Damping sinusoidal waveform parameter determination method for pulse current injection test

Abstract

The invention belongs to the technical field of high-altitude electromagnetic pulse tests, and particularly relates to a damping sinusoidal waveform parameter determination method for a pulse current injection test. Aiming at multiple groups of coupling current data obtained by a simulation or response test, constraint conditions which need to be met by the damping sine wave for the pulse current injection test are provided by taking strict examination as a principle, and the constraint conditions specifically comprise three aspects of amplitude, frequency spectrum and maximum rise rate. According to the method, the contradiction that a plurality of coupling waveforms exist in the electromagnetic pulse simulation or response test of the electronic equipment and one waveform needs to be defined in the pulse current injection test is effectively solved, and the aim of checking the vulnerability of the electromagnetic pulse of the electronic equipment based on the pulse current injection test is fully achieved.

Description

Technical Field

[0001] The invention relates to the technical field of high-attitude electromagnetic pulse (HEMP) testing, and in particular to a method for determining damped sinusoidal waveform parameters for a pulse current injection test. Background Art

[0002] High-altitude electromagnetic pulses can generate strong electromagnetic interference of the order of 10,000 volts per meter within a range of 1,000 kilometers, causing disorder in the operation of power electronic systems or even permanent damage, which is one of the major safety risks faced by important national infrastructure. Pulse current injection test is an important method for testing the vulnerability of electronic equipment to high-altitude electromagnetic pulses, and is one of the test items specified in standards such as GJB8848-2016 and GJB151B-2013.

[0003] Different from the irradiation test that simulates the electromagnetic environment of real scenes, the pulse current injection directly loads strong electromagnetic interference on the port of the electronic equipment to test its resistance to high-altitude electromagnetic pulses. The pulse current injection test has the advantages of easy control of test variables, low cost, and strong operability. However, as an indirect means, in order to obtain scientific and reliable test results, the requirements for test settings are high, especially the injection current waveform parameters. Standards such as MIL-188-125 provide reference methods for determining the injection test current waveform parameters. They mainly obtain the coupling current amplitude of the electronic equipment port through numerical simulation, continuous wave irradiation, low amplitude time domain irradiation, etc., and use double exponential, damped sine and other waveforms to implement pulse current injection tests for different objects such as cables and antennas.

[0004] In the actual operation of the above method, there is a problem that must be solved: the coupling current of the cable / antenna connected to the test device in the electromagnetic pulse environment is affected by multiple factors such as polarization direction and incident angle. Therefore, whether it is numerical simulation or response level test, at least two simulations or tests with two different polarization directions under two orthogonal incident directions are required to obtain multiple coupling current waveform data. Based on the feasibility and test efficiency of the pulse current injection test, it is necessary to comprehensively process the coupling current data under different test conditions to give an injection current waveform and its characteristic parameters. However, the current standard does not provide a specific method for processing multiple sets of waveform data. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problem that it is difficult to comprehensively process the coupling current data under different test conditions in the existing pulse current injection test to obtain an injection current waveform and its characteristic parameters to meet the needs of the pulse current injection test, and to provide a method for determining the damped sinusoidal waveform parameters for the pulse current injection test.

[0006] Assume that in an electromagnetic pulse simulation or response test of a certain device under different conditions, n coupling currents are obtained, which are I1(t), I2(t), I3(t), ..., I n (t). Then the damped sine waveform I PCI (t) should be larger than the above n coupling currents, so as to ensure that the pulse current injection test can fully evaluate the equipment under test.

[0007] Let I PCI (t) = kI0e -(πf0t) / Q sin(2πf0t), where k = 1 / e -π / (4Q) , kI0 is the peak value of the first cycle of the damped sine wave; f0 is the main frequency of the damped sine wave; Q is the waveform attenuation factor, which reflects the time required for kI0 to be reduced by half.

[0008] Comparing the waveform size in the time domain is traditionally done by comparing the peak value. However, in addition to the current peak value, the electromagnetic pulse effect of electronic equipment is also related to other effect norms such as the waveform spectrum and the waveform rise rate. For this reason, the present invention determines the damped sine waveform I PCI (t) There are three conditions that should be met. First, in the time domain, the damped sine waveform I PCI (t) is larger than the coupling current I1(t), I2(t), I3(t), ..., I n (t) amplitude; second, in the frequency domain, the damped sine waveform I PCI (t) The corresponding amplitude-frequency function I PCI (w) The amplitude at each frequency point is greater than the coupling current I1(t), I2(t), I3(t), ..., I n (t) The corresponding amplitude-frequency functions are F1(w), F2(w), F3(w), ..., F n (w); the third is the damped sine waveform I PCI The waveform rise rate of (t) is greater than that of the coupling current I1(t), I2(t), I3(t), ..., I n (t) is the rate of rise of the waveform.

[0009] It should be noted that for the damped sine waveform I PCI (t), under the above three conditions, other commonly used electromagnetic pulse effect norms, such as rectifier impact, energy root, damped sine waveform I PCI The norm values ​​of (t) are all greater than the coupling current I1(t)~I n The above constraints can fully ensure that the waveform to be injected is larger than each coupled current waveform.

[0010] To achieve the above purpose, the technical solution adopted by the present invention is:

[0011] A method for determining damped sine waveform parameters for pulse current injection test is characterized in that it comprises the following steps:

[0012] Step 1: Obtain n coupling currents of the device under test, which are I1(t), I2(t), I3(t), ..., I n (t); n ≥ 3;

[0013] Step 2: Based on the time reference t, the coupling currents I1(t), I2(t), I3(t), ..., I n (t) Interpolate and get the new coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t);

[0014] Step 3: Coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t) is Fourier transformed to obtain the coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns The spectrum of (t) is F1(w), F2(w), F3(w), ..., F n (w);

[0015] Step 4: Calculate the coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t) Maximum waveform rise rate R 1s , R 2s , R 3s , …, R ns ;

[0016] Step 5: Determine the damped sine wave I to be used in the pulse current injection test m (t) parameter value;

[0017] Step 6: By comparing the damped sine wave I determined by the parameter value in step 5 m (t) and coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t) amplitude, spectrum amplitude and maximum waveform rise rate, analyze the damped sine wave I m(t) Whether the preset constraints are met. If so, the minimum parameters that meet the preset constraints are obtained to determine the damped sine waveform I used in the pulse current injection test. PCI (t); If not, return to step 5 and re-determine the damped sine wave I to be used in the pulse current injection test m (t) parameter value until the preset constraints are met;

[0018] The preset constraints are:

[0019] 1) Damped sine wave I m The amplitude of (t) is greater than the coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns The amplitude of (t);

[0020] 2) Damped sine wave I m The spectrum amplitude of (t) is greater than the coupling current I within the preset range. 1s (t), I 2s (t), I 3s (t),…,I ns The spectrum amplitude of (t);

[0021] 3) Damped sine wave I m The maximum waveform rise rate of (t) is greater than the coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t) is the maximum waveform rise rate.

[0022] Furthermore, in step 2, the time reference t includes the total time t total and time interval Δt;

[0023] The total time t total ≥10μs, time interval Δt≤1ns.

[0024] Furthermore, in step 3, the spectrum F1(w), F2(w), F3(w), ..., F n The starting frequency f of (w) S =1 / t total , stop frequency f T =2 / Δt.

[0025] Further, in step 5, the damped sine wave I to be used in the pulse current injection test is determined in the following manner: m (t) Parameter value:

[0026] 1) The peak amplitude is taken as the coupling current I1(t), I2(t), I3(t), ..., I n (t) 3 times the maximum amplitude;

[0027] 2) The frequencies are F1(w), F2(w), F3(w), ..., F n (w) The average value of the frequency corresponding to the maximum amplitude of the three groups of coupling current spectrum in the spectrum;

[0028] 3) The waveform attenuation factor is 30.

[0029] The beneficial effects of the present invention are:

[0030] The present invention solves the contradiction that there are multiple coupled waveforms in the electromagnetic pulse simulation or response test of electronic equipment, while the pulse current injection test needs to clarify one waveform. The damped sine waveform determined by the method can fully test the electromagnetic pulse vulnerability of electronic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1( a ) is a time domain waveform diagram of a coupling current 1 according to an embodiment of the present invention;

[0032] FIG1( b ) is a time domain waveform diagram of the coupling current 2 in an embodiment of the present invention;

[0033] FIG1( c ) is a time domain waveform diagram of the coupling current 3 in an embodiment of the present invention;

[0034] Figure 2 1 is a time domain waveform diagram of three groups of coupling currents in an embodiment of the present invention (with the same time reference);

[0035] Figure 3 Spectra of three groups of coupling currents in the embodiment of the present invention;

[0036] Figure 4 is the damped sine wave I determined according to the initial parameter value in the embodiment of the present invention. m (t) and its amplitude envelope;

[0037] Figure 5 is the damped sine wave I in the embodiment of the present invention m (t) Comparison of amplitude envelope and time domain waveforms of three groups of coupling currents;

[0038] Figure 6 is the damped sine wave I in the embodiment of the present invention m (t) Comparison of the spectrum with the three sets of coupled current spectra;

[0039] Figure 7 is the damped sine waveform I in the embodiment of the present invention PCI (t) Comparison of amplitude envelope and time domain waveforms of three groups of coupling currents;

[0040] Figure 8 is the damped sine waveform I in the embodiment of the present invention PCI (t) Comparison of the spectrum with the three sets of coupling current spectra. DETAILED DESCRIPTION

[0041] In order to make the purpose, advantages and features of the present invention more clear, the following is a further detailed description of a method for determining damped sine waveform parameters for pulse current injection test proposed by the present invention in combination with the accompanying drawings and specific embodiments. According to the following specific implementation methods, the advantages and features of the present invention will be more clear.

[0042] Assume that in an electromagnetic pulse simulation or response test of a certain device under different conditions, three sets of coupling currents I1(t), I2(t), and I3(t) are obtained, as shown in Figure 1(a), (b), and (c).

[0043] The specific process of determining the pulse current injection test waveform of the device port in a damped sine waveform parameter determination method for a pulse current injection test in this embodiment is as follows:

[0044] (1) Preliminary processing of coupling current waveform.

[0045] Define a unified time base t, including the total time t total and time interval Δt, where the total time t total =100μs, time interval Δt=0.5ns.

[0046] Based on t, interpolate the coupling currents I1(t), I2(t), and I3(t) to obtain the new coupling current I 1s (t), I 2s (t), I 3s (t), the three have the same time base, which is convenient for subsequent data processing. The waveforms of the three sets of coupling currents are as follows: Figure 2 As shown, its maximum amplitude I max =262A.

[0047] (2) Using Fourier transform, we can get the coupling current I 1s (t), I 2s (t), I 3s The frequency spectra F1(w), F2(w), and F3(w) of (t). According to the setting of the time reference t, the starting frequency of each spectrum function f0 = 1 / t total =10kHz, end frequency f T =2 / Δt=1GHz. The amplitude-frequency curve expressed in decibels is as follows Figure 3 As shown, the frequency f corresponding to the maximum amplitude of the three sets of waveforms m1 、f m2 、f m3They are 11.2MHz, 9.9MHz and 12.2MHz respectively.

[0048] (3) Calculation of coupling current I 1s (t), I 2s (t), I 3s (t) Maximum waveform rise rate R 1s , R 2s , R 3s , 17.5A / ns, 10.2A / ns, and 8.2A / ns respectively.

[0049] (4) Determine the damped sine waveform I to be used in the pulse current injection test m (t) parameter value. The current amplitude is 3 times the maximum value of the three sets of coupling current I1(t), I2(t), and I3(t) waveforms. m0 =3×I max ≈800A; the frequency is the average value of the three sets of coupling current I1(t), I2(t), and I3(t) waveforms, f m =11MHz; the waveform attenuation factor takes a relatively large value, Q m =30. The damped sine wave I m (t), such as Figure 4 The black curve is shown. In addition, to facilitate amplitude comparison, the damped sine wave I m (t) The peak value of each cycle is obtained, and its amplitude envelope curve is obtained, such as Figure 4 The red curve shows

[0050] (5) By comparing the waveform and the value, the damped sine wave I determined by the above parameter values ​​is analyzed. m (t) Whether the following preset constraints are met. If so, the minimum parameters that meet the preset constraints are obtained to determine the damped sine waveform I used in the pulse current injection test. PCI (t); If not, return to step 4 and re-determine the damped sine wave I to be used in the pulse current injection test m (t) parameter value until the following preset constraints are met:

[0051] 1) Damped sine wave I m The amplitude of (t) is greater than the coupling current I 1s (t), I 2s (t), I 3s The amplitude of (t);

[0052] 2) Damped sine wave I m The spectrum amplitude of (t) is greater than the coupling current I within 300MHz. 1s (t), I 2s (t), I 3s The spectrum amplitude of (t);

[0053] 3) Damped sine wave I m The maximum waveform rise rate of (t) is greater than the coupling current I 1s (t), I 2s (t), I 3s (t) is the maximum waveform rise rate.

[0054] First, according to Figure 5 , we can see that the damped sine wave I m The amplitude of (t) is greater than the three sets of coupling current I 1s (t), I 2s (t), I 3s (t) amplitude; secondly, according to Figure 6 , we can see that the damped sine wave I m The spectrum amplitude of (t) is basically larger than the three sets of coupling current I 1s (t), I 2s (t), I 3s (t) spectrum amplitude, and it is fully satisfied within 300MHz; finally, the damped sine wave I is calculated m The maximum waveform rise rate of (t) is 56.7A / ns, which is greater than the three sets of coupling current I 1s (t), I 2s (t), I 3s (t) is the maximum waveform rise rate.

[0055] The damped sine wave I obtained in this embodiment according to the above preset constraints is PCI (t) The parameters are: I0 = 600A, Q = 18, f0 = 11MHz. The damped sine wave I determined by the above parameters n (t) Comparison of the amplitude envelope and the time domain waveforms of the three sets of coupling currents is shown in Figure 7 As shown; the spectrum comparison is as follows Figure 8 As shown; I PCI (t) The maximum waveform rise rate is 43.2A / ns, which is greater than the maximum waveform rise rates of the three groups of coupling currents.

Claims

1. A method for determining damped sinusoidal waveform parameters for pulse current injection test, characterized in that: The following steps are involved: Step 1: Obtain n coupling currents of the device under test, which are I1(t), I2(t), I3(t), ..., I n (t); n ≥ 3; Step 2: Based on the time reference t, the coupling currents I1(t), I2(t), I3(t), ..., I n (t) Interpolate and get the new coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t); Step 3: Coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t) is Fourier transformed to obtain the coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns The spectrum of (t) is F1(w), F2(w), F3(w), ..., F n (w); Step 4: Calculate the coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t) Maximum waveform rise rate R 1s , R 2s , R 3s , …, R ns ; Step 5: Determine the damped sine wave I to be used in the pulse current injection test m (t) parameter value; Step 6: By comparing the damped sine wave I determined by the parameter value in step 5 m (t) and coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t) amplitude, spectrum amplitude and maximum waveform rise rate, analyze the damped sine wave I m (t) Whether the preset constraint conditions are met. If so, the minimum parameter value that meets the preset constraint conditions is obtained to determine the damped sine waveform I finally used in the pulse current injection test. PCI (t); If not, return to step 5 and re-determine the damped sine wave I to be used in the pulse current injection test m (t) parameter value until the preset constraints are met; The preset constraints are: 1) Damped sine wave I m The amplitude of (t) is greater than the coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns The amplitude of (t); 2) Damped sine wave I m The spectrum amplitude of (t) is greater than the coupling current I within the preset range. 1s (t), I 2s (t), I 3s (t),…,I ns The spectrum amplitude of (t); 3) Damped sine wave I m The maximum waveform rise rate of (t) is greater than the coupling current I 1s (t), I 2s (t), I 3s (t),…,I ns (t) is the maximum waveform rise rate.

2. The method for determining damped sinusoidal waveform parameters for pulse current injection test according to claim 1, characterized in that: In step 2, the time reference t includes the total time t total and time interval Δt; The total time t total ≥10μs, time interval Δt≤1ns.

3. The method for determining damped sinusoidal waveform parameters for pulse current injection test according to claim 2, characterized in that: In step 3, the frequency spectra F1(w), F2(w), F3(w), ..., F n The starting frequency f of (w) S =1 / t total , stop frequency f T =2 / Δt.

4. A method for determining damped sinusoidal waveform parameters for a pulse current injection test according to any one of claims 1 to 3, characterized in that: In step 5, the damped sine wave I to be used in the pulse current injection test is determined as follows: m (t) Parameter value: 1) The peak amplitude is taken as the coupling current I1(t), I2(t), I3(t), ..., I n (t) 3 times the maximum amplitude; 2) The frequencies are F1(w), F2(w), F3(w), ..., F n (w) The mean of the frequencies corresponding to the maximum values ​​of the three groups of spectrum amplitudes in the spectrum; 3) The waveform attenuation factor is 30.

5. The method for determining damped sinusoidal waveform parameters for pulse current injection test according to claim 4, characterized in that: In step 6, the preset range is 300 MHz.

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