FEEMD-based Traveling Wave Protection For The Traction Network Of The Through-type In-phase Power Supply System

With the rapid development of China's economy,Railway traction power system developed from the original steam engine and the internal combustion engine into the electrification era.With the concept of high speed and heavy load deeply rooted in the hearts of the people,the electric power quality requirements for electrified railways are more stringent.The existing electrified railway has the problems of electric energy quality such as phase separation and negative sequence,which affect the further development of railway.Aiming at the problem of negative sequence and equal electric component,the technology of in-phase power supply proposed by experts and scholars is expected to solve the phase problem.The current adaptive distance protection widely used in electrified railway is difficult to meet the complex protection configuration.It is suitable and necessary to apply the traveling wave protection to the feeder protection of the traction network of the traveling wave power supply system of the traveling wave power supply system,which has important theoretical and practical significanceIn this thesis,PSCAD/EMTDC simulation software was used to establish the simulation model of the direct power supply system with in-phase through-type traction brought back streamlines.The model mainly included ac-dc-ac transformation traction substation and ac-dc-ac CHR2 electric locomotive.Because the simulation model is unbalanced line,a new phase-mode transformation matrix based on line parameters is introduced to decouple and simplify the selection of fault characteristic tr aveling wave.The propagation characteristics of traveling wave in traction substation,electric locomotive and other components are analyzed.Based on the principle of traveling wave protection and the connection type of in-phase traction direct power supply system,three protection methods of traveling wave amplitude comparison direction protection,traveling wave differential protection and traveling wave direction comparison longitudinal protection are put forward.A large number of simulation tests are carried out for different fault conditions,and the simulation results show that the three types of protection are able to quickly and reliably identify the faults inside and outside the traction network area,and are basically not affected by the initial fault Angle,grounding resistance,fault location and other related factors,with high accuracy and reliability and good engineering application prospects.