Transmission Line Sag Remote Monitoring System Based On Low-Power Wide-Area Network

As the country’s pillar energy and economic lifeline,the power system has extremely high requirements for power grid security.The transmission line is an important part of the power system,and the real-time monitoring of the transmission line is of great significance to the operation and maintenance of the power grid.As of 20 20,the total length of my country’s transmission lines has reached 1.142 million kilometers,and it is still increasing year by year.The power grid needs to accurately monitor the parameters of the power system to ensure the safety of the power grid,and it is inevitable to conduct inspections on the transmission lines.The sag information is one of the important data for the inspection work.At present,the operation and maintenance of transmission lines in the power grid are still mostly completed by manual inspection,which is costly in time and has certain risks in some areas.At present,some monitoring equipment has been put into trial operation in a few areas,but due to the low monitoring performance of the existing monitoring equipment and the dif ficulty of information sharing,there will be problems such as the data cannot reflect the real-time status of the equipment.On this basis,this study proposes a new type of transmission line sag monitoring system.This study adopts LoRa(Long Range)technology and NB-IoT(Narrow Band Internet of Things)technology,both of which are more prominent applications in low-power wide area network technology.There are two nodes in this system,each node includes a high-precision tilt sensor,a power supply and a LoRa module,and LoRa is used for communication between the two nodes.One of the nodes contains the NB-IoT module.The terminal node calculates the sag based on the inclination data measured by the sensor and the mathematical relationship between the inclination and the sag,and stores the data after error correction.The NB-IoT module is used to upload the final sag data to the cloud platform.If the sag data exceeds the preset threshold,an alarm message will be sent,that is,the real-time monitoring function and abnormal alarm function of transmission line sag can be realized.After the simulation test,the sag data accuracy and data transmission stability can meet the needs of sag monitoring.The proposed monitoring scheme has certain research value and significance for the monitoring of transmission line sag parameters.The main tasks of this design are as follows:(1)High-precision sag information acquisition system.There are two nodes in this experiment.The inclination sensors of the nodes are installed at both ends of a high-voltage transmission line to measure the inclination angle at the end of the transmission line.The sag of the transmission line is calculated by using the inclination data monitored by the two points.(2)Stable long-distance communication system.The two nodes in the system communicate point-to-point through LoRa,and the long-distance communication characteristics of LoRa can be used for stable small data transmission between nodes.The sag data is finally sent to the monitoring terminal through the NB-IoT module.This communication method adopts the cellular network,which has a wide coverage and long propagation distance and can be applied only with a simple communication protocol.The communication system composed of the two has strong anti-interference ability and stable operation.(3)Real-time monitoring and alarm functions.After logging in to the cloud platform,configure the communication module on the cloud platform,so that it can display the data uploaded by NB-IoT on the monitoring screen,and can also monitor the sag data in real time through the mobile phone.At the same time,the alarm trigger value can be set for the sag data.When the sag data exceeds the set value,the cloud platform will send an alarm messa ge to the user,and real-time notification via SMS,We Chat and email.(4)Low power design.Both LoRa and NB-IoT communication modules used in this design belong to low-power wide-area network technologies.The module consumes low power and can further reduce power consumption through a reasonable working mode.At the same time,the power supply scheme of solar energy and lithium battery is adopted,so that the system can achieve self-sufficiency outdoors and ensure stable operation for a long time.