Research On Harmonic Mechanism And Suppression Strategy For XiSi Traction Power Supply Section Of Harbin-Dalian High Speed Railway

In recent years,with the rapid development of high-speed railway in the world,China's high-speed railway technology has gradually reached front ranking of the world and the demand for power quality of traction power supply system is also increasing.The traction network of Harbin-Dalian high speed railway is mainly affected by the higher harmonics which result in many accidents,such as low frequency of traction voltage oscillations,traction substation capacitor bulge,traction transformer abnormal sound,lightning arrester breakdown and so on.Therefore,the power supply section of XiSi traction and the CRH380 BG EMU are treated as research objects in the paper,then the simulation model of the combined system of those two research objects is established.Also,the paper analyzes the harmonic distribution of the traction network in the typical operating conditions of the EMU,and uses U902 power quality monito to measure and evaluate the harmonics of the power supply section.Last but not least,the paper proposes specific measures for improvement aiming at problems of the higher harmonics pollution in the XiSi power supply section.Firstly,this paper analyzes the all-parallel AT power supply method adopted in the XiSi traction power supply section of Harbin-Dalian high speed railway,and combines the multi-conductor transmission line theory and Carson theory to establish the traction network ? type equivalent model.Meanwhile,the traction network is naturally cut through the horizontal parallel element and the locomotive position,and make the multiple transmission lines of traction network equal to 10 wires and establish a chain network model.Additionally,combined with the actual situation of the traction network,the traction network parameters are calculated and then a simulation model of traction network is built with Matlab/Simulink.The simulation results are consistent with the power supply principle of AT,which shows the correctness of the system model.Secondly,according to the structure characteristics,working principle and harmonic generation mechanism of CRH380 BG EMU traction drive system,this paper builds the EMU traction drive system simulation model.The simulation results show the network side harmonic current of EMU under different working conditions,which is consistent with theoretical analysis.Thirdly,based on the above models,the joint model of the traction network and the CRH380 BG EMU is carried out.Besides,harmonic distribution of the traction network simulation analysis is made when the model is simulated under different working conditions.Moreover,by making use of U902 power quality monitor,the power quality of the XiSi traction power supply section is monitored.Actual measurement results verify the correctness of the theoretical analysis and simulation results.Finally,aiming at the problem of high harmonic pollution in XiSi traction power supply section of Harbin-Dalian high speed railway,the second-order high-pass filter,the high-pass filter and active filter are adopted to suppress harmonic.By comparing the effects of the filter in different installation locations and different operating conditions,the high-pass filter suppression scheme is naturally adopted.It provides the theoretical reference for harmonic suppression of the Harbin-Dalian high speed railway traction power supply system.