A Single-End Protection Scheme for Hybrid MMC HVDC Grids Considering the Impacts of the Active Fault Current-Limiting Control

In the hybrid modular multilevel converter (MMC) based high voltage direct current (HVDC) systems, fault can be actively suppressed by itself, which endows a smaller requirement for current-limiting reactors (CLR) and larger time margin detection algorithms, comparing with half-bridge MMC. But robustness to resistance noise disturbance of existing boundary protection schemes will deteriorated small CLRs. Moreover, fast response control change output DC MMC, affects characteristics may cause mal-operation algorithms. Thus, single-end scheme considering impacts active is proposed MMC grids. The traveling-wave under different stages are analyzed evaluate control. addition, coordination strategy versus conditions adopted improve reliability. Various cases in PSCAD/EMTDC simulated verify that method robust resistance, distance, power reversal, AC faults, immune noise.