automatic power factor correction

1. SEMINAR
ON
POWER FACTOR IMPROVEMENT USING
MICROCONTROLLER
RAJKIYA ENGINEERING COLLEGE BANDA
SESSION 2016-17
PROJECT GUIDE
MISS KUMARI GITA
Prepared by
Asst. professor
Abhishek kumar singh
(Department of electrical engg.)
Dinesh pratap singh
Diwakar Tiwari
Jogendra kumar

2. CONTENTS
1. INTRODUCTION
2. WHAT IS POWER FACTOR ?
3. CAUSES OF LOW POWER FACTOR
4. AUTOMATIC POWER FACTOR IMPROVEMENT
5. HARDWARE COMPONENT
6. ADVANTAGES OF P.F CORRECTION
7. ADVANTAGES OF APFC
8. CONCLUSION

3. INTRODUCTION
In the present scenario of technological revolution it has been observed that the
power is very precious. The industrialization is primarily increasing the
inductive loading, the Inductive loads affect the power factor so the power
system losses its efficiency. There are certain organizations developing products
and carrying R&D work on this field to improve or compensate the power
factor. The Automatic Power factor Correction device is a very useful device
for improving efficient transmission of active power. Automatic Power factor
correction device reads the power factor from line voltage and line current,
calculating the compensation requirement switch on different capacitor banks.

4. WHAT IS POWER FACTOR
 Power factor is the ratio between the KW and the KVA drawn by an
electrical load where the KW is the actual load power and the KVA
is the apparent load power. It is a measure of how effectively the
current is being converted into useful work output and more
particularly is a good indicator of the effect of the load current on
the efficiency of the supply system.
 Power factor = Actual power / Apparent power.
 Power Factor = Kilo watt / Kilo volt ampere.

5. ACTIVE POWER:
Also known as “real power” or simply “power.” Active power is the rate of
producing, transferring, or using electrical energy. It is measured in watts and often
expressed in kilowatts (KW) or megawatts (MW). The terms “active” or “real”
power are used in place of the term “power” alone to differentiate it from “reactive
power.
APPARENT POWER:
The product of the voltage (in volts) and the current (in amperes). It comprises
both active and reactive power . it is measured in “volt-amperes” and often expressed
in kilovolt-amperes(kva) or “megavolt-amperes” (MVA).

6. CAUSES OF LOW POWER FACTOR
1. Single phase and three phase induction Motors(Usually, Induction motor works.
2. Varying Load in Power System(As we know that load on power system is varying.
During low load period, supply voltage is increased which increase the magnetizing
current which cause the decreased power factor)
3. Industrial heating furnaces
4. Electrical discharge lamps (High intensity discharge lighting) Arc lamps (operate a
very low power factor).
5. Transformers
6. Harmonic Currents

7. AUTOMATIC POWER FACTOR IMPROVEMENT
 Power factor correction is the capacity of absorbing the reactive power produced by
a load.
 In industry most of the load is inductive in nature which results in lagging power
factor that is why there is loss and wastage of energy which results in high power
bills and heavy penalties from electricity boards.
 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 APFC panel.
 If the load is uneven it is very difficult to maintain unity power factor. To overcome
this difficulty APFC panel is used which maintains unity P.F.

9.  MICROCONTROLLER (ATMEGA-328)
 VOLTAGE REGULATOR (LM7805)
 POWER SUPPLY ( 5 Volt , 12 Volt )
 RELAY ( 12 VOLT)
 LCD ( 16x2)
 ZERO CROSSING DETECTOR (C.T. & P.T.)
 LED
 RESISTOR
 CAPACITOR BANK
 INDUCTIVE LOAD ( CHOCK )
HARDWARE COMPONENTS

10. MICROCONTROLLER
A Microcontroller Contains:
The processor (The CPU),
Program memory,
Memory for input and output(RAM),
A clock and an I/O control unit.
Microcontroller it is an electronic clock driven reprogrammable device which
can take some digital data , process the data and gives us to required output
data.

11. MICROCONTROLLER ATMEGA 328
The ATmega328/P is a low-power CMOS 8-bit microcontroller based on
the AVR®
enhanced RISC architecture. By executing powerful instructions
in a single clock cycle, the ATmega328/P achieves throughputs close to
1MIPS per MHz. This empowers system designer to optimize the device
for power consumption versus processing speed
Peripheral Features
Two 8-bit Timer/Counters with Separate Prescaler and Compare Mode
One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and
Capture Mode
Real Time Counter with Separate Oscillator
Six PWM Channels

12.  Temperature Measurement
 Two Master/Slave
 One Programmable Serial.
 Special Microcontroller Features-
 Power-on Reset and Programmable Brown-out Detection
 Internal Calibrated Oscillator
 External and Internal Interrupt Sources
 Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down,
Standby, and Extended Standby
 Operating Voltage:
1.8 - 5.5V
 Temperature Range:
-40°C to 105°C
 Power Consumption at 1MHz, 1.8V, 25°C

13. BLOCK DIAGRAM ATMEGA 328
CPU
On-chip
RAM
On-chip
ROM for
program
code
I/O Ports
Timer 0
Serial
Port
OSC
Interrupt
Control
External interrupts
Timer 1
Timer/Counter
Bus
Control
TxD RxDP0 P1 P2 P3
Address/Data
Counter
Inputs

14. VOLTAGE REGULATOR
A voltage regulator is designed to automatically maintain a constant voltage level.
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.
Voltage regulators perform the same function in large-scale power-distribution
systems as they do in motor vehicles and other machines; they minimize variations
in voltage in order to protect the equipment using the electricity.

15. POWER SUPPLY
 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 .
 Power supply for apfc modules is 12v dc.
 Generally 230V AC supply is available to Domestic supply so it is
needed a rectifier circuit.

16. RELAY
IT IS A ELECTRO MAGNETIC SWITCH
USED TO CONTROL THE ELECTRICAL DEVICES
COPPER CORE MAGNETIC FLUX PLAYS MAIN ROLE HERE

17. The relay's switch connections are usually labeled COM, NC and NO:
COM = Common, always connect to this; it is the moving part of the
switch.
NC = Normally Closed, COM is connected to this when the relay coil
is off.
NO = Normally Open, COM is connected to this when the relay coil is
on

18. LIQUID CRYSTAL DISPLAY (LCD)
Most common LCD connected to the microcontroller is 16x2.
This means 16 characters per line by 2 lines.

19. 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. It is a commonly used term in electronics,
mathematics, sound and image processing.
 In alternating current the zero-crossing is the instantaneous point at which there
is no voltage present. In a sine wave this condition normally occurs twice in a
cycle.
 A zero crossing detector is an important application of op-amp comparator
circuit. It can also be referred to as a sine to square wave converter. Anyone of
the inverting or the non-inverting comparators can be used as a zero crossing
detector. The reference voltage in this case is set to zero. The output voltage
waveform shows when and in what direction an input signal crosses zero volts.

20. LED
 A light-emitting diode (LED) is a
semiconductor light source.
 LEDs are used as indicator lamps in
many devices and are increasingly used
for general lighting.
 Appearing as practical electronic
components in 1962, early LEDs emitted
low-intensity red light, but modern
versions are available across the visible,
ultraviolet, and infrared wavelengths,
with very high brightness.

21. RESISTOR
 A resistor is a passive two terminal electrical component that implements
electrical resistance as a circuit element.
 The current through a resistor is in direct proportion to the voltage across the
resistor's terminals. This relationship is represented by Ohm's law

22. CAPACITOR BANK
A capacitor bank is a group of several capacitors of the same rating that are connected
in series or parallel with each other to store electrical energy .
The resulting bank is then used to counteract(resist) or correct a power factor lag or
phase shift in an alternative current (AC) power supply. They can also be used in a
direct current (DC) power supply to increase the ripple current capacity of the power
supply or to increase the overall amount of stored energy.
Capacitor banks are generally used in substation.

23. 23
Reduction in
Transformer Rating
Reduction in KVAR
Demand
Advantages of P.F
Correction
Reduction in KVA
Demand
Reduction in Line
Current
Reduction in Line
loss
Reduction in
Cable / Bus-bar
size
Reduction in
Switchgear
Rating
Avoid power factor
penalties
Increases
equipment life

24. ADVANTAGES OF APFC
 Consistently high power factor under fluctuating loads
 Prevention of leading power factor
 Eliminate power factor penalty
 Lower energy consumption by reducing losses.
 Continuously sense and monitor load
 Automatically switch on/off relevant capacitors steps for consistent power
factor.
 Ensures easy user interface
 Protect under any internal fault
24

25. CONCLUSION
It can be concluded that power factor correction techniques can be
applied to the industries, power systems and also house holds to make
them stable and due to that the system becomes stable and efficiency of
the system as well as the apparatus increases. The use of
microcontroller reduces the costs. Due to use of microcontroller
multiple parameters can be controlled and the use of extra hardwares
such as timer , RAM,ROM and input output ports reduces.

26. THANK YOU