychological milestone: the barrel Tile calorimeter recorded the first cosmic ray events in the underground cavern. An estimated million cosmic muons enter the ATLAS cavern every 3 minutes, and the ATLAS team decided to make good use of some of them for the commissioning of the detector. Although only 8 of the 128 calorimeter slices ('superdrawers') were included in the trigg...

  3. Analytical Solution for the Current Distribution in Multistrand Superconducting Cables

    Bottura, L; Fabbri, M G

    2002-01-01

    Current distribution in multistrand superconducting cables can be a major concern for stability in superconducting magnets and for field quality in particle accelerator magnets. In this paper we describe multistrand superconducting cables by means of a distributed parameters circuit model. We derive a system of partial differential equations governing current distribution in the cable and we give the analytical solution of the general system. We then specialize the general solution to the particular case of uniform cable properties. In the particular case of a two-strand cable, we show that the analytical solution presented here is identical to the one already available in the literature. For a cable made of N equal strands we give a closed form solution that to our knowledge was never presented before. We finally validate the analytical solution by comparison to numerical results in the case of a step-like spatial distribution of the magnetic field over a short Rutherford cable, both in transient and steady ...

  4. Deployment/Retrieval Modeling of Cable-Driven Parallel Robot

    Q. J. Duan

    2010-01-01

    Full Text Available A steady-state dynamic model of a cable in air is put forward by using some tensor relations. For the dynamic motion of a long-span Cable-Driven Parallel Robot (CDPR system, a driven cable deployment and retrieval mathematical model of CDPR is developed by employing lumped mass method. The effects of cable mass are taken into account. The boundary condition of cable and initial values of equations is founded. The partial differential governing equation of each cable is thus transformed into a set of ordinary differential equations, which can be solved by adaptive Runge-Kutta algorithm. Simulation examples verify the effectiveness of the driven cable deployment and retrieval mathematical model of CDPR.

  5. RESPONSE CHARACTERISTICS OF WIND EXCITED CABLES WITH ARTIFICIAL RIVULET

    顾明; 刘慈军; 徐幼麟; 项海帆

    2002-01-01

    A wind tunnel investigation of response characteristics of cables with artificial rivulet is presented.A series of cable section models of different mass and stiffness and damping ratio were designed with artificial rivulet.They were tested in smooth flow under different wind speed and yaw angle and for different position of artificial rivulet.The measured response of cable models was then analyzed and compared with the experimental results obtained by other researchers and the existing theories for wind-induced cable vibration.The results show that the measured response of horizontal cable models with artificial rivulet could be well predicted by Den Hartog' s galloping theory when wind is normal to the cable axis.For the wind with certain yaw angles, the cable models with artificial rivulet exhibit velocity-restricted response characteristics.

  6. Design, manufacture, test and delivery of a 230 kV extruded irradiated crosslinked polyethylene cable. Final report

    None

    1978-01-01

    A project was initiated to develop a 230 kV solid dielectric cable for use in underground transmission. The dielectric is to be polyethylene, crosslinked by electron bombardment. Compared to the more conventional chemically crosslinked polyethylene, the irradiated cable is expected to contain less sensitive defects and thus be more suitable for a 230 kV rating. A toroidally shaped diode was developed to provide a uniform radiation dose to a thick-walled coaxial cable. The diode is to receive an output wave form obtained by ringing a Marx generator into a peaking capacitor. Initial evaluation of the toroidal diode was performed on thin plaques and tapes of insulating and semi-conducting polyethylene polymers. Additionally, some miscellaneous ethylene plastics were briefly investigated. Using a 4.8 MV Van de Graaff pulse generator in conjunction with several diode configurations, 15 to 35 kV extruded HMW-PE cables were irradiated. Dose rate, temperature, and pressure effects were evaluated. It was found that with limited dose rate it was possible to produce excellent crosslink density and uniformity at room temperature and atmospheric pressure. A subsequent 60 Hz voltage endurance test on an irradiated cable sample indicated it had long term, high stress capability. An engineering study conducted to determine an acceptable irradiator system design is reported. It was estimated that a 7 MV peak voltage at a rate of 2 to 3 pulse/sec can be provided by a Marx generator/peaking capacitor and should be capable of crosslinking a polyethylene wall thickness of approximately 2.5 cm. Based on the accumulated test results and on the performance of the 7 MV irradiator predicted, it appears feasible to continue the work effort into the next scheduled phase.

  7. AC/RF Superconductivity

    Ciovati, Gianluigi [JLAB

    2015-02-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  8. AC/RF Superconductivity

    Ciovati, G.

    2015-01-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  9. A Study on the System and Method for Drawing 3-Dimensional Cable Object with the cable tracking Navigation

    3D cable tracking system with navigation makes it possible to easily search the objects which users want to retrieve and to measure the visual, spatial and structural distance by connecting the existing cable management system with 3D cable tracking system with navigation. With this consideration, we hope to create a more advanced cable management system in the future. I would like to describes the management system and method of the cable installed in the nuclear power plant, and how to build the database of the system. More specifically, it will be operated to the maintenance and management function, and the life management system of the cable, describing the creation method of three-dimensional cable object formed by the information of trace route through navigation and how to build the system database automatically

  10. A Study on the System and Method for Drawing 3-Dimensional Cable Object with the cable tracking Navigation

    Bhang, Keugjin; Jung, Sunchul [Central Research Institute, Daejeon (Korea, Republic of); Hong, Junhee [Chungnam Univ., Daejeon (Korea, Republic of)

    2013-05-15

    3D cable tracking system with navigation makes it possible to easily search the objects which users want to retrieve and to measure the visual, spatial and structural distance by connecting the existing cable management system with 3D cable tracking system with navigation. With this consideration, we hope to create a more advanced cable management system in the future. I would like to describes the management system and method of the cable installed in the nuclear power plant, and how to build the database of the system. More specifically, it will be operated to the maintenance and management function, and the life management system of the cable, describing the creation method of three-dimensional cable object formed by the information of trace route through navigation and how to build the system database automatically.

  11. Offshore wind farm electrical cable layout optimization

    Pillai, A. C.; Chick, J.; Johanning, L.; Khorasanchi, M.; de Laleu, V.

    2015-12-01

    This article explores an automated approach for the efficient placement of substations and the design of an inter-array electrical collection network for an offshore wind farm through the minimization of the cost. To accomplish this, the problem is represented as a number of sub-problems that are solved in series using a combination of heuristic algorithms. The overall problem is first solved by clustering the turbines to generate valid substation positions. From this, a navigational mesh pathfinding algorithm based on Delaunay triangulation is applied to identify valid cable paths, which are then used in a mixed-integer linear programming problem to solve for a constrained capacitated minimum spanning tree considering all realistic constraints. The final tree that is produced represents the solution to the inter-array cable problem. This method is applied to a planned wind farm to illustrate the suitability of the approach and the resulting layout that is generated.

  12. Development of polymer packaging for power cable

    S. Sremac

    2014-10-01

    Full Text Available This paper discusses the issues of product design and the procedure of developing polymer packaging as one of the most important engineering tasks. For the purpose of packing power cables a polymer packaging has been designed in the form of drum. Packaging and many other consumer products are largely produced using polymeric materials due to many positive features. High Density Polyethylene is the type of polyethylene proposed for packaging purposes due to its low degree of branching and strong intermolecular forces. Transport and storage processes were automated based on the radio-frequency identification technology. The proposed system is flexible in terms of its possibility of accepting and processing different types of cables and other products.

  13. Aging assessment of cable for NPP

    Activation energy is measured with UTM (Universal Testing Machine), TGA (Thermo-gravimetric Analyzer) and DMA (Dynamic Mechanical Analyzer) to analyze the aging degree of cables for NPP (Nuclear Power Plant). Insulation power cables containing EPR (Ethylene Propylene Rubber) are arranged for two kinds of specimens which are intact specimens and aged specimens by exposing to LOCA (Loss of Coolant Accident) environmental conditions regulated in IEEE 323. In case of intact specimen, values of activation energy are 1.1 eV for UTM, 1.24 eV with storage modulus and 1.13 eV with loss modulus for DMA, 1.29 eV for TGA, respectively. Damping of specimen under LOCA conditions decreases the activation energy to 0.88 eV for TGA. (author)

  14. Horizon-T Experiment Calibrations - Cables

    Beznosko, D; Iakovlev, A; Makhataeva, Z; Vildanova, M I; Yelshibekov, K; Zhukov, V V

    2016-01-01

    An innovative detector system called Horizon-T is constructed to study Extensive Air Showers (EAS) in the energy range above 1016 eV coming from a wide range of zenith angles (0o - 85o). The system is located at Tien Shan high-altitude Science Station of Lebedev Physical Institute of the Russian Academy of Sciences at approximately 3340 meters above the sea level. The detector consists of eight charged particle detection points separated by the distance up to one kilometer as well as optical detector to view the Vavilov-\\v{C}erenkov light from the EAS. Each detector connects to the Data Acquisition system via cables. The calibration of the time delay for each cable and the signal attenuation is provided in this article.

  15. Underground siting is a nuclear option

    Underground siting of nuclear power plants is a concept that can be both technologically feasible and economically attractive. To meet both these criteria, however, each underground nuclear plant must be adapted to take full advantage of its location. It cannot be a unit that was designed for the surface and is then buried. Seeking to develop potential commercial programs, Underground Design Consultants (UDC)--a joint venture of Parsons, Brinckerhoff, Quade and Douglas, New York City, Vattenbyggnadsbyran (VBB), Stockholm, Sweden, and Foundation Sciences, Inc., Portland, Oregon--has been studying the siting of nuclear plants underground. UDC has made a presentation to EPRI on the potential for underground siting in the U.S. The summary presented here is based on the experiences of underground nuclear power plants in Halden, Norway; Agesta, Sweden; Chooz, France; and Lucens, Switzerland. Data from another plant in the design phase in Sweden and UDC's own considered judgment were also used

  16. Influence of strand surface condition on interstrand contact resistance and coupling loss in NbTi-wound Rutherford cables

    Sumption, M D; Scanlan, R M; Nijhuis, A; ten Kate, H H J; Kim, S W; Wake, M; Shintomi, T

    1999-01-01

    Presented in this work are the results of directly measured and AC- loss-derived interstrand contact resistance (ICR) measurements performed magnetically or resistively on bare-Cu and coated-strand pairs, calorimetrically on $9 11-strand Rutherford cables wound with strands that had been coated with various metallic and insulating layers, and calorimetrically and magnetically on 28-strand Rutherford cables (LHC-type) wound with bare-Cu-, Ni-, and $9 stabrite-plated strands. Comparisons are made of the effects of various conditions of heat treatment, HT (time and temperature), and pressure (applied during HT and then either maintained or re-applied during measurement). The $9 resulting ICRs are compared and interpreted in terms of the oxide layer on the strand coating and its response to curing conditions. (66 refs).

  17. Development of radiation resistant electrical cable insulations

    Two new polyethylene cable insulations have been formulated for nuclear applications, and have been tested under gamma radiation. Both insulations are based on low density polyethylene, one with PbO and the other with Sb2O3 as additives. The test results show that the concept of using inorganic antioxidants to retard radiation initiated oxidation (RIO) is viable. PbO is more effective than Sb2O3 in minimizing RIO

  18. Optical fibre cable selection for electricity utilities

    NONE

    2001-07-01

    The report provides an assessment of the range of optical fibre cable solutions available, by type e.g. OPGW, ADSS, rather than by design. it also examines the key issues which will influence an electricity utilities decisions and proposes a method of evaluating the options to identify the one which most closely matches the utility's critical needs, with measurements against time, cost and quality targets. (author)

  19. Ultrasonic security seal with a cable

    The sonic delay line of the seal is prolongated by a truncated part and terminated by a spherical cap which can be marked. The sealing capsule has a bore adapted to the size of the truncated part of the identity module. The sealing cable is fastened between the sealing capsule and the module. Application is made to the monitoring of containers for dangerous or radioactive materials

  20. Space charge fields in DC cables

    McAllister, Iain Wilson; Crichton, George C; Pedersen, Aage

    The space charge that accumulates in DC cables can, mathematically, be resolved into two components. One is related to the temperature and the other to the magnitude of the electric field strength. Analytical expressions for the electric fields arising from each of these space charge components are...... derived. Thereafter, the significance of these field components under both normal operating conditions and immediately following polarity reversal is discussed...

  1. Influence of Icing on Bridge Cable Aerodynamics

    Koss, Holger; Frej Henningsen, Jesper; Olsen, Idar

    2013-01-01

    determination of these force coefficients require a proper simulation of the ice layer occurring under the specific climatic conditions, favouring real ice accretion over simplified artificial reproduction. The work presented in this paper was performed to study the influence of ice accretion on the aerodynamic...... forces of different bridge cables types. The experiments were conducted in a wind tunnel facility capable amongst others to simulate incloud icing conditions....

  2. Automated wireless monitoring system for cable tension using smart sensors

    Sim, Sung-Han; Li, Jian; Jo, Hongki; Park, Jongwoong; Cho, Soojin; Spencer, Billie F.; Yun, Chung-Bang

    2013-04-01

    Cables are critical load carrying members of cable-stayed bridges; monitoring tension forces of the cables provides valuable information for SHM of the cable-stayed bridges. Monitoring systems for the cable tension can be efficiently realized using wireless smart sensors in conjunction with vibration-based cable tension estimation approaches. This study develops an automated cable tension monitoring system using MEMSIC's Imote2 smart sensors. An embedded data processing strategy is implemented on the Imote2-based wireless sensor network to calculate cable tensions using a vibration-based method, significantly reducing the wireless data transmission and associated power consumption. The autonomous operation of the monitoring system is achieved by AutoMonitor, a high-level coordinator application provided by the Illinois SHM Project Services Toolsuite. The monitoring system also features power harvesting enabled by solar panels attached to each sensor node and AutoMonitor for charging control. The proposed wireless system has been deployed on the Jindo Bridge, a cable-stayed bridge located in South Korea. Tension forces are autonomously monitored for 12 cables in the east, land side of the bridge, proving the validity and potential of the presented tension monitoring system for real-world applications.

  3. Causes and consequences of underground economy

    Mara, Eugenia-Ramona

    2011-01-01

    In this endeavor an attempt has been made to investigate the major causes and factors of influence of the underground economy. Our analysis is based on the study of tax payer behavior and taxation system pattern. The paper examines how social institutions and government policies affect underground economy. All these factors have an important impact on the level and size of underground economy and determine the consequences of this phenomenon.

  4. UNDERGROUND ECONOMY, GDP AND STOCK MARKET

    Caus Vasile Aurel

    2012-01-01

    Economic growth is affected by the size and dynamics of underground economy. Determining this size is a subject of research for many authors. In this paper we present the relationship between underground economy dynamics and the dynamics of stock markets. The observations are based on regression used by Tanzi (1983) and the relationship between GDP and stock market presented in Tudor (2008). The conclusion of this paper is that the dynamics of underground economy is influenced by dynamic of f...

  5. Transport Model of Underground Sediment in Soils

    Sun Jichao; Wang Guangqian

    2013-01-01

    Studies about sediment erosion were mainly concentrated on the river channel sediment, the terrestrial sediment, and the underground sediment. The transport process of underground sediment is studied in the paper. The concept of the flush potential sediment is founded. The transport equation with stable saturated seepage is set up, and the relations between the flush potential sediment and water sediment are discussed. Flushing of underground sediment begins with small particles, and large pa...

  6. Prospective barrier coatings for superconducting cables

    Ipatov, Y.; Dolgosheev, P.; Sytnikov, V.

    1997-07-01

    Known and prospective types of chromium coatings, used in the production of superconducting `cable-in-conduit' conductors designed for the ITER and other projects, are considered. The influence of the technological conditions during the galvanic plating of hard, grey, black and combined chromium coatings in various electrolytes and the annealing conditions in air and in vacuum on the contact electrical resistance of copper and superconducting wire at room temperature and 4.2 K as well as on other physical properties, e.g. resistance to abrasion, elasticity and thickness of the coatings, is investigated. Black oxide - chromium coatings and combined chromium coatings, containing oxides of chromium and a number of other metals, ensure the possibility of a significant increase of contact resistance as well as its regulation in a broad range of values in comparison with hard chromium. The results of the present work and also an independent investigation of the cable containing the strand, manufactured in JSC `VNIIKP', allow us to propose the oxide - chromium coating as a barrier layer for multistrand superconducting cables.

  7. Cable energy function of cortical axons.

    Ju, Huiwen; Hines, Michael L; Yu, Yuguo

    2016-01-01

    Accurate estimation of action potential (AP)-related metabolic cost is essential for understanding energetic constraints on brain connections and signaling processes. Most previous energy estimates of the AP were obtained using the Na(+)-counting method, which seriously limits accurate assessment of metabolic cost of ionic currents that underlie AP conduction along the axon. Here, we first derive a full cable energy function for cortical axons based on classic Hodgkin-Huxley (HH) neuronal equations and then apply the cable energy function to precisely estimate the energy consumption of AP conduction along axons with different geometric shapes. Our analytical approach predicts an inhomogeneous distribution of metabolic cost along an axon with either uniformly or nonuniformly distributed ion channels. The results show that the Na(+)-counting method severely underestimates energy cost in the cable model by 20-70%. AP propagation along axons that differ in length may require over 15% more energy per unit of axon area than that required by a point model. However, actual energy cost can vary greatly depending on axonal branching complexity, ion channel density distributions, and AP conduction states. We also infer that the metabolic rate (i.e. energy consumption rate) of cortical axonal branches as a function of spatial volume exhibits a 3/4 power law relationship. PMID:27439954

  8. Cable energy function of cortical axons

    Ju, Huiwen; Hines, Michael L.; Yu, Yuguo

    2016-01-01

    Accurate estimation of action potential (AP)-related metabolic cost is essential for understanding energetic constraints on brain connections and signaling processes. Most previous energy estimates of the AP were obtained using the Na+-counting method, which seriously limits accurate assessment of metabolic cost of ionic currents that underlie AP conduction along the axon. Here, we first derive a full cable energy function for cortical axons based on classic Hodgkin-Huxley (HH) neuronal equations and then apply the cable energy function to precisely estimate the energy consumption of AP conduction along axons with different geometric shapes. Our analytical approach predicts an inhomogeneous distribution of metabolic cost along an axon with either uniformly or nonuniformly distributed ion channels. The results show that the Na+-counting method severely underestimates energy cost in the cable model by 20–70%. AP propagation along axons that differ in length may require over 15% more energy per unit of axon area than that required by a point model. However, actual energy cost can vary greatly depending on axonal branching complexity, ion channel density distributions, and AP conduction states. We also infer that the metabolic rate (i.e. energy consumption rate) of cortical axonal branches as a function of spatial volume exhibits a 3/4 power law relationship. PMID:27439954

  9. The ANDES Deep Underground Laboratory

    Bertou, X

    2013-01-01

    ANDES (Agua Negra Deep Experiment Site) is a unique opportunity to build a deep underground laboratory in the southern hemisphere. It will be built in the Agua Negra tunnel planned between Argentina and Chile, and operated by the CLES, a Latin American consortium. With 1750m of rock overburden, and no close- by nuclear power plant, it will provide an extremely radiation quiet environment for neutrino and dark matter experiments. In particular, its location in the southern hemisphere should play a major role in understanding dark matter modulation signals.

  10. Third symposium on underground mining

    None

    1977-01-01

    The Third Symposium on Underground Mining was held at the Kentucky Fair and Exposition Center, Louisville, KY, October 18--20, 1977. Thirty-one papers have been entered individually into EDB and ERA. The topics covered include mining system (longwall, shortwall, room and pillar, etc.), mining equipment (continuous miners, longwall equipment, supports, roof bolters, shaft excavation equipment, monitoring and control systems. Maintenance and rebuilding facilities, lighting systems, etc.), ventilation, noise abatement, economics, accidents (cost), dust control and on-line computer systems. (LTN)

  11. Underground Shocks Ground Zero Responses

    Maurizio Bovi

    2004-01-01

    The aim of this paper is twofold. First, new annual data on Italian irregular sector for the period 1980-1991 are reconstructed. These data are compatible with the available 1992-2001 official data. Second, based on this self-consistent “long” sample a time series analysis of the two sides – the underground and the regular - of the Italian GDP is performed. Results from univariate and VAR models seem to suggest that there are no connections (causal relationship, feedbacks, contemporaneous cyc...

  12. Increased Ac excision (iae): Arabidopsis thaliana mutations affecting Ac transposition

    The maize transposable element Ac is highly active in the heterologous hosts tobacco and tomato, but shows very much reduced levels of activity in Arabidopsis. A mutagenesis experiment was undertaken with the aim of identifying Arabidopsis host factors responsible for the observed low levels of Ac activity. Seed from a line carrying a single copy of the Ac element inserted into the streptomycin phosphotransferase (SPT) reporter fusion, and which displayed typically low levels of Ac activity, were mutagenized using gamma rays. Nineteen mutants displaying high levels of somatic Ac activity, as judged by their highly variegated phenotypes, were isolated after screening the M2 generation on streptomycin-containing medium. The mutations fall into two complementation groups, iae1 and iae2, are unlinked to the SPT::Ac locus and segregate in a Mendelian fashion. The iae1 mutation is recessive and the iae2 mutation is semi-dominant. The iae1 and iae2 mutants show 550- and 70-fold increases, respectively, in the average number of Ac excision sectors per cotyledon. The IAE1 locus maps to chromosome 2, whereas the SPT::Ac reporter maps to chromosome 3. A molecular study of Ac activity in the iae1 mutant confirmed the very high levels of Ac excision predicted using the phenotypic assay, but revealed only low levels of Ac re-insertion. Analyses of germinal transposition in the iae1 mutant demonstrated an average germinal excision frequency of 3% and a frequency of independent Ac re-insertions following germinal excision of 22%. The iae mutants represents a possible means of improving the efficiency of Ac/Ds transposon tagging systems in Arabidopsis, and will enable the dissection of host involvement in Ac transposition and the mechanisms employed for controlling transposable element activity

  13. 30 CFR 57.8519 - Underground main fan controls.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground main fan controls. 57.8519 Section... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Surface and Underground § 57.8519 Underground main fan controls. All underground main fans...

  14. Rapid optimization of tension distribution for cable-driven parallel manipulators with redundant cables

    Ouyang, Bo; Shang, Weiwei

    2016-03-01

    The solution of tension distributions is infinite for cable-driven parallel manipulators(CDPMs) with redundant cables. A rapid optimization method for determining the optimal tension distribution is presented. The new optimization method is primarily based on the geometry properties of a polyhedron and convex analysis. The computational efficiency of the optimization method is improved by the designed projection algorithm, and a fast algorithm is proposed to determine which two of the lines are intersected at the optimal point. Moreover, a method for avoiding the operating point on the lower tension limit is developed. Simulation experiments are implemented on a six degree-of-freedom(6-DOF) CDPM with eight cables, and the results indicate that the new method is one order of magnitude faster than the standard simplex method. The optimal distribution of tension distribution is thus rapidly established on real-time by the proposed method.

  15. Hermetisk AC-Krets

    Hirsch, Carl; Smirnoff, Alexander

    2007-01-01

    Under sex månader våren 2007 har ett samarbete mellan Volvo Lastvagnar och två studenter från KTH, inriktning Integrerad produktutveckling vid institutionen för maskinkonstruktion, pågått i form av ett examensarbete på 20 poäng. Dagens AC-system i Volvos lastbilar avger 20-40 g/år av köldmediet R134a som är en kraftfull växthusgas. Detta sker främst genom diffusion via slangar och tätningsmaterial. Syftet med detta examensarbete är att ta fram förslag på tekniska lösningar på ett nytt AC-syst...

  16. Numerical method of thermal design of power cables

    Bryukhanov, O.N.; Trigorlyy, S.V.

    1985-05-01

    Increasing the accuracy of computation of permissible current loads in cables requires that thermal calculations be performed considering the actual distribution of temperatures in the cables. An analysis of methods of thermal design of cables showed that numerical methods allowing most complete consideration of various heat exchange factors are superior. The authors suggest the use of the method of finite elements to study thermal states of multiple-conductor power cables laid in various ways. As an example, thermal calculation of three-conductor cable with circular conductors is studied. For a number of cables the permissible current loads calculated by the method of finite elements are greater than those established by the standards documents of calculated according to previous methods.

  17. Aging assessment of electrical cables from NPD nuclear generating station

    Degradation of NPD Nuclear Generating Station control and power cables after approximately 25 years of service was assessed. The PVC and SBR insulated cables were also exposed to radiation, accident and post-accident conditions, and accelerated aging to simulate extended service life. The degradation of the samples from the containment boiler room was minimal, caused mainly by thermal conditions rather than radiation. Although irradiation to 55 Mrad, simulating normal operation and accident radiation levels, caused degradation, the cables could still function during accident and post-accident conditions. Accelerated thermal aging to simulate an additional 10 years of service at 45 degrees C caused embrittlement of the PVC and a 60% decrease in elongation of the SBR. Comparison of test results of aged NPD cables with newer PVC cables obtained from Pickering NGS 'A' shows that the newer cables have improved aging stability and therefore should provide adequate service during their design life of 31 years

  18. Optimization and stability of a cable-in-conduit superconductor

    The optimization process for strand number and diameter, cable void fraction, and Cu/NbTi-ratio of the cable-in-conduit conductor for the superconducting magnet system of the planned stellarator fusion experiment Wendelstein 7-X is presented. Main optimization criteria are stability and cable cooling requirements, taking into account transient disturbances and losses. A simple stability criterion regarding transient disturbances is used which is derived from cable compression experiments. The resulting data for the 16 kA, 6 T cable are: cable and strand diameter ∼11.5 mm and ∼0.57 mm, respectively, strand number ∼250, void ∼36%, and Cu/sc-ratio ∼2.7

  19. Dynamic behavior of stay cables with passive negative stiffness dampers

    Shi, Xiang; Zhu, Songye; Li, Jin-Yang; Spencer, Billie F., Jr.

    2016-07-01

    This paper systematically investigates the dynamic behavior of stay cables with passive negative stiffness dampers (NSD) installed close to the cable end. A passive NSD is modeled as a combination of a negative stiffness spring and a viscous damper. Through both analytical and numerical approaches, parametric analysis of negative stiffness and viscous damping are conducted to systematically evaluate the vibration control performance of passive NSD on stay cables. Since negative stiffness is an unstable element, the boundary of passive negative stiffness for stay cables to maintain stability is also derived. Results reveal that the asymptotic approach is only applicable to passive dampers with positive or moderate negative stiffness, and loses its accuracy when a passive NSD possesses significant negative stiffness. It has been found that the performance of passive NSD can be much better than those of conventional viscous dampers. The superior control performance of passive NSD in cable vibration mitigation is validated through numerical simulations of a full-scale stay cable.

  20. Analytical dynamic solution of a flexible cable-suspended manipulator

    Bamdad, Mahdi

    2013-12-01

    Cable-suspended manipulators are used in large scale applications with, heavy in weight and long in span cables. It seems impractical to maintain cable assumptions of smaller robots for large scale manipulators. The interactions among the cables, platforms and actuators can fully evaluate the coupled dynamic analysis. The structural flexibility of the cables becomes more pronounced in large manipulators. In this paper, an analytic solution is provided to solve cable vibration. Also, a closed form solution can be adopted to improve the dynamic response to flexibility. The output is provided by the optimal torque generation subject to the actuator limitations in a mechatronic sense. Finally, the performance of the proposed algorithm is examined through simulations.

  1. Antenna mechanism of length control of actin cables

    Mohapatra, Lishibanya; Kondev, Jane

    2014-01-01

    Actin cables are linear cytoskeletal structures that serve as tracks for myosin-based intracellular transport of vesicles and organelles in both yeast and mammalian cells. In a yeast cell undergoing budding, cables are in constant dynamic turnover yet some cables grow from the bud neck toward the back of the mother cell until their length roughly equals the diameter of the mother cell. This raises the question: how is the length of these cables controlled? Here we describe a novel molecular mechanism for cable length control inspired by recent experimental observations in cells. This antenna mechanism involves three key proteins: formins, which polymerize actin, Smy1 proteins, which bind formins and inhibit actin polymerization, and myosin motors, which deliver Smy1 to formins, leading to a length-dependent actin polymerization rate. We compute the probability distribution of cable lengths as a function of several experimentally tuneable parameters such as the formin-binding affinity of Smy1 and the concentra...

  2. Transverse stress effects in Nb3Sn cables

    The effect of transverse compressive stress on the critical current of solder-filled and unfilled Nb3Sn cables is reported. The conductor used in this study is a Nb3Sn Rutherford cable manufactured with a bronze-process wire of 0.92 mm diameter. Like epoxy-impregnated cables, solder-filled cables exhibit much less degradation than wire samples when subjected to the same stresses. On the other hand, unfilled specimens are irreversibly damaged at the thin edge when loaded to 160 MPa, and show significantly higher degradation than similar specimens of the solder-filled cable. A finite-element calculation of the stress state inside a particular composite superconductor indicates that more compressive stress is developed in the virgin wire than in a straight wire segment in a real cable environment

  3. Optical Fiber Grating Sensor for Force Measurement of Anchor Cable

    JIANG Desheng; FU Jinghua; LIU Shengchun; SUI Lingfeng; FU Rong

    2006-01-01

    The development of the sensor suitable for measuring large load stress to the anchor cable becomes an important task in bridge construction and maintenance. Therefore, a new type of optical fiber sensor was developed in the laboratory - optical fiber grating sensor for force measurement of anchor cable (OFBFMAC). No similar report about this kind of sensor has been found up to now in China and other countries. This sensor is proved to be an effective way of monitoring in processes of anchor cable installation, cable cutting, cable force regulation, etc, with the accurate and repeatable measuring results. Its successful application in the tie bar cable force safety monitoring for Wuhan Qingchuan bridge is a new exploration of optical fiber grating sensing technology in bridge tie bar monitoring system.

  4. The Coupling Effect of Spatial Reticulated Shell Structure with Cables

    MA Jun; ZHOU Dai; FU Xu-chen

    2005-01-01

    The spatial reticulated shell structure with cables (RSC) is a kind of coupling working system, which consists of flexible cables, reticulated shell structure (RS) and tower columns. The dynamic analysis of RSC based on the coupling model was carried out. Three kinds of elements such as the spatial bar element, cable element and beam element were introduced to analyze the reticulated shell, cable and tower column respectively. Furthermore,such parameter influences as structural boundary conditions, grid configuration, the span-to-depth ratio and the arrangement of cable system upon structural dynamics were analyzed. The structural vibration modes can be divided into four groups based on some numerical examples. And the frequencies in the same group are very close while the frequencies in different groups are different from each other obviously. It is clear that the sequence of the appearance of the each mode group heavily depends on the comparative stiffness of the tower column system, RS and cables.

  5. Study on the Configuration of Towed Flexible Cables

    陈敏康; 张仁颐

    2003-01-01

    Based on the fundamental equation of flexible cable dynamics for a towed system, an easily solved mathematical model is set up in this paper by means of appropriate simplification. Several regular patterns of spatial motion of towed flexible cables in water are obtained through numerical simulation with the finite difference method, and then modification and verification by trial results at sea. A technical support is provided for the towing ship to maneuver properly when a flexible cable is towed. Furthermore, the relations between two towed flexible cables, which are towed simultaneously by a ship, are investigated. The results show that the ship towing two flexible cables is safe under the suggested arrangement of two winches for the towing system, and the coiling/uncoiling sequences of the cables as well as the suggested way of maneuvering.

  6. Underground repository for radioactive wastes

    In the feasibility study for an underground repository in Argentina, the conceptual basis for the final disposal of high activity nuclear waste was set, as well as the biosphere isolation, according to the multiple barrier concept or to the engineering barrier system. As design limit, the container shall act as an engineering barrier, granting the isolation of the radionuclides for approximately 1000 years. The container for reprocessed and vitrified wastes shall have three metallic layers: a stainless steel inner layer, an external one of a metal to be selected and a thick intermediate lead layer preselected due to its good radiological protection and corrosion resistance. Therefore, the study of the lead corrosion behaviour in simulated media of an underground repository becomes necessary. Relevant parameters of the repository system such as temperature, pressure, water flux, variation in salt concentrations and oxidants supply shall be considered. At the same time, a study is necessary on the galvanic effect of lead coupled with different candidate metals for external layer of the container in the same experimental conditions. Also temporal evaluation about the engineering barrier system efficiency is presented in this thesis. It was considered the extrapolated results of corrosion rates and literature data about the other engineering barriers. Taking into account that corrosion is of a generalized type, the integrity of the lead shall be maintained for more than 1000 years and according to temporal evaluation, the multiple barrier concept shall retard the radionuclide dispersion to the biosphere for a period of time between 104 and 106 years. (Author)

  7. Underground storage tank management plan

    The Underground Storage Tank (UST) Management Program at the Oak Ridge Y-12 Plant was established to locate UST systems in operation at the facility, to ensure that all operating UST systems are free of leaks, and to establish a program for the removal of unnecessary UST systems and upgrade of UST systems that continue to be needed. The program implements an integrated approach to the management of UST systems, with each system evaluated against the same requirements and regulations. A common approach is employed, in accordance with Tennessee Department of Environment and Conservation (TDEC) regulations and guidance, when corrective action is mandated. This Management Plan outlines the compliance issues that must be addressed by the UST Management Program, reviews the current UST inventory and compliance approach, and presents the status and planned activities associated with each UST system. The UST Management Plan provides guidance for implementing TDEC regulations and guidelines for petroleum UST systems. (There are no underground radioactive waste UST systems located at Y-12.) The plan is divided into four major sections: (1) regulatory requirements, (2) implementation requirements, (3) Y-12 Plant UST Program inventory sites, and (4) UST waste management practices. These sections describe in detail the applicable regulatory drivers, the UST sites addressed under the Management Program, and the procedures and guidance used for compliance with applicable regulations

  8. Earthquake damage to underground facilities

    The potential seismic risk for an underground nuclear waste repository will be one of the considerations in evaluating its ultimate location. However, the risk to subsurface facilities cannot be judged by applying intensity ratings derived from the surface effects of an earthquake. A literature review and analysis were performed to document the damage and non-damage due to earthquakes to underground facilities. Damage from earthquakes to tunnels, s, and wells and damage (rock bursts) from mining operations were investigated. Damage from documented nuclear events was also included in the study where applicable. There are very few data on damage in the subsurface due to earthquakes. This fact itself attests to the lessened effect of earthquakes in the subsurface because mines exist in areas where strong earthquakes have done extensive surface damage. More damage is reported in shallow tunnels near the surface than in deep mines. In mines and tunnels, large displacements occur primarily along pre-existing faults and fractures or at the surface entrance to these facilities.Data indicate vertical structures such as wells and shafts are less susceptible to damage than surface facilities. More analysis is required before seismic criteria can be formulated for the siting of a nuclear waste repository

  9. Underground storage tank management plan

    NONE

    1994-09-01

    The Underground Storage Tank (UST) Management Program at the Oak Ridge Y-12 Plant was established to locate UST systems in operation at the facility, to ensure that all operating UST systems are free of leaks, and to establish a program for the removal of unnecessary UST systems and upgrade of UST systems that continue to be needed. The program implements an integrated approach to the management of UST systems, with each system evaluated against the same requirements and regulations. A common approach is employed, in accordance with Tennessee Department of Environment and Conservation (TDEC) regulations and guidance, when corrective action is mandated. This Management Plan outlines the compliance issues that must be addressed by the UST Management Program, reviews the current UST inventory and compliance approach, and presents the status and planned activities associated with each UST system. The UST Management Plan provides guidance for implementing TDEC regulations and guidelines for petroleum UST systems. (There are no underground radioactive waste UST systems located at Y-12.) The plan is divided into four major sections: (1) regulatory requirements, (2) implementation requirements, (3) Y-12 Plant UST Program inventory sites, and (4) UST waste management practices. These sections describe in detail the applicable regulatory drivers, the UST sites addressed under the Management Program, and the procedures and guidance used for compliance with applicable regulations.

  10. AC HTS Transmission Cable for Integration into the Future EHV Grid of the Netherlands

    Zuijderduin, R.; Chevtchenko, O.; Smit, J.J.; Aanhaanen, G.; Melnik, I.; Geschiere, A.

    2012-01-01

    Due to increasing power demand, the electricity grid of the Netherlands is changing. The future grid must be capable to transmit all the connected power. Power generation will be more decentralized like for instance wind parks connected to the grid. Furthermore, future large scale production units a

  11. DC Cable Short Circuit Fault Protection in VSC-MTDC

    Lu, Shining

    2015-01-01

    With the development of offshore wind farms, Voltage Source Converter based High Voltage Direct Current or Multi-terminal High Voltage Direct Current Technology (VSC-HVDC/MTDC) is becoming promising in the field of large-capacity and long-distance power transmission. However, its extreme vulnerability to DC contingencies remains a challenge in both research and practice. DC cable short circuit faults, or cable pole-to-pole faults, though less common than DC cable ground faults, can cause the ...

  12. 46 CFR 111.60-6 - Fiber optic cable.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Fiber optic cable. 111.60-6 Section 111.60-6 Shipping... REQUIREMENTS Wiring Materials and Methods § 111.60-6 Fiber optic cable. Each fiber optic cable must— (a) Be... 60332-3-22 (all three standards incorporated by reference; see 46 CFR 110.10-1); or (b) Be installed...

  13. Similarity Analysis of Cable Insulations by Chemical Test

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials

  14. Total Magnetic Field Signatures over Submarine HVDC Power Cables

    Johnson, R. M.; Tchernychev, M.; Johnston, J. M.; Tryggestad, J.

    2013-12-01

    Mikhail Tchernychev, Geometrics, Inc. Ross Johnson, Geometrics, Inc. Jeff Johnston, Geometrics, Inc. High Voltage Direct Current (HVDC) technology is widely used to transmit electrical power over considerable distances using submarine cables. The most commonly known examples are the HVDC cable between Italy and Greece (160 km), Victoria-Tasmania (300 km), New Jersey - Long Island (82 km) and the Transbay cable (Pittsburg, California - San-Francisco). These cables are inspected periodically and their location and burial depth verified. This inspection applies to live and idle cables; in particular a survey company could be required to locate pieces of a dead cable for subsequent removal from the sea floor. Most HVDC cables produce a constant magnetic field; therefore one of the possible survey tools would be Marine Total Field Magnetometer. We present mathematical expressions of the expected magnetic fields and compare them with fields observed during actual surveys. We also compare these anomalies fields with magnetic fields produced by other long objects, such as submarine pipelines The data processing techniques are discussed. There include the use of Analytic Signal and direct modeling of Total Magnetic Field. The Analytic Signal analysis can be adapted using ground truth where available, but the total field allows better discrimination of the cable parameters, in particular to distinguish between live and idle cable. Use of a Transverse Gradiometer (TVG) allows for easy discrimination between cable and pipe line objects. Considerable magnetic gradient is present in the case of a pipeline whereas there is less gradient for the DC power cable. Thus the TVG is used to validate assumptions made during the data interpretation process. Data obtained during the TVG surveys suggest that the magnetic field of a live HVDC cable is described by an expression for two infinite long wires carrying current in opposite directions.

  15. A linear model of stationary elevator traveling and compensation cables

    Zhu, W. D.; Ren, H.

    2013-06-01

    Based on a recent asymptotic analysis of a nonlinear model of a slack cable, a computationally efficient, linear model is developed for calculating the natural frequencies, mode shapes, and dynamic responses of stationary elevator traveling and compensation cables. The linear cable model consists of two vertical cable segments connected by a half-circular lower loop. The two vertical cable segments are modeled as a string with a variable tension due to the weight of the cable. The horizontal displacements of the cable segments consist of boundary-induced displacements and relative elastic displacements, where the boundary-induced displacements are interpolated from the displacements of the two lower ends of the cable segments, and the relative elastic displacements satisfy the corresponding homogeneous boundary conditions of the cable segments. The horizontal displacement of the lower loop is interpolated from those of the two lower ends of the two cable segments, and the bending stiffness of the lower loop is modeled by a spring with a constant stiffness, which can be calculated from the nonlinear model. Given a car position, the natural frequencies and mode shapes of an elevator traveling or compensation cable are calculated using the linear model and compared with those from the nonlinear model. The calculated natural frequencies are also compared with those from a full-scale experiment. In addition, the dynamic responses of a cable under a boundary excitation are calculated and compared with those from the nonlinear model. There is a good agreement between the predictions from the linear and nonlinear models and between the measured natural frequencies from the full-scale experiment and the corresponding calculated ones.

  16. Similarity Analysis of Cable Insulations by Chemical Test

    Kim, Jong Seog [Central Research Institute of Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2013-10-15

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials.

  17. Prospects of Research on Cable Logging in Forest Engineering Community

    Cavalli, Raffaele

    2012-01-01

    An analysis of researches on cable logging carried out in the past 12 years (2000–2011) as found in the scientific literature at international level is proposed in order to evaluate which have been the main topics of interest of the researchers and to evaluate the evolution of the research in the field of cable logging in the next future. International scientific literature on cable logging was extracted from the main databases, scientific journals and conference proceedings on forest enginee...

  18. Underwater-cable power-transmission system: bottom segment design

    1978-11-01

    After a survey of the state of the art for bottom cables, some possible configurations are considered for candidate OTEC sites. General considerations on laying and embedding are discussed, and solutions are considered. Optimization of cable dimensions and the problem of flexible joints are covered. The state of the art of cable installation and repair is reviewed and discussed with reference to the representative OTEC sites. Costs for shore terminal stations are evaluated. (LEW)

  19. Demand Pull and Supply Push in Portuguese Cable Television

    João Leitão

    2004-01-01

    In this paper a Vector Autoregressive Model is applied to the most representative Portuguese cable television operators, in order to obtain a dynamic analysis of the interactivity established between the supply and the demand of network services, through the strategy of vertical integration of services. The results reveal the existence of two driving forces in the Portuguese main cable networks, on the one hand, the supply push which contributes to the enhancement of the basic cable demand, a...

  20. Losses in armoured three-phase submarine cables

    Ebdrup, Thomas; Silva, Filipe Miguel Faria da; Bak, Claus Leth;

    2014-01-01

    The number of offshore wind farms will keep increasing in the future as a part of the shift towards a CO2 free energy production. The energy harvested from the wind farm must be brought to shore, which is often done by using a three-phase armoured submarine power cable. The use of an armour...... increases the losses in armoured cables compared to unarmoured cables. In this paper a thorough state of the art analysis is conducted on armour losses in three-phase armoured submarine power cables. The analysis shows that the IEC 60287-1-1 standard overestimates the armour losses which lead to the...

  1. Magnetic Flux Leakage Sensing-Based Steel Cable NDE Technique

    Seunghee Park

    2014-01-01

    Full Text Available Nondestructive evaluation (NDE of steel cables in long span bridges is necessary to prevent structural failure. Thus, an automated cable monitoring system is proposed that uses a suitable NDE technique and a cable-climbing robot. A magnetic flux leakage- (MFL- based inspection system was applied to monitor the condition of cables. This inspection system measures magnetic flux to detect the local faults (LF of steel cable. To verify the feasibility of the proposed damage detection technique, an 8-channel MFL sensor head prototype was designed and fabricated. A steel cable bunch specimen with several types of damage was fabricated and scanned by the MFL sensor head to measure the magnetic flux density of the specimen. To interpret the condition of the steel cable, magnetic flux signals were used to determine the locations of the flaws and the levels of damage. Measured signals from the damaged specimen were compared with thresholds that were set for objective decision-making. In addition, the measured magnetic flux signals were visualized as a 3D MFL map for intuitive cable monitoring. Finally, the results were compared with information on actual inflicted damages, to confirm the accuracy and effectiveness of the proposed cable monitoring method.

  2. Modeling and Experiments of Spray System for Cable Painting Robot

    ZHANG Jia-liang; Lü Tian-sheng; LI Bei-zhi

    2008-01-01

    Many cable-stayed bridges have been built in the world in the past decades,and cable-stayed structures have been adopted in many large constructions.The cable painting robot is safe and economically efficient for stay cable maintenance.In order to satisfy the need for spraying cables in hiigh attitude,an automatic cable spray system for cable painting robots is presented in this paper.Using the βdistribution,paint thickness distribution on a cylinder surface is modeled.The spray gun's number,angle and movement are analyzed to get coat evenness.Then a robotic spray system engineering prototype has been developed,which includes a cable electric running climbing base,a spray cover,four airless spray guns and a pressurized paint container.Experiments indicate that four airless spray guns can guarantee good coat quality for general stay cables.The field tests have been successfully conducted on Nanpu Bridge,Shanghai.

  3. Modelling Subsea Coaxial Cable as FIR Filter on MATLAB

    Kanisin, D.; Nordin, M. S.; Hazrul, M. H.; Kumar, E. A.

    2011-05-01

    The paper presents the modelling of subsea coaxial cable as a FIR filter on MATLAB. The subsea coaxial cables are commonly used in telecommunication industry and, oil and gas industry. Furthermore, this cable is unlike a filter circuit, which is a "lumped network" as individual components appear as discrete items. Therefore, a subsea coaxial network can be represented as a digital filter. In overall, the study has been conducted using MATLAB to model the subsea coaxial channel model base on primary and secondary parameters of subsea coaxial cable.

  4. Research on Cable Assembly Technology Facing Tridimention Layout in Spacecraft

    Song, Xiaohui; Liu, Zhe; Wang, Zaicheng; Zhang, Yidan; Zhang, Jie; Liu, Zhibin

    According to the requirement for cables tridimensional layout in spacecraft, the research on new transmission line support (NTLS) is carried out. NTLS is namely T support. Based on the analysis of NTLS's physical parameters, the scheme of cable installing is established. Experimentations of statics and vibration prove the feasibility and dependability of the scheme. The results of experimentation indicate that the scheme of cable installing on T support is reasonable along with the requirement of cables tridimensional layout is satisfied. Therefore the efficiency of spacecraft assembly and integration is greatly enhanced.

  5. Strand critical current degradation in $Nb_{3}$ Sn Rutherford cables

    Barzi, E; Higley, H C; Scanlan, R M; Yamada, R; Zlobin, A V

    2001-01-01

    Fermilab is developing 11 Tesla superconducting accelerator magnets based on Nb/sub 3/Sn superconductor. Multifilamentary Nb/sub 3/Sn strands produced using the modified jelly roll, internal tin, and powder-in-tube technologies were used for the development and test of the prototype cable. To optimize the cable geometry with respect to the critical current, short samples of Rutherford cable with packing factors in the 85 to 95% range were fabricated and studied. In this paper, the results of measurements of critical current, n-value and RRR made on the round virgin strands and on the strands extracted from the cable samples are presented. (5 refs).

  6. Development mineral insulated cables for nuclear instrumentation of reactors

    In-core and out-of-core neutron detectors for reactor and safety control systems are usually connected by means of mineral insulated cables. The electrical signal, either a pulse or a current, is transmitted along the cable at high temperature, pressure and radiation and should not be influenced by electromagnetic interfereces from the environment. In this paper it is presented the result of the analysis of the mechanical and electrical properties of several types of mineral insulated cables and also the design, manufacture, sealing, cable ends and their applications to nuclear detectors of various types. (author)

  7. BEHAVIOR OF ELASTIC TOWING CABLES IN SHEAR CURRENTS

    HOU Guo-xiang; LI Hong-bin; ZHANG Sheng-jun; YANG Yun-tao; XU Shi-hua; XIE Wei

    2005-01-01

    The formulation and solution of governing equations that can be used to analyse the three-dimensional behaviour of elastic towing cables subjected to arbitrary sheared currents were presented in this paper. The elastic cable geometry was described in terms of two angles, elevation and azimuth, which are related to Cartesian co-ordinates by geometry compatibility relations. These relations were combined with the cable equilibrium equations to obtain a system of non-linear differential equations. In the end, results for cable tension, angles, geometry and elongation are presented for example cases.

  8. 30 CFR 57.20031 - Blasting underground in hazardous areas.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Blasting underground in hazardous areas. 57... MINES Miscellaneous § 57.20031 Blasting underground in hazardous areas. In underground areas where... removed to safe places before blasting....

  9. Technologies for placing of underground installations

    Doneva, Nikolinka; Despodov, Zoran; Mirakovski, Dejan; Hadzi-Nikolova, Marija

    2014-01-01

    In urban communities often there is a need to change existing underground installations or placing new ones. This paper will discuss two technologies for placing underground installations including: classic and contemporary technology (technology with mechanical excavation). For each of these two technologies will be given advantages and disadvantages, as well as experiences from their application.

  10. UNDERGROUND ECONOMY, INFLUENCES ON NATIONAL ECONOMIES

    CEAUȘESCU IONUT

    2015-01-01

    The purpose of research is to improve the understanding of nature underground economy by rational justification of the right to be enshrined a reality that, at least statistically, can no longer be neglected. So, we propose to find the answer to the question: has underground economy to stand-alone?

  11. Underground location of nuclear power stations

    In Japan where the population is dense and the land is narrow, the conventional location of nuclear power stations on the ground will become very difficult sooner or later. At this time, it is very important to establish the new location method such as underground location, Quaternary ground location and offshore location as the method of expanding the location for nuclear power stations from the viewpoint of the long term demand and supply of electric power. As for underground location, the technology of constructing an underground cavity has been already fostered basically by the construction of large scale cavities for underground pumping-up power stations in the last 20 years. In France, Norway and Sweden, there are the examples of the construction of underground nuclear power stations. In this way, the opportunity of the underground location and construction of nuclear power stations seems to be sufficiently heightened, and the basic research has been carried out also in the Central Research Institute of Electric Power Industry. In this paper, as to underground nuclear power stations as one of the forms of utilizing underground space, the concept, the advantage in aseismatic capability, the safety at the time of a supposed accident, and the economical efficiency are discussed. (Kako, I.)

  12. UNDERGROUND ECONOMY, INFLUENCES ON NATIONAL ECONOMIES

    CEAUȘESCU IONUT

    2015-04-01

    Full Text Available The purpose of research is to improve the understanding of nature underground economy by rational justification of the right to be enshrined a reality that, at least statistically, can no longer be neglected. So, we propose to find the answer to the question: has underground economy to stand-alone?

  13. Overview of the European Underground Facilities

    Pandola, L

    2011-01-01

    Deep underground laboratories are the only places where the extremely low background radiation level required for most experiments looking for rare events in physics and astroparticle physics can be achieved. Underground sites are also the most suitable location for very low background gamma-ray spectrometers, able to assay trace radioactive contaminants. Many operational infrastructures are already available worldwide for science, differing for depth, dimension and rock characteristics. Other underground sites are emerging as potential new laboratories. In this paper the European underground sites are reviewed, giving a particular emphasis on their relative strength and complementarity. A coordination and integration effort among the European Union underground infrastructures was initiated by the EU-funded ILIAS project and proved to be very effective.

  14. Comparison of FT-IR and NIR method for cable classification

    There are about 50,000 cables in NPP. The number of the cables need to be environmentally qualified are 1,000 cables to 3,000 cables depending on the NPP respectively. Some EQ cables are environmentally qualified and the steam test reports prepared, but some other EQ cables are not environmentally qualified or not prepared steam test reports. Not qualified EQ cables need to be qualified by steam test; high temperature and high pressure with the same condition of DBAs. There are thousands of EQ cables in NPP but all the EQ cables don't have to be tested entirely. The steam tests can be carried out by the same types of cables. One type of cable is tested and demonstrated that the cable's capability for the duration of the installed life, all the same type of cables are qualified. Therefore, the classification the EQ cables is very important to carry out the steam test effectively. Also cable classification method selection is important, too. I tried two kinds of methods to classify the Wolsong Unit 1 EQ cables, Near InfraRed (NIR) spectroscopy and Fourier Transform InfraRed (FT-IR) spectroscopy. In case of old NPPs, lots of cables are missing their material information or have the wrong material information. The two methods are capable of searching for the material information of the cable. Briefly, the purpose FT-IR and NIR scanning is to find out their material information and classification of the EQ cables

  15. Development of a low-cost cableless geophone and its application in a micro-seismic survey at an abandoned underground coal mine

    Dai, Kaoshan; Li, Xiaofeng; Lu, Chuan; You, Qingyu; Huang, Zhenhua; Wu, H. Felix

    2015-04-01

    Due to the urbanization in China, some building construction sites are planned on areas above abandoned underground mines, which pose a concern for the stability of these sites and a critical need for the use of reliable site investigations. The array-based surface wave method has the potential for conducting large-scale field surveys at areas above underground mines. However, the dense deployment of conventional geophones requires heavy digital cables. On the other hand, the bulky and expensive standard stand-alone seismometers limit the number of stations for the array-based surface wave measurements. Therefore, this study developed a low-cost cableless geophone system for the array-based surface wave survey. A field case study using this novel cableless geophone system was conducted at an abandoned underground mine site in China to validate its functionality.

  16. Chemical-Sensing Cables Detect Potential Threats

    2007-01-01

    Intelligent Optical Systems Inc. (IOS) completed Phase I and II Small Business Innovation Research (SBIR) contracts with NASA's Langley Research Center to develop moisture- and pH-sensitive sensors to detect corrosion or pre-corrosive conditions, warning of potentially dangerous conditions before significant structural damage occurs. This new type of sensor uses a specially manufactured optical fiber whose entire length is chemically sensitive, changing color in response to contact with its target, and demonstrated to detect potentially corrosive moisture incursions to within 2 cm. After completing the work with NASA, the company received a Defense Advanced Research Projects Agency (DARPA) Phase III SBIR to develop the sensors further for detecting chemical warfare agents, for which they proved just as successful. The company then worked with the U.S. Department of Defense (DoD) to fine tune the sensors for detecting potential threats, such as toxic industrial compounds and nerve agents. In addition to the work with government agencies, Intelligent Optical Systems has sold the chemically sensitive fiber optic cables to major automotive and aerospace companies, who are finding a variety of uses for the devices. Marketed under the brand name Distributed Intrinsic Chemical Agent Sensing and Transmission (DICAST), these unique continuous-cable fiber optic chemical sensors can serve in a variety of applications: Corrosive-condition monitoring, aiding experimentation with nontraditional power sources, as an economical means of detecting chemical release in large facilities, as an inexpensive "alarm" systems to alert the user to a change in the chemical environment anywhere along the cable, or in distance-resolved optical time domain reflectometry systems to provide detailed profiles of chemical concentration versus length.

  17. The technology of cable and cable fault locating : part 4, high voltage non persistent fault finding

    Parker, G. [Radiodetection Ltd., Calgary, AB (Canada)

    2001-04-01

    The use of high voltage surge generators known as 'thumpers' was discussed in this last of a four part series on cable and fault locating technologies. The thumper is a portable source of high voltage, which repeatedly connects high voltage to a buried cable under test (CUT). The problem often associated with thumpers is that different ground conditions, vehicle traffic patters and fault types can make the noise they generate difficult to discern. In addition, repeated thumping can have negative side effects to the CUT, including weakening of adjacent cables. Thumped cables also fail prematurely, therefore thumping should be used only as a last resort. Advancements in thumper systems have included better listening devices, and the integration of safety systems, self-discharge systems, grounding, manual discharge hot-sticks, key switch lockouts and other methods to minimize injury. Other advancements have included a visual pre-locator which made the thumper more like a high voltage TDR. Pre-locators usually indicate the fault with an accuracy of 10 to 15 per cent. The Secondary Impulse Method (SIM) is the latest development in thumper technology. It was developed mainly to enhance trace interpretation. 2 figs.

  18. Performances of super-long span prestressed cable-stayed bridge with CFRP cables and RPC girder

    Fang Zhi; Fan Fenghong; Ren Liang

    2013-01-01

    To discuss the applicability of advanced composite carbon fiber reinforced polymer (CFRP) and ultra-high performance concrete reactive powder concrete (RPC) in super-long span cable-stayed bridges , taking a 1 008 m cable-stayed bridge with steel girders and steel cables as an example,a new cable-stayed bridge in the same span with RPC girders and CFRP cables was designed,in which the cable’s cross section was determined by the principle of equivalent cable capacity and the girder’s cross section was determined in virtual of its stiffness, shear capacity and local stability. Based on the methods of finite element analysis,the comparative analysis of these two cable-stayed bridge schemes about static performances,dynamic performances,stability and wind resis-tance behavior were carried out. The results showed that it was feasible to form a highly efficient,durable concrete cable-stayed bridge with RPC girders and CFRP cables and made its applicable span range expand to 1 000 m long around.

  19. Depleted Argon from Underground Sources

    Argon is a strong scintillator and an ideal target for Dark Matter detection; however 39Ar contamination in atmospheric argon from cosmic ray interactions limits the size of liquid argon dark matter detectors due to pile-up. Argon from deep underground is depleted in 39Ar due to the cosmic ray shielding of the earth. In Cortez, Colorado, a CO2 well has been discovered to contain approximately 600 ppm of argon as a contamination in the CO2. We first concentrate the argon locally to 3% in an Ar, N2, and He mixture, from the CO2 through chromatographic gas separation, and then the N2 and He will be removed by continuous distillation to purify the argon. We have collected 26 kg of argon from the CO2 facility and a cryogenic distillation column is under construction at Fermilab to further purify the argon.

  20. Radionuclide behavior at underground environment

    This study of radionuclide behavior at underground environment has been carried out as a part of the study of high-level waste disposal technology development. Therefore, the main objectives of this project are constructing a data-base and producing data for the safety assessment of a high-level radioactive waste, and verification of the objectivity of the assessment through characterization of the geochemical processes and experimental validation of the radionuclide migration. The various results from the this project can be applicable to the preliminary safety and performance assessments of the established disposal concept for a future high-level radioactive waste repository. Providing required data and technical basis for assessment methodologies could be a direct application of the results. In a long-term view, the results can also be utilized as a technical background for the establishment of government policy for high-level radioactive waste disposal