A Novel Inverter Topology on Mitigation of Commutation Failure in LCC-Based HVDC Systems

With more applications and larger transmission capacity of LCC-HVDC transmission systems, commutation failure has attracted more attention. In view of this problem, existing methods pay less attention to commutation failures caused by severe short-circuit faults on AC or DC side. Thus an auxiliary method is needed as a supplement. This paper develops a method for SFCLs to suppress commutation failure in HVDC transmission system. A strategy based on SFCLs is designed as an auxiliary method to mitigate commutation failures caused by severe short-circuit faults. The proposed method is based on the proposed module. The operating principles are presented. The performance of the proposed method is validated by simulation results in PSCAD. The simulation results show that the proposed method can effectively prevent the first commutation failure caused by severe short circuit fault.