Superconducting magnetic energy storage and fault current limiters-projects, considerations, and outlook

Novel technologies such as superconducting magnetic energy storage (SMES) and nondisruptive fault current limiters (FCL) are both of increasing interest to the electric power industry. The latter will have to cope with significant technical challenges due to new restrictions on plans to expand transmission capabilities, the increasing demand for better power quality, and other reasons in the future. This paper reviews the fundamental operating principles of SMES and FCL, provides and overview on the status of research projects worldwide, and outlines some of the technical challenges still to be overcome for product development. Several aspects of SMES and FCL applications are discussed from the utility´s point of view. Furthermore, estimated costs are presented for SMES and FCL. It is concluded that both technologies, while still too costly for a wide marked introduction, may already be beneficial for selected pilot applications such as, for SMES, custom power enhancement or, for FCL, closing bus ties and connecting independent energy providers (IEPs) to the transmission grid.