This document provides an overview of power factor, including basics, causes of low power factor, disadvantages, correction methods, and advantages of correction. It defines power factor as the ratio of true power to apparent power. Induction motors, transformers, and other inductive loads cause low power factors. Correcting power factor reduces equipment sizes and losses, improves voltage regulation, and avoids penalties under power factor tariffs. Static capacitors and synchronous condensers are common correction methods.
the ratio of the actual electrical power dissipated by an AC circuit to the product of the r.m.s. values of current and voltage. The difference between the two is caused by reactance in the circuit and represents power that does no useful work.
the ratio of the actual electrical power dissipated by an AC circuit to the product of the r.m.s. values of current and voltage. The difference between the two is caused by reactance in the circuit and represents power that does no useful work.
The cosine of angle made between the voltage and current is called the power factor.
In AC circuits, there is always the phase deference between the voltage and current, which is calculated in terms of power factor.
If the load is inductive the current lags behind the voltage and the power factor is lagging.
If the load is capacitive the current leads the voltage and the power factor is leading.
The value of power factor can never be more than unity.
Automatic generation control (AGC) is a system for adjusting the power output of multiple generators at different power plants, in response to changes in the load. Since a power grid requires that generation and load closely balance moment by moment, frequent adjustments to the output of generators are necessary. The balance can be judged by measuring the system frequency; if it is increasing, more power is being generated than used, which causes all the machines in the system to accelerate. If the system frequency is decreasing, more load is on the system than the instantaneous generation can provide, which causes all generators to slow down.
Introduction to reactive power control in electrical powerDr.Raja R
Introduction to reactive power control in electrical power
Reactive power in transmission line :
Reactive power control
Reactive power and its importance
Apparent Power
Reactive Power
Apparent Power
Reactive Power Formula
The cosine of angle made between the voltage and current is called the power factor.
In AC circuits, there is always the phase deference between the voltage and current, which is calculated in terms of power factor.
If the load is inductive the current lags behind the voltage and the power factor is lagging.
If the load is capacitive the current leads the voltage and the power factor is leading.
The value of power factor can never be more than unity.
Automatic generation control (AGC) is a system for adjusting the power output of multiple generators at different power plants, in response to changes in the load. Since a power grid requires that generation and load closely balance moment by moment, frequent adjustments to the output of generators are necessary. The balance can be judged by measuring the system frequency; if it is increasing, more power is being generated than used, which causes all the machines in the system to accelerate. If the system frequency is decreasing, more load is on the system than the instantaneous generation can provide, which causes all generators to slow down.
Introduction to reactive power control in electrical powerDr.Raja R
Introduction to reactive power control in electrical power
Reactive power in transmission line :
Reactive power control
Reactive power and its importance
Apparent Power
Reactive Power
Apparent Power
Reactive Power Formula
Application of Capacitors to Distribution System and Voltage RegulationAmeen San
Application of Capacitors to
Distribution System and Voltage
Regulation
POWER FACTOR IMPROVEMENT,
System Harmonics
Voltage Regulation
Methods of Voltage Control
Improvement of Load Power Factor by Using CapacitorIOSRJEEE
Series and parallel capacitors in the power system effect reactive power to improve power factor and voltage because of increasing the system capacity and reducing losses. Reactive power of series capacitor is the same to the current. There are certain unpleasant aspects in the capacitor series. Generally, the cost to install a series capacitor is higher than parallel capacitor. It is caused by complex protection equipment for series capacitor and designing series capacitors for greater power than parallel capacitor to solve the future cost. Installation of capacitors is important to reduce of a system reactive power. Transmission line would be most economical if it is used to send active power where the need of reactive power can be obtained by distribution system in substation level. This will allow user in optimum transmission line, improve operational performance and reduce energy losses. It requires a system and planning carefully to fulfill the need of system reactive power in the same way with active power planning and it is programmed an additional generator capacity.
Power Factor Correction Methods
Fixed Capcitors
Synchronous Condensors
Phase Advancers
Switch Capacitors
Static Var Compensator(SVC)
Static Synchronous Compensator(STATCOM)
Modulated power filter capacitor compensator
Economics of power factor improvement
Economical comparison of increasing the power supply
Capacitive compensation for power–factor control
Different types of power capacitors
shunt and series capacitors
Effect of shunt capacitors (Fixed and switched)
Power factor correction
Capacitor allocation
Economic justification
Procedure to determine the best capacitor location.
Micro-controller based Automatic Power Factor Correction System ReportTheory to Practical
This project report represents one of the most effective automatic power factor improvements by using static capacitors which will be controlled by a Microcontroller with very low cost although many existing systems are present which are expensive and difficult to manufacture. In this study, many small rating capacitors are connected in parallel and a reference power factor is set as standard value into the microcontroller IC. Suitable number of static capacitors is automatically connected according to the instruction of the microcontroller to improve the power factor close to unity. Some tricks such as using resistors instead of potential transformer and using one of the most low cost microcontroller IC (ATmega8) which also reduce programming complexity that make it one of the most economical system than any other controlling system.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
2. CONTENTS
BASICS
TARIFF
POWER FACTOR
CAUSES OF LOW POWER FACTOR
DISADVANTAGES OF LOW POWER FACTOR
POWER FACTOR CORRECTION
METHODS OF POWER FACTOR CORRECTION
ADVANTAGES OF POWER FACTOR CORRECTION
3. BASICS
CURRENT(I): “ The flow of electrons through a conductor”.
In amperes (A)
VOLTAGE(V): “The driving force of electrons through a
conductor”. In volts (V)
POWER(P): “The product of voltage and current”.
In watts (W)
RESISTANCE(R): “To oppose the flow of electrons through it”.
In ohms (Ω)
INDUCTANCE(L): “To oppose the sudden changes in current”.
In henrys (H)
CAPACITANCE(C): “To store electric charge”. In farads (F)
4. OHM’S LAW
Statement:
“At a constant temperature
potential difference (V)
between two end points
of the conductor is directly
proportional to the current
(I) flowing through
that conductor”.
5. REACTANCE: The non-resistive component of impedance in an AC circuit
INDUCIVE REACTANCE:
XL = ωL = 2𝝿fL
where ‘ω’ is angular velocity in rad/sec
‘f ’ is frequency in Hz
‘L’ is inductance in H
CAPACITIVE REACTANCE:
Xc= 1/ωC = 1/2𝝿fC
where ‘C’ is capacitance in F
IMPEDENCE: The total resistance of an AC circuit.
For R-L circuit Z = 𝑅2 + 𝑋 𝐿
2
For R-C circuit Z = 𝑅2 + 𝑋 𝐶
2
For R-L-C circuit Z = 𝑅2 + (𝑋 𝐿~𝑋𝑐)2
6. POWER TRIANGLE
IcosΦ P=V*IcosΦ
Φ V Φ Q=V-IsinΦ
IsinΦ I S=V*I
Where IcosΦ is active component of current
IsinΦ is reactive component of current
V&I are circuit voltage and current respectively.
IMPEDENCE TRIANGLE:
S = 𝑃2 + 𝑄2 𝑍 = 𝑅2 + 𝑋2
S Q Z X
ΦΦ
P R
7. ACTIVE POWER(P):
“The power which is actually consumed or utilized in an AC
Circuit is called active power or true power”. In watts(W). or
It is the active component of current (IcosΦ) and circuit voltage (V).
P = V*IcosΦ
REACTIVE POWER(Q):
“The power which flows back and front or reacts upon itself is called as
reactive power or watt less power”. In (VAR). or
It is the reactive component of current (IsinΦ) and circuit voltage (V).
Q = V*IsinΦ
APPARENT POWER(S):
“The product of circuit voltage (V) and circuit current (I) in an AC
circuit is called apparent power”. In (VA).
S = V*I
8. TARIFF
The rate or charge at which electrical energy is supplied to a consumer is
known as tariff.
Which includes cost for generation, investment cost for transmission,
distribution, operation, maintenance and losses. Along with penalty for
consumers at low power factor.
TYPES OF TARIFF
Simple tariff
Flat rate tariff
Block rate tariff
Two port tariff
Maximum demand tariff
Power factor tariff
9. Power factor tariff
kVA maximum demand tariff
kVA = kW/p.f
kWh and kVARh tariff
kVARh = (kW/p.f)*sinθ
Sliding scale or average power factor tariff
Here the average power factor is taken as 0.8 lagging.
If the power facto is less than 0.8 then the consumer will be
penalized.
If the power factor is grater than 0.8 then the consumer will get
discount.
10. TYPES OF LOADS
RESISTIVE LOAD
If the load consist of resistance then that load is a resistive load. Here voltage and
current are in phase so there is no angle between V&I which results unity power
factor. It consumes active power only.
Examples are incandescent lamp and resistance heater.
INDUCTIVE LOAD
If the load consist of resistance and inductance then that load is a inductive load.
Here voltage and current are not in phase so there is an angle between V&I which
results lagging power factor. It consumes both active & reactive power.
Examples are induction motor and transformer.
CAPACITIVE LOAD
If the load consist of resistance and capacitance then that load is a capacitive load.
Here voltage and current are not in phase so there is an angle between V&I which
results leading power factor. It consumes both active power & compensate reactive.
Examples are capacitors and synchronous condenser for power factor correction.
Φ
Φ
I V
V
I
V
I
11. LEADING AND LAGGING
KVAR (LAG)
KVAR (LAG)
KW
KW
INDUCTION
MOTOR
G
L
OVER-EXCITED
SYN. MOTOR
G
L
KVAR (LEAD)KW
KVAR (LEAD)KW
12. POWER FACTOR
“The cosine angle between voltage and current in an AC circuit”.
or
“The ratio of resistance and impedance of an AC circuit”.
or
“The ratio of true power and apparent power”.
For resistive load power factor is unity.
For inductive load power factor is lagging..
For capacitive load power factor is leading.
Φ V
I V
I
Φ
V
I
13. POWER FACTORS OF SOME COMMON LOADS
S.No. TYPE OF LOAD POWER FACTOR
1. Incandescent lamp 1.0
2. Arc lamp 0.3-0.7
3. Neon lamp 0.4-0.5
4. Fluorescent lamp 0.6-0.8
5. Resistance heater 1.0
6. Induction heater 0.85
7. Arc furnace 0.85
8. Induction furnace 0.6
9. Arc welding 0.3-0.4
10. Resistance welding 0.65
11. Induction motor 0.8
14. CAUSES OF LOW POWER FACTOR
Induction motors
Transformers
Arc or induction heating furnaces
Arc lamps and electric discharge lamps
Variable load
15. DISADVANTAGES OF LOW POWER FACTOR
The rating of alternator, transformer and switchgear increased
(KVA).
The size of the conductor increases.
Power loss in the system increases.
Poor voltage regulation.
System efficiency decreases.
Penalty if power factor tariff.
Overall cost increases.
16. POWER FACTOR CORRECTION
Poor power factor is most commonly corrected
with the insertion of a capacitor or a capacitor bank
(a grouping of capacitors) at the desired location to
perform the correction.
The capacitor provides current that Leads the voltage. This combines
with the current associated with the magnetic fields that Lags the
voltage and cancels it out, if sized correctly.
Synchronous machines (either motors or generators) can also supply
leading current, similar to a capacitor, by over-exciting their rotating
field.
The better power factor improvement is depends on proper selection of
SIZE, LOCAION & METHODS
17. SIZE OF CAPACITOR
System
Voltage
Minimum rating of
capacitor bank
3.3 KV ,
6.6KV
75 Kvar
11 KV 200 Kvar
22 KV 400 Kvar
33 KV 600 Kvar
Ic = I1sinФ1 – I2sinФ2
Where
I1sinФ1 is the reactive component before correction
I2sinФ2 is the reactive component before correction
Ic = V/Xc
Xc = 1/ωc
Ω = 2∏f
18. LOCATON OF CAPACITOR
SERIES CONNECTION:
This method of connection is not much common. Even though the voltage
regulation is much high in this method,
It has many disadvantages. One is that because of the series connection, in a short
circuit condition the capacitor should be able to withstand the high current.
The other is that due to the series connection due to the inductivity of the line there
can be a resonance occurring at a certain capacitive value. This will lead to very
low impedance and may cause very high currents to flow through the lines.
PARALLEL CONNECTION:
This is the most popular method of connection. The capacitor is connected in
parallel to the unit.
The voltage rating of the capacitor is usually the same as or a little higher than the
system voltage.
19. METHODS OF POWER FACTOR CORRECTION
1.STATIC CAPACITOR
2.SYNCHRONOUS CONDENSER
3.PHASE ADVANCERSDENSER
20. 1.STATIC CAPACITOR
Power factor can be improved by connecting static capacitor in
parallel with the equipment operating at low power factor.
The capacitor draws leading current from the supply voltage by
90°.
Then it compensates the lagging reactive components of load
current .
Which results improve the power factor.
For more ratings the capacitor banks are used.
In case of 3-phase system the capacitors can be connected either
in star or delta.
Star for industrial and commercial loads.
Delta for distribution system.
21. ADVANTAGES
They have smaller losses (less than 0.5%).
As it has no rotating parts, require little maintenance.
Higher efficiency (above 99%).
Low initial cost.
It can be easily installed as they are light in weight.
It does not require any foundation.
DISADVANTAGES
They have short service life (8-10 years).
Easily damaged due to over voltage.
If they get damaged, their repair is uneconomical.
22. 2.SYNCHRONOUS CONDENSER
An over-excited synchronous machine running on no-load is
known as synchronous condenser.
The over-excited synchronous motor takes leading current and
behaves like a capacitor.
When it is connected across supply, it draws leading current
and partially or fully compensate the lagging reactive
component of load current
Which results improve the power factor.
In this way power factor can be improved to unity even.
Synchronous condensers are usually used where a large
quantity of corrective KVAR is to be required.
23. ADVANTAGES
By varying the field excitation of synchronous machine, the power factor can
be improved to a finer value.
Synchronous condenser can withstand over loads for short duration.
DISADVANTAGES
The cost is higher than the static capacitor of same size (above 500 kVA) .
The maintenance and operation cost is high.
Considerable losses in rotating parts of synchronous condenser.
Lower efficiency compared to static capacitor (nearly 97%).
Produces noise during operation.
Synchronous condenser is not self starting, hence it require an auxiliary
equipment for starting.
There is a chance to fall synchronous condenser out of synchronism which
leads interruption of supply.
24. 3.PHASE ADVANCERS
The phase advancer is a simple AC exciter
It can be mounted on the same shaft of the main motor
It supplies exciting ampere turns to the rotor circuit at slip frequency.
Then it provides flux which results improve the power factor.
If further increase the excitation the power factor goes to lead like over excited
synchronous motor.
ADVANTAGES
The lagging power factor kVAR drawn by the induction motor can be considerably
reduced by supplying leading ampere-turns at slip frequency.
The phase advancer is conveniently employed where the use of synchronous
condenser is not suitable.
DISADANTAGE
They are not economical for motors below 150 KW.
26. ADVANTAGES OF POWER FACTOR CORRECTION
The rating of alternator, transformer and switchgear
decreased (KVA).
The size of the conductor decreased.
Power loss in the system decreased.
Better voltage regulation.
System efficiency increases.
No penalty if power factor tariff.
Overall cost decreases.
