Internal Arcing Simulation And Cabinet Strength Calibration Of 12kV Switchgear

Nowadays,12 kV switchgear are widely used in urban power supply and distribution system.But due to the different of design level,manufacture process,installation methods and various the quality of the product,there are a lot of problems in the operation.The internal arcing fault is an inevitable and destructive fault,but once it happened,it will brought harms to personal safety and electrical equipment.Using simulation and experiment to study the process of internal acting fault can effectively reduce the probability of the internal arcing faults.In this research,the basic concepts of the internal arcing in switchgear is briefly introduced,such as arc fault characteristic,mechanism and other theories,which determine the value of the internal arcing simulation calculation in the switchgear.According to the structural characteristics of the different switchgear,the SGC1-12(Z)switchgear of XJ Group is selected as calculated cabinet type in this research.The internal arcing experiment in switchgear is carried out at the test station,and it passed.Secondly,the coupling models are established by COMOSL Mutiphysics software through the finite element simulation analysis,which combined with heat transfer theory and hydrodynamics theory.In the simulation process,according to change the length and depth of the pressure relief plate to analyze the different circumstances of the internal combustion process changes.Finally,the cabinet strength of the switchgear is calculated to provide the basic theory for the design.Cabinet strength of the switchgear was checked by using the maximum tensile stress theory(first strength theory),which based on the simulation results.The final result shows that the switchgear cabinet can withstand the tremendous impact of the internal arcing,and meet the requirements of the cabinet strength.On this basis,the shape of the switchgear's cabinet door is changed,in the arc process the doors with different shapes that suffer the impact by internal arcing areanalyzed respectively,and make the impact force to the cabinet is smallest.The results before and after the optimization arc comparative analyzed,the optimal conclusion.The research provides a theoretical basis for the switchgear design.