Research On Transient Response Characteristics Of Conductive Protection Device Under Strong Electromagnetic Pulse

Strong electromagnetic pulse is a transient pulse environment with very strong destructive power.It can be coupled to the electronic device via the front door or the back door,which may interfere with the normal operation of the electronic device and even damage the device.Conduction protection devices are an effective protective measure against electromagnetic pulses.However,the current research on the response characteristics of conduction protection devices is mainly about lightning and static electricity.Due to the nonlinearity of the device itself,its response characteristics under the action of ns-level strong electromagnetic pulse of HEMP are not yet clear,and the protection performance parameters are also unknown.The method is not known,and there is also a lack of protective device Pspice model for strong electromagnetic pulse.Therefore,this dissertation builds a direct injection test system based on double exponential pulses,and clarifies the protection parameters and extraction methods of protective devices with strong electromagnetic pulse.Based on the test system constructed,the nonlinear transient response of the device under HEMP was studied.A Pspice model of the device under strong magnetic pulse was established.1)The characteristics of electrostatic(ESD),lightning(LEMP),and high altitude nuclear electromagnetic pulse(HEMP)waveforms are compared and analyzed.The HEMP double exponential pulse has the characteristics of fast rising edge,large energy,and wide spectrum.The test methods for conducting protection devices specified in the relevant standards are comparatively analyzed.According to the US military standard MIL-STD-188-125,the test scheme and configuration for the transient response characteristics of the conduction protection devices based on double exponential pulse direct injection have been established.Finally,the effects of charging time and external tuning inductance on the parameters of the double exponential pulse waveform were analyzed.Thus,the parameters of the double exponential pulse can be changed to study the effect on the transient response characteristics of the protection device.2)Through the analysis of the protective mechanism of the protective device,the pulsed peak voltage,clamp voltage,pulse peak time and clamping time and high-frequency inter-electrode capacitance and other protective performance parameters affecting the HEMP pulse are determined,and the pulse at the ns level is given.Under the definition of the device parameters,the transient response waveforms of the slave devices under the HEMP are processed by the peak filter,median filter and moving average filter due to many reasons such as oscillation of the test waveform,and the protective performance parameters are extracted by interpolation.3)Using the double exponential pulse direct injection test system constructed in this paper,the transient response of gas discharge tubes,varistors and transient suppression diodes under different current peaks or different current change rates in the injected double exponential pulses was measured.Based on the sample statistics and comparative analysis of test data,the least squares approximation analysis is used to obtain the pulse peak voltage,overshoot,clamp voltage,trigger time,clamp of typical transient suppression devices at different current peak and rising edge current rates.Time and other protective performance parameters change deduction rule.The similarities and differences of the protective performance parameters in different models of the same device were studied.The short-circuit failure of TVS under HEMP is analyzed.Provides magnitude and regular support for the design of protective circuits.4)According to the rising edge,the FWHM,the current peak value and the peak time of the double exponential pulse waveform,the characteristic parameters of the double exponential function are extracted.Based on this,the Pspice model of the double exponential pulse source is established and analyzed according to the previous transient response characteristics.The parameters of the protection performance parameters and the segmented analysis of the dynamic volt-ampere characteristics of the protection device under the HEMP are fitted to the curve data,and equivalent devices such as diodes,tertiary tubes,and voltage control sources are used to replace the equivalent devices of non-linear devices,and a suitable nanosecond level is established.An impulse-responsive macro-model of the behavior of the Pspice nonlinear circuit of a gas discharge tube and a varistor.Combined with the pulse source circuit model built in front,the Pspice model was verified.