US 12,394,979 B2
Method and system for adaptive single-phase reclosing of wind farm AC transmission lines
Hongchun Shu, Kunming (CN); Yue Dai, Kunming (CN); Cong Li, Kunming (CN); Yutao Tang, Kunming (CN); Hongfang Zhao, Kunming (CN); Yiming Han, Kunming (CN); Kaiqing Tian, Kunming (CN); and Jun Dong, Kunming (CN)
Assigned to KUNMING UNIVERSITY OF SCIENCE AND TECHNOLOGY
Filed by KUNMING UNIVERSITY OF SCIENCE AND TECHNOLOGY, Kunming (CN)
Filed on Nov. 13, 2024, as Appl. No. 18/945,578.
Claims priority of application No. 202311507174.2 (CN), filed on Nov. 14, 2023.
Prior Publication US 2025/0158401 A1, May 15, 2025
Int. Cl. H02J 3/00 (2006.01); G01R 31/52 (2020.01); H02J 3/38 (2006.01); H02J 13/00 (2006.01)
CPC H02J 3/0012 (2020.01) [H02J 3/00125 (2020.01); H02J 3/381 (2013.01); H02J 13/0004 (2020.01); G01R 31/52 (2020.01); H02J 2203/20 (2020.01); H02J 2300/28 (2020.01)] 8 Claims
OG exemplary drawing
 
1. A single-phase adaptive reclosing method for an AC transmission line of a wind farm, where no parallel reactor is installed on either side of the AC transmission line, the single-phase adaptive reclosing method comprising:
sampling a fault phase voltage using a signal acquisition device;
subjecting the sampled fault phase voltage to short-time Fourier transform to extract a fundamental frequency voltage component amplitude Uf(k);
subjecting the extracted fundamental frequency voltage component amplitude of the fault phase voltage to differential amplification processing to obtain Ud(k);
setting a maximum discrimination time limit tmax and constructing a fault nature identification criterion, wherein:
the fault nature is judged as the transient fault if within a certain time window Udi(m)>ε, ε being a set threshold, otherwise the fault nature is judged as a permanent fault; and
performing a fault nature identification using the fault nature identification criterion wherein:
if the fault nature is identified as a permanent fault, locking out the reclosing device; and
if the fault nature is identified as a transient fault, Calculate a fault disappearance time td, and determine a reclosing time tc through the fault disappearance time, and perform reclosing at time tc, wherein, calculating the fault disappearance time td, and determining the reclosing time tc through the fault disappearance time, and performing reclosing at time tc comprises:
calculating the fault disappearance time td according to sliding times i of a sampling time window Ts2 obtained by constructing the fault nature identification criterion and a mutation sampling point m as follows:

OG Complex Work Unit Math
where Tc is the interval between two adjacent sampling points, and is calculated as follows:

OG Complex Work Unit Math
where fs is the signal sampling frequency; and
using the calculated fault disappearance time td, combined with an arc channel insulation recovery time t to determine the reclosing time tc, and output a closing signal wherein the reclosing time tc is determined as follows:

OG Complex Work Unit Math