Why Reactive Power is Necessary ? | The Best Explanation | What is Reactive Power ?

Summary

This educational YouTube video from 'Build the Basics' explores the role of reactive power in electrical systems. It clarifies misconceptions about reactive power being useless, emphasizing its necessity for creating magnetic and electric fields essential for the operation of motors, transformers, and other equipment. The video explains that while reactive power does contribute to energy losses in transmission lines, it is crucial for the functionality of many electrical devices. It also discusses the importance of reactive power compensation to balance consumption and production, thereby reducing line losses and improving voltage profiles in power systems.

Takeaways

• 🔌 There are three components of power: active power, reactive power, and apparent power, forming a power triangle.
• 💡 Active power is the actual power consumed by the load and is considered useful, while reactive power is often misunderstood as useless.
• 🏭 Power transmission involves losses due to line resistance and additional currents caused by the reactive nature of transmission lines.
• 🔋 Reactive power is essential for creating magnetic fields and electric fields, which are necessary for the operation of many electrical devices.
• 🏗️ Equipment like motors and transformers rely on reactive power to function properly, as it helps in establishing magnetic fields and inducing voltage.
• 🔧 Reactive loads can be either inductive, like motors and transformers, or capacitive, like capacitors and line capacitance.
• 🌐 Reactive power is not useless; it is necessary for the proper functioning of electrical systems and equipment.
• ⚙️ Reactive power compensation is crucial to balance reactive power consumption and production in a power system.
• 🔄 Reactive power control helps reduce losses and voltage drop in transmission lines by generating reactive power at the point of need.
• 📈 Shunt inductors and capacitors are used to manage voltage profiles and minimize effects like the Ferranti effect in power transmission.

Q & A

What are the three components of power?

The three components of power are active power, reactive power, and apparent power. They form a power triangle together.

What is active power?

Active power is the actual power consumed by the load and is considered the useful power.

What is reactive power?

Reactive power is the power that is associated with the reactive nature of the transmission lines and does not directly contribute to the work done by the load.

What is the role of reactive power in power transmission?

Reactive power causes additional current flow in the transmission lines, which can lead to increased losses and voltage drop.

Why is reactive power necessary in electrical systems?

Reactive power is necessary to produce magnetic fields and electric fields, which are essential for the operation of many electrical machines and equipment such as motors and transformers.

What are the two types of loads in electrical systems?

The two types of loads are resistive loads, which consume electrical energy, and reactive loads, which store and feed back electrical energy.

What are some examples of resistive loads?

Examples of resistive loads include heaters, lightbulbs, and most domestic appliances like fans, heaters, or refrigerators.

What are the two types of reactive loads?

The two types of reactive loads are inductive loads, such as motors and transformers, and capacitive loads, like capacitors and line capacitance.

Why is reactive power control important in power systems?

Reactive power control is important to balance the reactive power consumption and production in the power system, which helps reduce losses and voltage drop in transmission lines.

How can reactive power be compensated in power systems?

Reactive power can be compensated by generating reactive power at the places of its requirement using capacitors or synchronous machines, thus avoiding its transmission through lines.

What is the Ferranti effect and how is it related to reactive power?

The Ferranti effect is a phenomenon where the receiving end voltage of a transmission line increases, particularly in lightly loaded conditions. Reactive power control using shunt inductors or capacitors can be used to minimize the Ferranti effect and improve voltage profiles.

Outlines

00:00

🔌 Understanding Reactive Power

This paragraph introduces the concept of reactive power and its role in electrical systems. It explains that reactive power, along with active power, forms the total apparent power. The presenter clarifies that while active power is the actual power consumed, reactive power is often misunderstood as useless. The script sets the stage for a deeper discussion on reactive power by highlighting its importance in power transmission and distribution. It mentions that power losses occur due to line resistance and that reactive power contributes to additional losses and voltage drop. The paragraph ends with an invitation to learn more about reactive power and an encouragement to subscribe to the YouTube channel for further insights.

05:03

🌐 The Utility of Reactive Power

In this paragraph, the speaker asserts that reactive power is not useless but is, in fact, essential for various electrical phenomena, such as the creation of magnetic and electric fields. It is highlighted that most electrical equipment, including generators, transformers, and motors, relies on reactive power to function properly. The paragraph explains that reactive power is necessary for establishing magnetic fields that are crucial for the operation of these devices. Additionally, it touches on the use of capacitors to compensate for reactive power and control voltage in the power system. The speaker concludes by emphasizing the importance of reactive power compensation to balance consumption and production, thereby reducing losses and voltage drop in transmission lines. The video ends with a call to action for viewers to subscribe for more educational content.

Keywords

💡Active Power

Active power is the actual power consumed by a load to perform useful work, such as lighting, heating, or running appliances. In the video, it is described as 'useful power' in contrast to reactive power, which is often considered less direct in its application. Active power is a critical component of the total power in a system and is what most devices consume.

💡Reactive Power

Reactive power refers to the portion of electricity that does not perform useful work but is necessary for maintaining the voltage levels needed to drive active power through transmission lines. The video emphasizes that while reactive power is often seen as 'useless,' it is essential for producing magnetic and electric fields in systems like motors and transformers. Reactive power helps in voltage regulation and maintaining the functioning of power system components.

💡Apparent Power

Apparent power is the combination of active power and reactive power. It represents the total power generated by a system, combining the useful and non-useful (or reactive) portions of power. The video explains that apparent power is visualized through a power triangle, indicating the relationships between active and reactive power in electrical systems.

💡Power Triangle

The power triangle is a graphical representation used to visualize the relationship between active power, reactive power, and apparent power. The video uses this concept to illustrate how these types of power are interconnected. The active power is represented on one side, the reactive power on another, and the apparent power forms the hypotenuse of the triangle.

💡I²R Losses

I²R losses refer to power losses that occur due to the internal resistance of transmission lines when current flows through them. These losses are caused by the resistance (R) and the square of the current (I), leading to heat generation. The video discusses how reactive power increases the current flowing through transmission lines, thereby amplifying these losses.

💡Resistive Loads

Resistive loads consume electrical energy and convert it into heat or light. Examples include heaters, light bulbs, and domestic appliances like fans and refrigerators. The video contrasts resistive loads with reactive loads, explaining how they play a significant role in electrical systems by consuming active power.

💡Reactive Loads

Reactive loads temporarily store and then release electrical energy without consuming it. These loads, such as motors under low load, transformers, and line inductance, require reactive power for their operation. The video highlights the importance of reactive loads in electrical systems, showing how they demand reactive power for functions like maintaining magnetic fields.

💡Inductive Load

Inductive loads store energy in the form of magnetic fields and require reactive power to maintain those fields. Examples from the video include motors and transformers, which depend on reactive power to generate magnetic fields necessary for their operation. Inductive loads are key in many devices that operate on electromagnetic principles.

💡Capacitive Load

Capacitive loads store energy in electric fields and also require reactive power. Examples in the video include the capacitance of transmission lines and compensation capacitors in power systems. Capacitive loads are discussed as important in balancing the reactive power in a system, especially for voltage control.

💡Reactive Power Compensation

Reactive power compensation is the process of balancing the consumption and production of reactive power in an electrical system. The video explains that this can help reduce transmission losses and voltage drops. Techniques like installing shunt capacitors or inductors are used to generate reactive power locally, avoiding unnecessary transmission over long distances.

Highlights

Reactive power is not useless; it is essential for electrical energy consumption.

Active power is the actual power consumed by the load, while reactive power is often misunderstood.

Power transmission involves losses due to line resistance and reactive power currents.

Reactive power is necessary for the creation of magnetic fields in electrical equipment.

Generators and transformers rely on reactive power to function properly.

Motors require reactive power to establish and maintain a rotating magnetic field.

Transformers need reactive power to induce voltage in their secondary coils.

Reactive power is produced by lightly loaded transmission lines and synchronous machines.

Capacitors store electrical energy and help compensate for reactive power.

Reactive power control is used to reduce line losses and voltage drop.

Shunt inductors and capacitors are used to manage voltage profiles in the power system.

Reactive power is crucial for the operation of most power system equipment and consumer loads.

Reactive power compensation balances consumption and production in the power system.

Generating reactive power at the point of requirement avoids unnecessary transmission losses.

Reactive power is fundamental for electromagnetic induction in machines and equipment.

Understanding reactive power is key to optimizing power system performance.

Transcripts

you

[Music]

dear students welcome to build the

basics YouTube channel today let me

answer this basic question whether

reactive power is useful or useless

power let's go into the details

we all have learnt from the books that

there are three components of power so

number one is active power and reactive

power and together they form apparent

power so and they if they form a power

triangle together so we also have been

told that the active power is these the

actual power consumed by the load and it

is only the useful power and the rest of

the power is useless so but in this

video I want to highlight whether the

other component of the power that is the

reactive power is really useless or not

now let's talk about basics of power

transmission as you know the generating

stations generate electric power and

this power is transmitted to load

centers using transmission lines and to

the customers through power distribution

network so in this process the power

generated by the generating station is

not fully consumed by the loads because

there is some power loss resulted in the

transmission and distribution networks

mainly due to the line internal

resistance and also the current flowing

through the transmission lines so this

is called as I square R losses actually

you cannot avoid this current flow due

to the power demand in the load centers

because current is required in the load

centers but the problem is on top of the

normal current there will be some

additional currents due to the reactive

nature of the transmission lines and

this this additional there therefore the

additional loss also saw also results so

this will further increase the losses in

the transmission lines and also voltage

drop across the line basically this is

the drawback of additional current due

to the reactive power

then what is the advantage of reactive

power can't we avoid is current in the

transmission lines due to reactive power

the answers to these questions are

explained in this video first of all

don't forget to subscribe to build the

basics YouTube channel and click on the

bell button towards such interesting

videos in the future we need to learn

some basics first before getting into

the details of reactive power there are

basically two types of loads so they are

resistive load and reactive loads so the

resistive loads consumes electrical

energy the examples of resistive loads

are the heaters lightbulbs and also most

domestic appliances like fans or heaters

or refrigerators but under load because

if they're if they are under load or

fully loaded then they're predominantly

resistive remember under no load

condition the situation is different

we will which I will explain later the

second type of load is reactive loads

the reactive loads or they store

electrical energy temporarily and they

feed it back to the source so they

basically they don't consume any

electrical energy so reactive loads are

two types first one is inductive type

and the capacitor type examples of

reactive loads are motor on low load or

no load condition because it mainly acts

like a reactive load it consumes

reactive power and also transformers and

also react reactors in the substations

and line inductance of transmission

lines also line capacitance of the the

other type of reactor load is capacitive

that then line capacitance of the

transmission line and compensation

capacitors of the power system and

Composition converters also also

reactive loads so remember both react

react reactive and resistive loads draw

current when constant voltage or current

is applied but in real world every load

is mix of resistive and reactive loads

you cannot find only this to load our

only reactive loads they are always

combination of these two now coming back

to the basic question whether reactive

power is useful power are useless power

my answer is the reactive power is is

really useful for word it is not useless

in fact it is very useful and essential

in our daily electrical energy

consumption process reactive power is

needed to produce two important

electrical phenomena called as magnetic

field and electric fields so if you if

you see most of our machines and

equipment work on electromagnetic

induction principle in generators and

transformers the voltages induced due to

magnetic fields and in motors torque is

produced due to magnetic fields

therefore most of the equipment consumed

the reactive power the motor needs to

establish and maintain rotating magnetic

field to rotate the rotor thereby

driving the mechanical motion the rotor

magnetic field of the motor is

established by taking reactive power

from the source

similarly the transformer also needs

reactive power to generate magnetic

field in the primary coil of the

transformer and induce voltage in the

secondary coil

therefore if the reactive power supply

is not adequate the motor will not

rotate and transformer will not

transform voltages and most of the

passive filters do not work in the power

system so now let's talk about other

equipment that produce reactive power

the reactive power is produced by

lightly loaded transmission lines

because they are capacitive nature or

synchronous machines or static

capacitors etc they

Kelly capacitors store electrical energy

in the form of electric field so we use

reactive power again one reactive power

again is another reactive power because

to compensate lacking reactive power or

reactive power consumed by the inductive

nature of the load we use capacitors to

composite that reactive power because

capacitors basically produce reactive

power so by by controlling this reactive

power we can also control the voltage in

the power system for example we use the

shunt inductors to minimize the voltage

rise due to Ferranti effect you know

Ferranti effect and epoch basically the

receiving end voltage of the

transmission line will increase due to

the lightly low in particularly in

lightly loaded condition so to

compensate the minimizer Ferranti effect

we use shunt inductors to minimize the

voltage voltage rise and also we use

sometimes shunt capacitors to improve

the voltage profile at the load centers

therefore without reactive power most of

the power system equipment and consumer

loads will not work so reactive power

the conclusion is reactive power is very

useful in power system however there is

a need for reactive power compensation

in the power system to balance the

reactive power consumption and

production so so instead of transmitting

the reactive power from generating

stations to the load centers because it

results in additional losses and voltage

drop what you can do is generate

reactive power at the places of its

requirement so this avoids transmitting

through the lines and this is called as

reactive power control so this reactive

power control basically helps in

reducing the losses in the lines due to

the additional current flowing through

the lines and also voltage drop as I

mentioned before so thank you very much

and this is about reactive power

I hope the V the video is helpful for

you to understand the basics of reactive

power so subscribe to will build the

basics YouTube channel and

wait for more videos in future thank you

you

[Music]

you