Study On Discharge Characteristics Of Epoxy Resin Insulating Surface In Condensation State

With the development of The Times,in recent years,new environmental protection solid insulation switchgear has been widely concerned,and epoxy resin as the main insulation material of solid insulation switchgear in the operation of equipment insulation deterioration problem has gradually been paid attention to.Due to the special climate environment in southwest China,solid insulated switchgear works in the environment of high temperature and high humidity,low temperature and high humidity for a long time,its surface is easy to condense water droplets and induce partial discharge,which leads to the insulation deterioration of materials,and eventually leads to the occurrence of insulation surface flashover and other accidents,posing a threat to the entire power network.In view of the solid insulation switchgear condensation phenomenon at present,and put forward the physical dehumidification,structural optimization,such as condensation prevention strategies,but of the epoxy resin insulating surface in different environments lon discharge characteristic research is relatively small,and the lack of temperature,humidity,filthy,and the degree of aging lon discharge characteristics and the influence factors,such as quantitative analysis.Therefore,it is necessary to study the condensation phenomenon and discharge characteristics under different environmental factors to provide a new idea for a more efficient anti-condensation strategy of solid insulated switchgear.(1)This article first made to dimethylamino methyl phenol(DMP-30)as the promoter,bisphenol A epoxy resin(E-51)/methyl 4 hydrogen phthalic anhydride(MTHPA)samples of epoxy resin curing system,and USES the environment box,air compressor,such as ultrasonic hair sprayer device for simulating condensation environment,and then set up experimental platform for experimental steps,Condensation discharge experiments were carried out according to different environmental factors and aging degree.After that,the condensation state,condensation quality,flashover voltage,leakage current and other characteristics of the experimental samples were analyzed,and the law of different environmental factors and condensation discharge characteristics of epoxy resin surface was obtained.(2)In this paper,the condensation discharge characteristics of epoxy resin under different environmental factors were studied.The results show that the increase of temperature difference and relative humidity will lead to the increase of condensation quality.In high humidity environment,the increase rate of condensation quality is accelerated.Under the condition of pollution,hydrophilic electrolyte and strong absorbent insoluble matter have influence on the quality of condensate.The change of temperature and humidity can not directly affect the condensation flashover voltage and leakage current on the surface of epoxy resin,but mainly depends on the quality of the condensation.The larger the mass of the condensation,the lower the condensation flashover voltage,the larger the leakage current amplitude,and the stronger the waveform periodicity.And filth can directly affect the surface condensation flashover voltage and leakage current,the rise of salt density makes the Na Cl more soluble in water to produce conductive ions,the ash of rise can cause surface moist with uncleanness,and changed the dew distribution form,increase the quality of gel and both are able to make any condensation flashover voltage fell sharply,leakage current amplitude increase.In addition,Na Cl dissolved in water makes the surface of epoxy resin prone to partial discharge phenomenon under strong electric field,resulting in distortion of leakage current waveform.(3)According to different hot and humid when corona aging long samples to analyze the surface characteristics of epoxy resin and gel discharge experiment results show that the epoxy resin hydrophobic loss serious after aging,make network structure decomposition,the aging time of 48 h,96 h of the sample surface holes,cracks,volume and surface resistivity are because of the destruction of the structure decreased;As the aging degree increases,the quality of condensation on the surface of epoxy resin increases,the particle size of dew drops increases,and the area of water film expands,leading to the increase of conductive channels.As a result,the condensation flashover voltage drops sharply compared with that of unaged samples,and the leakage current amplitude increases significantly and periodically strengthens.Both environmental factors and damp-thermal corona aging can affect the condensation state and discharge characteristics of epoxy resin surface,but the influence ways are different.The former mainly changes the surface medium,while the latter changes the structure of the material itself.