Railway Alternating Current Filament Relay On-line Detection System

The alternating current(AC)relay is an important electrical equipment to ensure the normal operation of color lamp signal machine.Ensure the uninterrupted operation of the signal machine.The relay works outdoors with low temperature and high humidity all year round,and the switching performance degrades with the increase of use times.According to the relevant provisions of the Railway Technical Management Regulations,the railway department needs to overhaul the relays inside the lighting unit once every months.At present,the main detection method is that workers remove the relay and send it to the detection department for detection.There are many problems such as complicated operation,long detection cycle and human interference.According to this reality,this topic combined with embedded system and Internet of things technology,designed a set of railway color light signal ac filament relay time parameter online detection system.The system has the characteristics of high integration,fast detection speed,simple equipment deployment and easy operation.Set data acquisition,remote control,wireless transmission,data processing,detection and alarm functions in one.In this paper,the dynamic analysis of JZSJC relay with high utilization rate in railway department is carried out,and the time parameter extraction method of difference method is proposed combining with traditional theory.The system is designed from two aspects of terminal acquisition equipment and cloud platform.The terminal acquisition equipment mainly includes three parts: main control unit,data acquisition unit and information transmission unit.The main control unit selects STM32F407ZET6 as the system main control chip.In the data acquisition unit,BME280 environment chip is used to collect the temperature,humidity and atmospheric pressure around the equipment.The current transmitter and AD7606analog-to-digital conversion chipset are combined into a parameter acquisition device to collect the required relay detection parameters.The ISO3088 photoelectric coupling isolated RS485 chip is used as the information transmission unit controller.The RS485 communication mode is used for bidirectional connection with4G/GPRS-DTU devices that so as to realize the remote terminal server control and data collection report.Through hardware circuit schematic design and PCB layout and drawing,manufacturing terminal acquisition equipment.The cloud platform is written in C# language and developed by using API interface.The cloud platform is written in C# language and developed by using API interface.It mainly includes the functions of remote control relay switching,collection data storage and display,slave device management and so on.Terminal acquisition device and cloud platform rely on a certain type of 4G/GPRS-DTU device,through Modbus-RTU protocol model data transparent transmission.Finally,through data acquisition and verification of each module of terminal acquisition equipment,the paper connects the cloud platform to test the integrity of the railway AC filament relay online detection system.The experimental results show that the system is stable and reliable,and can meet the needs of practical use.