A Novel Transmission Line Fault Location Method Based on Time Frequency Correlation

The fault location method based on the transient traveling wave has been widely used in power grid. The location accuracy and reliability of traveling wave fault location may get affected by some factors including: length error of transmission line, timing error, secondary signal cable in substation. The paper proposes a novel fault location method based on the time-frequency correlation of the fault data collected from two ends of transmission line. It takes advantage of the symmetry and similarity of reflected waves at both ends while the resonance and the reflected waves of adjacent lines are not correlated with each other. Through time-frequency correlation analysis at both ends, the influence of interference and resonance is suppressed, reliability of reflected wave identification and fault location, as well as accuracy of fault location are improved. Effectiveness of the method is verified by simulation and field data.