IoT-Based Real-Time Monitoring of Transmission Line Critical Parameters During Fault

This paper presents the design and implementation of an IoT-based system for real-time monitoring and fault detection in electrical transmission lines. The proposed solution integrates current transformers (CT), potential transformers (PT), temperature and oil-level sensors with an ATmega328P microcontroller and ESP8266 (NodeMCU) Wi-Fi module. Measured parameters—voltage, current, temperature, and earth leakage—are sampled via the microcontroller’s ADC and multiplexed, then transmitted over TCP/IP to the ThingSpeak cloud platform for dashboard visualization. The system automatically detects over-voltage, under-voltage, short-circuit, open-circuit, and earth-fault conditions, triggering a relay cutoff, LCD display update, and buzzer alert. Laboratory tests confirm accurate fault identification and sub-second response times, demonstrating a low-cost, scalable solution for enhancing grid reliability and reducing maintenance overhead