What is a Nickle (direct lightning)?

• A direct strike is a phenomenon in which lightning strikes a structure, equipment, power line, etc. directly .

• In this case, voltages exceeding approximately 20 kV and overcurrents exceeding several kA to 300 kA may occur, which may cause physical damage to structures or equipment, rupture, fire, hardware damage , etc.

Other bibliography (bibliography type)

Depending on the cause of occurrence, surges are classified as follows:

1. Lightning surge

• Direct lightning : Same as the nick lightning (direct lightning) described above.

• Indirect lightning : A phenomenon in which lightning strikes a power transmission line, communication line, etc. and a surge is transmitted through the line. This occurs most frequently and causes great damage as large amounts of energy of 6,000 V or more are generated.

• Induced lightning : A surge induced through conductors such as buried power lines, communication lines, and metal pipes when lightning strikes the nearby ground . The ground potential rises sharply, causing high voltage and current to flow in.

• Lightning discharge : A phenomenon in which an electric charge induced by a discharge between clouds and the ground, within a cloud, or between clouds flows to power lines, metal objects, or the ground, damaging equipment.

2. Opening and closing surge

• Switching surge is a surge that occurs during electrical switching operations such as switching large-capacity equipment, switching inductive loads, and starting .

• It is divided into external opening and internal opening.

3. System failure

• System fault surges are surges that occur due to ground faults, momentary power outages, and other faults in the power system .

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• Electrostatic discharge : A surge caused by electrostatic discharge.

• Nuclear explosions, electromagnetic pulses : Also includes electromagnetic pulses (EMPs) from high-altitude nuclear explosions or electromagnetic pulses.

Key Features and Impacts of Surge

• A surge is an AC voltage condition that increases by 5 to 20% above the normal voltage, or a momentary voltage/current spike lasting from nanoseconds to milliseconds .

• It can be caused by various reasons such as lightning, opening and closing, and electrostatic discharge, and can cause damage such as electronic device malfunction, damage, and fire .

Note: Surge protection measures

• A variety of protective devices are used, including surge protective devices (SPDs) , lightning rods , and grounding systems .

Types of lightning surges