The present application relates to the technical field of fault location of UHVDC transmission, in particular to a single-ended accurate fault location method for UHVDC
transmission system, when single-pole grounding fault occurs in the line, positive and
negative voltage and current signals at the installation position of the protection are collected, line mode and
zero mode voltage reverse
waves are obtained through Kalman-Bell transformation decoupling, the first wave head is positioned by difference and
effective time domain data is intercepted,
S transform is carried out for time-frequency mapping by using adaptive
window width, time-frequency energy redistribution is realized by iterative optimization group
delay fixed point, time direction high convergence time-frequency distribution is obtained, double-mode wave
arrival time is extracted frequency by frequency and modulus
time difference is calculated, initial fault distance sample is obtained by combining frequency variable propagation speed, the probability density
peak value is taken as the final fault location result through non-parametric
kernel density estimation, the present application does not need double-ended communication and synchronization, and greatly improves the wave
arrival time extraction accuracy, anti-interference ability and fault location robustness.