Fault identification method based on forward traveling wave amplitude feature for HVDC transmission line

A novel fault recognition method, based on forward traveling wave amplitude feature of HVDC transmission line is proposed. The amplitude integration ratio of forward traveling waves within a short time after a fault is used to distinguish internal faults from external faults. For internal faults, the difference of amplitude between forward traveling waves at both ends is mainly related to line attenuation constant and fault location, the ratio of amplitude integration is relatively small. But for external faults, the ratio of amplitude integration is relatively large because forward traveling wave amplitude is affected by reflecion conefficient to a large extent. A large amount of simulation results based on PSCAD/EMTDC indicate that, the proposed fault recognition method can provide rapid and reliable identification between internal faults and external faults under various fault conditions, including different fault locations and high transition resistances.