Short Answer

Corona losses can be reduced by designing transmission lines properly. This includes using conductors of larger diameter, increasing spacing between conductors, and using smooth conductor surfaces to reduce electric field intensity.

Other methods include using bundled conductors and corona rings. These techniques help in minimizing ionization of air around the conductor, which reduces power loss, noise, and interference in transmission lines.

Detailed Explanation:

Reduction of corona losses

Corona loss occurs in transmission lines when the surrounding air gets ionized due to high electric field intensity. This leads to power loss, noise, and interference. Therefore, it is important to reduce corona losses for efficient and reliable operation of power systems.

There are several practical methods used to reduce corona losses in transmission lines. These methods mainly focus on reducing the electric field intensity around the conductor.

Use of large diameter conductors

One of the most effective ways to reduce corona loss is by increasing the diameter of the conductor. A larger conductor spreads the electric field over a greater surface area, which reduces its intensity.

When the electric field is reduced below the critical level, ionization of air does not occur easily. As a result, corona formation is minimized.

Use of bundled conductors

Bundled conductors are used in high voltage transmission lines. Instead of using a single conductor per phase, two or more conductors are grouped together.

This arrangement increases the effective diameter of the conductor and reduces electric field intensity. It also improves transmission efficiency and reduces corona loss.

Increase in spacing between conductors

Increasing the distance between conductors helps in reducing the electric field strength. When conductors are placed far apart, the electric field around each conductor becomes weaker.

This reduces the chances of air ionization and hence decreases corona losses.

Use of smooth conductor surface

Conductors with rough or uneven surfaces have higher electric field concentration at sharp points. These points become starting locations for corona discharge.

Using smooth and polished conductors reduces such irregularities and helps in minimizing corona formation.

Use of corona rings

Corona rings are metal rings fitted at the ends of insulators and high voltage equipment. They help in distributing the electric field evenly around the conductor.

By reducing sharp edges and field concentration, corona rings prevent ionization of air and reduce corona losses.

Proper selection of operating voltage

Operating the transmission line at a voltage below the critical disruptive voltage reduces corona effect. Proper design ensures that the system operates safely without excessive electric field strength.

Effect of weather conditions

Although weather cannot be controlled, proper design can reduce its impact. For example, during rain or fog, corona increases due to moisture in air. Using suitable conductor design helps reduce corona even in such conditions.

Conclusion

Corona losses can be reduced by proper design and maintenance of transmission lines. Methods such as using large diameter conductors, bundled conductors, smooth surfaces, and corona rings are very effective. Reducing corona losses improves efficiency, reduces noise and interference, and increases the life of electrical equipment.