Design And Implementation Of Modular Input And Output Module Of HXB 3B Electric Locomotive

With the rapid development of my country’s industrialization and national economy,the quantity and speed of cargo transportation are showing a trend of rapid increase.Compared with other modes of transportation,railway transportation has the advantages of large carrying capacity,low energy consumption,low emissions,and low pollution.The main means of railway transportation is the Harmony high-power electric locomotive.As a representative of the high-power electric locomotive,the HXD 3B electric locomotive has become the main means of transportation of goods in my country.The power system of the HXD 3B electric locomotive is mainly divided into two parts: the main circuit system and the control system.The control system is based on the microcomputer network control system.In the microcomputer network control system,the digital input and output modules are used for high-voltage electrical cabinets,auxiliary power distribution cabinets,low-voltage power cabinets and auxiliary filter cabinets and other equipment operating status detection to ensure the safe operation of the entire microcomputer network control system,which is the entire control system Core part.At present,the digital input and output modules in the micro network control system of the Harmony 3B electric locomotive have shortcomings such as few real-time transmission channels,poor module protection mechanism,narrow voltage working range,lack of research and development in domestic enterprises,etc.,which cannot meet the needs of domestic electric locomotives.Actual operational requirements.Therefore,based on the multifunctional vehicle bus technology and field programmable logic gate array programming technology,this article designs a digital input and output module for the HXD 3B electric locomotive.This module can not only realize digital multi-channel and real-time information transmission,effectively increase the information transmission speed of the module,and improve the working performance of the module,but also it can realize a more complete protection mechanism and improve the safety performance of the module.Based on the analysis and study of the current situation of digital input and output modules at local and overseas,in terms of hardware,according to the digital input and output standards of the computer network control system of the HXD series of electric locomotives,the design parameters of the digital parameters of the module are determined,and the design parameters of the module are determined according to advantages of the hardware circuit modularization,and the design the control unit and digital input/output unit of the module,and use MVB bus protocol specification and FPGA technology to design the hardware circuit of the control unit and digital input/output unit.According to the safety indicators of the microcomputer network control system,design and implement the protection circuit of the MIO module,including the over-voltage protection circuit,the power supply protection circuit and the over-temperature protection circuit;use FPGA’s programmability and base address selection to realize the function of self-setting module base address;The photoelectric coupling isolator is used to realize the effective isolation function of the control signal and the input and output signals;the real-time control function of the digital input and output channels is realized by using the feedback closed-loop control principle of the control system.In terms of program design,using Verilog HDL hardware description language,adopting the top-down modular design idea,designed eight working mode programs of the module,and designed digital input and output programs based on the MVB bus protocol,which can be combined with software and hardware.Realize the function of module digital multi-channel real-time transmission.Finally,the module is designed and manufactured in kind and the experimental test of the module is completed,and the functional test of the module is completed.The experimental test results of the module show that the digital input and output module meets the expected design requirements.It not only realizes the function of real-time transmission of multi-channel data,but also has a complete protection circuit,which improves the safety performance of the module.This subject has a huge impetus to the development of the microcomputer network control system for electric locomotives.