Study of Resistive SFCL for Stability Increase of BTB-VSC-HVDC System Based on Virtual Synchronous Generator Control Strategy

For a back-to-back voltage-source-converter HVDC (BTB-VSC-HVDC) system using virtual synchronous generator (VSG) control, it enables more adaptable voltage and frequency support for the main network. In this article, the investigation of the resistive superconducting fault current limiter (R-SFCL) for increasing the BTB-VSC-HVDC's stability under faults is carried out. Firstly, the topological structure and control scheme of the BTB-VSC-HVDC are expatiated. Then, the influence mechanism of cooperating with the R-SFCL and the VSG controller on the power angle stability (PAS) is explored from an energy balance perspective, where the R-SFCL's effects on boosting the VSC's low-voltage ride-through (LVRT) functionality are considered. In light of the MATLAB platform, a detailed digital model of ±420 kV BTB-VSC-HVDC incorporating R-SFCL is created, and the approach validation of coordinating the R-SFCL as well as the VSG controller to address different fault scenarios is implemented. The simulation findings confirm the R-SFCL's efficacy in dissipating the imbalanced power in the BTB-VSC-HVDC and lifting the LVRT behaviors of the VSC. As the efficient coordination of the R-SFCL and the VSG controller in moderate and serious faults, not only the AC voltage drop is ameliorated, but also the PAS of the demonstrated system is visibly increased.