Abstract:Traveling wave protection is an important part of HVDC transmission line protection system. In order to analyze the reasons for the lack of reliability of Siemens traveling wave protection in existing projects, based on traveling wave protection logic used in practical projects, a Siemens traveling wave protection model considering signal broadening is established. On this basis, the adaptability of Siemens traveling wave protection under different types of internal and external grounding faults is analyzed, and the reasons for the lack of adaptability are analyzed. The simulation results show that the signal broadening improves the reliability of Siemens traveling wave protection to a certain extent, but the voltage variation criterion in the protection criterion greatly affects its selectivity for high resistance faults in the area and low resistance faults outside the area.