Three Phase Induction Motor Protection System by using PIC Microcontroller

This paper include a protection system for 3-phase induction motors from single-phasing, voltage and current variations, speed variations ,over temperature and vibration faults. A model was proposed, which can help to determine the impact of single phasing on any 3-phase induction motor. Due to single phasing fault the winding of motor get heated which lead to insulation failure and hence reduce the life of motor. Due to variation in induction motor parameters the above faults are generate in induction motor. The latter, in additional to protection against single-phasing, also protects the motor from under-voltage, over-voltage and over temperature. In the hardware circuit is completely controlled by the PIC microcontroller (16F877A) and observing the voltages of three phase. Motor will turn off if the voltage goes beyond the rated limit. By use of current transformer which senses the current and if it exceeds rated limit then with the help microcontroller contactor stop the motor. The LCD display shows all the above conditions if any fault occures. In this paper we are utilizing the 8 bit PIC microcontroller (16F877A).