Tag Archive for: Inverse Definite Minimum Time

An overcurrent protection relay is an essential component in electrical system to protect devices from damage due to excessive current. The Inverse Definite Minimum Time (IDMT) type has a trip time that depends on the magnitude of the overcurrent, with faster trip times for higher overcurrent levels. Arduino Uno can be used as a microcontroller platform to build an IDMT with relatively low cost and ease of implementation. This research aims to design and construct an Arduino Uno-based IDMT. The system consists of a current sensor, Arduino Uno, and a relay. The current sensor is used to detect the current flowing through the load. The Arduino Uno processes the data from the current sensor and determines if the current exceeds a predefined limit. If the current exceeds the limit, the Arduino Uno will activate the relay to cut off the current flow to the load. The IDMT trip time is implemented using an algorithm that considers the magnitude of the overcurrent and the minimum trip time. The system is tested using a simulator and actual load. Test results show that the Arduino Uno-based IDMT system works well and can protect the load from damage due to overcurrent.