Internet of Things (IoT)-Based Overvoltage Protection and Monitoring System for Single-Phase Electrical Networks

Voltage quality in single-phase electrical power networks for residential applications does not always remain at nominal conditions and is prone to fluctuations caused by load variations and distribution network conditions. Repeated or sustained overvoltage conditions can reduce equipment lifespan and damage electrical and electronic devices. Therefore, this study aims to design and implement an overvoltage protection and monitoring system for single-phase power networks based on the Internet of Things (IoT). The proposed system employs a PZEM-004T 10A module for electrical parameter measurement, an ESP32 microcontroller as the main controller, and a Solid State Relay (SSR) as the protection actuator. The system is designed to detect overvoltage conditions, automatically disconnect and reconnect the load based on predefined voltage thresholds and time delays, and provide real-time monitoring through the ThingSpeak IoT platform. Experimental results indicate that the measured line voltage ranged from approximately 196 V to 235 V, with an average value of about 203 V. The maximum recorded current was 2.48 A with a maximum active power of approximately 466 W, while the system frequency remained stable around 50 Hz. The measured power factor varied between 0.27 and nearly 1.0. The protection mechanism operated reliably without significant false trips, and the IoT-based monitoring system successfully logged and visualized real-time data. These results demonstrate that the developed system is effective as an IoT-based solution for overvoltage protection and monitoring in single-phase electrical power networks.