A testing device and method for testing the coupling effect of HEMPs with injected equivalent irradiation on computer interfaces.

Abstract

This invention discloses a testing device for the coupling effect of HEMP (High-Altitude Nuclear Electromagnetic Pulse) on a computer interface under injected equivalent irradiation. Targeting a computer serial interface circuit coupled by high-altitude nuclear electromagnetic pulse (HEMP), electromagnetic simulation of the HEMP coupling scenario reveals that the actual coupling to the interface circuit is a decaying oscillating wave of a certain frequency and amplitude. This invention designs a testing method for the strong electromagnetic pulse coupling effect of HEMP on a communication interface based on the decaying oscillating wave source actually coupled to the interface. The method yields the interference conditions and damage threshold for the computer serial interface circuit, providing a reference for subsequent protection circuit design.

Description

Technical Field

[0001] This invention relates to the field of communication interface testing, and more specifically to a testing device for the coupling effect of HEMP with injected equivalent irradiation on a computer interface.

[0002] This invention also relates to a method for testing the coupling effect of HEMP to a computer interface by injecting equivalent irradiation. Background Technology

[0003] HEMP signals are a typical type of strong electromagnetic pulse. They have high instantaneous peak values ​​and steep pulse leading edges, which can cause serious damage to electronic equipment on the ground, much like lightning in nature. HEMP tests are divided into two types: injection tests and irradiation tests, each corresponding to different standards.

[0004] The electric field waveform formula for HEMP irradiation testing is specified by GJB151A, IEC 61000-2-9, and MIL-STD-461E standards. The waveform requirements for HEMP irradiation are a rise time of 2.3±0.5ns and a half-width at half-maximum (WHM) of 23±5ns. These parameters ensure the consistency and reliability of the test.

[0005] Due to limitations in experimental instruments and testing sites, it is currently very difficult to conduct high electromagnetic pulse (HMEP) irradiation tests on cables. Furthermore, the actual coupling waveforms of cables under real irradiation scenarios have not been thoroughly studied, leading to inconsistencies between the standard injection waveform and the actual coupling waveform. Therefore, the core of this technology is to investigate the actual coupling waveform of HMEP on computer communication cables. Based on this, an equivalent injection device for HEMP irradiation will be constructed to accurately study the coupling and damage effects of computer interconnect cables and interfaces under HEMP conditions, while reducing experimental complexity and cost.

[0006] Existing methods include:

[0007] 1. The principle of HEMP direct injection into computer communication cables is to utilize the electromagnetic field irradiated by a high-altitude nuclear electromagnetic pulse (HEMP) to directly inject an equivalent strong electromagnetic pulse signal into the cable of the device under test (DUT), thereby interfering with or damaging the hardware and software of the computer system. A high-altitude nuclear electromagnetic pulse is a short-duration, high-intensity electromagnetic pulse, with its energy primarily concentrated in the microwave frequency band. When a high-energy microwave pulse acts on a computer communication cable, it generates a strong electromagnetic induction effect, thereby interfering with or damaging the normal operation of the computer system. This method injects a simulated interference signal into the cable of the DUT while it is powered on, while simultaneously minimizing the impact of the injection device on the original signal channel and preventing the interference signal from interfering with other non-tested devices in the same power grid.

[0008] 2. The high-intensity electromagnetic pulse (HEMP) irradiation test for cables is a method used to evaluate the immunity and damage effects of electronic equipment when subjected to a HEMP attack. This test primarily involves irradiating the cable of the device under test with a simulated high-intensity electromagnetic pulse signal and observing its impact on the equipment. The core of this technology lies in using specialized equipment to generate a strong electromagnetic field similar to HEMP and directly irradiating these electromagnetic waves onto the communication cable under test. Through this high-intensity irradiation experiment, the performance of the cable under extreme conditions can be evaluated, and the cable design can be optimized accordingly, effectively improving the electromagnetic compatibility and reliability of the equipment.

[0009] The drawbacks of existing methods are:

[0010] Direct injection may fail to accurately simulate the irradiation environment in certain situations, resulting in coupling waveforms that do not match the actual HEMP waveforms, thus affecting the accuracy of the experimental results. The inaccuracy is mainly due to a lack of accurate analysis and judgment of the complex propagation and coupling process of electromagnetic waves, as well as interface impedance mismatch.

[0011] The disadvantage of HEMP (High Altitude Electromagnetic Pulse) irradiation cable testing lies in its high cost. This is mainly due to factors such as the high requirements for testing equipment, the difficulty in controlling the testing environment, the strict safety requirements, and the complexity of the test. Summary of the Invention

[0012] The purpose of this invention is to address the aforementioned problems by proposing a test method for injecting equivalent HEMP irradiation, based on obtaining the actual coupling waveform of HEMP-irradiated cables using electromagnetic simulation tools. This method investigates the coupling and damage effects of computer communication interface circuits by injecting coupling current with a specific attenuated oscillating waveform onto the line.

[0013] The technical solution adopted in this invention is as follows:

[0014] A device for testing the coupling effect of HEMP (Heat-Effect Hybrid Power) to a computer interface after injection of equivalent irradiation, comprising:

[0015] The attenuated oscillation source injection module is used to provide the test equipment with an equivalent HEMP irradiated cable coupling current;

[0016] The computer host is connected to the output of the attenuated oscillation wave source injection module via an interconnecting cable.

[0017] The rear end of the cable is connected to an interface board, and the interface board is connected to the computer host via a PCIe cable.

[0018] An oscilloscope, connected to a current clamp via an attenuator, the current clamp being connected to the cable;

[0019] A monitor, connected to the computer host, is used to display the status of the interface board.

[0020] Furthermore, the attenuated oscillation wave source injection module includes a current injection source and a pulse source, with the current source output terminal connected to the computer host interconnect cable.

[0021] Furthermore, the pulse source is used to adjust the current pulse size, and the current injection source is used to adjust the current frequency. The pulse source and the current injection source are used together to adjust the current to obtain a damped oscillation wave source.

[0022] This invention also provides a method for testing the coupling effect of HEMP to computer interface with injected equivalent irradiation, employing a test device for testing the coupling effect of HEMP to computer interface with injected equivalent irradiation, specifically implemented according to the following steps:

[0023] Obtain the equivalent HEMP-irradiated cable coupling current, i.e., the attenuated oscillation source;

[0024] Inject the attenuated oscillation source into the cable, observe the communication status of the interface board on the display screen, and save the oscilloscope data through the computer host.

[0025] After saving the oscilloscope data, disconnect the interface board from the cable, check whether the output pins of the interface board have a normal waveform and record it.

[0026] Repeat the above steps by adjusting the pulse source voltage to complete the test.

[0027] Furthermore, obtaining the equivalent HEMP-irradiated cable coupling current includes:

[0028] Simulation of coupling current in HEMP-irradiated cables:

[0029] The actual impedance at both ends of the cable is obtained, an electromagnetic field simulation cable model is established, and HEMP plane wave is used for irradiation to simulate the normal working state of the interface boards at both ends of the computer interconnect cable.

[0030] Adjusting cable parameters and determining the cable parameters, the cable coupling current under HEMP irradiation is simulated, and it is determined that the cable coupling current under HEMP irradiation is equivalent to a decaying oscillating wave source with a certain frequency and amplitude.

[0031] Furthermore, the cable parameters include cable length and cable height above the ground. The cable coupling current under HEMP irradiation is simulated by adjusting the cable length and cable height above the ground.

[0032] Furthermore, the coupling current of the equivalent HEMP-irradiated cable is calibrated prior to injection:

[0033] The output line of the current injection source is short-circuited, and the current on the short-circuit line is obtained by using a current clamp to obtain the irradiated cable coupling current that matches the frequency and peak value of the cable coupling current under HEMP irradiation.

[0034] Furthermore, the attenuated oscillating current generated by the calibrated current injection source was injected into the cable, the data communication status of the interface board on the display screen was observed, and the oscilloscope data was saved through the computer host.

[0035] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0036] 1. The present invention provides a testing device for the coupling effect of HEMP to computer interface by injecting equivalent irradiation, which has low testing cost and accurate injection method.

[0037] 2. Compared with the direct injection method, the HEMP irradiation equivalent injection test more accurately simulates the irradiation environment. Its equivalent injection waveform is the same as the waveform generated by the actual HEMP online coupling, which greatly increases the accuracy of the test results.

[0038] 3. Compared to HEMP irradiation cable testing, HEMP injection equivalent irradiation testing does not require generating electromagnetic pulse signals similar to the actual HEMP environment. Therefore, it does not require expensive and technically complex high-precision simulation systems, nor does it require dedicated laboratories and supporting facilities for HEMP irradiation testing, which greatly reduces the testing cost.

[0039] 4. The HEMP irradiation equivalent injection test is an effective evaluation method that can reveal the hazard mechanism and extent of HEMP to cables and interface boards. It is highly accurate and low-cost, providing a reference for HEMP protection design. Attached Figure Description

[0040] Figure 1 This is a flowchart of the equivalent injection test for HEMP irradiation of computer interconnect cables according to the present invention;

[0041] Figure 2 This is a time-frequency domain waveform diagram of the HEMP irradiation electric field of this invention;

[0042] Figure 3 This is an equivalent circuit diagram of the RS-232 interface board of the present invention;

[0043] Figure 4 This is a diagram of the field-line coupling model of the computer interconnect cable of the present invention;

[0044] Figure 5 This is a schematic diagram of the complete current waveform of the attenuated oscillation wave of the present invention;

[0045] Figure 6This is a simulation circuit diagram of the attenuated oscillating wave forming line of the present invention;

[0046] Figure 7 This is a schematic diagram of the layout of the short-circuit calibration test platform of the present invention;

[0047] Figure 8 This is a layout diagram of the short-circuit calibration test platform of the present invention;

[0048] Figure 9 The waveform diagram of the short circuit current when the RVSP cable of this invention is connected to the RS-232 board with a cable length of 1m and a height of 0.5m from the ground.

[0049] Figure 10 This is a schematic diagram of a test device for testing the coupling effect of HEMP to computer interface by injecting equivalent irradiation according to the present invention.

[0050] Figure 11 This is a diagram showing the on-site layout of the testing device of the present invention;

[0051] Figure 12 This is a normal output waveform diagram of the RS-232 board of this invention;

[0052] Figure 13 This is a waveform diagram of the RS-232 board of the present invention with no output.

[0053] Figure 14 The waveform diagram of the coupling current on the RVSP cable terminated on the RS-232 board of the present invention is shown as follows: the cable is 1m long and 0.01m above the ground.

[0054] Figure 15 The waveform diagram of the coupling current when the RVSP cable is terminated to the RS-232 board of the present invention has a cable length of 1m and a height of 0.5m above the ground. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings.

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0057] Due to limitations in experimental conditions and venues, and the complexity of experiments studying the coupling effects of HEMP-irradiated cables, in order to evaluate the impact of HEMP irradiation on interconnect cables and their termination interface boards, such as... Figure 1 As shown, the present invention employs a test method to simulate the irradiation effect of HEMP on cables by injecting a coupling current with an equivalent attenuated oscillating waveform on the line.

[0058] Simulation of equivalent injected signal for HEMP-irradiated cables:

[0059] (1) Parameter acquisition of simulation model

[0060] The expressions for HEMP injection and irradiation signals are as follows:

[0061] E(t)=E0k(e -αt -e -βt (1)

[0062] In the formula: k is the pulse electric field peak magnitude correction coefficient, E0 is the pulse field strength peak value, α is the pulse leading edge attenuation coefficient, and β is the pulse trailing edge attenuation coefficient.

[0063] According to MIL-STD-461E, the parameter E0 is determined to be 5 × 10. 4 V / m, k = 1.30, α = 4 × 10 7 / s, β=6×10 8 / s, substituting all parameters into equation (1) yields the time-domain and frequency-domain waveforms of HEMP irradiation as follows. Figure 2 As shown.

[0064] Obtaining the actual impedance of the communication interface:

[0065] To obtain the true impedance of the communication interface circuit, an injection test was first performed on the communication interface board to obtain its response waveform parameters. Then, an equivalent simulation circuit model was built in PSPICE software to obtain the test waveform. By combining simulation modeling with actual measurement, the simulation waveform and the test waveform were made consistent, thereby obtaining the equivalent circuit parameters of the HEMP coupling loop of the interface board. The impedance of the RS-232 interface board can then be obtained. Figure 3 As shown.

[0066] (2) Establishment of simulation model

[0067] After obtaining the actual impedance at both ends of the communication interface circuit (i.e., the cable) using the above method, the field-line coupling effect of the computer interface under HEMP irradiation was studied. In this experiment, a cable model was established using CST software. The cable was unshielded and unwrapped with a PVC sheath. HEMP plane wave irradiation was used to simulate the normal operating state of the interface boards at both ends of the computer interconnect cable. Figure 4 As shown. The detailed parameter settings are as follows:

[0068] 1) The HEMP irradiation source waveform has a rising edge of 2.3±0.5ns and a full width at half maximum (FWHM) of 23±5ns;

[0069] 2) The transmission line is parallel to the ground, the irradiation source uses a plane wave that is perpendicular to the ground, the E-field direction is parallel to the transmission line, and the worst-case coupling case is adopted;

[0070] 3) The cable radius is set to 0.5mm, based on the typical radius of computer interconnect cables;

[0071] 4) Set the grounding impedance at both ends of the cable as follows: Figure 4 The equivalent circuit impedance of the communication interface board shown is the actual impedance under normal operating conditions.

[0072] After the simulation model is established, the influence of cable length on the equivalent injected signal will be further studied:

[0073] (1) The effect of cable length on equivalent injected signal

[0074] With the cable height above the ground set to 1 cm and its length to 0.1 m, the simulation results of the cable coupling waveform are as follows. Figure 5 As shown;

[0075] With the cable height above the ground set to 1cm and lengths of 0.1m, 0.5m, 1m, 1.5m, and 2m, the coupling current data on the cable is shown in Table 1. Figure 5 As can be seen from the waveform and the data in the table, under HEMP wave irradiation and normal operating conditions, the line coupling current of the termination interface circuit board is a decaying oscillating wave with different peak values ​​and frequencies.

[0076] Table 1. Coupling current of RS-232 interface board with different cable lengths.

[0077]

[0078]

[0079] Within a 2m length of RS-232 interface cable, as the cable length increases, the frequency of the coupled current on the line continuously decreases. As the cable length continues to increase, the waveform of the coupled current is no longer a regular decaying oscillation wave, but becomes an irregular, periodically uncertain stray wave. Because the resistance, distributed capacitance, and distributed inductance of the cable itself change with the increase in cable length, the AC impedance of the cable changes accordingly. The AC impedance of the cable may have extreme values ​​or singularities, causing the current in the cable to change drastically or disappear. At this time, the frequency of the current waveform cannot be identified, and only a decaying envelope can be seen.

[0080] (2) The effect of cable height above ground on equivalent injected signal

[0081] Similar to the cable length model, for the establishment of cable models at different ground heights, a 1m length of commonly used computer interconnection cable in computer systems was selected for testing. A field-line coupling model was established in CST, with the following height parameter settings: to obtain the coupling law of cables at different ground heights, the cable length was set to 1m, and the ground heights were set to 0.01m, 0.02m, 0.05m, 0.1m, 0.2m, and 0.5m respectively.

[0082] Simulations were performed on the coupling current of the RS-232 interface board at different cable heights from the ground. The coupling current data are shown in Table 2. The data shows that under HEMP radiation, the coupling current of the RVSP cable corresponding to the RS-232 interface increases with increasing cable height from the ground, while the frequency decreases. Additionally, the peak pulse width and rise time also increase. Furthermore, Table 2 shows that the cable height from the ground has a more significant impact on the coupling current under normal operating conditions than the cable length. At a height of only 0.5m, the coupling current of several cables reaches approximately 70 amperes, which may damage the interface board.

[0083] Table 2 shows the coupling current of the RS-232 interface board at different ground heights for the corresponding cables.

[0084]

[0085]

[0086] The above simulations show that the cable coupling effect under HEMP irradiation is a decaying oscillating wave with a certain frequency and amplitude. Its frequency and amplitude have a certain correspondence with the cable length, cable height and interface impedance. Therefore, the core of the injection equivalent irradiation test method is to simulate this decaying oscillating wave and inject it into the interface circuit to obtain the true coupling effect of the interface.

[0087] Furthermore, after clarifying that the cable coupling effect under HEMP irradiation is a damped oscillating wave, the next step is to obtain the equivalent injected signal, i.e., the damped oscillating wave.

[0088] The principle behind the generation of damped oscillating waves is as follows: A dynamic circuit described by a second-order differential equation is a second-order circuit, with the RLC series circuit being one of the simplest. In an RLC series circuit, a damped oscillating discharge process occurs when the damping coefficient ξ < 1. The expression for the damping coefficient is shown below:

[0089]

[0090] The damping coefficient reflects the rate of energy loss in a system. Higher damping results in faster energy loss and quicker vibration decay. Specifically, when a system is underdamped, the circuit will oscillate, and the amplitude of the oscillation will gradually decrease over time. The decay rate and the frequency of the oscillation both depend on the damping coefficient. Therefore, the damping characteristics of a circuit can be controlled by adjusting the values ​​of the resistor, inductor, and capacitor.

[0091] The main circuit of the attenuated oscillating wave pulse current injection source uses a high-voltage transmission line as the pulse transmission line. The transmission line can be equivalent to a model of multiple LC networks connected in series. The DC power supply charges the main body of the LC network. The more LC network stages, the more accurate the simulation model and the smoother the output waveform. A coaxial cable with a characteristic impedance of 50Ω is selected as the transmission line. Figure 6 The simulation circuit shown can generate a damped oscillating wave output waveform.

[0092] After the damped oscillation wave is generated, it needs to be calibrated. The specific calibration process is as follows:

[0093] First, a damped oscillating wave injection module is constructed using a pulse source and a current injection source. This module can generate a damped oscillating wave with different frequencies and amplitudes. The pulse source is mainly responsible for adjusting the pulse size, while the current injection source is mainly responsible for adjusting the frequency. The output line of the current injection source is short-circuited, and the current on the short-circuit line is acquired using a current clamp to obtain the irradiated cable coupling current, which matches the frequency and peak value of the cable coupling current under HEMP irradiation. The schematic diagram of its short-circuit calibration test platform is shown below. Figure 7 As shown, the short-circuit calibration test platform built according to the schematic diagram is as follows: Figure 8 As shown.

[0094] Due to limitations of the experimental setup, the generated current frequency is between 30MHz and 90MHz. An equivalent irradiation injection test was conducted using RS-232 and the corresponding RVSP cable. According to the data in Tables 1 and 2, the waveforms of different frequencies that can be generated are shown in Tables 3 and 4 below.

[0095] Table 3 can generate the coupling current on cables of different lengths corresponding to RS-232 interfaces.

[0096]

[0097] Table 4 can generate the coupling current on the cable at different ground heights corresponding to the RS-232 interface.

[0098]

[0099]

[0100] Based on the data in Tables 3 and 4, the experimental steps in the actual experiment are as follows:

[0101] 1) According to Figure 8 Connect all devices and ground the pulse source and current injection source housings to prevent electric shock and electromagnetic interference.

[0102] 2) Adjust the oscilloscope settings, set the corresponding pulse width and trigger level, and set the trigger mode to rising edge trigger and single trigger;

[0103] 3) Trigger the pulse source to generate waveforms with corresponding amplitude and frequency, save the oscilloscope data, and set the clamping factor of the current clamp to 1, which means that the actual line current and the oscilloscope voltage reading are 1:1.

[0104] 4) By repeating the above steps, short-circuit currents corresponding to different line lengths and different line heights can be generated, i.e., damped oscillation sources.

[0105] The oscilloscope displays the obtained short-circuit current waveform, such as... Figure 9 As shown, this pulse source and current injection source can generate a current waveform that is consistent with the frequency and amplitude of the irradiated cable, which meets the requirements. Detailed data and corresponding pulse source injection voltage comparison tables are shown in Table 5 and Table 6.

[0106] Table 5 Comparison of Experimental Generated Current and Simulated Current for Different Line Lengths

[0107]

[0108]

[0109] Table 6 Comparison of Experimental Generated Current and Simulated Current at Different Line Heights

[0110]

[0111] After obtaining the equivalent injection signal, the solution of the present invention was tested, as follows:

[0112] A test device for testing the coupling effect of HEMP (Heated Electron Device) to a computer interface using injected equivalent irradiation is described. The current injection source output is connected to a computer interconnect cable, with an interface board at the rear of the cable. The interface board is connected to the host computer via a PCIe cable, and the host computer is connected to a monitor. The cable is connected to a current clamp, and the rear of the clamp is connected to an oscilloscope via a 20dB attenuator. The experimental setup schematic is shown below. Figure 10 As shown; a schematic diagram of the overall structure of the computer interconnection cable injection test platform built using the above-mentioned test apparatus is shown below. Figure 11 As shown.

[0113] After setting up the test setup, an injection test was performed on the RS-232 board. First, the computer host was connected to the unused RS-232 board via a PCIe cable. The board's debugging software was configured, and data was cyclically sent to the RS-232 board. The oscilloscope waveform was observed by connecting the probes (with the back end connected to an oscilloscope) to the RS-232 board's output pins. For example... Figure 12 As shown, injection is performed on the RVSP line connected to the RS-232 board, specifically following these steps:

[0114] 1) Connect all modules of the test device. Connect the monitor to the computer host, the pulse source to the current injection source, and the output of the current injection source to the computer interconnect cable. The back of the cable is the interface card. The interface card is connected to the computer host through the PCIe cable. The cable is connected to the current clamp. The back of the clamp is connected to the oscilloscope through the 20dB attenuator. Connect the outer shell of the pulse source and the current injection source to the ground wire to prevent electric shock and electromagnetic interference.

[0115] 2) Adjust the oscilloscope settings, set the corresponding pulse width and trigger level according to the simulated current, and set the trigger mode to rising edge trigger and single trigger;

[0116] 3) Change the cable length and set different cable heights according to the simulation scenario;

[0117] 4) Trigger the pulse source according to the current generated by the short circuit, inject it into the cable, observe the communication status of the board on the display screen, and save the oscilloscope data;

[0118] 5) Disconnect the board from the cable and use a multimeter to check if the output pins of the board have a normal waveform;

[0119] 6) Adjust the pulse source voltage and repeat the above steps to complete the test. The test results are shown in Tables 7 and 8.

[0120] Table 7. Results of Injection Tests on Computer Interconnect Cables of Different Lengths

[0121]

[0122] Table 8. Results of Injection Tests on Computer Interconnect Cables of Different Line Heights

[0123]

[0124] like Figure 13 The diagram shown is a schematic of the interface board when there is no output waveform. Figure 14 and Figure 15The diagram shows the coupling current after injecting the two sets of attenuated oscillating waves into the RVSP cable connected to the RS-232 board. It can be seen that the current on the line has become a stray and irregular waveform. Table 7 shows that at a height of 0.01m from the ground, changing the length of the RVSP cable has virtually no impact on the board. This is because the peak current coupled to the line by the attenuated oscillating wave is too small, and the peak pulse width is only tens of ns, resulting in a weak waveform. The HEMP polar pulse width is 500ns. Compared to the HEMP wave, the attenuated oscillating wave coupled to the line has a smaller pulse width and a shorter duration of action on the cable and interface board, thus temporarily preventing damage.

[0125] As shown in Table 8, the height above ground has a significant impact on the coupling current on the line and can easily cause interference and damage to the circuit board. With a line length of 1m and a height above ground of 0.1m, the circuit board has no waveform output. Figure 15 As shown; after restarting the computer, data transmission was performed on the board, and the board resumed output; after the cable was 0.5m above the ground, the display screen went black for about 3 seconds, and when the probes were used to measure the output pins of the board, the oscilloscope showed no output waveform. Restarting the computer allowed the board to output waveform again. It can be determined that the cable caused interference to the board when it was 0.1m above the ground. At this time, the voltage of the pulse source was above 1444V, and the coupling current on the line reached 12.6A.

[0126] In summary, the above experiments, combined with simulations, completed the equivalent injection experiment of HEMP irradiation on computer interconnect cables. Through the experiment, attenuated oscillating waves of different frequencies and peak values ​​were generated using existing equipment and injected into RVSP cables terminated with RS-232 interface cards. The experimental phenomena on the interface cards were observed, and damage was detected. It was found that the sensitivity of RVSP cables terminated with RS-232 interface cards to coupling current has a certain threshold at different lengths and ground heights. When the coupling current exceeds the threshold, the interface card will malfunction or be damaged, thus providing suggestions for cable placement. Although the experimental sample is limited and the experimental equipment has limitations, it was observed that increasing the cable length reduces the coupling current frequency. In addition, increasing the cable height above ground leads to an increase in coupling current and a decrease in frequency, thereby interfering with the interface cards, thus providing suggestions for cable placement in computer systems.

[0127] The HEMP irradiation equivalent injection test proposed in this invention is an effective evaluation method that can reveal the hazard mechanism and extent of HEMP to cables and interface boards, and provide a reference for HEMP protection design.

[0128] This article uses specific embodiments to illustrate the principles and implementation methods of the present invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A device for testing the coupling effect of HEMP (Heat-Equipped Particle) to a computer interface after injection of equivalent irradiation, characterized in that, include: The attenuated oscillating wave source injection module is used to provide the test device with an equivalent HEMP-irradiated cable coupling current, i.e., an attenuated oscillating wave source. Before injection, the equivalent HEMP-irradiated cable coupling current is calibrated: the output line of the current injection source is short-circuited, and the current on the short-circuited line is acquired through a current clamp to obtain the irradiated cable coupling current that matches the frequency and peak value of the cable coupling current under HEMP irradiation. The attenuated oscillating wave source injection module uses the attenuated oscillating wave current generated by the calibrated current injection source to inject into the cable. The computer host is connected to the output of the attenuated oscillation wave source injection module via an interconnecting cable. The rear end of the cable is connected to an interface board, and the interface board is connected to the computer host via a PCIe cable. An oscilloscope, connected to a current clamp via an attenuator, the current clamp being connected to the cable; A monitor, connected to the computer host, is used to display the status of the interface board.

2. The HEMP coupling effect testing device for computer interface based on injected equivalent irradiation according to claim 1, characterized in that, The attenuated oscillation wave source injection module includes a current injection source and a pulse source, and the output end of the current source is connected to the computer host interconnection cable.

3. The HEMP coupling effect testing device for computer interface based on injected equivalent irradiation according to claim 2, characterized in that, The pulse source is used to adjust the current pulse size, and the current injection source is used to adjust the current frequency. The pulse source and the current injection source are used together to adjust the current to obtain a damped oscillation wave source.

4. A method for testing the coupling effect of a HEMP to a computer interface under injected equivalent irradiation, comprising using the HEMP to computer interface coupling effect testing apparatus according to any one of claims 1 to 3, characterized in that, The specific steps are as follows: Obtain the equivalent HEMP-irradiated cable coupling current, i.e., the attenuated oscillating wave source; Inject the attenuated oscillation source into the cable, observe the status of the interface board on the display screen, and save the oscilloscope data through the computer host. After saving the oscilloscope data, disconnect the interface board from the cable, check whether the output pins of the interface board have a normal waveform and record it. Repeat the above steps by adjusting the pulse source voltage to complete the test.

5. The method for testing the coupling effect of HEMP to a computer interface with injected equivalent irradiation according to claim 4, characterized in that, The process of obtaining the equivalent HEMP-irradiated cable coupling current includes: Simulation of coupling current in HEMP-irradiated cables: The actual impedance at both ends of the cable is obtained, an electromagnetic field simulation cable model is established, and HEMP plane wave is used for irradiation to simulate the normal working state of the interface boards at both ends of the computer interconnect cable. Adjusting cable parameters and determining the cable parameters, the cable coupling current under HEMP irradiation is simulated, and it is determined that the cable coupling current under HEMP irradiation is equivalent to a decaying oscillating wave source with a certain frequency and amplitude.

6. The method for testing the coupling effect of HEMP to a computer interface with injected equivalent irradiation according to claim 5, characterized in that, The cable parameters include cable length and cable height above the ground. The cable coupling current under HEMP irradiation is simulated by adjusting the cable length and cable height above the ground.

7. The method for testing the coupling effect of HEMP to a computer interface with injected equivalent irradiation according to claim 4, characterized in that, The oscilloscope data was injected into the cable using the attenuated oscillating current generated by the calibrated current injection source. The communication status of the interface board on the display screen was observed, and the oscilloscope data was saved through the computer host.

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