Research On Operation Characteristics And Control Optimization Of Traction Drive System Of Multi-system Electric Locomotive

In recent years,in order to meet the needs of economic and social development for transportation in China,the electrified railway technology has been developed rapidly.According to the requirements of the National Railways' 13 th Five-Year Plan: The railway construction in China needs developed to be a network and connecting cities and regions by intercity railways,mainline railways and high-speed railways;With the development of various city circles,comprehensive and efficient construction of China's urban rail transit network is required;the “One Belt and One Way” strategy puts forward that China's railway construction not only meet the basic requirements of domestic rail transportation,but also need to connect with the railway networks of other countries in the world.In summary,the research on Multi-system Electric locomotive(MSEL)that can be compatible with different power supply systems is the inevitable way for China,to connect with electrified railways in other parts of the world and improve the competitiveness of Chinese locomotive enterprises.This dissertation is based on the National Natural Science Foundation of China project "Research on the Multi-used technology of apparatus of multisystem electrical locomotive and its transient characteristics when switching the power supply system(No.51477044)",and with the funding and support provided by the project of CRRC DATONG Co.,Ltd.and CRRC Zhuzhou Electric Co.,Ltd.,a comprehensive exploration and research on the operating characteristics of the MSEL traction drive system(TDS)has been carried out.On this basis,a more in-depth study was carried out on the harmonic resonance and stability problems of MSEL-TDS running in different power supply systems,and corresponding optimized control strategies were proposed.The main research work completed in this dissertation includes:(1)Analyzed the topological structure,equipment reuse scheme,and converter control method of MSEL-TDS under different power supply systems,and established a simulation model of typical MSEL-TDS;The operating characteristics of MSEL-TDS are simulated and analyzed in AC power supply system,DC power supply system and the switching process of the power supply system,to verify the effectiveness of the established MSEL-TDS model parameters and control methods,and laid the foundation for the follow-up MSEL-TDS optimization control research.(2)The LCL filter is used to replace the traditional L filter,which can effectively suppresses the high-order harmonic current injected into the AC traction network when the MSEL is operating under the AC power supply system,and improves the harmonic characteristics of the locomotive load.However,considering the limited installation space of locomotive equipment,based on the non-orthogonal decoupling theory,a technical solution of integrated filter reactors traction transformer(IFRTT)is proposed.The filter inductors is integrated into the traction transformer to reduce the space occupied by the filter equipment.The electromagnetic characteristics of the IFRTT are theoretically analyzed,a prototype of the IFRTT is designed and built,and the corresponding ANSYS finite element model(FEM)is built.The simulation verifies the decoupled characteristics of the integrated filter inductors winding and other windings of the transformer;Combined with the low-power prototype of the IFRTT,an experimental study on the filter characteristics of the LCL converter was carried out,and the effectiveness of the IFRTT was verified.(3)A passive decoupling control(PBC)method for single-phase LCL converters based on Euler-Lagrange(EL)equations is proposed.The detail passive decoupling controller of single-phase LCL type converter is studied and designed.In order to verify the feasibility of the proposed PBC based single-phase LCL grid-side converter,a simulation model based on Matlab/Simulink and Star-sim semi-physical real-time simulation platform was established,and the comparison is implement by traditional d-q decoupling proportional-integral(PI)controller based and the passive decoupling controller based single-phase LCL converter system,simulation and semi-physical real-time simulation results verify that the passive control method can track the given signal quickly and without static error,and has good harmonic performance,dynamic and static performance and robustness.(4)The stability of the MSEL cascade traction drive system composed of LC filter,DC/DC converter,traction motor under DC power supply system is studied.The output and input impedance characteristics of each component of the cascade traction drive system Are deduced,and the stability of the cascade traction system composed of LC filter-DC/DC converter-inverter motor is analyzed by the impedance ratio criterion method.A DC/DC converter control method with virtual capacitor and output current feedforward is proposed to improve the dynamic performance and stability of the cascaded traction drive system under the DC power supply system.Finally,the effectiveness and feasibility of the proposed control method are verified by simulation and semi-physical real-time simulation..(5)A deadbeat predictive current control method is proposed to eliminate the control delay caused by the sampling and PWM modulation of the micro-controller.In order to reduce the influence of disturbances such as changes in traction motor model parameters on the stability of the deadbeat predictive current controller,a delay control method is adopted to perform feedforward compensation for disturbances.Finally,simulation and semi-physical real-time simulation verify that the improved deadbeat predictive current control method can improve the control performance and robustness of the traction motor system.