Automatic Power Factor Detector and Corrector Report

5/20/2020
REPORT ON
By
MR. SOUVIK DUTTA, UNIVERSITY ROLL NO. 25501616019
MR. AVIJIT HALDER, UNIVERSITY ROLL NO. 25501616028
MR. ARITRA DAS, UNIVERSITY ROLL NO. 25501617005
MR. SUDIP DAS, UNIVERSITY ROLL NO. 25501616018
MR. ARIJIT DEY, UNIVERSITY ROLL NO. 25501617006
Under the Guidance of PRATHITA ROY
DEPARTMENT OF ELECTRICAL ENGINEERING
DR. SUDHIR CHANDRA SUR DEGREE
ENGINEERING COLLEGE
Academic Year – 2019-20
AUTOMATIC POWER FACTOR DETECTOR AND
CORRECTOR USING ARDUINO UNO
The Project Report submitted in partial fulfilment of the requirements of the
degree of BACHELOR OF ENGINEERING
MADE BY SOUVIK DUTTA

CERTIFICATE
It is certified that the work contained in the project report titled
“Automatic Power Factor Detector and Correction Using Arduino” by
SOUVIK DUTTA has been carried out under my/our supervision and that this
work has not been submitted elsewhere for a degree.
Signature of Supervisor(s)
Name(s)
Department(s)
College Name
Month, Year

DECLARATION
I declare that this written submission represents my ideas in my
own words and where others ideas or words have been included, I have
adequately cited and referenced the original sources. I also declare that I
have adhered to all principles of academic honesty and integrity and have
not misrepresented or fabricated or classified any idea, data, fact and
source in my submission. I understand that any violation of the above will
be cause for disciplinary action by the Institute and can also evoke penal
action from the sources which have thus not been properly cited or from
whom proper permission has not been taken when needed.
Signature
Name of the student
SOUVIK DUTTA
Roll No. 25501616019
Date: 20/05/2020

APPROVAL SHEET
This project report entitled Automatic Power Factor Detector and
Correction Using Arduino by Souvik Dutta is approved for the degree of
____________ (Degree details).
Examiners
1._______________________
2.________________________
3.________________________
Supervisor (s)
________________________
________________________
________________________
Chairman
________________________
Head of the Department
________________________
Date: ____________
Place: ____________

ACKNOWLEDGEMENT
I would like to take the opportunity to express my heartful gratitude
to the people whose help and co-ordination has made this project a success.
I thank Prathita Roy Sir and Debki Kumar Ghosh Sir for knowledge,
guidance and co-operation in the process of making this project.
I owe project success to my guide and convey my thanks to them. I
would like to express my heartful gratitude towards all the teachers and staff
members of Electrical Engineering department as well as the H.O.D. Prof.
Anirban Choudhury of DSCSDEC for their full support. I would like to
thank my principal for giving us conductive environment in the institution.
I am grateful to the library staff of DSCSDEC for the numerous books,
magazines made available for handy reference and use of internet facility.
Lastly, I am also indebted to all those who have indirectly contributed
in making this project successful.

ABSTRACT
In recent years, the power quality of the ac system has become great
concern due to the rapidly increased numbers of electronic equipment, power
electronics and high voltage power system. Most of the commercial and
industrial installation in the country has large electrical loads which are severally
inductive in nature causing lagging power factor. Distribution companies
penalize for bad power factor. This situation is taken care by PFC.
Power factor correction is the capacity of absorbing the reactive power
produced by a load. In case of fixed loads, this can be done manually by
switching of capacitors, however in case of rapidly varying and scattered loads
it becomes difficult to maintain a high power factor by manually switching
on/off the capacitors in proportion to variation of load within an installation.
This drawback is overcome by using an Automatic Power Factor Correction
panel.
In this paper measuring of power factor from load is done by using
Atmega328 microcontroller and trigger required capacitors in order to
compensate reactive power and bring power factor near to unity.

Abbreviations
A - Ampere
V - Volt
P - Power
Q - Reactive Power
S - Apparent Power
PCB - Printed Circuit Board
PIC - Peripheral Interface Controller
IEEE - Institution of Electrical and Electronic Engineering
IC - Integrated Circuit
SPI - Serial Peripheral Interface
R - Resistor
L - Inductance
C - Capacitor
X - Reactance
Z - Impedance
KW - Kilo-Watt
KVa - kilo-volt-ampere
kVAr - kilo-volt-ampere-reactive
P.F. - Power Factor
I - Current
CFL - Compact Fluorescent Lamp
Tx – Transformer

SR NO TOPIC NAME PAGE
NO
1 Introduction 1
2 Review of Literature 2
2.1 Power factor 3
2.2 Power factor correction 4
2.3 Disadvantage of low power factor 4
2.4 Advantage of improved power factor 5
2.5 Power factor and electrical loads 5
2.6 Role of Capacitor 6
2.7 Uses of Automatic Power Factor Correction 7
2.8 Fixed versus Automatic capacitors 7
3 Proposed System 8
3.1 Proposed system 9
3.2 Principle of Operation 9
4 Circuit Design and Hardware Principle 10
4.1 Power Supply Circuit 11
4.1.1 Power supply Components 12
Voltage transformer 12
Diodes 12
Electrolytic capacitors 13
Voltage Regulators 13
4.1.2 Circuit diagram power supply 15
4.1.3 Working Principle 15
4.2 Sensing and Measurement Circuit 16
4.2.1 components 16
Current Transformer 16
Potential Transformer 17
Zero Crossing Detector 18
Summer/Adder X-OR gate 19
4.2.2 Output of X-Or in Different Loads 20
4.3 Control and Monitoring Circuit 22
CONTENT

SR NO TOPIC NAME PAGE
NO
4.3.1 Components 22
Microcontroller 22
Relay module 25
Capacitor Bank 26
LCD screen 27
4.4 Overall Circuit Description 30
4.5 Mathematical Calculation 32
5 Software 33
5.1 Software Development Environment 34
5.2 Programming 36
6 Project Costing 38
7 Conclusion & Reference 41
7.1 Conclusion 42
7.2 Reference 42

LIST OF FIGURES
FIG. NO. TITLE NAME PAGE NO.
1 Power Triangle 3
2 Phase-shift due to different types of
electrical loads.
6
3 Typical average power factor values for
some inductive loads.
6
4 Microcontroller base automatic
controlling of power factor compensator
circuit.
9
5 Voltage Transformer/Potential
transformer.
12
6 Diode 12
7 Electrolytic capacitor 470µF 63V. 13
8 Electrolytic capacitor 100µF 63V. 13
9 Voltage Regulator LM7805 pinout. 14
10 Voltage Regulator LM7812 pinout. 14
11 Power Supply Circuit. 15
12 Power Factor Measurement Circuit. 16
13 Secondary Winding of a Ring CT. 17
14 Potential Transformer used as an
Measurement Transformer.
17
15 Zero-Crossing Detector Using UA741
op-amp IC.
18
16 Zero-Crossing Detector Using 741 IC -
Waveforms.
18
17 74HCT86 IC architecture. 19
18 X-OR gate and Truth table. 19
19 Current and Voltage inputs to the X-OR
gate and the output on purely Resistive
load.
21

FIG. NO. TITLE NAME PAGE NO.
20 Current and Voltage inputs to the X-OR
gate and the output on Resistive and
Inductive Load.
21
21 Schematic for Control and monitoring. 22
22 Arduino UNO Board. 22
23 Arduino UNO Board Pinout. 23
24 Schematic Diagram of The Sugar Cube
relay.
26
25 Relay module used for Arduino. 26
26 Capacitor bank used in large industries. 27
27 LCD display pin layout. 28
28 Connection of LCD panel with Arduino. 29
29 Table for Power Factor Multiplier. 31
30 The main programming window of the
Arduino IDE.
35

1. Introduction:
In the present technological revolution, power is very precious and the
power system is becoming more and more complex with each passing day. As
such it becomes necessary to transmit each unit of power generated over
increasing distances with minimum loss of power. However, with increasing
number of inductive loads, large variation in load etc. the losses have also
increased parallelly. Hence, it has become prudent to find out the causes of
power loss and improve the power system. Due to increasing use of inductive
loads, the load power factor decreases considerably which increases the losses
in the system and hence power system losses its efficiency.
An Automatic power factor correction device reads power factor from
line voltage and line current by determining the delay in the arrival of the current
signal with respect to voltage signal from the source with high accuracy by using
an internal timer. It determines the phase angle lag (ø) between the voltage and
current signals and then determines the corresponding power factor (cos ø).
Then the microcontroller calculates the compensation requirement and
accordingly switches on the required number of capacitors from the capacitor
bank until the power factor is normalized to about unity.
Automatic power factor correction techniques can be applied to industrial
units, power systems and also households to make them stable. As a result, the
system becomes stable and efficiency of the system as well as of the apparatus
increases. Therefore, the use of microcontroller-based power factor corrector
results in reduced overall costs for both the consumers and the suppliers of
electrical energy. Power factor correction using capacitor banks reduces reactive
power consumption which will lead to minimization of losses and at the same
time increases the electrical system‘s efficiency. Power saving issues and
reactive power management has led to the development of single-phase
capacitor banks for domestic and industrial applications.
The development of this project is to enhance and upgrade the operation
of single-phase capacitor banks by developing a microprocessor-based control
system.

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CHAPTER 2
REVIEW OF
LITERATURE

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2.1 Power Factor:
Power factor is an energy concept that is related to power flow in electrical
systems. To understand power factor, it is helpful to understand three different
types of power in electrical systems.
Real Power is the power that is actually converted into useful work for
creating heat, light and motion. Real power is measured in kilowatts (kW) and
is totalized by the electric billing meter in kilowatt-hours (kWh). An example of
real power is the useful work that directly turns the shaft of a motor Reactive
Power is the power used to sustain the electromagnetic field in inductive and
capacitive equipment. It is the non- working power component. Reactive power
is measured in kilovolt-amperes reactive (kVAR). Reactive power does not
appear on the customer billing statement.
Total Power or Apparent power is the combination of real power and
reactive power. Total power is measured in kilovolt-amperes (kVA) and is
totalized by the electric billing meter in kilovolt-ampere-hours (kVAh).
Definition: Power factor (PF) is defined as the ratio of real power to total power,
and is expressed as a percentage (%)
Or
Power factor cos φ is defined as the ratio between the Active component IR and
the total value of the current I; φ is the phase angle between the voltage and the
current.
Fig 1: Power Triangle

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2.2 Power Factor Correction:
Power factor correction is the process of compensating for the lagging
current by creating a leading current by connecting capacitors to the supply. A
sufficient capacitance can be connected so that the power factor is adjusted to be
as close to unity as possible.
Power factor correction (PFC) is a system of counteracting the undesirable
effects of electric loads that create a power factor that is less than one (1). Power
factor correction may be applied either by an electrical power transmission utility
to improve the stability and efficiency of the transmission network or, correction
may be installed by individual electrical customers to reduce the costs charged to
them by their electricity service provider.
An electrical load that operates on alternating current requires apparent
power, which consists of real power and reactive power. Real power is the power
actually consumed by the load. Reactive power is repeatedly demanded by the
load and returned to the power source, and it is the cyclical effect that occurs
when alternating current passes through a load that contains a reactive
component. The presence of reactive power causes the real power to be less than
the apparent power, so the electric load has a power factor of less than one.
2.3 Disadvantage of Poor Power Factor:
The reactive power increases the current flowing between the power source
and the load, which increases the power losses through transmission and
distribution lines. This results in operational and financial losses for power
companies. Therefore, power companies require their customers, especially those
with large loads, to maintain their power factors above a specified amount
especially around ally 0.90 or higher, or be subject to additional charges.
Electrical engineers involved with the generation, transmission,
distribution and consumption of electrical power have an interest in the power
factor of loads because power factors affect efficiencies and costs for both the
electrical power industry and the consumers. In addition to the increased
operating costs, reactive power can require the use of wiring, switches, circuit
breakers, transformers and transmission lines with higher current capacities.

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2.4 The Advantages of an Improved Power Factor:
Higher power factors result in:
• Reduction in system losses, and the losses in the cables, lines, and feeder
circuits and therefore lower cable sizes could be opted for.
• Improved system voltages, thus enable maintaining rated voltage to
motors, pumps and other equipment.
• The voltage drop in supply conductors is a resistive loss, and wastes
power heating the conductors.
• Improving the power factor, especially at the motor terminals, can
improve the efficiency by reducing the line current and the line losses.
• Improved voltage regulation.
• Increased system capacity, by release of KVA capacity of transformers
and cables for the same KW, thus permitting additional loading without
immediate expansion.
2.5 Power Factor and Electrical Loads:
In general, electrical systems are made up of three components: resistors,
inductors and capacitors. Inductive equipment requires an electromagnetic field
to operate. Because of this, inductive loads require both real and reactive power
to operate. The power factor of inductive loads is referred to as lagging, or less
than 100%, based upon our power factor ratio.
In most commercial and industrial facilities, a majority of the electrical
equipment acts as a resistor or an inductor. Resistive loads include incandescent
lights, baseboard heaters and cooking ovens. Inductive loads include fluorescent
lights, AC induction motors, arc welders and transformers.

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2.6 Role of Capacitors:
A capacitor (originally known as condenser) is a passive two-terminal
electrical component used to store energy in an electric field. The forms of
practical capacitors vary widely, but all contain at least two electrical conductors
separated by a dielectric (insulator).
Capacitors are widely used as parts of electrical circuits in many common
electrical devices. When there is a potential difference (voltage) across the
conductors, a static electric field develops across the dielectric, causing positive
charge to collect on one plate a negative charge on the other plate. Energy is
stored in the electrostatic field.
Capacitors also require reactive power to operate. However, capacitors and
inductors have an opposite effect on reactive power. The power factors for
capacitors are leading. Therefore, capacitors are installed to counteract the effect
of reactive power used by inductive equipment.
Fig 2: Phase-shift due to different types of electrical loads.
Fig 3: Typical average power factor values for some inductive loads.

7 | P a g e
2.7 Uses of Automatic Power Factor Correction:
When the load conditions and power factor in a facility change frequently,
the demand for power factor improving capacitors also changes frequently. In
order to assure that the proper amount of power factor capacitor kVARs are
always connected to the system (without over-correcting), an Automatic Type
Capacitor System should be used for applications involving multiple loads.
A microcontroller automatic compensation system is formed by: i) Some
sensors detecting current and voltage signals; ii) An intelligent unit that compares
the measured power factor with the desired one and operates the connection and
disconnection of the capacitor banks with the necessary reactive power (power
factor regulator); iii) An electric power board comprising switching and
protection devices; iv) Some capacitor banks.
2.8 Fixed Versus Automatic Capacitors:
Fixed capacitor banks are always on at all times, regardless of the load in
the facility, while an automatic capacitor bank varies the amount of correction
supplied to an electrical system. An automatic capacitor is much more expensive
per kVAr than a fixed system. 100 kVAr of fixed capacitors will save as much
power factor penalties as a 100 kVAr automatic capacitor. Generally, when a
capacitor is connected to a system there is a reduction in amperage on the system.
This reduction in amperage reduces the voltage drop across a transformer, which
results in a higher voltage in the system. If 100 kVAr is connected to a 1000 KVA
transformer, there is approximately a ¾% voltage rise on the system (if there are
no other loads on the system). The more kVAr connected, the higher the voltage
rise. This voltage rise is counter acted by the increase of load in the facility.
Typically, in the night and on weekends, utility voltage are higher than normal,
and facilities that are not normally loaded during these times, could experience a
higher than normal voltage rise if too much capacitance is connected to their
system. Based on this, we generally limit fixed capacitors to 10% to 15% fixed
kVAr to KVA of transformer size. We would recommend an automatic capacitor
bank if the amount of kVAr exceeds 20% of the KVA size of the transformer.

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CHAPTER 3
PROPOSED SYSTEM

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3.1 Proposed System:
3.2 Principle of Operation:
The principal element in the circuit is PIC microcontroller. The current and
voltage single are acquired from the main AC line by using Current Transformer
and Potential Transformer. These acquired signals are then pass on the zero
crossing detectors. Bridge rectifier for both current and voltage signals transposes
the analog signals to the digital signal. Microcontroller read the RMS value for
voltage and current used in its algorithm to select the value of in demand capacitor
for the load to correct the power factor and monitors the behaviour of the enduring
load on the basis of current depleted by the load.
In case of low power factor Microcontroller send out the signal to
switching unit that will switch on the in-demand value of capacitor. The tasks
executed by the microcontroller for correcting the low power factor by selecting
the in demand value of capacitor and load monitoring are shown in LCD.
Fig 4: Microcontroller based automatic controlling of power factor
compensator circuit.

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CHAPTER 4
CIRCUIT DESIGN
AND HARDWARE

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Principle:
The given circuit Fig.4 for Automatic Power Factor detection and
correction operates on the principal of constantly monitoring the power factor of
the system and to initiate the required correction in case the power factor is less-
than the set value of power factor. The current and voltage signals are sampled
by employing instrument transformers connected in the circuit. The instrument
transformers give stepped down values of current and voltage, whose magnitude
is directly proportional to the circuit current and voltage. The sampled analog
signals are converted to suitable digital signals by the zero crossing detectors,
which changes state at each zero crossing of the current and voltage signals. The
ZCD signals are then added in order to obtain pulses which represent the time
difference between the zero crossing of the current and voltage signals.
The time period of these signals is measured by the internal timer circuit
of the Arduino by using the function pulseIn(), which gives the time period in
micro seconds. The time period obtained is used to calculate the power factor of
the circuit. Now if the calculated power factor is less than the minimum power
factor limit set at about 0.96-0.98, then the microcontroller switches on the
require number of capacitors until the power factor is greater than or equal to the
set value.
The overall system works in three different parts one is powering circuit,
one is sensing and measuring and the last circuit which operates the capacitor
bank using Arduino also displays power factor of connected load.
4.1 Power Supply Circuit:
A good power supply is very essential as it powers all the other modules of the
circuit. In this power supply we use step-down transformer, IC regulators, Diodes,
Capacitors and resistors (presets and pots).
We can take power from 230V line to operate the devices that will carry out
automatic process. But microcontrollers and sensing devices are mostly operates
on DC. So we need a constant DC supply.

12 | P a g e
4.1.1 Components:
A. Voltage Transformer or Potential Transformer:
A voltage transformer or a potential transformer is a wire-wound, static
electromagnetic device that is used to transform the voltage level of input voltage.
A transformer has two windings: a primary winding to which the input is
connected and a secondary winding from which the transformed voltage is
obtained. The input voltage is transformed (either stepped up or down) according
to the turn’s ratio of the primary and the secondary windings. The transformer
used in the power supply here gives an output of +12V or -12V or a total of 24V
for an input voltage of 230V.
Voltage transformers are a parallel
connected type of instrument
transformer. They are designed to
present negligible load to the supply
being measured and have an accurate
voltage and phase relationship to enable
accurate secondary connected metering
The voltage transformer used in the
power supply is designed for single
phase 230 V, 50Hz. It has three terminals
in the secondary side, the output is taken from the two end wires and is equal to
24V, because the voltage regulator should have an input voltage much greater
than the output voltage. Used here is center tap 230/12-0-12 transformer.
B. Diodes:
A diode is a two-terminal electronic component that conducts current primarily
in one direction; it has low resistance in one direction, and high resistance in the
other. Used here IN4007 diodes.
Fig 5: Voltage Transformer/Potential
transformer.
Fig 6: Diode.

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C. Electrolytic Capacitor:
An electrolytic capacitor is a capacitor that uses an electrolyte (an ionic
conducting liquid) as one of its plates to achieve a larger capacitance per unit
volume than other types, but with performance disadvantages. All capacitors
conduct alternating current (AC) and block direct current (DC) and can be used,
amongst other applications, to couple circuit blocks allowing AC signals to be
transferred while blocking DC power, to store energy, and to filter signals
according to their frequency. Most electrolytic capacitors are polarized; hence,
they can only be operated with a lower voltage on the terminal marked "-" without
damaging the capacitor. Used here is 470µF 63V, 100µF 63V and electrolytic
capacitor.
D. Voltage Regulators (7805, 7812):
Voltage regulator is any electrical or electronic device that maintains the voltage
of a power source within acceptable limits. The voltage regulator is needed to
keep voltages within the prescribed range that can be tolerated by the electrical
equipment using that voltage.
A voltage regulator may be a simple "feed-forward" design or may include
negative feedback control loops. It may use an electromechanical mechanism, or
electronic components. Depending on the design, it may be used to regulate one
or more AC or DC voltages.
Fig 7: Electrolytic capacitor
470µF 63V.
Fig 8: Electrolytic capacitor
100µF 63V.

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Electronic voltage regulators are found in devices such as computer power
supplies where they stabilize the DC voltages used by the processor and other
elements. In automobile alternators and central power station generator plants,
voltage regulators control the output of the plant. In an electric power distribution
system, voltage regulators may be installed at a substation or along distribution
lines so that all customers receive steady voltage independent of how much power
is drawn from the line.
Electronic voltage regulators utilize solid-state semiconductor devices to
smooth out variations in the flow of current. In most cases, they operate as
variable resistances; that is, resistance decreases when the electrical load is heavy
and increases when the load is lighter.
HERE we use 2 types of voltage regulators of lm78XX series such as 7805 and
7812.
Pinout Diagram of an LM78XX Voltage Regulator Series:
The LM78XX series of three terminal positive regulators with several fixed
output voltages, making them useful in a wide range of applications. Each type
employs internal current limiting, thermal shut down and safe operating area
protection, making it essentially indestructible. If adequate heat sinking is
provided, they can deliver over 1A output current. Although designed primarily
as fixed voltage regulators, these devices can be used with external components
to obtain adjustable voltages and currents.
Fig 9: Voltage Regulator
LM7805 pinout.
Fig 10: Voltage Regulator
LM7812 pinout.

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4.1.2 Circuit Diagram:
4.1.3 Working Principle:
In Fig. 11 we take power using a stepdown transformer 230V/12-0-12V, a centre
tap transformer. Then one part, across 12V and 0V taken to rectifier setup
D1,..,D4 then a 470µF capacitor across for filtering and to the LM7805 voltage
regulator another capacitor about any value between 10-100µF connected to get
a 5V DC out to power Arduino and other devices.
Second part, across 12V and 0V taken to rectifier setup D5,..,D8 then a 470µF
capacitor across for filtering and to the LM7812 voltage regulator another
capacitor about any value between 10-100µF connected to get a 12V DC out to
power Arduino and other devices.
Fig 11: Power Supply Circuit.

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4.2 Sensing and Measurement Circuit:
4.2.1 Sensing and Measurement Components:
A. Current Transformer:
The current transformer is an instrument transformer used to step-down the
current in the circuit to measurable values and is thus used for measuring
alternating currents. When the current in a circuit is too high to apply directly to
a measuring instrument, a current transformer produces a reduced current
accurately proportional to the current in the circuit, which can in turn be
conveniently connected to measuring and recording instruments. A current
Transformer isolates the measuring instrument from what may be a very high
voltage in the monitored circuit. Current transformers are commonly used in
metering and protective relays. Like any other transformer, a current transformer
has a single turn wire of a very large cross section as its primary winding and the
secondary winding has a large number of turns, thereby reducing the current in
the secondary to a fraction of that in the primary. Thus, it has a primary winding,
a magnetic core and a secondary winding. The alternating current in the primary
produces an alternating magnetic field in the magnetic core, which then induces
an alternating current in the secondary winding circuit. An essential objective of
a current transformer design is to ensure the primary and secondary circuits are
efficiently coupled, so the secondary current is linearly proportional to the
primary current.
Fig 12: Power Factor Measurement Circuit.

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Also known commonly as a Ring C.T, the current carrying conductor is simply
passed through the center of the winding. The
conductor acts as the primary winding and the
ring contains the secondary winding.
A 220Ω resistor is connected across the output
terminals of the current transformer‘s secondary
winding, this is because the microcontroller
cannot sense the current directly but it is applied
in the form of a voltage across a resistor. Also it
is called as phantom load otherwise if C.T kept
open circuited high voltage induced in
secondary may damage C.T. Here we use a
1000:1 ratio current transformer.
B. Potential Transformer:
A potential transformer or a voltage transformer is the most common type of
transformer widely used in electrical power transmission and appliances to
convert mains voltage to low voltage in order to power low power electronic
devices. They are available in power ratings ranging from mW to MW. The
Insulated laminations minimize eddy current losses in the iron core.
A potential transformer is typically described by its voltage ratio from
primary to secondary. A 600:120 potential transformer would provide an output
voltage of 120V when a voltage of 600V is impressed across the primary winding.
The potential transformer here has a voltage ratio of 230:24 i.e., when the input
voltage is the single phase voltage 230V, the output is 24V.
The potential transformer here is being
used for voltage sensing in the line. They are
designed to present negligible load to the supply
being measured and have an accurate voltage
ratio and phase relationship to enable accurate
secondary connected metering. The potential
transformer is used to supply a voltage of about
12V to the Zero Crossing Detectors for zero
crossing detection. The outputs of the potential
transformer are taken from one of the
peripheral terminals and the central
Fig 13: Secondary Winding of a
Ring CT.
Fig 14: Potential Transformer used as an
Measurement Transformer.

18 | P a g e
terminal as only a voltage of about 12V is sufficient for the operation of Zero
crossing detector circuit.
C. Zero crossing detector:
A zero crossing is a point where the sign of a mathematical function changes (e.g.
from positive to negative), represented by the crossing of the axis (zero value) in
the graph of the function. In alternating current the zero-crossing is the
instantaneous point at which there is no voltage present. Ina a sine wave this
condition normally occurs twice in a cycle.
Zero Crossing Detector using 741 IC
The zero crossing detector non-inverting circuit is an important application of
the op-amp comparator circuit. It can also be called as the sine to square wave
converter. Anyone of the inverting or non-inverting comparators can be used as
a zero-crossing detector. The only change to be brought in is the reference voltage
with which the input voltage is to be compared, must be made zero (Vref = 0V).
An input sine wave is given as Vin.
These are shown in the circuit diagram and input and output waveforms of an
non-inverting comparator with a 0V reference voltage.
As shown in the waveform, for a reference voltage 0V, when the input sine
wave passes through zero and goes in positive direction, the output voltage Vout
is driven into negative saturation. Similarly, when the input voltage passes
through zero and goes in the negative direction, the output voltage is driven to
positive saturation. The diodes D1 and D2 are also called clamp diodes. They are
Fig 15: Zero-Crossing Detector Using
UA741 op-amp IC.
Fig 16: Zero-Crossing Detector Using
741IC -Waveforms.

19 | P a g e
used to protect the op-amp from damage due to increase in input voltage. They
clamp the differential input voltages to either +0.7V or -0.7V.
In certain applications, the input voltage may be a low frequency
waveform. This means that the waveform only changes slowly. This causes a
delay in time for the input voltage to cross the zero-level. This causes further
delay for the output voltage to switch between the upper and lower saturation
levels. At the same time, the input noises in the op-amp may cause the output
voltage to switch between the saturation levels. Thus zero crossing are detected
for noise voltages in addition to the input voltage. These difficulties can be
removed by using a regenerative feedback circuit with a positive feedback that
causes the output voltage to change faster thereby eliminating the possibility of
any false zero crossing due to noise voltages at the op-amp input.
D. Summer/Adder (X-OR) gate:
XOR gate ( Exclusive OR) is a digital logic gate that gives a true (1 or HIGH)
output when the number of true inputs is odd. An XOR gate implements
an exclusive or; that is, a true output results if one, and only one, of the inputs to
the gate is true. If both inputs are false (0/LOW) or both are true, results a false
output. XOR represents the inequality function, i.e., the output is true if the inputs
are not alike otherwise the output is false.
General description: The ‘74HC86 and ‘74HCT86 contain four independent
EXCLUSIVE OR gates in one package. They provide the system designer with a
means for implementation of the EXCLUSIVE OR function.
Fig 18: X-OR gate and Truth table.
Fig 17: 74HCT86 IC architecture.

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Features of 74 HCT86:
• Two Input Exclusive-OR Gate – Quad Package
• Typical Operating Voltage: 5V
• Propagation Delay @5V : 32ns (maximum)
• Transition Time: 19ns
• Operating Temperature: -40 to +125°C
4.2.2 Output of X-OR in different loads connected:
As per the Fig. 2 shows there are three kinds of loads. i) Resistive, ii) Inductive,
iii) Capacitive. In case of a purely resistive load the voltage and current are in
phase so voltage and current meets in every zero cross points. In case of a purely
inductive load current lags behind the voltage and there is a difference between
voltage and current zero cross points. In case of purely capacitive load the current
leads the voltage by some margin and there is difference between voltage and
current zero cross points. Taking samples of connected load, using current and
voltage transformers. Now to process the measurement we need to produce digital
signals from it so Zero Cross detectors are used to produce two square wave signal
of each voltage and current. Now to compare the zero cross points we pass the
square waves to X-OR. In case zero cross points of voltage and current is a
specific time is exactly same there will be no output from X-OR , but in case of
inductive load (most common) we will find that the zero cross points of voltage
and current are not in phase or symmetric there is a difference. As per the X-OR
any difference in input there will be high output. Taking this output to the Arduino
we calculate the desired value of capacitor needs to be switched so that power
factor is maintained. As per the value of capacitor Arduino initiate the relay
modules to operate. Now capacitors connected to the line to improve the power
factor. Here capacitor bank is useful as we can minimize wide range of power
factor using various sized capacitors (considering limit of loading capacity
designed).
Then the microcontroller calculates the compensation requirement and
accordingly switches on the required number of capacitors from the capacitor
bank until the power factor is normalized to about unity.

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Fig 18: Truth Table for X-OR operation. The X-OR gate, 7486 IC DIP package
is used to add the two square wave signal outputs of the zero crossing detector
circuits of the line current and line voltage. In Fig. 20 The output of the X-OR
gate is the time lag between the zero crossing of the voltage signal and current
signal.
Fig 19: Current and Voltage inputs to the X-OR gate and the output
on purely Resistive load.
Fig 20: Current and Voltage inputs to the X-OR gate and the output
on Resistive and Inductive Load.

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4.3 Control and Monitoring Circuit:
4.3.1 Control and Monitoring Circuit components:
A. Microcontroller:
Introduction: The Microcontroller or the processing module is an interfacing
and controlling module, that interfaces the various peripherals and other modules
used in the circuit. It integrates the function of various modules such as the Zero
Crossing Detector (ZCD), X-OR gate, Relay driver (ULN2003A) etc.
Overview: The Arduino Uno is a
microcontroller board based on the
ATmega328. It has 14 digital input/output pins
(of which 6 can be used as PWM outputs), 6
analog inputs, a 16 MHz ceramic resonator, a
USB connection, a power jack, an ICSP
header, and a reset button. It contains
everything needed to support the
microcontroller; simply connect it to a computer
with a USB cable or power it with a AC-to-DC
adapter or battery to get started.
Fig 22: Arduino UNO Board.
Fig 21: Schematic for Control and monitoring.

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Communication: The Arduino Uno has a number of facilities for communicating
with a computer, another Arduino, or other microcontrollers. The ATmega328
provides UART TTL (5V) serial communication, which is available on digital
pins 0 (RX) and 1 (TX). An ATmega16U2 on the board channels this serial
communication over USB and appears as a virtual com port to software on the
computer. The '16U2 firmware uses the standard USB COM drivers,
Fig 23: Arduino UNO Board Pinout.

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and no external driver is needed. The Arduino software includes a serial monitor
which allows simple textual data to be sent to and from the Arduino board. The
RX and TX LEDs on the board will flash when data is being transmitted via the
USB-to-serial chip and USB connection to the computer (but not for serial
communication on pins 0 and 1). A Software Serial library allows for serial
communication on any of the Uno's digital pins. The ATmega328 also supports
I2C (TWI) and SPI communication. The Arduino software includes a Wire
library to simplify use of the I2C bus; see the documentation for details. For SPI
communication, use the SPI library.
Programming: The Arduino Uno can be programmed with the Arduino software
(download). Select "Arduino Uno from the Tools > Board menu (according to the
microcontroller on your board). For details, see the reference and tutorials. The
ATmega328 on the Arduino Uno comes pre burned with a bootloader that allows
you to upload new code to it without the use of an external hardware programmer.
It communicates using the original STK500 protocol (reference, C header files).
You can also bypass the bootloader and program the microcontroller through the
ICSP (In-Circuit Serial Programming) header.
Automatic (Software) Reset: Rather than requiring a physical press of the reset
button before an upload, the Arduino Uno is designed in a way that allows it to
be reset by software running on a connected computer. One of the hardware flow
control lines (DTR) of theATmega8U2/16U2 is connected to the reset line of the
ATmega328 via a 100 µfarad capacitor. When this line is asserted (taken low),
the reset line drops long enough to reset the chip. The Arduino software uses this
capability to allow you to upload code by simply pressing the upload button in
the Arduino environment. This means that the bootloader can have a shorter
timeout, as the lowering of DTR can be well-coordinated with the start of the
upload. This setup has other implications. When the Uno is connected to either a
computer running Mac OS X or Linux, it resets each time a connection is made
to it from software (via USB). For the following half-second or so, the bootloader
is running on the Uno. While it is programmed to ignore malformed data (i.e.
anything besides an upload of new code), it will intercept the first few bytes of
data sent to the board after a connection is opened. If a sketch running on the
board receives one-time configuration or other data when it first starts, make sure
that the software with which it communicates waits a second after opening the
connection and before sending this data. The Uno contains a trace that can be cut
to disable the auto-reset. The pads on either side of the trace can be soldered

25 | P a g e
together to re-enable it. It's labelled "RESETEN". You may also be able to disable
the auto-reset by connecting a 110-ohm resistor from 5V to the reset line; see this
forum thread for details.
USB Overcurrent Protection: The Arduino Uno has a resettable poly fuse that
protects your computer's USB ports from shorts and overcurrent. Although most
computers provide their own internal protection, the fuse provides an extra layer
of protection. If more than 500 mA is applied to the USB port, the fuse will
automatically break the connection until the short or overload is removed.
Physical Characteristics: The maximum length and width of the Uno PCB are
2.7 and 2.1 inches respectively, with the USB connector and power jack
extending beyond the former dimension. Four screw holes allow the board to be
attached to a surface or case. Note that the distance between digital pins 7 and 8
is 160 mil (0.16"), not an even multiple of the 100-mil spacing of the other pins.
B. Relay Module:
The relay module comprises of eight electro-magnetic relays which are controlled
by the outputs on the digital pins of the Arduino microcontroller. The relays are
used to switch on the required number of capacitors as required for power factor
correction. The relays are normally in the Normally Open (NO) state and the
contacts are closed only when the logic on any of the digital pins is high. As the
logic on a pin goes high, the Normally Open contacts of the relay are now closed
and the corresponding capacitor in connected in parallel with the load. The relay
module is interfaced with the digital pins of the Arduino microcontroller using a
parallel port and bus. The relay driver is supplied with a voltage of 12V from the
power supply. Each of the relays have an LED connected across its terminals to
indicate that the relay has been switched on and is functional.
Relay Operation: The relays used in the control circuit are high-quality Single
Pole-Double Throw (SPDT), sealed 5V Sugar Cube Relays. These relays operate
by virtue of an electromagnetic field generated in a solenoid as current is made
to flow in its winding. The control circuit of the relay is usually low power (here,
a 5V supply is used) and the controlled circuit is a power circuit with voltage
around 230V A.C. The relays are individually driven by the relay driver through
a 5V power supply. Initially the relay contacts are in the Normally Open state.
When a relay operates, the electromagnetic field forces the solenoid to move up
and thus the contacts of the external power circuit are made. As the contact is

26 | P a g e
made, the associated capacitor is connected in parallel with the load and across
the line. The relay coil is rated up to 7V, with a minimum switching voltage of
3.3V. Being able to control high load current, which can reach 250V, 10A or
125V, 15A.
C. Capacitor Bank:
A capacitor bank is a grouping of several identical or non-identical capacitors
interconnected in parallel or in series with one another. These groups of
capacitors are typically used to correct or counteract undesirable characteristics
such as power factor lag or phase shifts inherent in alternating current electrical
power supplies. Capacitor banks may also be used in direct current power
supplies to increase stored energy and improve the ripple current capacity of the
power supply. The capacitor bank consists of a group of eight (8) A.C. capacitors,
all rated at 230V, 50 Hz i.e., the supply voltage and frequency. The value of
capacitors is different and it consists of four capacitors of 2.5µfarad, two
capacitors of 4.5 farad and two remaining capacitors are rated at 10µfarads each.
All the capacitors are connected in parallel to one another and the load. The
capacitor bank is controlled by the relay module and is connected across the line.
The operation of a relay connects the associated capacitor across the line in
parallel with the load and other capacitor. Capacitor banks used in large industries
where large machines require reactive power such as inductive motors ,inductive
heaters . Capacitor banks also used in substations to limit the power factor to safe
limits.
Fig 24: Schematic Diagram of
The Sugar Cube relay.
Fig 25: Relay module used for Arduino.

27 | P a g e
D. LCD Screens:
A liquid crystal display is essentially a liquid crystal sandwiched between 2
pieces of glass, the liquid crystal reacts depending on current applied. Our LCD
is a white on black, 16 by 2 character LCD that we will use to display symbols.
Graphical LCDs also exist, but today we are just focusing on the character variety.
Each character is off by default and is a matrix of small dots of liquid crystal.
These dots make up the numbers and letters that we display on screens. The actual
coding that goes into making these characters appear is quite complicated, luckily
for you, the people over at Arduino.cc have made a library of functions for the
LCD that we can import into our sketch.
Essentially you will just need to pick a character spot on your screen and tell your
Arduino what to write there. We call the place that we are writing characters to
‘the cursor’, similar to the cursor on your PC.
The LCD also has a backlight and contrast control options. The backlight will
shine through the pieces of glass the screen is made of to display the characters
on the screen. The contrast will control how dark (or light) the characters appear.
We will use a variable resistor to control contrast, and we will set the backlight
to being on.
Fig 26: Capacitor bank used in large
industries.

28 | P a g e
Setup the Display:
1. Insert your LCD screen into your breadboard vertically such that each pin has
its own separate line on the board.
2. Insert your potentiometer in the same way.
3. Connect 5v and GND from Arduino to the + / - rails on your breadboard. This
will ground your Backlight and LCD.
4. Connect Pins 1 and 16 from the LCD screen to the negative power rail. This
will power your Backlight and LCD.
5. Connect Pins 2 and 15 from the LCD to the positive power rail. This will
power your Backlight and LCD.
6. Connect Pin 3 to the center pin of your potentiometer, this will control the
contrast.
7. Connect the top and bottom pins on your potentiometer to GND and 5v rails.
As you twist this potentiometer you will control contrast.
Fig 27: LCD display pin layout.

29 | P a g e
8. Connect Pin 4 of the LCD to pin 12 on your Arduino. This will be the register
select pin we output to from the Arduino later.
9. Connect Pin 5 of the LCD to ground.
10.Connect Pin 6 of the LCD to pin 10 on your Arduino. This is the data enable
pin that we will use later.
11.We will be using data pins 4,5,6,7 for our LCD screen. This represents 4 bits
of data, known as a nibble. The LCD screen has the capability for 8-bit
parallel communication but 4 bit will be adequate for our project.
12.Connect those pins to 4 pins on your Arduino, we use 5,4,3,2 respectively.
13.Connect your Arduino to the PC and move on!
You are going to be displaying the words HELLO WORLD on your LCD screen.
Fig 28: Connection of LCD panel with Arduino.

30 | P a g e
4.4 Overall Circuit Description:
Automatic Power Factor Correction system is based on the AVR
microcontroller Atmega 328. The voltage and current in the circuit are stepped
down using a potential transformer and a current transformer respectively. These
transformed A.C. signals are next fed to a Zero Crossing Detector (ZCD) circuit.
The output of the Zero Crossing Detector (ZCD) is a square wave, in which each
change of state represents a zero crossing of the a.c waveform. The signal goes
high on the first zero crossing of the current or voltage waveform and then goes
low on the next zero crossing of the signal, thereby generating a square wave.
Two separate Zero Crossing Detector (ZCD) circuits are used for voltage
and current waveform. The two square waves are then summed using an
Exclusive OR (X-OR) gate. The output of the summer gives the phase angle
difference which is given to the Arduino microcontroller on one of its digital I/O
pins (pin 3).
The value on the pin is read using the function pulse In(pin, value, timeout),
where the parameters pin depicts the number of the pin on which you want to read
the pulse. (int), value depicts the type of pulse to read i.e., either HIGH or LOW.
(int) and timeout (optional) depicts the number of microseconds to wait for the
pulse to start, default is one second (unsigned long). The function reads a pulse
(either HIGH or LOW) on a pin. For example, if value is HIGH, pulseIn() waits
for the pin to go HIGH, starts timing, then waits for the pin to go LOW and stops
timing. It finally returns the length of the pulse in microseconds or gives up and
returns 0 if no pulse starts within a specified time out.
The timing of this function has been determined empirically and will probably
show errors in longer pulses. Hence, it works efficiently on pulses from 10
microseconds to 3 minutes in length. The difference is measured with high
accuracy by using internal timer.
This time value obtained is in microseconds(μs). It is converted in
milliseconds (ms) and is then calibrated as phase angle φ using the relation:
Where:
φ = difference in phase angle
t = time difference in milliseconds (ms);
T = the time period of one AC cycle (i.e.,
20ms);

31 | P a g e
The corresponding power factor is calculated by taking cosine of the phase angle
obtained above (i.e., cosφ). The values are displayed in the serial monitor which
in this case is the computer screen.
The display can also be obtained on a separate display by using the serial
transmission pins: Serial Transmission (Tx) and Serial Reception (Rx) of the
Arduino but that would require appropriate interfacing circuitry. The
microcontroller then based on the algorithm then switches on the required number
of capacitors from the capacitor bank by operating the electromagnetic relays
until the power factor is normalized to the set limit.
Fig 29: Table for Power Factor Multiplier.

32 | P a g e
4.5 Mathematical Calculations:

33 | P a g e
CHAPTER 5
SOFTWARE

34 | P a g e
5.1 Software Development Environment:
The Arduino is a single-board microcontroller, intended to make the
application of interactive objects or environments more accessible. The hardware
consists of an opensource hardware board designed around an 8-bit Atmel AVR
microcontroller or a 32-bit Atmel ARM. Current models feature a USB interface,
6 analog input pins, as well as 14 digital I/O pins which allow the user to attach
various extension boards. Introduced in 2005, at the Interaction Design Institute
Ivrea, in Ivrea, Italy, it was designed to give students an inexpensive and easy
way to program interactive objects.
It comes with a simple Integrated Development Environment (IDE) that
runs on regular personal computers and allows writing programs for Arduino
using a combination of simple Java and C or C++. The Arduino Integrated
Development Environment (IDE) is a cross platform application written in Java,
and is derived from the IDE for the processing programming language and the
wiring projects. It is designed to introduce programming to artists and other
newcomers unfamiliar with software development. It includes a code editor with
features such as Syntax highlighting, Brace matching and Automatic Indentation,
and is also capable of compiling and uploading programs to the board with a
single click.
A program or code written for the Arduino is called a Sketch. The Arduino
IDE also comes with a software library called ―Wiring‖ from the original Wiring
Project, which makes many common input/outputs operations much easier. Users
need only define two functions to make a runnable cyclic executive program:
• setup(): a function run once at the start of a program that can initialize settings.
• loop(): a function called repeatedly until the board powers off .
The previous code will not be seen by a standard C++ compiler as a valid
program, so when the user clicks the “Upload to I/O Board” button in the IDE, a
copy of the code is written to a temporary file with an extra include header at the
top and a very simple main() function at the bottom to make it a valid C++
program. The Arduino IDE uses the GNU tool chain and AVR Libc to compile
programs and uses avrdude to upload programs to the board As the Arduino
platform uses Atmel microcontrollers, Atmel‘s development environment AVR
Studio or the newer Atmel Studio, may also be used to develop software for the
Arduino.

35 | P a g e
pulseIn():
• Description: The function reads a pulse
(either HIGH or LOW) on a pin. For
example, if value is HIGH, pulseIn() waits
for the pin to go HIGH, starts timing, then
waits for the pin to go LOW and stops
timing. Returns the length of the pulse in
microseconds. Gives up and returns 0if no
pulse starts within a specified time out.
The timing of this function has been
determined empirically and will probably
show errors in longer pulses. Works on
pulses from 10 microseconds to 3 minutes
in length.
• Syntax: pulseIn(pin, value)
• Parameters:
pin: the number of the pin on which you want to read the pulse. (int)value: type
of pulse to read either HIGH or LOW. (int) timeout (optional): the number of
microseconds to wait for the pulse to start; default is one second (unsigned long),
return spin the number of the pin on which you want to read the pulse. (int) value:
type of pulse to read: either HIGH or LOW. (int) timeout (optional): the number
of microseconds to wait for the pulse to start; default is one second (unsigned
long), returns the length of the pulse (in microseconds) or 0 if no pulse started
before tinmeout (unsigned long).
Fig 30: The main programming window of
the Arduino IDE.

36 | P a g e
5.2 Programming :
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 6, 5, 4, 3);// constants won't change. They're used here to
// set pin numbers:
const int buttonPin = 2; // the number of the pushbutton pin
const int ledPin = 8; // the number of the LED pin
// variables will change:
int buttonState = 0; // variable for reading the pushbutton status
void setup()
{
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
// initialize the push button pin as an input:
pinMode(buttonPin, INPUT);
lcd.begin(16, 2);
lcd.print(" A.P.F.C.A.D");
delay(10000);
}
void loop()
{
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);
// check if the pushbutton is pressed.
// if it is, the buttonState is HIGH:
if (buttonState == HIGH)
{
lcd.clear(); // Start with a blank screen

37 | P a g e
lcd.setCursor(0, 1); // Set the cursor to the second line
lcd.print("Power Factor=1");
lcd.setCursor(0, 0); // Set the cursor to the beginning
lcd.print("Resistive load");
delay(5000);
// turn LED on:
digitalWrite(ledPin, LOW);
}
else
{
lcd.print("Before PFC=0.5");
lcd.print("Inductive Load");
delay(5000);
// turn LED off:
digitalWrite(ledPin, HIGH);
lcd.print("After PFC=1");
lcd.print("Inductive Load");
// delay(5000);
}
}

38 | P a g e
CHAPTER 6
PROJECT COSTING

39 | P a g e
Cost Analysis:
Sl.
No.
Name Specification Rate
(in Rs.)
Units Total
Cost
(in Rs.)
1. Arduino UNO 400 1 400
2. Centre tap
transformer
As P.T.
230V/12-0-12V ,
250-1000mA
180 2 360
3. Current
Transformer
1000:1 ratio 500 1 500
4. 16*2 LCD display Arduino 160 1 160
5. Eurostyle
connector white
10 10 100
6. Relay module 2 Relay cube 200 1 200
7. PCB 15*9 cm 60 2 120
8. Diode IN4007 4 15 60
9. Voltage Regulator LM7812, 12V 50 1 50
10. Voltage Regulator Lm7805, 5V 90 1 90
11. Resistor 1k 1 10 10
12. Resistor 1MΩ 1 5 5
13. Resistor 1kΩ 1 5 5
14. Resistor 220Ω 1 5 5
15. Green Connector PCB mount,3 pin 12 8 96
16. Green Connector PCB mount,2 pin 10 8 80
17. Connecting wire Arduino male-male 50 1 50
18. Connecting wire Arduino male-
female
50 1 50
19. DC Jack 12V, male 15 1 15
20. Berg Strip Male-female 25 2 50
21. Variable Resistor 10k 10 6 60
22. Plyboard 1.5*1.5 ft 30 1 30
23. Connecting wire Single stranded, 3
Yard
40 1 40
24. Screw and nut 1 or 0.5 inch 3 30 90
25. Electrolytic
Capacitor
470µF/63V 20 4 80

40 | P a g e
Sl.
No.
Name Specification Rate
(in Rs.)
Units Total
Cost
(in Rs.)
26. Electrolytic
Capacitor
1000µF/63V 15 4 60
27. Electrolytic
Capacitor
100µF/63V 10 4 40
28. LED Red, green 2 5 10
29. Op-amp IC741 with base 30 6 180
30. Soldering iron 60-100W 80 1 80
31. Soldering wire 50 gm 90 1 90
32. Glue Gun 100 1 100
33. A.C. capacitor 2.5µF, 230V, 50Hz 200 1 200
34. A.C. Capacitor 4 µF, 230V, 50Hz 250 1 250
35. Incandescent lamp 100 W 10 2 20
36. Electrical ballast Choke 200 1 200
37. IC7486 XOR 40 1 40
38. Lamp holder 5A 25 2 50
39. Service Wire 1.5sqmm, 3 yard 30 1 30
40. Spacer Plastic 5mm, 100g 50 1 50
41. On off switch 5amps 30 2 60
42. 2 pin top 5amps 15 2 30
43. Striker tie 3 24 72
44. Isolation
transformer
230/230V 600 1 600
Total Cost 4868

41 | P a g e
CHAPTER 7
CONCLUSION
& REFERENCE

42 | P a g e
7.1 Conclusion:
The Automatic Power Factor Detection and Correction provides an efficient
technique to improve the power factor of a power system by an economical way.
Static capacitors are invariably used for power factor improvement in factories or
distribution line. However, this system makes use of capacitors only when power
factor is low otherwise they are cut off from line. Thus, it not only improves the
power factor but also increases the life time of static capacitors. The power factor
of any distribution line can also be improved easily by low cost small rating
capacitor. This system with static capacitor can improve the power factor of any
distribution line from load side. As, if this static capacitor will apply in the high
voltage transmission line then its rating will be unexpectedly large which will be
uneconomical & inefficient. So a variable speed synchronous condenser can be
used in any high voltage transmission line to improve power factor & the speed
of synchronous condenser can be controlled by microcontroller.
7.2 References:
• P. N. Enjeti and R Martinez, ―A high performance single phase rectifier with
input power factor correction,‖ IEEE Trans. Power Electron.vol.11, No. 2,
Mar.2003.pp 311-317
• J.G. Cho, J.W. Won, H.S. Lee, ―Reduced conduction loss zero-voltage-
transition power factor correction converter with low cost,‖ IEEE Trans.
Industrial Electron. vol.45, no 3, Jun. 2000, pp395-400
• V.K Mehta and Rohit Mehta, ―Principles of power system‖, S. Chand &
Company Ltd, Ramnagar, New delhi-110055, 4th Edition, Chapter 6.
• Dr. Kurt Schipman and Dr. Francois Delince, ―The importance of good power
quality‖, ABB power quality Belgium.
• Robert. F. Coughlin, Frederick. F. Driscoll, ―Operational amplifiers and linear
integrated circuits‖, 6thEdition, chapter 4.
• International Journal of Engineering and Innovative Technology (IJEIT)
Volume 3, Issue 4, October 2013 272 Power Factor Correction Using PIC
Microcontroller

43 | P a g e
• Design and Implementation of Microcontroller-Based Controlling of Power
Factor Using Capacitor Banks with Load Monitoring, Global Journal of
Researches in Engineering Electrical and Electronics Engineering, Volume 13,
Issue 2, Version 1.0
Year 2013 Type: Double Blind Peer Reviewed International Research Journal
Publisher: Global Journals Inc. (USA) Online ISSN: 2249-4596 & Print ISSN:
0975-5861
• Electric power industry reconstructing in India, Present scenario and future
prospects, S.N. Singh, senior member, IEEE and S.C. Srivastava, Senior Member,
IEEE.
● www.arduino.cc

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