Design Of Wireless Temperature Measurement System For Power Cable Based On LoRa

In recent years,my country’s power industry has developed rapidly,and the increase in electricity demand has also brought about an increase in the rate of electrical safety accidents.Among them,the power cable is the key device for transmitting electric energy.In the continuous working state,overload,line aging,or short circuit may cause insulation breakdown,resulting in a change in the surface temperature of the line.Therefore,the working status of the power equipment can be judged by the surface temperature of the cable.Therefore,this research designed a wireless temperature measurement system for power equipment based on LoRa to monitor the surface temperature of the cable in real time.This paper starts from the actual application of the project,and the overall design plan is determined according to the design requirements.The node hardware portion takes a low-power STM32L0 series single-chip microcomputer,and the thermistor is used to finish the temperature measurement function,and the LORA communication chip is designed with the wireless transmission and receiving circuit,reach a long distance and ultra low power communication.Designed a 433 MHz PCB antenna designed for the design requirements of the temperature measurement node.The antenna is designed with a zigzag structure.By changing the sawing teeth,the spacing,after multiple simulation tests,the final echo loss is less than-16 d B,with a certain gain.The gateway hardware portion is based on the PIC microcomputer,and the communication,storage and other circuit design are completed.System software levels include: data acquisition,wireless communication,communication protocol design,etc.,complete the interface design of monitoring host and Android APP.It mainly implements the following functions: Node data acquisition;node,gateway,and normal communication between the gateway and the monitor host.The monitoring host can display the operating state,binding position,alarm situation,etc.of all current nodes in real time.You can view historical alarm records,you can set the report cycle,temperature difference and heartbeat cycle according to the number of actual access nodes.According to the actual use environment,you can modify the current communication scheme.Because the system is used in the industrial environment,it is necessary to ensure that the system is sufficiently reliable in actual use.Therefore,a large number of tests in terms of system performance,ultimately realize that the system standby power consumption is only 2.0u A,and the communication distance reaches 800 m.Compared with similar products on the market,there is a big increase in system power consumption,transmission power,communication distance,and floor penetration ability.