DOI:10.35833/MPCE.2019.000095 Transmission Line Distance Protection Under Current Transformer Saturation Page view: 0        Net amount: 101 Author: Yuping Zheng1,2,Tonghua Wu1,2,Feng Hong4,Gang Yao4,Jimin Chai1,3,Zhinong Wei1 Author Affiliation: 1.College of Energy and Electrical Engineering, Hohai University, Nanjing 210098,China;2.State Key Laboratory of Smart Grid Protection and Control, NARI Group Corporation, Nanjing 211106, China;3.Changzhou Institute of Technology, Changzhou 213032, China;4.State Key Laboratory of Smart Grid Protection and Control, NARI Group Corporation, Nanjing 211106, China Foundation: This work was supported by Science and Technology Program of State Grid Corporation of China “Research on Fault Coupling Characteristics and New Protection Principle of AC/DC Hybrid Power Grid”. Abstract: Conventional transmission line distance protection approaches are subject to malfunction under reverse fault-induced current transformer (CT) saturation for the typically employed breaker-and-a-half configuration. This paper addresses this issue by proposing a new distance protection approach that combines the blocking and unblocking criteria of distance protection based on the values of incomplete differential current, operation voltage, and current harmonic content. The proposed approach is verified by theoretical analysis, dynamic simulation testing, and field operation to ensure that the obtained distance protection is reliable and refrains from operating unnecessarily under reverse fault-induced CT saturation in the breaker-and-a-half configuration. Meanwhile, the proposed approach is demonstrated can operate reliably when forward faults occur or various reverse faults are converted to forward faults. Keywords: Breaker-and-a-half configuration ; current transformer (CT) saturation ; distance protection ; power frequency variation ; operation voltage Received:October 12, 2019               Online Time:2021/01/22 View Full Text       Download reader