TY  - JOUR
AU  - Liu, Ningning
AU  - Li, Yongli
AU  - Chen, Xiaolong
AU  - Liu, Jiashuo
AU  - Zhu, Yuchen
PY  - 2026
TI  - Fault Voltage Amplitude Coefficient-based Protection for DC Lines in Hybrid Multi-terminal DC System
JO  - CSEE Journal of Power and Energy Systems
SN  - 2096-0042
SP  - 851
EP  - 863
VL  - 12
IS  - 2
AB  - The article deduces analytic expression of voltage travelling wave for hybrid cascaded DC system and puts forward protection based on amplitude coefficients of line-mode fault-component voltage (LFCV). By analyzing time-domain expressions of fault voltage travelling waves, it is derived that under internal faults, for the head of line, the ratio of two amplitude coefficients of the LFCV is 1:2, while for the end of line, the ratio of two amplitude coefficients of the LFCV is 1:0. Then, it is further derived that under internal faults, for either side of line, the sum of two amplitude coefficients of the LFCV is far less than 0. However, under external faults, for the near faulty terminal of the line, the ratio of two amplitude coefficients of the LFCV is 1:−1; thus, the sum of two amplitude coefficients is 0. Therefore, the amplitude coefficients of LFCV can be utilized to distinguish the internal fault from the external fault. Simulation verifies that the method can reliably discriminate the internal and external faults even with high fault resistances and has high robust, ss confronting noise interference.
UR  - https://doi.org/10.17775/CSEEJPES.2023.02620
DO  - 10.17775/CSEEJPES.2023.02620