Electric tree test device of silicone rubber material for cable accessory and sample manufacturing method

Abstract

The invention discloses an electric tree test device for a silicone rubber material for cable accessories and a sample manufacturing method. The method includes the steps of adding semi-conductive silicone rubber into xylene, then spraying and curing the surface of a silicone rubber insulation sample, then cutting the silicone rubber insulation sample into a high-voltage electrode with a triangular longitudinal section end part, then adhering the high-voltage electrode to the surface of the silicone rubber insulation sample, and carrying out high-temperature vulcanization to obtain a piezoelectric electrode silicone rubber sample; putting the piezoelectric electrode silicon rubber sample wafer into a mold, injecting glue, and carrying out high-temperature vulcanization to obtain a sample;and cutting at a position 2 mm away from the tip of the high-voltage electrode, and adhering a ground electrode with a flat plate structure to the section. The tip of the high-voltage electrode does not have air gaps and cracks under large mechanical deformation by adopting the test sample provided by the invention. Moreover, an electrical tree in an actual cable accessory is generally developed from semiconduction to insulation, and the semiconductive material as a high-voltage electrode is more similar to the actual working condition of the cable accessory.

Description

technical field [0001] The invention relates to an electric tree branch test device and a sample preparation method of silicone rubber materials used for cable accessories, and belongs to the technical field of research on the electric tree branch resistance performance of insulating materials. Background technique [0002] As the production technology of high-voltage power cables and accessories in my country becomes more and more mature, high-voltage cables gradually replace overhead lines as the main channel for power transmission in cities, and the consumption of cable accessories also increases. Cable accessories are the most vulnerable link in the power system. 70% of power system failures are caused by the failure of cable accessories. The mainstream view is that the electrical branches inside the accessories are the main reason for the failure of cable accessories. At present, the installation of cable accessories mostly adopts prefabricated structures. Silicone rubb...

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Problems solved by technology

Since the silicone rubber material is a superelastic material with low tear strength, the steel needle as a high-voltage electrode is prone to cracks and air gaps at the needle tip under the action of large mechanical deformation, and even tears the sample from the needle tip, which seriously affects the test. result

Individual researchers used steel needles to make silicone rubber samples with a needle-plate electrode structure, and studied the initiation and growth characteristics of silicone rubber electrical trees under compressive force and tensile deformation, but the maximum stretching ratio is 30%. Far lower than the expansion rate of about 45% of common high-voltage cable accessories, it cannot reflect the characteristics of electrical branches under the actual deformation size of cable accessories, and it is difficult to realize the test of large mechanical deformation

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