TY - JOUR
T1 - Non-unit protection method for boundary-component-free MTDC systems using normalized backward traveling waves
AU - Xie, Fan
AU - Liu, Le
AU - Hao, Zhiguo
AU - Wang, Ting
AU - Yang, Songhao
AU - Lekić, Aleksandra
AU - Popov, Marjan
PY - 2025
Y1 - 2025
N2 - The performance of existing protection methods for multi-terminal direct current systems depends on the availability and sizes of boundary components. To overcome the limitation, this paper proposes a non-unit DC line protection method based on the normalized backward traveling waves (BTWs) of the 1-mode voltage. Firstly, traveling wave propagation characteristics are analyzed, and a rationalization approach based on vector fitting is proposed. Next, the analytical expressions of normalized BTWs are derived, with the negative correlation between them and fault distance proved. Then, the derivative-free conjugate gradient algorithm is utilized for amplitude fitting and normalization calculation. Finally, a non-unit protection method using the normalized BTWs is developed. The performance is validated for both electromagnetic transient PSCAD/EMTDC and real-time digital RSCAD/RTDS simulation. The results demonstrate that the proposed method can accurately identify faults with various fault resistances and locations without requiring boundary components and high sampling frequencies, and it is robust against noise disturbances.
AB - The performance of existing protection methods for multi-terminal direct current systems depends on the availability and sizes of boundary components. To overcome the limitation, this paper proposes a non-unit DC line protection method based on the normalized backward traveling waves (BTWs) of the 1-mode voltage. Firstly, traveling wave propagation characteristics are analyzed, and a rationalization approach based on vector fitting is proposed. Next, the analytical expressions of normalized BTWs are derived, with the negative correlation between them and fault distance proved. Then, the derivative-free conjugate gradient algorithm is utilized for amplitude fitting and normalization calculation. Finally, a non-unit protection method using the normalized BTWs is developed. The performance is validated for both electromagnetic transient PSCAD/EMTDC and real-time digital RSCAD/RTDS simulation. The results demonstrate that the proposed method can accurately identify faults with various fault resistances and locations without requiring boundary components and high sampling frequencies, and it is robust against noise disturbances.
KW - Derivative-free conjugate gradient algorithm
KW - Multi-terminal DC system
KW - Non-unit protection
KW - Traveling wave
KW - Vector fitting algorithm
UR - http://www.scopus.com/inward/record.url?scp=85209647401&partnerID=8YFLogxK
U2 - 10.1016/j.ijepes.2024.110370
DO - 10.1016/j.ijepes.2024.110370
M3 - Article
AN - SCOPUS:85209647401
SN - 0142-0615
VL - 164
JO - International Journal of Electrical Power and Energy Systems
JF - International Journal of Electrical Power and Energy Systems
M1 - 110370
ER -