A novel distance protection scheme using time-frequency analysis and pattern recognition approach

This paper presents a new approach for distance protection of transmission lines using time-frequency analysis. The proposed technique consists of preprocessing the fault current signal samples using hyperbolic S-transform to yield the change in energy and standard deviation at the appropriate window variation. From these two features, a decision of fault or no-fault on any phase or multiple phases of the transmission line can be made. The ground detection is done by a proposed indicator with a threshold value. The fault distance from the relaying point can be accurately estimated using cubic polynomial interpolation technique, Feed forward Neural Network and Adaptive Network Fuzzy Inference System (ANFIS).