Yuuichi Ashibe

Phase II of the Albany HTS Cable Project

High-temperature superconducting (HTS) cable systems are expected to be a solution for improvement of the power grid and three demonstration projects in the real grid are underway in the United States. One of these is the Albany, NY HTS Cable Project, involving the installation and operation of a 350 meter HTS cable system with a capacity of 34.5 kV, 800 A, installed between two substations in National Grids electric utility system. A 320 meter and a 30 meter cable are installed in an underground conduit and connected together by a joint, or splice in a vault. In Phase I of this project, the cables were fabricated with DI-BSCCO wire in a 3-core-in-one cryostat structure. After the installation of the HTS cable system, the in-grid operation began on July 20, 2006 and operated successfully in unattended condition through May 1, 2007. In Phase II, the 30 meter section was replaced by a 2G (YBCO) cable. The 2G cable was fabricated with SuperPowers YBCO coated conductors in a 3-core-in-one cryostat. After replacement of the 30 meter section, the joint and one termination were reassembled and the commissioning tests that included initial cooling, critical current measurement and DC withstand voltage test were completed successfully. After the commissioning tests, the HTS cable system with a 30 meter YBCO cable and a 320 meter DI-BSCCO cable was re-energized on January 8, 2008 and started again to operate in a live utility network. This paper describes the latest status of the Albany HTS cable project.

Fabrication and Installation Results for Albany HTS Cable

The Albany project has installed a high temperature superconducting (HTS) cable with a 350 m length in 34.5 kV and 800 Arms in the real power grid of the National Grid Power Company. The type of the cable is a 3 cores in a cryostat. Bi-2223 wires manufactured with SEI new sintering method, CT-OP, is used as both superconducting conductor and shield. The Cable was manufactured and shipped to the Albany test site after passing various tests such as Ic measurement, voltage tests, pressurized tests, and so on. Cable installations into a 320 m long conduits and a 30 m long conduit under ground was completed successfully. The cable was pulled with 2.5 ton tension, which is within its allowable limit. A joint between the 320 m cable and the 30 m cable was assembled in an underground vault. Cable terminations were also assembled at both ends of the cable. After all of the installation, the initial cooling was conducted successfully and then in-grid operation was started on July 20th in 2006 after confirmation of cable performance.

Verification tests of a 66 kv HTSC cable system for practical use (first cooling tests)

Abstract Tokyo Electric Power Company and Sumitomo Electric Industries, Ltd. have been jointly developing elementary technologies for an high temperature superconducting (HTSC) cable system, such as conductor wound with HTSC wires, thermal insulation pipes, terminations and so on. Verification tests of a 100 m HTSC cable system integrating these elementary technologies have been conducted in collaboration with Central Research Institute of Electric Power Industry (CRIEPI) to verify its long term electric and cryogenic properties. The cable conductor is composed of four layers of Bi-2223 wires wound spirally around a former. Polypropylene laminated paper impregnated with liquid nitrogen is adopted as cable insulation for its properties of high insulation strength and low dielectric loss. HTSC wires are also wound around the electrical insulation to form an electrical and magnetic shield. To reduce heat invasion from ambient temperature part, multi-layer insulation is wound between the co-axial stainless corrugated pipes where high vacuum is maintained. The cable was partially installed into a ∅ 150 mm duct and formed in a U-shape. Each end has a splitter box and three terminations. The cable and the terminations are cooled using two separate sets of a pressurized and sub-cooled liquid nitrogen cooling system. The cable has been developed and laid at CRIEPIs test site and long-term tests have been under way since June, 2001. This paper presents the design of the cable and some results of the first cooling tests.

Test Results of a 30 m HTS Cable for Yokohama Project

HTS cable demonstration project supported by Ministry of Economy, Trade and Industry (METI) and New Energy and Industrial Technology Development Organization (NEDO) has started in Japan. The target of this project is to operate a 66 kV, 200 MVA HTS cable in the live network of Tokyo Electric Power Company in order to demonstrate its reliability and stable operation. The design of the HTS cable with DI-BSCCO has been completed as well as those of a termination and a joint. A 30-meter HTS cable system with terminations, a joint and a cooling system was installed in SEI facility to confirm their design and performance. Various tests as voltage tests, nominal and over current tests, heat cycle tests, heat loss measurements and so on were conducted and it is verified that the cable has good performances as design. This paper describes the design and test results of a 30-meter HTS cable, and discusses required test items of HTS cables.

Development of a 100 m, 3-core 114 MVA HTSC cable system

Abstract We have started a project to develop a 100 m 3-core 66 kV/1 kA/114 MVA high temperature superconducting (HTSC) cable system to certify the manufacturing capability and the practicability of an HTSC cable system for use as actual power system equipment. The cable is designed based on the results of a 30 m, 3-core test cable. The cable is composed of a conductor and a shield wound with Ag–Mn sheathed Bi-2223 tapes, electrical insulation with polypropylene laminated paper impregnated with liquid nitrogen and thermal insulation with co-axial corrugated pipes. The three cores are housed in this thermally insulated pipe. The cable has been developed and laid at CRIEPIs test site and long-term tests have been under way since June.

ALBANY HTS CABLE PROJECT LONG TERM IN-GRID OPERATION STATUS UPDATE

High-temperature superconducting (HTS) cable systems are expected to be a solution for improvement of the power grid and three demonstration projects in the real grid are under way in the United States. One of them is the Albany, NY Cable Project, involving the installation and operation of a 350 meter HTS cable system with a capacity of 34.5kV, 800A, connecting between two substations in National Grids electric utility system. A 320 meter and a 30 meter cable are installed in underground conduit and connected together in a vault. The cables were fabricated with 70km of DI-BSCCO wire in a 3 core-in-one cryostat structure. The cable installation of a 320 meter and a 30 meter section was completed successfully using the same pulling method as a conventional underground cable. After the cable installation, the joint and two terminations were assembled at the Albany site. After the initial cooling of the system, the commissioning tests such as the critical current, heat loss measurement and DC withstand volt...

HTS cable design and evaluation in YOKOHAMA Project

HTS cable demonstration project supported by Ministry of Economy, Trade and Industry (METI) and New Energy and Industrial Technology Development Organization (NEDO) has started since FY 2007 in Japan. The target of this project is to operate a 66 kV, 200 MVA HTS cable in the live network of Tokyo Electric Power Company (TEPCO) in order to demonstrate its reliability and stable operation. Various preliminary tests with the short core samples were conducted to confirm the HTS cable design. One of the technical targets in this project is to reduce the AC losses of HTS cable cores. For this purpose, a new type DI-BSCCO wire with twisted superconducting filaments which is named TypeAC is applied in the cable core. A short cable core made with TypeAC wires shows its AC loss is 0.8 W/m/ph at 2 kArms, which is about 1/4 of the one with standard DI-BSCCO wires. Another important target is to manage a fault current. At a preliminary test with the short cable cores, it showed that the cable could manage the through-fault of 10 kA at 2 sec and survived at 31.5 kA at 2 sec. As the electric insulation tests, AC 90 kV for 3 hours and lightning impulse at ±385kV, 3 shots for each were applied to a cable core, successfully. The results of tensile and bending tests showed the cable core has good mechanical properties. The design of the HTS cable for YOKOHAMA project has been completed as well as those of a termination and a joint. A 30-meter HTS cable was manufactured and a 30-meter HTS cable system was installed in SEI facility. The cable system was cooled down and tested to verify its performance before constructing the HTS cable system in YOKOHAMA. This paper describes the design and test results of the 30-meter HTS cable, and also performance test results of the 30-meter cable system.

Development of HTS Cable System for ALBANY Project

High temperature superconducting (HTS) cable is anticipated to transmit a large amount of electricity with a compact size and can reduce the transmission loss and greenhouse gas emission. The Albany project is being undertaken to verify the practicability of a long HTS cable in the real grid by performing a long-term operation test. The cable is 350-meter long and carries 800 A at 34.5 kV between two electric power substations (Menands and Riverside) in Albany, N.Y. [1]. The project is scheduled to run from 2002 to 2007 and is proceeding as planned. The HTS cable and its apparatus were manufactured in Japan, and the cable was shipped to the USA in the middle of August. After it arrives at the site, the cable installation and the apparatus assembly will be carried out sequentially. This system is expected to begin operating early next year after initial cooling. This paper gives an overview and the current status of the development of the HTS cable system.

DESIGN AND EVALUATION OF YBCO CABLE FOR THE ALBANY HTS CABLE PROJECT

The Albany Cable Projects aim is to develop a 350 meter long HTS cable system with a capacity of 800 A at 34.5 kV, located between two substations in the National Grid Power Companys grid. In-grid use of BSCCO HTS cable began on July 20, 2006, and successful long-term operation proceeded as planned. The cable system consists of two cables, one 320 meters long and the other 30 meters, a cable-to-cable splice in a vault, two terminations, and a cooling system. In Phase-II of the Albany project, this autumn, the 30-meter section will be replaced with YBCO cable. The test manufacturing and evaluation of YBCO cable has been carried out using SuperPowers YBCO wires in order to confirm the credibility of the cable design. No degradation of the critical current was found at any stage of manufacture. The fault-current test, involving a 1-meter sample carrying 23 kA at 38 cycles, was conducted under open-bath conditions. The temperature increases at the conductor and shield were comparable to those of the BSCCO ...