Study of 160 kV/1 kA R-SFCL Design and Application in Nanao MMC–MTDC Project

The use of a resistive-type superconducting fault current limiter (R-SFCL) in the nanao modular multilevel converter based multiterminal high-voltage direct current transmission project (MMC–MTdc) is the first of its kind over the world. There were no relevant development and operational experience to support the construction of this project. In response to the difficulties in implementation, the corresponding methods were straightened out in this article. These contributions include 1) proposal of an iterative optimization calculation method for the time-varying quenching resistance of the R-SFCL; 2) the establishment of a simulation platform based on PSCAD/EMTDC for MMC–MTdc system with a nonlinear R-SFCL model; 3) two-group with three-outlet-terminal topology scheme for R-SFCL device; 4) dc-side short-current calculation and short-current suppression rate analyses for MMC–MTdc with the developed R-SFCL; and 5) steady-state operation, insulation performance, and power switching tests of the developed R-SFCL. Conclusively, the feasibility of the R-SFCL prototype is verified with the simulation and engineering practice of pole-to-ground test in the nanao MMC–MTdc system. In conclusion, the presentation of these research contents and conclusions illustrates the future value of industrial experience in the design and operation of R-SFCL MMC–MTdc systems.