TY - JOUR
T1 - An Improved Non-Unit Traveling Wave Protection Method with Adaptive Threshold Value and Its Application in HVDC Grids
AU - Zhang, Chenhao
AU - Song, Guobing
AU - Wang, Ting
AU - Dong, Xinzhou
N1 - Publisher Copyright:
© 1986-2012 IEEE.
PY - 2020/8
Y1 - 2020/8
N2 - The performance of the traditional derivative-based non-unit traveling wave protection (TWP) in high voltage dc (HVDC) grids shows the problem of low-sensitivity when high-impedance faults occur. In this article, the characteristics of the fault initial traveling wave are analyzed first, two conclusions can be drawn: i) the distortion degree of the fault initial traveling wave is related to the fault location, ii) the amplitude of the fault initial traveling wave is related to the fault impedance. Then a zero-sequence current fitting method is proposed to obtain parameters respectively reflecting fault impedance and fault distance. When a fault occurs, a fault information extraction method based on the fitting parameters will give the estimation interval of the fault impedance, which provide reference for the adaptive threshold value selection of TWP. In this way, the influence of the fault impedance on TWP can be eliminated. A ±400 kV modular multilevel converter (MMC) HVDC grid is built in PSCAD/EMTDC. The verification of the proposed method considers different installation positions of the current limit inductor. The simulation results show that the proposed method can fast and correctly identify the dc line faults and effectively improves the protection sensitivity in detecting high-impedance faults.
AB - The performance of the traditional derivative-based non-unit traveling wave protection (TWP) in high voltage dc (HVDC) grids shows the problem of low-sensitivity when high-impedance faults occur. In this article, the characteristics of the fault initial traveling wave are analyzed first, two conclusions can be drawn: i) the distortion degree of the fault initial traveling wave is related to the fault location, ii) the amplitude of the fault initial traveling wave is related to the fault impedance. Then a zero-sequence current fitting method is proposed to obtain parameters respectively reflecting fault impedance and fault distance. When a fault occurs, a fault information extraction method based on the fitting parameters will give the estimation interval of the fault impedance, which provide reference for the adaptive threshold value selection of TWP. In this way, the influence of the fault impedance on TWP can be eliminated. A ±400 kV modular multilevel converter (MMC) HVDC grid is built in PSCAD/EMTDC. The verification of the proposed method considers different installation positions of the current limit inductor. The simulation results show that the proposed method can fast and correctly identify the dc line faults and effectively improves the protection sensitivity in detecting high-impedance faults.
KW - Adaptive threshold value
KW - current fitting
KW - fault information extraction
KW - HVDC grid
KW - non-unit traveling wave protection
UR - https://www.scopus.com/pages/publications/85083724866
U2 - 10.1109/TPWRD.2019.2954599
DO - 10.1109/TPWRD.2019.2954599
M3 - 文章
AN - SCOPUS:85083724866
SN - 0885-8977
VL - 35
SP - 1800
EP - 1811
JO - IEEE Transactions on Power Delivery
JF - IEEE Transactions on Power Delivery
IS - 4
M1 - 8907453
ER -