Research On Simulation Platform Based On CRH3 EMU Auxiliary Power Supply System

The technical level of the railway affects the economic level of the country to a large extent.The railway technology is a collection of technologies for all aspects,and the technical requirements for the auxiliary power supply system of the EMU are also improved accordingly.In the face of the growing auxiliary power supply technology,low breakthrough and less innovation have become the main reasons restricting the development of auxiliary power supply systems,and there are deficiencies such as topology optimization and under-optimization of control strategies.The continuous upgrading of control methods is the focus of research in recent years,and high-disturbance converter technology can adapt to the rapid development of railway technology.Optimizing the auxiliary inverter technology in the auxiliary power supply system is one of the key points of railway technology,so the research in this paper has good practical significance.In the process of investigating the existing technology,it is found that the auxiliary inverter has distortion of the output waveform of the inverter due to the inconsistency of the device parameters and the influence of the load.The general strategy for controlling the output waveform of the inverter is to use the symmetrical component method.The dq-axis component is decomposed in positive and negative sequence,the control is more complicated,or the PI and the repeated composite control strategy have limited control effects.This paper aims to design and upgrade the inverter control strategy,adopting the better performance of the PI and the repetitive composite control strategy after adding the resonant control,and optimizing the converter design.At the same time,the experiment is carried out to verify the superiority of the control strategy.In this paper,the auxiliary power supply system of various EMU models is investigated firstly,and the existing auxiliary power supply system structure is analyzed.Then,for the auxiliary inverter,the CRH3 type vehicle is taken as an example to establish the auxiliary power supply system model,and the three-phase auxiliary inverter is studied.The device is based on the double-loop decoupling control of the output voltage current feedforward.The paper focuses on the modeling and analysis of three-phase inverters.From the perspective of device efficiency and digital control,SVPWM control is considered.In order to deal with the upgrade of auxiliary power supply system and load diversity,and considering the unbalanced voltage,the paper analyzes PI and repeats separately.The composite unbalanced voltage control strategy and the PI and repeated composite control strategies added to the resonant controller are used to simulate the experiment to verify the superiority of the improved composite control strategy.The paper also builds other sub-models of the auxiliary power supply system,including:three-phase Models for filters,battery chargers and on-board single-phase inverters.Finally,the whole auxiliary power supply system model is built and simulated in MATLAB/Simulink environment to verify the feasibility of the whole simulation system.At the same time,for the package storage and easy to use of each module,the auxiliary power supply system simulation demonstration platform is designed.It has certain practicability and reference for practical application in the future.