Research On Insulation State Assessment Method Of Solid Insulation Switchgear

Compared with the traditional switchgear,the solid insulated switchgear with epoxy resin as the main insulation and supporting structure has the characteristics of small area,environmental protection and maintenance-free.It has a good market application prospect and is expected to replace the gas insulated products.However,solid insulated switchgear lacks long-term safe operation experience,and its long-term operation reliability test method is not perfect,so it is necessary to study its insulation failure and aging process under long-term operation conditions.In this paper,based on the operating conditions,the three-dimensional model of the core part of solid insulated switchgear,the embedded pole,is established,and the main distribution area of the insulation stress of epoxy resin material is obtained.Accelerated electrical aging test was carried out on the qualified specimens verified by equivalence from electrode samples with different structures based on the structural characteristics of the above parts,from which the electrical aging life of specimens is obtained and the insulation parameters at different aging stages are measured,and the corresponding relationship between the insulation parameters and the aging life of the specimens is mainly studied.The test results show that the main insulation stress area of switchgear under normal working conditions is located in the inlet and outlet bushing,and the insulation performance of this part is the key to affect the normal operation of the solid insulated switchgear;In the process of electrical aging,the development of partial discharge shows a trend of segmentation,and the dielectric loss angle changes linearly with aging time;It can be used as a reference for evaluating the insulation state of solid insulated switchgear that grey target theory algorithms and classification standard of electrical equipment insulation state are improved.