A Novel High-Voltage Transmission Line Joint Temperature Monitoring System Using Hybrid Communication Networks

Line joint temperature monitoring is used in high-voltage transmission lines to improve the reliability and safety of power lines. However, traditional monitoring methods (e.g., manual inspection, UAV inspection, short-range wireless technology, etc.) cannot realize real-time monitoring of line joint temperature in remote areas. In this paper, we proposed a novel real-time monitoring system, which adopted a communication method combining ZigBee and LPWAN technology (LoRa and NB-IoT) for long-distance transmission. In this system, each power tower was regarded as a communication node that contained a main node and multiple subnodes. First, each node collected temperature data of the transmission line junctions by ZigBee and microprocessor processed and analyzed the data. Second, the LoRa multihop communication technology was used for transmission of the data between adjacent nodes to achieve wider coverage and a longer transmission distance. Finally, the end of the network was a main node, i.e., an LoRa-NB-IoT gateway. The temperature data of all nodes were transmitted to the “USR Cloud” by the NB-IoT technology. By conducting a system test, the system can meet the requirements of long-distance communication outside and reduce power consumption. After calculation, the system communication packet loss rate is approximately 3.3%, and the average power consumption of the system is about 21.19 mA. The PC can monitor the transmission line junction temperature in real time, transmission is stable, and the alarm function can be also realized. Therefore, the system is more suitable for temperature monitoring of line junctions in remote areas, achieving long-distance data acquisition and transmission through low power consumption and high transmission rate.