Analysis on high frequency attenuation characteristic of HVDC line boundary

The line boundary of high voltage direct current (HVDC) system is composed of dc filters and smoothing reactor, which has attenuation to high frequency signals and can be used to propose novel line protections. Analysis on the high frequency attenuation characteristic of line boundary is presented in this paper. Based on the practical parameters and arrangements of dc filters and smoothing reactor, this paper studies the high frequency attenuation characteristic with different types of dc filter, different arrangements of smoothing reactor, and different components parameters. Results show that HVDC line boundary has large attenuation to high frequency signals and prove the high frequency signals can be used to form novel HVDC line protections.