Research On Optimization Of Electromagnetic Shielding Methods For Secondary Equipment In Substations And Converter Stations

With the development of UHV transmission and the increase in voltage levels.the electromagnetic radiation nuisance generated by substations and converter stations is becoming more and more intense.On the one hand,as power secondary systems in substations and converter stations become more closely integrated with power primary systems,the on-site secondary equipment is exposed to a harsher electromagnetic environment.On the other hand,with the development of wireless communication technology,new wireless communication equipment is widely used in the secondary system of substations and converter stations,but the electromagnetic shielding problem of such equipment has yet to be solved.Therefore,in order to improve the anti-interference capability of power secondary equipment,it is necessary to study the electromagnetic shielding of power secondary equipment in substations and converter stations and propose corresponding optimisation.In this paper,the electromagnetic shielding characteristics of traditional power secondary equipment,new power secondary equipment and on-site cabinets are researched,and the impact of multiple factors on shielding effectiveness,such as electromagnetic wave incidence direction,polarization direction,nature of disturbance sources,gap size,ventilation holes,shield thickness,lap.and paint application is simulated and analyzed,and the electromagnetic shielding law of secondary equipment under far and near fields is revealed.Finally,the optimization of the parameters of electromagnetic shielding of secondary equipment and the corresponding conclusions are proposed.For on-situ cabinets,a double shielding door with flexible reed is proposed as an improvement measure,which can improve the shielding effectiveness of in-situ cabinets by 20dB.In this paper,the electromagnetic shielding of valve halls is investigated in relation to the low shielding effectiveness of valve halls in flexitransfer stations with inlet and outlet lines.The effect of the inlet and outlet lines on the shielding effectiveness of the valve hall is investigated.Finally,two improvements were proposed,the addition of a magnetic ring or bypass capacitor at the valve hall lead-in,both of which would enable the shielding effectiveness of valve hall to up to 40dB.