Research On High-Altitude Electromagnetic Pulses Response Characteristics Of Series-Wound Surge Protector Device

High-altitude Electromagnetic Pulses(HEMP)are very destructive for electronic and electric power equipment.HEMP can cause electromagnetic interference and structural damage to the antenna system through the front door coupling.It is one of the main technological means of HEMP protection through Surge Protector Device(SPD)discharge voltage.However,the protective parameters of SPD are mainly aimed at the Lightning Electromagnetic Pulse(LEMP)and Electrostatic Discharge Electromagnetic Pulse(ESD EMP).And under the action of HEMP,there may be a great difference and the corresponding selection may no longer be applicable.Even worse,protected lines or equipment may be destroyed due to self-failure or failure to activate protection because the HEMP has faster leading edge and higher amplitude.In order to improve the survivability of the information transmission system under the HEMP attack and ensure the normal operation of the antenna port,this article explains the feasibility of serial SPD for antenna protection from a theoretical perspective,and establishes a direct injection system for HEMP.The response characteristics of the Gas Discharge Tube(GDT),the Metal Oxide Varistors(MOV)and the series SPD were studied respectively.This article also compares the response characteristics under fast and slow pulses,and summarizes the selection basis of serial SPD used for antenna port protection.The specific research contents are as follows:(1)By analyzing the operating principle and protection parameters of GDT,MOV and combined SPD,the difference of response parameters under fast and slow pulses,and the influence of these differences on the response characteristics of protection devices are compared.For example,the GDT response time can be increased from the ?s level under LEMP injection to the ns level under HEMP injection.From a theoretical point of view,through the SPD analysis of the series,it is believed that the voltage limit of the MOV can be used to cut off the freewheeling problem of the GDT.The series connection of the two solves the problem that the MOV is not commonly used in high-frequency signal protection lines due to the large junction capacitance.Therefore,the problem of whether the serial SPD meets the antenna protection requirements is explained.(2)According to the test requirements,the pulse injection system,the current test system and the transmission line system are established,and the appropriate test equipment is selected through the analysis of the measurement principle.According to IEC 61000-4-24,MIL-STD-188-125-2 and GJB 8848-2016,respectively design square wave pulse injection experiment plan and HEMP injection experiment plan,carry out GDT and MOV and series SPD injection experiment.(3)The change of the response time of GDT under the injection of square wave pulse is analyzed,it is found that the response time of GDT decreases with the increase of the amplitude of the injected voltage and the difference is decreasing.And the effects of various protection parameters of GDT,MOV and series SPD pulse breakdown voltage,overcharge peak voltage,response time,clamping voltage and voltage change rate are analyzed.Finally,the protection parameters of series SPD and GDT and MOV are compared,the improvement of a single device is analyzed,and the selection basis of the choice of surge protector at the front end of the antenna is given.