Analysis And Research On Traveling Wave Fault Location Method Based On Phase-mode Transformation Of Traction Network

With the increase of high-speed railway passenger volume and the continuous increase of train speed,the requirements on traction uninterrupted power supply capability become increasingly stringent.The accurate fault location of traction network directly affects the safe and reliable operation of traction power supply system.At present,the railway administration mainly adopts the impedance method for short circuit fault location of traction network.This method is simple and economic,but the precicion is low and easily affected by the transition resistance and other factors.Therefore,this thesis puts forward traveling wave fault location method based on phase-mode transformation of traction network and analyses and studies on the location algorithm,collecting devices of fault signal and filtering algorithm.The main content are as follows:Firstly,this thesis analyses the structure and power supply mode of traction network,discusses the difference between traction network and three-phase electric power system and puts forward the idea that traditional phase-mode transformation matrix is not suitable for unbalanced traction power supply system.Based on the theory of phase-mode transformation,this paper deduces the solving process of phase-mode transformation matrix which is suitable for traction system.Secondly,this thesis puts forward the traveling wave fault location algorithm that uses the phase-mode transformation for electromagnetic decoupling on the basis of phase-mode transformation matrix of traction system.Taking the specific parameters of traction network in the railway as the calculation data,the fault location algorithm is modeled and tested by software ATP,including traction transformer,autotransformer,a kind of locomotive and integrated traction network line.Simulation results show that the ranging accuracy of traveling wave fault location algorithm proposed by this thesis is high,and is not affected by fault location,short-circuit grounding resistance,fault phase angle and other factors.And the algorithm reduces the amount of calculation.Thirdly,for the possible influence on the ranging accuracy of traveling wave fault location algorithm,the electromagnetic voltage transformer as traveling wave acquisition device is analyzed.By simulation modeling of distributed parameters of voltage transformer,the transfer characteristic of voltage transformer about impact signal and fault signal is researched.On this basis,considering the main influencing factors such as traction power supply mode,types of short circuit fault,electric locomotive,fault location,the simulation model of voltage transformer is applied to traction lines for simulation experiment.The result shows that transfer characteristic of voltage transformer for traveling wave signal has no influence on traveling wave fault location algorithm.Lastly,according to the noise of voltage traveling wave generated by the signal acquisition device,the filtering method based on EKF is used to filter the signal.Compared with the wavelet method and Wiener filtering algorithm,EKF filtering method has the the best filtering effect,will not cause time migration of catastrophe point and can avoid the error of traveling wave fault location method.The test results show that traveling wave fault location algorithm which is based on the phase-mode transformation matrix of traction system is effective and can be used as the theoretical basis of related fault location products.