Research Of The Fault Current Travelling Wave's Inversion In Transmission Lines

Transmission lines have the biggest possibility to have trouble in the power system.If we can repeat the failure's process to achieve the scenario visualization of failure's process in the transmission line,it will be a meaningful thing to fault analysis,fault diagnosis,defending program for lines,accident drills and other aspects.This paper uses the propagation characteristics in frequency domain for waves in transmission lines and the inversion theory to build the inversion model of the fault current travelling waves.The objective function is established by using Wavelet Packet transform and Fast Fourier transform.Then the distributed parameters of the transmission lines such as resistance,inductance,conductance and capacitance can be calculated with the help of Particle Swarm Optimization(PSO)method.Finally,the paper calculates the current travelling waves based with the model of distributed parameters in one detecting point and has a comparison with those are measured in practice to verify the correctness of the model.By using this method,the fault current travelling waves in other places of the line can be calculated.Then this paper presents severial factors that may affect the accuracy of travelling wave's inversion,which are waveform amplitude,sampling accuracy,wave shift,fault point shift,fault location close to the bus,the location of the inverse point and the type of failure.This paper has a verification for these factors by using the method of the fault current travelling wave's inversion,which improves the scopes and conditions of the use of this method,also provides a new method and the data support to the fault analysis and troubleshooting in transmission lines.