Analysis of Insulation Structure Design for High Altitude UHV Reactor Bushing

Abstract

The ultra high voltage reactor bushing is the important equipment to realize the electrical connection between the reactor and the valve tower. The high altitude application environment puts forward higher requirement for electrical structure design of reactor bushing. The paper mainly discusses the design of the internal and external insulation structure. The design and analysis of the tail of the bushing, the corona ring and the inner insulation of bushing have been done. The three dimensional electric field simulation model has been set up to calculate and analyze the insulation performance of the bushing. The results show that the elevation correction of the external ring and the flash-over voltage of the porcelain under high altitude should be done, and the calculation shows that the correction coefficient are 2.07 and 1.36 respectively, and the end of bushing should install with double type ring. The insulation distance of the hollow composite insulator is designed as 8500mm. The insulation distance of the bushing tail is designed as 1955mm. The maximum field strength of the corona ring is 1.251kV⋅mm−1, and maximum field strength on the surface of tail corona ring is 16.96kV⋅mm−1. The axial field strength of the bushing core near center conductor is higher than the flange side, and the maximum field strength is 0.55kV⋅mm−1. The results of the paper can provide the theoretical basis for the design of the insulation of the reactor transformer bushing used in the UHV transmission project.