The main intention of this project is to design a microcontroller based system that can be used in power transformer protection. The system checks the operating parameters of the transformer i.e. current and reports the quantity that is flowing through the transformer. The system is designed such that it is able to detect currents above the normal operating level and isolate the power transformer from the distribution line. This isolation process is to ensure that the transformer is safe from any excess current levels that can make it to overheat thus get damaged. It gives a solution to the need to reduce cost of maintenance and ensure that supply of electricity to consumers is not interrupted for long periods taken while repairing or replacing destroyed transformers.

A current sensor ACS712x series has been used in this project as the interfacing instrument between the power transformer and the PIC16F690 microcontroller. The PIC16F690 controls all operations that the device does. A relay and a contactor have been used as the switching gears to isolate the transformer from the power system in case a fault occurs. A monochrome LCD has been used to show system current readings and indicate cases of over-current fault. To warn an operator of a fault occurrence, LEDs and a piezoelectric buzzer have been used. All these peripheral devices depend on the microcontroller to make them operate or otherwise. Some of the tools used in this project include MPLAB – programming software used to write the program for the microcontroller used in this project. Proteus- simulation software has also been used to test whether the design works appropriately before its implementation on hardware. Pickit3- has been used to load program into the microcontroller using MPLAB.