Articles

Design and build an Arduino-Based Inverse Time and Constant Time Overcurrent Protection Relay

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This study discusses the design and implementation of a overcurrent protection system using two types of relays, namely Inverse Time Overcurrent Relays and Constant Time Overcurrent Relays based on Arduino Uno microcontrollers. The system is designed to detect and respond to overcurrent disturbances that occur at resistor loads using current sensors, relay modules, and LCD displays. In an inverse time system, the disconnection time depends on the magnitude of the interference current, where the larger the current, the faster the relay works. On the other hand, in a constant time system, the relay will cut off the current at a predetermined time, regardless of the size of the current. The Arduino Uno acts as a controller brain that processes data from the current sensor and determines the disconnection logic. The test was carried out to evaluate the relay working time characteristics of the interference current variation as well as the effect of the multiplier factor value on the disconnection speed. In addition, the system is also equipped with a PZEM-004T CT module for real-time monitoring of electrical parameters and a 16 2 LCD display as a user interface. The test results show that the system is able to work effectively according to the characteristics of each type of relay. This prototype offers a practical and economical solution in the simulation of electrical protection systems, particularly in microcontroller-based learning and development environments.​

Design and Construction of the Standard Inverse and Constant Time Overcurrent Relay Simulator Based on Arduino

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Overcurrent relay as one of the protection systems in the electricity distribution network has been improved in performance through the implementation of microcontrollers. To simulate the work of overcurrent relays, an Arduino module based on Atmega328P can be used to study the working algorithm of overcurrent relays. This research aims to design and build  an Arduino-based overcurrent relay simulator  with two working time characteristics, namely standard inverse and constant time. The simulator is equipped with a CT-based current sensor and a PZEM-004T module to read the current, as well as using a 20×4 I2C LCD and  a 4×4 Keypad as the user interface. Once the simulator is designed, the next step is testing to measure the accuracy of the sensor readings and the performance of the relay at various variations of current and timing settings. The test is performed at a voltage of 220 Volt Alternating Current (AC) and at a variety of current variations i.e., 0.5 A, 1 A and 1.5 A currents.  The test results showed that the system was able to work according to the characteristics of standard inverse and constant time with an average  error of measurement of the relay working time  of less than 2% for standard inverse and 0% for constant time. This proves that this Arduino-based overcurrent protection system is accurate and responsive.