110kv Line Distance Protection Study Based On Traveling Wave Theory

Transmission line power transmission system is an important part in modern power system, So the reliability of transmission line has relation to the reliability of the power network, when the fault occurs, the whole transmission system will damage, how to quickly and accurately identify the fault and debug is an important issue, it has important significance for avoiding the device damage and long maintenance time, and improving the power supply reliability of power network.Fault feature of different faults are studied in the paper, and traveling wave theory is used to locate, and phase-mode transform was used to eliminate three-phase coupling, So the mold component is not affected by the frequency of these outside factors, and choosing the correct relative to the accurate fault location is extremely important, using the mode component phase selection and fault location main discriminate tensor, and the use of modular components into the normal amount to achieve differential fault phase selection, after selecting the fault phase, Wavelet transform is used as mathematical analysis tool, wavelet transform singularity theory is applied with the analysis of the characteristics of transient traveling wave fault detection, Fault traveling wave is transformed,using the modulus maximum value method to extract the fault traveling wave head, extracting its first arrived and the first reflection wave first arrival time point, and combining the traveling wave propagation theory to calculate the position of fault point, the distance protection selective action to remove the fault with the fault point location.This paper use the software of electric power system to build a section of transmission line model and change the model parameters, according to different fault type, fault distance and different transition resistance for simulation, the fault data prove the correctness of validation phase selection method and the accuracy of distance measurement.