What is Corona Effect in Transmission Line?

Q: How can corona loss in the transmission lines be reduced?

Corona's effect can be reduced for the following reasons. Sr. No. How Reducing Corona Effect #1. Increase Conductor Diameter #2. Increase Spacing Between Conductor #3. Reduce Operating Voltage #4. Using Corona Ring #5. Using Bundle Conductor

Q: What are the advantages of corona loss?

The benefits of Corona Fact are as follows: Due to the corona throughout the conductor, the air around the conductor becomes a conductor that increases the diameter of the conductor virtually. This virtual increase in conductor diameter reduces the maximum potential pulses or the maximum electrostatic stress.

Hello friends, in today’s article we will talk about what is Corona effect and how it can be reduced, and what are the non-benefits of the Corona effect.

What is Corona Effect?

In the transmission line when more voltage is sent from one place to another. This side of the conductor produces a velvet-colored light. The effect of this light is known as the corona effect.

Why Corona Effect is Created:

As we know that electrons flow in any conductor.When a current moves from one place to another, a magnetic field is created around it. This magnetic field causes a problem of a potential gradient. This causes a corona to form.

What is a Potential Gradient?

This is very easy to understand.

Example: If there is a wire in which 400 KV voltage flows then we know that passing voltage inside the wire becomes an electrical magnetic field on its side. Due to this electrical magnetic field, a few voltages are generated on this side of the wire.

Due to the presence of more magnetic lines in the area of 1 cm of wire, more voltage flows in the air. In the same way, in the area of 2 cm from the wire, the magnetic line decreases a little and this also reduces the flow of voltages. This is called Potential Gradient. Since the transmission line is mounted at a height, there is always air on this side of the conductor.

When current passes through this wire, the air on this side of the wire acts as a dielectric medium.

The dielectric medium of air varies according to temperature. The dielectric of air is 30 KV/Cm at a normal temperature.

This means that 1 cm of air passing through 30 KV or more current also passes through the air. This is called an air breakdown. Due to the breakdown in the air, noise can be heard in the high-voltage line. Due to the breakdown in the air, along with the noise, vibration is also generated in the conductor. This is why the corona effect occurs.

Suggested Read: Difference Between Transmission Line And Distribution Line

The Reason for the Corona Effect:

There are many causes of the corona effect, some of which are as follows:

Sr. No.	Reason for the Corona Effect
#1.	Atmospheric Conditions
#2.	Line Voltage
#3.	Nature of Conductor Surface
#4.	Effect on Frequency
#5.	Effect of Air Conductivity

#1. Atmospheric Conditions:

Corona is most likely to occur in the rainy season as the rainy season humidity is higher only in the air and therefore the current flows easily in the air.

#2. Line Voltage:

The corona effect is also higher as the line voltage is higher. If the voltages of the transmission line are higher then the magnetic field around it will be more. This also increases the effect of the corona.

#3. Nature of Conductor Surface:

The corona effect depends on which gauge the conductor is made of. If the shape of the conductor is made round, the effect of the corona is reduced.

That is why we use only the ACSR conductor in the transmission line.

#4. Effect on Frequency:

Even if the frequency is high, the effect of the corona is more.

#5. Effect of Air Conductivity:

The Corona effect also depends on the conductivity of the air. If the conductivity of air is high then the corona effect is also high.

Suggested Read: Advantages of High Transmission Voltage

How to Reduce Corona Effect on Transmission Lines?

Corona’s effect can be reduced for the following reasons.

Sr. No.	How Reducing Corona Effect
#1.	Increase Conductor Diameter
#2.	Increase Spacing Between Conductor
#3.	Reduce Operating Voltage
#4.	Using Corona Ring
#5.	Using Bundle Conductor

#1. Increase Conductor Diameter:

Increasing the thickness of the conductor can reduce the corona to some extent.

#2. Increase Spacing Between Conductor:

If we have two different conductors in which the voltage is flowing. The corona can also be reduced by increasing the distance between those two wires.

#3. Reduce Operating Voltage:

We can also reduce the corona by lowering the voltage, because if we reduce the voltage then it will be difficult for current to flow in the air.

#4. Using Corona Ring:

You can also reduce the corona effect by using a corona ring. This ring is also called anti corona ring.

#5. Using Bundle Conductor:

Where we need more power, we distribute the power using bundled conductors, this method is used a lot.

Suggested Read: Types of Losses in a Transformer | Efficiency of Transformer

The Disadvantage of the Corona Effect:

The disadvantages of the Corona Effect are as follows:

Loss of Power.
Produces Ozone Gas.
Third Harmonic.

#1. Loss of Power:

Loss of power due to the corona effect also reduces the efficiency of the transmission line.

#2. Produces Ozone Gas:

When it is a corona, it produces ozone gas around it. This ozone gas acts as an acid. This gas causes corrosion on the conductor which shortens the life of the conductor.

#3. Third Harmonic:

The corona produces the third harmonic, causing the corona to reduce the stability of the system.

Most Commonly Asked Questions:

How corona is formed in the transmission line?

The corona is found in every transmission line. Subject to certain conditions, a localized electric field close to energetic components and conductors can generate small electric charges or corona. Which causes the surrounding air molecules to ionize or change a little too much in the electric charge.

What is corona loss in transmission?

The corona appears in the transmission line when the surface voltage on the line conductor reaches a strong breakdown. The corona produces heat and blue light. It is a loss of dissipation of energy and power in space. Such damage is known as coronal damage.

Suggested Read: What is an Electrical Transducer? | Types of Electrical Transducer

How can corona loss in the transmission lines be reduced?