Lightning arrester is the main protection electric equipment that uses limitative thunder overvoltage. Circuitry of distribution of built on stilts uses lightning arrester to undertake Lei Bao is protected preventing more, lightning arrester ground connection also is called overvoltage to protect ground connection.
Thunder overvoltage and in-house overvoltage are right circuitry of the distribution in moving and the harm that equipment causes, pure support raises equipment insulation level to bear these two kinds of overvoltage, not only be unreasonable economically, and also often be impossible on the technology. Active method is the electric equipment that uses special limitation overvoltage, equipment voltage order and degree is higher, the economic benefits that reduces insulation level place to bring is more remarkable. overvoltage limitation is on a reasonable level, choose corresponding equipment insulation level by this next, make the overvoltage of power system and insulation reasonable cooperate.
Lightning arrester is a kind of protection equipment that can release overvoltage energy to restrict overvoltage amplitude. Lightning arrester should be installed be being protected equipment is near, bond between its terminal. Overvoltage passes lightning arrester by circuit, when its the value reachs action of the lightning arrester when voltage of lightning arrester movement, decide overvoltage limitation the level to some (call protective level) . Later, lightning arrester restores off-state quickly again, power system returns to normal condition.
The protective character of lightning arrester is to be protected the foundation of equipment co-ordination of insulation, the protection that improves lightning arrester is characteristic, can rise to be protected the sex of moving on the safe side of equipment, also can reduce the insulation level of equipment, reduce cost thereby.
Lightning arrester should accord with following and main demand:
(1) can bear for a long time systematic abidance runs voltage, and but short when the temporary overvoltage that bears to often appear possibly;
(2) fall in overvoltage action, its protect a level to satisfy the requirement of insulation level;
(3) can bear the energy of the generation below overvoltage action;
(4) after overvoltage goes can return to normal quickly working status.
By crust material cent is porcelain carapace model, organic carapace, iron carapace.
By operating ambient conditions cent is normal use condition highland model, defilement, tropics.
By utility cent is general-purpose with special application model, general-purpose apply to distribution station, power station, low-pressure electrified wire netting, rotate the overvoltage protection of electric machinery, electric railway, special application apply to block wave implement, the overvoltage protection that capacitor group, cable protects a layer.
By the material of working component cent is lightning arrester of oxide of lightning arrester of type of carborundum a powerful person, metal. Lightning arrester of type of carborundum a powerful person can be divided again according to its structure blow lightning arrester of type of a powerful person for lightning arrester of type of average a powerful person and magnetism, metallic oxide lightning arrester is very close to each other according to structural cent lightning arrester of oxide of unoccupied place metal, have lightning arrester of oxide of metal of series connection clearance, have lightning arrester of oxide of shunt-wound clearance metal. Metallic oxide lightning arrester calls very close to each other unoccupied place lightning arrester again, its a powerful person piece give priority to with zinc oxide, and mix into wait for metallic oxide with antimonial, bismuth, manganese, smash mix even hind, become via high temperature agglomeration.
The utility of a powerful person that separates by the material of working component lightning arrester and metallic oxide lightning arrester is:
1) a powerful person lightning arrester: Commonly used the protection preventing thunder at the switch on head of terminal of distribution transformer cable, column and equipment, also can use as transformer station is electric the protection preventing thunder of equipment prevents thunder protection to wait with what place electric machinery;
2) metallic oxide lightning arrester: Have good shed capacity and the capacity that control overvoltage, it is the lightning arrester with a kind of good performance. Apply to distribution transformer watch of side electric energy and communication branch make the protection that prevent thunder.
The electric function of lightning arrester
(1) protection. Restrict overvoltage, protection is electric equipment insulation is unapt get overvoltage and attaint.
(2) destroy arc sex. Overvoltage causes breakdown of clearance of scintilla of lightning arrester interior, and it is normal to scintilla clearance can extinguish electric arc quickly and do not break power system power supply.
(3) shed ability. In course of lightning arrester start, the likelihood is able to bear or endure suffer through all sorts of its electric current do not cause damage.
The main and electric parameter of lightning arrester
(1) destroy arc voltage: In assure to destroy arc (cut off labour frequency follow on current) below the condition, allow the tension of highest labour frequency that is increased on lightning arrester.
(2) rated voltage: Point to the labour frequency voltage that lightning arrester works for a long time normally, its are rated voltage and the electrified wire netting that furnish ground nods are rated voltage is consistent.
(3) labour frequency spark voltage: Of lightning arrester shed ability finite, the condition that allows in-house overvoltage commonly not movement. But, with times overvoltage energy bigger, lightning arrester may cause explosion when producing in-house overvoltage, stipulated for this this voltage is numeric, general provision is not less than a system the 3 ～ of the biggest phase voltage 3.5 times.
(4) shed a capacity: Of lightning arrester shedding a capacity is to show a powerful person piece be able to bear or endure the staying power that gets follow on current of frequency of thunder electric current, labour and operation impulse current.
(5) pound spark voltage: Show time is 1.5 ～ wave of standard of 40 μ S discharges beforehand, time is 1.5 ～ the concussion spark voltage of 20 μ S.
(6) residual voltage: The residual voltage of lightning arrester is when showing lightning current passes lightning arrester, in lightning arrester the voltage drop of two end, resistor of sex of a powerful person of depress of lightning arrester incomplete, specification piece connect it is good to shed ability to heal.
(7) protective comparing: The residual voltage that points to lightning arrester and destroy arc voltage (peak value) than, this ratio jumps over the function of small specification lightning arrester to had healed.
The basic technology parameter of lightning arrester chooses according to labour frequency overvoltage, contain the lightning arrester of series connection clearance, its clearance destroys arc voltage must not is worth under its, without the metallic oxide lightning arrester of clearance, its are rated voltage (or call its the movement initiative voltage) and run voltage to also decide from this continuously. When these parameter choices that are like lightning arrester are undeserved, the attaint rate of lightning arrester can increase considerably.
Lightning arrester of oxide of metal of distribution of 10kV compound coat
Lightning arrester of oxide of metal of distribution of 10kV compound coat (belt disengage apparatus)
Typical power station with distribution lightning arrester electric character
Install sketch map
