Design and Development of a Single-Phase Electrical Protection System with Fault Identification Using Current and Voltage Detection Methods

Abstract

Electrical faults such as Over Voltage, Under Voltage, Overload, and Short Circuit can reduce the safety and reliability of low-voltage single-phase electrical systems. This study develops a prototype protection system that detects, identifies, and records fault conditions using current and voltage parameters. The system uses an Arduino Mega 2560 with PZEM-004T, ACS712, SCT-013-030, and ZMPT101B sensors, a Solid State Relay (SSR) for load disconnection, a 4x4 keypad for threshold setting, an LCD for status display, and RTC-Micro SD data logging in CSV format. The prototype was evaluated under normal operation and four fault conditions. Short Circuit identification combines Current Ratio and Voltage Sag with thresholds of ≥2.0x and ≥25% respectively, and an 80 ms Definite Time. The test results show that the SSR remains ON under normal conditions and successfully disconnects the load when faults are detected. In the short-circuit simulation using 220 Ω, 100 Ω, 68 Ω, and 47 Ω fault resistances, the system produced the status "TRIP SC-DEF.TIME" for all tested events. Sensor response testing selected SCT-013 as the main current sensor and ZMPT101B as the main voltage sensor, while ACS712 and PZEM-004T support validation, monitoring, and logging. The main novelty is local fault-type identification on the LCD combined with fault-history data logging.