Open AccessSingle‐phase high‐impedance fault protection for low‐resistance grounded distribution network
Author(s) -
Tang Tao,
Huang Chun,
Hua Leng,
Zhu Jiran,
Zhang Zhidan
Publication year - 2018
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2017.1547
Subject(s) - overcurrent , transformer , electrical impedance , amplitude , phase angle (astronomy) , high impedance , fault (geology) , engineering , electronic engineering , electrical engineering , voltage , physics , quantum mechanics , astronomy , seismology , geology
After a single‐phase high‐impedance fault (HIF) for low‐resistance grounded distribution network (LRGDN) occurs, fault current level is very low and cannot be detected by conventional overcurrent relays. In this study, composite power of each feeder which is composed of complex power and its conjugate is defined, and a HIF protection method based on the composite power of each feeder is presented. For a sound feeder, the phase angle of the composite power is equal to 0, and its amplitude is approximately 0. However, for the faulty feeder, the phase angle of the composite power is π , and its amplitude is much greater than 0. Base on the above significant difference, the protection criterion for HIFs in the LGRDN can be obtained. Theory analysis and simulation results show that the proposed method does not need to check the polarities of the zero‐sequence current transformers and is able to remove faulty feeder reliably. Besides, the protection can accurately operate for HIFs in the case of noise interference and unbalanced current. The experimental results based on RTDS also show the efficiency of the proposed method.