Power lightning protection design There are four main t […]
Power lightning protection design
There are four main types of lightning strikes:
The direct lightning strike contains enormous energy, and the lightning current with a peak voltage of up to 5000kV enters the ground and has great destructive power. There are three effects that can be caused:
(1) The huge current is flowing down in a few microseconds, so that the ground potential is quickly picked up, causing a counterattack accident and endangering personal and equipment safety.
(2) The lightning current generates a strong electromagnetic wave, which induces a very high pulse voltage on the power line and the signal line.
(3) Thunder current flows through electrical equipment to generate extremely high heat, causing fire or explosion accidents.
The lightning strikes in the distance or the extremely high voltage generated by the electromagnetic induction are transmitted from the outdoor power supply line and the communication line to the electrical equipment in the interior of the building.
Frequent discharges between clouds produce powerful electromagnetic waves that cause common mode and differential mode interference, affecting the operation of electrical equipment.
4. Switching overvoltage
Inductive and capacitive loads in the power supply system can be opened or disconnected, short-circuited to the ground, short-circuited in the power supply line, etc., and high-voltage pulses can be generated on the power line. The pulse voltage can reach 3 to 5 times of the normal voltage, which can seriously damage the equipment. . The damage effect is similar to lightning strikes.