The principle of lightning arrester

Lightning arrester is a device that protects equipment in substations from lightning shock waves. When the lightning shock wave entering the substation along the line exceeds the protection level of the arrester, the arrester first discharges, and the lightning current is safely introduced into the ground through a good conductor. The grounding device is used to limit the amplitude of the lightning voltage below the lightning strike level of the protected equipment. Electrical equipment is protected.

The arrester can be divided according to its development sequence: protection gap-is the simplest form of lightning arrester; tubular obo arrester-is also a protection gap, but it can extinguish the arc after discharge; valve-type arrester-is a single The discharge gap is divided into many short series gaps, at the same time increase the nonlinear resistance, improve the protection performance; magnetic blowing arrester-the use of magnetic blowing spark gap, improve arc extinction ability, but also has the ability to limit internal overvoltage; oxidation Zinc lightning arrester-using the ideal volt-ampere characteristics of zinc oxide valves (non-linear extremely high, that is, low resistance characteristics at high currents, limiting the voltage on the arrester, showing high resistance characteristics at normal power frequency voltage), It has the advantages of no gap and no residual current and low residual voltage. It can also limit the internal overvoltage and is widely used.