US 12,265,112 B2
Three-terminal power line fault location and correction system and method
Jui-Nien Chou, Taipei (TW); Shun-Pin Chen, Taipei (TW); and Jen-Chung Chen, Taipei (TW)
Assigned to TAIWAN POWER COMPANY, Taipei (TW)
Filed by Taiwan Power Company, Taipei (TW)
Filed on Jul. 14, 2022, as Appl. No. 17/864,880.
Claims priority of application No. 110131693 (TW), filed on Aug. 26, 2021.
Prior Publication US 2023/0067848 A1, Mar. 2, 2023
Int. Cl. G01R 31/08 (2020.01)
CPC G01R 31/088 (2013.01) [G01R 31/085 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A three-terminal power line fault location and correction system, comprising:
three terminal devices, a first power line, a second power line and a third power line, wherein the three terminal devices are respectively connected to a divergence point through the first, second and third power lines, so that the three terminal devices are respectively positioned at three terminals of the first, second and third power lines, there is respectively an actual distance between the terminal device and the divergence point, wherein each of the terminal devices comprises a relay, a current transformer and a potential transformer; and
an electronic device electrically connected with the terminals devices, the electronic device comprises one or more processing units and a memory unit electrically connected to each other, the one or more processing units can access the data stored in the memory unit;
wherein, when a fault occurs at a fault position on one of the first, second or third power lines, the following procedures are executed:
each of the three terminal devices respectively records an abnormal voltage and an abnormal current caused by the fault at the secondary side of the current transformer and the potential transformer so as to respectively obtain the line impedances of the first, second and third power lines;
each of the relays compares the line impedance with the average impedances of the first, second and third lines, respectively, so as to after calculation, respectively, so as to after calculation, respectively obtain a fault distance between the three relays and the fault position; and
based on the fault distances obtained by the relays and the actual distances between the terminal devices and the divergence point, the one or more processing units of the electronic device corrects the fault distance as follows so as to narrow the fault location range:
the corrected fault distance of any one of the terminals devices=(an actual distance between the any one of the terminal device and a divergence point+a maximum value function of actual distances between the other two terminal devices and the divergence point) * the fault distance corresponding to the any one of the terminal device/(the fault distance corresponding to the any one of the terminal device+a corresponding fault distance with respect to a maximum value function of the actual distances between the other two terminal devices and the divergence point).