Simulation Study Of Electromagnetic Wave Propagation Characteristics In GIS Based On COMSOL

GIS(Gas Insulation Switchgear,GIS)will inevitably produce insulation defects in production,transportation and operation.The insulation defect of GIS is mainly manifested by PD(Partial Discharge,PD).Long-term PD will cause damage to the insulation material in GIS and lead to the decline of insulation performance.Serious PD will also cause a large range of power failure,resulting in a large number of economic losses.As the partial discharge signal contains a large amount of insulation state information,it can also reflect the real situation of the high-voltage electrical insulation equipment.Therefore,partial discharge detection can provide with hazard latent insulation flaws early instructions,its testing can not only detect the GIS introduced during the process of manufacture and installation of insulation defects,and can effectively evaluate the insulation defect type and severity,in order to take timely measures,to avoid further deterioration of the insulation defects.GIS equipment lead to the internal structure of special internal partial discharge frequency components is relatively complex,through field test research data obtained by the strong electromagnetic interference,so through the establishment of GIS simulation model,the electromagnetic wave propagation regularity of its internal partial discharge excitation,can effectively improve the efficiency of study,reduce research costs.However,in recent years,in the simulation analysis of partial discharge in GIS,the excitation source is mostly replaced by triangle wave or gaussian function,which makes it difficult to obtain the real partial discharge electromagnetic wave.Based on this,this paper uses COMSOL software to complete the establishment of GIS partial discharge simulation model,and uses four typical mathematical models of partial discharge signals as the excitation source.The main work of this paper is as follows:(1)In the framework of finite element theory,COMSOL was used to build the linear GIS simulation model.On this basis,the influence of pulse width and amplitude of excitation source on electromagnetic wave propagation of GIS was studied.And the time delay and attenuation characteristics of electromagnetic wave propagation in GIS.Then,by establishing the T-type GIS model and L-type GIS model,the influence of GIS structure on electromagnetic wave propagation characteristics was studied,and the general law of electromagnetic wave propagation of partial discharge in GIS was obtained.(2)Then,by establishing the T-type GIS model and L-type GIS model,the influence of GIS structure on electromagnetic wave propagation characteristics was studied,and the general law of electromagnetic wave propagation of partial discharge in GIS was obtained.(3)Using four typical mathematical models of partial discharge of insulation defects as the excitation source,research the discharge characteristics of four different types of discharges in GIS.and the propagation process of four typical insulation defects partial discharge electromagnetic waves in the coaxial cavity of GIS was studied.