The relationship between the structure and performance of composite jacketed zinc oxide arresters was studied. Through comparative testing of the electrical, physical and mechanical properties of several typical internal structure arresters, the differences in relevant performance of each structure were obtained, and experimental basis was provided for the optimized design of composite jacketed zinc oxide arresters.
The components of zinc oxide arrester. Zinc oxide arrester is composed of multiple sections according to the voltage. 35-110K/zinc oxide arrester is a single section, 220K/zinc oxide arrester is composed of two sections, and 500K/zinc oxide arrester is composed of Composed of three sections, the 750KV zinc oxide arrester consists of four sections. The zinc oxide arrester is mainly composed of lightning protection components and an insulating base. A voltage equalizing ring is installed on the top of the 220K/zinc oxide arrester to improve voltage distribution.
The internal structure of the zinc oxide arrester is composed of zinc oxide varistor, insulating bracket, sealing gasket, pressure relief device, etc. Zinc oxide varistor is a multi-component polycrystalline ceramic semiconductor with holes inside. Zinc oxide varistor is mainly made of zinc oxide, with a small amount of metal additives added. They are fully mixed, granulated and formed, and then roasted at high temperature. If you use a microscope to observe the resistor sheet, it is composed of zinc oxide grains, spinel grains, grain boundaries and pores. The zinc oxide grains have a resistivity of 0.01-0.1 and a size of 10-30. The solid solution is micro-ribbed. C0, HX and other elements, spinel grains are composite zinc oxide composed of zinc oxide and antimony oxide. In addition, they also contain impurities such as C0, MN, M, CR, etc. The particle size is about a few microns, and the grain boundary is composed of a variety of additives. It is a rich area where additives are afraid. It can be seen that the zinc oxide grains with a grain size of 10 are surrounded by an oxide film with a thickness of about 0.1 formed by the additives. The pores are distributed in the zinc oxide grains and the grain boundary layer. Zinc oxide arrester resistors are usually fixed with nylon or polyester glass fiber rods with high mechanical strength and low moisture absorption capacity as supporting materials.
The external insulating cylinder is isolated from the porcelain sleeve. In order to improve the electric field distribution, a capacitor is connected in parallel with the zinc oxide arrester at 500K/ and above to increase the total current of the zinc oxide arrester resistor to achieve better voltage equalization effect.
Zinc oxide arrester jacket structure
Porcelain jacketed zinc oxide arrester
Porcelain jacketed zinc oxide arresters are currently less commonly used. There is a gap between the jacket and the valve core of the porcelain jacketed zinc oxide arrester. The gap is generally filled with sulfur hexafluoride under a certain pressure. Composite jacketed zinc oxide arresters are also called silicone rubber zinc oxide arresters)
10KV zinc oxide arresters are the most commonly used form at present. Compared with porcelain-coated zinc oxide arresters, composite jacketed zinc oxide arresters have a series of advantages such as small size, light weight, good explosion-proof and sealing properties, large creepage distance, pollution resistance, simple manufacturing process, and compact structure, so they are very popular among users.
