Sizing Methodology for Superconducting Fault Current Limiters in HVDC Grids

The present paper introduces a design methodology for superconducting fault current limiters in HVDC grids, regarding the dimensions of the superconducting element. The selection of the dimensions comprises different approaches. This way, thermal, maximum electric field and protection requirements are considered. The proposed sizing approach is applied for the protection of a four-terminal HVDC grid using fault current limiters in series with HVDC circuit breakers. The performance of the superconducting circuit breaker is assessed under most severe faults, based on maximum fault current levels. Thus, the most adequate parameters for the superconducting fault current limiter are evaluated. Based on the present work, it can be concluded that the thermal criterion is the most restrictive one for the HVDC grid under study.