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The use of high temperature superconducting (HTS) tapes in a flexible cryostat has been shown to provide great opportunities for the US Navy. The HTS tapes need to be fixed at the ends to provide an electrical connection. Since the ends are rigid but the tapes are contained in a changing environment there is a possibility that the tapes may become twisted and therefore damaged. Twisting is defined in this paper as the rotation of the tape along the length of the tape while the end has no attack-angle. The twisting length and angle of first generation (1G) BSCCO tapes is studied by measuring the voltage drop across the tapes in a liquid nitrogen bath when current is applied. [ABSTRACT FROM AUTHOR]

This paper discusses the full-power testing of a 36.5 MW High Temperature Superconductor (HTS) propulsion motor at the Navy's Land Based Test Site (LBTS) located in Philadelphia, PA. This motor was developed under funding from the Office of Naval Research and passed no-load factory testing at Philadelphia in March 2007. The Naval Surface Warfare Center (Carderock Division - Philadelphia site) designed and installed a test facility at LBTS to support full-power/full-torque testing of the HTS motor delivered to the Navy in 2007. The facility, test plan and full-power and full-torque test results of the HTS propulsion motor are presented. These test results provide the final substantiation that this technology is ready for integration in to a Navy electric drive combatant. [ABSTRACT FROM AUTHOR]

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 Grid's 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 SuperPower's 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. [ABSTRACT FROM AUTHOR]

The US Department of Homeland Security is currently funding the design, development and demonstration of an inherently fault current limiting HTS cable, called Secure Super Grids, under the Hydra project with Con Edison. The cable is 300 m long and is being designed to carry 96 MVA at a distribution level voltage of 13.8 kV. The cable will be built using cable system experience gained by AMSC and Ultera (a Southwire and nkt Cables joint venture) on previous projects. The underground cable will be permanently installed and energized in New York City in 2010. The project is led by American Superconductor who is teamed with Ultera and Con Edison. This paper describes the general goals and design criteria of the project. An overview of the concept of Secure Super Grids and advantages of this type of cable are presented in a grid-based network modeling. In addition, the design issues such as tailoring of the HTS wire to provide adequate thermal stability and electrical properties both under normal operation and during a fault are presented. [ABSTRACT FROM AUTHOR]

The first long length, transmission level voltage, cold dielectric, high temperature superconductor power cable has been successfully installed in the Long Island Power Authority (LIPA) grid. The cable is capable of carrying 574 MVA at a voltage of 138 Ky. Three 600 m long phase conductors were manufactured and shipped to the LIPA site. The installation process included pulling three cables through three separate 600 m long underground conduits and assembly of three terminations at each end. The project has been funded by the US Department of Energy and is led by American Superconductor. The project team is comprised of Nexans, Air Liquide and LIPA. This paper describes the cable system, installation process and an overview of various testing results before and after installation. In addition, details of an initial successful cool-down process are presented. It also includes the performance results in grid operation. [ABSTRACT FROM AUTHOR]