Simulation Research On Auxiliary Power Supply System Of Medium And Low Speed Maglev Train

With the rapid development of rail transit in China,urban traffic congestion has gradually become an important factor restricting the process of urbanization in China.With the advantages of stability and comfort,low energy consumption and no pollution,medium and low-speed maglev train has become an effective supplement to traditional rail transit and plays a decisive role in the interconnection between urban areas.The auxiliary power supply system mainly supplies power for three-phase loads such as train ventilation unit and air compressor,which has a great impact on the safety and stability of train operation.However,there are still relatively few studies on the auxiliary power supply system of medium and low speed maglev trains in China,and there is also a lack of auxiliary software for rapid simulation design of the auxiliary power supply system of maglev trains.Therefore,based on the auxiliary power supply system of Qingyuan medium and low speed maglev train,this paper conducts an overall simulation study on its key control technology.The modular idea is introduced to establish the overall simulation platform of train auxiliary power supply system,and the software page is designed to facilitate the subsequent verification and development of new models by vehicle manufacturers.Firstly,this paper clarifies the overall structure and power supply mode of the auxiliary power supply system of Qingyuan medium and low speed maglev train,and establishes the overall framework of the auxiliary power supply system.Then,the working characteristics of the main single components of the auxiliary power supply system are studied,and the auxiliary converter,charger and suspension power supply are analyzed from the aspects of topology structure and working principle.Divide the main structure of the auxiliary converter,analyze the working principle of the front-stage DC/DC converter of the auxiliary converter,establish the mathematical model of the back-stage DC/AC inverter,and design the LC filter parameters that meet the working requirements of the system;The working principle of charger is analyzed,the small-signal model of phase-shifting full bridge DC/DC converter is established,and the parameters of charger are designed at the same time;the suspended power supply model is simplified and the system model block diagram of its single module is established.The analysis of the main single components of the auxiliary power supply system lays a theoretical foundation for the design of the subsequent control scheme.Secondly,this paper designs the control system of the core components of the auxiliary power supply system.In order to solve the problem of balanced operation of each module in the ISOP structure of the auxiliary converter and improve the stability of the converter,three loop control strategy and double closed-loop decoupling SVPWM control strategy are designed;In order to improve the accuracy and stability of battery charging,the charging control strategy of constant current and constant voltage is designed,and the fuzzy controller is introduced to optimize the charging process;In order to solve the problem of uneven power distribution of parallel modules,the principle of circulating current in parallel system is analyzed,and the droop control strategy is introduced to improve the current sharing characteristics of the system.Finally,this paper establishes the overall simulation model and software page of the auxiliary power supply system of medium and low-speed maglev train.According to the actual operating conditions of the train,the output of the auxiliary power supply system under various working conditions of the train is simulated and analyzed,and then the real vehicle test is carried out on the auxiliary power supply system experimental platform of medium and low-speed maglev train.The measured data are compared with the simulation data to further verify the feasibility of the overall model of the auxiliary power supply system.Based on the overall simulation model of the auxiliary power supply system.The software page of auxiliary power supply system of medium and low speed maglev train is designed,which provides a reference for the design and maintenance of subsequent new models.