高速电力动车组是铁路高新技术的载体。电力动车组的牵引交流传动是高速动车

High-speed electric multiple units are the carrier of high-tech railway. The traction AC drive of the EMU is an important component of the nine key technologies of the high-speed EMU. The three-level traction converter system designed and studied in this subject is a core component of the high-speed EMU traction AC drive system. From the perspective of its basic structure, the three-level EMU traction converter system is actually an AC-DC-AC converter system. The working principle of the AC-DC-AC traction converter system is as follows: the single-phase alternating current obtained from the catenary is stepped down by the traction transformer and input into the traction converter, which is converted into a DC voltage by its internal rectifier and stabilized by the DC loop Ground input inverter, converted into three-phase AC power and then output, to provide energy for the traction motor. <br>In view of the important position of electric traction drive technology in the field of EMUs, it is of great significance to conduct research on the related theories and technologies of traction converters of EMUs. <br>After describing the research status of the subject, this paper makes a detailed analysis of the basic structure and working principle of the three-level traction converter system of the EMU. At the same time, in order to improve the overall operation quality of the traction converter, this paper has conducted a more in-depth study on the two important control methods of the single-phase four-quadrant converter, namely the transient current control method and the SPWM method. <br>Taking the high-level EMU three-level traction converter system as the main research object of this paper, the MATLAB/Simulink simulation software platform was used to establish relevant simulation models for simulation experiments. In order to achieve the purpose of learning and mastering the relevant technology of the three-level traction converter system of the EMU and verifying the correctness of its control method through experiments, the simulation model of the single-phase bridge fully controlled rectifier circuit and the three-phase bridge fully controlled rectifier circuit Models, three-level inverter simulation models, etc. were studied separately, and provided simulation results for reference.

高速电力动车组是铁路高新技术的载体。电力动车组的牵引交流传动是高速动车组九大关键技术的重要组成成分。本课题所设计和研究的动车组三电平牵引变流器系统，是高速动车组牵引交流传动系统的一个核心组成部分。从其基本结构来看，动车组三电平牵引变流器系统实际上是一个交—直—交变流器系统。交—直—交牵引变流器系统的工作原理如下：从接触网获得的单相交流电通过牵引变压器降压后输入牵引变流器，经其内部的整流器转换成直流电压，在通过直流回路稳定地输入逆变器，转换为三相交流电然后输出，为牵引电机供能。<br>鉴于电力牵引传动技术在动车组领域的重要地位，对动车组牵引变流器相关理论及技术开展研究具有重要的意义。<br>本文在描述了课题的研究现状后，针对动车组三电平牵引变流系统的基本结构及工作原理进行了比较详细的分析。同时为了改善牵引变流器整体上的运行品质，本文对单相四象限变流器的两种重要的控制方法，即瞬态电流控制方法和SPWM方法，进行了比较深入的研究。<br>以高速动车组三电平牵引变流器系统为本文的主要研究对象，利用MATLAB/Simulink仿真软件平台，为其建立了相关仿真模型进行仿真实验研究。为了达到学习掌握动车组三电平牵引变流器系统相关技术，以及通过实验验证其控制方法的正确性的目的，对单相桥式全控整流电路仿真模型、三相桥式全控整流电路模型、三电平逆变器仿真模型等分别进行了仿真实验研究，并提供了可供参考的仿真结果。

High speed EMU is the carrier of high-tech railway. The traction AC drive of EMU is an important component of nine key technologies of EMU. The three-level traction converter system of EMU designed and researched in this paper is a core part of the high-speed EMU traction AC drive system. From its basic structure, EMU three-level traction converter system is actually an AC-DC-AC converter system. The working principle of AC-DC-AC traction converter system is as follows: the single-phase alternating current obtained from the catenary is input into the traction converter after being depressurized by the traction transformer, converted into DC voltage by the internal rectifier, stably input the inverter through the DC circuit, converted into three-phase alternating current and then output, to supply energy for the traction motor.<br>In view of the important position of electric traction drive technology in the field of EMU, it is of great significance to study the theory and technology of EMU traction converter.<br>After describing the research status of the subject, this paper analyzes the basic structure and working principle of three-level traction converter system of EMU in detail. At the same time, in order to improve the overall operation quality of the traction converter, two important control methods of single-phase four quadrant converter, namely the transient current control method and SPWM method, are studied in depth.<br>Taking the three-level traction converter system of high-speed EMU as the main research object of this paper, using Matlab / Simulink simulation software platform, the relevant simulation model is established for the simulation experiment. In order to learn and master the related technology of three-level traction converter system of EMU, and to verify the correctness of its control method through experiments, the simulation experiments of single-phase bridge full control rectifier circuit model, three-phase bridge full control rectifier circuit model, three-level inverter simulation model are carried out, and the simulation results are provided for reference.<br>