Microcontroller-Based Real-Time Energy Monitoring and Voltage Protection System using ESP32

Abstract

This research concentrates on the creation of an intelligent energy monitoring and voltage protection system utilizing the ESP32 microcontroller. The system\'s main goal is to help people keep track of how much electricity they use and protect their electrical appliances at the same time. It is common for household electrical systems to have sudden changes in voltage and too much current. Because of this, appliances might not work right and their life span might be shorter. In some cases, it can also make things unsafe. The proposed system keeps an eye on the main electrical quantities, such as voltage, current, power, and total energy used, to deal with this problem. A voltage sensing circuit detects the supply voltage, and a current transformer measures the load current. After being measured, these signals are used for more processing and monitoring. The ESP32 takes these signals and figures out the real-time power usage of the load by calculating the RMS values. The system has a relay mechanism built in to keep it safe. The relay automatically disconnects the load if the voltage or current goes above a certain safe level to protect it. A 16×2 LCD screen shows the measured values and the status of the system, making it easy for the user to see how much energy is being used and how the system is doing overall.

Introduction

Electrical appliances in homes and small shops often face problems such as high voltage, low voltage, and excessive current, which can damage equipment and create safety risks. Traditional energy meters only measure total electricity consumption for billing and do not provide information about voltage conditions or load behavior. As a result, users usually become aware of electrical problems only after appliance damage or an unusually high electricity bill.

To solve this issue, the study proposes a Smart Energy Monitoring and Voltage Protection System based on the ESP32 microcontroller. The system measures AC voltage and load current using sensing components and calculates RMS voltage, RMS current, real-time power, and total energy consumption. These values are displayed on a 16×2 LCD, allowing users to monitor their electricity usage in real time.

The system also includes a relay-based protection mechanism. If the voltage becomes too high, too low, or if the current exceeds a preset limit (overload condition), the ESP32 automatically activates the relay to disconnect the load, protecting appliances from damage.

The design consists of several components such as a step-down transformer, bridge rectifier, voltage regulator, current transformer (CT), ESP32 controller, relay module, and LCD display. The transformer reduces the high AC voltage to a safer level, while the CT sensor measures current without direct electrical contact. The ESP32 processes the signals, calculates electrical parameters, and controls the protection system.

The methodology involves real-time sensing, signal processing, calculation of RMS values, power and energy measurement, and automatic protection logic. The system continuously compares measured values with safety thresholds and controls the relay accordingly.

Testing results show that the system can accurately monitor voltage, current, power, and energy consumption while quickly disconnecting the supply during abnormal conditions such as overvoltage, undervoltage, and overload. Overall, the project provides a low-cost, reliable, and efficient solution for household energy monitoring and electrical protection, improving both energy awareness and appliance safety.

Conclusion

Electrical power is used every day in homes and small shops for running different appliances. In many cases, the supply voltage is not stable and problems like high voltage, low voltage, or excessive current can occur. Because of this, electrical appliances may get damaged or their performance may reduce over time. Sometimes these issues also create safety risks. Normal energy meters only record total energy for billing and do not show detailed information about voltage condition or load behavior. So most users come to know about the problem only after equipment failure or a sudden increase in the electricity bill.

References

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Copyright

Copyright © 2026 Shubham S. Nimbekar, Babali R. Chakole, Ashwini B. Malewar, Samruddhi P. Hinge, Tushar V. Wanjari, Gaurav R. Panchbudhe . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.