Device and method for testing coupling effect of HEMP injected with equivalent irradiation on computer interface

Abstract

The invention discloses a device for testing the coupling effect of an HEMP injected with equivalent irradiation on a computer interface, and aims at a computer serial interface circuit under high-altitude nuclear electromagnetic pulse HEMP coupling, the coupling scene of the HEMP is subjected to electromagnetic simulation to obtain a damped oscillation wave which is actually coupled to the interface circuit and has a certain frequency and amplitude, and the coupling effect of the HEMP on the computer interface is tested. According to the communication interface HEMP strong electromagnetic pulse coupling effect testing method based on the damped oscillation wave source actually coupled to the interface, the interference condition and the damage threshold value for a computer serial interface circuit are obtained, and reference is provided for subsequent protection circuit design of the computer serial interface circuit.

Description

Technical Field

[0001] The invention relates to the field of communication interface testing, and in particular to a device for testing the coupling effect of a HEMP injected with equivalent radiation on a computer interface.

[0002] The invention also relates to a method for testing the coupling effect of HEMP injected with equivalent radiation on a computer interface. Background Art

[0003] HEMP signal is a typical strong electromagnetic pulse with a high instantaneous peak value and a steep pulse front. It will cause serious damage to electronic equipment on the ground, which is very similar to natural lightning. HEMP tests are divided into injection tests and irradiation tests, which correspond to different standards.

[0004] The electric field waveform formula for the HEMP irradiation test is specified by the GJB151A specification, IEC 61000-2-9 specification, and MIL-STD-461E specification. The HEMP irradiation waveform requires the rise time to be within the range of 2.3±0.5ns and the half-width to be within the range of 23±5ns. These parameters ensure the consistency and reliability of the test.

[0005] Due to the limitations of test instruments and test sites, it is very difficult to implement strong electromagnetic pulse irradiation tests on cables. At the same time, the actual coupling waveform of cables under real irradiation scenarios has not been studied in detail, and there is a discrepancy between the standard injection waveform and the actual coupling waveform. Therefore, the core of this technology is to explore the real coupling waveform of HMEP on computer communication cables, and on this basis, build an equivalent injection device for HEMP irradiation, and accurately study the coupling and damage effects of computer interconnect cables and interfaces under HEMP environment while reducing the complexity and cost of the experiment.

[0006] Existing methods include:

[0007] 1. The principle of HEMP direct injection into computer communication cable technology is to use the electromagnetic field irradiated by high-altitude nuclear electromagnetic pulses to directly inject equivalent strong electromagnetic pulse signals into the cables of the device under test to interfere with or damage the hardware and software of the computer system. High-altitude nuclear electromagnetic pulses are short-duration, high-intensity electromagnetic pulses, and their energy is mainly concentrated in the microwave frequency band. When high-energy microwave pulses act on computer communication cables, they will produce a strong electromagnetic induction effect, thereby interfering with or damaging the normal operation of the computer system. This method injects simulated interference signals into the cables of the device under test in the powered-on working state. At the same time, it is necessary to reduce the impact of the injection device on the original signal channel to prevent the interference signal from interfering with other non-tested devices in the same power grid.

[0008] 2. The strong electromagnetic pulse irradiation test of cables is a test method used to evaluate the immunity and damage effects of electronic equipment when subjected to strong electromagnetic pulse attacks. This test mainly irradiates the cables of the device under test with simulated strong electromagnetic pulse signals to observe their impact on the equipment. The core of this technology is to use special equipment to generate a strong electromagnetic field similar to HEMP, and directly irradiate these electromagnetic waves onto the communication cables to be tested. Through this high-intensity irradiation experiment, the performance of cables under extreme conditions can be evaluated, and the design of cables can be optimized accordingly, effectively improving the electromagnetic compatibility and reliability of the equipment.

[0009] The disadvantages of the existing methods are:

[0010] In some cases, the direct injection method may not accurately simulate the irradiation environment, resulting in the coupling waveform not being consistent with the actual HEMP waveform, thus affecting the accuracy of the test results. The main reason for the inaccuracy is the lack of accurate analysis and judgment of the complex propagation and coupling process of electromagnetic waves, as well as interface impedance mismatch and other reasons.

[0011] The disadvantage of high-altitude nuclear electromagnetic pulse HEMP irradiation cable test is its high test cost, which is mainly due to factors such as high test equipment requirements, difficulty in test environment control, strict safety requirements and test complexity. Summary of the invention

[0012] The purpose of the present invention is: to address the above-mentioned problems, the present invention proposes a test method for injecting equivalent HEMP irradiation on the basis of obtaining the real coupling waveform of HEMP irradiated cables using electromagnetic simulation tools, and explores the coupling and damage effects of computer communication interface circuits by injecting coupling currents of specific attenuated oscillation waveforms on the line.

[0013] The technical solution adopted by the present invention is as follows:

[0014] A device for testing the coupling effect of HEMP on computer interface injected with equivalent radiation, comprising:

[0015] Attenuated shock wave source injection module, used to provide equivalent HEMP irradiation cable coupling current for the test device;

[0016] A computer host, the computer host is connected to the output end of the attenuated shock wave source injection module through an interconnection cable;

[0017] The rear end of the cable is connected to an interface card, and the interface card is connected to the computer host via a PCIE line;

[0018] an oscilloscope connected to a current caliper via an attenuator, wherein the current caliper is connected to the cable;

[0019] A display is connected to the computer host and 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, and the output end of the current source is connected to the computer host interconnection 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 to jointly adjust the current to obtain an attenuated oscillation wave source.

[0022] The present invention also provides a method for testing the coupling effect of HEMP injected with equivalent radiation on a computer interface, using a device for testing the coupling effect of HEMP injected with equivalent radiation on a computer interface, and is specifically implemented in the following steps:

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

[0024] Inject the attenuated shock wave 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 pin of the interface board has a normal waveform and record it;

[0026] Adjust the pulse source voltage and repeat the above steps to complete the test.

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

[0028] HEMP irradiates the cable coupling current to simulate:

[0029] The real impedance at both ends of the cable is obtained, an electromagnetic field simulation cable model is established, and HEMP plane waves are used for irradiation to simulate the normal working state of the interface cards at both ends of the computer interconnection cable;

[0030] The cable parameters are adjusted to determine the cable parameters. The cable coupling current under HEMP irradiation is simulated to determine that the cable coupling current under HEMP irradiation is equivalent to an attenuated oscillation wave source with a certain frequency and a certain amplitude.

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

[0032] Furthermore, the equivalent HEMP irradiation cable coupling current is calibrated before injection:

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

[0034] Furthermore, the attenuated oscillating wave current generated by the calibrated current injection source is used to inject into the cable, the data communication status of the interface board on the display screen is observed, and the oscilloscope data is 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. A device for testing the coupling effect of HEMP on computer interface by injecting equivalent irradiation in the present invention has low testing cost and accurate injection method.

[0037] 2. Compared with the direct injection method, the HEMP irradiation equivalent injection test simulates the irradiation environment more accurately. 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 with the HEMP irradiation cable test, the HEMP injection equivalent irradiation test does not need to generate electromagnetic pulse signals similar to the actual HEMP environment, so it does not require expensive and technically complex high-precision simulation systems, nor does it require special laboratories and supporting facilities to conduct HEMP irradiation tests, which greatly reduces the test costs.

[0039] 4. HEMP irradiation equivalent injection test is an effective evaluation method that can reveal the mechanism and extent of HEMP damage to cables and interface boards. It has high accuracy and low cost, and provides a reference for HEMP protection design. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of the equivalent injection test of HEMP irradiated computer interconnection cables of the present invention;

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

[0042] Figure 3 The RS-232 interface card equivalent circuit diagram of the present invention;

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

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

[0045] Figure 6A circuit diagram for simulating the formation of a decaying oscillating wave according to the present invention;

[0046] Figure 7 The schematic diagram of the short circuit calibration test platform of the present invention is shown;

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

[0048] Fig. 9 This is the short-circuit current waveform diagram of the RVSP cable of the present invention being terminated to the RS-232 card with a line length of 1m and a height of 0.5m from the ground;

[0049] Fig.10 It is a schematic diagram of a device for testing the coupling effect of HEMP on computer interface injected with equivalent radiation according to the present invention;

[0050] Fig.11 It is a site layout diagram of the test device of the present invention;

[0051] Fig.12 This is the normal output waveform of the RS-232 board of the present invention;

[0052] Fig.13 The RS-232 board card of the present invention has no output waveform;

[0053] Fig.14 This is a coupling current waveform diagram of the line where the RVSP cable of the present invention is terminated to the RS-232 card with a line length of 1m and a height of 0.01m from the ground;

[0054] Fig.15 This is the coupling current waveform diagram of the RVSP cable of the present invention being terminated to the RS-232 board with a line length of 1m and a height of 0.5m from the ground. DETAILED DESCRIPTION

[0055] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0056] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0057] Due to the limitations of test conditions and test sites, as well as the complexity of the coupling effect research test of HEMP irradiated cables, in order to evaluate the impact of HEMP irradiation on interconnected cables and their termination interface cards, such as Figure 1 As shown, the solution of the present invention adopts a test method for simulating the radiation effect of HEMP on the cable by injecting a coupling current of an equivalent attenuated oscillation waveform on the line.

[0058] HEMP irradiation cable equivalent injection signal simulation:

[0059] (1) Acquisition of simulation model parameters

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

[0061] E(t)=E0k(e -αt -e -βt )(1)

[0062] Where: k is the pulse electric field peak correction coefficient, E0 is the pulse field intensity peak, α is the pulse front attenuation coefficient, and β is the pulse trailing edge attenuation coefficient.

[0063] Determine each parameter E0=5×10 according to MIL-STD-461E 4 V / m, k = 1.30, α = 4 × 10 7 / s, β=6×10 8 / s, substituting all parameters into formula (1), the time domain waveform and frequency domain waveform of HEMP irradiation are as follows Figure 2 shown.

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

[0065] In order to obtain the real impedance of the communication interface circuit, the communication interface card is first injected with an injection test to obtain its response waveform parameters. Then, an equivalent simulation circuit model is established in the PSPICE software to obtain the test waveform. By combining simulation modeling with actual measurement, the simulation waveform is made consistent with the test waveform to obtain the equivalent circuit parameters of the HEMP coupling loop of the interface card. The impedance of the RS-232 interface card can be obtained as follows: Figure 3 shown.

[0066] (2) Establishment of simulation model

[0067] After obtaining the real impedance of the communication interface circuit, i.e. the two ends of the cable, according to the above method, the field line coupling effect of the computer interface under HEMP irradiation is studied. In this experiment, the cable model is established using CST software. The cable has no shielding layer and is wrapped with a PVC coat. HEMP plane waves are used for irradiation to simulate the normal working state of the interface cards at both ends of the computer interconnection cable. Figure 4 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 half-height width of 23±5ns;

[0069] 2) The transmission line is parallel to the ground, the irradiation source uses a plane wave incident vertically on the ground, the E field direction is parallel to the transmission line, and the worst coupling situation is adopted;

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

[0071] 4) Set the ground impedance at both ends of the cable to Figure 4 The equivalent circuit impedance of the communication interface board shown is the actual impedance under normal working conditions.

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

[0073] (1) Effect of cable length on equivalent injection signal

[0074] Assuming the cable height from the ground is 1cm and the length is 0.1m, the cable coupling waveform simulation results are as follows Figure 5 As shown;

[0075] The cable height from the ground is set to 1 cm, and the length is set to 0.1m, 0.5m, 1m, 1.5m, and 2m. The online coupling current data is shown in Table 1. Figure 5 It can be seen from the waveform in the figure and the data in the table that under the irradiation of the HEMP wave, under normal working conditions, the online coupling current of the termination interface circuit board card is an attenuated oscillation wave with different peak values ​​and different frequencies.

[0076] Table 1 Coupling current of RS-232 interface card corresponding to different cable lengths

[0077]

[0078]

[0079] For RS-232 interface cables within 2m in length, as the cable length increases, the frequency of the coupled current on the line continues to decrease. As the cable length continues to increase, the waveform of the coupled current is no longer a regular attenuated oscillation wave, but becomes an irregular, spurious wave with uncertain period. As the cable length increases, the resistance, distributed capacitance, distributed inductance and other parameters of the cable itself change, causing the AC impedance of the cable to change accordingly. The AC impedance of the cable may have extreme values ​​or singularities, causing the current in the cable to change dramatically or disappear. At this time, the frequency of the current waveform cannot be identified, and only an attenuated envelope can be seen.

[0080] (2) Effect of cable height from the ground on equivalent injection signal

[0081] Similar to the cable length model, for the establishment of cable models at different heights above the ground, the computer interconnection cable length of 1m commonly used in computer systems was selected for testing, and the field line coupling model was established in CST, and its height parameters were set as follows: obtain the cable coupling law at different heights above the ground, set the cable length to 1m, and set the heights above the ground to 0.01m, 0.02m, 0.05m, 0.1m, 0.2m, and 0.5m respectively.

[0082] The online coupling current of the RS-232 interface card corresponding to different heights from the ground is simulated, and the online coupling current data is shown in Table 2. It can be seen from the data in the table that under the irradiation of HEMP waves, the magnitude of the coupling current of the RS-232 interface corresponding to the RVSP cable increases with the increase of the height of the cable from the ground, and the frequency decreases with the increase of the height from the ground. In addition, the peak pulse width and rise time also increase continuously. And from the data in Table 2, it can be seen that compared with the cable length, the height of the cable from the ground has a stronger impact on the online coupling current under normal working conditions. When the height from the ground is only 0.5m, the coupling current of several cables reaches about 70 amperes, which may cause damage to the interface card.

[0083] Table 2 Coupling current of RS-232 interface card corresponding to the cable at different heights from the ground

[0084]

[0085]

[0086] From the above simulation, it can be concluded that the cable coupling effect under HEMP irradiation is an attenuated oscillation wave with a certain frequency and amplitude. Its frequency and amplitude have a certain corresponding relationship with the line length, line height and interface impedance. Therefore, the core of the injection equivalent irradiation test method is to simulate this attenuated oscillation wave and inject it into the interface circuit to obtain the real coupling effect of the interface.

[0087] Furthermore, after clarifying that the cable coupling effect under HEMP irradiation is an attenuated shock wave, the next step is to obtain the equivalent injection signal, namely the attenuated shock wave.

[0088] The generation principle of the attenuated oscillation wave is as follows: the dynamic circuit described by the second-order differential equation is a second-order circuit, in which the RLC series circuit is one of the simplest second-order circuits; in the RLC series circuit, a process of attenuated oscillation discharge will occur when the damping coefficient ξ<1, and the damping coefficient expression is shown in the following formula:

[0089]

[0090] The size of the damping coefficient reflects the speed of energy loss in the system. The greater the damping, the faster the energy loss and the faster the vibration decay. Specifically, when the system is in an underdamped state, the circuit will experience oscillations, and the amplitude of the oscillation will gradually decrease over time. The decay rate and the frequency of the oscillation depend on the size of the damping coefficient. Therefore, by adjusting the values ​​of resistance, inductance and capacitance, the damping characteristics of the circuit can be controlled.

[0091] The main circuit of the attenuated oscillation 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 groups of LC networks in series. The DC power supply charges the main body of the LC network. The more LC network levels there are, the more accurate the simulation model is, and the smoother the output waveform is. The transmission line selects a coaxial cable with a characteristic impedance of 50Ω, such as Figure 6 The line simulation circuit shown can form a decaying oscillation wave output waveform.

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

[0093] First, the pulse source and current injection source are used to form an attenuated oscillation wave source injection module. The attenuated oscillation wave source injection module can generate an attenuated oscillation wave with different frequencies and amplitudes. The pulse source is mainly responsible for adjusting the pulse size, and 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 obtained through the current calibrator to obtain the irradiated cable coupling current that is consistent with the cable coupling current frequency and peak value under HEMP irradiation. The schematic diagram of the short-circuit calibration test platform is shown below: Figure 7 As shown in the figure, the short circuit calibration test platform built according to the schematic diagram is as follows Figure 8 shown.

[0094] Due to the limitation of the test equipment, the current frequency that can be generated is between 30MHz and 90MHz. RS-232 and the corresponding RVSP cable are used to carry out the irradiation injection equivalent test. According to the data in Table 1 and Table 2, the different frequency waveforms that can be generated are shown in Table 3 and Table 4.

[0095] Table 3 can generate the coupling current of RS-232 interface corresponding to different cable lengths

[0096]

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

[0098]

[0099]

[0100] In the actual experiment, according to the data in Table 3 and Table 4, the test steps are as follows:

[0101] 1) According to Figure 8 Connect all devices and connect the pulse source and current injection source housing to the ground wire 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 a waveform with corresponding amplitude and frequency, and save the oscilloscope data. The clamp factor of the current clamp is 1, which means that the actual line current and the oscilloscope voltage reading are 1:1;

[0104] 4) Repeat the above steps to generate short-circuit currents corresponding to different line lengths and different line heights, that is, attenuated oscillation sources.

[0105] The oscilloscope displays the resulting short-circuit current waveform, such as Fig. 9 As shown, this pulse source and current injection source can generate a current waveform consistent with the frequency and amplitude of the irradiated cable, meeting the requirements. The detailed data and the corresponding pulse source injection voltage comparison table are shown in Table 5 and Table 6.

[0106] Table 5 Comparison of generated current and simulated current in different line length tests

[0107]

[0108]

[0109] Table 6 Comparison of generated current and simulated current in different line height tests

[0110]

[0111] After the acquisition of the equivalent injection signal is completed, the solution of the present invention is tested and experimented, as follows:

[0112] A test device for the coupling effect of HEMP injected with equivalent radiation on computer interface, the output of the current injection source is connected to the computer interconnection cable, the rear end of the cable is an interface card, the interface card is connected to the host through the PCIE line, and the host is connected to the display; the cable is connected to the current caliper, and the rear end of the caliper is connected to the oscilloscope through a 20dB attenuator. The test layout principle diagram is as follows Fig.10 As shown; the overall schematic diagram of the computer interconnect cable injection test platform built using the above test device is as follows Fig.11 shown.

[0113] After building the test device, perform an injection test on the RS-232 board. First, connect the computer host to the unused RS-232 board through the PCIE line, set up the board debugging software, send data to the RS-232 board in a loop, and use a test lead (connected to an oscilloscope at the back end) to connect the RS-232 board output pin to observe the oscilloscope waveform, such as Fig.12 As shown, inject the RVSP line connected to the RS-232 board. The specific steps are as follows:

[0114] 1) Connect the various modules of the test device, connect the display to the computer host, connect the pulse source to the current injection source, connect the output end of the current injection source to the computer interconnection cable, the rear end of the cable is the interface card, the interface card is connected to the computer host through the PCIE line, the cable is connected to the current caliper, and the rear end of the caliper is connected to the oscilloscope through a 20dB attenuator; connect the pulse source and the current injection source housing 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) Replace cables of different lengths and set different cable heights according to the simulation scenario;

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

[0118] 5) Disconnect the board and cable, and use a test lead to check whether the board output pin has 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 Table 7 and Table 8.

[0120] Table 7 Injection test results of computer interconnect cables with different cable lengths

[0121]

[0122] Table 8 Injection test results of computer interconnection cables with different line heights

[0123]

[0124] like Fig.13 The figure shows the schematic diagram when the interface board has no output waveform. Fig.14 and Fig.15The schematic diagram of the coupling current after the two selected groups of attenuated oscillation waves are injected into the RVSP cable terminated with the RS-232 board. It can be seen that the current on the line has become a stray and irregular waveform. As can be seen from Table 7, when the distance from the ground is 0.01m, changing the length of the RVSP cable has basically no effect on the board. This is because the peak current of the attenuated oscillation wave coupled to the line is too small, and the peak pulse width is tens of ns, the waveform is not strong, and the pulse width of the HEMP polarity pulse is 500ns. Compared with the HEMP wave, the attenuated oscillation wave coupled to the line has a smaller pulse width, and the duration of the cable and interface board is shorter, so it cannot cause damage to them temporarily.

[0125] It can be seen from Table 8 that the height from the ground has a great influence on the coupling current on the line, and it will easily cause interference and damage to the board. When the line length is 1m and the height from the ground is 0.1m, the board has no waveform output. Fig.15 As shown in the figure, after restarting the computer, the board is transmitted data, and the board resumes output; after the height from the ground reaches 0.5m, the display screen is black for about 3s, the output pin of the board is measured with a test lead, and the oscilloscope has no output waveform. After restarting the computer, the board can also output the waveform again. It can be judged that the cable causes interference to the board after the height from the ground is 0.1m. At this time, the voltage of the pulse source is above 1444V, and the coupling current on the line reaches 12.6A.

[0126] In summary, the above-mentioned experiments were combined with simulations to complete the equivalent injection test of HEMP irradiated computer interconnection cables. Through the experiment, the existing device was used to generate attenuated oscillation waves with different frequencies and peaks to inject into the RVSP cable terminated with the RS-232 interface board, and the test phenomenon of the interface board was observed to detect whether it was damaged. It was found that the RVSP cable terminated with the RS-232 interface board had a certain threshold for the sensitivity to the coupling current at different lengths and different heights from the ground. When the coupling current exceeded the threshold, the interface board would work abnormally or be damaged, thus obtaining suggestions for the placement of the cable. Although the test samples were limited and the test device had limitations, it was observed that an increase in cable length would reduce the frequency of the coupling current. In addition, an increase in the height of the cable from the ground would lead to an increase in the coupling current and a decrease in the frequency, thereby interfering with the interface board, thus making suggestions for the placement of cables in the computer system.

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

[0128] The principles and implementation methods of the present invention are described in this article using specific embodiments. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A device for testing the coupling effect of HEMP on computer interface injected with equivalent radiation, characterized in that: include: Attenuated shock wave source injection module, used to provide equivalent HEMP irradiation cable coupling current for the test device; A computer host, the computer host is connected to the output end of the attenuated shock wave source injection module through an interconnection cable; The rear end of the cable is connected to an interface card, and the interface card is connected to the computer host via a PCIE line; an oscilloscope connected to a current caliper via an attenuator, wherein the current caliper is connected to the cable; A display is connected to the computer host and is used to display the status of the interface board.

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

3. A device for testing the coupling effect of HEMP on computer interface injected with equivalent radiation 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 to jointly adjust the current to obtain an attenuated oscillation wave source.

4. A method for testing the coupling effect of HEMP injected with equivalent radiation on a computer interface, using a device for testing the coupling effect of HEMP injected with equivalent radiation on a computer interface as claimed in any one of claims 1 to 3, characterized in that: Please follow the steps below to implement: Obtain the equivalent HEMP irradiated cable coupling current, i.e. the attenuated shock wave source; Inject the attenuated shock wave source into the cable, observe the interface board status 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 pin of the interface board has a normal waveform and record it; Adjust the pulse source voltage and repeat the above steps to complete the test.

5. A method for testing the coupling effect of HEMP on computer interface by injection of equivalent radiation according to claim 4, characterized in that: The obtaining of equivalent HEMP irradiated cable coupling current comprises: HEMP irradiates the cable coupling current to simulate: The real impedance at both ends of the cable is obtained, an electromagnetic field simulation cable model is established, and HEMP plane waves are used for irradiation to simulate the normal working state of the interface cards at both ends of the computer interconnection cable; The cable parameters are adjusted to determine the cable parameters. The cable coupling current under HEMP irradiation is simulated to determine that the cable coupling current under HEMP irradiation is equivalent to an attenuated oscillation wave source with a certain frequency and a certain amplitude.

6. A method for testing the coupling effect of HEMP on computer interface by injection of equivalent radiation according to claim 5, characterized in that: The cable parameters include cable length and cable height from the ground. The cable coupling current under HEMP irradiation is simulated by adjusting the cable length and the cable height from the ground.

7. A method for testing the coupling effect of HEMP on computer interface by injection of equivalent radiation according to claim 5, characterized in that: Calibration of equivalent HEMP irradiation cable coupling current before injection: The output line of the current injection source is short-circuited, and the current on the short-circuited line is obtained by a current clamp to obtain the irradiated cable coupling current that is consistent with the frequency and peak value of the cable coupling current under HEMP irradiation.

8. A method for testing the coupling effect of HEMP on computer interface by injection of equivalent radiation according to claim 7, characterized in that: Use the attenuated oscillating wave current generated by the calibrated current injection source to inject into the cable, observe the communication status of the interface board on the display screen, and save the oscilloscope data through the computer host.

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