Cable Applications Research Articles

Installation and operation of the Southwire 30-meter high-temperature superconducting power cable

Southwire Company has installed, tested and is operating the first real-world application of a high-temperature superconducting cable system at its headquarters in Carrollton, GA, USA. The cable is powering three Southwire manufacturing plants, marking the first time a company has successfully made the difficult transition front laboratory to practical field application of an HTS cable. The cables are rated at 12.4-kV, 1250-A, 60 Hz and are cooled with pressurized liquid nitrogen at temperatures from 70-80 K. Before placing the cables into service, extensive offline electrical testing was performed including voltage withstand, measurement of DC critical current, extended load current testing, rated voltage testing and partial discharge measurement. The cables were energized on Jan. 5, 2000 for online testing and operation, and by the end of August 2000, had provided 100% of the customer load for 2164 hours.

Field demonstration of a 24-kV warm dielectric HTS cable

Prototype HTS cable systems have been installed in laboratories and tested successfully around the world, proving the technical feasibility of the HTS cable system. Commercial cable systems, however, must not only be feasible, but meet practical requirements as well. To facilitate the transition of HTS cable technology from the laboratory to the field, a project has been initiated to install the world's first HTS power cable to deliver electricity in a utility network. This program will demonstrate a retrofit upgrade application of the warm dielectric HTS cable design in the Detroit Edison utility network, and involve the design, engineering, installation, test and routine operation of a 24-kV, 100 MVA, 3-phase cable system. Each HTS cable will carry 2400 A RMS, a level triples the ampacity of original cables powering this circuit. This paper addresses the field application of HTS cables in the context of the demonstration program. Customer perception will play a crucial role in the adoption of HTS cable systems by the utility industry. An updated perspective provided by the utility industry team members is included.

Practical AC loss and thermal considerations for HTS power transmission cable systems

The use of high-temperature superconducting materials for power-transmission cable applications is being realized in prototype situations. It is well known that AC loss decreases as the temperature of the conductor decreases. Also, thermal losses are higher at lower temperatures, owing to the increased temperature difference between ambient and cryogenic operating conditions. Both counterflow and parallel-flow cooling arrangements have been proposed in the literature and significantly affect temperature distribution along the cable. In this investigation, the counteracting AC loss and thermal losses are analyzed for both cooling configurations to determine the benefits and limits of each. The thermal-insulation performance levels of materials versus those of typical systems in operation are presented. Widespread application of long-length flexible cable systems, from the refrigeration point of view, will depend on an energy-efficient cryogenic system that is economical to manufacture and operate. While the counterflow arrangement will typically have a lower heat load, it has a length limit arising from the large pressure drop associated with the configuration.

The Application of Large Tonnage Pressure Dispersion Anchor Cable in Slope Engineering

The Application of Large Tonnage Pressure Dispersion Anchor Cable in Slope Engineering

Potential Electric Power Applications for Magnesium Diboride

ABSTRACTThe newly discovered superconductor, MgB2, has significant potential for a number of electric power applications, even though its critical temperature, TC, is “only” 39 K. In recent months, there has been rapid improvement in its critical state parameters, JC and H*, properties crucial to deployment in power devices, which now rival NbTi at 4.2 K, and equal or surpass many of the high temperature superconducting copper oxide perovskites in the 20 – 25 K range. Moreover, substantial progress has been achieved in realizing wire embodiments that appear economically scalable to commercial production. In this paper, we will review several opportunities to exploit these developments for transformer and electric cable applications, and hint at the possibility of a novel and visionary power delivery system centered on an MgB2-based dc cable cooled by gaseous or liquid hydrogen supplying both electrical and chemical energy to the end user.

Comparison of the burning behaviour of electric cables with intumescent coating in different test methods / Vergleich des Brandverhaltens elektrischer Kabel mit dämmschichtbildenden Anstrichen unter verschiedenen Testmethoden

Cables used for electric power and control systems represent a significant potential hazard, particularly in buildings with highly complex wiring. To reduce the risk of ignition and of flame spread and to limit the fire effects, protective intumescent coatings or cables with fire retardant insulation materials have been implemented in safety related areas and locations, particularly of nuclear power plants. Since 1994, extensive experimental research has been performed by iBMB of the Braunschweig University of Technology on the bunting behaviour of unprotected as well as coated PVC cables. The main goal of this investigations was to develop a qualification method and licensing procedure for cable systems with protective coatings based on realistic fire conditions, which is accepted by the building authorities for application in buildings in general and, in particular, in nuclear power plants. For comparative results of tests with intumescent coatings in different scales - according to the standard IEC 332-3 (large scale), German standard DIN 4102-1 (intermediate scale) and ISO 5660 (small scale) - will be introduced. The setup of the different test procedures and the corresponding phases of natural fires will be discussed. It will be shown that cables with protective coatings are appropriate for fire scenarios up to a developed room fire while only resistance to a local ignition source could be guaranteed by testing according to international or national valid standard. The necessity of testing cables with insulation material, which should guarantee a fire retardant behaviour, by these different methods should be reasonable, because depending on the results of future tests, a more distinguished qualification and application of cables might be possible.

The Application of OVM Extracorporeal Cable in Tanigawa Bridge, Hanoi, Japan

The Application of OVM Extracorporeal Cable in Tanigawa Bridge, Hanoi, Japan

Linear optical modulation in a serially cascaded electroabsorption modulator

ABSTRACT: An all-optical linearization scheme in a serially cascadedEAM using different deri ati e signs of the transfer function of an EAMis proposed. Both the IMD3 and IMD5 supressions are obtained at thesame dc bias oltage, and 15 dB of SFDR enhancement is achie ed innarrowband operation. 2000 John Wiley & Sons, Inc. MicrowaveOpt Technol Lett 27: 447 450, 2000. Key words: electroabsorption modulator; linearity; intermodulationproducts; SFDR; analog optical link I. INTRODUCTION The optical transmission of analog radio-frequency RF sig-Ž.nals has wide applications, including wireless communicationssystems, cable television applications, and antenna remoting.External optical modulation becomes important for the low-loss transmission of a millimeter-wave band and RF signalover a fiber link due to its high-frequency response andlow-chirp characteristic. For external modulation, a Ti-dif-fused LiNbO Mach 3 Zehnder interferometer modulatorŽ. Ž .MZM and an electroabsorption modulator EAM aremainly used for digital optical transmission. An EAM takesadvantage of the low driving voltage, small size, monolithicintegration capability with other optical components, andbroad bandwidth compared to an MZM. But an EAM has acomplicated nonlinear transfer function. So an intermodula-tion distortion IMD product and a harmonic distortionŽ.product in subcarrier multiplexing SCM transmission ofŽ.analog radio-frequency signals are generated, and the analogoptical link performance is degraded. Thus, nonlinear prod-

Cable technology and applications in the 21st century

The paper briefly discusses the developments and technology in underground cables. XLPE cables, fluid filled cables and installation methods are outlined. The use of intelligent cables should become commonplace, with information on temperature, mechanical, and electrical integrity being transmitted to intelligent transducers via optical fibers incorporated into the cable construction.

A 3 V 10 b 100 MS/s digital-to-analog converter for cable modem applications

This paper describes a 10 b 100 MS/s CMOS digital-to-analog converter (DAC) for cable modem applications. Differential switches with the proposed deglitching circuit and the cascode current sources, separated from the unit decoded current cell matrix improve the dynamic performance. The proposed and conventional prototype DACs are fabricated in a 0.35-/spl mu/m CMOS process. The measured differential and integral nonlinearities of the proposed DAC shows /spl plusmn/0.17 LSB and /spl plusmn/0.43 LSB at a 10 b level, respectively. At 100 MS/s, the spurious-free dynamic range is 66 dB for a 100 kHz input signal and 52 dB for a 10 MHz input signal.

Design of superconducting power cables

Superconducting power cables are one of the most promising energy applications of high-temperature superconductors. Losses in superconducting power cables are mainly due to AC, thermal and dielectric effects. The interplay of cable geometry, operating conditions, transmitted power, and the resulting losses are considered. The design studies indicate that for Bi-2223 cables with warm dielectric an operating temperature well below 77 K is favoured. For operating temperatures of 45–50 K low-cost Bi-2212 superconductors could be an alternative to Bi-2223. The superconductor properties required for the cable application are briefly discussed. Finally, a design concept for a loss-optimised superconducting 112.5 MW single-phase transmission cable is presented.

Numerical Analysis of Nonlinear Wave Propagation in Elastic Submerged Cables

This paper analyzes the coupled nonlinear tangential-normal waves that propagate along underwater cable suspensions. Taken with the recently developed linear theory governing the in-plane structural waves (Behbahani-Nejad and Perkins, 1996) and an analysis of nonlinear out-of-plane waves for submerged cables (Behbahani-Nejad and Perkins, 1997), this investigation contributes further understanding toward a nonlinear three-dimensional theory for wave propagation along fluid-loaded cables. The nonlinearities present in the in-plane model render the cable/fluid model intractable by exact analytical methods. A numerical solution is pursued in this study using finite difference algorithms. To this end, an infinite cable domain is divided to two subdomains, namely an interior (finite computational) domain and exterior (infinite far-field) domain. Closed-form solutions for the approximate linear theory are employed for the far field in constructing nonreflecting boundary conditions for the computational domain. Numerical results highlight the governing role of nonlinear hydrodynamic drag for underwater cable suspensions. The numerical results further demonstrate that most analyses of cables in air are not useful for underwater cable applications.

Application of OVM Parallel Steel Strand Cable in QueShi Bridge Project

Application of OVM Parallel Steel Strand Cable in QueShi Bridge Project

Application of pressure type anchor cables and load dispersed anchor cables in reinforcement engineering

Application of pressure type anchor cables and load dispersed anchor cables in reinforcement engineering

A CMOS dual-channel, 100-MHz to 1.1-GHz transmitter for cable applications

A dual-channel wide-band transmitter for cable applications is presented that has more than a decade frequency coverage. The chip consists of two parallel transmitters that are both fully operational from 100 MHz up to 1.1 GHz. Using a single-ended current-mode output topology, the radio-frequency (RF) output signals are lossless combined by summing the output currents. The third-order harmonic of the oscillator signal is filtered by a wide-band polyphase filter. The complex filtering operation is mathematically described in this paper. The on-chip integrated oscillators have a measured 55-1200 MHz tuning range. Using the polyphase filter, a linear mixer topology, and a linear output driver, all distortion components are below -40 dBc. All intermodulation products of the two channels are smaller than -48 dBc. In this way, it is guaranteed that the parallel channels do not disturb the other channels in the frequency band even without any channel-specific filtering. Each channel delivers the designed -16-dBm RF output signal. The measured transmitter noise floor is situated at -139.8 dBc/Hz. The chip has been processed in a standard 0.5 /spl mu/m CMOS technology.

Stabilization of peroxide crosslinked polyethylene

In peroxide crosslinked low density polyethylene for wire and cable applications there is a critical balance between the additives. Normally dicumyl peroxide is applied as the crosslinking agent and stabilizers are needed towards thermo-oxidative degradation as described by existing specifications. In addition, the phenomenon known as premature crosslinking, referred to as “scorch”, demands that a certain amount of a phenolic stabilizer deactivates radicals formed during the extrusion step. The aim of this study was to correlate the structure of different phenolic compounds to their capability to react with radicals formed during the extrusion, which would give information in design of new compounds for which scorch properties are of importance. This work shows that the less hindered the phenol is, the more it can contribute to the improvement of the scorch behavior. On the other hand, a good stabilizing effect can only be achieved with hindered phenols together with a secondary stabilizer. Since there is a limit to the absolute amount of additives in LDPE also the molar weight of the additives as well as the number of active groups are crucial for the overall performance of the cable compound. The balance between the different additives to achieve a technically reliable solution is discussed.

Stabilization of peroxide crosslinked polyethylene

In peroxide crosslinked low density polyethylene for wire and cable applications there is a critical balance between the additives. Normally dicumyl peroxide is applied as the crosslinking agent and stabilizers are needed towards thermo-oxidative degradation as described by existing specifications. In addition, the phenomenon known as premature crosslinking, referred to as scorch, demands that a certain amount of a phenolic stabilizer deactivates radicals formed during the extrusion step. The aim of this study was to correlate the structure of different phenolic compounds to their capability to react with radicals formed during the extrusion, which would give information in design of new compounds for which scorch properties are of importance. This work shows that the less hindered the phenol is, the more it can contribute to the improvement of the scorch behavior. On the other hand, a good stabilizing effect can only be achieved with hindered phenols together with a secondary stabilizer. Since there is a limit to the absolute amount of additives in LDPE also the molar weight of the additives as well as the number of active groups are crucial for the overall performance of the cable compound. The balance between the different additives to achieve a technically reliable solution is discussed.

Advances in metallocene polymers for wire and cable applications

When combined with manufacturing and process control capabilities, these metallocene catalysts have created new polymers that are being used in a variety of applications, including wire and cable insulation and jacketing.

Application of OVM200 cable in Jinwu Bridge

Application of OVM200 cable in Jinwu Bridge

Application of external preconditioning cable in structural strengthening engineering

Application of external preconditioning cable in structural strengthening engineering