Something you should Know about Lightning Arrester
We should not be unfamiliar with lightning arresters, but we don't often see them. So today we talk about the role of lightning arresters.
The function of lightning arrester
A lightning arrester is equipment to protect substation equipment from lightning shock waves. When the lightning impulse wave introduced into the substation along the line exceeds the protection level of the lightning arrester, the lightning arrester first discharges, and safely introduces the lightning current to the earth through a good conductor. The grounding device is used to limit the lightning voltage amplitude below the lightning impulse level of the protected equipment so that the electrical equipment is protected.
- When the instantaneous pulse voltage occurs in the power grid due to a lightning strike, the lightning arrester will be turned on within nanoseconds.
- The lightning arrester is turned on within nanoseconds, which will short circuit the pulse voltage to the ground and discharge, and then return to the high resistance state, so as not to affect the power supply of user equipment.
Several indexes of power arrester
- Volt's second characteristic: refers to the corresponding relationship between voltage and time.
- Power frequency freewheeling: refers to the power frequency short-circuit grounding current flowing through the lightning voltage or overvoltage discharge, but the power frequency voltage still acts on the lightning arrester.
- Self-recovery ability of insulation strength: the relationship between the insulation strength of electrical equipment and time, that is, the speed of recovery to the original insulation strength.
- Rated voltage of lightning arrester: the maximum power frequency voltage that can be borne by the gap after the first zero crossing of power frequency freewheeling and will not cause arc ignition, also known as arc voltage.