465 / 2017-05-07 01:30:20

Dielectric Characteristics of Composite Insulationin Nitrogen Insulated Ring Main Unit

13400,13875,13876,13487,13877

Nitrogen Insulated Ring Main Unit is a key component in power switchgear, to which the N2 is introduced in order to substitute the SF6 gas in distribution system.However, the breakdown criteria for the composite insulation in N2 gas still remains unclear for the development of the switchgear. The objective of this paper is to determine the dielectric characteristics of the composite Insulation in N2 insulated ring main unit.The material of the insulator is enclosed stainless steel. The diameter of the insulator is 20 mm. The height of the insulator is 50 mm. Three kinds of impact factors are taken into consideration in order to investigate the dielectric characteristics of the compound insulation. These factors include the inhomogeneity r/d of the electric field, the gauge pressure p of the N2, the electrodes gaps l. Result shows that the inhomogeneity r/d is the prominent impact factor for dielectric strength of the compound insulation. The dependence of the breakdown voltage U on the above three impact factors are achieved by performing the simulation of electric field and typical voltage withstand test.