A gas discharge tube HEMP response pspice circuit model and simulation method thereof

Abstract

The present application relates to a kind of gas discharge tube HEMP response PSpice circuit model and its simulation method;Solve the problem that cannot realize the simulation of the response of gas discharge tube under the action of HEMP;Circuit model includes first subcircuit, second subcircuit and main circuit;First subcircuit includes negative ground, positive and load circuit Rc connected excitation source Vc, load circuit Rc ground;Second subcircuit includes negative ground, end and sub load circuit connected sub pulse source circuit, sub load circuit ground, sub gas discharge tube circuit one end and sub load circuit connection, sub gas discharge tube circuit the other end ground, main circuit includes negative ground, positive and main load circuit connected main pulse source circuit, main load circuit ground, gas discharge tube circuit one end and main load circuit connection, the other end ground;Gas discharge tube inductance Lg one end and gas discharge tube action simulation circuit connection, the other end ground;The present application also proposes the simulation method based on above-mentioned model.

Description

Technical Field

[0001] This invention relates to the field of high-attitude electromagnetic pulse (HEMP) protection technology, specifically to a PSpice circuit model and simulation method for the HEMP response of a gas discharge tube. Background Technology

[0002] High-altitude electromagnetic pulses (HEMPs) are characterized by high field strength, wide spectrum, and broad range of action. They can create strong electromagnetic interference at the ports of power electronic equipment through coupling paths such as antennas and cables, affecting the normal operation of the equipment and even causing damage. Installing a gas discharge tube (GDT) between the equipment input and ground creates a short-circuit path from the input to ground during a HEMP impact, discharging the pulse interference current and protecting the equipment from damage. Due to its high current-carrying capacity and low parasitic capacitance, the GDT is the most commonly used protective device in HEMP protection.

[0003] To simulate the circuit response of gas discharge tubes, as early as the 1990s, international scholars established SPICE (Simulation program with integrated circuit emphasis) circuit models for GDTs. Anders Larsson summarized several typical cases in his paper "Numerical simulation of gas discharge protectors - a review". These models start from the physical process and use multiple parameters to simulate the operating characteristics of gas discharge tubes. They are relatively complex in terms of model usage and have poor simulation convergence. In 2008, Julio Zola proposed a simplified PSpice model of gas discharge tubes based on thyristors and Zener diodes (see "Gas Discharge Tube Modeling With Pspice"), which reduced the modeling difficulty to a certain extent and improved the simulation convergence. Domestically, Xiao Zanliang et al. designed a PSpice circuit model for gas discharge tubes based on voltage-controlled switches ("Establishment of a PSpice-based simulation model for gas discharge tubes"); Ma Langkai proposed a PSpice circuit model for gas discharge tubes combining transistors and diodes ("Research on transient response characteristics of conductive protection devices under strong electromagnetic pulses"); Ma Haijie et al. provided a PSpice circuit model to improve the simulation response speed of gas discharge tubes ("PSpice modeling, simulation and experimental testing of GDT").

[0004] The PSpice models described above have largely solved the problem of simulating the circuit response of gas discharge tubes under lightning electromagnetic pulse (LEMP) action. However, these models are no longer applicable to the simulation of the response of gas discharge tubes under HEMP action. The main reason is that LEMP waveforms are on the order of microseconds, while HEMP waveforms are on the order of nanoseconds. Under these two different time scales, the operating mechanism and characteristics of gas discharge tubes are significantly different. Summary of the Invention

[0005] To address the technical problem that existing models cannot simulate the response of a gas discharge tube under HEMP, this invention proposes a PSpice circuit model and simulation method for the HEMP response of a gas discharge tube.

[0006] The technical solution of the present invention is as follows:

[0007] A PSpice circuit model for the HEMP response of a gas discharge tube, characterized by the following features:

[0008] It includes the first sub-circuit, the second sub-circuit, and the main circuit;

[0009] The first sub-circuit is used to generate the action time-amplitude characteristic curve of the gas discharge tube, including an excitation source Vc and a load circuit Rc. The negative terminal of the excitation source Vc is grounded, the positive terminal of the excitation source Vc is connected to one end of the load circuit Rc, and the other end of the load circuit Rc is grounded. The excitation source Vc is used to output the action voltage V_curve of the characteristic curve.

[0010] The second sub-circuit is used to generate HEMP conducted environment excitation waveform, including a sub-pulse source circuit, a sub-load circuit, and a sub-gas discharge tube circuit. The negative terminal of the sub-pulse source is grounded, and the positive terminal is connected to one end of the sub-load circuit. The other end of the sub-load circuit is grounded. One end of the sub-gas discharge tube circuit is connected to one end of the sub-load circuit, and the other end of the sub-gas discharge tube circuit is grounded. The sub-pulse source circuit is used to output the excitation signal voltage V_in.

[0011] The main circuit is used to simulate the circuit response after the HEMP conducted environmental excitation waveform is applied to the gas discharge tube. It includes a gas discharge tube action simulation circuit, a gas discharge tube inductor Lg, a main gas discharge tube circuit with the same structure as the sub-gas discharge tube circuit, a main pulse source circuit with the same structure as the sub-pulse source circuit, and a main load circuit with the same structure as the sub-load circuit. The negative terminal of the main pulse source circuit is grounded, and the positive terminal is connected to one end of the main load circuit, while the other end of the main load circuit is grounded. One end of the gas discharge tube circuit is connected to one end of the main load circuit, while the other end of the gas discharge tube circuit is grounded. One end of the gas discharge tube inductor Lg is connected to the gas discharge tube action simulation circuit, and the other end is grounded. The gas discharge tube action simulation circuit receives the action voltage V_curve of the characteristic curve output by the first sub-circuit and the excitation signal voltage V_in output by the second sub-circuit, and outputs the difference between the excitation signal voltage V_in and the action voltage V_curve of the characteristic curve, as well as simulating the action of the gas discharge tube to determine whether it provides protection for the main load circuit.

[0012] Furthermore, the gas discharge tube operation simulation circuit includes a voltage source V1, a voltage-controlled voltage source E1, a transistor Q1, a DC voltage source Vdc, a sampling resistor R1, a voltage-controlled switch S1, and a diode D1;

[0013] The negative terminal of voltage source V1 is grounded, and the positive terminal of voltage source V1 is connected to the positive input terminal of voltage-controlled voltage source E1. Both the negative input and negative output terminals of voltage-controlled voltage source E1 are grounded. The positive output terminal of voltage-controlled voltage source E1 is connected to the base of transistor Q1. Voltage-controlled voltage source E1 receives the operating voltage V_curve of the characteristic curve output by the first sub-circuit and the excitation signal voltage V_in output by the second sub-circuit, and outputs the difference between the excitation signal voltage V_in and the operating voltage V_curve of the characteristic curve. The emitter of transistor Q1 is connected to the sampling resistor R. One end of the circuit is connected to the ground, the other end of the sampling resistor R1 is grounded, the collector of transistor Q1 is connected to the positive terminal of DC voltage source Vdc, the negative terminal of DC voltage source Vdc is grounded, the emitter of transistor Q1 is connected to the positive input terminal of voltage-controlled switch S1, the negative input terminal of voltage-controlled switch S1 is grounded, the positive output terminal of voltage-controlled switch S1 is connected to one end of the main load circuit, the negative output terminal of voltage-controlled switch S1 is connected to one end of gas discharge tube inductor Lg, the other end of gas discharge tube inductor Lg is connected to the cathode of diode D1, and the anode of diode D1 is grounded.

[0014] Furthermore, the sub-pulse source circuit includes a charging capacitor C0, a switch U1, an inductor L0, and a resistor R0;

[0015] One end of the charging capacitor C0 is grounded, and the other end is connected to one end of the switch U1. The other end of the switch U1 is connected to one end of the inductor L0. The other end of the inductor L0 is connected to one end of the resistor R0. The other end of the resistor R0 is connected to one end of the sub-load circuit.

[0016] Furthermore, the sub-gas discharge tube circuit includes an inter-electrode capacitor Cg and an impedance Rg. One end of the inter-electrode capacitor Cg and one end of the impedance Rg are both connected to one end of the sub-load circuit, and the other ends of the inter-electrode capacitor Cg and the impedance Rg are both grounded.

[0017] Furthermore, the action time-amplitude characteristic curve of the gas discharge tube is generated through the following steps:

[0018] Step 1: Connect a load to the rear end of the gas discharge tube. Define the voltage across the load after the gas discharge tube has discharged as the residual voltage after the gas discharge tube has discharged.

[0019] Step 2: Output a pulse to the gas discharge tube with the output pulse voltage as the minimum operating voltage of the gas discharge tube. Measure the residual voltage corresponding to the end of multiple gas discharge tube discharges. Calculate and record the average value of the residual voltage amplitude and the average value of the half-width at half-maximum (WHM). Define the average value of the residual voltage amplitude as the operating voltage amplitude of the gas discharge tube under test, and the average value of the WHM as the operating time.

[0020] Step 3: Gradually increase the output pulse voltage until it reaches the maximum output voltage of the pulse source. At each voltage level, calculate and record the action voltage amplitude and action time in the same way as in Step 2. At least 10 different pulse voltage levels should be taken.

[0021] Step 4: Based on the action voltage amplitude and action time in Step 2 and Step 3, plot the "time-amplitude" curve of the gas discharge tube action with the action voltage amplitude as the vertical axis and the action time as the horizontal axis, and obtain the HEMP protection performance characterization of the gas discharge tube.

[0022] Furthermore, the voltage source V1 is set to 1V; the DC voltage source Vdc is set to 200V; the sampling resistor R1 is set to 1Ω; and the reverse breakdown voltage of the diode D1 is set to the arc voltage of the gas discharge tube.

[0023] Furthermore, the excitation source Vc is an editable excitation source Vc.

[0024] This invention also proposes a simulation method for the PSpice circuit model of the HEMP response of the above-mentioned gas discharge tube, which is characterized by including the following steps:

[0025] Step 1: Set the threshold for the difference between V_in and V_curve; start the first sub-circuit, the second sub-circuit, and the main circuit. The first sub-circuit and the second sub-circuit send the characteristic curve action voltage V_curve and the excitation signal voltage V_in to the gas discharge tube action simulation circuit, respectively.

[0026] Step 2: The HEMP conduction environmental excitation waveform is applied to the main gas discharge tube circuit. If the difference between V_in and V_curve is greater than or equal to the set threshold, the gas discharge tube action simulation circuit is turned on, indicating that the gas discharge tube is activated and the circuit model protects the main load circuit. Conversely, if the gas discharge tube action simulation circuit is not turned on, it indicates that the gas discharge tube is not activated and the circuit model does not protect the main load circuit.

[0027] Furthermore, in step 1, the threshold value of the difference between V_in and V_curve is set as the starting voltage of transistor Q1;

[0028] Step 2 is as follows:

[0029] The HEMP conducted environmental excitation waveform is applied to the main gas discharge tube circuit. As the amplitude of the excitation signal V_in increases, if the difference between V_in and V_curve is greater than or equal to the start-up voltage of transistor Q1, the collector-emitter junction of transistor Q1 is turned on, and the voltage-controlled switch S1 is turned on, indicating that the gas discharge tube has activated. The current generated by the main pulse source circuit is quickly discharged to the ground terminal through the gas discharge tube inductor Lg, which protects the main load circuit. The voltage across the main load is the residual voltage after the gas discharge tube has activated. Conversely, if the difference is less than or equal to the start-up voltage, the voltage-controlled switch S1 will not be turned on, indicating that the gas discharge tube has not activated, and the circuit model has not protected the main load.

[0030] The beneficial effects of this invention are:

[0031] This invention solves the problem that previous circuit models were not suitable for the HEMP field, and can more accurately simulate the circuit response of a gas discharge tube under HEMP conduction environment excitation, including waveform indicators such as residual voltage amplitude and half-width.

[0032] The circuit model proposed in this invention can be used to design HEMP protection circuits for electronic devices and to predict the protection effect of gas discharge tubes under HEMP. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the principle of the HEMP protection performance characterization system for gas discharge tubes with action time-amplitude curves.

[0034] Figure 2 The time-amplitude characteristic curve of the gas discharge tube under HEMP signal excitation;

[0035] Figure 3(a) is a comparison of residual voltage waveforms of different amplitudes with the "time-amplitude" curve;

[0036] Figure 3(b) is a comparison chart of the predicted protective performance of gas discharge tubes using the "time-amplitude" curve;

[0037] Figure 4(a) is a schematic diagram of the first sub-circuit embodiment of the present invention;

[0038] Figure 4(b) is a schematic diagram of the second sub-circuit embodiment of the present invention;

[0039] Figure 5 This is a typical double-exponential waveform in a HEMP conduction environment;

[0040] Figure 6 In the second sub-circuit, the voltage waveform across the sub-load is compared with the characteristic curve (C0 preset voltage 500V);

[0041] Figure 7 for Figure 6 In the simulation, the residual voltage waveform is shown (C0 preset voltage 500V).

[0042] Figure 8 In the second sub-circuit, the voltage waveform across the sub-load is compared with the characteristic curve (C0 preset voltage 1600V);

[0043] Figure 9 for Figure 8 In the simulation, the residual voltage waveform is shown (C0 preset voltage 1600V).

[0044] Figure 10 Comparison of simulated residual voltage waveform with experimental waveform (500V pulse source applied);

[0045] Figure 11 Comparison of simulated residual voltage waveform with experimental waveform (1600V pulse source applied);

[0046] Figure 12 The experimental results were compared with the simulated residual voltage waveforms of the two models (1600V pulse source applied).

[0047] Figure 13 The experimental results were compared with the simulated residual voltage waveforms of the two models (pulse source applied voltage 2500V).

[0048] Figure 14 This is a schematic diagram of the main circuit embodiment of the present invention;

[0049] In the diagram, 1 is a pulse generator; 2 is a current sensor; 3 is a gas discharge tube; 4 is an oscilloscope; and 5 is a load. Detailed Implementation

[0050] Based on the study of GDT's operational characteristics, a method for characterizing the HEMP protection performance of gas discharge tubes based on the action time-amplitude curve is proposed. The method for obtaining the action time-amplitude characteristic curve of the gas discharge tube is as follows:

[0051] Step 1: Establish a characterization system for the HEMP protection performance of gas discharge tubes based on action time-amplitude curves;

[0052] like Figure 1 As shown, the system includes a pulse generator 1, a current sensor 2, and an oscilloscope 4, with a load 5 installed inside the oscilloscope 4;

[0053] The output of pulse generator 1 is connected to the input of gas discharge tube 3 under test via a first cable. The output of gas discharge tube 3 under test is connected in series with load 5 in oscilloscope 4 via a second cable. One end of current sensor 2 is mounted on the first cable, and the other end is electrically connected to oscilloscope 4. The voltage value across load 5 in oscilloscope 4 is used as the residual voltage value of gas discharge tube 3. Gas discharge tube 3 is clamped and fixed by a test fixture. Pulse generator 1 is used to output a pulse source. In this embodiment, square wave pulse generator 1 is used, with a leading edge <1ns, pulse width >500ns, and maximum output voltage ≥4kV. Current sensor 2 is used to collect the current signal input to gas discharge tube 3 under test, and convert the collected current signal into an electrical signal that meets the requirements of oscilloscope 4 before sending it to oscilloscope 4. Oscilloscope 4 is used to measure the current signal of gas discharge tube 3 under test and the residual voltage value of gas discharge tube 3 after discharge.

[0054] Step 2: Experiment

[0055] 2.1: Set the initial voltage value A of the square wave pulse generator 1 to the minimum operating voltage of the gas discharge tube 3 under test;

[0056] 2.2: Turn on the square wave pulse generator 1 and adjust the output voltage of the square wave pulse generator 1 to the initial voltage A. The square wave pulse generator 1 outputs a square wave pulse source. When the square wave pulse source is at a high level, the gas discharge tube 3 works and discharges. When the square wave pulse source is at a low level, the gas discharge tube 3 does not work. After the gas discharge tube 3 finishes discharging, the oscilloscope 4 collects the waveform of the residual voltage of the gas discharge tube 3 after discharge across the load 5.

[0057] 2.3: Using the same output voltage value as in step 2.2, the residual voltage after the gas discharge tube 3 was measured 9 times to obtain the waveform of the residual voltage after the gas discharge tube 3 was discharged 10 times when the voltage value of the square wave pulse generator 1 was A.

[0058] 2.4: Adjust the output voltage of square wave pulse generator 1 to B, where B>A. Square wave pulse generator 1 outputs square wave pulse source. When the square wave pulse source is at a high level, gas discharge tube 3 works and discharges. When the square wave pulse source is at a low level, gas discharge tube 3 does not work. After the gas discharge tube 3 finishes discharging, oscilloscope 4 collects the waveform of the residual voltage of gas discharge tube 3 after discharge at both ends of load 5.

[0059] 2.5: Using the same output voltage value as in step 2.4, the residual voltage after the gas discharge tube 3 is measured repeatedly 9 times to obtain the waveform of the residual voltage after the gas discharge tube 3 is discharged 10 times when the voltage value of the square wave pulse generator 1 is B.

[0060] 2.6: Adjust the voltage of the square wave pulse generator 1 to C, where C>B. The square wave pulse generator 1 outputs a square wave pulse source. When the square wave pulse source is at a high level, the gas discharge tube 3 works and discharges. When the square wave pulse source is at a low level, the gas discharge tube 3 does not work. After the gas discharge tube 3 finishes discharging, the oscilloscope 4 collects the waveform of the residual voltage of the gas discharge tube 3 after discharge at both ends of the load 5.

[0061] 2.7: Using the same output voltage value as in step 2.6, the residual voltage after the gas discharge tube 3 is measured repeatedly 9 times to obtain the waveform of the residual voltage after the gas discharge tube 3 is discharged 10 times when the output voltage value of the square wave pulse generator 1 is C.

[0062] 2.8: Using the same method as steps 2.6-2.7, measure the residual voltage waveform of gas discharge tube 3 after discharge under different voltages until the voltage of square wave pulse generator 1 is equal to the maximum output voltage of square wave pulse generator 1, then proceed to step 2.9;

[0063] 2.9: Adjust the output voltage of square wave pulse generator 1 to N, where the value of N is equal to the maximum output voltage of square wave pulse generator 1. Square wave pulse generator 1 outputs square wave pulse source. When the square wave pulse source is at a high level, gas discharge tube 3 works and discharges. When the square wave pulse source is at a low level, gas discharge tube 3 does not work. After the gas discharge tube 3 finishes discharging, oscilloscope 4 collects the waveform of the residual voltage of gas discharge tube 3 after discharge across the load 5.

[0064] 2.10: Using the same voltage value as in step 2.9, the residual voltage after the gas discharge tube 3 is measured 9 times to obtain the waveform of the residual voltage after the gas discharge tube 3 is discharged 10 times when the voltage value of the square wave pulse generator 1 is N.

[0065] 2.11: For each voltage level, the average value of the residual voltage waveform after 10 experimental discharges of gas discharge tube 3 is taken as the operating voltage amplitude of gas discharge tube 3, and the average half-width of the residual voltage waveform after 10 experimental discharges of gas discharge tube 3 is the operating time.

[0066] 2.12: Plot the "time-amplitude" characteristic curve of the gas discharge tube with the action voltage amplitude as the vertical axis and the action time as the horizontal axis;

[0067] The above method is used to obtain the following: Figure 2 The action time-amplitude characteristic curves shown in Figure 3(a) represent the residual voltage and "time-amplitude" curves of the GDT under different amplitude square wave excitations. Figure 3(b) shows the GDT operating when a 1kV square wave excitation signal is applied across the GDT. When this signal intersects with the "time-amplitude" curve of the GDT, the GDT starts to operate, and the residual voltage drops to zero. The predicted waveform and the measured waveform have a high degree of consistency. In summary, the "time-amplitude" curve of the GDT can be used to predict and characterize the residual voltage waveform of the GDT (it can fully reflect the operating characteristics of the GDT under different HEMP conduction environment waveform impacts and predict the residual voltage waveform). However, this characteristic curve cannot be directly applied to the protection circuit design of gas discharge tubes, especially in combined protectors composed of gas discharge tubes and other protection devices (varistors, filters, etc.). Therefore, it is necessary to establish a PSpice circuit model for gas discharge tubes.

[0068] Based on the above-mentioned time-amplitude characteristic curve of the gas discharge tube, this invention proposes a PSpice circuit model for the HEMP response of a gas discharge tube, including a first sub-circuit, a second sub-circuit, and a main circuit.

[0069] The composition and connection method of each component are as follows:

[0070] As shown in Figure 4(a), the first sub-circuit includes an editable excitation source Vc and a load circuit Rc;

[0071] The negative terminal of the editable excitation source Vc is grounded, the positive terminal of the editable excitation source Vc is connected to one end of the load circuit Rc, and the other end of the load circuit Rc is grounded. The excitation source Vc is used to output the operating voltage V_curve of the characteristic curve. The data file of the editable excitation source Vc is the value of the "time-amplitude" characteristic curve of the gas discharge tube mentioned above. The load circuit Rc is an arbitrary value.

[0072] As shown in Figure 4(b), the second sub-circuit includes a sub-pulse source circuit, a sub-load circuit R_load, and a sub-gas discharge tube circuit;

[0073] The sub-pulse source circuit includes a charging capacitor C0, a switch U1, an inductor L0, and a resistor R0; the sub-gas discharge tube circuit includes an inter-electrode capacitor Cg and an impedance Rg. One end of the charging capacitor C0 is grounded, and the other end is connected to one end of the switch U1. The other end of the switch U1 is connected to one end of the inductor L0. The other end of the inductor L0 is connected to one end of the resistor R0. The other end of the resistor R0 is connected to one end of the sub-load circuit R_load. The sub-pulse source circuit is used to output the excitation signal voltage V_in. The other end of the sub-load circuit R_load is grounded. One end of both the inter-electrode capacitor Cg and the impedance Rg is connected to one end of the sub-load circuit R_load, and the other end of both the inter-electrode capacitor Cg and the impedance Rg is grounded. Here, the sub-load circuit R_load represents the port impedance of the protected device.

[0074] like Figure 14 As shown, the main circuit includes a main pulse source circuit, a main load circuit, a gas discharge tube inductor Lg, a main gas discharge tube circuit, and a gas discharge tube operation simulation circuit; the gas discharge tube inductor Lg is the equivalent inductance of the main gas discharge tube.

[0075] The main pulse source circuit and the sub-pulse source circuit have the same structure, including a charging capacitor C0, a switch U1, an inductor L0, and a resistor R0; the main gas discharge tube circuit and the sub-gas discharge tube circuit have the same structure, including an inter-electrode capacitor Cg and an impedance Rg; the main load circuit and the sub-load circuit are the same, and the main load circuit is R_load; the gas discharge tube operation simulation circuit includes a voltage source V1, a voltage-controlled voltage source E1, a transistor Q1, a DC voltage source Vdc, a sampling resistor R1, a voltage-controlled switch S1, and a diode D1;

[0076] One end of the charging capacitor C0 is grounded, and the other end is connected to one end of the switch U1. The other end of the switch U1 is connected to one end of the inductor L0. The other end of the inductor L0 is connected to one end of the resistor R0. The other end of the resistor R0 is connected to one end of the main load circuit R_load. The other end of the main load circuit R_load is grounded. One end of both the inter-electrode capacitor Cg and the impedance Rg is connected to one end of the main load circuit R_load, and the other ends of both are grounded. The negative terminal of the voltage source V1 is grounded, and the positive terminal of the voltage source V1 is connected to the positive input terminal of the voltage-controlled voltage source E1. The negative input and negative output terminals of the voltage-controlled voltage source E1 are grounded, and the positive output terminal of the voltage-controlled voltage source E1 is connected to the base of the transistor Q1. The voltage-controlled voltage source E1 receives the operating voltage V_curve of the characteristic curve output by the first sub-circuit and the excitation signal voltage V_in output by the second sub-circuit, and outputs the difference between the excitation signal voltage V_in and the operating voltage V_curve of the characteristic curve. The emitter of transistor Q1 is connected to one end of sampling resistor R1, and the other end of sampling resistor R1 is grounded. The collector of transistor Q1 is connected to the positive terminal of DC voltage source Vdc, and the negative terminal of DC voltage source Vdc is grounded. The emitter of transistor Q1 is connected to the positive input terminal of voltage-controlled switch S1, and the negative input terminal of voltage-controlled switch S1 is grounded. The positive output terminal of voltage-controlled switch S1 is connected to one end of the main load circuit R_load, and the negative output terminal of voltage-controlled switch S1 is connected to the inductor L of the gas discharge tube. One end of g is connected, and the other end of the gas discharge tube inductor Lg is connected to the cathode of diode D1. The anode of diode D1 is grounded. The voltage source V1 is set to 1V, the voltage-controlled voltage source E1 is set to (V(V_in)-V(V_curve)), the DC voltage source Vdc is set to 200V, the sampling resistor R1 is set to 1Ω, the gas discharge tube inductor Lg is determined according to the lead inductance of the gas discharge tube, and the reverse breakdown voltage of diode D1 is set to the arc voltage of the gas discharge tube.

[0077] The basic working process of the PSpice circuit model described above is as follows: The first sub-circuit characterizes the operating time of the gas discharge tube under different operating voltages, specifically the operating time-voltage characteristic curve of the gas discharge tube, and outputs the operating voltage V_curve of the characteristic curve; the pulse source circuit in the second sub-circuit generates a HEMP conduction environment excitation waveform with a specific leading edge and width (determined by the values ​​of charging capacitor C0, resistor R0, and inductor L0), and outputs the excitation signal voltage V_in; when this excitation signal acts on the gas discharge tube, the voltage-controlled voltage source E1 of the main circuit compares the excitation signal and the characteristic curve and outputs the difference between the excitation signal voltage V_in and the operating voltage V_curve of the characteristic curve. If, as the amplitude of the excitation signal increases, at a certain moment ( Let's call it T1. When the excitation signal amplitude is greater than the operating voltage amplitude of the characteristic curve, the output of the voltage-controlled voltage source E1 is greater than or equal to the start-up voltage of the transistor Q1. The collector-emitter junction of the transistor Q1 is turned on, and the DC voltage source Vdc generates a higher voltage at the sampling resistor R1, which in turn causes the voltage-controlled switch S1 to turn on. The current generated by the pulse source circuit is quickly discharged to the ground terminal through the gas discharge tube inductor Lg, which protects the main load circuit R_load. The voltage across the main load circuit R_load is the residual voltage after the gas discharge tube has acted. If, as the excitation signal amplitude increases, the output of the voltage-controlled voltage source E1 is less than the start-up voltage of the transistor Q1, then the voltage-controlled switch S1 will never turn on, indicating that the gas discharge tube has not acted and has not played its role in protecting the main load circuit R_load.

[0078] This invention also proposes a method for using the above-mentioned circuit model, including the following steps:

[0079] Step 1: Set the startup voltage of transistor Q1;

[0080] Start the first sub-circuit, the second sub-circuit, and the main circuit. The first sub-circuit and the second sub-circuit respectively send the characteristic curve action voltage V_curve and the excitation signal voltage V_in to the gas discharge tube action simulation circuit.

[0081] Step 2: The HEMP conduction environment excitation waveform is applied to the main gas discharge tube circuit. The voltage-controlled voltage source E1 receives the characteristic curve operating voltage V_curve and the excitation signal voltage V_in from the first and second sub-circuits and outputs the difference between the excitation signal voltage V_in and the characteristic curve operating voltage V_curve. If, as the amplitude of the excitation signal V_in increases, at time T1, the amplitude of the excitation signal V_in is greater than the amplitude of the characteristic curve operating voltage V_curve, the output of the voltage-controlled voltage source E1 is greater than or equal to the start-up voltage of transistor Q1, and the collector-emitter junction of transistor Q1 is turned on, and the DC current... The voltage source Vdc generates a high voltage at the sampling resistor R1, which in turn causes the voltage-controlled switch S1 to conduct, indicating that the gas discharge tube has activated. The current generated by the main pulse source circuit is quickly discharged to the ground terminal through the gas discharge tube inductor Lg, thus protecting the main load circuit. The voltage across the main load is the residual voltage after the gas discharge tube has activated. If, as the amplitude of the excitation signal V_in increases, the difference between the excitation signal voltage V_in and the activation voltage V_curve of the characteristic curve is always less than the start-up voltage of the transistor Q1, then the voltage-controlled switch S1 will never conduct, indicating that the gas discharge tube has not activated, and this circuit model has not protected the main load.

[0082] In this embodiment, the pulse source circuit of the second sub-circuit can generate a typical HEMP conducted environment double exponential waveform on the sub-load circuit R_load, such as... Figure 5 As shown. The waveform amplitude is determined by the preset voltage of the charging capacitor C0, and the waveform leading edge t... r ≈2.2L0 / (R0+R_load), waveform half-width t w ≈0.69(R0+R_load)×C0. In the first sub-circuit, import the time-amplitude characteristic curve data of a gas discharge tube, such as... Figure 2 As shown.

[0083] In this embodiment, the charging capacitor C0 = 4.5nF, the resistor R0 = 50Ω, the sub-load circuit R_load = the main load circuit R_load = 50Ω, the inductor L0 = 100nH, the inter-electrode capacitance of the gas discharge tube Cg = 1.2pF, the impedance (open circuit resistance) Rg = 0.5GΩ, and the inductance (lead inductance) of the gas discharge tube Lg = 60nH.

[0084] Scenario 1: Set the preset voltage of the charging capacitor C0 to 500V.

[0085] The simulation waveform of the voltage V_in across the sub-load circuit R_load of the second sub-circuit is as follows: Figure 6 As shown by the dashed line, its maximum amplitude is approximately 250V. Throughout the waveform's duration, the amplitude at each time point is lower than the characteristic curve V_curve. Figure 6(Solid line), at this time, the value of the voltage-controlled voltage source E1 in the main circuit (V(V_in)-V(V_curve))<0, the collector-emitter junction of transistor Q1 is not conducting, the voltage value of sampling resistor R1 is less than the operating voltage of voltage-controlled switch S1, voltage-controlled switch S1 is not closed, which is equivalent to the gas discharge tube not operating. The simulated voltage waveform across the main load circuit R_load of the main circuit is the simulated voltage waveform across the sub-load circuit R_load of the second sub-circuit, as shown in the figure. Figure 7 As shown ( Figure 6 (Expansion of the simulated waveform).

[0086] Scenario 2: Set the preset voltage of the charging capacitor C0 to 1600V.

[0087] The simulation waveform of the voltage across the sub-load circuit R_load of the second sub-circuit is as follows: Figure 8 As shown by the dashed line, its maximum amplitude is approximately 800V. At approximately 20ns, the voltage-controlled voltage source E1 in the main circuit (V(V_in)-V(V_curve)) > 0.7V, the collector-emitter junction of transistor Q1 is turned on, and the voltage value of the sampling resistor R1 is greater than the operating voltage of the voltage-controlled switch S1. Therefore, the voltage-controlled switch S1 closes, equivalent to the gas discharge tube activating. Most of the output current from the pulse source in the main circuit flows to the ground terminal through the inductor Lg of the gas discharge tube. The voltage across the main load circuit R_load rapidly decreases to the reverse breakdown voltage of diode D1 (characterizing the arc voltage of the gas discharge tube). The residual voltage waveform is as follows... Figure 9 As shown by the solid line.

[0088] Set the pulse source (preset voltage of charging capacitor C0) as described above, and conduct an excitation experiment on a certain gas discharge tube. When the pulse source is set to charge at 500V (case 1), the measured residual voltage waveform is as follows. Figure 10 As shown by the solid black line, the residual voltage waveform obtained from the simulation shows good agreement with the actual waveform. When the pulse source is charged at 1600V (case 2), the experimentally measured residual voltage waveform is as follows. Figure 11 The black solid line shows the residual voltage waveform obtained from the simulation ( Figure 11 Compared to the previous model, the two models show a better agreement. Therefore, the PSpice model proposed in this invention can better simulate the circuit response of a gas discharge tube under HEMP excitation.

[0089] To further illustrate the advantages of the model of this invention, the pulse source circuit settings remain unchanged, i.e., the excitation signal remains unchanged. Simulations are performed using the model proposed by Julio Zola. The simulation results are compared with the simulation results and experimental test results of the model of this invention as follows: Figure 12As shown in the comparison, the model of this invention is significantly superior to the Julio Zola model in terms of the accuracy of residual voltage waveform width simulation. With the preset voltage of charging capacitor C0 adjusted to 2.5kV, the simulation results of the two models are compared with the experimental results as follows. Figure 13 As shown, even with an increased excitation signal amplitude, the simulation results of the present invention still show good consistency with the experimental results. However, the Julio Zola model, except for the pulse width, also exhibits some deviations in amplitude simulation results compared to the experimental results. Other models mentioned earlier also suffer from similar issues because they are primarily designed for LEMP waveform excitation. The operating mechanism of the gas discharge tube under HEMP conduction environment excitation changes, rendering these models no longer applicable.

Claims

1. A PSpice circuit model for the HEMP response of a gas discharge tube, characterized in that: It includes the first sub-circuit, the second sub-circuit, and the main circuit; The first sub-circuit is used to generate the action time-amplitude characteristic curve of the gas discharge tube, including an excitation source Vc and a load circuit Rc. The negative terminal of the excitation source Vc is grounded, the positive terminal of the excitation source Vc is connected to one end of the load circuit Rc, and the other end of the load circuit Rc is grounded. The excitation source Vc is used to output the action voltage V_curve of the characteristic curve. The second sub-circuit is used to generate HEMP conducted environment excitation waveform, including a sub-pulse source circuit, a sub-load circuit, and a sub-gas discharge tube circuit. The negative terminal of the sub-pulse source is grounded, and the positive terminal is connected to one end of the sub-load circuit. The other end of the sub-load circuit is grounded. One end of the sub-gas discharge tube circuit is connected to one end of the sub-load circuit, and the other end of the sub-gas discharge tube circuit is grounded. The sub-pulse source circuit is used to output the excitation signal voltage V_in. The main circuit is used to simulate the circuit response after the HEMP conducted environmental excitation waveform is applied to the gas discharge tube. It includes a gas discharge tube action simulation circuit, a gas discharge tube inductor Lg, a main gas discharge tube circuit with the same structure as the sub-gas discharge tube circuit, a main pulse source circuit with the same structure as the sub-pulse source circuit, and a main load circuit with the same structure as the sub-load circuit. The negative terminal of the main pulse source circuit is grounded, and the positive terminal is connected to one end of the main load circuit, while the other end of the main load circuit is grounded. One end of the gas discharge tube circuit is connected to one end of the main load circuit, while the other end of the gas discharge tube circuit is grounded. One end of the gas discharge tube inductor Lg is connected to the gas discharge tube action simulation circuit, and the other end is grounded. The gas discharge tube action simulation circuit receives the action voltage V_curve of the characteristic curve output by the first sub-circuit and the excitation signal voltage V_in output by the second sub-circuit, and outputs the difference between the excitation signal voltage V_in and the action voltage V_curve of the characteristic curve, as well as simulating the action of the gas discharge tube to determine whether it provides protection for the main load circuit.

2. The PSpice circuit model for the HEMP response of a gas discharge tube according to claim 1, characterized in that: The gas discharge tube operation simulation circuit includes a voltage source V1, a voltage-controlled voltage source E1, a transistor Q1, a DC voltage source Vdc, a sampling resistor R1, a voltage-controlled switch S1, and a diode D1. The negative terminal of voltage source V1 is grounded, and the positive terminal of voltage source V1 is connected to the positive input terminal of voltage-controlled voltage source E1. Both the negative input and negative output terminals of voltage-controlled voltage source E1 are grounded. The positive output terminal of voltage-controlled voltage source E1 is connected to the base of transistor Q1. Voltage-controlled voltage source E1 receives the operating voltage V_curve of the characteristic curve output by the first sub-circuit and the excitation signal voltage V_in output by the second sub-circuit, and outputs the difference between the excitation signal voltage V_in and the operating voltage V_curve of the characteristic curve. The emitter of transistor Q1 is connected to the sampling resistor R. One end of the circuit is connected to the ground, the other end of the sampling resistor R1 is grounded, the collector of transistor Q1 is connected to the positive terminal of DC voltage source Vdc, the negative terminal of DC voltage source Vdc is grounded, the emitter of transistor Q1 is connected to the positive input terminal of voltage-controlled switch S1, the negative input terminal of voltage-controlled switch S1 is grounded, the positive output terminal of voltage-controlled switch S1 is connected to one end of the main load circuit, the negative output terminal of voltage-controlled switch S1 is connected to one end of gas discharge tube inductor Lg, the other end of gas discharge tube inductor Lg is connected to the cathode of diode D1, and the anode of diode D1 is grounded.

3. The PSpice circuit model for the HEMP response of a gas discharge tube according to claim 2, characterized in that: The sub-pulse source circuit includes a charging capacitor C0, a switch U1, an inductor L0, and a resistor R0; One end of the charging capacitor C0 is grounded, and the other end is connected to one end of the switch U1. The other end of the switch U1 is connected to one end of the inductor L0. The other end of the inductor L0 is connected to one end of the resistor R0. The other end of the resistor R0 is connected to one end of the sub-load circuit.

4. The PSpice circuit model for the HEMP response of a gas discharge tube according to claim 3, characterized in that: The sub-gas discharge tube circuit includes an inter-electrode capacitor Cg and an impedance Rg. One end of the inter-electrode capacitor Cg and one end of the impedance Rg are both connected to one end of the sub-load circuit, and the other ends of the inter-electrode capacitor Cg and the impedance Rg are both grounded.

5. The PSpice circuit model for the HEMP response of a gas discharge tube according to claim 4, characterized in that, The following steps are used to generate the action time-amplitude characteristic curve of the gas discharge tube: Step 1: Connect a load to the rear end of the gas discharge tube (3), and define the voltage across the load (5) after the gas discharge tube (3) discharges as the residual voltage after the gas discharge tube (3) discharges. Step 2: Output pulses to the gas discharge tube (3) with the output pulse voltage as the minimum operating voltage of the gas discharge tube (3), measure the residual voltage corresponding to the gas discharge tube (3) after multiple discharges, calculate and record the average value of the residual voltage amplitude and the average value of the half-width, define the average value of the residual voltage amplitude as the operating voltage amplitude of the gas discharge tube (3) under test, and the average value of the half-width as the operating time. Step 3: Gradually increase the output pulse voltage until it reaches the maximum output voltage of the pulse source. At each voltage level, calculate and record the action voltage amplitude and action time in the same way as in Step 2. At least 10 different pulse voltage levels should be taken. Step 4: Based on the action voltage amplitude and action time in Step 2 and Step 3, plot the "time-amplitude" curve of the gas discharge tube (3) with the action voltage amplitude as the vertical axis and the action time as the horizontal axis, and obtain the HEMP protection performance characterization of the gas discharge tube (3).

6. A PSpice circuit model for the HEMP response of a gas discharge tube according to any one of claims 2-5, characterized in that: The voltage source V1 is set to 1V; the DC voltage source Vdc is set to 200V; the sampling resistor R1 is set to 1Ω; and the reverse breakdown voltage of diode D1 is set to the arc voltage of the gas discharge tube.

7. The PSpice circuit model for the HEMP response of a gas discharge tube according to claim 6, characterized in that: The excitation source Vc is an editable excitation source Vc.

8. A simulation method for a PSpice circuit model of the HEMP response of a gas discharge tube according to any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Set the threshold for the difference between V_in and V_curve; start the first sub-circuit, the second sub-circuit, and the main circuit. The first sub-circuit and the second sub-circuit send the characteristic curve action voltage V_curve and the excitation signal voltage V_in to the gas discharge tube action simulation circuit, respectively. Step 2: The HEMP conduction environmental excitation waveform is applied to the main gas discharge tube circuit. If the difference between V_in and V_curve is greater than or equal to the set threshold, the gas discharge tube action simulation circuit is turned on, indicating that the gas discharge tube is activated and the circuit model protects the main load circuit. Conversely, if the gas discharge tube action simulation circuit is not turned on, it indicates that the gas discharge tube is not activated and the circuit model does not protect the main load circuit.

9. The simulation method for the PSpice circuit model of the HEMP response of a gas discharge tube according to claim 8, characterized in that: In step 1, the threshold value of the difference between V_in and V_curve is set as the starting voltage of transistor Q1; Step 2 is as follows: The HEMP conducted environmental excitation waveform is applied to the main gas discharge tube circuit. As the amplitude of the excitation signal V_in increases, if the difference between V_in and V_curve is greater than or equal to the start-up voltage of transistor Q1, the collector-emitter junction of transistor Q1 is turned on, and the voltage-controlled switch S1 is turned on, indicating that the gas discharge tube has activated. The current generated by the main pulse source circuit is quickly discharged to the ground terminal through the gas discharge tube inductor Lg, which protects the main load circuit. The voltage across the main load is the residual voltage after the gas discharge tube has activated. Conversely, if the difference is less than or equal to the start-up voltage, the voltage-controlled switch S1 will not be turned on, indicating that the gas discharge tube has not activated, and the circuit model has not protected the main load.

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