In recent years significant progress has been made in the development of high temperature superconducting (HTS) power devices, in particular cables and fault current limiters. Several field tests of large scale prototypes for both applications have been successfully accomplished and the technologies are getting closer to commercialization. Especially the application of medium voltage HTS systems as replacement for conventional high voltage cable systems is very attractive and offers many advantages. Besides the increased power density there is only a negligible thermal impact on the environment. In addition, HTS cables do not exhibit outer magnetic fields during normal operation and in combination with HTS fault current limiters the operating safety is also increased. Since HTS cables are in general more compact than conventional cables the required right of way is much smaller, the installation is easier, and the required substation space is reduced as well. Especially in congested urban areas dismantling of substations results in prime location space gains which could be sold or used otherwise.
This paper will give an update on the German AmpaCity project, which started in September 2011. The objective of the project is developing, manufacturing and installing a 10 kV, 40 MVA HTS system consisting of a fault current limiter and of a 1 km cable in the city of Essen. Since it is the first time that a one kilometer HTS cable system is installed together with an HTS fault current limiter in a real grid application within a city center area, AmpaCity serves as a lighthouse project. In addition it is worldwide the longest installed HTS cable system. Within the project the development phase was finished in March 2013 with successfully completing the type test of the cable system. Subsequently, all system components were manufactured and the installation on site took about two months finishing at the end of November 2013. Afterwards, the commissioning test of the system was performed in December. In the beginning of March 2014, the system was commissioned into the grid and has since then been supplying energy to the city center of Essen.

The authors would like to thank all their colleagues who contributed to this paper as well as the German Federal Ministry of Economics and Technology which is supporting the pilot project in Essen under the grants 03ET1055A, 03ET1055B, 03ET1055C and 03ET1055D.

American utilities paid close attention to the possible application of superconductivity to power deployment throughout the decade following the Bednorz-Mueller-Chu discoveries of superconducting materials (HTSC) eventually operating above the boiling point of liquid nitrogen. Several previous attempts (1960s and 70s) to demonstrate power applications, especially focusing on cables, had been carried out using “low” temperature (liquid helium) materials successfully applied to hadron colliders, magnetic resonance imaging (MRI), and laboratory instrumentation; however, no serious attempts to commercialize such efforts were undertaken. We focus on the first project in the United States to explore the practicalities, both technical and economic, to attempt utilization of HTSC cables in an operating utility. This challenge was initiated by Pirelli Cables, then and historically the major supplier of underground transmission cables in the US, and Detroit Edison, the largest Michigan municipal electric utility, with technical advisement and assessment from the Electric Power Research Institute and the Los Alamos National Laboratory. American Superconductor was chosen by Pirelli to be its wire supplier. It is important to point out that the partnership was driven by private initiative, and not by state or federal subsidies. The “business cases” were 1) for Pirelli the development of “triple capacity” ac transmission cables deploying current rights-of-way unique to US utilities, and 2) for Detroit Edison the expectation of a possible load doubling in central Detroit to service commerce expansion arising as a side effect of emerging legalized gambling in nearby Windsor, Ontario. Although the project encountered technical difficulties during cable testing at a Detroit Edison substation, these were minor in nature, and the project did not go forward as result of deregulation (breakup of Detroit Edison) and the decision by Pirelli that projected return-on-investment, not only in the United States, but internationally, would be too small to pursue. Although the American electricity enterprise is based on the concept of investor-owned private utilities (> 160), as opposed to Europe, these “lessons learned” may prove useful as the European Union continues its mostly government-sponsored, and well-focused, initiatives to bring the benefits of HTSC “to the people.”

The National Electric Energy Agency of Brazil (ANEEL) demanded in 2010 a Project in new technologies for power transmissions, considering applied superconductivity. In response, four main power utilities (CEMIG, CTEEP, TBE and, TAESA energy companies) and the Federal Rural University of Rio de Janeiro (UFRRJ) proposed and are currently developing the PeD_D712:SUPERCABO Project. The main goals are to project, to build and to test in field a prototype of HTS power cable with the following characteristics: rated current = 1 kArms; rated operating voltage = 69kV; rated power = 119,5 MVA; heat intake = 1W/m; 3-phase coaxial with cold dielectric; hollow inner former with liquid N2 flow; four conducting layers with 10 HTS 2G tapes each; shielding layer with 50 HTS tapes; PPLP dielectric; cable length = 10 m. We present in this work the results achieved up to date in that project: cable design, tapes characterization, facilities for development and test of that HTS Cable at the Laboratory for Materials and Devices with Superconductors (LMDS) at UFRRJ, as well the performance of that cable, evaluated with computational simulations.

P&D ANEEL D712: SUPERCABO Project, CEMIG D, CEMIG GT, CTEEP, TAESA, TBE, UFRRJ and FAPUR for financial support.

High Temperature Superconducting (HTS) cables can transmit large amounts of electricity in a compact size with minimal losses. Therefore, it expects to save the construction cost of underground lines in urban areas and decrease transmission losses. Several HTS cable systems have recently been demonstrated in networks around the world, and full-scale commercialization is expected in the near future. In Japan, the development of compact HTS cables suitable for urban deployment has been underway since the early 1990s. In 2007, a national project was begun to verify their operational performance and long-term reliability in the grid. An HTS cable 240 m long was installed at the Asahi substation of the Tokyo Electric Power Company (TEPCO) in Yokohama; then a joint, terminations and a cooling system were constructed in 2011. After successful performance tests, the cable was connected to the grid for the first time in Japan, and started to deliver electricity to 70,000 households in October 2012. This trouble-free in-grid service was continued for over a year. We can conclude that the HTS cable system performs well and has the stability required for long-term in-grid operation.

This work was supported by the Japanese Ministry of Economy, Trade and Industry (METI) and the New Energy and Industrial Technology Development Organization (NEDO).

BEST PATHS (acronym for “BEyond State-of-the-art Technologies for rePowering Ac corridors and multi-Terminal HVDC Systems”) is a collaborative project within the FP7 framework of the European Commission that includes an MgB₂-based power transmission line among its five constituent demonstrators. Led by Nexans and bringing together transmission operators, manufacturers and research organizations, this project aims at validating the novel MgB₂ technology for very high power transfer. CIGRÉ recommendations will be used to take into account the current international practices. The project foresees the development of a monopole cable system operating in helium gas in the range 5 to 10kA / 200-320 kV, corresponding to a transmitted power from 1 to 3.2 GW. The main research and demonstration activities that will be addressed over the four-year project duration are: manufacturing of MgB₂ wires and of the cable conductor, manufacturing of the HVDC electrical insulation of the cable, cryogenic system for helium gas, electromagnetic field analysis, design and construction of a prototype electrical feeding system including terminations and connectors, testing of the demonstrator, grid connection procedures and integration of a superconducting link into a transmission grid, and last but not least, a socio economic analysis of the MgB₂ power transmission system. An overview of the project will be presented at the meeting, including the partners and their roles, the main tasks and challenges, as well as preliminary results after one year of activity.

This work is supported by the DGA (French delegation for ordnance) under the BOSSE project in collaboration with Sigmaphi and the Institut Saint Louis.

Since it is an urgent issue to reduce global carbon-dioxide in the world, the environmentally friendly renewable energy should be used as a large amount of the electric power. It is important to compensate fluctuating power produced by renewable energy, such as wind turbine and photovoltaic, because a large amount of the fluctuating power will cause grid power network unstable. We proposed an advanced superconducting power conditioning system (ASPCS) composed of a hybrid energy storage system connected to renewable energy sources. The hybrid storage system is composed of a Fuel Cell - Electrolyzer (FC-EL) system and SMES cooled by liquid hydrogen (LH2) from a LH2 station for vehicles. The ASPCS has functions of compensating the rapidly changing parts of the fluctuating power by SMES that has quick response and a lot of repeatable cycles, and slowly changing parts by FC-EL that has moderate response and large capacity. The SMES is wound with HTS superconductor and cooled by LH2 through a thermo-siphon indirectly cooling system to keep the system safe. In order to demonstrate the compensation operation of the renewable fluctuating power, we designed and fabricated a small scale ASPCS facility connected with a 1 kW class photovoltaic system. The hybrid storage system was composed of 10 kJ BSCCO SMES and 1 kW class FC-EL system. The test results show that the fluctuating components of the PV power are completely compensated by controlling the hybrid storage system.

This work is partially supported by the Advanced Low Carbon Reduction Technology R&D (ALCA) of the Japan Science and Technology Agency.