Application condition of 40.5kV air insulated metal enclosed switchgear with VCB in China

In the advantage of high reliability, environment friendly and maintenance-free, VCB has possessed the large-scale market capacity in China and other countries in worldwide. At the same time, compact 40.5kV air insulated switchgear with VCB is mostly used in power substation of 220kV and industry consumer with heavy loads. Practical operation of many years has proved that many faults will occur in 40.5kV air insulated metal enclosed switchgear. Statistic date shows the most fault and failure is resulted due to the poor insulation performance. Based on the different appearance of fault and failure occurred in the operation field of switchgear, the root cause which results in insulation fault and failure were investigated in this paper, through simulation and electrical test. Detail analysis on fault and failure show that there are a lot of factors which can lead to the different faults and failure mode. Some key cause can be deduced as following: selection of insulation part and material, design of insulation parts, manufacture processing of insulation parts, assembly processing of components used in air insulated switchgear, filed environment and switchgear maintenance. For improve the insulation performance of air insulated metal enclosed switchgear, some FEA simulation and electrical tests were implemented in this paper, test results prove that simulation is a useful tool to optimize the quality of insulation parts.