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 Power Factor Correction
Post: #1

I need technical seminars topic on the topic power factor correction
Post: #2
[attachment=3542]

WELCOME POWER FACTOR CORRECTION

Submitted By:
Rajat Kumar Barik
Electrical Branch

INTRODUCTION

1. Power factor is the percentage of electricity that is being used to do useful work
2. Power factor =Active power/Apparent power
3. Apparent power has two component:
(a) Active power
(b)Reactive power

DEFINATION

o ACTIVE POWER: Active power does all the work.
o UNIT : kw
o P= v I cos
o REACTIVE POWER: I t is the pseudo power(false) power which flows from source to load during +ve half and load to source during â€œve half cycle.
o UNIT : Kvar
o Q= v I sin

(A)Larger kva rating of equipment

Kva = kw / cos
If cos will decrease then kva rating will increase
So we have to make equipment larger which is expensive

B)GREATER CONDUCTOR SIZE:

P =V I COS
=> I= (P/ VCOS)
If powerfactor will decrease then current will increase.
So for conducting heavy current we have to
install large size Conductor.

At low power factor the current drawn by the system will increase. Due to increase in current the copper loss will increase .

(d) Poor voltage regulation

The large current in low power factor causes a high voltage drop and the voltage at the receiving side is low.
In order to keep the constant voltage at the receiving side we have to install extra equipment (voltage regulators) is required.

EQUIPMENT CREATING POOR POWER FACTOR

o LIGHTING INCANDESCENT LAMPS.FLUORESCENT LAMP.
o MERCURY VAPOUR LAMPS.
o DISTRIBUTION TRANSFORMER.
o INDUCTION MOTOR.
o SYNCHRONOUS MOTORS
o INDUSTRIAL HEATING
o WELDING

BENEFITS OF POWER FACTOR CORRECTION
Reduce utility power bills :

(a) For consumer
: A consumer has to pay electricity charges for his maximum demand in Kva plus the unit consumed. If the consumer improves the power factor then there is a reduction in Kva requirement. So there will be a annual saving.

(b)For generating station
: Generating station is as much concerned with power factor improvement as the consumer . The generators in a power station are rated in Kva but the output will depend on Kw.
Increase system capacity
Improve operating characteristics (Gain voltage)
Improve system operating characteristics (Reduce line losses)
Types of power factor correction
Power factor correction can be made in three ways
Capacitor bank
Static correction
Bulk correction
Synchronous condenser

(1) Capacitor bank

The power factor can be improved by connecting capacitors in parallel with the equipment operating at lagging power factor .
The capacitor (generally known as static capacitor ) draws a leading current and partly naturalized the lagging reactive component of load current. This raises the power factor of the load.

Capacitor bank

DIRECTION of current before compensation
Direction of current after using capacitor bank

(2) Synchronous condenser

o A synchronous motor takes a leading current when over excited and therefore behaves as capacitor .
o An over excited synchronous motor running on no load is known as synchronous condenser. When such machine is connected in parallel with the supply , it takes a leading current which partly naturalizes the lagging reactive component of the load. Thus power factor can be improved.

V CURVE

Phase advancer are used to improve the power factor of induction motors .The low power factor of an induction motor is due to the fact that its stator winding draws exciting current which lags
behind the supply by an angle of 90 degree.
If the exciting ampere turn can provided from some other a.c source then stator winding will be relived of exciting current and the power factor can be improved.

CONCLUSION

Lastly after the completion of my seminars , I conclude that improvement of power factor is necessary in both consumer end and supplier point of view . In some industries penalty is charged due to low power factor. In some industries where power consumed by the load is low , high ratings of equipment s are required.
SVC technology and synchronous generator are used for the improvement of power factor.

Reference

http://www.seminarprojects.org
http://www.slideworld.com
V.k.mehta
R.k.rajput
Post: #3
SAKKARIYA A.P
SHAMEEM A
SHABEER ALI O.V MOHAMMED BISHRU N
RESHMA V

Power Factor Improvement

ABSTRACT

The aim of this technical report is to introduce a summary for a study done for Al-Ameen Engineering College for power factor improvement. This report includes an electrical engineering background about the problem of power factor, including: the causes, the consequences, the economical importance for the energy saving for our college and for the Kerala State Electricity Board as well, and the theoretical solution for solving that problem.

The report links the theoretical solution with the real applicable solution through the study done by our project team for energy planning. This study includes a six months research done by our team, which represents an ideal methodology for solving this problem starting from defining the magnitude of the power factor problem until designing the equipment that can solve that problem.

The report represents all the points in simple terminology, according to the objectives of the electrical engineering degree course.
1.1 What Is Power Factor
Power Factor is the ratio between the real (kW) and apparent power (kVA) drawn by an electrical load. It is a measure of how effectively the current is being converted in to useful work output and a good indicator of the effect of the load current on the efficiency of supply system. Poor power factor results in increase load current draw that causes additional losses in the supply and distribution systems.

Power Factor (pf) =

Resistive devices, like electric resistance heaters and incandescent lights transform all the power supplied to the device into heat or useful energy. Inductive devices, like motors, use some of the power supplied to the device to energize the inductive windings and create a magnetic field. This power, called reactive power, is alternately stored and given up by the windings, but is not used to do actual work. When this happens, the line supplying power to the device now carries the actual power used by the device and the reactive power created by the device.
Actual power used by the device is measured in kW, reactive power created by induction devices is measured in kVAR, and the apparent power in the supply lines is measured in kVA.

Post: #4
[attachment=6202]
CIRCUITS FOR POWER FACTOR CORRECTION
WITH REGARDS TO MAINS FILTERING

INTRODUCTION
The new European Norms EN 60555 and the international standard IEC555 will impose a limit on the harmonic content of the input current of mains supplied equipment. In practice this will require the addition of a Power Factor Corrector (PFC) at the input of many types of mains operated electronic equipment, for example electronic lamp ballasts, TV power supplies and motor drives. A correctly designed PFC draws a sinusoidal input current from the mains supply, in phase with the mains voltage, and meets the EN60555 norm. It may also provide additional functions, such as automatic mains voltage selection and a regulation of the voltage supplied to the attached equipment. Size and cost optimization of PFCs must include the RFI filter on the input, which prevents interference being fed back to the mains. The addition of the PFC represents another switching stage in the system, meaning that larger amount of high frequency noise is applied to the mains than with a conventional rectifier/capacitor front end, and so additional RFI filtering is required. The amount of fitering needed can be minimized by choosing suitable modulation techniques and mode of operation of the PFC.
Post: #5
[attachment=6583]
Power Factor Correction

The University of Texas at Austin
Austin, Texas 78712
Robert J. Gilleskie
San Diego Gas & Electric
San Diego, California 92123

Abstract

We are all familiar with power factor, but are we using it to its true potential? In this paper we
investigate the effect of harmonics on power factor and show through examples why it is

http://citeseerx.ist.psu.edu/viewdoc/dow...1&type=pdf
important to use true power factor, rather than the conventional 50/60 Hz displacement power
Introduction
Voltage and current harmonics produced by nonlinear loads increase power losses and, therefore,
have a negative impact on electric utility distribution systems and components. While the exact
relationship between harmonics and losses is very complex and difficult to generalize, the wellestablished
concept of power factor does provide some measure of the relationship, and it is
useful when comparing the relative impacts of nonlinear loads–providing that harmonics are
incorporated into the power factor definition.
Power Factor in Sinusoidal Situations
The concept of power factor originated from the need to quantify how efficiently a load utilizes
the current that it draws from an AC power system. Consider, for example, the ideal sinusoidal
situation shown in Figure
Post: #6
[attachment=14723]
Introduction
Power factor correction (PFC) is a technique of counteracting the undesirable effects of electric loads that create a power factor that is less than one. 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 supplier. In order to improve transmission efficiency, power factor correction research has become a hot topic. Many control methods for the Power Factor Correction (PFC) have been proposed.
Capacitive Power Factor correction (PFC) is applied to electric circuits as a means of minimising the inductive component of the current and thereby reducing the losses in the supply.
The introduction of Power Factor Correction capacitors is a widely recognised method of reducing an electrical load, thus minimising wasted energy and hence improving the efficiency of a plant and reducing the electricity bill.
Power factor control means to control the power factor with its rated value of 0.9 to 0.95 in any kind of the system where we want to control power factor.
The whole system is divided into 3 PART.
2. PIC 18F4520 microcontroller with LCD.
3. Capacitor bank with relay driver card.
In this project we are going to control the power factor with the use of PIC 18F4520 microcontroller chip.
We are using step by step manually operated inductive loads and also with it‟s the relay driver card to turn the capacitor bank on.
The improved power factor is displayed on the 16*2 LCD modules with the use of microcontroller.
Post: #7
to get information about the topic "power factor improvement methods" full report ppt and related topic refer the link bellow

http://seminarprojects.org/t-automation-...ull-report

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