Surge arrester is an insulating device used to protect system from overvoltage. Zinc oxide surge arrester is a kind of overvoltage protection device which has been widely used in power system. Zinc oxide arrester by porcelain or glass insulator, valve, fixed bolts and other components. In recent years, ZnO arrester is mainly used in power system, which can protect the system from overvoltage.
Structure
Zinc oxide arrester by the porcelain sleeve, valve, fixed bolts and other components. Main structure:
1. The ceramic insulator materials are glass, alumina and zinc oxide, and the zinc oxide lightning arrester composed of the ceramic insulator has excellent insulation performance, small volume and light weight, and is a widely used protective appliance in the power system.
2. Valve disc: consisting of one or more regularly shaped metal films, including zinc oxide, metal foil or glass foil. The lightning arrester can be used to protect electrical equipment from overvoltage in power system.
3. The fixing bolts are mainly used for connecting and supporting between the fixing valve piece and the valve seat.
Principle of operation
Zinc oxide lightning arrester is composed of valve piece, porcelain insulator (or glass insulator), fixing bolt and porcelain sleeve. The lightning impulse current is limited by the over-voltage absorbing element of the valve piece. The effect process is as follows: when the lightning wave invades, the lightning arrester immediately absorbs energy and produces a large power frequency current through the valve piece; if the lightning wave continues to invade and the valve piece can still keep good insulation state, the residual charge in the lightning arrester is discharged because the residual voltage of the valve piece falls below the rated voltage value.
Working Principle of Surge Arrester: When the Surge Arrester generates power frequency current, its discharge capacity is related to the shock absorbing capacity of the Surge Arrester and the residual voltage of the valve slice; when the overvoltage is a certain rated value, the Surge Arrester will discharge a large amount of charge through the varistor on the valve slice without breakdown.
Characteristics
(1) Small size, light weight and no noise.
(2) Strong ability to withstand over-voltage, and good ability to withstand power frequency voltage and impulse current.
(3) It shall have good electrical and thermal performance and small and stable temperature coefficient.
(4) no residual voltage, long service life and reliable use.
(5) High cost performance and easy manufacture.
As an over-voltage protection device in power system, ZnO arrester plays an important role in the safe operation of electrical equipment and power grid. With the development of electric power in our country, the application of MOA will be more and more extensive. In the process of application, we should strengthen the analysis of the performance of the arrester, improve the installation technology and maintenance quality, avoid the equipment damage failure due to technical reasons, and ensure the safe and reliable operation of electrical equipment and power grid.
Post time: Feb-22-2023