Design and Construction of a Prototype Arduino-Based Fault Detection System for the Agu-Awka 132 KV Transmission Line Using GSM Feedback

High-voltage transmission systems should be reliable, which can influence the stability of power systems and limit interruptions to energy supply. The Agu-Awka Transmission Company of Nigeria (TCN) substation has an installed capacity of 2 × 60 MVA at 132/33 kV that links the Onitsha–Enugu transmission corridor to the Awka distribution network. Frequent faults such as single-line-to-ground, double-line, and three-phase short circuits within this corridor often result in prolonged outages and equipment damage due to delayed fault detection and reporting. This paper presents the design and construction of a prototype Arduino-based fault detection system for the Agu-Awka 132 kV transmission line with GSM feedback. The system is designed using current and voltage sensors interfaced with ATmega328p microcontroller to monitor line parameters continuously. When the system detects an abnormal condition beyond a specified limit, it gives a signal to isolate the affected phase through the relay. SMS is sent to the control room for corrective action. Results demonstrate fast detection, accurate fault phase identification, and reliable GSM feedback transmission. This low-cost, scalable solution provides a foundation for smart fault monitoring in Nigeria’s high-voltage transmission network, enhancing operational reliability and reducing downtime across substations such as Agu-Awka.