DEVELOPMENT OF A CURRENT SOURCE FOR PROTECTION RELAY TESTING

Abstract

This work presents the development of a Didactic Panel for Protection Relay Testing, designed to inject high currents for the validation of protection devices. The tool was engineered to supply currents of 20A with continuous adjustment, ensuring stability and safety throughout the operation. The system integrates electrical and electromechanical components that collectively enable precise control of the supplied current, with its power architecture based on a combination of a single-phase Variac and a three-phase autotransformer, which is responsible for providing the necessary current. Fine adjustment of the current injection is performed by a NEMA 17 stepper motor driven by the ESP32 microcontroller, allowing for automated, high-precision adjustments. The final panel features a complete interface for measuring and displaying the trip time, contributing to the improvement of protection relay testing and calibration processes and providing an efficient and safe tool for didactic applications in electrical engineering laboratories