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

Science.gov (United States)

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

Evaluation of DC electric field distribution of PPLP specimen based on the measurement of electrical conductivity in LN2

Science.gov (United States)

Hwang, Jae-Sang; Seong, Jae-Kyu; Shin, Woo-Ju; Lee, Jong-Geon; Cho, Jeon-Wook; Ryoo, Hee-Suk; Lee, Bang-Wook

2013-11-01

High temperature superconducting (HTS) cable has been paid much attention due to its high efficiency and high current transportation capability, and it is also regarded as eco-friendly power cable for the next generation. Especially for DC HTS cable, it has more sustainable and stable properties compared to AC HTS cable due to the absence of AC loss in DC HTS cable. Recently, DC HTS cable has been investigated competitively all over the world, and one of the key components of DC HTS cable to be developed is a cable joint box considering HVDC environment. In order to achieve the optimum insulation design of the joint box, analysis of DC electric field distribution of the joint box is a fundamental process to develop DC HTS cable. Generally, AC electric field distribution depends on relative permittivity of dielectric materials but in case of DC, electrical conductivity of dielectric material is a dominant factor which determines electric field distribution. In this study, in order to evaluate DC electric field characteristics of the joint box for DC HTS cable, polypropylene laminated paper (PPLP) specimen has been prepared and its DC electric field distribution was analyzed based on the measurement of electrical conductivity of PPLP in liquid nitrogen (LN2). Electrical conductivity of PPLP in LN2 has not been reported yet but it should be measured for DC electric field analysis. The experimental works for measuring electrical conductivity of PPLP in LN2 were presented in this paper. Based on the experimental works, DC electric field distribution of PPLP specimen was fully analyzed considering the steady state and the transient state of DC. Consequently, it was possible to determine the electric field distribution characteristics considering different DC applying stages including DC switching on, DC switching off and polarity reversal conditions.

Experimental and analytical study of the DC breakdown characteristics of polypropylene laminated paper with a butt gap condition considering the insulation design of superconducting cable

Science.gov (United States)

Seo, In-jin; Choi, Won; Seong, Jae-gyu; Lee, Bang-wook; Koo, Ja-yoon

2014-08-01

It has been reported that the insulation design under DC stress is considered as one of the critical factors in determining the performance of high-voltage direct current (HVDC) superconducting cable. Therefore, it is fundamentally necessary to investigate the DC breakdown characteristics of the composite insulation system consisting of liquid nitrogen (LN2)/polypropylene-laminated-paper (PPLP). In particular, the insulation characteristics under DC polarity reversal condition should be verified to understand the polarity effect of the DC voltage considering the unexpected incidents taking place at line-commutated-converters (LCC) under service at a DC power grid. In this study, to examine the variation of DC electric field strength, the step voltage and polarity reversal breakdown tests are performed under DC stress. Also, we investigate the electric field distributions in a butt gap of the LN2/PPLP condition considering the DC polarity reversal by using simulation software.

Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges.

Science.gov (United States)

Ahmad, Javaid; Cheng, Shaohong; Ghrib, Faouzi

2015-01-01

Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control.

Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges

Directory of Open Access Journals (Sweden)

Javaid Ahmad

2015-01-01

Full Text Available Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control.

Evaluation of DC electric field distribution of PPLP specimen based on the measurement of electrical conductivity in LN2

International Nuclear Information System (INIS)

Hwang, Jae-Sang; Seong, Jae-Kyu; Shin, Woo-Ju; Lee, Jong-Geon; Cho, Jeon-Wook; Ryoo, Hee-Suk; Lee, Bang-Wook

2013-01-01

Highlights: •The electrical conductivity of PPLP in LN 2 was successfully measured. •Based on the measured value of PPLP, DC field analysis was performed. •The electric field distribution was altered according to the DC applying stages. •The maximum electric field was observed during polarity reversal situation. •DC field analysis is important to determine the optimum design of DC HTS devices. -- Abstract: High temperature superconducting (HTS) cable has been paid much attention due to its high efficiency and high current transportation capability, and it is also regarded as eco-friendly power cable for the next generation. Especially for DC HTS cable, it has more sustainable and stable properties compared to AC HTS cable due to the absence of AC loss in DC HTS cable. Recently, DC HTS cable has been investigated competitively all over the world, and one of the key components of DC HTS cable to be developed is a cable joint box considering HVDC environment. In order to achieve the optimum insulation design of the joint box, analysis of DC electric field distribution of the joint box is a fundamental process to develop DC HTS cable. Generally, AC electric field distribution depends on relative permittivity of dielectric materials but in case of DC, electrical conductivity of dielectric material is a dominant factor which determines electric field distribution. In this study, in order to evaluate DC electric field characteristics of the joint box for DC HTS cable, polypropylene laminated paper (PPLP) specimen has been prepared and its DC electric field distribution was analyzed based on the measurement of electrical conductivity of PPLP in liquid nitrogen (LN 2 ). Electrical conductivity of PPLP in LN 2 has not been reported yet but it should be measured for DC electric field analysis. The experimental works for measuring electrical conductivity of PPLP in LN 2 were presented in this paper. Based on the experimental works, DC electric field distribution of

Evaluation of DC electric field distribution of PPLP specimen based on the measurement of electrical conductivity in LN{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Hwang, Jae-Sang; Seong, Jae-Kyu; Shin, Woo-Ju; Lee, Jong-Geon [Hanyang University, 408-2, 4th Engineering Bldg, Sa 3-dong, Sangrok-gu, Ansan 426-791 (Korea, Republic of); Cho, Jeon-Wook; Ryoo, Hee-Suk [Korea Electrotechnology Research Institute, Changwon, Gyungnam 641-120 (Korea, Republic of); Lee, Bang-Wook, E-mail: bangwook@hanyang.ac.kr [Hanyang University, 408-2, 4th Engineering Bldg, Sa 3-dong, Sangrok-gu, Ansan 426-791 (Korea, Republic of)

2013-11-15

Highlights: •The electrical conductivity of PPLP in LN{sub 2} was successfully measured. •Based on the measured value of PPLP, DC field analysis was performed. •The electric field distribution was altered according to the DC applying stages. •The maximum electric field was observed during polarity reversal situation. •DC field analysis is important to determine the optimum design of DC HTS devices. -- Abstract: High temperature superconducting (HTS) cable has been paid much attention due to its high efficiency and high current transportation capability, and it is also regarded as eco-friendly power cable for the next generation. Especially for DC HTS cable, it has more sustainable and stable properties compared to AC HTS cable due to the absence of AC loss in DC HTS cable. Recently, DC HTS cable has been investigated competitively all over the world, and one of the key components of DC HTS cable to be developed is a cable joint box considering HVDC environment. In order to achieve the optimum insulation design of the joint box, analysis of DC electric field distribution of the joint box is a fundamental process to develop DC HTS cable. Generally, AC electric field distribution depends on relative permittivity of dielectric materials but in case of DC, electrical conductivity of dielectric material is a dominant factor which determines electric field distribution. In this study, in order to evaluate DC electric field characteristics of the joint box for DC HTS cable, polypropylene laminated paper (PPLP) specimen has been prepared and its DC electric field distribution was analyzed based on the measurement of electrical conductivity of PPLP in liquid nitrogen (LN{sub 2}). Electrical conductivity of PPLP in LN{sub 2} has not been reported yet but it should be measured for DC electric field analysis. The experimental works for measuring electrical conductivity of PPLP in LN{sub 2} were presented in this paper. Based on the experimental works, DC electric

Costly cables; Lange Leitung

Energy Technology Data Exchange (ETDEWEB)

Hautmann, Daniel

2012-08-15

Connection of offshore wind turbines to the onshore power supply grid requires costly cables for HV DC power transmission. The technology is mature enough to enable low-loss power transmission, but construction times may last several years.

Problems with conductors and dielectrics for cryogenic cables

Energy Technology Data Exchange (ETDEWEB)

Bogner, G; Penczynski, P [Siemens A.G., Erlangen (F.R. Germany). Abt. Reaktortechnik

1976-06-01

The most important problems which need to be solved if superconducting power cables are to be used on a large scale are connected with the superconducting cable materials and the dielectrics used for insulation. Research work on superconducting materials for ac and dc cables is briefly reviewed together with stabilization problems for these materials. Three types of insulation are considered - vacuum, subcooled or supercritical helium, and foil wound insulation. The merits and problems encountered in each case are discussed.

Impact of corrosion on the reliability of low voltage cables with aluminium conductors

NARCIS (Netherlands)

van Deursen, A.; Kruizinga, B.; Wouters, P.A.A.F.; Steennis, E.F.

2017-01-01

Aluminium is widely used as conductor material for power cables, but corrosion taking place under specific circumstances can have impact on its reliability. Aluminium corrosion under the influence of an alternating current was studied experimentally. Submerged cable segments with inflicted damage

Polyethylene as a possible hvdc cable insulant

Energy Technology Data Exchange (ETDEWEB)

Hawley, W.G.; Body, R.S.; Mason, J.H.

1966-10-01

Many cable authorities have expressed the view that polyethylene would be attractive for this application. The dc conductivity of polyethylene is lower than that of impregnated paper, and varies less with temperature and stress. Polyethylene also has higher thermal conductivity and is resistant to moisture and electrochemical deterioration. Furthermore, processing polyethylene cables should ultimately involve lower capital and manufacturing costs. However, polyethylene has a lower limiting short circuit temperature unless it is cross linked.

Kingsnorth-London dc transmission link

Energy Technology Data Exchange (ETDEWEB)

1966-03-11

The hvdc transmission link between one of the 500 MW generators at Kingsnorth Power Station and two receiving stations in London will use a three-wire dc cable system rated to carry 1200 A at +- 266 kV. This 51-mile system will be the first dc link in the world to be used as an integral part of a complex interconnected ac network.

Conducted EMI Prediction and Mitigation Strategy Based on Transfer Function for a High-Low Voltage DC-DC Converter in Electric Vehicle

Directory of Open Access Journals (Sweden)

Li Zhai

2018-04-01

Full Text Available The high dv/dt and di/dt outputs from power devices in a high-low voltage DC-DC converter on electric vehicles (EVs can always introduce the unwanted conducted electromagnetic interference (EMI emissions. A conducted EMI prediction and mitigation strategy that is based on transfer function for the high-low voltage DC-DC converter in EVs are proposed. A complete test for the DC-DC converter is conducted to obtain the conducted EMI from DC power cables in the frequency band of 150 kHz-108 MHz. The equivalent circuit with high-frequency parasitic parameters of the DC-DC converter is built`1 based on the measurement results to acquire the characteristics of the conducted EMI of the DC power cables. The common mode (CM and differential mode (DM propagation coupling paths are determined, and the corresponding transfer functions of the DM interference and CM interference are established. The simulation results of the conducted EMI can be obtained by software Matlab and Computer Simulation Technology (CST. By analyzing the transfer functions and the simulation results, the dominated interference is the CM interference, which is the main factor of the conducted EMI. A mitigation strategy for the design of the CM interference filter based on the dominated CM interference is proposed. Finally, the mitigation strategy of the conducted EMI is verified by performing the conducted voltage experiment. From the experiment results, the conducted voltage of the DC power cables is decreased, respectively, by 58 dBμV, 55 dBμV, 65 dBμV, 53 dBμV, and 54 dBμV at frequency 200 kHz, 400 kHz, 600 kHz, 1.4 MHz, and 50 MHz. The conduced voltage in the frequency band of 150 kHz–108 MHz can be mitigated by adding the CM interference filters, and the values are lower than the limit level-3 of CISPR25 standard (GB/T 18655-2010.

Drilling history core hole DC-4

International Nuclear Information System (INIS)

1978-12-01

Core hole DC-4 was completed at a depth of 3998 feet in December, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Sicsson, Inc. furnished the engineering, daily supervision of the cable tool and core drilling activities, and geological core logging for DC-4. Core hole DC-4 is located on the Hanford Site about 3 miles east of the Yakima Barricade and approximately 103 feet southwest of rotary hole DC-5, which was completed to 3990 feet in February, 1978. Hanford Site coordinates reported for hole DC-4 are north 49,385.62 feet and west 85,207.63 feet, and Washington State coordinates are north 454,468.73 feet and east 2,209,990.87 feet. No elevation survey is available for hole DC-4, but it is approximately 745 feet above mean sea level based upon the survey of hole DC-5, which has a reported elevation of 745.16 feet on the top of the 3-inch flange. The purpose of core hole DC-4 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing, cross-hole seismic shear, and pressure wave velocity studies with rotary hole DC-5. Hole DC-4 was drilled through the overburden into basalt bedrock by cable tool methods (0-623 feet) and continuously cored through the final interval (623 to 3998 feet).Core recovery was 95.8 percent of the total footage cored

Tests of industrial ethylene-propylene rubber high voltage cable for cryogenic use

CERN Document Server

Balhan, B; Goddard, B; Muratori, G; Otwinowski, S; Rieubland, Jean Michel; Wang, H; CERN. Geneva. SPS and LEP Division

1999-01-01

At the beginning of 1999 UCLA has received a prototype High Voltage Cryogenic Cable supplied fee of charge by Pirelli. The cable is intended for more than ten years of service at 100 kV D.C. and liquid argon temperature. Thecable uses an all welded construction, whichi is axially tight and free of ionizable voids. The cable was submitted to a number of mechanical and electrical tests as described below.

Conventional cable testing methods: strengths, weaknesses and possibilities

International Nuclear Information System (INIS)

Reynolds, P.H.

1988-01-01

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

Development of a single-phase 30 m HTS power cable

Science.gov (United States)

Cho, Jeonwook; Bae, Joon-Han; Kim, Hae-Jong; Sim, Ki-Deok; Kim, Seokho; Jang, Hyun-Man; Lee, Chang-Young; Kim, Dong-Wook

2006-05-01

HTS power transmission cables appear to be the replacement and retrofitting of underground cables in urban areas and HTS power transmission cable offers a number of technical and economic merits compared to the normal conductor cable system. A 30 m long, single-phase 22.9 kV class HTS power transmission cable system has been developed by Korea Electrotechnology Research Institute (KERI), LS Cable Ltd., and Korea Institute of Machinery and Materials (KIMM), which is one of the 21st century frontier project in Korea since 2001. The HTS power cable has been developed, cooled down and tested to obtain realistic thermal and electrical data on HTS power cable system. The evaluation results clarified such good performance of HTS cable that DC critical current of the HTS cable was 3.6 kA and AC loss was 0.98 W/m at 1260 Arms and shield current was 1000 Arms. These results proved the basic properties for 22.9 kV HTS power cable. As a next step, we have been developing a 30 m, three-phase 22.9 kV, 50 MV A HTS power cable system and long term evaluation is in progress now.

Impact Coefficient Analysis of Long-Span Railway Cable-Stayed Bridge Based on Coupled Vehicle-Bridge Vibration

Directory of Open Access Journals (Sweden)

Yongle Li

2015-01-01

Full Text Available Compared with medium and small span bridges, very limited attention has been paid on the research of the impact coefficient of long-span railway bridges. To estimate the impact effects of long-span railway bridges subjected to moving vehicles, a real long-span railway cable-stayed bridge is regarded as the research object in this study, and a coupled model of vehicle-bridge system is established. The track irregularities are taken as the system excitation and the dynamic responses of the vehicle-bridge system are calculated. The impact effects on main girder, stayed cable, bearings, and bridge tower are discussed at various vehicle speeds. The results show that different components of the long-span railway cable-stayed bridge have different impact coefficients. Even for each part, the impact coefficient is also different at different local positions. It reveals that the impact coefficients in the actual situation may have significant differences with the related code clauses in the present design codes.

Improvement of a high current DC power supply system for testing the large scaled superconducting cables and magnets

International Nuclear Information System (INIS)

Yamada, Shuichi; Chikaraishi, Hirotaka; Tanahashi, Shugo

1993-11-01

A dc 75 kA power supply system was constructed to test the superconducting (SC) R and D cables and magnets for the Large Helical Device. It consists of three 25 kA unit banks. A unit bank has two double-star-rectifier connections with the inter-phase reactors. A digital feedback control method is applied to the automatic current regulation (ACR) in each unit bank. For shortening the dead time of the feedback process, a new algorithm of a digital phase controller for the ACR is investigated. A Bode diagram of the feedback process is directly measured. It is confirmed that the dead time of the feedback process is reduced to one sixth, and that the feedback gain of PID compensation is improved by a factor of two from the original method. (author)

Studies for Characterisation of Electrical Properties of DC Collection System in Offshore Wind Farms

DEFF Research Database (Denmark)

Chen, Yu-Hsing; Dincan, Catalin Gabriel; Olsen, Rolant Joannesarson

2016-01-01

Offshore HVDC-connected wind farms where the wind plant power collection network becomes DC, rather than AC, offer reduced electrical losses, lower equipment ratings potentially leading to lower bill-of-material cost, and undiminished functionality. However, no standards exist for an offshore...... medium-voltage DC power collection cable-based system, routing power from MVDC wind turbines all the way to the HVDC export cable. To progress, it is therefore important to establish some common reference for the design and performance of the components needed in an MVDC collection network. Any suggested...... of the MVDC power collection, regardless of choice of turbine converter circuit, MVDC cable configuration, use of DC circuit breakers, substation converter circuit, control and protection. The paper presents the necessary list of studies, and includes examples of simulation results for an exemplary MVDC wind...

Tests on conducted electrical noise on a storage ring dc-dc converter cabinet

International Nuclear Information System (INIS)

Carwardine, J.J.

1994-01-01

Electrical noise is produced by switching transients in the power supply converters which excite resonances formed by stray capacitance and cable inductance. This noise is present not only on the load cables, but also on ground cables of the magnet and of the converter cabinet. Since there will eventually be a large number of cabinets running at one time, tests were carried out to characterize the noise and to investigate possible techniques for reducing the levels. The tests were carried out on the test girder and converter cabinet set up in 412 area. There were four magnets installed on the girder -- two 0.5m quadrupoles, a 0.8m quadrupole, and a sextupole. These tests were carried out on one of the 0.5m quadrupoles. It should be noted that with this setup, the raw dc power was supplied at around 70V. In the final configuration, a 0.5m quad will be fed from a 40V raw supply. Consequently, the switching transients observed during the tests are likely to be higher than will occur in reality. Noise currents contain two main components: a low frequency component at around 50kHz, and a higher frequency component at around lMHz. It is the latter component which is of primary concern. Currents measured on the dc load cables typically were around one ampere, while currents into the building ground system were only a few tens of milliamps. Several methods were used to try reducing the noise currents, but only the addition of a series impedance was successful -- other methods either had no effect or increased the ground currents

A novel powering scheme based on DC-DC conversion for the luminosity upgrades of the CMS tracking system at CERN

International Nuclear Information System (INIS)

Sammet, Jan

2014-01-01

The instantaneous luminosity of the LHC is expected to reach 2 x 10 34 s -1 cm -2 and 5 x 10 34 s -1 cm -2 around the years 2019 and 2024, respectively. After the second upgrade the LHC will be referred to as the High Luminosity LHC (HL-LHC). In order to benefit from the higher luminosities, CMS foresees to upgrade its pixel detector during an extended winter shutdown of the LHC at the end of 2016 and the beginning of 2017. During a long shutdown of the LHC over the years 2022 and 2023, it is foreseen to install a completely new tracking system in CMS. Both upgrades are expected to result in the need to provide more electric current to the detector. However, power losses in cables already contribute 50% to the power consumption of the present tracker and rise with the current squared. Since no more space is available for cables, and thicker cables within the tracking volume spoil the material budget of the detector, new powering schemes are considered mandatory. CMS foresees the use of radiation tolerant DC-DC converters on the front-end to reduce power losses on cables. This thesis describes the new powering scheme of the CMS pixel detector and discusses the options with respect to a new strip tracker. A radiation and magnetic field tolerant DC-DC converter prototype, the PIXV8A, is introduced and the research that led to its development is summarised. The PIXV8A has been developed for the application in the pixel upgrade and is also a first approach for a DC-DC converter for the later upgrade of the CMS tracking system. The PIXV8A makes use of the AMIS4 chip, which has been proven to stay operational for total ionising doses of up to 1 MGy and fluences of up to 10 15 n eq /cm 2 . With an input voltage of 10 V, the PIXV8A converter provides an efficiency of about 80% for output voltages of 2.5 V and 3.0 V. Within this thesis the robustness of the novel powering scheme and the qualification of the PIXV8A are demonstrated in several tests, including system test

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

Directory of Open Access Journals (Sweden)

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.

Southwire's High Temperature Superconducting Cable Development - Summary Report

International Nuclear Information System (INIS)

Sinha, Uday; Lindsay, David

2005-01-01

at 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

Environmental assessment of submarine power cables

Energy Technology Data Exchange (ETDEWEB)

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

Environmental assessment of submarine power cables

International Nuclear Information System (INIS)

Isus, Daniel; Martinez, Juan D.; Arteche, Amaya; Del Rio, Carmen; Madina, Virginia

2011-03-01

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

Power applications for superconducting cables in Denmark

DEFF Research Database (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...... 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...... can be combined with other new technologies such as HVDC light transmission using isolated gate bipolar transistors (IGBTs). The network needed in a system with a substantial wind power generation has to be very strong in order to handle energy fluctuations. Such a network will be possible...

Potential Impact of Submarine Power Cables on Crab Harvest

Science.gov (United States)

Bull, A. S.; Nishimoto, M.

2016-02-01

Offshore renewable energy installations convert wave or wind energy to electricity and transfer the power to shore through transmission cables laid on or buried beneath the seafloor. West coast commercial fishermen, who harvest the highly prized Dungeness crab (Metacarcinus magister) and the rock crab (Cancer spp.), are concerned that the interface of crabs and electromagnetic fields (EMF) from these cables will present an electrified fence on the seafloor that their target resource will not cross. Combined with the assistance of professional fishermen, submarine transmission cables that electrify island communities and offshore oil platforms in the eastern Pacific provide an opportunity to test the harvest of crab species across power transmission cables. In situ field techniques give commercial crab species a choice to decide if they will cross fully energized, EMF emitting, power transmission cables, in response to baited traps. Each independent trial is either one of two possible responses: the crab crosses the cable to enter a trap (1) or the crab does not cross the cable to enter a trap (0). Conditions vary among sample units by the following categorical, fixed factors (i.e., covariates) of cable structure (buried or unburied); direction of cable from crab position (west or east, north or south); time and season. A generalized linear model is fit to the data to determine whether any of these factors affect the probability of crabs crossing an energized cable to enter baited traps. Additionally, the experimental design, aside from the number of runs (set of sample trials) and the dates of the runs, is the same in the Santa Barbara Channel for rock crab and Puget Sound for Dungeness crab, and allows us to compare the capture rates of the two species in the two areas. We present preliminary results from field testing in 2015.

Nonlinear Analysis of Cable Vibration of a Multispan Cable-Stayed Bridge under Transverse Excitation

Directory of Open Access Journals (Sweden)

Kun Lin

2014-01-01

Full Text Available The nonlinear vibrations of cable in a multispan cable-stayed bridge subjected to transverse excitation are investigated. The MECS (multielements cable system model, where multielements per cable stay are used, is built up and used to analyze the model properties of the multispan cable-stayed bridges. Then, a simplified two-degrees-of-freedom (2-DOFs model, where the tower or the deck is reduced to a beam, is proposed to analyze the nonlinear dynamic behaviors of the beam and cable. The results of MECS model analysis show that the main tower in the multispan cable-stayed bridge is prone to the transverse vibration, and the local vibration of cables only has a little impact on the frequency values of the global modes. The results of simplified model analysis show that the energy can be transformed between the modes of the beam and cable when the nature frequencies of them are very close. On the other hand, with the transverse excitation changing, the cable can exhibit richer quasi-periodic or chaotic motions due to the nonlinear terms caused by the coupled mode between the beam and cable.

Critical Current and Stability of MgB$_2$ Twisted-Pair DC Cable Assembly Cooled by Helium Gas

CERN Document Server

AUTHOR|(CDS)2069632; Ballarino, Amalia; Yang, Yifeng; Young, Edward Andrew; Bailey, Wendell; Beduz, Carlo

2013-01-01

Long length superconducting cables/bus-bars cooled by cryogenic gases such as helium operating over a wider temperature range are a challenging but exciting technical development prospects, with applications ranging from super-grid transmission to future accelerator systems. With limited existing knowledge and previous experiences, the cryogenic stability and quench protection of such cables are crucial research areas because the heat transfer is reduced and temperature gradient increased compared to liquid cryogen cooled cables. V-I measurements on gas-cooled cables over a significant length are an essential step towards a fully cryogenic stabilized cable with adequate quench protection. Prototype twisted-pair cables using high-temperature superconductor and MgB2 tapes have been under development at CERN within the FP7 EuCARD project. Experimental studies have been carried out on a 5-m-long multiple MgB$_2$ cable assembly at different temperatures between 20 and 30 K. The subcables of the assembly showed sim...

Design and construction of a high temperature superconducting power cable cryostat for use in railway system applications

International Nuclear Information System (INIS)

Tomita, M; Muralidhar, M; Suzuki, K; Fukumoto, Y; Ishihara, A; Akasaka, T; Kobayashi, Y

2013-01-01

The primary objective of the current effort was to design and test a cryostat using a prototype five-meter long high temperature Bi 2 Sr 2 Ca 2 Cu 3 O y (Bi-2223) superconducting dc power cable for railway systems. To satisfy the safety regulations of the Govt of Japan a mill sheet covered by super-insulation was used inside the walls of the cryostat. The thicknesses of various walls in the cryostat were obtained from a numerical analysis. A non-destructive inspection was utilized to find leaks under vacuum or pressure. The cryostat target temperature range was around 50 K, which is well below liquid nitrogen temperature, the operating temperature of the superconducting cable. The qualification testing was carried out from 77 down to 66 K. When using only the inner sheet wire, the maximum current at 77.3 K was 10 kA. The critical current (I c ) value increased with decreasing temperature and reached 11.79 kA at 73.7 K. This is the largest dc current reported in a Bi 2 Sr 2 Ca 2 Cu 3 O y or YBa 2 Cu 3 O y (Y-123) superconducting prototype cable so far. These results verify that the developed DC superconducting cable is reliable and fulfils all the requirements necessary for successful use in various power applications including railway systems. The key issues for the design of a reliable cryogenic system for superconducting power cables for railway systems are discussed. (paper)

Mass impregnation plant speeds high voltage cable production

Energy Technology Data Exchange (ETDEWEB)

1965-05-07

A mass impregnation and continuous sheath extrusion plant that will eliminate the long period of vacuum treatment usually required for high voltage oil-filled cables is among the latest techniques included in the new factory at Pirelli General's Eastleigh works. The new factory is said to be the first in Europe designed solely for the manufacture of the full range of oil-filled cables. Possible future increases of system voltages to about 750-kV ac or 1000-kV dc have been taken into account in the design of the works, so that only a small amount of modification and new plant will be involved.

Simulation of the cabling process for Rutherford cables: An advanced finite element model

Science.gov (United States)

Cabanes, J.; Garlasche, M.; Bordini, B.; Dallocchio, A.

2016-12-01

In all existing large particle accelerators (Tevatron, HERA, RHIC, LHC) the main superconducting magnets are based on Rutherford cables, which are characterized by having: strands fully transposed with respect to the magnetic field, a significant compaction that assures a large engineering critical current density and a geometry that allows efficient winding of the coils. The Nb3Sn magnets developed in the framework of the HL-LHC project for improving the luminosity of the Large Hadron Collider (LHC) are also based on Rutherford cables. Due to the characteristics of Nb3Sn wires, the cabling process has become a crucial step in the magnet manufacturing. During cabling the wires experience large plastic deformations that strongly modify the geometrical dimensions of the sub-elements constituting the superconducting strand. These deformations are particularly severe on the cable edges and can result in a significant reduction of the cable critical current as well as of the Residual Resistivity Ratio (RRR) of the stabilizing copper. In order to understand the main parameters that rule the cabling process and their impact on the cable performance, CERN has developed a 3D Finite Element (FE) model based on the LS-Dyna® software that simulates the whole cabling process. In the paper the model is presented together with a comparison between experimental and numerical results for a copper cable produced at CERN.

Ocean Thermal Conversion (OTEC) Project Bottom Cable Protection Study: Environmental Characteristics and Hazards Analysis,

Science.gov (United States)

1981-10-01

Chesaneake Division, Naval Facilities Engineering Command, Washington, DC) 34. "Strait of Belle Isle Crossing HVDC Transmission - Submarine Cable...phenomena; such as wind storm generated wave action, bottom currents, bottom mudslides, or seismic activity; as well as human activity, such as...engaging a cable. Ship anchors are used to develop holding power on the seafloor for mooring a floating body permanently or temporary on site. The major

Total Magnetic Field Signatures over Submarine HVDC Power Cables

Science.gov (United States)

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.

ELECTROMAGNETIC COMPATIBILITY OF A DC POWER DISTRIBUTION SYSTEM FOR THE ATLAS LIQUID ARGON CALORIMETER COMPATIBILIDAD ELECTROMAGNÉTICA EN EL SISTEMA DE DISTRIBUCIÓN DE CORRIENTE CONTINUA PARA EL CALORÍMETRO DE ARGÓN LÍQUIDO EN ATLAS

Directory of Open Access Journals (Sweden)

George Blanchot

2008-06-01

Full Text Available The front-end electronics of the ATLAS Liquid Argon Calorimeter is powered by DC/DC converters nearby the front-end crates. They are fed by AC/DC converters located in a remote control room through long power cables. The stability of the power distribution scheme is compromised by the impedance of the long interconnection cable, and proper matching of the converters dynamic impedances is required. Also, the long power cable fed by a powerful AC/DC converter is a source of electromagnetic interferences in the experimental area. The optimal grounding and shielding configuration to minimize these EMI is discussed.El Calorímetro de Argón Líquido en ATLAS es alimentado por convertidores DC/DC localizados cerca de sus compartimientos. Ellos son alimentados por convertidores AC/DC localizados en una sala de control lejana conectados mediante cables largos de poder. La estabilidad del sistema de distribución es sensible a la impedancia del cable largo de interconexión y son requeridos los convertidores apropiados para estabilizar la dinámica de la impedancia. También, el cable largo alimentado por el convertidor AC/DC es una fuente de interferencia electromagnética en el área experimental. En este trabajo se analiza La óptima configuración de aterrizamiento y blindaje para minimizar los efectos de EMI.

Assessing potential impacts of energized submarine power cables on crab harvests

Science.gov (United States)

Love, Milton S.; Nishimoto, Mary M.; Clark, Scott; McCrea, Merit; Bull, Ann Scarborough

2017-12-01

Offshore renewable energy facilities transmit electricity to shore through submarine power cables. Electromagnetic field emissions (EMFs) are generated from the transmission of electricity through these cables, such as the AC inter-array (between unit) and AC export (to shore) cables often used in offshore energy production. The EMF has both an electric component and a magnetic component. While sheathing can block the direct electric field, the magnetic field is not blocked. A concern raised by fishermen on the Pacific Coast of North America is that commercially important Dungeness crab (Metacarcinus magister Dana, 1852)) might not cross over an energized submarine power cable to enter a baited crab trap, thus potentially reducing their catch. The presence of operating energized cables off southern California and in Puget Sound (cables that are comparable to those within the arrays of existing offshore wind energy devices) allowed us to conduct experiments on how energized power cables might affect the harvesting of both M. magister and another commercially important crab species, Cancer productus Randall, 1839. In this study we tested the questions: 1) Is the catchability of crabs reduced if these animals must traverse an energized power cable to enter a trap and 2) if crabs preferentially do not cross an energized cable, is it the cable structure or the EMF emitted from that cable that deters crabs from crossing? In field experiments off southern California and in Puget Sound, crabs were given a choice of walking over an energized power cable to a baited trap or walking directly away from that cable to a second baited trap. Based on our research we found no evidence that the EMF emitted by energized submarine power cables influenced the catchability of these two species of commercially important crabs. In addition, there was no difference in the crabs' responses to lightly buried versus unburied cables. We did observe that, regardless of the position of the cable

Research on resistance characteristics of YBCO tape under short-time DC large current impact

Science.gov (United States)

Zhang, Zhifeng; Yang, Jiabin; Qiu, Qingquan; Zhang, Guomin; Lin, Liangzhen

2017-06-01

Research of the resistance characteristics of YBCO tape under short-time DC large current impact is the foundation of the developing DC superconducting fault current limiter (SFCL) for voltage source converter-based high voltage direct current system (VSC-HVDC), which is one of the valid approaches to solve the problems of renewable energy integration. SFCL can limit DC short-circuit and enhance the interrupting capabilities of DC circuit breakers. In this paper, under short-time DC large current impacts, the resistance features of naked tape of YBCO tape are studied to find the resistance - temperature change rule and the maximum impact current. The influence of insulation for the resistance - temperature characteristics of YBCO tape is studied by comparison tests with naked tape and insulating tape in 77 K. The influence of operating temperature on the tape is also studied under subcooled liquid nitrogen condition. For the current impact security of YBCO tape, the critical current degradation and top temperature are analyzed and worked as judgment standards. The testing results is helpful for in developing SFCL in VSC-HVDC.

An integrated low-voltage rated HTS DC power system with multifunctions to suit smart grids

Energy Technology Data Exchange (ETDEWEB)

Jin, Jian Xun, E-mail: jxjin@uestc.edu.cn [Center of Applied Superconductivity, School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Center of Applied Superconductivity and Electrical Engineering, School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu 611731 (China); Chen, Xiao Yuan [School of Engineering, Sichuan Normal University, Chengdu 610101 (China); Qu, Ronghai; Fang, Hai Yang [School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Xin, Ying [Center of Applied Superconductivity, School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China)

2015-03-15

Highlights: • A novel LVDC HTS power transmission network is presented. • An integrated power system is achieved by using HTS DC cable and SMES. • DC superconducting cable is verified to achieve self-acting fault current limitation. • SMES is verified to achieve fast-response buffering effect under a power fluctuation. • SMES is verified to achieve favorable load voltage protection effect under a fault. - Abstract: A low-voltage rated DC power transmission network integrated with superconducting cables (SCs) and superconducting magnetic energy storage (SMES) devices has been studied with analytic results presented. In addition to the properties of loss-less and high current transportation capacity, the effectively integrated system is formed with a self-acting fault current limitation feature of the SC and a buffering effect of the SMES to power fluctuations. The results obtained show that the integrated system can achieve high-quality power transmission under common power fluctuation conditions with an advanced self-protection feature under short circuit conditions, which is identified to suit especially the smart grid applications.

Partial discharge testing of in-situ power cable accessories

Energy Technology Data Exchange (ETDEWEB)

Orban, H. E.

2002-07-01

An overview of commercially available diagnostic methods for in-situ power cable accessories is given and relevant field experiences with these diagnostics are described. The discussion includes both PILC and polymeric insulated cables. Two major types of degradation are most frequently involved in cable systems. One is an overall condition caused by chemical aging and /or water treeing. Diagnostics for this type of aging include dissipation factor (loss angle), harmonic analysis, return voltage, isothermal relaxation current, dielectric response, or dc leakage current. The second type of degradation is discrete or incremental; condition assessment utilizes dissipation factor measurements or partial discharge (PD) level measurements. The focus in this paper is on PD diagnostics, especially off-line methods such as the 60 Hz test, the combined AC and VLF diagnostic, and the oscillating wave test system test. Among on-line diagnostics, ultrasonic detection of partial discharge and measurement of partial discharge by installing direct, capacitive or inductive couplers near cable accessories, are described. Overall, partial discharge detection and location in cable accessories is considered inadequate, since interpretation of results is difficult due to the number of variables involved. 28 refs., 1 tab.

Interstrand contact resistances of Bi-2212 Rutherford cables for SMES

International Nuclear Information System (INIS)

Kawagoe, A.; Kawabata, Y.; Sumiyoshi, F.; Nagaya, S.; Hirano, N.

2006-01-01

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

Interstrand contact resistances of Bi-2212 Rutherford cables for SMES

Science.gov (United States)

Kawagoe, A.; Kawabata, Y.; Sumiyoshi, F.; Nagaya, S.; Hirano, N.

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.

Reprint of “Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS”

International Nuclear Information System (INIS)

Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun

2013-01-01

Highlights: ► A model-sized superconducting VSC-HVDC system was designed and fabricated. ► A real-time simulation using Real Time Digital Simulator has been performed. ► The AC loss characteristics of HTS DC power cable caused by harmonics were analyzed. ► The AC loss of the HTS DC power cable will be used as a parameter to design the cable cooling system. -- Abstract: The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail

Reprint of “Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS”

Energy Technology Data Exchange (ETDEWEB)

Dinh, Minh-Chau, E-mail: thanchau7787@gmail.com [Changwon National University, 9 Sarim-Dong, Changwon 641-733 (Korea, Republic of); Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon [Changwon National University, 9 Sarim-Dong, Changwon 641-733 (Korea, Republic of); Yu, In-Keun, E-mail: yuik@changwon.ac.kr [Changwon National University, 9 Sarim-Dong, Changwon 641-733 (Korea, Republic of)

2013-01-15

Highlights: ► A model-sized superconducting VSC-HVDC system was designed and fabricated. ► A real-time simulation using Real Time Digital Simulator has been performed. ► The AC loss characteristics of HTS DC power cable caused by harmonics were analyzed. ► The AC loss of the HTS DC power cable will be used as a parameter to design the cable cooling system. -- Abstract: The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

Hysteresis Control for a DC Connected Synchronous Generator

DEFF Research Database (Denmark)

Rasmussen, Tonny Wederberg; Evangelos, Dimarakis

2009-01-01

Abstract— for offshore wind farms the distance to the coast increases, therefore DC cables will have to be used. For a variable speed wind turbine a rectifier and a synchronous generator with a boost converter is used. As a new suggestion for control the generator speed hysteresis control...

Environmental impacts and resource losses of incinerating misplaced household special wastes (WEEE, batteries, ink cartridges and cables)

DEFF Research Database (Denmark)

Bigum, Marianne Kristine Kjærgaard; Damgaard, Anders; Scheutz, Charlotte

2017-01-01

The contribution of misplaced special waste (sWEEE, lamps, CRT, batteries, ink cartridges and cables) to environmental impacts from incineration of residual household waste was quantified through life cycle assessment (LCA)-modelling. Misplaced special waste was quantified to constitute less than 1...... and batteries. However as shown by sensitivity analysis, lack of good data on the transfer of rare and hazardous metals to the flue gas in the incineration process should receive further investigation before the environmental impacts from misplaced incinerated special waste can fully be concluded upon. Although...... special waste (sWEEE, lamps, CRT, batteries, ink cartridges, and cables)....

Cabling for an SSC silicon tracking system

International Nuclear Information System (INIS)

Ziock, H.; Boissevain, J.; Cooke, B.; Miller, W.

1990-01-01

As part of the Superconducting Super Collider Laboratory (SSCL) funded silicon tracking subsystem R ampersand D program, we examine the problems associated with cabling such a system. Different options for the cabling plant are discussed. A silicon microstrip tracking detector for an SSC experiment is an extremely complex system. The system consists of approximately 10 7 detector channels, each of which requires a communication link with the outside world and connections to the detector bias voltage supply, to a DC power supply for the onboard electronics, and to an adjustable discrimination level. The large number of channels and the short time between beam interactions (16 nanoseconds) dictates the need for high speed and large bandwidth communication channels, and a power distribution system that can handle the high current draw of the electronics including the large AC component due to their switching. At the same time the constraints imposed by the physics measurements require that the cable plant have absolutely minimal mass and radiation length. 4 refs., 2 figs

First tests of twisted-pair HTS 1 kA range cables for use in superconducting links

CERN Document Server

Ballarino, A; Hurte, J; Sitko, M; Willering, G

2011-01-01

The requirement at CERN for 1 kA range High Temperature Superconducting (HTS) cables optimized for long electrical transfer has led to the design and assembly of a novel type of cable that can be made from pre-reacted MgB2, Bi-2223 or YBCO tapes. The cable consists of an assembly of twisted pairs, each of which is made from three superconducting tapes with the required copper stabilizer. The twisted pair cable is designed to transfer a DC current of ± 600 A in helium gas environment. The paper reports on the results of the electrical tests performed on twisted-pair cables of identical structure and made from commercially available MgB2, Bi-2223 and YBCO tapes. The twist pitch of the cables is adapted to match the mechanical properties of the different superconductors. Critical current tests were performed at both liquid helium and liquid nitrogen temperature. The electrical performance of several cables made from different conductors is reported and compared.

AC Voltage Control of DC/DC Converters Based on Modular Multilevel Converters in Multi-Terminal High-Voltage Direct Current Transmission Systems

Directory of Open Access Journals (Sweden)

Rui Li

2016-12-01

Full Text Available The AC voltage control of a DC/DC converter based on the modular multilevel converter (MMC is considered under normal operation and during a local DC fault. By actively setting the AC voltage according to the two DC voltages of the DC/DC converter, the modulation index can be near unity, and the DC voltage is effectively utilized to output higher AC voltage. This significantly decreases submodule (SM capacitance and conduction losses of the DC/DC converter, yielding reduced capital cost, volume, and higher efficiency. Additionally, the AC voltage is limited in the controllable range of both the MMCs in the DC/DC converter; thus, over-modulation and uncontrolled currents are actively avoided. The AC voltage control of the DC/DC converter during local DC faults, i.e., standby operation, is also proposed, where only the MMC connected on the faulty cable is blocked, while the other MMC remains operational with zero AC voltage output. Thus, the capacitor voltages can be regulated at the rated value and the decrease of the SM capacitor voltages after the blocking of the DC/DC converter is avoided. Moreover, the fault can still be isolated as quickly as the conventional approach, where both MMCs are blocked and the DC/DC converter is not exposed to the risk of overcurrent. The proposed AC voltage control strategy is assessed in a three-terminal high-voltage direct current (HVDC system incorporating a DC/DC converter, and the simulation results confirm its feasibility.

Tailored sPP/Silica Nanocomposite for Ecofriendly Insulation of Extruded HVDC Cable

Directory of Open Access Journals (Sweden)

Bin Dang

2015-01-01

Full Text Available Cross-linked polyethylene (XLPE is a thermosetting material that cannot be recycled at the end of its lifetime. This study investigated the potential of syndiotactic polypropylene (sPP/silica as an ecofriendly extruded insulation system for HVDC cables. We investigated the morphology, Fourier transform infrared, and thermal, thermomechanical, and electrical behaviors of sPP modified with 0.5–3% nanosilica. We found that the silica/sPP nanocomposite without cross-linking offered a suitable mechanical modulus at room temperature and sufficient intensity at high temperatures, and adding nanosilica modified by a silane coupling agent to the sPP resulted in significant DC resistivity and space charge improvement. The optimal nanosilica content in the sPP was determined by balancing the mechanical and thermomechanical characteristics and the DC resistivity. The sPP/silica nanocomposite reported here shows great potential as a candidate insulation material for future ecofriendly extruded HVDC cables.

Impacts on the Voltage Profile of DC Distribution Network with DG Access

Science.gov (United States)

Tu, J. J.; Yin, Z. D.

2017-07-01

With the development of electronic, more and more distributed generations (DGs) access into grid and cause the research fever of direct current (DC) distribution network. Considering distributed generation (DG) location and capacity have great impacts on voltage profile, so use IEEE9 and IEEE33 typical circuit as examples, with DGs access in centralized and decentralized mode, to compare voltage profile in alternating and direct current (AC/DC) distribution network. Introducing the voltage change ratio as an evaluation index, so gets the general results on voltage profile of DC distributed network with DG access. Simulation shows that, in the premise of reasonable location and capacity, DC distribution network is more suitable for DG access.

Impact of Slim DC Capacitance on Floating Capacitor H-bridge Motor Drive

DEFF Research Database (Denmark)

Leng, Siyu; Muyeen, S.M.; Al-Durra, Ahmed

2018-01-01

harmonics will be generated in the motor line voltage. This demonstrates the possibility of drastically reducing the dc capacitance of the proposed system. Induction motor as well as H-bridge performance with respect to different dc capacitance values is demonstrated by experiments, which lays......This paper discusses the impact of small dc capacitance in a motor drive using a floating capacitor H-bridge topology. The proposed topology is intended for applications where variable frequency control is not required. Special attention is paid on investigating the second-order dc capacitor...... voltage ripples, whose influence on the induction motor as well as on the motor drive itself is of importance. This issue is addressed in this paper through rigorous mathematical formulations. It is found that by inverting the second-order dc ripple voltage using the conventional SVPWM, no harmful...

Comparative study on life cycle environmental impact assessment of copper and aluminium cables

Science.gov (United States)

Bao, Wei; Lin, Ling; Song, Dan; Guo, Huiting; Chen, Liang; Sun, Liang; Liu, Mei; Chen, Jianhua

2017-11-01

With the rapid development of industrialization and urbanization in China, domestic demands for copper and aluminium resources increase continuously and the output of copper and aluminium minerals rises steadily. The output of copper in China increased from 0.6 million tons (metal quantity) in 2003 to 1.74 million tons (metal quantity) in 2014, and the output of bauxite increased from 21 million tons in 2006 to 59.21 million tons in 2014. In the meantime, the import of copper and aluminium minerals of China is also on a rise. The import of copper concentrate and bauxite increased from 4.94 million tons and 9.68 million tons in 2006 to 10.08 million tons and 70.75 million tons in 2013 respectively. Copper and aluminium resources are widely applied in fields such as construction, electrical and electronics, machinery manufacturing, and transportation, and serve as important material basis for the national economic and social development of China. Cable industry is a typical industry where copper and aluminium resources are widely used. In this paper, a product assessment model is built from the perspective of product life cycle. Based on CNLCD database, differences in environmental impacts of copper and aluminium cables are analyzed from aspects such as resource acquisition, product production, transportation, utilization, and resource recycling. Furthermore, the advantages and disadvantages of products at different stages with different types of environmental impact are analyzed, so as to provide data support for cable industry in terms of product design and production, etc.

Air flow around suspended cables

Directory of Open Access Journals (Sweden)

Gołębiowska Irena

2017-01-01

Full Text Available The impact of wind on construction structures is essential issue in design and operation. In particular, the wind can cause the dengerous vibrations of slender structures with low rigidity, eg. vibrations of cables of suspension and cable-stayed bridges or high voltage transmision lines, thus understanding of wind flow around such constructions is significant. In the paper the results of the analysis of wind flow around the cables for different Reynolds number is presented. The analysed flow meets the Navier-Stokes and continuity equations. The circle and elipse section of the cable is analysed. The discusion of vorticity, drag and lift coefficients and cases due to different angle of wind flow action is presented. The boundary layer and its infuence on total flow is analysed.

Automated Cable Preparation for Robotized Stator Cable Winding

Directory of Open Access Journals (Sweden)

Erik Hultman

2017-04-01

Full Text Available A method for robotized cable winding of the Uppsala University Wave Energy Converter generator stator has previously been presented and validated. The purpose of this study is to present and validate further developments to the method: automated stand-alone equipment for the preparation of the winding cables. The cable preparation consists of three parts: feeding the cable from a drum, forming the cable end and cutting the cable. Forming and cutting the cable was previously done manually and only small cable drums could be handled. Therefore the robot cell needed to be stopped frequently. The new equipment was tested in an experimental robot stator cable winding setup. Through the experiments, the equipment was validated to be able to perform fully automated and robust cable preparation. Suggestions are also given on how to further develop the equipment with regards to performance, robustness and quality. Hence, this work represents another important step towards demonstrating completely automated robotized stator cable winding.

Cable Television and Educational Access: A Reconsideration.

Science.gov (United States)

Thornton, Lee R.; Greene, James C.

1986-01-01

Considers the possible impact of recent federal legislation on educational utilization of cable television. Stresses the importance of educators understanding the law's provisions and acting to initiate relationships with cable companies. Reviews public educational or governmental access provisions. Presents strategies for promoting reciprocity…

Development of a superconducting cable for transmission of high electric power

International Nuclear Information System (INIS)

Moisson, F.; Leroux, J.M.

1971-01-01

The opportunities opened by the use of cryoresistive and superconducting materials in underground transmission systems have led to a cryocable program. A first set of problems associated with the development of cryogenic cables deals with the cable system, i.e., design, safety, terminal equipment including leads, cryogenic equipment, refrigerators, and problems related to overload capability and reliability. A second set concerns the cable itself, i.e., scientific and technological problems associated with the conductor, the electrical insulation, and the thermal exchange between conductor and helium. Useful experience is gained on the design problems and on the technological problems involved in the construction of a cryoconducting cable. A 20-M aluminum cable cooled down to 25 0 K with pressurized helium flow was built and tested with 3500-A dc under 20 Kv; results are presented. On this model the following types of problems were solved. First, mechanical problems concerning cooling of the cable, thermal contraction of the pipes, electrical insulation and conductors, construction of an invariable cable constituted by elementary helically wound conductors were solved. Second, thermal problems of reduction of heat leaks, conception of thermal insulation, and segmentation of vacuum jackets were solved. Third, electrical problems of design of 300 0 to 25 0 K leads were solved; this problem of losses at both ends is, in proportion, more important for the short model than for long cable. Finally, refrigeration problems of helium and nitrogen flows, thermal shields and design of refrigerators (optimal capacity and spacing) were solved

Construction and 1st Experiment of the 500-meter and 1000-meter DC Superconducting Power Cable in Ishikari

Science.gov (United States)

Yamaguchi, S.; Ivanov, Y.; Watanabe, H.; Chikumoto, N.; Koshiduka, H.; Hayashi, K.; Sawamura, T.

Ishikari project constructs two lines. The length of the Line 1 is 500 m, and connects the photovoltaic cell to the internet-data center. The other line is 1 km length, and it is a test facility and called Line 2. The structures of the cable systems are not same to test their performance. The construction was started from 2014 in the field, the Line 1 was completed in May 2015, and it was cooled down and do the current experiment, and warmed up. The Line 2 is almost complete in October 2015. It will be tested in November and December, 2015. In order to reduce the stress of the cable induced by the thermal expansion and contraction, we adopted the way of the helical deformation of the cable. The force of the cable is reduced to 1/3 of an usual cable test. Because the cryogenic pipes are welded in the field and we cannot use the baking of the vacuum chamber of the cryogenic pipe, a new vacuum pumping method was proposed and tested for the cryogenic pipe. Since the straight pipes are used to compose the cryogenic pipe, the pressure drop of the circulation would be 1/100 of the corrugated pipe in the present condition, and it is suitable for longer cable system. The heat leak of the cryogenic pipe is ∼1.4W/m including the cable pipe's and the return pipe's. The heat leak of the current lead is ∼30W/kA in the test bench. Finally the current of 6kA/3 sec and the current of 5kA/15 min were achieved in Line 1. The reduction of heat leak will be a major subject of the longer cable system. The cost of the construction will be almost twice higher than that of the copper and aluminum over-head line with the iron tower in the present Japan. The cost construction of the over-head line is an average value, and depends on the newspaper.

Behaviour of electrical cables under fire conditions

International Nuclear Information System (INIS)

Bertrand, R.; Chaussard, M.; Gonzalez, R.; Lacoue, J.; Mattei, J.M.; Such, J.M.

2002-01-01

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.) [de

dc Arc Fault Effect on Hybrid ac/dc Microgrid

Science.gov (United States)

Fatima, Zahra

The advent of distributed energy resources (DER) and reliability and stability problems of the conventional grid system has given rise to the wide spread deployment of microgrids. Microgrids provide many advantages by incorporating renewable energy sources and increasing the reliability of the grid by isolating from the main grid in case of an outage. AC microgrids have been installed all over the world, but dc microgrids have been gaining interest due to the advantages they provide over ac microgrids. However the entire power network backbone is still ac and dc microgrids require expensive converters to connect to the ac power network. As a result hybrid ac/dc microgrids are gaining more attention as it combines the advantages of both ac and dc microgrids such as direct integration of ac and dc systems with minimum number of conversions which increases the efficiency by reducing energy losses. Although dc electric systems offer many advantages such as no synchronization and no reactive power, successful implementation of dc systems requires appropriate protection strategies. One unique protection challenge brought by the dc systems is dc arc faults. A dc arc fault is generated when there is a gap in the conductor due to insulation degradation and current is used to bridge the gap, resulting in an arc with very high temperature. Such a fault if it goes undetected and is not extinguished can cause damage to the entire system and cause fires. The purpose of the research is to study the effect of the dc arc fault at different locations in the hybrid ac/dc microgrid and provide insight on the reliability of the grid components when it is impacted by arc faults at various locations in the grid. The impact of dc arc fault at different locations on the performance of the PV array, wind generation, and constant power loads (CPL) interfaced with dc/dc converters is studied. MATLAB/Simulink is used to model the hybrid ac/dc microgrid and arc fault.

Analytical Assessment of Environmental Impact for APR1400DC UHS Cooling Tower

Energy Technology Data Exchange (ETDEWEB)

Lee, Jaiho [KHNP-Central Research Institute, Daejeon (Korea, Republic of)

2015-05-15

Hot process water is pumped from the plant process to the cooling towers. Heat is rejected through evaporation of the process water, interacting with ambient air blown upward by fans.. Plumes generated from exit ports of the cooling tower may have adverse effects on the environment, such as deposition of cooling tower drift release, fogging, icing, shadowing, and ground-level temperature and humidity increase. These kinds of environmental impact of the cooling tower are linked closely with the dispersion of the cooling tower plumes. In this respect, predicting the behavior of the plumes has become one of the most important issues in the environmental assessments of the cooling towers. The SACTI (seasonal/annual cooling tower impact) model is an analytical tool to predict the environmental effect of cooling tower, which was developed by Argonne National Laboratory and University of Illinois with support from EPRI (electric power research institute). The initial version of SACTI has been widely used to assess the environmental effect of cooling towers in many industrial fields such as steam power plants and NPPs. Guo et. al. investigated impact of heat rejection and cooling tower height on plume dispersion using the SACTI model, for the purpose of the future construction of inland NPPs. They found that increasing cooling tower height decreases the plume length and height frequencies. Their simulation results showed that the increase in heat rejection increases the plum radius frequency. The APR1400DC is an advanced light water reactor developed for the purpose of NRC-DC (design certification). The cooling towers for APR1400DC UHS consist of two linear mechanical draft cooling towers (LMDCTs). The LMDCT for APR1400DC UHS is conceptually designed because the plant site has not been decided yet. In the present study, the dependency of plume dispersion on the number of cooling towers is investigated using SACTI-2-beta, for predicting annual environmental effect of APR

Tailored sPP/Silica Nano composite for Eco friendly Insulation of Extruded HVDC Cable

International Nuclear Information System (INIS)

Dang, B.; He, J.; Hu, J.; Zhou, Y.

2015-01-01

Cross-linked polyethylene (XLPE) is a thermosetting material that cannot be recycled at the end of its lifetime. This study investigated the potential of syndiotactic polypropylene (sPP)/silica as an eco friendly extruded insulation system for HVDC cables. We investigated the morphology, Fourier transform infrared, and thermal, thermomechanical, and electrical behaviors of sPP modified with 0.5-3% nano silica. We found that the silica/sPP nano composite without cross-linking offered a suitable mechanical modulus at room temperature and sufficient intensity at high temperatures, and adding nano silica modified by a silane coupling agent to the sPP resulted in significant DC resistivity and space charge improvement. The optimal nano silica content in the sPP was determined by balancing the mechanical and thermomechanical characteristics and the DC resistivity. The sPP/silica nano composite reported here shows great potential as a candidate insulation material for future eco friendly extruded HVDC cables.

Numerical analysis of the stability of HTS power cable under fault current considering the gaps in the cable

International Nuclear Information System (INIS)

Fang, J.; Li, H.F.; Zhu, J.H.; Zhou, Z.N.; Li, Y.X.; Shen, Z.; Dong, D.L.; Yu, T.; Li, Z.M.; Qiu, M.

2013-01-01

Highlights: •The equivalent circuit equations and the heat balance equations were established. •The current distributions of the HTS cable under fault current were obtained. •The temperature curves of conductor layers under fault current were obtained. •The effect of the gap liquid nitrogen on the thermal characteristics was studied. -- Abstract: During the operation of a high temperature superconducting power cable in a real grid, the power cable can be impacted inevitably by large fault current. The study on current distribution and thermal characteristics in the cable under fault current is the foundation to analyze its stability. To analyze the operation situation of 110 kV/3 kA class superconducting cable under the fault current of 25 kA rms for 3 s, the equivalent circuit equations and heat balance equations were established. The current distribution curves and the temperature distribution curves were obtained. The liquid nitrogen which exists in the gaps of HTS cable was taken into consideration, the influence of gap liquid nitrogen on the thermal characteristics was investigated. The analysis results can be used to estimate the security and stability of the superconducting cable

Numerical analysis of the stability of HTS power cable under fault current considering the gaps in the cable

Energy Technology Data Exchange (ETDEWEB)

Fang, J., E-mail: fangseer@sina.com [School of Electrical Engineering, Beijing Jiaotong University, Beijing 100044 (China); Li, H.F. [School of Electrical Engineering, Beijing Jiaotong University, Beijing 100044 (China); Zhu, J.H.; Zhou, Z.N. [China Electric Power Research Institute, Beijing 100192 (China); Li, Y.X.; Shen, Z.; Dong, D.L.; Yu, T. [School of Electrical Engineering, Beijing Jiaotong University, Beijing 100044 (China); Li, Z.M.; Qiu, M. [China Electric Power Research Institute, Beijing 100192 (China)

2013-11-15

Highlights: •The equivalent circuit equations and the heat balance equations were established. •The current distributions of the HTS cable under fault current were obtained. •The temperature curves of conductor layers under fault current were obtained. •The effect of the gap liquid nitrogen on the thermal characteristics was studied. -- Abstract: During the operation of a high temperature superconducting power cable in a real grid, the power cable can be impacted inevitably by large fault current. The study on current distribution and thermal characteristics in the cable under fault current is the foundation to analyze its stability. To analyze the operation situation of 110 kV/3 kA class superconducting cable under the fault current of 25 kA{sub rms} for 3 s, the equivalent circuit equations and heat balance equations were established. The current distribution curves and the temperature distribution curves were obtained. The liquid nitrogen which exists in the gaps of HTS cable was taken into consideration, the influence of gap liquid nitrogen on the thermal characteristics was investigated. The analysis results can be used to estimate the security and stability of the superconducting cable.

DC injection into low voltage AC networks

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

This report summarises the results of a study investigating the impact of levels of injected DC current injections on a low voltage AC distribution network systems in order to recommend acceptable limits of DC from microgeneration. Relevant literature is reviewed, and the impact of DC levels in distribution transformers, transformer modelling, and instrumental transformers are discussed. The impact of DC in residual current devices (RCD) and in domestic electricity watt hour meters is examined along with DC enhanced corrosion, corrosion failure, and the measurement of DC current injection. Sources of DC injection outlined include DC from computer power supplies, network faults, geomagnetic phenomena, lighting circuits/dimmers, and embedded generators.

Calculation and measurement of space charge in MV-size xxtruded cables systems under load conditions

NARCIS (Netherlands)

Morshuis, P.H.F.; Bodega, R.; Fabiani, D.; Montanari, G.C.; Dissado, L.A.; Smit, J.J.

2007-01-01

A load current in dc high voltage cables results in a temperature drop across the insulation and hence a radial distribution of the insulation conductivity is found. Direct consequence is an accumulation of space charge in the bulk of the nsulation, that may significantly affect its reliability.

AC losses in superconductors: a multi-scale approach for the design of high current cables

International Nuclear Information System (INIS)

Escamez, Guillaume

2016-01-01

The work reported in this PhD deals with AC losses in superconducting material for large scale applications such as cables or magnets. Numerical models involving FEM or integral methods have been developed to solve the time transient electromagnetic distributions of field and current densities with the peculiarity of the superconducting constitutive E-J equation. Two main conductors have been investigated. First, REBCO superconductors for applications operating at 77 K are studied and a new architecture of conductor (round wires) for 3 kA cables. Secondly, for very high current cables, 3-D simulations on MgB_2 wires are built and solved using FEM modeling. The following chapter introduced new development used for the calculation of AC losses in DC cables with ripples. The thesis ends with the use of the developed numerical model on a practical example in the european BEST-PATHS project: a 10 kA MgB_2 demonstrator [fr

Behaviour of French electrical cables under fire conditions

Energy Technology Data Exchange (ETDEWEB)

Bertrand, R.; Chaussard, M.; Gonzalez, R.; Lacoue, J.; Mattei, J.M.; Such, J.M

2001-12-01

A fire Probabilistic Safety Assessment - called fire PSA - is being carried out by the French Institute of Nuclear Safety and Protection (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 that are a significant risk contributor. The purpose of this communication is to present the electrical cable fire tests carried out by IPSN to identify the failure modes and to determine the cable damage criteria. Moreover, are indicated 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. (authors)

Optical fibers for remote spectrometry of alkali elements in the dc arc

International Nuclear Information System (INIS)

Faires, L.M.; Bieniewski, T.M.; Apel, C.T.; Niemczyk, T.M.

1985-01-01

An optical fiber cable is designed, characterized, and applied to the remote spectrometric analysis of alkali elements as impurities in plutonium by dc arc emission. The analytical performance of the dc arc/optical fiber/polychromator system is tested by the establishment of analytical working curves for sodium, potassium, and rubidium from a set of standards. Accuracy, determined by the use of control samples of known concentration, is found to be 10% or better. The new analytical system provides improvement in both accuracy and efficiency compared to the previously used spectrographic technique

Electrical Tree Initiation and Growth in Silicone Rubber under Combined DC-Pulse Voltage

Directory of Open Access Journals (Sweden)

Tao Han

2018-03-01

Full Text Available Electrical tree is a serious threat to silicone rubber (SIR insulation and can even cause breakdown. Electrical trees under alternating current (AC and direct current (DC voltage have been widely researched. While there are pulses in high-voltage direct current (HVDC cables under operating conditions caused by lightning and operating overvoltage in the power system, little research has been reported about trees under combined DC-pulse voltage. Their inception and growth mechanism is still not clear. In this paper, electrical trees are studied under several types of combined DC-pulse voltage. The initiation and growth process was recorded by a digital microscope system. The experimental results indicate that the inception pulse voltage is different under each voltage type and is influenced by the combined DC. The initial tree has two structures, determined by the pulse polarity. With increased DC prestressing time, tree inception pulse voltage with the same polarity is clearly decreased. Moreover, a special initial bubble tree was observed after the prestressing DC.

Multilink DC Transmission System for Supergrid Future Concepts and Wind Power Integration

DEFF Research Database (Denmark)

Silva, Rodrigo Da; Teodorescu, Remus; Rodriguez, Pedro

2011-01-01

A possible methodology for the power sharing is based on DC voltage droop control at onshore station converters. The aim is to present an evaluation tool for the droop control parameter description in support of DC power sharing. Main limitation for this method regarding sharing factors definition...... and overvoltages are going to be revised. A study case using two different onshore stations are going to be used. Both of them are sized with different power ratings and they have different distances from the offshore converters. This benchmark is suitable as starting point for future prospects of DC supergrids....... Using the concept of virtual impedances, the droop parameters are limited by the boundaries of the DC voltage limits and line characteristics. For the power sharing point of view, mainly the cable resistances are considered. Simulation results using time domain simulation (EMTDC/PSCAD) will reinforce...

Insulating and sheathing materials of electric and optical cables - Common test methods - Part 5-1: Methods specific to filling compounds - Drop-point - Separation of oil - Lower temperature brittleness - Total acid number - Absence of corrosive components - Permittivity at 23 °C - DC resistivity at 23 °C and 100 °C

CERN Document Server

International Electrotechnical Commission. Geneva

2004-01-01

Specifies the test methods for filling compounds of electric cables used with telecommunication equipment. Gives the methods for drop-point, separation of oil, lower temperature brittleness, total acid number, absence of corrosive components, permittivity at 23 °C, d.c. resistivity at 23°C and 100°C.

Cable aging tests

International Nuclear Information System (INIS)

Hubbard, G.

1993-01-01

This paper describes the results from aging, condition monitoring, and loss-of-coolant accident (LOCA) testing of class 1E electrical cables, per NUREG/CR-5772. This test was designed to test the performance of cables which had been aged with simultaneous radiation and thermal exposure. The tested cables included crosslinked polyolefin cables, ethylene propylene rubber cables, and miscellaneous cable types. Cables were exposed to 20, 40, and 60 years equivalent aging, and then exposed to LOCA tests at the end of their qualified life to determine the minimum insulation thickness needed for survival of the test. Failures were found in a large number of the tested cables. As a result the NRC has sent information notices to the industry regarding potential insulation problems. The results have raised the question of whether the artificial aging methods provide adequate testing methods. As a result of this testing the NRC is reviewing the artificial aging procedures, the adequacy of environmental qualification requirements for cable safety, and reexamining data from condition monitoring of installed cables

Line-to-Line Fault Analysis and Location in a VSC-Based Low-Voltage DC Distribution Network

Directory of Open Access Journals (Sweden)

Shi-Min Xue

2018-03-01

Full Text Available A DC cable short-circuit fault is the most severe fault type that occurs in DC distribution networks, having a negative impact on transmission equipment and the stability of system operation. When a short-circuit fault occurs in a DC distribution network based on a voltage source converter (VSC, an in-depth analysis and characterization of the fault is of great significance to establish relay protection, devise fault current limiters and realize fault location. However, research on short-circuit faults in VSC-based low-voltage DC (LVDC systems, which are greatly different from high-voltage DC (HVDC systems, is currently stagnant. The existing research in this area is not conclusive, with further study required to explain findings in HVDC systems that do not fit with simulated results or lack thorough theoretical analyses. In this paper, faults are divided into transient- and steady-state faults, and detailed formulas are provided. A more thorough and practical theoretical analysis with fewer errors can be used to develop protection schemes and short-circuit fault locations based on transient- and steady-state analytic formulas. Compared to the classical methods, the fault analyses in this paper provide more accurate computed results of fault current. Thus, the fault location method can rapidly evaluate the distance between the fault and converter. The analyses of error increase and an improved handshaking method coordinating with the proposed location method are presented.

Cable line engineering

International Nuclear Information System (INIS)

Jang, Hak Sin; Kim, Sin Yeong

1998-02-01

This book is about cable line engineering. It is comprised of nine chapters, which deals with summary of cable communication such as way, process of cable communication and optical communication, Line constant of transmission on primary constant, reflection and crosstalk, communication cable line of types like flat cable, coaxial cable and loaded cable, Install of communication line with types and facility of aerial line, construction method of communication line facility, Measurement of communication line, Carrier communication of summary, PCM communication with Introduction, regeneration relay system sampling and quantization and Electric communication service and general information network with mobile communication technique and satellite communication system.

Effects of EMF Emissions from Cables and Junction Boxes on Marine Species

Energy Technology Data Exchange (ETDEWEB)

Dhanak, Manhar [Florida Atlantic Univ., Boca Raton, FL (United States); Spieler, Richard [Nova Southeastern Univ., Fort Lauderdale, FL (United States); Kilfoyle, Kirk [Nova Southeastern Univ., Fort Lauderdale, FL (United States); Jermain, Robert F. [Nova Southeastern Univ., Fort Lauderdale, FL (United States); Frankenfield, John [Florida Atlantic Univ., Boca Raton, FL (United States); Ravenna, Shirley [Florida Atlantic Univ., Boca Raton, FL (United States); Dibiasio, Christopher [Florida Atlantic Univ., Boca Raton, FL (United States); Coulson, Robert [Florida Atlantic Univ., Boca Raton, FL (United States); Henderson, Ed [Florida Atlantic Univ., Boca Raton, FL (United States); Venezia, William [Naval Surface Warfare Center (NSWC), Carderock Division (United States)

2016-09-29

Studies have shown that diverse aquatic species are electrosensitive. Many fishes, and marine mammals, can either detect, navigate by, or are affected by electromagnetic fields (EMF) with various sensitivities, and their behavior may be impacted by unnatural EMF emissions in the water column. Sharks, rays and skates are known to have the highest sensitivity to electric fields. Electric field emissions in the range 0.5–100 micro volt/m appear to attract them, and emissions over 100 micro volt/m to repulse them. A marine hydrokinetic MHK device will have multiple components and associated multiple submarine cables on the seafloor and running through the water column and would potentially increase the level of EMF emissions to which the marine species at the site may be exposed to. There are therefore concerns amongst stakeholders that EMF emissions associated with MHK devices and their components may act as barriers to species migration, cause disorientation, change community compositions and ecosystems, and that they may attract sharks, leading to a local increase in the risk of shark attacks. However, field data to validate and model potential relationships between observed responses and the EMF emissions in situ are sparse. A program of experimental field surveys were conducted off the coast of South Florida, USA to characterize the electromagnetic field (EMF) emissions in the water column from a submarine cable, and to monitor for responses of local aquatic species. The field surveys were conducted at the South Florida Ocean Measurement Facility (SFOMF) off Fort Lauderdale, which is a cabled offshore in-water navy range. It consists of multiple active submarine power cables and a number of junction boxes, with the capability to transmit AC/DC power at a range of strength and frequencies. The site includes significant marine life activities and community structure, including highly mobile species, such as sharks, stingrays, mammals and turtles. SFOMF therefore

Cables, Sharks and Servers: Technology and the Geography of the Foreign Exchange Market

OpenAIRE

Eichengreen, Barry; Lafarguette, Romain; Mehl, Arnaud

2016-01-01

We analyze the impact of technology on production and trade in services, focusing on the foreign exchange market. We identify exogenous technological changes by the connection of countries to submarine fiber-optic cables used for electronic trading, but which were not laid for purposes related to the foreign exchange market. We estimate the impact of cable connections on the share of offshore foreign exchange transactions. Cable connections between local markets and matching servers in the ma...

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

International Nuclear Information System (INIS)

Anon.

1991-01-01

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

Power and Submarine Cable Systems for the KM3NeT kilometre cube Neutrino Telescope

CERN Document Server

Sedita, M; Hallewell, G

2009-01-01

The KM3NeT EU-funded consortium, pursuing a cubic kilometre scale neutrino telescope in the Mediterranean Sea, is developing technical solutions for the construction of this challenging project, to be realized several kilometres below the sea level. In this framework a proposed DC/DC power system has been designed, maximizing reliability and minimizing difficulties and expensive underwater activities. The power conversion, delivery, transmission and distribution network will be described with particular attention to: the main electro-optical cable, on shore and deep sea power conversion, the subsea distribution network and connection systems, together with installation and maintenance issues.

Current redistribution in cables made of insulated, soldered, or oxidized strands

International Nuclear Information System (INIS)

Turck, B.

1979-07-01

Current redistributions are compared in cables made of insulated strands, soldered, or oxidized strands and insulated strands with periodic joints. After discussing the different current redistributions in the cases of a rapidly changing current and a dc current, several particular situations are investigated: what happens if a strand is broken, or if a local normal zone appears that does not affect all the strands equally, the detection of this normal zone, and the influence of short circuits between strands

Superconducting ac cable

Science.gov (United States)

Schmidt, F.

1980-11-01

The components of a superconducting 110 kV ac cable for power ratings or = 2000 MVA were developed. The cable design is of the semiflexible type, with a rigid cryogenic envelope containing a flexible hollow coaxial cable core. The cable core consists of spirally wound Nb-A1 composite wires electrically insulated by high pressure polyethylene tape wrappings. A 35 m long single phase test cable with full load terminals rated at 110 kV and 10 kA was constructed and successfully tested. The results obtained prove the technical feasibility and capability of this cable design.

Superconducting ac cable

International Nuclear Information System (INIS)

Schmidt, F.

1980-01-01

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.) [de

Impact of DC link control strategies on the power-flow convergence of integrated AC–DC systems

Directory of Open Access Journals (Sweden)

Shagufta Khan

2016-03-01

Full Text Available For the power-flow solution of integrated AC–DC systems, five quantities are required to be solved per converter, against three independent equations available. These three equations consist of two basic converter equations and one DC network equation, corresponding to each converter. Thus, for solution, two additional equations are required. These two equations are derived from the control specifications adopted for the DC link. Depending on the application, several combinations of valid control specifications are possible. A set of valid control specifications constitutes a control strategy. It is observed that the control strategy adopted for the DC link strongly affects the power-flow convergence of integrated AC–DC systems. This paper investigates how different control strategies affect the power flow convergence of integrated AC–DC systems. Sequential method is used to solve the DC variables in the Newton Raphson (NR power flow model. Seven typical control strategies have been taken into consideration. This is validated by numerous case studies carried out with multiple DC links incorporated in the IEEE 118-bus and 300-bus test systems.

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

Directory of Open Access Journals (Sweden)

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.

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

Science.gov (United States)

Xie, Xu; Li, Xiaozhang; Shen, Yonggang

2014-06-23

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.

Low cost automatic cable winder for industrial radiography projector

International Nuclear Information System (INIS)

Nor Arymaswati Abdullah; Abdul Nassir Ibrahim; Shaharudin Sayuti; Glam Hadzir Patai Mohamad; Masrol Nizam Salleh; Arshad Yasin; Nur Aira Abdul Rahman

2009-04-01

Radiography is a well-established technique that is widely used to detect internal flaws in welds, castings and to check for misconstruction in assemblies. In general it is to verify weld quality in engineering structures such as the fabrication of pressure vessels, pipelines and storage tanks. It can be used on all metals, from light metals such as aluminium to dense metals such as lead. One of the techniques is industrial radiography projector. Industrial radiography projector is used to store radioactive materials when it is not required to expose the material under test. The projector will come together with a guide tube and control unit (cable winder and drive cable). When the source is to be used to radiograph an item, the cable winder will wind-out the source from projector to the desired location through a guide tube. Upon completion of the work the source will be retracted back into its safe shielded position in this projector. In common procedure, the operator has to be close to the exposures projector while wind-out or wind-in the source from and into the projector. This made the radiography operator receive the highest exposure among the radiation operator and this agreed by IAEA. This paper describes a winder cable that can be used to guide the movement of radiography source out of and into the projector that can be controlled by a remote control system. The system comprises of a gear, reversible motor and low frequency automatic controller. This system is powered by DC chargeable battery. (author)

Parametric studh on coupling loss in subsize ITER Nb3Sn cabled specimens

NARCIS (Netherlands)

Nijhuis, Arend; ten Kate, Herman H.J.; 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

Static and Dynamic Mechanical Properties of Long-Span Cable-Stayed Bridges Using CFRP Cables

Directory of Open Access Journals (Sweden)

Mei Kuihua

2017-01-01

Full Text Available The elastic modulus and deadweight of carbon fiber-reinforced polymer (CFRP cables are different from those of steel cables. Thus, the static and dynamic behaviors of cable-stayed bridges using CFRP cables are different from those of cable-stayed bridges using steel cables. The static and dynamic performances of the two kinds of bridges with a span of 1000 m were studied using the numerical method. The effects of geometric nonlinear factors on static performance of the two kinds of cable-stayed bridges were analyzed. The live load effects and temperature effects of the two cable-stayed bridges were also analyzed. The influences of design parameters, including different structural systems, the numbers of auxiliary piers, and the space arrangement types of cable, on the dynamic performance of the cable-stayed bridge using CFRP cables were also studied. Results demonstrate that sag effect of the CFRP cable is much smaller than that of steel cable. The temperature effects of CFRP cable-stayed bridge are less than those of steel cable-stayed bridge. The vertical bending natural vibration frequency of the CFRP cable-stayed bridge is generally lower than that of steel cable-stayed bridge, whereas the torsional natural vibration frequency of the former is higher than that of the latter.

On the Minimum Cable Tensions for the Cable-Based Parallel Robots

Directory of Open Access Journals (Sweden)

Peng Liu

2014-01-01

Full Text Available This paper investigates the minimum cable tension distributions in the workspace for cable-based parallel robots to find out more information on the stability. First, the kinematic model of a cable-based parallel robot is derived based on the wrench matrix. Then, a noniterative polynomial-based optimization algorithm with the proper optimal objective function is presented based on the convex optimization theory, in which the minimum cable tension at any pose is determined. Additionally, three performance indices are proposed to show the distributions of the minimum cable tensions in a specified region of the workspace. An important thing is that the three performance indices can be used to evaluate the stability of the cable-based parallel robots. Furthermore, a new workspace, the Specified Minimum Cable Tension Workspace (SMCTW, is introduced, within which all the minimum tensions exceed a specified value, therefore meeting the specified stability requirement. Finally, a camera robot parallel driven by four cables for aerial panoramic photographing is selected to illustrate the distributions of the minimum cable tensions in the workspace and the relationship between the three performance indices and the stability.

Universal Cable Brackets

Science.gov (United States)

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.

Wind-induced cable vibrations and countermeasures of cables of PC cable-stayed bridge. PC syachokyo keburu no kaze ni yoru shindo to sono taisaku

Energy Technology Data Exchange (ETDEWEB)

Yoneda, M. (Kawada Industries Inc., Tokyo (Japan))

1994-05-01

In recent years, long span of cable-stayed bridges is remarkable. The wind-induced cable vibration called as line vibration and wake galloping was given as an important problem not only in the steel cable-stayed bridges but also in the PC cable-stayed bridges. The technical engineers in design of the cable-stayed bridges have many times to confront the problems on the vibration control of cables, it is considered that sufficient understand of the wind-induced vibration and countermeasures for cables of the PC cable-stayed bridges is necessary. Many reports on the countermeasure examples and trend of vibration control centred on cables of the cable-stayed bridges have been published. In this paper, the wind-induced vibration of cables in the cable-stayed bridges was reviewed, the examples of countermeasures of vibration control on cables in the PC cable-stayed bridges was mainly introduced. The remaining tasks and future prospects on vibration control of the PC cable-stayed bridges were described. 14 refs., 13 figs., 4 tabs.

Plate impact experiments on DC745U cooled to ~ -60 °C

Energy Technology Data Exchange (ETDEWEB)

Gustavsen, Richard L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Dattelbaum, Dana M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Bartram, Brian Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Gibson, Lloyd Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Jones, Justin Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics; Goodbody, Austin Bernard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Shock and Detonation Physics

2016-08-11

Using gas-gun driven plate impact experiments, we have measured the U_S - u_p Hugoniot of the silicone elastomer DC745U cooled to -60 °C. In summary, the initial density changes from p₀ (23°C) = 1.312 ± 0.010 g/cm³ to p₀ (-60°C) = 1.447 ± 0.011 g/cm³. The linear U_S - u_p Hugoniot changes from U_S = 1.62 + 1.74u_p km/s at +23°C, to U_S = 2.03 ± 0.06 + (2.03 ± 0.06) u_p km/s at -60°C. DC745U, therefore is much stiffer at -60°C than at +23°C, probably due to the crystallization that occurs at ~ -50°C. Caveats/deficiencies: 1) This report does not provide an adequate pedigree of the DC745U used. 2) References to unpublished room temperature shock compression data on the elastomer are inadequate. 3) The report has not been fact checked by a DC745 subject matter expert.

Lightning in hybrid cable-overhead lines and consequent transient overvoltages

DEFF Research Database (Denmark)

Silva, Filipe Miguel Faria da; Schultz Pedersen, Kasper; Bak, Claus Leth

2017-01-01

Whereas lines that consist entirely of underground cable are naturally protected from lightning, the phenomenon must be considered for lines that are a mix of overhead lines and underground cables. The difference between overhead lines and underground cables wave impedances may lead to transient ...... conductor and for hits on the earth wire, with and without back flashover. For the most common situation, stroke on the earth wire, it is demonstrated that the cable’s ground propagation mode is dominant, reducing the impact of the reflections....

The Thermal Regime Around Buried Submarine High-Voltage Cables

Science.gov (United States)

Emeana, C. J.; Dix, J.; Henstock, T.; Gernon, T.; Thompson, C.; Pilgrim, J.

2015-12-01

The expansion of offshore renewable energy infrastructure and the desire for "trans-continental shelf" power transmission, all require the use of submarine High Voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70oC and are typically buried at depths of 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the thermal properties of near surface shelf sediments are poorly understood and this increases the uncertainty in determining the required cable current ratings, cable reliability and the potential effects on the sedimentary environments. We present temperature measurements from a 2D laboratory experiment, designed to represent a buried, submarine HV cable. We used a large (2.5 m-high) tank, filled with water-saturated ballotini and instrumented with 120 thermocouples, which measured the time-dependent 2D temperature distributions around the heat source. The experiments use a buried heat source to represent a series of realistic cable surface temperatures with the aim for identifying the thermal regimes generated within typical non-cohesive shelf sediments: coarse silt, fine sand and very coarse sand. The steady state heat flow regimes, and normalised and radial temperature distributions were assessed. Our results show that at temperatures up to 60°C above ambient, the thermal regimes are conductive for the coarse silt sediments and convective for the very coarse sand sediments even at 7°C above ambient. However, the heat flow pattern through the fine sand sediment shows a transition from conductive to convective heat flow at a temperature of approximately 20°C above ambient. These findings offer an important new understanding of the thermal regimes associated with submarine HV cables buried in different substrates and has huge impacts on cable ratings as the IEC 60287 standard only considers conductive heat flow as well as other potential near surface impacts.

Cable aging management

International Nuclear Information System (INIS)

Anandkumaran, A.; Sedding, H.

2012-01-01

Worldwide, due to the age of the majority of nuclear generating stations significant attention is being paid to the condition of the major components, e.g., reactor, steam generator, turbine generator, transformer, etc., with respect to relicensing and life extension. However, there is recognition that cable systems are critical to the safe, reliable and economic operation of nuclear power plants. Consequently, there is great interest in ageing management of low and medium voltage cables in the nuclear environment. Successful implementation of such programs requires an understanding of how the materials associated with cables and their accessories behave under normal operating and accident conditions. However, there is also a great need to determine the actual condition of the materials and systems in order to make rational decisions on whether or not to replace cables to ensure long term assurance of reliable operation. This proposed contribution describes an approach to cable ageing management of low and medium voltage cables based on measurements of material and electrical properties obtained in the laboratory and in the field. The effectiveness of various chemical, mechanical and electrical test methods are discussed in the context of, • Cable configuration, i.e., low or medium voltage, shielded or unshielded • Material type, i.e., PVC, XLPE, EPR, etc., • Ageing stress, i.e., electrical, thermal, radiation, thermal plus radiation, etc. These factors are key to identifying the most appropriate test method (or methods) to enable understanding of the current condition of the cable. While electrical test methods, e.g., ac withstand testing, partial discharge and various dielectric loss measurement techniques have been found effective for medium voltage cables, they are of very limited use on low voltage cables that constitute the majority of cables in nuclear power plants. This limited effectiveness is due to the lack of a well defined ground plane that is a

PID controller simulator software for DC motor of gamma scanning

International Nuclear Information System (INIS)

Arjoni Amir

2008-01-01

Mostly PID controller (Proportional-Integral-Derivative) has been used in industry. For certain applications, it can be used as a Proportional (P) model only, or as a Proportional-Integral (PI) model. The aim of this paper is to design a PID controller simulator software for DC motor which is used in gamma scanning system. A DC motor is described as a plant of SISO (Single Input Single Output) which is used for pulling down the load (detector + casing) and gamma radiation source (Co-60 + container) by using sling cable. A DC motor consist of an armature and a rotor, the equivalent circuit of DC motor is shown in a transfer function equation between output parameter (angular speed DC motor) and input parameter (voltage of DC motor). Methods used for the process of PID controller design is to arrange the PID controller parameter (Kc, Ti, Td) so that there are more PID controller transfer function model which are able to control angular speed of DC motor in stable condition, as design criteria requirement is needed. Design criteria requirement for control system are the settling time < 3 second, overshoot < 5%, rise time = 0.25 second, steady state gain = 1 and peak time < 3 second with step response reference 1 rad/second. The result of simulation gives several models of PID controller in function transfer equation which is similar with design criteria requirement in a equation of function transfer of order 2 for numerator and order 1 for denominator. (author)

DC Voltage Droop Control Structures and its Impact on the Interaction Modes in Interconnected AC-HVDC Systems

DEFF Research Database (Denmark)

Thams, Florian; Chatzivasileiadis, Spyros; Eriksson, Robert

2017-01-01

Different dc voltage droop control structures for future multi-terminal HVDC systems have been proposed in literature. This paper contributes to the evaluation of those structures by an analysis of their impact on the coupling of the interconnected subsystems. In particular, the modes...... of the systems are classified in different subsets according to the participation of the various subsystems. Those subsets are then evaluated qualitatively and quantitatively indicating which impact the choice of the droop control structure has on the degree of coupling between the connected ac and dc systems...

World's longest underwater line part of new dc transmission link

Energy Technology Data Exchange (ETDEWEB)

1967-04-01

The world's seventh dc transmission system including the world's longest underwater power cable is now operative. The system, linking the Italian Mainland with Sardinia, was designed and engineered by the English Electric Co. Ltd. It will ensure a constant power supply for Sardinia and allow export of 200 MW of power to the Tuscany area in Italy. Proving test began on the link in Decmeber and continued until full demand is made on it from Italy.

Comparison study of cable geometries and superconducting tape layouts for high-temperature superconductor cables

Science.gov (United States)

Ta, Wurui; Shao, Tianchong; Gao, Yuanwen

2018-04-01

High-temperature superconductor (HTS) rare-earth-barium-copper-oxide (REBCO) tapes are very promising for use in high-current cables. The cable geometry and the layout of the superconducting tapes are directly related to the performance of the HTS cable. In this paper, we use numerical methods to perform a comparison study of multiple-stage twisted stacked-tape cable (TSTC) conductors to find better cable structures that can both improve the critical current and minimize the alternating current (AC) losses of the cable. The sub-cable geometry is designed to have a stair-step shape. Three superconducting tape layouts are chosen and their transport performance and AC losses are evaluated. The magnetic field and current density profiles of the cables are obtained. The results show that arrangement of the superconducting tapes from the interior towards the exterior of the cable based on their critical current values in descending order can enhance the cable's transport capacity while significantly reducing the AC losses. These results imply that cable transport capacity improvements can be achieved by arranging the superconducting tapes in a manner consistent with the electromagnetic field distribution. Through comparison of the critical currents and AC losses of four types of HTS cables, we determine the best structural choice among these cables.

Cable Supported Bridges

DEFF Research Database (Denmark)

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...... to quantify the different structural configurations and allows a preliminary optimization of the main structure.Included are the most recent advances in structural design, corrosion protection of cables, aerodynamic safety, and erection procedures....

Surface Layer Fluorination-Modulated Space Charge Behaviors in HVDC Cable Accessory

Directory of Open Access Journals (Sweden)

Jin Li

2018-05-01

Full Text Available Space charges tend to accumulate on the surface and at the interface of ethylene–propylene–diene terpolymer (EPDM, serving as high voltage direct current (HVDC cable accessory insulation, which likely induces electrical field distortion and dielectric breakdown. Direct fluorination is an effective method to modify the surface characteristics of the EPDM without altering the bulk properties too much. In this paper, the surface morphology, hydrophobic properties, relative permittivity, and DC conductivity of the EPDM before and after fluorination treatment were tested. Furthermore, the surface and interface charge behaviors in the HVDC cable accessory were investigated by the pulsed electroacoustic (PEA method, and explained from the point of view of trap distribution. The results show that fluorination helps the EPDM polymer obtain lower surface energy and relative permittivity, which is beneficial to the interface match in composite insulation systems. The lowest degree of space charge accumulation occurs in EPDM with 30 min of fluorination. After analyzing the results of the 3D potentials and the density of states (DOS behaviors in EPDM before and after fluorination, it can be found that fluorination treatment introduces shallower electron traps, and the special electrostatic potential after fluorination can significantly suppress the space charge accumulation at the interface in the HVDC cable accessory.

Characterization of diode valve in medium voltage dc/dc converter for wind turbines

DEFF Research Database (Denmark)

Dincan, Catalin Gabriel; Kjær, Philip Carne

2016-01-01

This paper proposes a methodology for characterization of medium voltage (MV), medium frequency (MF) rectifier diode valve. The intended application is for 10MW dc/dc converters used in DC offshore wind turbines. Sensitivity to semiconductor component parameter variation, snubber component tolera...... tolerance, influence of temperature and stray capacitance are analyzed. It is concluded that the largest impact on sensitivity is given by reverse recovery charge variation and differences of temperature between adjacent devices....

30 CFR 77.601 - Trailing cables or portable cables; temporary splices.

Science.gov (United States)

2010-07-01

... LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Trailing Cables § 77.601 Trailing cables or portable cables; temporary... or splices that heat or spark under load shall not be used. ...

Ageing of instrumentation and control cables in NPPs

International Nuclear Information System (INIS)

Santhosh; Ghosh, A.K.; Fernandes, B.G.

2011-01-01

Cables are vital components of instrumentation and control (I and C) systems in nuclear power plants (NPPs). The polymer materials used for insulation and jacket materials for electric cables are susceptible to ageing and degradation mechanisms caused by exposure to many of the stressors encountered in NPP service conditions. Ageing of components in NPP is an important concern since the degradation caused by ageing can impact the performance of susceptible equipment. This is of particular concern for safety-related equipment since the failure due to ageing can compromise the continued safe operation of the plant. The state-of-the art for incorporating cable ageing effects into probabilistic safety assessment (PSA) is still evolving and in the reliability assessment of NPP systems, the ageing effect of electrical cable is generally not considered and also, there is no standard method exists for incorporating such ageing effects into the system reliability. Therefore, identification and quantification of ageing of electrical cables is very much essential for an accurate prediction of system reliability for PSA applications. The objective of this study is to develop a methodology to assess the susceptibility of polymeric cable insulation to various ageing mechanisms; and the state of the insulation at any chosen time in order to evaluate the remaining life-time of operating cables in NPPs. This paper presents the state-of-the-art tools and techniques for insulation condition assessment, insulation life prediction methodologies, equipment qualification guidelines, and ageing management programs relating to I and C cables in NPPs. An approach to calculate the insulation resistance subjecting to different stressors has also been presented in this paper. (author)

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

Science.gov (United States)

Sun, Bing-nan; Wang, Zhi-gang; Ko, J M; Ni, Y Q

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.

Magnet cable manufacturing

International Nuclear Information System (INIS)

Royet, J.

1985-07-01

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

Impact of Faults and Protection Methods on DC Microgrids Operation

DEFF Research Database (Denmark)

Bayati, Navid; Hajizadeh, Amin; N. Soltani, Mohsen

2018-01-01

with the DC Microgrid. This paper evaluates and presents a comprehensive review on the most recent studies in the DC Microgrids protection. Moreover, the fault behavior and characteristics of DC Microgrids, the effect of Constant Power Load (CPL) , and recent DC Microgrid protection methods are reviewed. Also...

Cable strengthened arches

NARCIS (Netherlands)

Kamerling, M.W.

2013-01-01

The structural efficiency of arches, subjected to several variable loads, can be increased by strengthening these arches with cables. For these structures it can be necessary, especially in case the permanent load is small, to post-tension the cables to avoid any compression acting on the cables. A

A new multiconstraint method for determining the optimal cable stresses in cable-stayed bridges.

Science.gov (United States)

Asgari, B; Osman, S A; Adnan, A

2014-01-01

Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

A New Multiconstraint Method for Determining the Optimal Cable Stresses in Cable-Stayed Bridges

Directory of Open Access Journals (Sweden)

B. Asgari

2014-01-01

Full Text Available Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM. The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS

International Nuclear Information System (INIS)

Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun

2012-01-01

The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS

Energy Technology Data Exchange (ETDEWEB)

Dinh, Minh-Chau, E-mail: thanchau7787@gmail.com [Changwon National University, 9 Sarim-Dong, Changwon 641-733 (Korea, Republic of); Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon [Changwon National University, 9 Sarim-Dong, Changwon 641-733 (Korea, Republic of); Yu, In-Keun, E-mail: yuik@changwon.ac.kr [Changwon National University, 9 Sarim-Dong, Changwon 641-733 (Korea, Republic of)

2012-08-15

The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

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

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Sizewell 'B' cable installation

International Nuclear Information System (INIS)

Gemmell, D.R.

1992-01-01

N G Bailey and Co. Ltd., UK were awarded the contract for the procurement, manufacture, works testing, works finishing, supply, delivery, off-loading, storage, installation, site finishing, preservation, setting to work and site testing of the following; the main cable installation throughout the Station including the addition of the Radioactive Waste Building, earthing and lightning protection installation, cable supporting steelwork and carriers and glanding and termination of cables. The cabling installation comprises power distribution, control and instrumentation cabling including all the associated cabling accessories, terminal boxes and similar components. The way that the contract was set-up, awarded and is now being carried out is described. Planning and industrial relations have been key features of the contract. (Author)

Seismic Passive Control of Cable-Stayed Bridges

Directory of Open Access Journals (Sweden)

Hosam-Eddin M. Ali

1995-01-01

Full Text Available A three-dimensional modeling procedure is proposed for cable-stayed bridges with rubber, steel, and lead energy dissipation devices. The passive control technique is investigated by considering the response of bridge models with and without energy dissipation devices. The impact of various design parameters on the seismic response of current and future bridge designs is studied. Appropriate locations and properties of the passive devices can achieve better performance for cable-stayed bridges by balancing the significant reduction in earthquake-induced forces against tolerable displacements. Proper design of passive systems can help provide solutions for retro-fitting some existing bridges.

What threat do turbidity currents and submarine landslides pose to submarine telecommunications cable infrastructure?

Science.gov (United States)

Clare, Michael; Pope, Edward; Talling, Peter; Hunt, James; Carter, Lionel

2016-04-01

The global economy relies on uninterrupted usage of a network of telecommunication cables on the seafloor. These submarine cables carry ~99% of all trans-oceanic digital data and voice communications traffic worldwide, as they have far greater bandwidth than satellites. Over 9 million SWIFT banks transfers alone were made using these cables in 2004, totalling 7.4 trillion of transactions per day between 208 countries, which grew to 15 million SWIFT bank transactions last year. We outline the challenge of why, how often, and where seafloor cables are broken by natural causes; primarily subsea landslides and sediment flows (turbidity currents and also debris flows and hyperpycnal flows). These slides and flows can be very destructive. As an example, a sediment flow in 1929 travelled up to 19 m/s and broke 11 cables in the NE Atlantic, running out for ~800 km to the abyssal ocean. The 2006 Pingtung earthquake triggered a sediment flow that broke 22 cables offshore Taiwan over a distance of 450 km. Here, we present initial results from the first statistical analysis of a global database of cable breaks and causes. We first investigate the controls on frequency of submarine cable breaks in different environmental and geological settings worldwide. We assess which types of earthquake pose a significant threat to submarine cable networks. Meteorological events, such as hurricanes and typhoons, pose a significant threat to submarine cable networks, so we also discuss the potential impacts of future climate change on the frequency of such hazards. We then go on to ask what are the physical impacts of submarine sediment flows on submerged cables? A striking observation from past cable breaks is sometimes cables remain unbroken, whilst adjacent cables are severed (and record powerful flows travelling at up to 6 m/s). Why are some cables broken, but neighbouring cables remain intact? We provide some explanations for this question, and outline the need for future in

Cable laying methods in a multi-cable elevator system

Energy Technology Data Exchange (ETDEWEB)

Dvornikov, V.I.; Makhinyan, V.V.

1984-01-01

Based on the solution of differential equations describing the stress and deformation state of cables during rolling on the drum, a conclusion is made concerning a rational method for hanging cables with a free-spinning end.

DC electric springs with DC/DC converters

DEFF Research Database (Denmark)

Wang, Qingsong; Cheng, Ming; Jiang, Yunlei

2016-01-01

The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi-directio......The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi...... and/or constant discharging for batteries is adopted and four operating modes are analyzed as charging-positive, charging-negative, discharging-positive and discharging-negative modes. An additional mechanism for fast charging or fast discharging is also designed to secure normal operation...... of batteries. With the proposed DCES, the power fluctuations due to intermittent RESs can be passed to non-critical loads (NCLs) and batteries while power on critical loads (CLs) is kept stable. This is possibly the first attempt to design a DCES with only DC/DC converters. The performances of the proposed...

The Impact of Grid Unbalances on the Reliability of DC-link Capacitors in a Motor Drive

DEFF Research Database (Denmark)

Wang, Huai; Davari, Pooya; Kumar, Dinesh

2017-01-01

DC-link capacitor is one of the reliability-critical components in motor drive applications, which contributes to a considerable cost, size and failure. Its reliability performance depends on both inherent physical strength and external loading. The grid unbalances could alter the electro......-thermal stresses of key components in a motor drive. Therefore, this digest investigates the impact of grid voltage amplitude and phase unbalances on the lifetime of DC-link capacitors used in a standard three-phase motor drive. The theoretical stress models and experimental measurements of the capacitor voltages...... and ripple currents are presented. The relationship between the DC-link capacitor lifetime and the level of unbalances and loads are discussed based on a 7.5 kW motor drive system. The results serve as a guideline to size the DC-link capacitors to be robust enough at the presence of grid unbalance conditions....

Measurement and Analysis of Magnetic Field Radiated from D.C. Tramway: A case study for Tunis’s metro

Directory of Open Access Journals (Sweden)

J. Ben Hadj Slama

2008-06-01

Full Text Available High-power electrical drives, subsystems, and equipment mounted on board of rolling stock make the internal environment potentially harsh from the point of view of electromagnetic (EM field emissions. In particular, at low frequencies, electronically controlled power drive systems behave as effective emission sources. This paper deals with characterization of electromagnetic field radiated from D.C. railway systems. The D.C. railway system of Tunis’s urban electric metro is described. The magnetic field is measured at different points inside and near the moving D.C. train. Measurement results are presented and analyzed. Analysis of measurement results shows that, within frequency range 100kHz-20MHz, the radiated magnetic field is coming from power electronic systems embedded on the train. In particular, choppers, D.C. motors and their connecting cables represent the most important emitting source of magnetic field in the D.C. tramway.

Design and test of low-capacitance, air-insulated, 80-kV, 0.5-sec source cables for MFTF sustaining-neutral-beam power supples

International Nuclear Information System (INIS)

Mayhall, D.J.; Wilson, J.H.; Caldwell, W.J.; Watson, T.F.; Jenkins, J.W. Jr.

1981-01-01

The design of air-insulated cables, which meet strict requirements, is described. Inductance, heat transfer, and electrostatic computer codes are used in design. Tests include electric circiut parameters, dc voltage holdoff, impulse voltage holdoff, heat rise at greater than peak duty, and shield mechanical strength

High Temperature Superconducting Underground Cable

International Nuclear Information System (INIS)

Farrell, Roger A.

2010-01-01

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.

Cable Diagnostic Focused Initiative

Energy Technology Data Exchange (ETDEWEB)

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

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

Directory of Open Access Journals (Sweden)

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.

Cable support arrangements

International Nuclear Information System (INIS)

Pendleton, E.; Murray, A.

1983-01-01

A cable support arrangement extending from a refuelling level floor of a nuclear reactor to the inner shield of a double rotatable shield comprises a linearly extensible cable support and disciplining boom, reaching from the floor to the main shield, and a circumferentially extensible cable support and disciplining means running from the end of the boom to a fixed end on the inner shield. (author)

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

DEFF Research Database (Denmark)

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 cy...

Advanced DC/DC converters

CERN Document Server

Luo, Fang Lin

2003-01-01

DC/DC conversion techniques have undergone rapid development in recent decades. With the pioneering work of these authors, DC/DC converters have now moved into their sixth generation. This book offers a concise, practical presentation of DC/DC converters, summarizing the spectrum of conversion tecnologies and presentingmany new ideas and more than 100 new topologies. Nowhere else in the literature are DC/DC converters so logically sorted and systematically introduced, and nowhere else can readers find detailed information on prototype topologies that represent a major contribution to modern power engineering. More than 320 figures, 60 tables, and 500 formulae facilitate understand and provide precise data.

30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of electric... material and 21/2 inches of conductor insulation. The type, amperage, voltage rating, and construction of...

Operation and control of a DC-grid offshore wind farm under DC transmission system faults

DEFF Research Database (Denmark)

Deng, Fujin; Chen, Zhe

2013-01-01

. Consequently, the protection and control strategies of dc systems need to be established. This paper studies a dc-grid offshore wind farm, where the wind power collection system and power transmission system adopt dc technology. In this paper, the redundancy of the HVDC transmission system under faults...... is studied, and a fault ridethrough strategy for the dc-grid offshore wind farm is proposed. The proposed strategy can effectively minimize the impacts of the power transmission system disturbance on the offshore wind farm, and on the ac grid. A dc-grid offshore wind farm example is simulated with PSCAD....../EMTDC, and the results validate the feasibility of the presented redundancy configuration and operation approach, and the fault ridethrough control strategy....

A Unidirectional DC-DC Autotransformer for DC Grid Application

Directory of Open Access Journals (Sweden)

Meng Zhou

2018-03-01

Full Text Available Conventional unidirectional DC-DC converters for DC grid application employ DC-AC-DC two-stage conversion technology and suffer from high converter cost and power loss. To solve these issues, a unidirectional step-up DC-DC autotransformer (UUDAT and a unidirectional step-down DC-DC autotransformer (DUDAT are studied. The UUDAT and DUDAT are composed of a series connection of diode bridges and voltage source converters. Topologies of UUDAT and DUDAT are detailed. The harmonic and un-controllability issues are discussed. Control and possible application scenarios for UUDAT and DUDAT are depicted. DC fault isolation mechanism and the methods of dimensioning the voltage and power ratings of the components in UUDAT and DUDAT are studied. Extensive simulations on power system level and experiments on a UUDAT and DUDAT prototype verified their technical feasibility.

COPPER CABLE RECYCLING TECHNOLOGY

International Nuclear Information System (INIS)

Chelsea Hubbard

2001-01-01

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

NRC Information Notice No. 92-01: Cable damage caused by inadequate cable installation procedures and controls

International Nuclear Information System (INIS)

Rossi, C.E.

1993-01-01

In June 1989, the Tennessee Valley Authority (TVA) removed the cables from a conduit in the reactor protection system of the Watts Bar Nuclear Plant, Unit 2, to inspect for damage. TVA selected this conduit in response to an employee's concern that a welding arc that struck the conduit in response to an employee's concern that a welding arc that struck the conduit during construction may have damaged cables in the conduit. When the cables were removed, TVA found significant damage in the insulation of some cables. This damage was not attributed to heat generated by the alleged welding arc. The damage was principally attributed to the pulling stresses exerted during the initial installation of the cables. Some of the cables had insulation removed down to the conductors. To assess the extent of cable damage and determine the scope of its investigation, TVA removed more cables from conduits that constituted the most difficult pulls (worst case) and found varying degrees of damage that it attributed to pulling stresses. To fill a conduit at Watts Bar, personnel used pull cords to pull more cables through the conduits over the top of existing cables. This practice is called ''pull-by.'' This practice can cause damage to the existing cables from the sawing action of the pull cords and the friction of cables as they are pulled over existing cables. TVA instituted programs to assess the adequacy of cable installation at all its nuclear facilities and take appropriate corrective actions. At Watts Bar, TVA replaced cables in conduits which exceeded a calculated threshold value of side wall bearing pressure (SWBP) and performed a high-potential (hi-pot) tests on a number of other cables in conduits with SWBP below the calculated threshold value

DC Rocks! Using Place-Based Learning to Introduce Washington DC's K-12 Students to the Geosciences

Science.gov (United States)

Mayberry, G. C.; Mattietti, G. K.

2017-12-01

The Washington DC area has interesting geology and a multitude of agencies that deal with the geosciences, yet K-12 public school students in DC, most of whom are minorities, have limited exposure to the geosciences. Geoscience agencies in the DC area have a unique opportunity to address this by introducing the geosciences to local students who otherwise may not have such an opportunity, by highlighting the geology in the students' "backyard," and by leveraging partnerships among DC-based geoscience-related agencies. The USGS and George Mason University are developing a project called DC Rocks, which will give DC's students an exciting introduction into the world of geoscience with place-based learning opportunities that will make geoscience relevant to their lives and their futures. Both the need in DC and the potential for lasting impact are great; the geosciences have the lowest racial diversity of all the science, technology, engineering, and math (STEM) fields, 89% of students in DC public schools are minorities, and there is no dedicated geoscience curriculum in DC. DC Rocks aims to give these students early exposure to the earth sciences, and encourage them to consider careers in the profession. DC Rocks will work with partner agencies to apply several methods that are recommended by researchers to increase the participation of minority students in the geosciences, including providing profoundly positive experiences that spark interest in the geosciences (Levine et al., 2007); increasing students' sense of belonging in the geosciences (Huntoon, et al, 2016); and place-based teaching practices that emphasize the study of local sites (Semken, 2005), such as DC's Rock Creek Park. DC Rocks will apply these methods by coordinating local geoscientists and resources to provide real-world examples of the geosciences' impact on students' lives. Through the DC Rocks website, educators will be able to request geoscience-related resources such as class presentations by

Energy cable engineering. Energiekabeltechnik

Energy Technology Data Exchange (ETDEWEB)

Luecking, H W

1981-01-01

This textbook intends to explain cable elements and common cable constructions according to VDE, and in a second part, to review the theoretical fundamentals and their consequences with a view to the construction of cables for higher voltages and powers. It will give the student a picture of the variety of problems and solutions which make cable engineering so interesting and show the practising engineer how to derive a theoretical system from their extensive everyday experience.

High temperature superconductors as a technological discontinuity in the power cable industry

Energy Technology Data Exchange (ETDEWEB)

Beales, T.P.; McCormack, J.S. [BICC Cables Ltd., Hebburn (United Kingdom)

1994-12-31

The advent of superconductivity above 77 K represents to the power cable industry a technological discontinuity analogous to that seen in the copper telecommunications industry by the arrival of optical fibres. This phenomenon is discussed along with technical criteria and performance targets needed for high temperature superconducting wire to have an economic impact in transmission cables.

High temperature superconductors as a technological discontinuity in the power cable industry

International Nuclear Information System (INIS)

Beales, T.P.; McCormack, J.S.

1994-01-01

The advent of superconductivity above 77 K represents to the power cable industry a technological discontinuity analogous to that seen in the copper telecommunications industry by the arrival of optical fibres. This phenomenon is discussed along with technical criteria and performance targets needed for high temperature superconducting wire to have an economic impact in transmission cables

Corrosion study on high power feeding of telecomunication copper cable in 5 wt.% CaSO4.2H2O solution

Science.gov (United States)

Shamsudin, Shaiful Rizam; Hashim, Nabihah; Ibrahim, Mohd Saiful Bahri; Rahman, Muhammad Sayuzi Abdul; Idrus, Muhammad Amin; Hassan, Mohd Rezadzudin; Abdullah, Wan Razli Wan

2016-07-01

The studies were carried out to find out the best powering scheme over the copper telephone line. It was expected that the application of the higher power feeding could increase the data transfer and capable of providing the customer's satisfaction. To realize the application of higher remote power feeding, the potential of corrosion problem on Cu cables was studied. The natural corrosion behaviour of copper cable in the 0.5% CaSO4.2H2O solution was studied in term of open circuit potential for 30 days. The corrosion behaviour of higher power feeding was studied by the immersion and the planned interval test to determine the corrosion rate as well as the effect of voltage magnitudes and the current scheme i.e. positive direct (DC+) and alternating current (AC) at about 0.40 ± 0.01 mA/ cm2 current density. In the immersion test, both DC+ and AC scheme showed the increasing of feeding voltage magnitude has increased the corrosion rate of Cu samples starting from 60 to 100 volts. It was then reduced at about 100 - 120 volts which may due to the passive and transpassive mechanism. The corrosion rate was slowly reduced further from 120 to 200 volts. Visually, the positively charged of Cu cable was seems susceptible to severe corrosion, while AC scheme exhibited a slight corrosion reaction on the surface. However, the planned interval test and XRD results showed the corrosion activity of the copper cable in the studied solution was a relatively slow process and considered not to be corroded as a partially protective scale of copper oxide formed on the surface.

Emerging Subsea Networks: SMART Cable Systems for Science and Society

Science.gov (United States)

Howe, B. M.; Butler, R.; Joint Task Force, U.

2016-02-01

The subsea telecommunications cable industry is approaching a prospective new era: deploying SMART subsea cable systems (SMART = Science Monitoring And Reliable Telecommunication). The current global, commercial cable infrastructure consists of 1 Gm of cable, being refreshed now and expanding in the future. The SMART concept is to add a small external sensor package along the cable system at its optical repeaters to transmit important real-time environmental data via a dedicated wavelength or overhead channel in the transmission system, avoiding any impact on the commercial traffic. These small, reliable, existing sensors would precisely measure temperature, pressure and three-axis acceleration across the world's ocean floor over an extended period of time, being deployed using standard cable-laying procedures on new or refurbished cables, but not requiring maintenance through the 2-3 decade life of the cable systems. The game-changing factor is the urgent international need for ocean environmental data related to mitigating climate and sea-level change and improving tsunami and slope failure hazard warnings. Societal costs incurred by these are reaching billions of dollars and hundreds of thousands of deaths. Pressures for new and urgent public policies are evident from the 5th IPCC Assessment, USA-China agreement on limiting greenhouse gas emissions, clear evidence for rapid global warming, 21st Session of the Conference of the Parties to the UNFCCC (December 2015, Paris), and the scale of the costs of inaction. To support revised public policies and actions, decision-makers, industry leaders, and the public are seeking key scientific data, which will necessitate new sources of funding. Hence, the emergence of new SMART cable systems offered by the subsea telecommunications industry will provide new market opportunities, engage additional non-traditional users, and make profound societal contributions. The Joint Task Force (JTF) on SMART Subsea Cable Systems

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

Energy Technology Data Exchange (ETDEWEB)

Kim, Ju Won; Choi, Jun Sung; Park, Seung Hee [Sungkyunkwan University, Seoul (Korea, Republic of); Lee, Eun Chan [Korea Maintance Co., Ltd., Seoul (Korea, Republic of)

2014-02-15

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.

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

International Nuclear Information System (INIS)

Kim, Ju Won; Choi, Jun Sung; Park, Seung Hee; Lee, Eun Chan

2014-01-01

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.

Electrical power cable engineering

CERN Document Server

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

Experimental investigation into the fault response of superconducting hybrid electric propulsion electrical power system to a DC rail to rail fault

Science.gov (United States)

Nolan, S.; Jones, C. E.; Munro, R.; Norman, P.; Galloway, S.; Venturumilli, S.; Sheng, J.; Yuan, W.

2017-12-01

Hybrid electric propulsion aircraft are proposed to improve overall aircraft efficiency, enabling future rising demands for air travel to be met. The development of appropriate electrical power systems to provide thrust for the aircraft is a significant challenge due to the much higher required power generation capacity levels and complexity of the aero-electrical power systems (AEPS). The efficiency and weight of the AEPS is critical to ensure that the benefits of hybrid propulsion are not mitigated by the electrical power train. Hence it is proposed that for larger aircraft (~200 passengers) superconducting power systems are used to meet target power densities. Central to the design of the hybrid propulsion AEPS is a robust and reliable electrical protection and fault management system. It is known from previous studies that the choice of protection system may have a significant impact on the overall efficiency of the AEPS. Hence an informed design process which considers the key trades between choice of cable and protection requirements is needed. To date the fault response of a voltage source converter interfaced DC link rail to rail fault in a superconducting power system has only been investigated using simulation models validated by theoretical values from the literature. This paper will present the experimentally obtained fault response for a variety of different types of superconducting tape for a rail to rail DC fault. The paper will then use these as a platform to identify key trades between protection requirements and cable design, providing guidelines to enable future informed decisions to optimise hybrid propulsion electrical power system and protection design.

Comparisons of internal self-field magnetic flux densities between recent Nb{sub 3}Sn fusion magnet CICC cable designs

Energy Technology Data Exchange (ETDEWEB)

Kwon, S. P. [National Fusion Research Institute, Daejeon (Korea, Republic of)

2016-09-15

The Cable-In-Conduit-Conductor (CICC) for the ITER tokamak Central Solenoid (CS) has undergone design change since the first prototype conductor sample was tested in 2010. After tests showed that the performance of initial conductor samples degraded rapidly without stabilization, an alternate design with shorter sub-cable twist pitches was tested and discovered to satisfy performance requirements, namely that the minimum current sharing temperature (Tcs) remained above a given limit under DC bias. With consistent successful performance of ITER CS conductor CICC samples using the alternate design, an attempt is made here to revisit the internal electromagnetic properties of the CICC cable design to identify any correlation with conductor performance. Results of this study suggest that there may be a simple link between the Nb3Sn CICC internal self-field and its Tcs performance. The study also suggests that an optimization process should exist that can further improve the performance of Nb3Sn based CICC.

Cable Television: Franchising Considerations.

Science.gov (United States)

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…

Colleges and Cable Franchising.

Science.gov (United States)

Glenn, Neal D.

After noting issues of audience appeal and financial and philosophical support for educational broadcasting, this paper urges community colleges to play an active role in the process of cable franchising. The paper first describes a cable franchise as a contract between a government unit and the cable television (CATV) company which specifies what…

14 CFR 23.689 - Cable systems.

Science.gov (United States)

2010-01-01

... in cable tension throughout the range of travel under operating conditions and temperature variations... 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...

Tension optimization of the conductor-and-support cable elements during stranding process

Directory of Open Access Journals (Sweden)

I.M. Chayun

2016-12-01

Full Text Available Steel lifting ropes, cables and other similar products are rod statically undeterminable prestressed structures. Preliminary deformations of their elements (wires are caused by their manufacturing technology. Wires suffer stretching, bending with torsion in a stage of elastoplastic deformation. In this work the mechanic-mathematical model of residual forces determination in the wires of polymetallic conductor-and-support cable is offered. Aim: The aim of the work is studying of the mechanical and mathematical model defining residual forces in the wires of conductor-and-support cable and also the optimization of parameters of a twist by the criterion of residual forces lack after production process finishing. Materials and methods: The method developed by the authors earlier to the study the strain-stressed state of twisted wire products off-loading from technological internal forces has been applied to assess the impact of the approximate value of the longitudinal stiffness of the product. In this paper, each wire is considered as an element of the product individually. This is necessary to investigate the impact of uneven wire tensions on defects of conductor-and-support cable (out-of-straight in a free state and stripping-down. Results: On the basis of the conducted deformation studies of conductor-and-support cable during off-loading process from twist tension of its elements the dependencies of residual forces on the level and interrelation of elements tension has been determined. The condition of ensuring of zero residual forces in the wires of conductor-and-support cable after production is formulated. It was found that calculated values of residual forces are almost identical when using of the approximate and exact values of longitudinal stiffness of conductor-and-support cable.

Cables - a question of custom-design

International Nuclear Information System (INIS)

Doig, Tom

1994-01-01

Electrical equipment such as cabling can often be the limiting factor as far as machine operations in radioactive environments are concerned. Electronic and electrical equipment will degrade if exposed to ionising radiation, affecting equipment reliability, or causing complete failure. However, several companies provide custom-designed products directed specifically at the nuclear industry. One such company is Habia Cable which has built up its business in submarine cables, internal engine cables, and cables for high fire risk situations. It began supplying custom-designed cables to the nuclear industry in 1986, and has since then supplied cables throughout Europe from its plant in Sweden. (Author)

Proposed superscreened cables and connectors

International Nuclear Information System (INIS)

Fowler, E.P.

1975-11-01

The paper summarises the present availability of superscreened cables and proposes the specification of a family of cables to meet the foreseeable needs of the nuclear power industry. The cable numbering system is described, special tests outlined and important details given for the chosen cables. Appropriate connectors are also discussed and listed with an outline of their required screening performance. (author)

A resonant dc-dc power converter assembly

DEFF Research Database (Denmark)

2015-01-01

The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the s......The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor...... of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or forcing substantially 0 degree phase shift, between corresponding resonant voltage waveforms of the first...

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

Energy Technology Data Exchange (ETDEWEB)

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.

Trenchless Replacement of Buried Cable Lines

Directory of Open Access Journals (Sweden)

Hans-Joachim Bayer

2007-01-01

Full Text Available An enormous amount of underground electricity and telecommunication cables have been worn over the time with technical defects or need capacity increases. Thus, new lines need to be installed. In urban areas, even in smaller communities and in natural reserves, open trenching is difficult and often not permitted.In response, new patented methods of trenchless cable replacement using the HDD equipment have been developed by the TT Group. The new technology is called “Wash-over-cable-replacement” and applies specially designed drill heads, cutting around the old cable string in various configurations (completely closed, U-shape or S-shape embracing, depending to the coating type of the old cable. This special cable replacement drill head separates the cable from the surrounding adhesive soil or the sand bedding by creating a very small annular space around the cable thus enabling the pulling or dragging out of the old cable section between the start and the exit pit. After the old cable has been loosened from the surrounding soil by means of the wash over process and pulled out, the new cable can be smoothly pulled into the void using the drill rods and embedding the new cable in a rich bed of Bentonite.The wash-over drill heads are slim and have inner and outer nozzles for Bentonite and bits to handle roots, pebbles, gravel and the like. These drill heads perform very quickly (up to 3 meters per minute to effectively wash over existing cables without damaging the cable coating and prepare the ground for a fast new laying of a new cable in the existing line. Network owners also benefit from the fact that new geodetic or topographic surveys and documentations of the new cable are not necessary. Only the documents, remarks, technical codes and existing geodetic data need to be updated.The paper will outline the technological background and include several practical job examples.

Cable Aerodynamic Control

DEFF Research Database (Denmark)

Kleissl, Kenneth

to a 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...... been conducted. The two current prevailing systems consisting of helically filleted cables and cables with a pattern-indented surface were directly compared under the same conditions and both applications were found with attractive properties. The pattern-indented surface maintained a low supercritical...... of reducing the intensity of the axial flow and disrupting the near wake flow structures. Similar studies during wet conditions with artificial simulation of light rain in the wind tunnel showed that the plain cable suffered from severe rain-wind induced vibrations. But despite the presence of both upper...

DC-Voltage Fluctuation Elimination Through a DC-Capacitor Current Control for DFIG Converters Under Unbalanced Grid Voltage Conditions

DEFF Research Database (Denmark)

Liu, Changjin; Xu, Dehong; Zhu, Nan

2013-01-01

Unbalanced grid voltage causes a large second-order harmonic current in the dc-link capacitors as well as dc-voltage fluctuation, which potentially will degrade the lifespan and reliability of the capacitors in voltage source converters. This paper proposes a novel dc-capacitor current control...... method for a grid-side converter (GSC) to eliminate the negative impact of unbalanced grid voltage on the dc-capacitors. In this method, a dc-capacitor current control loop, where a negative-sequence resonant controller is used to increase the loop gain, is added to the conventional GSC current control...... loop. The rejection capability to the unbalanced grid voltage and the stability of the proposed control system are discussed. The second-order harmonic current in the dc capacitor as well as dc-voltage fluctuation is very well eliminated. Hence, the dc capacitors will be more reliable under unbalanced...

Shape accuracy optimization for cable-rib tension deployable antenna structure with tensioned cables

Science.gov (United States)

Liu, Ruiwei; Guo, Hongwei; Liu, Rongqiang; Wang, Hongxiang; Tang, Dewei; Song, Xiaoke

2017-11-01

Shape accuracy is of substantial importance in deployable structures as the demand for large-scale deployable structures in various fields, especially in aerospace engineering, increases. The main purpose of this paper is to present a shape accuracy optimization method to find the optimal pretensions for the desired shape of cable-rib tension deployable antenna structure with tensioned cables. First, an analysis model of the deployable structure is established by using finite element method. In this model, geometrical nonlinearity is considered for the cable element and beam element. Flexible deformations of the deployable structure under the action of cable network and tensioned cables are subsequently analyzed separately. Moreover, the influence of pretension of tensioned cables on natural frequencies is studied. Based on the results, a genetic algorithm is used to find a set of reasonable pretension and thus minimize structural deformation under the first natural frequency constraint. Finally, numerical simulations are presented to analyze the deployable structure under two kinds of constraints. Results show that the shape accuracy and natural frequencies of deployable structure can be effectively improved by pretension optimization.

Step-Up DC-DC converters

DEFF Research Database (Denmark)

Forouzesh, Mojtaba; Siwakoti, Yam P.; Gorji, Saman A.

2017-01-01

on the general law and framework of the development of next-generation step-up dc-dc converters, this paper aims to comprehensively review and classify various step-up dc-dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage......DC-DC converters with voltage boost capability are widely used in a large number of power conversion applications, from fraction-of-volt to tens of thousands of volts at power levels from milliwatts to megawatts. The literature has reported on various voltage-boosting techniques, in which......-boosting techniques and associated converters are discussed in detail. Finally, broad applications of dc-dc converters are presented and summarized with comparative study of different voltage-boosting techniques....

Online Location of Faults on AC Cables in Underground Transmission Systems

DEFF Research Database (Denmark)

Jensen, Christian Flytkjær

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-based methods...... connection to verify the proposed method. Faults, at reduced a voltage are artificially applied in the cable system and the transient response is measured at two terminals at the cable’s ends. The measurements are time-synchronised and it is found that a very accurate estimation of the fault location can......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...

A resonant dc-dc power converter assembly

OpenAIRE

Madsen, Mickey Pierre

2015-01-01

The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or fo...

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

Energy Technology Data Exchange (ETDEWEB)

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.

Development of inspection robots for bridge cables.

Science.gov (United States)

Yun, Hae-Bum; Kim, Se-Hoon; Wu, Liuliu; Lee, Jong-Jae

2013-01-01

This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

Photonic-powered cable assembly

Science.gov (United States)

Sanderson, Stephen N.; Appel, Titus James; Wrye, IV, Walter C.

2013-01-22

A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

Optimal Cable Tension Distribution of the High-Speed Redundant Driven Camera Robots Considering Cable Sag and Inertia Effects

Directory of Open Access Journals (Sweden)

Yu Su

2014-03-01

Full Text Available Camera robots are high-speed redundantly cable-driven parallel manipulators that realize the aerial panoramic photographing. When long-span cables and high maneuverability are involved, the effects of cable sags and inertias on the dynamics must be carefully dealt with. This paper is devoted to the optimal cable tension distribution (OCTD for short of the camera robots. Firstly, each fast varying-length cable is discretized into some nodes for computing the cable inertias. Secondly, the dynamic equation integrated with the cable inertias is set up regarding the large-span cables as catenaries. Thirdly, an iterative optimization algorithm is introduced for the cable tension distribution by using the dynamic equation and sag-to-span ratios as constraint conditions. Finally, numerical examples are presented to demonstrate the effects of cable sags and inertias on determining tensions. The results justify the convergence and effectiveness of the algorithm. In addition, the results show that it is necessary to take the cable sags and inertias into consideration for the large-span manipulators.

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

International Nuclear Information System (INIS)

Grisel, J.; Royet, J.M.; Scanlan, R.M.; Armer, R.

1988-08-01

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

Cable networks, services, and management

CERN Document Server

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...

Development of Inspection Robots for Bridge Cables

Directory of Open Access Journals (Sweden)

Hae-Bum Yun

2013-01-01

Full Text Available This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

How do you like them cables?

CERN Multimedia

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...

Dynamical Analysis and Simulation Validation of Incompletely Restrained Cable-Suspended Swinging System Driven by Two Cables

Directory of Open Access Journals (Sweden)

Naige Wang

2016-01-01

Full Text Available The flexibility of the suspension multicables and driven length difference between two cables cause the translation and rotation of the platform in the incompletely restrained cable-suspended system driven by two cables (IRCSWs2, which are theoretically investigated in this paper. The suspension cables are spatially discretized using the assumed modes method (AMM and the equations of motion are derived from Lagrange equations of the first kind. Considering all the geometric matching conditions are approximately linear with external actuator, the differential algebraic equations (DAEs are transformed to a system of ordinary differential equations (ODEs. Using linear boundary conditions of the suspension cable, the current method can obtain not only the accurate longitudinal displacements of cable and posture of the platform, but also the tension between the platform and cables, and the current method is verified by ADAMS simulation.

Instrumentation Cables Test Plan

Energy Technology Data Exchange (ETDEWEB)

Muna, Alice Baca [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); LaFleur, Chris Bensdotter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-10-01

A fire at a nuclear power plant (NPP) has the potential to damage structures, systems, and components important to safety, if not promptly detected and suppressed. At Browns Ferry Nuclear Power Plant on March 22, 1975, a fire in the reactor building damaged electrical power and control systems. Damage to instrumentation cables impeded the function of both normal and standby reactor coolant systems, and degraded the operators’ plant monitoring capability. This event resulted in additional NRC involvement with utilities to ensure that NPPs are properly protected from fire as intended by the NRC principle design criteria (i.e., general design criteria 3, Fire Protection). Current guidance and methods for both deterministic and performance based approaches typically make conservative (bounding) assumptions regarding the fire-induced failure modes of instrumentation cables and those failure modes effects on component and system response. Numerous fire testing programs have been conducted in the past to evaluate the failure modes and effects of electrical cables exposed to severe thermal conditions. However, that testing has primarily focused on control circuits with only a limited number of tests performed on instrumentation circuits. In 2001, the Nuclear Energy Institute (NEI) and the Electric Power Research Institute (EPRI) conducted a series of cable fire tests designed to address specific aspects of the cable failure and circuit fault issues of concern1. The NRC was invited to observe and participate in that program. The NRC sponsored Sandia National Laboratories to support this participation, whom among other things, added a 4-20 mA instrumentation circuit and instrumentation cabling to six of the tests. Although limited, one insight drawn from those instrumentation circuits tests was that the failure characteristics appeared to depend on the cable insulation material. The results showed that for thermoset insulated cables, the instrument reading tended to drift

Study of the impact of board orientation on radiated emissions due to common-mode currents on attached cables

DEFF Research Database (Denmark)

Sørensen, Morten; Hubing, Todd H.; Jensen, Kim

2016-01-01

Common-mode current on attached cables is a typical source for radiated emission. Several models have been made for conversion of the intended differential signal to unwanted common-mode current on cables. In this paper we refine a method for identifying the radiation sources arising from a long...... microstrip. This method is used to show that the radiated emission from a PCB with attached cable(s) caused by a long trace depends on whether the trace is facing up or down with different result for voltage and current sources....

Geometric nonlinear analysis of self-anchored cable-stayed suspension bridges.

Science.gov (United States)

Hui-Li, Wang; Yan-Bin, Tan; Si-Feng, Qin; Zhe, Zhang

2013-01-01

Geometric nonlinearity of self-anchored cable-stayed suspension bridges is studied in this paper. The repercussion of shrinkage and creep of concrete, rise-to-span ratio, and girder camber on the system is discussed. A self-anchored cable-stayed suspension bridge with a main span of 800 m is analyzed with linear theory, second-order theory, and nonlinear theory, respectively. In the condition of various rise-to-span ratios and girder cambers, the moments and displacements of both the girder and the pylon under live load are acquired. Based on the results it is derived that the second-order theory can be adopted to analyze a self-anchored cable-stayed suspension bridge with a main span of 800 m, and the error is less than 6%. The shrinkage and creep of concrete impose a conspicuous impact on the structure. And it outmatches suspension bridges for system stiffness. As the rise-to-span ratio increases, the axial forces of the main cable and the girder decline. The system stiffness rises with the girder camber being employed.

Geometric Nonlinear Analysis of Self-Anchored Cable-Stayed Suspension Bridges

Directory of Open Access Journals (Sweden)

Wang Hui-Li

2013-01-01

Full Text Available Geometric nonlinearity of self-anchored cable-stayed suspension bridges is studied in this paper. The repercussion of shrinkage and creep of concrete, rise-to-span ratio, and girder camber on the system is discussed. A self-anchored cable-stayed suspension bridge with a main span of 800 m is analyzed with linear theory, second-order theory, and nonlinear theory, respectively. In the condition of various rise-to-span ratios and girder cambers, the moments and displacements of both the girder and the pylon under live load are acquired. Based on the results it is derived that the second-order theory can be adopted to analyze a self-anchored cable-stayed suspension bridge with a main span of 800 m, and the error is less than 6%. The shrinkage and creep of concrete impose a conspicuous impact on the structure. And it outmatches suspension bridges for system stiffness. As the rise-to-span ratio increases, the axial forces of the main cable and the girder decline. The system stiffness rises with the girder camber being employed.

14 CFR 27.1365 - Electric cables.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Electric cables. 27.1365 Section 27.1365... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Electrical Systems and Equipment § 27.1365 Electric cables. (a) Each electric connecting cable must be of adequate capacity. (b) Each cable that would overheat...

The Danish Superconducting Cable Project

DEFF Research Database (Denmark)

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...

Cable handling

International Nuclear Information System (INIS)

1980-01-01

In computerized axial tomography scanning, problems arise in exchanging electrical signals between fixed and rotating assemblies. A novel method of overcoming this problem is described in detail for both signal and high voltage cables. Apparatus using a sequence of drums and pulleys is used to maintain the interconnecting cables in a neat arrangement and free from mechanical strain. The apparatus is simple and relatively easy and inexpensive to assemble and maintain. (UK)

The RHIC transfer line cable database

International Nuclear Information System (INIS)

Scholl, E.H.; Satogata, T.

1995-01-01

A cable database was created to facilitate and document installation of cables and wiring in the RHIC project, as well as to provide a data source to track possible wiring and signal problems. The eight tables of this relational database, currently implemented in Sybase, contain information ranging from cable routing to attenuation of individual wires. This database was created in a hierarchical scheme under the assumption that cables contain wires -- each instance of a cable has one to many wires associated with it. This scheme allows entry of information pertinent to individual wires while only requiring single entries for each cable. Relationships to other RHIC databases are also discussed

Electromagnetic transients in power cables

CERN Document Server

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,

Low voltage powering of on-detector electronics for HL-LHC experiments upgrades

CERN Document Server

Bobillier, Vincent; Vasey, Francois; Karmakar, Sabyasachi; Maity, Manas; Roy, Subhasish; Kundu, Tapas Kumar

2018-01-01

All LHC experiments will be upgraded during the next LHC long shutdowns (LS2 and LS3). The increase in resolution and luminosity and the use of more advanced CMOS technology nodes typically implies higher current consumption of the on-detector electronics. In this context, and in view of limiting the cable voltage drop, point-of-load DC-DC converters will be used on detector. This will have a direct impact on the existing powering scheme, implying new AC-DC and/or DC-DC stages as well as changes in the power cabling infrastructure. This paper presents the first results obtained while evaluating different LV powering schemes and distribution layouts for HL-LHC trackers. The precise low voltage power source requirements are being assessed and understood using the CMS tracker upgrade as a use-case.

Step-Up DC-DC converters

DEFF Research Database (Denmark)

Forouzesh, Mojtaba; Siwakoti, Yam P.; Gorji, Saman A.

2017-01-01

on the general law and framework of the development of next-generation step-up dc-dc converters, this paper aims to comprehensively review and classify various step-up dc-dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage...

30 CFR 18.45 - Cable reels.

Science.gov (United States)

2010-07-01

... and locomotives shall maintain positive tension on the portable cable during reeling and unreeling. Such tension shall only be high enough to prevent a machine from running over its own cable(s). (e... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Cable reels. 18.45 Section 18.45 Mineral...

14 CFR 25.689 - Cable systems.

Science.gov (United States)

2010-01-01

... cable system must be designed so that there will be no hazardous change in cable tension throughout the... 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...

Experience from design, prototyping and production of a DC–DC conversion powering scheme for the CMS Phase-1 Pixel Upgrade

Energy Technology Data Exchange (ETDEWEB)

Feld, Lutz, E-mail: Lutz.Feld@cern.ch; Karpinski, Waclaw; Klein, Katja; Lipinski, Martin; Preuten, Marius; Rauch, Max; Schmitz, Stefan; Wlochal, Michael

2017-02-11

The CMS pixel detector will be replaced during the technical stop 2016/2017. To allow the new pixel detector to be powered with the legacy cable plant and power supplies, a novel powering scheme based on DC–DC conversion will be employed. After the successful conclusion of an extensive development and prototyping phase, mass production of 1800 DC–DC converters as well as motherboards and other power PCBs has now been completed. This contribution reviews the lessons learned from the development of the power system for the Phase-1 pixel detector, and summarizes the experience gained from the production phase.

OTEC riser cable model and prototype testing

Science.gov (United States)

Kurt, J. P.; Schultz, J. A.; Roblee, L. H. S.

1981-12-01

Two different OTEC riser cables have been developed to span the distance between a floating OTEC power plant and the ocean floor. The major design concerns for a riser cable in the dynamic OTEC environment are fatigue, corrosion, and electrical/mechanical aging of the cable components. The basic properties of the cable materials were studied through tests on model cables and on samples of cable materials. Full-scale prototype cables were manufactured and were tested to measure their electrical and mechanical properties and performance. The full-scale testing was culminated by the electrical/mechanical fatigue test, which exposes full-scale cables to simultaneous tension, bending and electrical loads, all in a natural seawater environment.

Lightning-resistant, low-inductance detonator cables

Energy Technology Data Exchange (ETDEWEB)

Druce, R.L.; Lee, R.S.; Moua, K.

1994-04-01

A lightning strike on a flat detonator cable in close proximity to a high explosive (HE) main charge poses a possible detonation hazard if the electrical explosion of the cable launches the dielectric cover coat of the cable at a high enough velocity to shock-initiate the HE. The detonator cable for the W87 system has been demonstrated to be incapable of initiating LX-17 main-charge explosive even for a 99 percentile negative lightning strike (1). The W87 cable is a relatively high inductance cable, unsuitable for use with low-inductance firesets. We have performed tests on a low-inductance cable designed for the W89 program, which show it to be marginal in its ability to withstand a lightning strike without the possibility of initiating a heated LX-17 main charge HE. A new cable design, proposed by R.E. Lee of LLNL has been tested and shown to be capable of withstanding a 99 percentile negative lightning strike without initiating LX-17 heated to 250{degree}C.

Aerodynamics of the cable of cable-stayed bridges; Shachokyo cable no kuriki shindo tokusei no rikai to soreni motozuku kuriki seishinho no teian

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, M. [Kyoto University, Kyoto (Japan). Faculty of Engineering; Aoki, J.; Fuji, D. [West Japan Railway Company, Osaka (Japan); Kitayama, N. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan); Daito, Y. [Kyoto University, Kyoto (Japan)

1996-07-21

Wind tunnel tests were conducted assuming the aerodynamics of the cable of cable-stayed bridges especially in the case of strong wind with rain. Based on the results, an aerodynamic damping method was proposed. Factors of the rain vibration generation include the three-dimensional axial flow behind the cable, which is formed by the wind direction deviation angle, the upper side water flow on the cable surface formed by the rain, and the Karman vortex shedding, which are not uniform in the span direction. Newly proposed cable with elliptical plates showed an effective dumping performance. It restrains the formation of water flow due to its profile, and is effective for unstableness due to water flow formation. Distribution of the axial flow in the cable span direction was made clear. Three-dimensionality of the vortex shedding was greatly affected by this axial flow. Frequency of the Karman vortex shedding changed in the wide band by the axial flow. It was suggested that three-dimensionality of the flow field is enhanced by the rolling vibration, resulting in the unstableness of heaving vibration. 5 refs., 15 figs.

Composite carbon fiber cables; Des cables composites en fibres de carbone

Energy Technology Data Exchange (ETDEWEB)

Anon.

2002-10-01

In order to fulfill the requirements of offshore engineering, Freyssinet, a daughter company of the European Vinci group, has developed a series of high-performance carbon fiber cables. These composite materials have an excellent fatigue behaviour in a huge range of constraints. Moreover, their low weight allows the implementation of very long lengths of cables in marine environment with no loss in capacity. The specific weight of the current part of the cable is reduced by a factor of 4 with respect to an equivalent capacity armature made of steel. These materials were presented in June 2002 at the ultra deep engineering and technologies (UDET) exhibition of Brest (France). (J.S.)

Current distribution inside Rutherford-type superconducting cables and impact on performance of LHC dipoles

CERN Document Server

Schreiner, T

2002-01-01

The windings of high--field superconducting accelerator magnets are usually made of Rutherford--type cables. The magnetic field distribution along the axis of such magnets exhibits a periodic modulation with a wavelength equal to the twist pitch length of the cable used in the winding. Such a Periodic Field Pattern (PFP) has already been observed in number of superconducting accelerator magnets. Additional unbalanced currents in individual strands of the cable appear to be causing this effect. The present thesis describes the investigation of the PFPs performed with a Hall probes array inserted inside the aperture of the LHC superconducting dipoles, both in the small--scale model magnets with a length of one meter and in full--scale prototypes and pre--series magnets with fifteen meters of length. The amplitude and the time dependence of this periodic field oscillation have been studied as a function of the magnet current history. One of the main parameters influencing the properties of the PFP is the cross--...

Understanding losses in three core armoured submarine cables

DEFF Research Database (Denmark)

Silva, Filipe Miguel Faria da; Ebdrup, Thomas; Bak, Claus Leth

2016-01-01

. For practical an economical reasons the preferred choice of cable for both the array and the transmission cables are three-core armoured submarine cables. Therefore, it has becoming increasingly important to be able to calculate the ampacity of such cables accurately. At present time, the ampacity of three......-core armoured submarine cables is calculated according to IEC 60287-1-1 [1]. Various measurements conducted both by cable manufacturers and transmission system operators (TSO) have shown that using the cable rating method stated in IEC 60287-1-1 underestimates the cable ampacity [2]-[6]. Furthermore......, measurements conducted within the cable industry have shown that an armoured three core cable has higher losses than equal unarmoured three core cables. It is also suggested that the inaccuracy in the IEC armour’s loss factor (λ2) is the main responsible for the conservatism in the IEC cable rating method...

Cable Bacteria in Freshwater Sediments

DEFF Research Database (Denmark)

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...... 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...

Length of a Hanging Cable

Directory of Open Access Journals (Sweden)

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.

Long-term test of the 22.9kV HTS power cable system in LS Cable Ltd

International Nuclear Information System (INIS)

Jang, Hyun Man; Lee, Chang Young; Kim, Choon Dong; Kim, Do Hyung; Park, In Son; Ji, Bong Ki; Kim, Dong Wook; Cho, Jeonwook

2006-01-01

Since 2001, LS cable Ltd. has been developing the design, manufacturing and evaluation technologies for high temperature superconducting (HTS) power cable system as a member of DAPAS (Dream for Advanced Power system by Applied Superconductivity technology) program in Korea. The 30 m HTS cable system that is rated at 22.9 kV and 1.2 kA giving a rated capacity of 50 MVA had been developed and tested. The cable was designed as a cold dielectric type employing Bi-2223 HTS tapes and polypropylene (PP) laminated paper as the conductor and electrical insulation, respectively. The cable is cooled with sub-cooled liquid nitrogen at temperature from 75 to 77 K. The manufacturing and the installation of the cable system were completed in 2004. Long-term performance test of the cable system has been conducted for six months to verify its electric and mechanical properties in 2005

Bulk Electrical Cable Non-Destructive Examination Methods for Nuclear Power Plant Cable Aging Management Programs

Energy Technology Data Exchange (ETDEWEB)

Glass, Samuel W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jones, Anthony M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hartman, Trenton S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-09-01

This Pacific Northwest National Laboratory milestone report describes progress to date on the investigation of nondestructive test methods focusing particularly on bulk electrical test methods that provide key indicators of cable aging and damage. The work includes a review of relevant literature as well as hands-on experimental verification of inspection capabilities. As nuclear power plants consider applying for second, or subsequent, license renewal to extend their operating period from 60 years to 80 years, it is important to understand how the materials installed in plant systems and components will age during that time and develop aging management programs to assure continued safe operation under normal and design basis events (DBE). Normal component and system tests typically confirm the cables can perform their normal operational function. The focus of the cable test program, however, is directed toward the more demanding challenge of assuring the cable function under accident or DBE. The industry has adopted 50% elongation at break (EAB) relative to the un-aged cable condition as the acceptability standard. All tests are benchmarked against the cable EAB test. EAB, however, is a destructive test so the test programs must apply an array of other nondestructive examination (NDE) tests to assure or infer the overall set of cable’s system integrity. Assessment of cable integrity is further complicated in many cases by vendor’s use of dissimilar material for jacket and insulation. Frequently the jacket will degrade more rapidly than the underlying insulation. Although this can serve as an early alert to cable damage, direct test of the cable insulation without violating the protective jacket becomes problematic. This report addresses the range of bulk electrical NDE cable tests that are or could be practically implemented in a field-test situation with a particular focus on frequency domain reflectometry (FDR). The FDR test method offers numerous advantages

75 FR 23571 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

Science.gov (United States)

2010-05-04

... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10... amends Sec. 39.13 by adding the following new AD: 2010-09-12 McDonnell Douglas Corporation: Amendment 39... to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A...

Self-healing cable for extreme environments

Science.gov (United States)

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.

Analytical and numerical construction of equivalent cables.

Science.gov (United States)

Lindsay, K A; Rosenberg, J R; Tucker, G

2003-08-01

The mathematical complexity experienced when applying cable theory to arbitrarily branched dendrites has lead to the development of a simple representation of any branched dendrite called the equivalent cable. The equivalent cable is an unbranched model of a dendrite and a one-to-one mapping of potentials and currents on the branched model to those on the unbranched model, and vice versa. The piecewise uniform cable, with a symmetrised tri-diagonal system matrix, is shown to represent the canonical form for an equivalent cable. Through a novel application of the Laplace transform it is demonstrated that an arbitrary branched model of a dendrite can be transformed to the canonical form of an equivalent cable. The characteristic properties of the equivalent cable are extracted from the matrix for the transformed branched model. The one-to-one mapping follows automatically from the construction of the equivalent cable. The equivalent cable is used to provide a new procedure for characterising the location of synaptic contacts on spinal interneurons.

Long-distance electron transport by cable bacteria in mangrove sediments

NARCIS (Netherlands)

Burdorf, L.D.; Hidalgo-Martinez, S.; Cook, P.L.M.C.; Meysman, F.

2016-01-01

Cable bacteria are long, filamentoussulphur-oxidizing bacteria that induce long-distanceelectron transport in aquatic sediments. They turnthe seafloor into an electro-active environment, characterizedby currents and electrical fields, and whenpresent, they exert a strong impact on the

Superconducting flat tape cable magnet

Science.gov (United States)

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.

Superconducting coil manufacturing method for low current dc beam line magnets

International Nuclear Information System (INIS)

Satti, J.A.

1977-01-01

A method of manufacturing superconducting multipole coils for 40 to 50 kG dc beam line magnets with low current is described. Small coils were built and tested successfully to short sample characteristics. The coils did not train after the first cooldown. The coils are porous and well cooled to cope with mechanical instability and energy deposited in the coil from the beam particles. The coils are wound with insulated strand cable. The cable is shaped rectangularly for winding simplicity and good tolerances. After the coil is wound, the insulated strands are electrically connected in series. This reduces the operating current and, most important, improves the coil quench propagation due to heat conduction of one strand adjacent to the other. A well distributed quench allows the magnet energy to distribute more uniformly to the copper in the superconductor wire, giving self-protected coils. A one-meter long, 43 kG, 6-inch bore tube superconducting dipole is now being fabricated. The porous coil design and coil winding methods are discussed

47 CFR 27.1202 - Cable/BRS cross-ownership.

Science.gov (United States)

2010-10-01

... portion of the franchise area actually served by the cable operator's cable system and the cable operator... franchise area actually served by the cable operator's cable system the cable operator will use the BRS... that no portion of the GSA of the BRS station is within the portion of the franchise area actually...

Hall probe magnetometer for SSC magnet cables

International Nuclear Information System (INIS)

Cross, R.W.; Goldfarb, R.B.

1991-01-01

The authors of this paper constructed a Hall probe magnetometer to measure the magnetization hysteresis loops of Superconducting Super Collider magnet cables. The instrument uses two Hall-effect field sensors to measure the applied field H and the magnetic induction B. Magnetization M is calculated from the difference of the two quantities. The Hall probes are centered coaxially in the bore of a superconducting solenoid with the B probe against the sample's broad surface. An alternative probe arrangement, in which M is measured directly, aligns the sample probe parallel to the field. The authors measured M as a function of H and field cycle rate both with and without a dc transport current. Flux creep as a function of current was measured from the dependence of ac loss on the cycling rate and from the decay of magnetization with time. Transport currents up to 20% of the critical current have minimal effect on magnetization and flux creep

High voltage performance of a dc photoemission electron gun with centrifugal barrel-polished electrodes

Science.gov (United States)

Hernandez-Garcia, C.; Bullard, D.; Hannon, F.; Wang, Y.; Poelker, M.

2017-09-01

The design and fabrication of electrodes for direct current (dc) high voltage photoemission electron guns can significantly influence their performance, most notably in terms of maximum achievable bias voltage. Proper electrostatic design of the triple-point junction shield electrode minimizes the risk of electrical breakdown (arcing) along the insulator-cable plug interface, while the electrode shape is designed to maintain work, we describe a centrifugal barrel-polishing technique commonly used for polishing the interior surface of superconducting radio frequency cavities but implemented here for the first time to polish electrodes for dc high voltage photoguns. The technique reduced polishing time from weeks to hours while providing surface roughness comparable to that obtained with diamond-paste polishing and with unprecedented consistency between different electrode samples. We present electrode design considerations and high voltage conditioning results to 360 kV (˜11 MV/m), comparing barrel-polished electrode performance to that of diamond-paste polished electrodes. Tests were performed using a dc high voltage photogun with an inverted-geometry ceramic insulator design.

DC Home Appliances for DC Distribution System

Directory of Open Access Journals (Sweden)

MUHAMMAD KAMRAN

2017-10-01

Full Text Available This paper strengthens the idea of DC distribution system for DC microgrid consisting of a building of 50 apartments. Since the war of currents AC system has been dominant because of the paucity of research in the protection of the DC system. Now with the advance research in power electronics material and components, generation of electricity is inherently DC as by solar PV, fuel cell and thermoelectric generator that eliminates the rectification process. Transformers are replaced by the power electronics buck-boost converters. DC circuit breakers have solved the protection problems for both DC transmission and distribution system. In this paper 308V DC microgrid is proposed and home appliances (DC internal are modified to operate on 48V DC from DC distribution line. Instead of using universal and induction motors in rotary appliances, BLDC (Brushless DC motors are proposed that are highly efficient with minimum electro-mechanical and no commutation losses. Proposed DC system reduces the power conversion stages, hence diminishes the associated power losses and standby losses that boost the overall system efficiency. So in view of all this a conventional AC system can be replaced by a DC system that has many advantages by cost as well as by performance

Family of multiport bidirectional DC-DC converters

NARCIS (Netherlands)

Tao, H.; Kotsopoulos, A.; Duarte, J.L.; Hendrix, M.A.M.

2006-01-01

Multiport DC-DC converters are of potential interest in applications such as generation systems utilising multiple sustainable energy sources. A family of multiport bidirectional DC-DC converters derived from a general topology is presented. The topology shows a combination of DC-link and magnetic

The analysis of cable forces based on natural frequency

Science.gov (United States)

Suangga, Made; Hidayat, Irpan; Juliastuti; Bontan, Darwin Julius

2017-12-01

A cable is a flexible structural member that is effective at resisting tensile forces. Cables are used in a variety of structures that employ their unique characteristics to create efficient design tension members. The condition of the cable forces in the cable supported structure is an important indication of judging whether the structure is in good condition. Several methods have been developed to measure on site cable forces. Vibration technique using correlation between natural frequency and cable forces is a simple method to determine in situ cable forces, however the method need accurate information on the boundary condition, cable mass, and cable length. The natural frequency of the cable is determined using FFT (Fast Fourier Transform) Technique to the acceleration record of the cable. Based on the natural frequency obtained, the cable forces then can be determine by analytical or by finite element program. This research is focus on the vibration techniques to determine the cable forces, to understand the physical parameter effect of the cable and also modelling techniques to the natural frequency and cable forces.

Aluminium cables in automotive applications : Prestudy of aluminium cable uses in Scania products&Failure analysis and evaluation

OpenAIRE

Man, Yu

2016-01-01

The increasing demand of light constructed vehicles as well as soaring price of copper metal owing to limited nature resources have been promoting the use of aluminium metal as an alternative conductor of automotive cables. This thesis work is to lay theoretical foundations for further research and development regarding the introduction of new automotive cables i.e. aluminium cables. Current application of automotive aluminium cables in automotive industry as well as failure analysis and eval...

MEDOW - Multi-terminal DC Grid for Offshore Wind, Final report

DEFF Research Database (Denmark)

A DC grid based on multi-terminal voltage-source converter is a newly emerging technology, which is particularly suitable for the connection of offshore wind farms. Multi-terminal DC grids will be the key technology for the European offshore ‘Super Grid’. In the project, DC power flow, DC relaying...... protection, steady state operation, dynamic stability, fault-ride through capability, and impacts of DC grids on the operation of AC grids and power market were studied. Systematic comparison of DC grid topologies and stability control strategies was carried out, and DC grids for offshore wind power...

Initial tension loss in cerclage cables.

Science.gov (United States)

Ménard, Jérémie; Émard, Maxime; Canet, Fanny; Brailovski, Vladimir; Petit, Yvan; Laflamme, George Y

2013-10-01

Cerclage cables, frequently used in the management of fractures and osteotomies, are associated with a high failure rate and significant loosening during surgery. This study compared the capacity to maintain tension of different types of orthopaedic cable systems. Multifilament Cobalt-Chrome (CoCr) cables with four different crimp/clamp devices (DePuy, Stryker, Zimmer and Smith&Nephew) and one non-metallic Nylon (Ny) cable from Kinamed were instrumented with a load cell to measure tension during insertion. Significant tension loss was observed with crimping for all cables (Ptensioner led to an additional unexpected tension loss (CoCr-DePuy: 18%, CoCr-Stryker: 29%, CoCr-Smith&Nephew: 33%, Ny: 46%, and CoCr-Zimmer: 52%). The simple CoCr (DePuy) cable system outperformed the more sophisticated locking devices due to its significantly better ability to prevent tension loss. Copyright © 2013 Elsevier Inc. All rights reserved.

Power cables now and in the future

Energy Technology Data Exchange (ETDEWEB)

Wanser, G

1976-01-01

A survey is presented of the problems to be faced with the underground supply of electric power to large, urban areas and of the contributions that improvements in power cable technology will make to solving these problems. It is concluded that the increase in population densities and the rising demand for energy on the part of individual consumers bring up problems for electricity supply and thus have a direct influence on development trends in cable engineering. During the last few years the increasing capacities required in power transmission have led to the use of higher voltages and to the application of special methods of cooling for the oil-filled cable. When the technical and economic possibilities with present-day cable techniques have been exhausted, we must anticipate the introduction of new types of cable, i.e., gas-insulated cables and superconducting cables. The problems involved in power distribution are being solved successfully by resorting to larger conductor cross-sectional areas and by raising the voltage levels. The advantages of plastic cables are also being utilized on a wide scale. The requirement that there be freedom from partial discharges in plastic cables operating at medium and higher voltages is becoming increasingly more widely adopted as a new quality criterion in cable engineering. New materials from the polymer range are permitting the introduction of fittings which are easier to install and which reduce costs. Cable engineering has already, to a considerable extent, adapted itself to face future problems. Even so, there are still a large number of problems in cable engineering requiring research, development and operation.

High-voltage polymeric insulated cables

Energy Technology Data Exchange (ETDEWEB)

Ross, A

1987-01-01

Reviews developments in high-voltage (here defined as 25 kV, 66 kV and 132 kV) polymeric insulated cables in the UK over the period 1979-1986, with particular reference to the experience of the Eastern Electricity Board. Outlines the background to the adoption of XPLE-insulated solid cable, and the design, testing, terminations, jointing and costs of 25 kV, 66 kV and 132 kV cables.

Offshore Cable Installation - Lillgrund. Lillgrund Pilot Project

Energy Technology Data Exchange (ETDEWEB)

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

Noise propagation issues in Belle II pixel detector power cable

Science.gov (United States)

Iglesias, M.; Arteche, F.; Echeverria, I.; Pradas, A.; Rivetta, C.; Moser, H.-G.; Kiesling, C.; Rummel, S.; Arcega, F. J.

2018-04-01

The vertex detector used in the upgrade of High-Energy physics experiment Belle II includes DEPFET pixel detector (PXD) technology. In this complex topology the power supply units and the front-end electronics are connected through a PXD power cable bundle which may propagate the output noise from the power supplies to the vertex area. This paper presents a study of the propagation of noise caused by power converters in the PXD cable bundle based on Multi-conductor Transmission Line (MTL) theory. The work exposes the effect of the complex cable topology and shield connections on the noise propagation, which has an impact on the requirements of the power supplies. This analysis is part of the electromagnetic compatibility based design focused on functional safety to define the shield connections and power supply specifications required to ensure the successful integration of the detector and, specifically, to achieve the designed performance of the front-end electronics.

Study of special spacer with damping device for suppressing wake galloping in tandem cables of cable-stayed bridges and its application to full scale bridge; Nendanseitai wo riyoshita heiretsu cable yo gensui kinotsuki spacer to sono jikkyo cable eno tekiyo ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Yoneda, M.; Setouchi, H.; Yoshioka, A. [Kawada Industries Inc., Tokyo (Japan); Shimoda, I.; Kawahara, S. [Oiles Corp., Tokyo (Japan)

1996-12-20

Cable vibration called wake galloping occurs in a cable-stayed bridge, in which cables are arranged tandem, and suppression of the vibration is an extremely important discussion item. This paper describes a complex eigen value analysis performed on tandem cables having lengths of 200 m and 100 m. The analysis revealed that damping characteristics added by a spacer system with a damping device (a type to install a visco-elastic body at about middle of the tandem cables via a jig) depend largely on torsional rigidity of the cables; and the characteristics may vary with difference in intervals between cable centers and that in cable diameters. A visco-elastic damping material of an asphalt system and a spacer with a damping device used as a spring material were fabricated and applied to a full scale bridge to identify quantitatively the damping addition characteristics of this system. Furthermore, the results of tests on the full scale bridge were compared with the result of the complex eigen value analysis, from which findings useful for actual works were obtained. 18 refs., 17 figs., 6 tabs.

Cable Television Report and Suggested Ordinance.

Science.gov (United States)

League of California Cities, Sacramento.

Guidelines and suggested ordinances for cable television regulation by local governments are comprehensively discussed in this report. The emphasis is placed on franchising the cable operator. Seventeen legal aspects of franchising are reviewed, and an exemplary ordinance is presented. In addition, current statistics about cable franchising in…

Effect of Concrete Creep on the displacement of single tower single cable plane Extradosed Cable-stayed Bridge

Science.gov (United States)

Shi, Jing-xian; Ran, Zhi-hong

2018-03-01

Extradossed Cable-stayed Bridge is both cable-stayed Bridge and Continuous rigid frame bridge mechanics feature, Beam is the main force components, cable is supplement.This article combined with a single tower and single cable plane Extradossed cable-stayed bridge in Yunnan, use different creep calculation models and analysis deflection caused by creep effects. The results showing that deflection caused by creep effect is smaller than the same span continuous rigid frame bridge, the value is about 2cm. On the other hand the deflection is increasing with ambient humidity decreases, therefore in the dry environment the calculation model is relatively large in the pre-camber. In the choice of RC creep model is significant in the dry areas.

Cable indenter aging monitor

International Nuclear Information System (INIS)

Shook, T.A.; Gardner, J.B.

1988-07-01

This project was undertaken to develop a hand-held, nondestructive test device to assess the aged condition of electrical cable by in situ measurement of mechanical properties of polymeric jackets and insulations. The device is an indenter similar to those used to make hardness measurements. Comparison of measurements made on installed cables with previous measurements serving as baseline aging/mechanical property data will determine the state of aging of the field cables. Such a device will be valuable in nuclear and fossil plant life extension programs. Preliminary laboratory tests on cables covered with ethylene propylene rubber (EPR) and chlorosulfated polyethylene (CSPE) point to the measurement of the rate of force increase resulting from constant rate deformation as having the best correlation with progressive thermal aging. This first phase of the work has demonstrated the technical feasibility of the method. A second phase will include the generation of additional groundwork data and the design of the portable indenter for in situ plant measurements

46 CFR 111.60-5 - Cable installation.

Science.gov (United States)

2010-10-01

... REQUIREMENTS Wiring Materials and Methods § 111.60-5 Cable installation. (a) Each cable installation must meet... 46 Shipping 4 2010-10-01 2010-10-01 false Cable installation. 111.60-5 Section 111.60-5 Shipping... incorporated by reference; see 46 CFR 110.10-1), including clause 8. (b) Each cable installation made in...

Optical Measurement of Cable and String Vibration

Directory of Open Access Journals (Sweden)

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.

Simple Program to Investigate Hysteresis Damping Effect of Cross-Ties on Cables Vibration of Cable-Stayed Bridges

Directory of Open Access Journals (Sweden)

Panagis G. Papadopoulos

2012-01-01

Full Text Available A short computer program, fully documented, is presented, for the step-by-step dynamic analysis of isolated cables or couples of parallel cables of a cable-stayed bridge, connected to each other and possibly with the deck of the bridge, by very thin pretensioned wires (cross-ties and subjected to variation of their axial forces due to traffic or to successive pulses of a wind drag force. A simplified SDOF model, approximating the fundamental vibration mode, is adopted for every individual cable. The geometric nonlinearity of the cables is taken into account by their geometric stiffness, whereas the material nonlinearities of the cross-ties include compressive loosening, tensile yielding, and hysteresis stress-strain loops. Seven numerical experiments are performed. Based on them, it is observed that if two interconnected parallel cables have different dynamic characteristics, for example different lengths, thus different masses, weights, and geometric stiffnesses, too, or if one of them has a small additional mass, then a single pretensioned very thin wire, connecting them to each other and possibly with the deck of the bridge, proves effective in suppressing, by its hysteresis damping, the vibrations of the cables.

Final Report: MATERIALS, STRANDS, AND CABLES FOR SUPERCONDUCTING ACCELERATOR MAGNETS [Grant Number DE-SC0010312

Energy Technology Data Exchange (ETDEWEB)

Sumption, Mike D. [The Ohio State Univ., Columbus, OH (United States). Center for Superconducting and Magnetic Materials (CSMM); Collings, Edward W. [The Ohio State Univ., Columbus, OH (United States). Center for Superconducting and Magnetic Materials (CSMM)

2014-10-29

Our program consisted of the two components: Strand Research and Cable Research, with a focus on Nb3Sn, Bi2212, and YBCO for accelerator magnet applications. We demonstrated a method to refine the grains in Nb3Sn by a factor of two, reaching 45 nm grain sizes, and layer Jcs of 6 kA/mm2 at 12 T. W also measured conductor magnetization for field quality. This has been done both with Nb3Sn conductor, as well as Bi:2212 strand. Work in support of quench studies of YBCO coils was also performed. Cable loss studies in Nb3Sn focused on connecting and comparing persistent magnetization and coupling magnetization for considering their relative impact on HEP machines. In the area of HTS cables, we have investigated both the quench in multistrand YBCO CORC cables, as well as the magnetization of these cables for use in high field magnets. In addition, we examined the magnetic and thermal properties of large (50 T) solenoids.

Design and Testing of Boost Type DC/DC Converter for DC Motor Control Applications

OpenAIRE

Samman, Faizal Arya; Akil, Yusri Syam; Noor, Nirwan A.

2017-01-01

in The Proceeding of The 2nd International Symposium on Smart Material and Mechatronics 2015 This paper presents the design and testing of a boost type DC/DC converter circuit, which can be used for DC motor control applications. The Boost converter is designed using DC chopper and DC chopper cascade configurations. The experimental setup was made by connecting the boost converter circuit with four types of DC motor, i.e. self-excited DC motor shunt, series, compound and separately exci...

Fatigue of cable anchorage of large cable stayed bridge; Daikibo shachokyo cable teichaku kozo no hiro

Energy Technology Data Exchange (ETDEWEB)

Endo, T.; Matsumoto, T. [Honshu-Shikoku Bridge Authority, Tokyo (Japan); Tsukahara, H. [Yokogawa Bridge Corp., Tokyo (Japan); Miki, C. [Tokyo Institute of Technology, Tokyo (Japan)

1995-10-21

Design considerations such as design schemes, the assemblage and welding of steel plates, and safety for fatigue of welded connections have to be taken for the cable anchorages of the steel cable stayed bridges. In this study, two full scale models, which have different shape of box anchorages welded to the web of the main girder, were made to investigate fatigue characteristics as well as assemblage of plate and gelding details. Finite element analyses for both test models and actual bridges here carried out to compare stress distribution. It was confirmed that the assemblage and welding of both types of box anchorage were attainable kith required quality and accuracy. According to the fatigue test, fatigue cracks originated from the weldings of the bearing plate to which the load from cable socket applied directly were caused by out-of-plane bending of the bearing plate. It was proved that the slight modifications of the details around the bearing plate resulted in sufficient fatigue strength in both types of anchorage. 1 ref., 23 figs., 2 tabs.

Cable SGEMP Code Validation Study

Energy Technology Data Exchange (ETDEWEB)

Ballard, William Parker [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Center for CA Weapons Systems Engineering

2013-05-01

This report compared data taken on the Modular Bremsstrahlung Simulator using copper jacketed (cujac) cables with calculations using the RHSD-RA Cable SGEMP analysis tool. The tool relies on CEPXS/ONBFP to perform radiation transport in a series of 1D slices through the cable, and then uses a Green function technique to evaluate the expected current drive on the center conductor. The data were obtained in 2003 as part of a Cabana verification and validation experiment using 1-D geometries, but were not evaluated until now. The agreement between data and model is not adequate unless gaps between the dielectric and outer conductor (ground) are assumed, and these gaps are large compared with what is believed to be in the actual cable.

Thermo-Mechanical Behavior and Shakedown of Shape Memory Alloy Cable Structures

Science.gov (United States)

Biggs, Daniel B.

Shape memory alloys (SMAs) are a versatile class of smart materials that exhibit adaptive properties which have been applied to solve engineering problems in wide-ranging fields from aerospace to biomedical engineering. Yet there is a lack of understanding of the fundamental nature of SMAs in order to effectively apply them to challenging problems within these engineering fields. Stranding fine NiTi wires into a cable form satisfies the demands of many aerospace and civil engineering applications which require actuators to withstand large tensile loads. The impact of increased bending and twisting in stranded NiTi wire structures, as well as introducing contact mechanics to the unstable phase transformation is not well understood, and this work aims to fill that void. To study the scalability of NiTi cables, thermo-mechanical characterization tests are conducted on cables much larger than those previously tested. These cables are found to have good superelastic properties and repeatable cyclic behavior with minimal induced plasticity. The behavior of additional cables, which have higher transition temperatures that can be used in a shape memory mode as thermo-responsive, high force actuator elements, are explored. These cables are found to scale up the performance of straight wire by maintaining an equivalent work output. Moreover, this work investigates the degradation of the thermal actuation of SMA wires through novel stress-temperature paths, discovering several path dependent behaviors of transformation-induced plasticity. The local mechanics of NiTi cable structures are explored through experiments utilizing digital image correlation, revealing new periodic transformation instabilities. Finite element simulations are presented, which indicate that the instabilities are caused by friction and relative sliding between wires in a cable. Finally, a study of the convective heat transfer of helical wire involving a suite of wind tunnel experiments, numerical

Five-Level Active-Neutral-Point-Clamped DC/DC Converter for Medium-Voltage DC Grids

DEFF Research Database (Denmark)

Liu, Dong; Deng, Fujin; Chen, Zhe

2017-01-01

This paper proposes a five-level active-neutralpoint- clamped (5L-ANPC) dc/dc converter for applications in medium voltage dc (MVDC) grids. A modulation strategy is proposed for the 5L-ANPC dc/dc converter to generate multilevel voltage waveforms, which can effectively reduce voltage change rate dv...... effectively eliminate high voltage leaps caused by the dead time effect. In addition, a capacitor voltage control strategy is proposed for the 5L-ANPC dc/dc converter to ensure the balanced flying capacitor voltage and desired five-level voltage waveforms. Finally, simulation and experimental studies...

Ship nuclear power device of cable aging management

International Nuclear Information System (INIS)

Wei Hua; Chen Miao; Chen Tao

2012-01-01

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)

10BASE5 Ethernet Cable & Vampire Tap

CERN Document Server

1983-01-01

10BASE5 Thick Ethernet Cable, 10Mbit/sec. In the 1980s and early 1990's, Ethernet became more popular and provided a much faster data transmission rate. This cable is one of the first ethernet cables from 1983, a thick, bulky affair. Computers were attached via "Vampire Taps" which were connectors screwed straight through the shielding of the cable.

Active optical cable for intrasatellite communications

Science.gov (United States)

Blasco, J.; Cano, D.; Navasquillo, O.; Esteban, M. A.

2017-11-01

DAS Photonics and Airbus Defence and Space (Spain) have been working for more than six years in the concept of an Active Optical Cable (AOC) for copper cable substitution. The main advantages that AOC offers are significant mass and size saving, better flexibility and routing of the cable and immunity to EMI.

DC-DC Converter Topology Assessment for Large Scale Distributed Photovoltaic Plant Architectures

Energy Technology Data Exchange (ETDEWEB)

Agamy, Mohammed S; Harfman-Todorovic, Maja; Elasser, Ahmed; Sabate, Juan A; Steigerwald, Robert L; Jiang, Yan; Essakiappan, Somasundaram

2011-07-01

Distributed photovoltaic (PV) plant architectures are emerging as a replacement for the classical central inverter based systems. However, power converters of smaller ratings may have a negative impact on system efficiency, reliability and cost. Therefore, it is necessary to design converters with very high efficiency and simpler topologies in order not to offset the benefits gained by using distributed PV systems. In this paper an evaluation of the selection criteria for dc-dc converters for distributed PV systems is performed; this evaluation includes efficiency, simplicity of design, reliability and cost. Based on this evaluation, recommendations can be made as to which class of converters is best fit for this application.

Control of improved full-bridge three-level DC/DC converter for wind turbines in a DC grid

DEFF Research Database (Denmark)

Deng, Fujin; Chen, Zhe

2013-01-01

transformer in the IFBTL dc/dc converter. A modulation strategy, including two operation modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the control of the wind turbine based on the IFBTL dc/dc converter......This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency...

Parallel monostrand stay cable bending fatigue

DEFF Research Database (Denmark)

Winkler, Jan Pawel

This dissertation investigates the bending fatigue response of high-strength steel monostrands and multistrand stay cables to cyclic transverse deformations. Increasing bridge stock numbers and a push for longer cable-supported span lengths have led to an increased number of reported incidents...... of damage and replacement of bridge stay cables due to wind and traffic-induced fatigue. The understanding of fatigue mechanisms in most steel structures is well established. However, in the case of cables composed of steel strands, many important aspects related with bending fatigue remain to be clarified...... associated with variable loading, and different testing procedures. As most of the contemporary stay cables are comprised of a number of individual highstrength steel monostrands, the research study started with an extensive experimental work on the fatigue response of a single monostrand to cyclic flexural...

IGBT Based DC/DC Converter

Directory of Open Access Journals (Sweden)

M. Akherraz

1997-12-01

Full Text Available This paper presents an in-depth analytical and experimental investigation of an indirect DC-DC converter. The DC-AC conversion is a full bridge based on IGBT power modules, and the AC-DC conversion is done via a high  frequency AC link and a first diode bridge. The AC link, which consists of snubbing capacitors and a variable air-gap transformer, is analytically designed to fulfill Zero Voltage commutation requirement. The proposed converter is simulated using PSPICE and a prototype is designed built and tested in the laboratory. PSPICE simulation and experimental results are presented and compared.

Capacitor discharge process for welding braided cable

Science.gov (United States)

Wilson, Rick D.

1995-01-01

A capacitor discharge process for welding a braided cable formed from a plurality of individual cable strands to a solid metallic electrically conductive member comprises the steps of: (a) preparing the electrically conductive member for welding by bevelling one of its end portions while leaving an ignition projection extending outwardly from the apex of the bevel; (b) clamping the electrically conductive member in a cathode fixture; (c) connecting the electrically conductive member clamped in the cathode fixture to a capacitor bank capable of being charged to a preselected voltage value; (d) preparing the braided cable for welding by wrapping one of its end portions with a metallic sheet to form a retaining ring operable to maintain the individual strands of the braided cable in fixed position within the retaining ring; (e) clamping the braided cable and the retaining ring as a unit in an anode fixture so that the wrapped end portion of the braided cable faces the ignition projection of the electrically conductive member; and (f) moving the cathode fixture towards the anode fixture until the ignition projection of the electrically conductive member contacts the end portion of the braided cable thereby allowing the capacitor bank to discharge through the electrically conductive member and through the braided cable and causing the electrically conductive member to be welded to the braided cable via capacitor discharge action.

Three-port DC-DC converter with new integrated transformer for DC Distribution Systems

DEFF Research Database (Denmark)

Ouyang, Ziwei; Andersen, Michael A. E.

2014-01-01

A new integrated transformer for three-port dc-dc converter is proposed to overcome the power coupling effect existed in some known multiple inputs dc-dc converters. Orthogonal primary windings arrangement and in series connection of diagonal secondary Windings enables a fully power decoupling...

Physical degradation assessment of generator station cables

International Nuclear Information System (INIS)

Stonkus, D.J.

1988-01-01

Preliminary studies of fossil-fired and nuclear generator station cables indicate that the low voltage PVC insulated cables are in relatively good condition. The insulation is flexible and in the case of nuclear cables can withstand a design basis event after nearly 15 years of service. Cables insulated with styrene butadiene rubber have been found embrittled and cables insulated with SBR should be closely inspected in any plant assurance program. Thermal analysis using oxidative induction technique shows promise to indicate cable insulation degradation. Long term reliability assurance and plant life extension studies are being actively pursued at Ontario Hydro. A major study is currently underway to extend the life of the oldest operating fossil-fuel station, the 8-unit, 2400 MW Lakeview TGS in operation since the 1960s. Plant life assurance programs have been initiated at the 2000 MW Lambton TGS in operation since 1969, and for the oldest operating nuclear plant, Pickering NGS A in operation since the early 1970s. As cables are considered one of the critical components in a generator station due to the extreme difficulty and cost of cable replacement, test programs have been initiated to evaluate the physical degradation of the cables and relate the results to electrical diagnostic tests and to chemical changes. The decommissioning of two small nuclear stations, the 20 MW Nuclear Power Demonstration (NPD) and the 200 MW Douglas Point NGS, which were placed in service in 1962 and 1967 respectively, will provide an opportunity to perform destructive electrical and physical evaluation on field aged cables

Three new DC-to-DC Single-Switch Converters

Directory of Open Access Journals (Sweden)

Barry W. Williams

2017-06-01

Full Text Available This paper presents a new family of three previously unidentified dc-to-dc converters, buck, boost, and buck-boost voltage-transfer-function topologies, which offer advantageous transformer coupling features and low capacitor dc voltage stressing. The three single-switch, single-diode, converters offer the same features as basic dc-to-dc converters, such as the buck function with continuous output current and the boost function with continuous input current. Converter time-domain simulations and experimental results (including transformer coupling support and extol the dc-to-dc converter concepts and analysis presented.

Dynamic testing of cable structures

Directory of Open Access Journals (Sweden)

Caetano Elsa

2015-01-01

Full Text Available The paper discusses the role of dynamic testing in the study of cable structures. In this context, the identification of cable force based on vibration measurements is discussed. Vibration and damping assessment are then introduced as the focus of dynamic monitoring systems, and particular aspects of the structural behaviour under environmental loads are analysed. Diverse application results are presented to support the discussion centred on cable-stayed bridges, roof structures, a guyed mast and a transmission line.

A Markovian Approach Applied to Reliability Modeling of Bidirectional DC-DC Converters Used in PHEVs and Smart Grids

Directory of Open Access Journals (Sweden)

M. Khalilzadeh

2016-12-01

Full Text Available In this paper, a stochastic approach is proposed for reliability assessment of bidirectional DC-DC converters, including the fault-tolerant ones. This type of converters can be used in a smart DC grid, feeding DC loads such as home appliances and plug-in hybrid electric vehicles (PHEVs. The reliability of bidirectional DC-DC converters is of such an importance, due to the key role of the expected increasingly utilization of DC grids in modern Smart Grid. Markov processes are suggested for reliability modeling and consequently calculating the expected effective lifetime of bidirectional converters. A three-leg bidirectional interleaved converter using data of Toyota Prius 2012 hybrid electric vehicle is used as a case study. Besides, the influence of environment and ambient temperature on converter lifetime is studied. The impact of modeling the reliability of the converter and adding reliability constraints on the technical design procedure of the converter is also investigated. In order to investigate the effect of leg increase on the lifetime of the converter, single leg to five-leg interleave DC-DC converters are studied considering economical aspect and the results are extrapolated for six and seven-leg converters. The proposed method could be generalized so that the number of legs and input and output capacitors could be an arbitrary number.

Measurement of DC electrical conductivity of alumina during spallation-neutron irradiation

International Nuclear Information System (INIS)

Farnum, E.H.; Clinard, F.W. Jr.; Kennedy, J.C. III; Sommer, W.F.; Dammeyer, M.D.

1993-01-01

An irradiation experiment was carried out during the summer of 1992 at the Los Alamos Spallation Radiation Effects Facility (LASREF). In situ measurements of electrical conductivity in alumina, sapphire and mineral-insulated electrical cables were made at 640 degrees C, 590 degrees C and 400 degrees C. Both DC and AC (100 Hz to 1 MHz) measurements were made to fluence of approximately 3 x 10 23 n/m 2 . Optical absorption from 200 nm to 800 nm was measured in pure silica - and OH-doped silica-core optical fibers during the irradiation. A large number of passive samples were included in the irradiation, some at the furnace temperatures and some at ambient temperature. This report describes preliminary analysis of the DC conductivity measurements. The AC measurements are analyzed in the companion report. All samples are being recovered for post-irradiation examination as this report is being written in May, 1993. Final analysis of the conductivity data awaits the results of measured fluence from activation foils and will be published at ICFRM-6

Motility of electric cable bacteria

DEFF Research Database (Denmark)

Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner

2016-01-01

Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...... with a highly variable speed of 0.50.3 ms1 (meanstandard deviation) and time between reversals of 155108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic......-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment....

Analysis of Electrical Coupling Parameters in Superconducting Cables

CERN Document Server

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.

Characterization of fiber optic cables under large tensile loads

International Nuclear Information System (INIS)

Ogle, J.W.; Looney, L.D.; Peterson, R.T.

1984-01-01

Fiber optic cables designed for the Nevada Test Site (NTS) have to withstand an unusually harsh environment. Cables have been manufactured under a 6 year old DOE specification that has been slightly modified as the cable requirements are better understood. In order to better understand the cable properties a unique capability has been established at the NTS. Instrumentation has been developed to characterize the transmission properties of 1 km of fiber optic cable placed under a controlled tensile load up to 1500 lbs. The properties measured are cable tension, cable elongation, induced attenuation, attenuation vs. location, fiber strain, bandwidth, and ambient temperature. Preforming these measurements on cables from the two qualified NTS fiber optic cable manufacturers, Siecor and Andrew Corp., led to a new set of specifications

A cable-driven locomotor training system for restoration of gait in human SCI.

Science.gov (United States)

Wu, Ming; Hornby, T George; Landry, Jill M; Roth, Heidi; Schmit, Brian D

2011-02-01

A novel cable-driven robotic locomotor training system was developed to provide compliant assistance/resistance forces to the legs during treadmill training in patients with incomplete spinal cord injury (SCI). Eleven subjects with incomplete SCI were recruited to participate in two experiments to test the feasibility of the robotic gait training system. Specifically, 10 subjects participated in one experimental session to test the characteristics of the robotic gait training system and one subject participated in repeated testing sessions over 8 weeks with the robotic device to test improvements in locomotor function. Limb kinematics were recorded in one experiment to evaluate the system characteristics of the cable-driven locomotor trainer and the overground gait speed and 6 min walking distance were evaluated at pre, 4 and 8 weeks post treadmill training of a single subject as well. The results indicated that the cable driven robotic gait training system improved the kinematic performance of the leg during treadmill walking and had no significant impact on the variability of lower leg trajectory, suggesting a high backdrivability of the cable system. In addition, results from a patient with incomplete SCI indicated that prolonged robotic gait training using the cable robot improved overground gait speed. Results from this study suggested that a cable driven robotic gait training system is effective in improving leg kinematic performance, yet allows variability of gait kinematics. Thus, it seems feasible to improve the locomotor function in human SCI using this cable driven robotic system, warranting testing with a larger group of patients. Copyright © 2010 Elsevier B.V. All rights reserved.

Neutron detector with gamma compensated cable

International Nuclear Information System (INIS)

Warren, H.D.

1975-01-01

An illustrative embodiment of the invention describes a technique for essentially eliminating the radiation induced background currents that are generated in the cable that connects an ''in-core'' neutron detector to an electrical terminal that is outside of the reactor's radiation field. This undesirable radiation-induced cable current is suppressed through an appropriate selection of conductor and cable sheath materials and sizes that generally satisfy the equation: Z/sub l/sup n/d/sub l/ = Z/sub s/sup m/d/sub s/ where Z is the atomic number of the material; d is a characteristic of the size of the cable component; m and/n have values between 1 and 5 to express the electron emissivity of the cable component from photoelectric and Compton effects; l represents the conductor; and s represents the sheath. Thus, the radiation-generated electrons emitted from the conductor and the oppositely-directed electrons emitted from the inner surface of the cable sheath are mutually cancelled if this equation is satisfied. A typical cable that does meet this criterion at low temperatures has a centrally disposed Zircaloy-2 inner conductor of 0.011 inch diameter, an annular insulation of magnesium oxide powder compacted to 100 percent density, and an Inconel sheath with an outside diameter of 0.062 inch and 0.011 inch wall thickness. (auth)

Some considerations on special spacers with damping device for suppressing wake galloping in tandem cables of cable-stayed bridges; Heiretsu cable yo gensui kino tsuki supesa no gensui fuka tokusei ni kansuru 2,3 no kosatsu

Energy Technology Data Exchange (ETDEWEB)

Yoneda, M. [Kinki Univ., Higashi-Osaka, Osaka (Japan). Faculty of Science and Technology] Setouchi, H. [Kawada Industries Inc., Osaka (Japan)

1998-03-20

Cable vibration called wake galloping appears on cable-stayed bridges with parallel arranged cables and its suppression is an important problem. Various methods have been proposed for spacers with damping device for suppressing wake galloping in tandem cables of cable-stayed bridges. But, comparison of damping performances of various methods have not been discussed sufficiently. This paper deals with a type in which dampers are equipped on the midway of the tandem cables through the spacer jig and a type in which dampers are equipped on each surface of the tandem cables to generate shear deformation between them and circular spacer jig moiety and complex eigenvalue analyses are carried out on the two types with changing center spacing and diameters of the cables. The results clarify the relation between the structural damping characteristics and the cable spacing and the effect of torsional rigidity of the cables and also clarify of damping characteristics of the two types. 16 refs., 14 figs., 4 tabs.

Non-linear stochastic response of a shallow cable

DEFF Research Database (Denmark)

Larsen, Jesper Winther; Nielsen, Søren R.K.

2004-01-01

The paper considers the stochastic response of geometrical non-linear shallow cables. Large rain-wind induced cable oscillations with non-linear interactions have been observed in many large cable stayed bridges during the last decades. The response of the cable is investigated for a reduced two...

Full-scale fire experiments on vertical horizontal cable trays

International Nuclear Information System (INIS)

Mangs, J.; Keski-Rahkonen, O.

1997-10-01

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, CO 2 , 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.)

Design of anti-theft/cable cut real time alert system for copper cable using microcontroller and GSM technology

Science.gov (United States)

Lim, E. K.; Norizan, M. N.; Mohamad, I. S.; Yasin, M. N. M.; Murad, S. A. Z.; Baharum, N. A.; Jamalullail, N.

2017-09-01

This paper presents the design of anti-theft/cable cut real time alert system using microcontroller and GSM technology. The detection part is using the electrical circuit wire connection in detecting the voltage drop of the cable inside the microcontroller digital input port. The GSM wireless modem is used to send the location of cable cut directly to the authority mobile phone. Microcontroller SK40C with Microchip PIC16F887 is used as a controller to control the wireless modem and also the detection device. The device is able to detect and display the location of the cable cut on the LCD display besides of and sending out the location of the cable break to the authority mobile phone wirelessly via SMS.

New method for the detection and monitoring of subsea power cable

Science.gov (United States)

Held, Philipp; Schneider, Jens; Feldens, Peter; Wilken, Dennis

2016-04-01

Marine renewable energy farms, no matter what kind of, have in common that they need a connection with the onshore power grid. Thus, not only their offshore generation facilities could have impacts on the surrounding environment, but also associated submarine power cables. These cables have to be buried in the seabed - at least in coastal heavy shipping environments - for safety reasons. Cable laying disturbs the local seafloor and the sub-bottom. Refillment of dredged sediments are expected softer than the original material and could be washed away by currents. Therefore, buried cables have to be repeatedly monitored to ensure their burial depth. This study presents a new method for efficient cable detection. A parametric echosounder system using 15 kHz as secondary frequency was adapted to investigate the angular response of sub-bottom backscatter strength of layered mud and to introduce a new method for enhanced acoustic detection of buried targets. Adaptations to achieve both vertical (0°) and non-vertical inclination of incident sound on the seabed (1-15°, 30°, 45°, and 60°) comprise mechanical tilting of the acoustic transducer and electronic beam steering. A sample data set was acquired at a study site at 18 m water depth and a flat and muddy seafloor. At this site, a 0.1 m diameter power cable is buried 1-2 m below the sea floor. Surveying the cable with vertical incidence revealed that the buried cable can hardly be discriminated against the backscatter strength of the layered mud. However, the backscatter strength of layered mud was found to strongly decrease at >3±0.5° incidence and the layered mud echo pattern vanished beyond 5°. As a consequence the visual recognition of the cable echo in acoustic images improves for higher incidence angles of 15°, 30°, 45°, and 60°. Data analysis support this visual impression. The size of the cable echo pattern was found to linearly increase with incidence, whereas the signal-to-noise ratio peaks at about

External heating of electrical cables and auto-ignition investigation

Energy Technology Data Exchange (ETDEWEB)

Courty, L., E-mail: leo.courty@univ-orleans.fr [Univ. Orleans, PRISME EA 4229, 63 Avenue de Lattre de Tassigny, 18020 Bourges (France); Garo, J.P. [Institut P’, UPR 3346 CNRS, ENSMA, Univ. Poitiers, 1 Av. Clément Ader, Téléport 2, BP 40109, 86961 Futuroscope Chasseneuil (France)

2017-01-05

Highlights: • Electrical cables pyrolysis and flammability have been studied. • Two different experimental setups were used to study cables mass loss and flammability. • A 1-D thermal model for cables mass loss and temperature is proposed. • Spontaneous and piloted ignitions have been investigated. - Abstract: Electric cables are now extensively used for both residential and industrial applications. During more than twenty years, multi-scale approaches have been developed to study fire behavior of such cables that represents a serious challenge. Cables are rather complicated materials because they consist of an insulated part and jacket of polymeric materials. These polymeric materials can have various chemical structures, thicknesses and additives and generally have a char-forming tendency when exposed to heat source. In this work, two test methods are used for the characterization of cable pyrolysis and flammability. The first one permits the investigation of cable pyrolysis. A description of the cable mass loss is obtained, coupling an Arrhenius expression with a 1D thermal model of cables heating. Numerical results are successfully compared with experimental data obtained for two types of cable commonly used in French nuclear power plants. The second one is devoted to ignition investigations (spontaneous or piloted) of these cables. All these basic observations, measurements and modelling efforts are of major interest for a more comprehensive fire resistance evaluation of electric cables.

External heating of electrical cables and auto-ignition investigation

International Nuclear Information System (INIS)

Courty, L.; Garo, J.P.

2017-01-01

Highlights: • Electrical cables pyrolysis and flammability have been studied. • Two different experimental setups were used to study cables mass loss and flammability. • A 1-D thermal model for cables mass loss and temperature is proposed. • Spontaneous and piloted ignitions have been investigated. - Abstract: Electric cables are now extensively used for both residential and industrial applications. During more than twenty years, multi-scale approaches have been developed to study fire behavior of such cables that represents a serious challenge. Cables are rather complicated materials because they consist of an insulated part and jacket of polymeric materials. These polymeric materials can have various chemical structures, thicknesses and additives and generally have a char-forming tendency when exposed to heat source. In this work, two test methods are used for the characterization of cable pyrolysis and flammability. The first one permits the investigation of cable pyrolysis. A description of the cable mass loss is obtained, coupling an Arrhenius expression with a 1D thermal model of cables heating. Numerical results are successfully compared with experimental data obtained for two types of cable commonly used in French nuclear power plants. The second one is devoted to ignition investigations (spontaneous or piloted) of these cables. All these basic observations, measurements and modelling efforts are of major interest for a more comprehensive fire resistance evaluation of electric cables.

Assessment of the burning behavior of protected and unprotected cables and cable trays in nuclear installations using small- and large-scale experiments

Energy Technology Data Exchange (ETDEWEB)

Siemon, Matthias; Riese, Olaf; Zehfuss, Jochen [Technische Univ. Braunschweig (Germany). Inst. fuer Baustoffe, Massivbau und Brandschutz (iBMB)

2015-12-15

Electric installations and cables are a main fire risk source in industrial buildings and power plants. In general, cables and cable systems are associated with flash-over phenomena due to pyrolysis of fuel gases induced by the heat of an adjacent fire, fire spread along cable trays affecting additional areas besides the fire origin, being an ignition source due to malfunction. If burning, cables can emit large amounts of smoke and toxic products affecting occupants as well as the long-term functionality of structure and installations. Paying attention to these risks has led to the development of fire retardant non-corrosive (non-halogenated) cables which are qualified to reduce the individual or all of the risks mentioned. For existing installations in industrial buildings and power plants with halogenated cables, different protection measures are available and widely applied retroactively. Important protective measures are intumescent or ablative coatings, cable casings and bindings. For qualification of the effects of the protection measures, small-scale tests investigating a single cable specimen as well as large-scale cable tray test setups have been developed and carried out in the last 20 years at iBMB. In this paper, these test results are analysed regarding their effects on the heat release, ignition time and fire spread over cable trays. Furthermore, national and international research projects have investigated the burning behaviour of different cable types, tray installations, tray loading and spacing and ventilation conditions. As a conclusion, the main outcomes of past researches are summarized. Influence factors (e.g. pre-heating due to high power utilization, influence of cable aging) which have not been accounted for in detail are emphasized. The modelling of unprotected cables has been internationally studied in recent years. For future applications, the question of applicability of recently developed sub-models on the fire behaviour of protected

75 FR 60602 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

Science.gov (United States)

2010-10-01

... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10... adding the following new AD: 2010-20-14 McDonnell Douglas Corporation: Amendment 39-16449. Docket No. FAA... the airplanes identified in paragraphs (c)(1) and (c)(2) of this AD. (1) McDonnell Douglas Corporation...

75 FR 38943 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-30, DC...

Science.gov (United States)

2010-07-07

...-0672; Directorate Identifier 2010-NM-047-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas...: McDonnell Douglas Corporation: Docket No. FAA-2010-0672; Directorate Identifier 2010-NM-047-AD. Comments Due... applies to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10), DC-10...

Similarity Analysis of Cable Insulations by Chemical Test

Energy Technology Data Exchange (ETDEWEB)

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.

Similarity Analysis of Cable Insulations by Chemical Test

International Nuclear Information System (INIS)

Kim, Jong Seog

2013-01-01

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

High voltage pulsed cable design: a practical example

International Nuclear Information System (INIS)

Kewish, R.W. Jr.; Boicourt, G.P.

1979-01-01

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

High voltage pulsed cable design: a practical example

Energy Technology Data Exchange (ETDEWEB)

Kewish, R.W. Jr.; Boicourt, G.P.

1979-01-01

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.

47 CFR 76.802 - Disposition of cable home wiring.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Disposition of cable home wiring. 76.802... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Inside Wiring § 76.802 Disposition of cable home wiring. (a)(1) Upon voluntary termination of cable service by a subscriber in a single unit installation, a...

75 FR 6160 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

Science.gov (United States)

2010-02-08

...-0032; Directorate Identifier 2009-NM-213-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas...: McDonnell Douglas Corporation: Docket No. FAA-2010-0032; Directorate Identifier 2009-NM-213-AD. Comments Due... applies to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A...

Current distribution in Cable-In-Conduit Conductors

International Nuclear Information System (INIS)

Ferri, M.A.

1994-05-01

A numerical study of the current distribution in Cable-In-Conduit Conductors (CICC's) experiencing linearly ramping transport currents and transverse magnetic fields was conducted for both infinitely long, periodic cables and finite length cables terminated in low resistance joints. The goal of the study was to gain insight into the phenomenon known as Ramp Rate Limitation, an as yet unexplained correspondence between maximum attainable current and the ramp time taken to reach that current in CICC superconducting magnets. A discrete geometric model of a 27 strand multiply twisted CICC was developed to effectively represent the flux linkages, mutual inductances, and resistive contact points between the strands of an experimentally tested cable. The results of the numerical study showed that for fully periodic cables, the current imbalances due to ramping magnetic fields and ramping transport currents are negligible in the range of experimentally explored operating conditions. For finite length, joint terminated cables, however, significant imbalances can exist. Unfortunately, quantitative results are limited by a lack of knowledge of the transverse resistance between strands in the joints. Nonetheless, general results are presented showing the dependency of the imbalance on cable length, ramp time, and joint resistance for both ramping transverse magnet fields and ramping transport currents. At the conclusion of the study, it is suggested that calculated current imbalances in a finite length cable could cause certain strands to prematurely ''quench'' -- become non-superconducting --thus leading to an instability for the entire cable. This numerically predicted ''current imbalance instability'' is compared to the experimentally observed Ramp Rate Limitation for the 27 strand CICC sample

Control and modulation for loss minimization for dc/dc converters in wind farm

DEFF Research Database (Denmark)

Dincan, Catalin Gabriel; Kjær, Philip Carne

2016-01-01

For a DC wind turbine, a single phase series-resonant converter for unidirectional power is studied. This paper aims to identify and compare impact on electrical losses and component ratings from the choice of three candidate control strategies. The evaluation is purely based on circuit simulatio...

submitter On Roebel Cable Geometry for Accelerator Magnet

CERN Document Server

Fleiter, J; Ballarino, A

2016-01-01

Roebel-type cables made of a ReBCO conductor are potential candidates for high-field accelerator magnets. The necessity to promote a large effective transverse section in a Roebel cable to avoid local overstress leading to degradation in electrical performance has been recently addressed. In this paper, a new geometry of meander tapes for a Roebel cable that enhances both the transverse effective section and the current margin at crossing segments is discussed. As Roebel cables are bent at the coil ends, the modulation of the bending radius of strands along the cable pitch leads to a shift of the strands with respect to each other. The shift magnitude is analytically investigated in this paper as a function of both cable features and coil geometry. Finally, the minimum transposition pitch of Roebel cables is determined on the basis of coil characteristics.

Wire in the Cable-Driven System of Surgical Robot

Science.gov (United States)

Wang, X. F.; Lv, N.; Mu, H. Z.; Xue, L. J.

2017-07-01

During the evolution of the surgical robot, cable plays an important role. It translates motion and force precisely from surgeon’s hand to the tool’s tips. In the paper, the vertical wires, the composition of cable, are mathematically modeled from a geometric point of view. The cable structure and tension are analyzed according to the characteristics of wire screw twist. The structural equations of the wires in different positions are derived for both non-bent cable and bent cable, respectively. The bending moment formula of bent cable is also obtained. This will help researchers find suitable cable and design more matched pulley.

ASSESSMENT OF CABLE AGING USING CONDITION MONITORING TECHNIQUES

International Nuclear Information System (INIS)

GROVE, E.; LOFARO, R.; SOO, P.; VILLARAN, M.; HSU, F.

2000-01-01

Electric cables in nuclear power plants suffer degradation during service as a result of the thermal and radiation environments in which they are installed. Instrumentation and control cables are one type of cable that provide an important role in reactor safety. Should the polymeric cable insulation material become embrittled and cracked during service, or during a loss-of-coolant-accident (LOCA) and when steam and high radiation conditions are anticipated, failure could occur and prevent the cables from fulfilling their intended safety function(s). A research program is being conducted at Brookhaven National Laboratory to evaluate condition monitoring (CM) techniques for estimating the amount of cable degradation experienced during in-plant service. The objectives of this program are to assess the ability of the cables to perform under a simulated LOCA without losing their ability to function effectively, and to identify CM techniques which may be used to determine the effective lifetime of cables. The cable insulation materials tested include ethylene propylene rubber (EPR) and cross-linked polyethylene (XLPE). Accelerated aging (thermal and radiation) to the equivalent of 40 years of service was performed, followed by exposure to simulated LOCA conditions. The effectiveness of chemical, electrical, and mechanical condition monitoring techniques are being evaluated. Results indicate that several of these methods can detect changes in material parameters with increasing age. However, each has its limitations, and a combination of methods may provide an effective means for trending cable degradation in order to assess the remaining life of cables

Connected Lighting Systems Efficiency Study$-$ PoE Cable Energy Losses, Part 1

Energy Technology Data Exchange (ETDEWEB)

Tuenge, Jason [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kelly, Karsten [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Poplawski, Michael [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-11-30

First report in a study of the efficiency of connected lighting systems. The report summarizes the results of an exploratory study investigating power losses in Ethernet cables used between PoE switches and luminaires in PoE connected lighting systems. Testing was conducted at the Pacific Northwest National Laboratory (PNNL) Connected Lighting Test Bed in September 2017. The results were analyzed to explore the impact of cable selection on PoE lighting system energy efficiency, as well as the effectiveness of guidelines recently introduced by the American National Standards Institute (ANSI) C137 Lighting Systems Committee.

75 FR 61989 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-8-31, DC-8-32, DC-8-33, DC-8-41...

Science.gov (United States)

2010-10-07

... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, and... to all of the McDonnell Douglas Corporation airplanes identified above. The existing AD currently... the following new airworthiness directive (AD): 2010-21-03 McDonnell Douglas Corporation: Amendment 39...

Strengthening of bridges by post-tensioning using monostrands in substituted cable ducts

Science.gov (United States)

Klusáček, Ladislav; Svoboda, Adam

2017-09-01

Post-tensioning is suitable, reliable and durable method of strengthening existing engineering structures, especially bridges. The high efficiency of post-tensioning can be seen in many applications throughout the world. In this paper the method is extended by a structural system of substituted cable ducts, which allows for significantly widening application of prestressing so it’s convenient mostly for application on beam bridges or slab bridges (built in years 1920 - 1960). The method of substituted cable ducts is based on theoretical knowledge and technical procedures, which were made possible through the development in prestressing systems, particularly the development of prestressing tendons (monostrands) and encased anchorages, as well as progress in drilling technology. This technique is highly recommended due to minimization of interventions into the constructions, unseen method of cable arrangement and hence the absence of impact on appearance, which is appreciated not only in case of valuable historical structures but also in general. It is possible to summarise that posttensioning by monostrands in substituted cable ducts is a highly effective method of strengthening existing bridges in order to increase their load capacities in terms of current traffic load and to extend their service life.

Comparison of advanced high power underground cable designs

International Nuclear Information System (INIS)

Erb, J.; Heinz, W.; Hofmann, A.; Koefler, H.J.; Komarek, P.; Maurer, W.; Nahar, A.

1975-09-01

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, SF 6 -cables, polyethylene cables, cryoresistive and superconducting cables. (orig.) [de

An industrial cabling machine for the SSC

International Nuclear Information System (INIS)

Royet, J.; Armer, R.; Hannaford, R.; Scanlan, R.

1989-02-01

The SSC project will need the manufacturing of some 25,000 kilometers of keystoned flat cable. The technical specifications of the various cables to be produced are the result of five years of research and development work at LBL. An experimental cable machine was built and run in the laboratory; many improvements were implemented and tested. Semi-industrial production of the various cables was performed, and the resulting cables were used and tested in the one-meter model magnets and 17.5 meter dipole prototypes. From these experiments an industrial cabler specification was generated and used for an international RFQ. The winner of the contract is Dour Metal, a Belgium company that built the first industrial prototype which is now in a production line at New England Electric Wire Company. In this paper we describe the main characteristics of the machine and give the first industrial production results of superconducting keystoned cable for the SSC project. 4 refs

Proceedings of the International Wire and Cable Symposium (32nd) Held at Cherry Hill, New Jersey on November 15, 16 and 17, 1983.

Science.gov (United States)

1983-11-17

34 tion principle allows the fabrication of /6/ Zielinski , H.G., S. Mlinger, Fibre long cable lengths adopted to the expec- Optical Coupling Techniques and... Dave graduated in 1949 from Georgetown University, Washington, D.C., with BS in Chemistry. He performed graduate work at Northwestern University in...Marketing prior to serving in U.S. Army, Chemical Corps. Dave joined Du Pont in 1954 after leaving the Army. His present assignment as Senior Development

47 CFR 76.111 - Cable sports blackout.

Science.gov (United States)

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 specified...

Dynamic model and workspace analysis of novel incompletely restrained cable-suspension swing system driven by two cables

Directory of Open Access Journals (Sweden)

Naige Wang

2017-03-01

Full Text Available The incompletely restrained cable-suspension swing system driven by two cables is introduced in this article. Based on wrench of forces theory and Lagrange’s equation of first kind, the static and dynamics models of incompletely restrained cable-suspension swing system driven by two cables are established, respectively. In order to obtain an intuitive understanding of the trajectory analysis, a dynamics model consisting of governing equation and geometric constraint conditions which is a set of the mixed differential-algebraic equation in mathematics is established. A typical feedback controller and an inverse model were set up to estimate the driving function. The effective workspace, which is used to guarantee an efficient swing process, mostly depends on the geometrical shape rather than the volume itself which was calculated by trajectory analysis. In order to estimate system features and ensure a limited range of tension in underconstrained spatial cable system, the probable location of unbalanced loading was evaluated by pointwise evaluation techniques during normal work.

Configuration Synthesis for Fully Restrained 7-Cable-Driven Manipulators

Directory of Open Access Journals (Sweden)

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.

Cable condition monitoring in a pressurized water reactor environment

International Nuclear Information System (INIS)

Al-Hussaini, T.J.

1988-01-01

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

Multi Bus DC-DC Converter in Electric Hybrid Vehicles

Science.gov (United States)

Krithika, V.; Subramaniam, C.; Sridharan, R.; Geetha, A.

2018-04-01

This paper is cotncerned with the design, simulation and fabrication of the prototype of a Multi bus DC- DC converter operating from 42V DC and delivering 14V DC and 260V DC. As a result, three DC buses are interconnected through a single power electronic circuitry. Such a requirement is energized in the development of a hybrid electric automobile which uses the technology of fuel cell. This is implemented by using a Bidirectional DC-DC converter configuration which is ideally suitable for multiple outputs with mutual electrical isolation. For the sake of reduced size and cost of step-up transformer, selection of a high frequency switching cycle at 10 KHz was done.

Step-Up DC-DC Power Converter

DEFF Research Database (Denmark)

2015-01-01

The present invention relates to a step-up DC-DC power converter which comprises a primary side circuit and a secondary side circuit coupled through a galvanic isolation barrier. The primary side circuit comprises a positive and a negative input terminal for receipt of an input voltage and an input...... being charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier in accordance with a switch control signal to produce the converter output voltage. The step-up DC-DC power converter comprises an electrical short-circuit connection across the galvanic...

Commercialization of Medium Voltage HTS Triax TM Cable Systems

Energy Technology Data Exchange (ETDEWEB)

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.

AC-DC PFC Converter Using Combination of Flyback Converter and Full-bridge DC-DC Converter

Directory of Open Access Journals (Sweden)

Moh. Zaenal Efendi

2014-06-01

Full Text Available This paper presents a combination of power factor correction converter using Flyback converter and Full-bridge dc-dc converter in series connection. Flyback converter is operated in discontinuous conduction mode so that it can serve as a power factor correction converter and meanwhile Full-bridge dc-dc converter is used for dc regulator. This converter system is designed to produce a 86 Volt of output voltage and 2 A of output current. Both simulation and experiment results show that the power factor of this converter achieves up to 0.99 and meets harmonic standard of IEC61000-3-2. Keywords: Flyback Converter, Full-bridge DC-DC Converter, Power Factor Correction.

Early Oscillation Detection for DC/DC Converter Fault Diagnosis

Science.gov (United States)

Wang, Bright L.

2011-01-01

The electrical power system of a spacecraft plays a very critical role for space mission success. Such a modern power system may contain numerous hybrid DC/DC converters both inside the power system electronics (PSE) units and onboard most of the flight electronics modules. One of the faulty conditions for DC/DC converter that poses serious threats to mission safety is the random occurrence of oscillation related to inherent instability characteristics of the DC/DC converters and design deficiency of the power systems. To ensure the highest reliability of the power system, oscillations in any form shall be promptly detected during part level testing, system integration tests, flight health monitoring, and on-board fault diagnosis. The popular gain/phase margin analysis method is capable of predicting stability levels of DC/DC converters, but it is limited only to verification of designs and to part-level testing on some of the models. This method has to inject noise signals into the control loop circuitry as required, thus, interrupts the DC/DC converter's normal operation and increases risks of degrading and damaging the flight unit. A novel technique to detect oscillations at early stage for flight hybrid DC/DC converters was developed.

Electrical cabling system associated at a nuclear reactor

International Nuclear Information System (INIS)

Dejeux, P.; Desfontaines, G.

1988-01-01

This cabling system for an electrical device in a nuclear reactor comprises at least a first cable issued of the device, a second cable comprising a first portion, a second portion and a third portion joining the second by a multiple quick fitting connector capable to connect at least ten second portions at ten other third portions of the second cable [fr

Results of winglet development studies for DC-10 derivatives

Science.gov (United States)

Shollenberger, C. A.; Humphreys, J. W.; Heiberger, F. S.; Pearson, R. M.

1983-01-01

The results of investigations into the application of winglets to the DC-10 aircraft are presented. The DC-10 winglet configuration was developed and its cruise performance determined in a previous investigation. This study included high speed and low speed wind tunnel tests to evaluate aerodynamic characteristics, and a subsonic flutter wind tunnel test with accompanying analysis and evaluation of results. Additionally, a configuration integration study employed the results of the wind tunnel studies to determine the overall impact of the installation of winglets on the DC-10 aircraft. Conclusions derived from the high speed and low speed tests indicate that the winglets had no significant effects on the DC-10 stability characteristics or high speed buffet. It was determined that winglets had a minimal effect on aircraft lift characteristics and improved the low speed aircraft drag under high lift conditions. The winglets affected the DC-10 flutter characteristics by reducing the flutter speed of the basic critical mode and introducing a new critical mode involving outer wing torsion and longitudinal bending. The overall impact of winglets was determined to be of sufficient benefit to merit flight evaluation.

Design and implementation of current fed DC-DC converter for PHEV application using renewable source

Science.gov (United States)

Milind Metha, Manish; Tutki, Sanjay; Rajan, Aju; Elangovan, D.; Arunkumar, G.

2017-11-01

As the fossil fuels are depleting day by day, the use of renewable energy sources came into existence and they evolved a lot lately. To increase efficiency and productivity in the hybrid vehicles, the existence less efficient petroleum and diesel IC engines need to be replaced with the new and efficient converters with renewable energy sources. This has to be done in such a way that impacts three factors mainly: cost, efficiency and reliability. The PHEVs that have been launched and the upcoming PHEVs using converters with voltage range around 380V to 400V generated with power ranges between 2.4KW to 2.8KW. The basic motto of this paper is to design a prolific converter while considering the factor such as cost and size. In this paper, a two stage DC-DC converter is proposed and the proposed DC-DC converter is utilized to endeavour voltage from 24V (photovoltaic source) to a yield voltage of 400V and to meet the power demand of 250W, since only one panel is being used for this proposed paper. This paper discuss in detail about why and how the current fed DC-DC converter is utilized along with a voltage doubler, thus reducing transformer turns and thereby reducing overall size of the product. Simulation and hardware results have been presented along with calculations for duty cycle required for firing sequence for different values of transformer turns.

Versatile cable handling mechanisms for remote operator control

Energy Technology Data Exchange (ETDEWEB)

Collie, A.A.; White, T.S.; Christopher, M.D.; Hewer, N.D. [Portech Ltd., Portsmouth (United Kingdom)

1996-12-31

This paper describes a system of cable management for keeping the umbilical cables of remote operating vehicles and manipulators tidy and contained without direct intervention by operators. Two distinct types of winding mechanism have been designed. One mechanism is a fixed reel type where the cable is wound onto the reel by a rotating bail arm. The other mechanism consists of a pair of curved belts held against each other between which cable is passed. The complete system includes tension measuring and slack loop take-up devices. The whole system is controlled by a servo system in conjunction with a PC based visual graphic environment which allows a variety of mechanisms to be built up into a system able to handle up to four umbilical cables simultaneously. The control system provides additional tension sensors and cable odometers connected to the control system so that the operator has immediate perception of all the cable parameters, and by defining rules, can set up a variety of alarm situations. (Author).

Versatile cable handling mechanisms for remote operator control

International Nuclear Information System (INIS)

Collie, A.A.; White, T.S.; Christopher, M.D.; Hewer, N.D.

1996-01-01

This paper describes a system of cable management for keeping the umbilical cables of remote operating vehicles and manipulators tidy and contained without direct intervention by operators. Two distinct types of winding mechanism have been designed. One mechanism is a fixed reel type where the cable is wound onto the reel by a rotating bail arm. The other mechanism consists of a pair of curved belts held against each other between which cable is passed. The complete system includes tension measuring and slack loop take-up devices. The whole system is controlled by a servo system in conjunction with a PC based visual graphic environment which allows a variety of mechanisms to be built up into a system able to handle up to four umbilical cables simultaneously. The control system provides additional tension sensors and cable odometers connected to the control system so that the operator has immediate perception of all the cable parameters, and by defining rules, can set up a variety of alarm situations. (Author)

Versatile cable handling mechanisms for remote operator control

International Nuclear Information System (INIS)

Collie, A.A.; White, T.S.; Christopher, M.D.; Hewer, N.D.

1996-01-01

This paper describes a system of cable management for keeping the umbilical cables of remote operating vehicles and manipulators tidy and contained without direct intervention by operators. Two distinct types of winding mechanism have been designed. One mechanism is a fixed reel type where the cable is wound onto the reel by a rotating bail arm. The other mechanism consists of a pair of curved belts held against each other, between which cable is passed. The complete system includes tension measuring and slack loop take-up devices. The whole system is controlled by a servo system in conjunction with a PC based visual graphic environment which allows a variety of mechanisms to be built up into a system able to handle up to four umbilical cables simultaneously. The control system provides additional tension sensors and cable odometers connected to the control system so that the operator has immediate perception of all the cable parameters, and by defining rules, can set up a variety of alarm situations. (UK)

External heating of electrical cables and auto-ignition investigation.

Science.gov (United States)

Courty, L; Garo, J P

2017-01-05

Electric cables are now extensively used for both residential and industrial applications. During more than twenty years, multi-scale approaches have been developed to study fire behavior of such cables that represents a serious challenge. Cables are rather complicated materials because they consist of an insulated part and jacket of polymeric materials. These polymeric materials can have various chemical structures, thicknesses and additives and generally have a char-forming tendency when exposed to heat source. In this work, two test methods are used for the characterization of cable pyrolysis and flammability. The first one permits the investigation of cable pyrolysis. A description of the cable mass loss is obtained, coupling an Arrhenius expression with a 1D thermal model of cables heating. Numerical results are successfully compared with experimental data obtained for two types of cable commonly used in French nuclear power plants. The second one is devoted to ignition investigations (spontaneous or piloted) of these cables. All these basic observations, measurements and modelling efforts are of major interest for a more comprehensive fire resistance evaluation of electric cables. Copyright © 2016 Elsevier B.V. All rights reserved.

Superconducting energy stabilizer with charging and discharging DC-DC converters

International Nuclear Information System (INIS)

Kim, S.H.; Kostecki, E.L.; DeWinkel, C.C.

1992-01-01

This patent describes a superconducting energy stabilizer having multiple load connections and employing DC-DC conversion for storing energy in a superconducting inductive energy storage device having a first end and a second end, and for releasing the stored energy from the superconducting inductive energy storage device to a load or loads or to a utility or an industrial electrical distribution system, the superconducting energy stabilizer having multiple load connections and employing DC-DC conversion. It comprises: energy storage cell means for supplying energy to the load, discharging DC-DC converter means for releasing energy from the superconducting inductive energy storage device to the energy storage cell means, the discharging DC-DC converter means having input terminals, output terminals, and a discharging control line means for carrying signals controlling the operation of the discharging DC-DC converter means, one of the input terminals of the discharging DC-DC converter means coupled to the first end of the superconducting energy storage device

Elasticity and mechanical advantage in cables and ropes

International Nuclear Information System (INIS)

O'Shea, M J

2007-01-01

The conditions under which one can gain mechanical advantage by pulling with a force F perpendicular to a cable (or rope) that is fixed at both ends are examined. While this is a commonly discussed example in introductory physics classes, its solution in terms of fundamental properties of the cable requires one to model the elasticity of the cable. This solution has several complex and interesting features, e.g. a large increase in the tension in the cable may occur upon application of F if (i) F lies in a certain range and (ii) the initial tension T 1 in the cable (before F is applied) satisfies T 1 < 0.0340 κ. Here, κ is the spring constant of a unit length of the cable. For steel cables and cables composed of other materials such as carbon nanorods where the elasticity is low, significant increases in tension are possible. Examples involving walking a tightrope and attempting to increase the tension in a rope hauling a load are considered. Two programs to solve the equations of this work are available in the electronic version of this journal

Remote Acquisition Amplifier For 50-Ohm Cable

Science.gov (United States)

Amador, Jose J.

1995-01-01

Buffer-amplifier unit designed to drive 50-Ohm cables up to 100 ft. (30 m) long, compensating for attenuation in cables and enabling remote operation of oscilloscopes. Variable resistor provides for adjustment of gain of amplifier, such that overall gain from input terminals of amplifier to output end of cable set to unity.

metrological performance improvement of a superconducting cable test station

CERN Document Server

Montenero, Giuseppe; Ballarino, Amalia

The work presented in this PhD thesis concerns the metrological performance improvement of a superconducting cable test station based on superconducting transformers. The main cable’s parameter to be assessed –as a function of temperature and magnetic field– is the critical current, i.e. beyond this limit the phase transition to the normal state occurs. Ramping the current at levels in the order of the tens of kA can be achieved with superconducting transformers at moderate capital and operational cost. But, issues such as (i) accurate/precise measurements and (ii) monitoring of the secondary current during the device operation have to be addressed. In this regard, the goals of the thesis are the design, prototyping, and validation of a new cryogenic current transducer and effective monitoring system for test stations transformer-based. Among the available transducers for current sensing at room temperature, the DC current transformer (DCCT) provides measurement accuracy in the order of the hundreds of ...

Comparison of programmed and cabled re-entrance systems. Elaboration of cabled re-entrance system for a CII 90.40; Comparaison des systemes de reentrance programmes et cables. Realisation d'un systeme de reentrance cable pour un CII 90.40

Energy Technology Data Exchange (ETDEWEB)

Perraudeau, Jean

1976-11-26

The objective of this research thesis is to study problems related to re-entrance, and, more particularly, to study a re-entrance system for a CII 90.40 computer. Such a system can be realised under a programmed or cabled form, and both approaches are described and compared. A generalisation of this comparison is briefly proposed. As the computer already possesses a programmed re-entrance system, the author focuses on the study of the cabled re-entrance system which results in an improvement of performance and possibilities provided by this computer, particularly for its use in real time. The design, realisation and development of such a cabled system are reported. A first part reports a theoretical study on re-entrance (definition, problems, applications), a presentation of the computer, a description of the programmed re-entrance system, a presentation of the principle of the chosen cabled re-entrance system, a definition of the structure and operating mode of the cabled pile and a description of its various components, and a flowchart analysis of function execution. The second part reports the practical realisation: definition, technological overview, technology used in the cabled pile, sequencing and multiplexing principle, impulse transmission, logical layouts, and circuit adjustments. The third part presents practical example. An assessment and perspectives are finally discussed.

Light Water Reactor Sustainability Program: Evaluation of Localized Cable Test Methods for Nuclear Power Plant Cable Aging Management Programs

Energy Technology Data Exchange (ETDEWEB)

Glass, Samuel W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hartman, Trenton S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-05-30

This Pacific Northwest National Laboratory (PNNL) milestone report describes progress to date on the investigation of nondestructive test (NDE) methods focusing particularly on local measurements that provide key indicators of cable aging and damage. The work includes a review of relevant literature as well as hands-on experimental verification of inspection capabilities. As NPPs consider applying for second, or subsequent, license renewal (SLR) to extend their operating period from 60 years to 80 years, it important to understand how the materials installed in plant systems and components will age during that time and develop aging management programs (AMPs) to assure continued safe operation under normal and design basis events (DBE). Normal component and system tests typically confirm the cables can perform their normal operational function. The focus of the cable test program is directed toward the more demanding challenge of assuring the cable function under accident or DBE. Most utilities already have a program associated with their first life extension from 40 to 60 years. Regrettably, there is neither a clear guideline nor a single NDE that can assure cable function and integrity for all cables. Thankfully, however, practical implementation of a broad range of tests allows utilities to develop a practical program that assures cable function to a high degree. The industry has adopted 50% elongation at break (EAB) relative to the un-aged cable condition as the acceptability standard. All tests are benchmarked against the cable EAB test. EAB is a destructive test so the test programs must apply an array of other NDE tests to assure or infer the overall set of cable’s system integrity. These cable NDE programs vary in rigor and methodology. As the industry gains experience with the efficacy of these programs, it is expected that implementation practice will converge to a more common approach. This report addresses the range of local NDE cable tests that are

Superconducting power cables in Denmark - a case study

DEFF Research Database (Denmark)

Østergaard, Jacob

1997-01-01

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...... that 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...

46 CFR 111.12-9 - Generator cables.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Generator cables. 111.12-9 Section 111.12-9 Shipping... REQUIREMENTS Generator Construction and Circuits § 111.12-9 Generator cables. (a) The current-carrying capacity of generator cables must not be: (1) Less than 115 percent of the continuous generator rating; or (2...

Development of scaling rules for Rutherford type superconducting cables

International Nuclear Information System (INIS)

Royet, J.M.; Scanlan, R.M.

1991-01-01

During the R and D phase of the Superconducting Supercollider (SSC) program, LBL was responsible for establishing the parameters for cables used in SSC dipole and quadrupole magnets. In addition, LBL has collaborated with Fermi National Accelerator Laboratory on the design and fabrication of a new cable for use in the Low Beta Quadrupoles. As a result of the development work on these and other cables, we have arrived a set of scaling rules which provide guidelines for choosing the parameters for a wide range of superconducting cables. These parameters include strand size, strand number, keystone angle, percent compaction, cable pitch and compacted cable dimensions. In addition, we have defined the tolerance ranges for the key cable manufacturing parameters such as mandrel size and shape, strand tension, and Turkshead temperature control. In this paper, the authors present the results on cables ranging from 8 strands to 36 strands of 0.65mm wire and from 8 strands to 30 strands of 0.8mm wire. The authors use these results to demonstrate the application of the scaling rules for Rutherford-type cable

Development of scaling rules for Rutherford type superconducting cables

International Nuclear Information System (INIS)

Royet, J.M.; Scanlan, R.M.

1990-09-01

During the R ampersand D phase of the Superconducting Supercollider (SSC) program, LBL was responsible for establishing the parameters for cables used in SSC dipole and quadrupole magnets. In addition, the design and fabrication of a new cable for use in the Low Beta Quadrupoles. As a result of the development work on these and other cables, we have arrived a set of scaling rules which provide guidelines for choosing the parameters for a wide range of superconducting cables. These parameters include strand size, strand number, keystone angle, percent compaction, cable pitch and compacted cable dimensions. In addition, we have defined the tolerance ranges for the key cable manufacturing parameters such as mandrel size and shape, stand tension, and Turkshead temperature control. In this paper, we present the results on cables ranging from 8 strands to 36 strands of 0.65mm wire and from 8 strands to 30 strands of 0.8mm wire. We use these results to demonstrate the application of the scaling rules for Rutherford-type cable

Data Base On Cables And Connectors

Science.gov (United States)

Bowen, Arlen R.; Oliver, John D.

1995-01-01

Report describes Connector Adapter Cable Information Data Base (CONNAID) computer program, managing data base containing necessary information concerning electrical connectors, breakout boxes, adapter cables, backshells, and pertinent torque specifications for engineering project.

Manufacturing experience for the LHC inner triplet quadrupole cables

CERN Document Server

Scanlan, R M; Bossert, R; Kerby, J S; Ghosh, A K; Boivin, M; Roy, T

2002-01-01

The design for the U.S. LHC Inner Triplet Quadrupole magnet requires a 37 strand (inner layer) and a 46 strand (outer layer) cable. This represents the largest number of strands attempted to date for a production quantity of Rutherford-type cable. The cable parameters were optimized during the production of a series of short prototype magnets produced at FNAL. These optimization studies focused on critical current degradation, dimensional control, coil winding, and interstrand resistance. After the R&D phase was complete, the technology was transferred to NEEW and a new cabling machine was installed to produce these cables. At present, about 60 unit lengths, out of 90 required for the entire production series of magnets, have been completed for each type of cable. The manufacturing experience with these challenging cables will be reported. Finally, the implications for even larger cables, with more strands, will be discussed. (8 refs).

Cable Television in Sedalia, Missouri.

Science.gov (United States)

Lamkin, Kathryn Janel

A field study was conducted of the status of cable television in Sedalia, Missouri. Based on interviews of city council members and staff members of Cablevision, the Sedalia cable franchise holder, the following issues were investigated: (1) subscription rates; (2) franchise negotiations; (3) quality of existing services; and (4) possible…

Milliwatt dc/dc Inverter

Science.gov (United States)

Mclyman, C. W.

1983-01-01

Compact dc/dc inverter uses single integrated-circuit package containing six inverter gates that generate and amplify 100-kHz square-wave switching signal. Square-wave switching inverts 10-volt local power to isolated voltage at another desired level. Relatively high operating frequency reduces size of filter capacitors required, resulting in small package unit.

75 FR 63040 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-30, DC...

Science.gov (United States)

2010-10-14

... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10... following new airworthiness directive (AD): 2010-21-13 McDonnell Douglas Corporation: Amendment 39-16473... November 18, 2010. Affected ADs (b) None. Applicability (c) This AD applies to McDonnell Douglas...

75 FR 68246 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

Science.gov (United States)

2010-11-05

...-1044; Directorate Identifier 2010-NM-033-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas..., 2007) and adding the following new AD: McDonnell Douglas Corporation: Docket No. FAA-2010-1044.... Applicability (c) This AD applies to all McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

High power cable with internal water cooling 400 kV

Science.gov (United States)

Rasquin, W.; Harjes, B.

1982-08-01

Due to the concentration of electricity production in large power plants, the need of higher power transmissions, and the protection of environment, developement of a 400 kV water cooled cable in the power range of 1 to 5 GVA was undertaken. The fabrication and testing of equipment, engineering of cable components, fabrication of a test cable, development of cable terminal laboratory, testing of test cable, field testing of test cable, fabrication of industrial cable laboratory, testing of industrial cable, field testing of industrial cable, and system analysis for optimization were prepared. The field testing was impossible to realize. However, it is proved that a cable consisting of an internal stainless steel water cooled tube, covered by stranded copper profiles, insulated with heavy high quality paper, and protected by an aluminum cover can be produced, withstand tests accordingly to IEC/VDE recommendations, and is able to fulfill all exploitation conditions.

Aircraft Accident Report; Uncontrolled Impact with Terrain, Fine Airlines Flight 101, Douglas DC-8-61, N27UA, Miami, Florida, August 7, 1997

Science.gov (United States)

1998-06-16

Transcolombiana de Carga ATI Air Transport International ATOS Air Transportation Oversight System ATP airline transport pilot CAM cockpit area microphone...495,000 fine against Aero Transcolombiana de Carga (ATC) for operating a DC-8-51 "over the weight limits set forth in its FAA-approved flight manual...PB98-910402 NTSB/AAR-98/02 DCA97MA059 NATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. 20594 AIRCRAFT ACCIDENT REPORT c>C== UNCONTROLLED IMPACT

Overview of Multi-DC-Bus Solutions for DC Microgrids

DEFF Research Database (Denmark)

Ricchiuto, D.; Mastromauro, R.A.; Liserre, Marco

2013-01-01

DC Microgrids have recently received a lot of attention in the last years due to high penetration of renewable energy sources as well as distributed energy storage systems. In the future DC microgrids could be preferable respect to AC microgrids in terms of redundancy since multi-DC-Bus solutions...... could provide a continuative power supply to the loads. An overview of Multi-DC-Bus solutions is presented in this paper. The performances are compared on the basis of possible DC microgrid configurations, redundancy, different DC voltage levels....

CSNS control cable information management system based on web

International Nuclear Information System (INIS)

Lu Huihui; Wang Chunhong; Li Luofeng; Liu Zhengtong; Lei Bifeng

2014-01-01

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)

Cable-to-post attachments for use in non-proprietary high-tension cable median barrier - phase II.

Science.gov (United States)

2016-03-24

The objective of this study was to reevaluate and improve the existing cable-to-post attachment hardware that is utilized : in the non-proprietary cable barrier being developed at MwRSF. The study focused on redesigning the bolted, tabbed : bracket (...

Practical cable tension adjustment based upon the satisfaction concept of bridge designers; Sekkeisha no manzokudo wo koryo shita fuzzy cable choryoku choseiho

Energy Technology Data Exchange (ETDEWEB)

Kaneyoshi, M.; Tanaka, H. [Hitachi Zosen, Tokyo (Japan)] Furuta, H. [Kansai Univ., Osaka (Japan)

1998-07-21

Cable tension adjustment of bridge beam of cable stayed bridge and so forth that uses cable as a structural element is classified into (1) pre-stress adjustment of cable at design level, (2) slim adjustment required at erection level. The former deals with the structurally high dimensional statically indeterminate structures like cable-stayed bridges and is a process for carrying out economical design by making the stress resultant of main girder small due to the introduction of appropriate pre-stress stress on this cable. The later is the process of getting rid off the errors caused in cable tension and camber of girder and tower regarding various errors such as design, fabrication and erection errors. The authors developed analysis method using fuzzy regression analysis and this has been applied in number of practical bridges. In this research, much more practical method is developed where the aspire of designer can be introduced easily by applying the satisfaction concept. By using this, pre-stress adjustment and shim adjustment of cable can be possible in a practical way. 9 refs., 7 figs., 8 tabs.

Development of low-smoke, flame-retarding cables

International Nuclear Information System (INIS)

Kato, H.; Kanemitsuya, K.; Furukawa, K.; Mio, K.

1983-01-01

A great deal of attention has been given to the potential fire hazard of combustion gases from organic materials. Although cable industries have developed flame-retarding organic materials for the insulation and jacketing of wires and cables, there was insufficient prevention of toxic gas formation during combustion. To cope with these problems associated with conventional PVC cables, the authors have directed to develop low-smoke, flame-retarding plasticized PVC formulations retaining the original mechanical, electrical and aging properties. A series of basic investigations on smoke suppression followed by an evaluation on practical cables could indicate some effective means to end these problems. This paper describes the results and discussion on smoke suppressing study of plasticized PVC as well as behavior and characteristics of the low-smoke, flame-retarding PVC wires and cables using these materials. (author)

Losses in armoured three-phase submarine cables

DEFF Research Database (Denmark)

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 installation of cables with excessive phase conductor cross section. This paper also presents an example of the potential economic benefits of having a better knowledge of the losses introduced by the armour....

Prevention of cable fires in nuclear power plants

International Nuclear Information System (INIS)

Murota, George; Yajima, Kazuo

1979-01-01

Nuclear power generation is indispensable to secure required electric power, therefore double or triple safety measures are necessary to prevent serious accidents absolutely. As for the countermeasures to cable fires, interest grew rapidly with the fire in Browns Ferry Power Station in USA in 1975 as the turning point, because multi-strand grouped cables caused to promote the spread of fire. In Japan, also the fire prevention measures for wires and cables were more strengthened, and the measures for preventing the spread of cable fires with the agent preventing the spread of fires have occupied the important position. When multi-strand cables are ignited by some cause, the fire spreads with very large combustion force along wirings to other rooms and installations, and electric systems are broken down. The harmful corrosive gas generated from the burning coating materials of cables diffuses very quickly. In nuclear power stations, the cables which are very hard to burn are adopted, fire prevention sections are established positively, the fire-resisting capability of fire prevention barriers is reviewed, and fire-resisting and smoke-preventing treatments are applied to the parts where cables penetrate walls, floors or ceilings. The paint and the sealing material which prevent the spread of fires are introduced. (Kako, I.)

Loss and Inductance Investigation in Superconducting Cable Conductors

DEFF Research Database (Denmark)

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

1999-01-01

An important parameter in the design and optimization of a superconducting cable conductor is the control of the current distribution among single tapes and layers. This distribution is to a large degree determined by inductances, since the resistances are low. The self and mutual inductances...... of transport current and current distribution.This presentation is based on a number of experiments performed on prototype superconducting cable conductors. The critical current (1uV/cm) of the conductor at 77K was 1590 A (cable #1) and 3240 A (cable #2) respectively.At an rms current of 2 kA (50 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....

Frequency analysis of a tower-cable coupled system

Energy Technology Data Exchange (ETDEWEB)

Park, Moo Yeol [Young Sin Precision Engineering Ltd., Gyungju (Korea, Republic of); Kim, Seock Hyun; Park, In Su [Kangwon National University, Chuncheon (Korea, Republic of); Cui, Chengxun [Yanbian University, Yangji (China)

2013-06-15

This study considers the prediction of natural frequency to avoid resonance in a wind turbine tower- cable coupled system. An analytical model based on the Rayleigh-Ritz method is proposed to predict the resonance frequency of a wind turbine tower structure supported by four guy cables. To verify the validity of the analytical model, a small tower-cable model is manufactured and tested. The frequency and mode data of the tower model are obtained by modal testing and finite element analysis. The validity of the proposed method is verified through the comparison of the frequency analysis results. Finally, using a parametric study with the analytical model, we identified how the cable tension and cable angle affect the resonance frequency of the wind turbine tower structure. From the analysis results, the tension limit and optimal angle of the cable are identified.

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

International Nuclear Information System (INIS)

Wojcicki, F. R.; Negrisoli, M. E. M.; Franco, C. V.

2003-01-01

With the growth of several areas in modern 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/CuSO 4 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. (Author) 8 refs

24 CFR 3285.704 - Telephone and cable TV.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Telephone and cable TV. 3285.704....704 Telephone and cable TV. Refer to § 3285.906 for considerations pertinent to installation of telephone and cable TV. ...

DC to DC power converters and methods of controlling the same

Science.gov (United States)

Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed

2012-12-11

A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

Integrity assessment of grouted posttensioning cables and reinforced concrete of a nuclear containment building

Science.gov (United States)

Philipose, K.; Shenton, B.

2011-04-01

The Containment Buildings of CANDU Nuclear Generating Stations were designed to house nuclear reactors and process equipment and also to provide confinement of releases from a potential nuclear accident such as a Loss Of Coolant Accident (LOCA). To meet this design requirement, a post-tensioning system was designed to induce compressive stresses in the structure to counteract the internal design pressure. The CANDU reactor building at Gentilly-1 (G-1), Quebec, Canada (250 MWe) was built in the early 1970s and is currently in a decommissioned state. The structure at present is under surveillance and monitoring. In the year 2000, a field investigation was conducted as part of a condition assessment and corrosion was detected in some of the grouted post-tension cable strands. However, no further work was done at that time to determine the cause, nature, impact and extent of the corrosion. An investigation of the Gentilly-1 containment building is currently underway to assess the condition of grouted post-tensioning cables and reinforced concrete. At two selected locations, concrete and steel reinforcements were removed from the containment building wall to expose horizontal cables. Individual cable strands and reinforcement bars were instrumented and measurements were taken in-situ before removing them for forensic examination and destructive testing to determine the impact of ageing and corrosion. Concrete samples were also removed and tested in a laboratory. The purpose of the field investigation and laboratory testing, using this structure as a test bed, was also to collect material ageing data and to develop potential Nondestructive Examination (NDE) methods to monitor Containment Building Integrity. The paper describes the field work conducted and the test results obtained for concrete, reinforcement and post-tensioning cables.

Integrity assessment of grouted posttensioning cables and reinforced concrete of a nuclear containment building

Directory of Open Access Journals (Sweden)

Shenton B.

2011-04-01

Full Text Available The Containment Buildings of CANDU Nuclear Generating Stations were designed to house nuclear reactors and process equipment and also to provide confinement of releases from a potential nuclear accident such as a Loss Of Coolant Accident (LOCA. To meet this design requirement, a post-tensioning system was designed to induce compressive stresses in the structure to counteract the internal design pressure. The CANDU reactor building at Gentilly-1 (G-1, Quebec, Canada (250 MWe was built in the early 1970s and is currently in a decommissioned state. The structure at present is under surveillance and monitoring. In the year 2000, a field investigation was conducted as part of a condition assessment and corrosion was detected in some of the grouted post-tension cable strands. However, no further work was done at that time to determine the cause, nature, impact and extent of the corrosion. An investigation of the Gentilly-1 containment building is currently underway to assess the condition of grouted post-tensioning cables and reinforced concrete. At two selected locations, concrete and steel reinforcements were removed from the containment building wall to expose horizontal cables. Individual cable strands and reinforcement bars were instrumented and measurements were taken in-situ before removing them for forensic examination and destructive testing to determine the impact of ageing and corrosion. Concrete samples were also removed and tested in a laboratory. The purpose of the field investigation and laboratory testing, using this structure as a test bed, was also to collect material ageing data and to develop potential Nondestructive Examination (NDE methods to monitor Containment Building Integrity. The paper describes the field work conducted and the test results obtained for concrete, reinforcement and post-tensioning cables.

The optimum spanning catenary cable

Science.gov (United States)

Wang, C. Y.

2015-03-01

A heavy cable spans two points in space. There exists an optimum cable length such that the maximum tension is minimized. If the two end points are at the same level, the optimum length is 1.258 times the distance between the ends. The optimum lengths for end points of different heights are also found.

Seismic Responses of a Cable-Stayed Bridge with Consideration of Uniform Temperature Load

Directory of Open Access Journals (Sweden)

Junjun Guo

2016-12-01

Full Text Available The effects of temperature load on the dynamic responses of cable-stayed bridges have attracted the attention of researchers in recent years. However, these investigations mainly focus on the influence of temperature on the dynamic characteristics of structures, such as vibration mode and frequency. This paper discusses the effects of uniform temperature changes on the seismic responses of a cable-stayed bridge. A three dimensional finite element model of a cable-stayed bridge using OpenSees is established for nonlinear time history analysis, and uniform temperature load is applied to the prototype bridge before the conducting of seismic excitation. Three ground motion records are selected from the PEER strong motion database based on the design spectrum. Case studies are then performed considering the varying temperature and the connections between the deck and pylons of the bridge. The result shows that the seismic responses of the bridge are significantly increased with the consideration of temperature load. Meanwhile, the types between the deck and pylon also have notable impacts on the seismic responses of the bridge with and without temperature changes. This research could provide a reference for designers during the design phase of cable-stayed brides.

Hierarchical Velocity Control Based on Differential Flatness for a DC/DC Buck Converter-DC Motor System

Directory of Open Access Journals (Sweden)

R. Silva-Ortigoza

2014-01-01

Full Text Available This paper presents a hierarchical controller that carries out the angular velocity trajectory tracking task for a DC motor driven by a DC/DC Buck converter. The high level control is related to the DC motor and the low level control is dedicated to the DC/DC Buck converter; both controls are designed via differential flatness. The high level control provides a desired voltage profile for the DC motor to achieve the tracking of a desired angular velocity trajectory. Then, a low level control is designed to ensure that the output voltage of the DC/DC Buck converter tracks the voltage profile imposed by the high level control. In order to experimentally verify the hierarchical controller performance, a DS1104 electronic board from dSPACE and Matlab-Simulink are used. The switched implementation of the hierarchical average controller is accomplished by means of pulse width modulation. Experimental results of the hierarchical controller for the velocity trajectory tracking task show good performance and robustness against the uncertainties associated with different system parameters.

Low Friction Cryostat for HTS Power Cable of Dutch Project

NARCIS (Netherlands)

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

Copper Cable Recycling Technology. Innovative Technology Summary Report

International Nuclear Information System (INIS)

2001-01-01

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

Development of radiation resistant PEEK insulation cable

International Nuclear Information System (INIS)

Mio, Keigo; Ogiwara, Norio; Hikichi, Yusuke; Furukori, Hisayoshi; Arai, Hideyuki; Nishizawa, Daiji; Nishidono, Toshiro

2009-04-01

Material characterization and development has been carried out for cable insulation suitable for use in the J-PARC 3-GeV RCS radiation environment. In spite of its high cost, PEEK (polyether-ether-ketone) has emerged as the leading candidate satisfying requirements of being non-halogen based, highly incombustible and with radiation resistant at least 10 MGy, along with the usual mechanical characteristics such as good elongation at break, which are needed in a cable insulation. Gamma-ray irradiation tests have been done in order to study radiation resistance of PEEK cable. Further, mechanical, electrical and fire retardant characteristics of a complete cable such as would be used at the J-PARC RCS were investigated. As a result, PEEK cables were shown to be not degraded by radiation up to at least 10 MGy, and thus could be expected to operate stably under the 3-GeV RCS radiation environment. (author)

Development of environmental-friendly wire and cable

International Nuclear Information System (INIS)

Ueno, Keiji

1996-01-01

The electron beam technology has been used in many industrial fields as a method of conventional polymer modification or optimum processability. The main industrial fields of radiation crosslinking are wire and cable, heat shrinkable tubings, plastic foams, precuring of tires, floppy disk curing, foods packaging films, and so on. The radiation crosslinking of wire and cable was started in 1961 in Japan and 15 wire and cable companies are now using electron beam accelerators for production or R and D. The dominant characteristics of crosslinking of insulation materials are application at high temperature, good oil and chemical resistibility and high mechanical properties. These radiation crosslinking wire and cable are applied widely in electronics equipments and automobiles. Recently, electronics manufacturers have indicated deep concern over the effects on the environment. Wire and cable also are required to be applicable for environmental preservation. (J.P.N.)

A novel wavelet-based feature extraction from common mode currents for fault location in a residential DC microgrid

DEFF Research Database (Denmark)

Beheshtaein, Siavash; Yu, Junyang; Cuzner, Rob

2017-01-01

approaches have been developed that enable construction of scalable microgrids based on PV and battery storage. However, as these systems proliferate, it will be necessary to develop safe and reliable methods for fault protection. Ground faults are of specific concern because, in many cases, cables...... are buried underground. At the same time, microgrids include current monitoring and processing capability wherever an energy resource interfaces to the microgrid through a power electronic converter. This paper discusses methods for identifying ground fault behavior within standard DC microgrid structures...

Defying c-Abl signaling circuits through small allosteric compounds

Directory of Open Access Journals (Sweden)

Stefania eGonfloni

2014-11-01

Full Text Available Many extracellular and intracellular signals promote the c-Abl tyrosine kinase activity. c-Abl in turn triggers a multitude of changes either in protein phosphorylation or in gene expression in the cell. Yet, c-Abl takes part in diverse signaling routes because of several domains linked to its catalytic core. Complex conformational changes turn on and off its kinase activity. These changes affect surface features of the c-Abl kinase and likely its capability to bind actin and/or DNA. Two specific inhibitors (ATP-competitive or allosteric compounds regulate the c-Abl kinase through different mechanisms. NMR studies show that a c-Abl fragment (SH3-SH2-linker-SH1 adopts different conformational states upon binding to each inhibitor. This supports an unconventional use for allosteric compounds to unraveling physiological c-Abl signaling circuits.

Method of exchanging cables of neutron monitoring instrumentation tube and folding device of the cable

International Nuclear Information System (INIS)

Sakamaki, Kazuo.

1990-01-01

In a BWR type reactor, a wide range monitor (WRNM) is used instead of a conventional neutron source range monitor (SRM) or an intermediate range monitor (IRM). The WRNM is always fixed to a predetermined position in a reactor core while containing a detection section in a dry tube, different from a conventional monitor. Accordingly, driving devices for the conventional detection section such as in SRM and IRM are not necessary but, when the reactor is operated for a long period of time, it is sometimes necessary to be replaced with new WRNM. According to the present invention, the cable of the detector placed in a neutron instrumentation tube is connected to a cable take-up drum in a take-up device passing through a cask. Then, the cable is taken-up by driving the take-up drum by a driving motor and the WRNM detection section attached to the top end of the cable is contained in the cask. With this constitution, replacing and processing operation for the detection section can be facilitated and operator's exposure dose can be reduced. (I.S.)

An Integrated Multifunctional Bidirectional AC/DC and DC/DC Converter for Electric Vehicles Applications

OpenAIRE

Liwen Pan; Chengning Zhang

2016-01-01

This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs). The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for m...

30 CFR 75.804 - Underground high-voltage cables.

Science.gov (United States)

2010-07-01

... 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 resistance... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground high-voltage cables. 75.804 Section...

PENGGUNAAN FUZZY LOGIC UNTUK KONTROL PARALLEL CONVERTER DC-DC

Directory of Open Access Journals (Sweden)

Bambang Prio Hartono

2012-09-01

Full Text Available Abstract: Using system fuzzy logic as control  technology have been used on low load dc-dc converter with combined parallel compiled  dc-dc converter can  obtain big load.   With existence of differrence of component parameter and each parallel compiled converter can obtained different current  and voltage output.  Function of controller  for to do adjustment, so that current which is applied  to  load by each converter  can be obtained  difference error as small as possible or same. The object of research is developing design of large signal dc-dc converter which is  combined with using  FLC so that  obtain  better performance.  To get better performance have been made plant model and simulation with CDE method.  The more systematic  system and design is needed to overcome bigger load  on dc-dc converter, so that parallel  compiled current master slave control system on dc-dc converter with using fuzzy logic  controller is used. Result of  research showed that error or difference of  current  which is applied to load can handled by fuzzy logic  controller.  Technic of current and voltage controller co to do adjustment current and voltage distribution  equally to load.  Distribution of iL1,iL2 and  output voltage Vo on dc-dc  converter with load 2,25 until  7,875 and voltage  100  until 120 volt,  load current beetwen  12 until 48, % relatif  error  Vo  0,4% until  0,9%.

Crystal River 3 Cable Materials for Thermal and Gamma Radiation Aging

Energy Technology Data Exchange (ETDEWEB)

Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Correa, Miguel [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zwoster, Andy [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-09-07

The Expanded Materials Degradation Assessment Volume 5: Aging of Cables and Cable Systems (EMDA) summarizes the state of knowledge of materials, constructions, operating environments, and aging behavior of low voltage and medium cables in nuclear power plants (NPPs) and identifies potential knowledge gaps with regard to cable operation beyond 60 years. The greatest area of uncertainty relates to how well the accelerated aging used in the original equipment qualification (EQ) processes predicts the performance of cable materials in extended operation. General opinion and utility experience have indicated that actual operating environments of in-plant cables are not as severe, however, as the operating and design basis environments used in the qualification process. Better understanding of the long term aging behavior of cable insulation materials in service conditions and the analysis of actual cable operating environments are the objectives of ongoing research to support subsequent license renewal activities in particular and long term cable aging management in general. A key component of the effort to better understand cable material aging behavior is the availability of representative samples of cables that have been installed in operating light water reactors and have experienced long term service. Unique access to long term service cables, including relatively rich information on cable identity and history, occurred in 2016 through the assistance of the Electric Power Research Institute (EPRI). EPRI facilitated DOE receipt of harvested cables from the decommissioned Crystal River Unit 3 (CR3) pressurized water reactor representing six of the nine most common low voltage cable manufacturers (EPRI 103841R1): Rockbestos, Anaconda Wire and Cable Company (Anaconda), Boston Insulated Wire (BIW), Brand-Rex, Kerite and Okonite. Cable samples received had been installed in the operating plant for durations ranging from 10 years to 36 years. These cables provide the

Rapid optimization of tension distribution for cable-driven parallel manipulators with redundant cables

Science.gov (United States)

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.

Thin film conductors for self-equalizing cables

Science.gov (United States)

Owen, G.; Trutna, W. R.; Orsley, T. J.; Lucia, F.; Daly, C. B.

2017-10-01

Self-equalizing cables using hollow conductors with wall thickness less than the skin depth were proposed in 1929. However, they do not appear ever to have been widely used, although the idea has resurfaced and been refined from time to time. In the early 2000's, self-equalizing conductors consisting of solid magnetic steel cores coated with silver were developed by W.L. Gore, and used in their 2.5 Gb/s "Eye-Opener" cables, although higher speed versions never appeared. We have revived the original 1929 idea, proposing to use glass as a solid insulating core. This technology can potentially work at frequencies of many 10's of GHz. Possible uses include short range GHz links such as USB and Thunderbolt, and intra-rack interconnections in data centers. Our feasibility experiments have validated the principle. Copper coated glass fibers can, in principle, be manufactured, but in these tests, the conductors were capillaries internally coated with silver as these are easily obtainable, relatively inexpensive and serve to test the concept. The performance of these experimental twin lead cables corresponds to calculations, confirming the general principle. By calculation, we have compared the performance of cables made from copper-on-insulator conductors to that of similar cables made with solid copper conductors, and verified that copper-on-insulator cables have significantly less frequency dependent loss. We have also made and tested cables with copper on PEEK conductors as surrogates for copper on glass fiber.

Modeling Cable and Guide Channel Interaction in a High-Strength Cable-Driven Continuum Manipulator.

Science.gov (United States)

Moses, Matthew S; Murphy, Ryan J; Kutzer, Michael D M; Armand, Mehran

2015-12-01

This paper presents several mechanical models of a high-strength cable-driven dexterous manipulator designed for surgical procedures. A stiffness model is presented that distinguishes between contributions from the cables and the backbone. A physics-based model incorporating cable friction is developed and its predictions are compared with experimental data. The data show that under high tension and high curvature, the shape of the manipulator deviates significantly from a circular arc. However, simple parametric models can fit the shape with good accuracy. The motivating application for this study is to develop a model so that shape can be predicted using easily measured quantities such as tension, so that real-time navigation may be performed, especially in minimally-invasive surgical procedures, while reducing the need for hazardous imaging methods such as fluoroscopy.

Efficient Statistical Extraction of the Per-Unit-Length Capacitance and Inductance Matrices of Cables with Random Parameters

Directory of Open Access Journals (Sweden)

P. Manfredi

2015-05-01

Full Text Available Cable bundles often exhibit random parameter variations due to uncertain or uncontrollable physical properties and wire positioning. Efficient tools, based on the so-called polynomial chaos, exist to rapidly assess the impact of such variations on the per-unit-length capacitance and inductance matrices, and on the pertinent cable response. Nevertheless, the state-of-the-art method for the statistical extraction of the per-unit-length capacitance and inductance matrices of cables suffers from several inefficiencies that hinder its applicability to large problems, in terms of number of random parameters and/or conductors. This paper presents an improved methodology that overcomes the aforementioned limitations by exploiting a recently-published, alternative approach to generate the pertinent polynomial chaos system of equations. A sparse and decoupled system is obtained that provides remarkable benefits in terms of speed, memory consumption and problem size that can be dealt with. The technique is thoroughly validated through the statistical analysis of two canonical structures, i.e. a ribbon cable and a shielded cable with random geometry and position.

Full range ZVS DC-DC converter

International Nuclear Information System (INIS)

Upadhyay, Rinki; Badapanda, M.K.; Hannurkar, P.R.

2011-01-01

A 500 V, 24 Amp DC-DC converter with digital signal processor (DSP) based control and protection has been designed, fabricated and tested. Its power circuit consists of IGBT based single phase inverter bridge, ferrite transformer and diode rectifier. All IGBTs in the inverter bridge are operated in zero voltage switching (ZVS) mode to minimize switching losses thereby increasing the efficiency of the converter significantly. The efficiency of this converter is measured to be greater than 97% at full load. In a conventional full bridge inverter, typically ZVS is achieved under full load condition while at light load ZVS is lost. An auxiliary LC circuit has been intentionally incorporated in this converter to achieve ZVS even at light loaded conditions. Detailed simulation of the converter circuit is carried out and crucial waveforms have been presented in this paper. Microchip make dsPIC30F2020 DSP is employed to provide phase shifted PWMs to IGBTs in the inverter bridge. All the crucial parameters are also monitored by this DSP and in case of any unfavorable conditions, the converter is tripped off. Suitable experiments were carried out in this DC-DC converter under different loaded conditions and a close match between the simulated and experimental results were obtained. Such DC-DC converters can be connected in series or parallel for the development of solid state modular power supplies for various applications. (author)

Debris from cobalt-chrome cable may cause acetabular loosening.

Science.gov (United States)

Kelley, S S; Johnston, R C

1992-12-01

To address the issue of nonunion with trochanteric osteotomy, surgeons have experimented with various modes of fixation, wire and cable being the two most popular. From a group of 643 primary cemented total hip arthroplasties performed by a single surgeon via the trans-trochanteric approach, minimum four-year roentgenographic follow-up evaluations were performed on 322 hips (50%). The method of fixation was stainless steel monofilament wire in 162 cases and Co-Cr cable in 160. Trochanteric union rates were 75% (122 patients) for the wire group and 79% (126 patients) for the cable. Breakage rates of the entire trochanteric fixation construction (all three wires or cables) were 43% (68 patients) for the wire and 12% (20 patients) for the cable. Unraveled cable was seen in 56% of the hips (90 patients), and in 47% of these hips, there were no broken cables. Blinded roentgenographic analysis of the acetabulum, preformed independently, revealed that loosening of the acetabulum in the cable group was greater than in the wire group. Cables offer no significant benefit over wires and may have potential adverse effects. Generation of significant particulate debris was noted roentgenographically, and marked reaction/destruction was found at the time of revision surgery.

Fault Management of a Cold Dielectric HTS Power Transmission Cable

International Nuclear Information System (INIS)

Maguire, J; Allais, A; Yuan, J; Schmidt, F; Hamber, F; Welsh, Tom

2006-01-01

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

Improved practical formulas for estimation of cable tension by vibration method; Shindoho ni yoru cable choryoku jitsuyo santeishiki no hosei

Energy Technology Data Exchange (ETDEWEB)

Zui, H. [Setsunan University, Osaka (Japan). Faculty of Engineering; Shinke, T. [Kobe Technical College, Kobe, Kobe (Japan); Hamazaki, Y. [Kobe Steel, Ltd., Kobe (Japan)

1995-10-21

The vibration method is usually utilized on the measurement of cable tension during construction of cable bridge such as Nielsen bridges or cable stayed bridges. Practical formula for the vibration method previously proposed by authors is often used where bending rigidity is taken into account. These formula, however, have a certain limit of application and do not yield good results when the cable is not slender or not enough mentioned. The practical formula is modified to improve the accuracy and new formulas are made. The new practical formulas are applicable to any cables, regardless of its length and tension in it. The accuracy is confirmed through comparison of the value obtained by practical formulas with measured values and calculated value by F.E.M. 2 refs., 4 figs., 1 tab.

30 CFR 75.600 - Trailing cables; flame resistance.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Trailing cables; flame resistance. 75.600 Section 75.600 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... cables; flame resistance. [Statutory Provisions] Trailing cables used in coal mines shall meet the...

Dynamic characteristics of stay cables with inerter dampers

Science.gov (United States)

Shi, Xiang; Zhu, Songye

2018-06-01

This study systematically investigates the dynamic characteristics of a stay cable with an inerter damper installed close to one end of a cable. The interest in applying inerter dampers to stay cables is partially inspired by the superior damping performance of negative stiffness dampers in the same application. A comprehensive parametric study on two major parameters, namely, inertance and damping coefficients, are conducted using analytical and numerical approaches. An inerter damper can be optimized for one vibration mode of a stay cable by generating identical wave numbers in two adjacent modes. An optimal design approach is proposed for inerter dampers installed on stay cables. The corresponding optimal inertance and damping coefficients are summarized for different damper locations and interested modes. Inerter dampers can offer better damping performance than conventional viscous dampers for the target mode of a stay cable that requires optimization. However, additional damping ratios in other vibration modes through inerter damper are relatively limited.

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

Directory of Open Access Journals (Sweden)

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

TOPOLOGICAL REVIEW AND ANALYSIS OF DC-DC BOOST CONVERTERS

Directory of Open Access Journals (Sweden)

V. INDRA GANDHI

2017-06-01

Full Text Available DC voltage boost up is essential in numerous applications; especially considering Photovoltaic (PV based renewable power generation system. The conventional DC-DC boost converter is the most admired configuration for this scheme, even if the converter efficiency is restricted at duty cycle near to maximum value. In order to find solution to the problem and improve its conversion capability, many converter configurations have been implemented so far. With this circumstance, this research work proposes to give overview of a few most imperative research works related to DC-DC boost converters. Some configurations are covered and classified basically based on the application. The major benefits and disadvantages related to the available techniques are also briefly conveyed. At last, a proper evaluation is recognized among the important types of DC-DC boost converters in terms of efficiency, number of components, and stability.

2nd International Conference on Cable-Driven Parallel Robots

CERN Document Server

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

Fiscal 1997 report on the results of the international standardization R and D. Development of a test method of halogen-free flame-retardant cables and a study of the cable standards; 1997 nendo seika hokokusho kokusai hyojun soseigata kenkyu kaihatsu. Non halogen nannen cable no shiken hoho kaihatsu narabini cable kikaku no kento

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

As for halogen-free flame-retardant cables with high recyclability and safety (HFFR cables), the development is being promoted in many countries as a next generation cable. The standard of HFFR cables has been set up by some countries and groups in the U.S. and Europe, but the international standard has not yet been established independently. The purpose of this R and D is the development of a test method to appropriately evaluate the performance of HFFR cables and its standardization, and the proposal of the international standardization on common items of the cable standard. A study group was sent to the U.S. and Europe to investigate the development, application status and test methods of the HFFR cable overseas. The ion chromatography and FT-IR method were studied as methods to evaluate corrosivity/toxicity of the gases emitted in combustion. The performance of HFFR cables in Japan and abroad was also evaluated mainly by IEC standards. Further, considering the results of the overseas surveys, the structure and details of the international standard plan on HFFR cables were studied, and approaches to the international standardization were studied. 32 refs., 31 figs., 54 tabs.

Fiscal 1999 research result report on energy and environment technology demonstration research support project (International joint demonstration research project). Improvement of long-distant power transmission efficiency and reliability, and its environmental impact assessment; 1999 nendo chokyori soden hoshiki ni kansuru soden koritsu to soden shinraido no kojo oyobi kankyo eno eikyo hyoka seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Japan-Russia international joint research was made on overhead ultrahigh-voltage DC power transmission lines for transmission loss reduction and reliability improvement, and an optimum international power supply cable system, considering energy saving and environment conservation. Using the European-Russian DC power transmission line of {+-}500kV and 4GW as a model, comparison was made between a model using Russian round strands and glass insulators and a model using Japanese low-loss wires and insulators. As for improvement of the reliability in cold districts, Russian design techniques for tower structure and ice loading were reasonable to counteract galloping oscillation and ice load. In evaluation and selection of optimum underground and marine cables, study was made on cable specifications using the Turkey-Russia power transmission route as a model. The environmental assessment result of these cables showed that XLPE cable under development is optimum. (NEDO)

Analysis of impact of “strong DC and weak AC” on receiving-end power system

Science.gov (United States)

Wang, Qiang; Li, Tianran; Yang, Pengcheng

2018-02-01

The rapid development of UHVDC transmission project has brought abundant power supply to the receiving-end power system area, but also many security and stability problems. This paper summarizes four elements that affect the strength of AC system, and then simulates the most basic two-terminal single-pole UHV transmission system by MATLAB/Simulink. It analyses the impact of receiving-end AC power system strength on real-time power, frequency and voltage. Finally, in view of operation risk of “strong DC and weak AC”, this paper puts forward three countermeasures.

Stationary operational behavior unsymmetrical superconducting three-phase cable

Energy Technology Data Exchange (ETDEWEB)

Iser, R.

1974-01-01

A superconducting cable with a coaxial conductor arrangement is electrically unsymmetrical. Voltage and current relationships are analyzed for such a cable where, as a result of reactance and capacitance matrices being unsymmetric, large voltage unsymmetry appears. This limits the practical length of this type of cable. It is shown that a significant gain in symmetry is attained by the use of two cables connected in parallel. The compensating current which then occurs involves no disadvantage. The circuit described permits overloads of up to 100 percent.

Influence of Icing on Bridge Cable Aerodynamics

DEFF Research Database (Denmark)

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

2013-01-01

In recent years the relevance of ice accretion for wind-induced vibration of structural bridge cables has been recognised and became a subject of research in bridge engineering. Full-scale monitoring and observation indicate that light precipitation at moderate low temperatures between zero and -5......°C may lead to large amplitude vibrations of bridge cables under wind action. For the prediction of aerodynamic instability quasi-steady models have been developed estimating the cable response magnitude based on structural properties and aerodynamic force coefficients for drag, lift and torsion...... forces of different bridge cables types. The experiments were conducted in a wind tunnel facility capable amongst others to simulate incloud icing conditions....

Rotator cuff tendon connections with the rotator cable.

Science.gov (United States)

Rahu, Madis; Kolts, Ivo; Põldoja, Elle; Kask, Kristo

2017-07-01

The literature currently contains no descriptions of the rotator cuff tendons, which also describes in relation to the presence and characteristics of the rotator cable (anatomically known as the ligamentum semicirculare humeri). The aim of the current study was to elucidate the detailed anatomy of the rotator cuff tendons in association with the rotator cable. Anatomic dissection was performed on 21 fresh-frozen shoulder specimens with an average age of 68 years. The rotator cuff tendons were dissected from each other and from the glenohumeral joint capsule, and the superior glenohumeral, coracohumeral, coracoglenoidal and semicircular (rotator cable) ligaments were dissected. Dissection was performed layer by layer and from the bursal side to the joint. All ligaments and tendons were dissected in fine detail. The rotator cable was found in all specimens. It was tightly connected to the supraspinatus (SSP) tendon, which was partly covered by the infraspinatus (ISP) tendon. The posterior insertion area of the rotator cable was located in the region between the middle and inferior facets of the greater tubercle of the humerus insertion areas for the teres minor (TM), and ISP tendons were also present and fibres from the SSP extended through the rotator cable to those areas. The connection between the rotator cable and rotator cuff tendons is tight and confirms the suspension bridge theory for rotator cuff tears in most areas between the SSP tendons and rotator cable. In its posterior insertion area, the rotator cable is a connecting structure between the TM, ISP and SSP tendons. These findings might explain why some patients with relatively large rotator cuff tears can maintain seamless shoulder function.

Automated wireless monitoring system for cable tension using smart sensors

Science.gov (United States)

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.

Solid-cryogen-stabilized, cable-in-conduit (CIC) superconducting cables

Science.gov (United States)

Voccio, J. P.; Michael, P. C.; Bromberg, L.; Hahn, S.

2015-12-01

This paper considers the use of a solid cryogen as a means to stabilize, both mechanically and thermally, magnesium diboride (MgB2) superconducting strands within a dual-channel cable-in-conduit (CIC) cable for use in AC applications, such as a generator stator winding. The cable consists of two separate channels; the outer channel contains the superconducting strands and is filled with a fluid (liquid or gas) that becomes solid at the device operating temperature. Several options for fluid will be presented, such as liquid nitrogen, hydrocarbons and other chlorofluorocarbons (CFCs) that have a range of melting temperatures and volumetric expansions (from solid at operating temperature to fixed volume at room temperature). Implications for quench protection and conductor stability, enhanced through direct contact with the solid cryogen, which has high heat capacity and thermal conductivity (compared with helium gas), will be presented. Depending on the cryogen, the conductor will be filled initially either with liquid at atmospheric conditions or a gas at high pressure (∼100 atm). After cooldown, the cryogen in the stranded-channel will be solid, essentially locking the strands in place, preventing strand motion and degradation due to mechanical deformation while providing enhanced thermal capacity for stability and protection. The effect of cryogen porosity is also considered. The relatively high heat capacity of solid cryogens at these lower temperatures (compared to gaseous helium) enhances the thermal stability of the winding. During operation, coolant flow through the open inner channel will minimize pressure drop.

Analysis of the Working Cable System of Single-span Circulating Ropeway

Directory of Open Access Journals (Sweden)

Qin Jian

2017-01-01

Full Text Available Based on the analysis of the mutual interaction between bearing cable and traction cable of single-span circulating ropeway, the calculation method is proposed for working cables of ropeway with arbitrary loads. The 5 sets nonlinear equations are set up for the working cables according to the equal spans and altitude differences of the bearing cable and the traction cable, the constant of the load running space and the bearing cable length, and the tension balance of bearing cable and traction cable beside load. The resolving method is proposed based on the Newton iterative method. The correctness and feasibility of the method are proved by the results of engineering test. From the solution, the tension and coordinate of working cables can be obtained accurately, which is meaningful for the design and analysis of the freight ropeway.

DC/DC converters for integration of double-layer condensers in onboard power supply; DC/DC-Wandler zur Einbindung von Doppelschichtkondensatoren in das Fahrzeugenergiebordnetz

Energy Technology Data Exchange (ETDEWEB)

Polenov, Dieter

2010-01-15

The paper discusses DC/DC converters for integration of double layer condensers into the onboard power system. First, requirements on DC/DC converters are listed and compared on the basis of three exemplary applications. A DC/DC converter concept is developed for decoupling transient high-power loads like electric steering systems. Three different topologies are compared using a specially developed method in order to find the best solution for the given application. In order to establish adequate criteria for selecting the switching frequency and inductivities of storage throttles, the influence of the trottle power change on the switching characteristics of the MOSFETs and on certain ranges of EMP interference emissions is investigated. As methods of optimising the operation of the synchronous rectifiers, parallel connection of Schottky diodes and synchronous rectifiers as well as the variation of the shut-off dead times of synchronous rectifiers were investigated. Further, a concept for converter control was developed in consideration of the intended application and topology. Finally, selected aspects for implementation of the DC/DC converter concept are presented as well as the results of experimental investigations.

Long-term monitoring FBG-based cable load sensor

Science.gov (United States)

Zhang, Zhichun; Zhou, Zhi; Wang, Chuan; Ou, Jinping

2006-03-01

Stay cables are the main load-bearing components of stayed-cable bridges. The cables stress status is an important factor to the stayed-cable bridge structure safety evaluation. So it's very important not only to the bridge construction, but also to the long-term safety evaluation for the bridge structure in-service. The accurate measurement for cable load depends on an effective sensor, especially to meet the long time durability and measurement demand. FBG, for its great advantage of corrosion resistance, absolute measurement, high accuracy, electro-magnetic resistance, quasi-distribution sensing, absolute measurement and so on, is the most promising sensor, which can cater for the cable force monitoring. In this paper, a load sensor has been developed, which is made up of a bushing elastic supporting body, 4 FBGs uniformly-spaced attached outside of the bushing supporting body, and a temperature compensation FBG for other four FBGs, moreover a cover for protection of FBGs. Firstly, the sensor measuring principle is analyzed, and relationship equation of FBG wavelength shifts and extrinsic load has also been gotten. And then the sensor calibration experiments of a steel cable stretching test with the FBG load sensor and a reference electric pressure sensor is finished, and the results shows excellent linearity of extrinsic load and FBG wavelength shifts, and good repeatability, which indicates that such kind of FBG-based load sensor is suitable for load measurement, especially for long-term, real time monitoring of stay-cables.

Heat resistant wire and cable and heat shrinkable tubes

Energy Technology Data Exchange (ETDEWEB)

Ueno, Keiji [Sumitomo Electric Industries Ltd. (Japan)

1994-12-31

Radiation processes have been used in industrial fields (e.g. wire and cable, heat shrinkable tubes) for about 30 years. In Japan, 60 electron beam accelerators were used in R and D, 54 in wire and cable, 24 in tire rubber, 16 in paint curing, 14 in PE foam and 9 accelerators were used in heat shrinkable tubes in 1993. Many properties (e.g. solder resistance, thermal deformation, and solven resistance) of wire and cable are improved by using radiation processes, and many kinds of radiation crosslinked wire and cable are used in the consumer market (TV sets, VTR`s, audio disc players, etc.), automobiles (automobile wire harnesses, fusible link wires, sensor cables etc.), and the industrial market (computer cables, cables for keyboards, coaxial cables, etc.). Another important industrial application of E{beta} radiation process is heat shrinkable tubes. Heat shinkable tubes, heated by a hot gun, shrink 1/2 {approx} 1/3 of their inner diameters. Heat shrinkable tubes are used for covers of distributing line terminals, joint covers of telecommunication lines, protection of fuel pipe lines and so on. In this seminar, actual applications and characteristic properties of radiation crosslinked materials are presented.

Heat resistant wire and cable and heat shrinkable tubes

International Nuclear Information System (INIS)

Keiji Ueno

1994-01-01

Radiation processes have been used in industrial fields (e.g. wire and cable, heat shrinkable tubes) for about 30 years. In Japan, 60 electron beam accelerators were used in R and D, 54 in wire and cable, 24 in tire rubber, 16 in paint curing, 14 in PE foam and 9 accelerators were used in heat shrinkable tubes in 1993. Many properties (e.g. solder resistance, thermal deformation, and solven resistance) of wire and cable are improved by using radiation processes, and many kinds of radiation crosslinked wire and cable are used in the consumer market (TV sets, VTR's, audio disc players, etc.), automobiles (automobile wire harnesses, fusible link wires, sensor cables etc.), and the industrial market (computer cables, cables for keyboards, coaxial cables, etc.). Another important industrial application of Eβ radiation process is heat shrinkable tubes. Heat shinkable tubes, heated by a hot gun, shrink 1/2 ∼ 1/3 of their inner diameters. Heat shrinkable tubes are used for covers of distributing line terminals, joint covers of telecommunication lines, protection of fuel pipe lines and so on. In this seminar, actual applications and characteristic properties of radiation crosslinked materials are presented

Analysis of Harmonic Vibration of Cable-Stayed Footbridge under the Influence of Changes of the Cables Tension

Directory of Open Access Journals (Sweden)

Pakos Wojciech

2015-09-01

Full Text Available The paper presents numerical analysis of harmonically excited vibration of a cable-stayed footbridge caused by a load function simulating crouching (squats while changing the static tension in chosen cables. The intentional synchronized motion (e.g., squats of a single person or group of persons on the footbridge with a frequency close to the natural frequency of the structure may lead to the resonant vibrations with large amplitudes. The appropriate tension changes in some cables cause detuning of resonance on account of stiffness changes of structures and hence detuning in the natural frequency that is close to the excitation frequency. The research was carried out on a 3D computer model of a real structure - a cable-stayed steel footbridge in Leśnica, a quarter of Wrocław, Poland, with the help of standard computer software based on FEM COSMOS/M System.

Analysis of Harmonic Vibration of Cable-Stayed Footbridge under the Influence of Changes of the Cables Tension

Science.gov (United States)

Pakos, Wojciech

2015-09-01

The paper presents numerical analysis of harmonically excited vibration of a cable-stayed footbridge caused by a load function simulating crouching (squats) while changing the static tension in chosen cables. The intentional synchronized motion (e.g., squats) of a single person or group of persons on the footbridge with a frequency close to the natural frequency of the structure may lead to the resonant vibrations with large amplitudes. The appropriate tension changes in some cables cause detuning of resonance on account of stiffness changes of structures and hence detuning in the natural frequency that is close to the excitation frequency. The research was carried out on a 3D computer model of a real structure - a cable-stayed steel footbridge in Leśnica, a quarter of Wrocław, Poland, with the help of standard computer software based on FEM COSMOS/M System.

Thin film conductors for self-equalizing cables

Directory of Open Access Journals (Sweden)

G. Owen

2017-10-01

Full Text Available Self-equalizing cables using hollow conductors with wall thickness less than the skin depth were proposed in 1929. However, they do not appear ever to have been widely used, although the idea has resurfaced and been refined from time to time. In the early 2000’s, self-equalizing conductors consisting of solid magnetic steel cores coated with silver were developed by W.L. Gore, and used in their 2.5 Gb/s “Eye-Opener” cables, although higher speed versions never appeared. We have revived the original 1929 idea, proposing to use glass as a solid insulating core. This technology can potentially work at frequencies of many 10’s of GHz. Possible uses include short range GHz links such as USB and Thunderbolt, and intra-rack interconnections in data centers. Our feasibility experiments have validated the principle. Copper coated glass fibers can, in principle, be manufactured, but in these tests, the conductors were capillaries internally coated with silver as these are easily obtainable, relatively inexpensive and serve to test the concept. The performance of these experimental twin lead cables corresponds to calculations, confirming the general principle. By calculation, we have compared the performance of cables made from copper-on-insulator conductors to that of similar cables made with solid copper conductors, and verified that copper-on-insulator cables have significantly less frequency dependent loss. We have also made and tested cables with copper on PEEK conductors as surrogates for copper on glass fiber.

Chaos analysis and chaotic EMI suppression of DC-DC converters

CERN Document Server

Zhang, Bo

2014-01-01

Introduces chaos theory, its analytical methods and the means to apply chaos to the switching power supply design DC-DC converters are typical switching systems which have plenty of nonlinear behaviors, such as bifurcation and chaos. The nonlinear behaviors of DC-DC converters have been studied heavily over the past 20 years, yet researchers are still unsure of the practical application of bifurcations and chaos in switching converters. The electromagnetic interference (EMI), which resulted from the high rates of changes of voltage and current, has become a major design criterion in DC-DC co

Fabrication of Nb3Sn cables for ITER toroidal field coils

International Nuclear Information System (INIS)

Isono, Takaaki; Tsutsumi, Fumiaki; Nunoya, Yoshihiko; Matsui, Kunihiro; Takahashi, Yoshikazu; Nakajima, Hideo; Ishibashi, Tatsuji; Sato, Go; Chida, Kenji; Suzuki, Rikio; Tanji, Tsutomu

2012-01-01

Cable-in-conduit conductors for ITER toroidal field (TF) coils will be operated at 68 kA and 11.8 T. The cable is composed of 1,422 strands with a diameter of 0.82 mm. There were two options for initial procurement. For option 2, the twist pitches at lower stages are longer than in option 1. Trials were performed to assess the feasibility of these options. In the trials for option 1, the nominal outer diameter of sub-cables and reduction schedule of final cables were evaluated and finalized. In the trials for option 2, problems were encountered at the third stage cabling. These problems were resolved through increasing the die size in that stage and improving the tension balance of the second-stage cables to reduce friction between the die and the cable, and also through avoiding loose twisting at both edges of the third cables. Option 2 was finally selected in 2009 based on superconducting performance enhancement of the cable. After the qualification of the fabrication procedure using fabrication of a 760-m dummy cable and a 415-m superconducting cable, mass production of the cables started in March 2010. (author)

What should your DC default be?

NARCIS (Netherlands)

Cui, J.

2009-01-01

As reported, most DC pension scheme participants simply follow proposed defaults, even though they have the freedom to choose. Consequently, default designs have dramatic impacts on individuals’retirement saving outcomes. Given the fact that the default design matters, this paper evaluates

46 CFR 111.60-6 - Fiber optic cable.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Fiber optic cable. 111.60-6 Section 111.60-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-6 Fiber optic cable. Each fiber optic cable must— (a) Be...

Comparison of programmed and cabled re-entrance systems. Elaboration of cabled re-entrance system for a CII 90.40

International Nuclear Information System (INIS)

Perraudeau, Jean

1976-01-01

The objective of this research thesis is to study problems related to re-entrance, and, more particularly, to study a re-entrance system for a CII 90.40 computer. Such a system can be realised under a programmed or cabled form, and both approaches are described and compared. A generalisation of this comparison is briefly proposed. As the computer already possesses a programmed re-entrance system, the author focuses on the study of the cabled re-entrance system which results in an improvement of performance and possibilities provided by this computer, particularly for its use in real time. The design, realisation and development of such a cabled system are reported. A first part reports a theoretical study on re-entrance (definition, problems, applications), a presentation of the computer, a description of the programmed re-entrance system, a presentation of the principle of the chosen cabled re-entrance system, a definition of the structure and operating mode of the cabled pile and a description of its various components, and a flowchart analysis of function execution. The second part reports the practical realisation: definition, technological overview, technology used in the cabled pile, sequencing and multiplexing principle, impulse transmission, logical layouts, and circuit adjustments. The third part presents practical example. An assessment and perspectives are finally discussed

Full wave dc-to-dc converter using energy storage transformers

Science.gov (United States)

Moore, E. T.; Wilson, T. G.

1969-01-01

Full wave dc-to-dc converter, for an ion thrustor, uses energy storage transformers to provide a method of dc-to-dc conversion and regulation. The converter has a high degree of physical simplicity, is lightweight and has high efficiency.

Pulsewidth modulated DC-to-DC power conversion circuits, dynamics, and control designs

CERN Document Server

Choi, Byungcho

2013-01-01

This is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to

Intermodal resonance of vibrating suspended cables

NARCIS (Netherlands)

Rienstra, S.W.

2010-01-01

The weakly nonlinear free vibrations of a single suspended cable, or a coupled system of suspended cables, may be classified as gravity modes (no tension variations to leading order) and elasto-gravity modes (tension and vertical displacement equally important). It was found earlier [12] that the

Young's moduli of cables for high field superconductive dipole magnet

International Nuclear Information System (INIS)

Yamada, Shunji; Shintomi, Takakazu.

1983-01-01

Superconductive dipole magnets for big accelerators are subjected to enormous electro-magnetic force, when they are operated with high field such as 10 Tesla. They should be constructed by means of superconductive cables, which have high Young's modulus, to obtain good performance. To develop such cables we measured the Young's moduli of cables for practical use of accelerator magnets. They are monolithic and compacted strand cables. We measured also Young's moduli of monolithic copper and brass cables for comparison. The obtained data showed the Young's moduli of 35 and 15 GPa for the monolithic and compacted strand cables, respectively. (author)

Leaky coaxial cable signal transmission for remote facilities

Science.gov (United States)

Smith, S. F.; Crutcher, R. I.

To develop reliable communications methods to meet the rigorous requirements for nuclear hot cells and similar environments, including control of cranes, transporters, and advanced servomanipulators, the Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) has conducted extensive tests of numerous technologies to determine their applicability to remote operations. To alleviate the need for large bundles of cables that must accommodate crane/transporter motion relative to the boundaries of the cell, several transmission techniques are available, including slotted-line radio-frequency couplers, infrared beams, fiber-optic cables, free-space microwave, and inductively coupled leaky coaxial cable. This paper discusses the general characteristics, mode of operation, and proposed implementation of leaky coaxial cable technology in a waste-handling facility scheduled to be built in the near future at ORNL. In addition, specific system hardware based around the use of leaky coaxial cable is described in detail. Finally, data from a series of radiation exposure tests conducted by the CFRP on several samples of the basic leaky coaxial cable and associated connectors are presented.

Device for guiding various diameter size cable

Energy Technology Data Exchange (ETDEWEB)

Litvinov, I.M.; Klauzer, L.P.; Yeganov, L.I.; Zaripov, A.M.

1982-01-30

A design is submitted for a device to guide cable of various diameters. This device consists of a profiled multiple-pass roller, and clamps for uniting cut cable. This design is simplified by allowing both the rollers and their supports to rotate on the roller axis thus facilitating interaction with the clamps. The working surface of the supports is evolute while the outside surfaces have screw-channels for transfering the cable from one roller pass to the other.

30 CFR 75.601 - Short circuit protection of trailing cables.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection of trailing cables. 75... MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Trailing Cables § 75.601 Short circuit protection of trailing cables. [Statutory Provisions] Short circuit protection for trailing cables...

Power plant cable condition monitoring and testing at Georgia Power

International Nuclear Information System (INIS)

Champion, T.C.

1988-01-01

Georgia Power's Research Center has been heavily involved in the evaluation of electrical insulating materials and cables since its inception more than 17 years ago. For the past ten years that expertise has been applied to cables used in generation plants. This paper discusses the results of two test programs. The first is a quality control inspection on 169 samples of new power generation cables. The second is a material degradation evaluation on four short cable samples removed from a coal fired plant during an equipment upgrade. The new material evaluation was performed to identify the cause of a high failure rate upon initial hi-pot testing of newly installed cables. The material degradation evaluation was performed to evaluate the need for replacement of existing cables during an equipment upgrade. Results of the evaluations have led to development of a detailed proposal for a program to evaluate cable degradation and remaining life for cables used in power generation facilities

Configuration of an inelastic flexible anchored cable

Directory of Open Access Journals (Sweden)

T. P. Dreyer

1992-07-01

Full Text Available Consider an inelastic, perfectly flexible cable with given external forces acting on the total length of the cable. The one end-point is fixed in the origin and the other end-point is anchored at a given point (a;b;c in space. The resulting configuration of the cable in space can be modelled by a system of non-linear differential equations. In this article it is shown that this continuous model of the cable can always be solved in terms of an integral. In the special case of a constant (i.e. independent of the position on the cable external force per unit length the solution is given explicitly in terms of three constants that describe the tension at the origin. These three constants are determined by the boundary values a, b and c at the other end-point, and must be calculated in general by a numerical procedure from the three resulting simultaneous non-linear equations. A few applications of this method are shown.

Triple voltage dc-to-dc converter and method

Science.gov (United States)

Su, Gui-Jia

2008-08-05

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

Development of halogen-free cables for nuclear power plants

International Nuclear Information System (INIS)

Yamamoto, Mitsuo; Ito, Kazumi; Yaji, Takeo; Yoshida, Shin; Sakurai, Takako; Matsushita, Shigetoshi.

1990-01-01

On the occasion where serious fire accidents were experienced in the past, the need for making flame-retardant wire and cable incombustible took place and has since been generalizing. Various sorts of flame-retardant cables have already been developed and been actually used. From the viewpoint of avoiding the interference with the evacuation and fire-fighting activity in case of fire or the secondary accidents such as corrosion of the distributing panel, etc., the demand for non-halogen flame-retardant cable has rapidly been increasing in recent years in some fields of general industries, because this specific cable would generate the least amount of toxic smoke or corrosive gas even when it should burn. Similar demand has been increasing also for the cable used for nuclear power plants. In this field, earnest desire has been made for the development of non-halogen flame-retardant cable having specific environmental resistance specially required at nuclear power plants in addition to the properties and capacities required in general industries. The authors have continued examinations on the anti-environmental properties of the materials for cable such as long heat resistance, radiation resistance, steam resistance and succeeded in completing various sorts of non-halogen flame-retardant cable for nuclear power plants. In this report, we will introduce various features of the cable we have developed this time as well as the long-term reliability of non-halogen flame-retardant materials. (author)

Cable Damage Detection System and Algorithms Using Time Domain Reflectometry

Energy Technology Data Exchange (ETDEWEB)

Clark, G A; Robbins, C L; Wade, K A; Souza, P R

2009-03-24

This report describes the hardware system and the set of algorithms we have developed for detecting damage in cables for the Advanced Development and Process Technologies (ADAPT) Program. This program is part of the W80 Life Extension Program (LEP). The system could be generalized for application to other systems in the future. Critical cables can undergo various types of damage (e.g. short circuits, open circuits, punctures, compression) that manifest as changes in the dielectric/impedance properties of the cables. For our specific problem, only one end of the cable is accessible, and no exemplars of actual damage are available. This work addresses the detection of dielectric/impedance anomalies in transient time domain reflectometry (TDR) measurements on the cables. The approach is to interrogate the cable using time domain reflectometry (TDR) techniques, in which a known pulse is inserted into the cable, and reflections from the cable are measured. The key operating principle is that any important cable damage will manifest itself as an electrical impedance discontinuity that can be measured in the TDR response signal. Machine learning classification algorithms are effectively eliminated from consideration, because only a small number of cables is available for testing; so a sufficient sample size is not attainable. Nonetheless, a key requirement is to achieve very high probability of detection and very low probability of false alarm. The approach is to compare TDR signals from possibly damaged cables to signals or an empirical model derived from reference cables that are known to be undamaged. This requires that the TDR signals are reasonably repeatable from test to test on the same cable, and from cable to cable. Empirical studies show that the repeatability issue is the 'long pole in the tent' for damage detection, because it is has been difficult to achieve reasonable repeatability. This one factor dominated the project. The two-step model

New, clean handling process introduced to improve cable quality

Energy Technology Data Exchange (ETDEWEB)

Hunt, C G

1990-05-01

The clean room system introduced by Canada Wire and Cable Limited in its Toronto plant for its cable manufacturing operation is described. While clean room technology is common in the food processing industry, optical and aerospace manufacturing processes, this is the first time it has been applied to wire and cable extrusion in North America. The purpose of the clean compound handling system is to prevent particle contamination in the shielding and cable insulation materials, as part of an effort to prevent premature underground electric cable failures. Two rooms are dedicated to handling different types of insulation compound, two are dedicated to receiving semi-conducting shielding material, and the fifth room functions as an air lock for the two insulation rooms. The atmosphere is highly regulated with programmable logic control. The air supply filters capture 99.97% of all particles 0.3 microns or larger. The system also maintains air temperature, relative humidity and static pressure. The life variability of cross-linked polyethylene primary distribution cable is dependant on five factors: material purity, extra clean compound handling, cable design, manufacturing process, and installation and operation practices. The clean room system is expected to result in cable that is more resistant to water treeing failures. 2 figs.

A preliminary bending fatigue spectrum for steel monostrand cables

DEFF Research Database (Denmark)

Winkler, Jan; Fischer, Gregor; Georgakis, Christos T.

2011-01-01

This paper presents the results of the experimental study on the bending fatigue resistance of high-strength steel monostrand cables. From the conducted fatigue tests in the high-stress, low-cycle region, a preliminary bending fatigue spectrum is derived for the estimation of monostrand cable...... service life expectancy. The presented preliminary bending fatigue spectrum of high-strength monostrands is currently unavailable in the published literature. The presented results provide relevant information on the bending mechanism and fatigue characteristics of monostrand steel cables in tension...... and flexure and show that localized cable bending has a pronounced influence on the fatigue resistance of cables under dynamic excitations....

Radiation techology in cable making industry

International Nuclear Information System (INIS)

Kourim, P.; Vokal, A.

1985-01-01

Electron accelerators are used in radiation cross-linking of elastomer and thermoplastic layers of cable insulation and sheathing. Another application is cross-linking of insulation bands and moulded products to achieve thermal contractibility. Ionizing radiation is used for curing insulation lacquers on winding leads. In Czechoslovakia, problems of radiation curing of silicone rubber have been studied since 1973. Instrumentation has been installed including accelerators. The feasibility has also been studied of radiation cross-linking of insulation and semiconductor cable cores of hose-type trailing cables. Polyethylene mixes have been designed and prepared which are suitable for radiation cross-linking aimed at increasing thermal resistance above 100 degC. (M.D.)

Overcurrent experiments on HTS tape and cable conductor

DEFF Research Database (Denmark)

Tønnesen, Ole; Jensen, Kim Høj; Træholt, Chresten

2001-01-01

their critical current. In this light, it is important to investigate the response of HTS tapes and cable conductors to overcurrents several times the critical current. A number of experiments have been performed on HTS tapes and cable conductors, with currents up to 20 times the critical current. During...... overcurrent experiments, the voltage, and the temperature were measured as functions of time in order to investigate the dynamic behavior of the HTS tape and cable conductor. After each experiment, damage to the superconductors was assessed by measuring the critical current. Preliminary results show...... that within seconds an HTS tape (critical current=17 A) heats above room temperature with an overcurrent larger than 140 A. Similar overcurrent experiments showed that a HTS cable conductor could sustain damage with overcurrents exceeding 10 times the critical current of the cable conductor....

Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

Science.gov (United States)

Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

2014-09-09

A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

The Selling of Cable Television 1972.

Science.gov (United States)

National Cable Television Association, Inc., Washington, DC.

The 1972 Cable Television Marketing Workshop reviewed in depth a wide variety of marketing and public relations techniques as they pertain to cable television. The workshop was attended by representatives of commercial television systems throughout the United States; it was intended to disseminate the sales and marketing experience of those…

TMI cable tracer operation and maintenance manual for assembly 417910

International Nuclear Information System (INIS)

Sumstine, R.L.

1983-11-01

This manual provides technical information and instructions to operate and maintain the cable tracer designed for the Three Mile Island (TMI) Unit 2 Reactor Building. The TMI cable tracer was developed to allow TMI personnel to trace cables in cable trays that may be tested or sectioned for destructive examination

Choice Of Computer Networking Cables And Their Effect On Data ...

African Journals Online (AJOL)

Computer networking is the order of the day in this Information and Communication Technology (ICT) age. Although a network can be through a wireless device most local connections are done using cables. There are three main computer-networking cables namely coaxial cable, unshielded twisted pair cable and the optic ...

The performance of the DC motor by the PID controlling PWM DC-DC boost converter

OpenAIRE

Can, Erol; Sayan, Hasan Hüseyin

2017-01-01

This paper presents the PID controlling direct current (DC) to the direct current boost converter feds DC motor which has a 3.68 kW and 240 V of DC voltage input on its characteristics. What is first formed is the boost converter mathematical model at the design stage. Secondly, a mathematical model of the DC motor is created so that the boost converter with the machine can be established and modeled at the Matlab Simulink. The PID controller is considered for arranging a pulse width modulati...

On and off controlled resonant dc-dc power converter

DEFF Research Database (Denmark)

2015-01-01

The present invention relates to a resonant DC-DC power converter comprising an input side circuit comprising a positive and a negative input terminal for receipt of an input voltage or current and an output side circuit comprising positive and negative output terminals for supply of a converter...... output voltage and connection to a converter load. The resonant DC-DC power converter further comprises a rectification circuit connected between an output of a resonant network and the output side circuit. The resonant network is configured for alternatingly being charged from the input voltage...... or current and discharged through the rectification circuit by a first controllable switch arrangement in accordance with a first switch control signal. A second controllable switch arrangement of the resonant DC-DC power converter is configured to select a first impedance characteristic of the resonant...

The Topologies Research of a Soft Switching Bidirectional DC/DC Converter

DEFF Research Database (Denmark)

Zhang, Qi; Zhang, Yongping; Sun, Xiangdong

2017-01-01

A soft-switching solution implemented to the traditional bidirectional DC/DC converter is developed. The soft-switching cell, which composed of three auxiliary switches, one resonant capacitor and one resonant inductor, is equipped in the traditional bidirectional DC/DC converter to realize circuit...... circle. And the proposed topology of bidirectional soft-switching dc-dc converter(TASBC) performs ideal soft switching at boost operations. The characteristics of the proposed converter has been verified by MATLAB simulations and experimental results....

Subsea Cable Tracking by Autonomous Underwater Vehicle with Magnetic Sensing Guidance.

Science.gov (United States)

Xiang, Xianbo; Yu, Caoyang; Niu, Zemin; Zhang, Qin

2016-08-20

The changes of the seabed environment caused by a natural disaster or human activities dramatically affect the life span of the subsea buried cable. It is essential to track the cable route in order to inspect the condition of the buried cable and protect its surviving seabed environment. The magnetic sensor is instrumental in guiding the remotely-operated vehicle (ROV) to track and inspect the buried cable underseas. In this paper, a novel framework integrating the underwater cable localization method with the magnetic guidance and control algorithm is proposed, in order to enable the automatic cable tracking by a three-degrees-of-freedom (3-DOF) under-actuated autonomous underwater vehicle (AUV) without human beings in the loop. The work relies on the passive magnetic sensing method to localize the subsea cable by using two tri-axial magnetometers, and a new analytic formulation is presented to compute the heading deviation, horizontal offset and buried depth of the cable. With the magnetic localization, the cable tracking and inspection mission is elaborately constructed as a straight-line path following control problem in the horizontal plane. A dedicated magnetic line-of-sight (LOS) guidance is built based on the relative geometric relationship between the vehicle and the cable, and the feedback linearizing technique is adopted to design a simplified cable tracking controller considering the side-slip effects, such that the under-actuated vehicle is able to move towards the subsea cable and then inspect its buried environment, which further guides the environmental protection of the cable by setting prohibited fishing/anchoring zones and increasing the buried depth. Finally, numerical simulation results show the effectiveness of the proposed magnetic guidance and control algorithm on the envisioned subsea cable tracking and the potential protection of the seabed environment along the cable route.

75 FR 27401 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-30, DC-9-40, and DC-9-50...

Science.gov (United States)

2010-05-17

... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 9-30, DC-9-40, and DC-9-50 Series Airplanes... airworthiness directive (AD) for certain Model DC-9-30, DC-9-40, and DC-9-50 series airplanes. This AD requires... this AD to detect and correct the potential for an arc/spark condition to occur within the fuel boost...

High voltage transmission of electrical energy over long distances

Energy Technology Data Exchange (ETDEWEB)

Tewari, S W

1962-07-01

Technical aspects of ac transmission lines, additional means of improving stability ac transmisson lines, insulation problems, ac transmission by cables, high voltage dc transmission, advantages of dc over ac transmission, disadvantages of dc transmission, use of underground cables for dc transmission, history of the development of conversion equipment; transmission schemes adopted on Gotland Island, Sweden; and economics of ac and dc transmission are discussed.

Wind-Tunnel Investigation of the Aerodynamic Performance of Surface-Modification Cables

Directory of Open Access Journals (Sweden)

Hiroshi Katsuchi

2017-12-01

Full Text Available The wind-induced vibration of stay cables of cable-stayed bridges, which includes rain-wind-induced vibration (RWIV and dry galloping (DG, has been studied for a considerable amount of time. In general, mechanical dampers or surface modification are applied to suppress the vibration. In particular, several types of surface-modification cable, including indentation, longitudinally parallel protuberance, helical fillet, and U-shaped grooving, have been developed. Recently, a new type of aerodynamically stable cable with spiral protuberances was developed. It was confirmed that the cable has a low drag force coefficient, like an indented cable, and that it prevented the formation of water rivulets on the cable surface. In this study, the stability for RWIV of this cable was investigated with various flow angles and protuberance dimensions in a wind-tunnel test. It was found that the spiral protuberance cable is aerodynamically stable against both RWIV and DG for all test wind angles. The effects of the protuberance dimensions were also clarified. Keywords: Rain-wind-induced vibration, Dry galloping, Stay cable, Wind-tunnel test

A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid

Directory of Open Access Journals (Sweden)

Haojie Wang

2016-07-01

Full Text Available It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC is proposed for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control.

A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid

DEFF Research Database (Denmark)

Wang, Haojie; Han, Minxiao; Yan, Wenli

2016-01-01

It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC) is proposed...... for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load...... changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control....

NEPO cable system aging management programs

International Nuclear Information System (INIS)

Toman, G.

2002-01-01

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

Computer-Aided Engineering Of Cabling

Science.gov (United States)

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

Assessment of sodium conductor distribution cable

Energy Technology Data Exchange (ETDEWEB)

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)

On Dynamic Analysis, Optimal Distribution of Cable Tention and Experiment of Cable NET Structures in Large Radio Telescope

International Nuclear Information System (INIS)

Duan, Baoyan

2002-01-01

This paper presents the researching activities, in which the nonlinear dynamic analysis, optimization of the cables' tension distribution, real 50 meters model experiment are discussed. The long cable structure has been utilized in new generation large radio telescope with the diameter of 500 meters. In design, there are six high concrete towers form which are six computer controlled long cables about 250 meters long met at a cabin, which is a hemisphere with 6 meters diameter. The cabin can be moved three dimensional to track the target. Within the cabin, there is a stable platform. The positioning precision for the platform and cabin are 4mm and 50cm respectively. By which means, the poisoning accuracy can be received becomes a sensible and important problem. For the sake of this, study on vibration of cable with respect to random wind, such as nonlinear response, vortex and galloping, is investigated in this paper. Desirable design is that the tension forces among the six long cables are the same, at least as even as possible. This will be benefit to the control of the system, so that the higher dynamic positioning precision is easy to be obtained. To meet this kind of requirement, the optimal distribution of the cable tensions among cables is discussed and pretty good result is received. Before the real 500 meters diameters antenna is built, an experiment model with 50 meters diameter was built in Xidian University of China, shown in figure 2. The dynamic analysis on vibration (random wind response, vortex and galloping), optimization of the cable tensions' distribution is made with good result. Lots of 50-meter-model site experiments are carried out with useful and valuable results, form which the theory and simulation model has been improved repeatedly until both the model simulation and experiment results are very closed so that the difference can be accepted from the viewpoint of thoroughly, systematically and deeply in the paper. The conclusion

Broadband Wireline Provider Service: Cable Modem - Other; BBRI_cableOther12

Data.gov (United States)

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...

Using PBL to Improve Educational Outcomes and Student Satisfaction in the Teaching of DC/DC and DC/AC Converters

Science.gov (United States)

Martinez-Rodrigo, Fernando; Herrero-De Lucas, Luis Carlos; de Pablo, Santiago; Rey-Boue, Alexis B.

2017-01-01

This paper examines the question of how to use project-based learning to increase student performance and satisfaction in a power electronics course addressing the topics of dc/dc and dc/ac converters, the assembly of a dc/dc converter, and the use of a commercial speed drive. A detailed presentation of the methodology is shown, and the results…

Optimized and practical electrical joints for CORC type HTS cables