Design Of A Small Traction And Braking Test Device For Metro Train

In recent years,the city rail transit system,for example subway,in China has been rapid development.As the transportation equipment in subway system,the metro train is one of the most important components.Therefore,an experimental system of metro train operation is playing an irreplaceable role in scientific experiments and teaching demonstration.In this paper,a new type of test bench is designed to simulate the traction and brake performances of metro trains,which can simulate the process of starting,acceleration and braking.It takes the computer as the core of the system,and through LabVIEW software and data acquisition equipment to achieve human-computer interaction.The friendly man-machine interface and the allow landing system function are designed,and two kinds of operation modes are provided to demonstrate the operation of the test bench.One is through the LabVIEW virtual instrument technology to achieve the simulation of the driver controller,another is directly through the physical driver controller to operate the test bench.The control system can be divided into three parts:traction control system,brake control system and data acquisition system.Traction control system is mainly composed of frequency converter,three-phase AC motor and brake disc;Brake control system is mainly composed of a programmable power supply,a DC electric push rod and a braking clamp device;Data acquisition system is composed of data acquisition card,Holzer sensor and pressure sensor.The control system is built under the LabVIEW software,and the driver controller signal and sensor signal are collected by data acquisition card.After analyzing and processing the signal in the LabVIEW software,the control instructions are sent to the actuator through the data acquisition card and serial port.After receiving the control command,the inverter controls the traction process of the three-phase AC motor,the programmable power supply controls the brake process of the DC electric push rod.The actual operation condition of the test bench is returned by the sensors to the computer to realize the condition monitoring of the test bench.At last,the test bench of the traction and braking performance of the metro train is tested under the laboratory conditions.The test results show that the test bench meets the design requirements and achieves the purpose of the development of the project.