Title
DC Fault Detection in Meshed MTDC Systems Based on Transient Average Value of Current
Abstract
It is of great significance for a voltage source converter (VSC)-based multiterminal dc (MTdc) grid to isolate the dc fault lines within several milliseconds after dc fault. Existing protection schemes and fault analysis methods are mainly based on the numerical simulations, which lack the theoretical analysis. In this paper, a high-frequency (HF) equivalent model of VSC-based MTdc grid that is utilized for initial dc fault current calculation is first proposed. In the proposed model, the parallel connected capacitors of VSCs are regarded as short-circuited, and the initial fault current calculation of the fault dc line and the healthy dc line can be reduced as a simplified <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RL</italic> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RLC</italic> circuit. Accordingly, a novel dc fault detection method for VSC-based MTdc system is further proposed. In the proposed approach, the primary detection utilizes the transient average value of line current and the fault dc line can be identified quickly with only one-end information. In addition, the errors between the transient fault current calculation based on the distributed parameter line model and the lumped parameter line model are also evaluated. Numerous simulation studies carried out in PSCAD/EMTdc have demonstrated that the proposed HF equivalent model can be utilized for initial dc fault analysis of VSC-MTdc system and the proposed protection scheme is effective under different fault locations and high fault resistances. Compared with the traditional protection schemes based on rate of change of current, the proposed one requires relatively low sampling frequency and low computation burden, and has high fault resistance tolerance ability and high robustness with respect to the missing data.
Year
DOI
Venue
2020
10.1109/tie.2019.2907499
IEEE Transactions on Industrial Electronics
Keywords
Field
DocType
Circuit faults,Fault currents,Inductors,Transient analysis,Capacitors,Fault detection,RLC circuits
Capacitor,Control theory,Fault detection and isolation,Voltage source,Inductor,Robustness (computer science),Fault (power engineering),Engineering,RLC circuit,Grid
Journal
Volume
Issue
ISSN
67
3
0278-0046
Citations 
PageRank 
References 
3
0.47
0
Authors
5
Name
Order
Citations
PageRank
Yujun Li110418.20
Jiapeng Li2184.13
Liansong Xiong331.48
Xian Zhang430.47
Zhou Xu56615.44