Traveling Wave based Adaptive Auto-reclosing and Fault Location for Three-terminal Mixed Lines

摘要

This paper presents an adaptive auto-reclosing protection scheme and fault position identification technique for three-terminal mixed line system using faulted section identification (FSI) information. The mixed line system is a power transmission network containing both overhead line (OHL) and underground cable (UGC). In this approach, FSI index is computed using the incident traveling wave (TW) arrival time measured at each terminal, length and wave speed of the section. Precise fault location (FL) can be computed using FSI and TW incident wave arrival time measured at each terminal. TWs are extracted from the current signal measured at each terminal using a notch filter and special sensors are not required. The technique is tested using PSCAD/EMTDC simulation tool and shows that the technique classifies the precise faulted section and locate the fault position. The proposed technique does not require tap point measurements and it saves the communication and sensor cost for practical applications.