Development of Superconducting Cable With Energy Storage Function and Evaluation of its Functionality in DC Microgrid With Renewable Energy Sources

Abstract

We propose a superconducting cable with energy storage and its operation in a DC microgrid as a measure to mitigate output fluctuations of renewable energy sources. This not only enables high-speed and high-power charge-discharge operation, which is difficult with conventional energy storage devices, but also minimizes the additional equipment required for energy storage because it also serves as power transmission. In the previous study, we reported its effectiveness through conceptual cable design and simple numerical simulation. In this study, we experimentally verified such functionality by hardware-in-the-loop simulation with the use of small model cables and clarified the effects on DC microgrids by numerical simulation reflecting the experimental results. The results showed that in a 10 MW scale microgrid, a superconducting cable with 40 MJ of stored energy could fully compensate for second-scale fluctuations which could not be compensated without it. Furthermore, a superconducting cable with 1 GJ of stored energy eliminated the even need for other batteries for such a microgrid.