An IoT-based Sag Monitoring System for Overhead Transmission Lines

This study aims to monitor the sag of an overhead transmission line by proposing an IoT-based sag monitoring system, which can provide real-time sag information of a transmission line, preventing ground fault using an embedded three-axis accelerometer with IoT techniques. This reliable monitoring system directly measures sag-related parameters on and around a high voltage transmission line in real time. The measured results are highly similar with theoretical values. Moreover, the accuracy of the measured sag values has been verified by comparing the values with field measurements. These results confirm the high accuracy, reliability and durability of the proposed sag monitoring system. In addition, this study examines the measurement results obtained from the devices placed on the three phases of a transmission line to verify the feasibility of applying IoT techniques to high voltage transmission systems. The results show that this proposed sag monitoring system has overcome the challenge brought by the strong electromagnetic field surrounding a transmission line with high voltage. By adopting IoT techniques, the proposed system is able to be widely implemented on large-scale power grid systems.