Automatic Power Factor Control

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Internal guide:Mr . S.M.M.MUDASSIR

Associate Professor , EEE Dept , DCET

By

1. MOHMMED IMRAN Roll No:1603-107-34024

2. MOHAMMED MUJAHED KHAJA Roll No:1603-107-34033

3. S.MOHAMMED OSMAN Roll No:1603-107-34035



*

*Power factor (PF) is defined as the ratio of the real power (P) to

apparent power (S), or the cosine (for pure sine wave for both

current and voltage) that represents the phase angle between the

current and voltage waveforms.

*The power factor can vary between 0 and 1, and can be either

inductive (lagging) or capacitive (leading)

Some of the benefits of improving your power factor include:

*Eliminating the power factor penalty

*Increased system capacity and reduced system losses in your

electrical system

*Reducing peak KW billing demand



*

*The project aims in maintaining power factor near to 1 with the

help capacitors banks which is disturbed after introducing

inductive loads into the system.

*The method used to correct the power factor is installing ofcapacitor banks.

*Installing capacitors decreases the magnitude of reactive power

(KVAR), thus increasing your power factor.

*Incase of balanced circuit, all the energy released by theinductor is absorbed by the capacitor.



LCD driver

LCD

Micro

controller

Regulated power supply

Relay unitZero-Crossing

Detector sensor

LED indicators Crystal Oscillator

Capacitors bank230V

Power

supply

Resistive load Inductive load

Switches

Current

transformer

Potential Transformer



Operation circuit



*

*Microcontroller

*Regulated Power Supply

*Crystal Oscillator

*LED indicators

*Potential transformer

*Current transformer

*Zero crossing detector

*Relay unit

*LCD (Liquid Crystal Display)



*

*Microcontrollers are “special purpose

computers”.

*The Microcontroller includes a CPU,RAM,ROM,I/O ports, Timers etc.., like a

standard computer, but on a single silicon chip.

*Microcontroller based systems are designed to perform a specified task.

*The Microcontroller used in the project is PICMicrocontroller developed by MicrochipIncorporation



*

*PIC Microcontrollers requires a 5V DC for its operation.

*The aim of this block is to convert battery voltage to 5V DC.

*The process of conversion is shown below:



*

*An oscillator is an electronic circuit that produces

a repetitive electronic signal.

*The maximum operating frequency of PIC

Microcontrollers is 20 MHz.

*Crystal oscillator is used in the project because of

the fact that crystal is more stable to temperature

than other types of oscillators.



*

• LED (Light Emitting Diode) is a

semiconductor light source used as

indicators.

• In this project we are using LED indicators

for checking Microcontroller working

status and various status indications.

• This usually works on 2 volts, 10 mA.



*

*We are making use of PT (potential transformer) for

capturing the zero-crossing point of voltage wave

form.

*PT converts the high voltage AC to a low voltage

measurable quantity.

*PT of type step-down transformer.



*

*CT are used for current measurements.

*We are making use of CT (current transformer) for capturing the

zero-crossing point of current wave form.*CT is of type step-up transformer.



*

*Zero crossing detection is the process of finding the variation of

waveform from zero as reference point.

*In this project this is used to find out whether both current and

voltage wave forms are leading or lagging or in phase with eachother.



*

*A relay operation depends upon theelectromagnetic effects of current

flowing in an energizing winding.

*Relay is used for controlling high voltage

device using low voltage signal.

*This works on electromagnetic principle.

*Relay takes the commands from the

(microcontroller) control unit.

*It controls the high voltage electrical

devices like Lamp, Fan, Water pump,

Circuit breaker etc.



*

*A liquid crystal display (LCD) is a thin, flat electronic visual

display that uses the light modulating properties of liquid

crystals.

*The LCD display used in the project is 16X2.

*We use this display to show the power factor.



*

Advantages of power factor correction includes:

*Saves money on utility bills* Increases internal electrical system capacity

* Improve voltage drop at point of use



*

*Investment is more for extra capacitors.

*The control circuit will draw some power

continuously.



*

*Industry motors.

*Irrigation pump sets.



[1] Narendran, N. “Requirements for solid-state lighting” Conference on

Lasers and Electro-Optics, 2004. (CLEO). Vol 1, 2004

[2] DOE Solid-State Lighting CALiPER Program Summary of Results:

Round 7 of Product Testing (PDF). U.S. Department of Energy. February2009.

[3] Wei Xiong ; Stankovic, A.V.; Nerone, L.R. “Modeling and Design of L-Complementary Self-Oscillating Class D Inverter With Output VoltageClamping” IEEE Trans. on Industry Applications, vol. 49, no. 2, April 2013,

pp. 731 – 738

[4] Cosby, M.C., Jr. Nelms, R.M., “A Resonant Inverter for Electronic Ballast

Applications” IEEE Trans. on Industrial Electronics, vol. 41, no. 4, Aug 1994, pp. 418-425

[5] Kazimierczuk, M.K. ; Szaraniec, W. “Electronic ballast for fluorescentlamps” IEEE Trans. on Power Electronics, vol. 8, no. 4, 1993, pp. 386 - 395

*References



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Automatic Power Factor Control