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A new methodology for designing large-scale single-flux-quantum (SFQ) circuits using passive-transmission-line (PTL) consisting of about 20,000 logic cells which approximates to more than 400,000 Josephson junctions including splitters to distribute the clock signal is presented.

A study of the new generation of high-temperature superconductor (HTS) power equipment, such as power cables, synchronous condensers, fault current limiters and transformers for the electric power grid is presented. The first HTS power equipment addresses the growing need for dynamic reactive power compensation for grid stability and power quality.

An experiment to determine the significant parameters of a 3-GW 200-kV dc superconducting cable system, which influence the transient voltage distribution in the various parts of the cable, is presented. More research is necessary to determine the optimal value of the grounding impedance and the distance between grounding points.

Transient voltage distribution in a dc superconducting cable, consisting of four concentric metallic cylinders is analyzed. Transient voltages would appear across the RETURN cryogen flow and also across the vacuum space in the cryogenic enclosure and the two systems might suffer permanent damage caused by unwanted electrical transients.

Efficient line-based architectures for two-dimensional discrete wavelet transform (2-D DWT) are presented in this paper. We first present a four-input/four-output architecture for direct 2-D DWT that l-level decomposition of a N x N image could be performed in approximately [N.sup.2] / 4 intra-working clock cycles (ccs), where the parallelism among four subbands transforms in lifting-based 2-D DWT is explored. By using this four-input/four-output architecture, we propose a novel pipelined architecture for multilevel 2-D DWT that can perform a complete dyadic decomposition of N x N image in approximately [N.sup.2] / 4 ccs. Performance analysis and comparison results demonstrate that, the proposed architectures have faster throughput rate and good performance in terms of production of throughput rate and hardware cost, as well as hardware utilization. The proposed pipelined architecture could be an efficient alternative for high-speed and/or low-power applications. Index Terms--Discrete wavelet transform (DWT), highspeed/lower power, lifting scheme, pipelined.

The possibility of working of electric power transmissions by DC superconducting cables of power ratings 3 GW and 500 MW is studied, taking into consideration two designs, one surrounded by high voltage high temperature superconductor cylinder and the other design return and supply streams of cryogen lie on the grounded side of the system. The electric power transmission by DC superconducting cables could be operated successfully.

The fabrication of a single flux quantum (SFQ) circuit component, SFQ-dc converter and a confluence buffer is detailed making use of YBa(sub 2)Cu(sub 3)O(sub 7--delta) ramp-edge junction technology at high temperature. The smaller I(sub c) values are responsible for narrowest margins of the dc supply currents in the temperature range of 42 to 61 K and the simulation results showed consistency.

A code for the geometric description of generic multistrand multistage cables and for the calculation of the strand self- and mutual inductance coefficients is developed. Results build a database that can be used to validate several numerical coupling parameters in super-conducting cables.

A method of designing single-flux-quantum (SFQ) logic circuits with passive gate-to-gate interconnections is developed. Based on this method, a 2 x 2 switch is designed in which all the interconnections are implemented with passive transmission lines while short Josephson transmission line segments are used only to adjust the signal timings.

The effect of kinetic inductance on the index of refraction and frequency response of a superconductive-based left-handed transmission line (SLHTL) are studied. The possible applications of the tunable SLHTL in the design of miniaturized tunable resonators and filters are discussed.

Nonlinear circuit models were developed for multiple coupled superconducting transmission lines. The aim of these models was to predict and design high-performance High Temperature Superconductor (HTS) resonators with high quality factor (Q(sub 0)) and reduced intermodulation products (IMD).

A study was conducted to investigate the parasitic electromagnetic coupling interactions within some typical Low-Temperature Superconductive (LTS) microstrip geometries. The result proves that in the case of modern microstrip lateral dimensions and nominally biased Josephson junctions, these parasitic interactions do not disturb the functionality and the fabrication yield of the Rapid Single Flux Quantum (RSFQ) circuits terminating the influenced microstrip.

A demonstration of the single-flux-quantum (SFQ) microprocessors using passive transmission lines (PTLs) is presented. It is found that the reduction of the delay in the long interconnection by using PTLs is highly effective in designing the SFQ microprocessor and the introduction of PTLs gave the flexibility for designing the floor plan, and improved the performance of the microprocessor by 20% compared with the previous design.

The timing jitter in a Josephson transmission line (JTL) that induces timing errors at logic gates is studied. The study experimentally determines the timing parameters in several logic cells, which indicated that the deviations between actual and nominal values are within 2 ps.

Passive transmission lines (PTLs) were used to design and fabricate a 4 x 4 switch in which all interconnections were implemented. The result showed that the PTL-version 4 x 4 switch had 50% fewer junctions and required 55% less powering current.

Two types of long nitrogen cooling channels are developed to study the hydraulic characteristics of superconducting cables. The basic data of initial cooling, temperature distribution along the channels and oscillating conditions are investigated.

The effect of ground planes of the current-induced critical states and flux penetration for a thin superconducting strip carrying a microwave current was calculated numerically. The nonlinear response represented by the dependence of the surface resistance and reactance were also calculated and it was found that for a separation d/a-0.2, the presence of the ground planes leads to strong effects on the penetration law of the critical state model.

Research describing the behavior of high temperature superconducting power cables when subjected to a short circuit is presented. Simulated tests are analysed with respect to degradation of the cable and cryogenic coolant response.

Research describing the operational limits for long length high temperature superconducting power cables is presented. In particular ac loss, thermal loss and cooling configuration are investigated.

Research describing losses in high temperature superconducting cables is presented. The results of a calorimetric measurement technique based on temperature differences in flowing liquid nitrogen are analysed.

Research describing the behavior of high temperature superconducting tapes subjected to overcurrents is presented. The effects of short circuits on cable conductors is examined by successive critical current measurements.

A sinusoidal wave solution was derived for an asymmetric field high temperature superconducting transmission line in the presence of vortices. This was done by using the electrodynamic field equations for a type-II superconductor in the mixed state. The dependence of the slow mode propagation on the temperatures, frequency and static magnetic field were numerically demonstrated by the solution. This resulted in the elucidation of the effects of vortices on propagation characteristics in a superconducting strip line.

The [LN.sub.2] cooling system for fully flexible three phase high Tc superconducting cables was addressed in this paper. Explicit formulas were presented to calculate the cooling capacity and stability. Thereafter, the stress cracking and the thermal contraction of electrical insulation at low temperature were analyzed theoretically and experimentally. The thermal contractions of the ultra-high molecular weight polyethylene insulation layer of short model cables were measured with the moire method and strain gauge method. The measured result was in good agreement with the theoretical result. Both the theoretical and experimental results confirmed that the insulation does not suffer from the stress cracking problem on cooldown, and it is an excellent candidate for the electrical insulation at low temperature. Keywords: high Tc superconducting cable, cooling system, cooling characteristic, UHMW-PE, dielectric, stress analysis, thermal contraction.

The response of a Josephson transmission line (JTL) to a picosecond input pulse has been studied with a low-temperature electro-optic sampling system with subpicosecond resolution. Niobium metal-semiconductor-metal photodiodes were connected to 3, 4, 19 and 20-stage JTLs. The JTL bias and input pulse amplitude were then varied to observe fluxon interaction and time delay of the JTL stages. Results indicate that dipolar oscillations due to the coupling of the junction capacitance and line inductance dominate the behavior of the JTL.

Results of AC loss measurements for five of the nine 1-meter long, high-temperature superconducting transmission cable prototypes built by Southwire Co and Oak Ridge National Laboratory. The losses were determined by a calorimetric and an electrical technique. There is good agreement between the two sets of AC loss data and with results from Dresner's theory. The AC loss data also agree with the theoretical hysteresis loss based on only the outer two layers carrying the total current at low currents of incomplete penetration.

The impact of the mechanical properties of high-temperature superconducting (HTS) power cables on its critical current (Ic)has been studied. A thermal cycle test, a bending test and a tensile test were conducted on the HTS cable cores. Results indicate that heat does not affect Ic while the bending radius does. The radius must be greater than 1 meter for the Ic not to be significantly degraded. Tensile strains of 0.2% does not reduce the Ic but HTS tapes inside the cable can slide in liquid.

The performance of a pair of 1500 A high-temperature superconducting (HTS) current leads during transient warm-up following a loss of intercept cooling has been examined by using the ANSYS finite element software. Results indicate that the HTS lead is thermally decoupled from the rest of the lead when the heat generated by the HTS superconductor exceeds convective cooling by a factor of 10. Experimental data reveal that it is possible to protect the HTS leads through the addition of sufficient helium mass flow.

A description of the high-temperature superconducting 110 kV/400 MVA power cable for future power transmission systems being developed at Siemens is presented. It is made of 2223 BPSCCO multifilamentary tapes, an LN2 high-voltage insulation, a flexible cryostat, terminations and an LN2 cooling system. The dielectric loss of the cable is negligible while the full-load thermal loss and superconductor loss are similar. The shield loss is lower than the conductor loss since the cable has a lower magnetic field.

The single and three-phase ac losses for two prototype multistrand conductors (PMCs) manufactured from (Bi,Pb)2Sr2Ca2Cu3Ox (Bi-2223) silver-sheathed tape as a function of temperature and current were measured. The conductors differed significantly in the critical current I(sub C) of the individual tapes that make up the PMCs. A comparison of the single-phase experimental data with a model based on the critical state model showed good agreement.

Research was conducted to examine the electrical aspects of the choice of former in a high T(sub C) superconducting power cable. The objective was to analyze the magnitude and the relevance of unbalanced axial magnetic field as a source of electrical loss. Results indicate that only materials with low resistivity may under certain conditions significantly contribute to the total AC-losses in a superconducting cable.

A 1kWh/1MW module-type semiconducting magnet energy storage (SMES) called Experimental SMES of Kyushu Electric Power Company Inc has been developed. The main points of its design are the converter-coil module system, modified-D shaped coil with mechanical support, newly developed high temperature superconducting current leads, total system operation and liquid helium-vessel type cooling. Results of preliminary test indicate the expected control function of the SMES system in the extent of its capacity.

The development of a successful approach to produce electric power superconducting applications at TRINITI is described. Pilot superconducting magnet systems with large aperture for pulsed 10 MW MHD generators were constructed and tested. The opportunities of the magnet systems applications for other purposes such as high-gradient magnetic purification of liquids with paramagnetic impurities; clinical and biological research; and an additional magnetic field for electromagnetic accelerators were also studied

Research was conducted to examine the concept of the quench detection system for the long superconducting bus lines. The detection system uses a cancellation method of the voltages of the positive and the negative bus line conductors each other. The Fuzzy theorem was used to incorporate not only the voltage signals but also other signals such as the liquid He inlet pressure, the liquid He flow rate and the currents. Results illustrate the validity of the system in usual operation.

Alternating current (ac) losses for a stack of Bi2223/Ag were found to be a function of the angular difference between the tape face and the applied ac magnetic field. The results were compared against the values derived by using the Bean critical-state model. The subsequent analysis revealed that, despite the seeming agreement of the Bean model with the general qualitative behavior of the calculated loss, the model failed substantially in its predictions.

The design and assembly of a versatile, high-temperature superconducting (HTS) cable test facility were conducted at Oak Ridge National Laboratory. The objective was to analyze the performance of prototype HTS power transmission cables at lengths in the range of 1 to 5+ m. Dedicated sensors scanned by 10-channel multimeters connected via cable and fiber optic to a personal-computer-based data acquisition system were used to generate the electrical and cryogenic data.

The design of the CERN facility called FRESCA for Faciity for the REception of Superconducting CAbles is described. Its features include independently cooled background magnet, temperature ranging rom 1.8 and 4.5 K, long measurement length of 60 cm, test currents up to 32 kA, c, measurement of the curent distribution between the strands and field perpendicular or parallel to the cable face.

The first measurements of superconducting cables performed at the National High Magnetic Field Laboratory are presented. The experiments were conducted on cables designed for and used in the inner coils of the world record dipole magnet D20. Results show that two cables that were made with Intermagnetics General Corp strand and the other with Teledyne Wah Chang strand have very different I(sub c) versus pressure behavior. The different internal structure of the two strands indicate that the high porosity of internal tin strand is detrimental.

A textured yttria-stabilized zirconia layer was used to coat in a continuous process one meter long tapes based on 50-100 microns thick by 1 cm wide nickel alloy substrates by means of ion beam-assisted deposition. This was followed by a 1.2 microns thick layer of YBCO by pulsed layer deposition. A tape with a critical current (I(sub c)) at 75K of 96 A over an 87 cm measurement length was the best result obtained to date. The results showed that the highest and lowest I(sub c) values fell within a range of 25%.

A new large bore 10 T @4.5 K Nb3Sn model is under the development stage in the Netherlands following the successful operation of the 11 T Nb3Sn experimental dipole magnet MSUT. An innovative 'powder in tube' type of Nb3Sn conductor with an increased number of filaments was developed by ShapeMetal Innovation for application in the system. The diameter of the filaments was reduced to about 20 microns after reacting for only 33 hours at 675 degrees C. The strand diameter used was 0.9 mm.

The critical current density of two modified jelly roll wires was measured as a function of magnetic field and of strain at 4.2 K. The two wires were the Hot Isostatic Pressed (HIP'ed) and unHIP'ed Nb3Sn modified jelly roll wires. Both wires were investigated for the reversibility of critical current density. For the HIP'ed sample, the critical current and upper critical field were decreased. Compared to the unHIP'ed wire, the reduced upper critical field of the HIP'ed wire was found to be less sensitive.

Research was conducted to examine the technical and economical benefits of superconducting fault current limiters (SFCL) in power systems. The placed in the network that were studied include the feeder locations of power stations, of power station auxiliaries and of local generating units. Results indicate that feeder locations of power stations and wind generators are the most economical places for SFCL.

An EMTP model of a resistance-tupe and a rectifier-type for superconducting fault current limiter (SFCL) was developed. The SFCL parameters, which a user specifies when he plans to introduce an SFCL into a power system, were defined. The setting method of the specific parameters of a resistance type and a rectifier type SFCL installed in overhead transmission lines are proposed so that they may not affect the correct operation of protective relays.