Coordination Control of Resistive SFCL and Hybrid DC Circuit Breaker in HB-MMC-HVDC System

How to cut off the DC fault current safely to ensure the continuous operation of the half bridge modular multilevel converter based HVDC (HB-MMC-HVDC) under DC faults is a huge challenge. To tackle this problem, the combination of the resistive superconducting fault current (SFCL) and the hybrid DC circuit breaker (CB) is used in this paper. Firstly, the resistive SFCL is to limit the rising rate and level of the DC fault current, and then the hybrid DC circuit breaker is to cut off the DC fault current. Moreover, the coordination control strategy of the resistive SFCL and the hybrid DC CB is proposed based on their operation characteristics. Finally, a case study and simulations of Nan'ao ±160kV three terminal HB-MMC-HVDC system are performed in PSCAD/EMTDC software to validate the effectiveness of the proposed coordination control strategy of the resistive SFCL and the hybrid DC CB.