Electric Field Simulation And Optimized Design Of Contact Network Insulators In Saline-alkali Zone

Railway is the artery of national economy and an important infrastructure,meanwhile,it is a necessary condition that railway is on a normal running depending on safe and reliable power supply.Catenary insulator acts as a supporter and electrical insulation to the line of contact.Different installation methods make the insulator polluted in different spots,which resulting in the occurrence of pollution flashover accidents.The composite insulator is light in weight,strong in strength and has better anti-pollution flashover performance,which flashover characteristics is connected with the shed.The electric field distortion on the surface of insulator will lead to the occurrence of electric arc,and the further development of electric arc will cause flashover accident.Therefore,the study of electric field intensity and potential distribution on insulator surface can effectively prevent flashover accidents.There are two main methods for electric field and potential distribution of insulators: experimental method and numerical simulation.The test required much time and effort and test equipment would have a certain impact on the results with a certain degree of dispersion.Numerical simulation can effectively avoid interference and the results are highly analyzable,which has become a mainstream method in academic research.For now,it is rare that numerical simulation methods can be used for multi-physical field coupling of insulators.Therefore,it is necessary to apply numerically calculation on the electric field intensity and potential distribution of catenary insulators in multi-physical fields,and to design insulators with better structure.This research took the wrist arm FQBG-25/12 bar insulator,as object,which is used in catenary.An equal-proportion insulator model was established in COMSOL Multiphysics,the coupled finite element software for multiple physical fields.And the pre-processing settings of the model were completed,which including material property parameters,definition of physics,finite element meshing and calculation.The electric field is calculated to obtain the surface field strength and potential distribution of the insulator under clean condition.To set up two bracket insulator installation: horizontal and inclined types,and wind tunnel model,a numerical simulation of dirt depositioin was ongoing in the two types of installation and the surface electric field of insulator and potential distribution value were calculated in the condition of electric pollution state for analysing fouling laws and the distribution of potential and the electric field in two different corrupt installation.Based on the electric field distribution on the insulator surface,the optimized shed-model would be set up to carry out wind tunnel simulation,and the pollution,potential and electric field distribution of the optimized insulator were compared with that of the model insulator,which would provide theoretical support for the selection and experimental research of insulators in saline and alkaline areas.