This three phase induction motor protection system using PIC microcontroller, protects the three phase induction motor during any fault condition such a temperature or voltage variation, in any phase of three phase ac supply. The principle motivation behind our project is to protect an induction motors from faults. When any type single phase fault is occurred in three phase induction motor then the winding of motor is heated which may goes to serious fault or may reduce the life of motor. Therefore the protection of three phase ac motor is so much necessary. So many protection devices are available in market, but they are so much costly as well as they are not so much efficient and reliable. To overcome these issues here we have designed a system that is called a three phase induction motor protection system using pic microcontroller with the help of current sensing circuit, temperature sensor, Relays with bulbs, power supply unit and PIC microcontroller PIC16f72. This three phase induction motor protection system using PIC microcontroller is more efficient, reliable and less costly as compared to other motor protection devices, but this system will only work in electrical fault condition. In this project we are using 6 bulbs along with 3 relays as three phase supply. In this we are connecting two bulbs along with relay in each phase. This system consists of three voltage sensing circuits for sensing the presence of high voltage in the respective circuits. One of the voltage sensors is connected to phase line of the supply and the other is connected to neutral line. Temperature sensor is uses to detect the temperature. A microcontroller based control system continuously monitors the temperature,voltages in all the three phases of the power supply circuit. But, when any of the phase gets disconnected then in such situations the microcontroller will isolate the three phase power through relays. In this we are using three switches to create a fault manually.  

The main objectives of the project are:

1. Automatic monitoring of all the phases.
2. Automatic switching OFF the motor if any of phases is off.

The project provides the following learning’s:  

1. Conversion of AC supply to DC supply.
2. Embedded C programming.
3. Interfacing 3-phase supply to Microcontroller.
4. PCB designing.
5. Relay operation and interfacing.

    The major building blocks of this project are:   

1. Regulated Power supply.
2. PIC Microcontroller.
3. Voltage sensing circuit.
4. Temperature sensor.
5. Relay with driver.
6. Reset.
7. Crystal oscillator.
8. LED indicators.

  Software’s used:    

• PIC-C compiler for Embedded C programming.
• PIC kit 2 programmer for dumping code into Micro controller.
• Express SCH for Circuit design.

       

Block Diagram

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