High Harmonic Resonance Characteristics Analysis And Suppression Study On Complex Traction Network

With the development of railways and the growing demand of people for travel,the operating mileage of electrified railways has also continued to increase,and the routes have become complex.Many electrified railway lines have stations,locomotive depots,reception-departure yard,these sections not only have a large number of track ways and complicated TN structures,but also a large number of locomotives here,they may form a wide harmonic resonance band.Harmonic current generated by locomotive acts on distributed capacitance and inductance in TN,those may cause harmonic resonance problems.Harmonic resonance may cause high voltage on locomotives,causing not only damage to equipment and other problems,but also unnecessary economic losses.Electric locomotives are very likely to produce a higher total distortion rate of harmonic voltages.Focusing on the problems of harmonic resonance caused by complex TN and its suppression scheme,the following work is carried out in this paper:(1)According to Carson theory,Principle of Mirror Image and TN topology,establishing a mathematical model of the TN by impedance matrix reduction method.Then draw the Π-type equivalent circuit of complex TNs such as single track,double track,railway station,and regular line with station,and write the node admittance matrix,which lays the foundation for subsequent research.(2)Establish double track Simulink simulation model by multi-conductor transmission theory,and compared with the mathematical model.Use modal analysis method to analyze the high-order harmonic resonance of the complex TN.Study the effects of line length,number of strands,station yards,and locomotives on the high-order harmonic resonance of the complex TN.Research shows that if the number of lines increases or the line length increases,the resonance frequency of TN will decrease.The location of the station in the section will also affect the resonance frequency.Whether the locomotive is located at the station yard or not,the impact on the resonance is small.(3)According to the wiring diagram and power supply schematic diagram of a actual line,establish a mathematical analysis model of complex TN,then compare analysis result with measured data.Analyze the cause of serious harmonic resonance of TS,and the analysis result of the mathematical model is basically consistent with the measured data.The result shows that the complex high-order harmonic resonance band is caused by multiple complex feeders.(4)Consider high harmonic resonance suppression schemes by changing the TPSS parameters or installing filters.Article shows that changing the parameters of the traction network is difficult for existing lines.For the actual line,two schemes of APF+wave-trap high-pass filter and single tuning +wave-trap high-pass filter are researched.Simulation and calculation results show that both can better suppress high-order harmonic resonance and are suitable for AC-DC and AC-DC-AC mixed lines,the filter scheme of the 3rd-order tuned filter + blocking wave high-pass filter works well.It includes the mathematical modeling of complex TN,the analysis of harmonic resonance and the research of harmonic control scheme.The mathematical model analysis and the measured data are compared with each other,which is is basically consistent with the actual situation,and proposes a high-harmonic control scheme.