Home Usable Microcontroller Based Mini PFI

DOI : 10.17577/IJERTV3IS10726

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Home Usable Microcontroller Based Mini PFI

Sairatun Nesa Soheli

Faculty of Electrical and Electronics Eng IUBATInternational University of Business Agriculture and Technology

Uttara, Dhaka, Bangladesh

Md. Nur Momen Hasib

Instructor of Electrical and Computer Eng TTTI- Trust Technical Training Institute BMTF, Gazipur Cant, Gazipur, Bangladesh


This paper presents home usable microcontroller based mini PFI using microcontroller chip PIC16F877A based on message scheduling which basically belongs to Micro C Program with the help of ADC (Analog to Digital Converter). It is automatically and maintenance free system. So, there is no need any user for controlling this system.

Index Item Introduction, Block Diagram, Circuit Diagram, Circuit Description

  1. Introduction

    PFI is generally used in a factory to improve the power factor for reduce the electricity bill. But it is not used in a house because its system is unknown for most of us. Its cost is so high and it occupies a large space. Nowadays microcontroller is used most of appliance all over the world. For using microcontroller it is possible to improve the efficiency and we can also reduce its cost.

    In this project there are four types of advantages. This are- its size is small, cost is low, suitable to utilize in household chore and it is maintenance free system.

  2. Methodology

    The methodology of this project is shown in below:

    It measures the load when inductive load is increased.

    • Necessary capacitive load is increased according to the inductive load.

    • It measures the load when inductive load is decreased.

    • Necessary capacitive load is decreased according to the inductive load.

    • If there is no load available, all capacitive loads are reduced.

  3. Block Diagram

    The block diagram of Home Usable Microcontroller Based Mini PFI shown in below:

  4. Working Principle

    It measures the load by using microcontroller based ADC (Analog to Digital Converter) and the peripheral of ADC (Analog to Digital Converter) current transformer. With the help of microcontroller operated relay, capacitor is connected to improve the power factor for reduce the electricity bill.

  5. Component Used

    • Microcontroller PIC16F877A, for controlling the whole system of Home Usable Microcontroller Based Mini PFI.

    • Relay, for interfacing between microcontroller and capacitor.

    • LCD screen or LED light, for knowing the position of load and capacitor and also the microcontroller.

    • Capacitor, for improvement of power factor.

    • Current transformer, for calculating load.

    • Variable resister, for adjusting microcontroller.

    • IC7805, for supplying +5Volt as a power factor.

    • Transformer, for making 220Volt to 12Volt AC supply.

    • Rectifier IN4007, for making alternative current to direct current.

    • Other accessories, for helping

  6. Circuit Operation

    Power supply provides +5 Volt supply by using regulator IC7805. Then the system is on.

    Current transformer sends a signal to the microcontroller through the variable resistance. This signal is always between 0 Volts to +5 Volts.

    Microcontroller takes signal through a variable resistor so we can adjust the signal.

    Now microcontroller measures current, voltage and ascertain Watt. After ascertain the Watt, microcontroller connect the necessary capacitive load with the help of relay.

    Here transistor workings as a relay operating switch.

    LCD shows the inductive load, capacitive load and also power factor in the screen. In order to cost reducing we can also use LED.

    Like the similar way microcontroller reduce3 all capacitive load when inductive load is zero.

  7. Algorithm

    • Step-1 Initialize the controller.

    • Step-2 Initialize the LCD.

    • Step-3 Port 2 as Input port.

    • Step-4 Confirm port 15, 16, 17 & 18 as Output port.

    • Step-5 Take the Input from Current Transformer.

    • Step-6 Connect the required capacitor through the relay.

    • Step-7 Repeat from step.

  8. Result

    This project is successfully run like our expectation.

    When load increases Microcontroller sense the load and connect capacitors. Microcontroller sense the load like a clip on ammeter we can see the result in LCD screen.

  9. Conclusion

    This PFI works precisely with the help of microcontroller. We should have to use the value of capacitor in this PFI on the load of the house. To make this PFI more precise, we should have to increase the number of capacitor. To use this PFI it is possible to save the electricity bill with low cost.

  10. Future Scope

    • It is possible to connect any kinds of meter with this system.

    • It can be transfer into PLC base system.

    • It can also provide safety switch inside the system which can able to give us the safety of electric circuit with low cost.

  11. References

  1. Douglas V.Hall, Microprocessors and Interfacing: Programming and Hardware, McGraw-Hill, 1986, the University of Michigan, 16 Nov 2007, ISBN 0070255261, 9780070255265

  2. Jan Axelson, The Microcontroller Idea Book, Lakeview Research, 5310 Chinook Ln. Madison, WI 53704 USA, copyright 1994, 1997 by Jan Axelson

  3. Joe Pardue, C Programming for Microcontrollers Featuring ATMEL's AVR Butterfly and the free WinAVR Compiler, March 1st 2005 by Smiley Micros, ISBN 0976682206.

  4. Kenneth J. Ayala, The 8051 Microcontroller: Architecture, Programming and Applications, copyright 1991 by West Publishing Company, 50

    W. Kellogg Boulevard, P. O. Box 64526, St. Paul, MN 55164-0526

  5. http://www.personal.rdg.ac.uk/~stsgrimb/teachin g/programming_pic_microcontrollers.pdf

  6. Milan Verle, PIC Microcontrollers- Programming in C, mikroElektronika; 1st edition (2009), ISBN-13: 978-86-84417-17-8

  7. http://www.indiamart.com/shethelectronics/integ rated-circuts.html

  8. http://www.seattlerobotics.org/encoder/may97/p icchip.html

  9. http://www.lirtex.com/tutorials/beginners-guide- to-microchip-pic-programming/

  10. http://www.best-microcontroller- projects.com/16F877A.html

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