The Research On The Impact Of Dc-link Voltage Pulse On The Network Side And Motor Side In Electric Traction Inverter

Traction converter is one of the main components of electric traction drive system,the important guarantee of the train power system normal work and safe operation.However,because of the high speed train commonly used single-phase pulse rectifier at the network side of the traction converter.Dc-link exists pulse current under the double traction network frequency.The traditional measure is LC resonant filter circuit in series with the dc link to absorb secondary current ripple,but in recent years,with Chinese high-speed rail technology progress and the pursuit of high speed and lightweight for trains,the part CRH of the independent research and development all cancelled the quadratic absorbing circuit in dc side of traction converters.But when the traction converters of no quadratic absorbing circuit are at work,current pulse in the intermediate Dc-link is bound to cause the voltage fluctuation of two times frequency of traction network.Based on this background,the paper regarding the electric traction converters of no quadratic absorbing circuit as the research object,firstly studies the reasons of the traction inverter Dc-link voltage pulse,respectively analyses the influence of Dc side voltage pulse on converters network side rectifier system and traction inverter motor system.Then,based on summarized the influence law of Dc voltage pulse on the network side rectifier system,the paper studies the network side current low harmonic suppression algorithm in discrete domain,using the low pass filter,or the proportions repetitive controller,or the proportions resonant controller,and according to the features of four quadrant pulse rectifier current loop discusses three kinds of controller parameters selection;based on summarized the influence law of dc voltage pulse on traction inverter and motor system,this article studies the three-phase single cycle pulse width modulation algorithm from the perspective of modulation algorithm,and the motor frequency compensation algorithm from the perspective of the rotor field-oriented vector control strategy of direct respectively.Finally,this article uses Matlab/Simulink software to complete building the simulation model for network side rectifier system and traction inverter motor system,and designs the detailed simulation scheme and verify the theoretical analysis for Dc voltage ripple producing reasons,effects,and suppression algorithm of according to the specific object respectively.By observing the simulation results.the analysis and comparison of the data,verify the validity of the theoretical analysis,to determine the optimal scheme of network side current low harmonic suppression algorithm,and investigated effectiveness of two kinds of beat frequency current suppression algorithms in this paper.