Starting from the transmission system side, which is the first equipment seen in the substation?

March 12, 2023

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capacitor bank
current transformer
circuit breaker
lightning arrester

Answer: 4. lightning arrester

Explanation:

What is Lightning Arrester?

A lightning arrester is a device that is used to protect electrical equipment from damage caused by high-voltage transient surges or lightning strikes. Lightning strikes can cause massive electrical surges that can damage or destroy electrical equipment, and lightning arresters are designed to divert these surges safely to the ground.

Lightning arresters are designed to protect equipment at substations against traveling waves. Traveling waves are high-frequency electrical disturbances that can propagate along power lines, and they can cause significant damage to electrical equipment if they are not properly controlled. Lightning arresters are designed to absorb these waves and divert them safely to the ground, thereby protecting the equipment.

In the event of a lightning strike or other high-voltage transient surge, a lightning arrester diverts the abnormally high voltage safely to the ground. This prevents the surge from damaging or destroying the equipment, while also ensuring that the continuity of supply is not affected. Lightning arresters are typically installed in parallel with the equipment to be protected, and they are connected between the line and earth.

Lightning arresters are typically connected near the transformer at the substation. This is because transformers are one of the most expensive and critical pieces of equipment in the substation, and they are particularly vulnerable to damage from lightning strikes and other high-voltage surges. By installing lightning arresters near the transformer, the equipment can be protected from these surges and ensure that the substation continues to operate safely and reliably.

Types of Lightning Arrester:

What is Rod gap arrester?

The basic design of a rod gap arrester consists of two metal rods separated by a small air gap. One end of the arrester is connected to the line, which carries the electrical power, while the other end is connected to the ground. The air gap provides a path of low resistance for the high voltage surge to pass through, diverting it away from the equipment and dissipating the energy harmlessly into the ground.

The rod gap arrester works on the principle of the spark gap. When a high voltage surge occurs, it ionizes the air in the gap, creating a conductive path for the surge to follow. This allows the surge to be safely directed away from the equipment and into the ground.

What is Horn Gap Arrester?

A horn gap arrester is a type of lightning arrester that protects electrical equipment and transmission lines from high voltage surges, including those caused by lightning strikes. The arrester consists of two horn-shaped metal pieces separated by a small air gap, which are connected in a shunt between each conductor and earth.

The distance between the two electrodes, or horns, is set such that normal voltage between the line and earth is insufficient to jump the gap. This means that during normal operating conditions, the arrester remains in a non-conducting state and does not affect the flow of electrical current through the system.

However, when an abnormal high voltage surge occurs, such as a lightning strike, the voltage between the line and earth increases beyond the normal operating range, and the gap between the horns breaks down. This creates a conductive path for the surge to follow, which diverts it away from the equipment and into the ground, protecting the equipment from damage.

The horns on the arrester provide a sharp point, which helps to ionize the air and create a conductive path for the surge to follow. This allows the surge to be safely directed away from the equipment and into the ground.