IoT-Based Overcurrent Protection in Substations: A Case Study of New Enma Substation, Aden

The increasing integration of Internet of Things (IoT) technologies into modern power systems has introduced new possibilities for flexible, scalable, and intelligent protection schemes. This paper presents the design and implementation of an IoT-Based overcurrent protection system that emulates the functional behavior of numerical protection relays while leveraging software-based processing and industrial communication technologies. The proposed scheme implements ANSI 50/51 overcurrent protection functions using the Node-RED platform combined with industrial IoT edge devices for real-time data acquisition and control. The protection architecture follows a layered IoT framework, starting from field-level current measurements, through edge data acquisition and communication layers, to software-based protection logic execution and circuit breaker actuation. A two-stage overcurrent strategy is employed, comprising a high-set definite-time element and a low-set inverse-time element based on IEC standard characteristics. The proposed system is validated through multiple operating scenarios, demonstrating reliable fault detection, accurate operating times, and secure tripping behavior. The results confirm that IoT-Based software protection can serve as an effective and low-cost complementary or backup solution to conventional protection relays, particularly in developing power networks and smart substation applications.