Diagnostic analysis method suitable for injection interference type immunity test

Abstract

The invention relates to an injection interference type immunity test diagnosis analysis method. The method comprises the following steps: S1, analyzing and judging the complexity of a to-be-tested diagnosis circuit; s2, analyzing and judging the power consumption type of the to-be-tested diagnosis circuit by taking the power of the to-be-tested diagnosis circuit as a reference; s3, manufacturing a radio frequency current RF for detection, attenuating the radio frequency energy by half through an attenuator by adopting a large current with the current of 200mA and the radio frequency energy of 5W-10W, and then processing through a blocking capacitor to obtain the radio frequency current RF for testing and diagnosis; s4, when the circuit is Ecns and Ecps, injecting a radio frequency current RF into a shielding layer or a circuit in the circuit to be tested and diagnosed, and synchronously observing the performance of the circuit in an injection state through auxiliary equipment so as to evaluate the anti-interference capability; and S5, when the circuit is Ecnc or Ecpc, injecting the radio frequency current into a shielding layer or a circuit in the to-be-tested diagnosis circuit through the set common-mode impedance voltage probe.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit diagnosis methods, and more specifically, to an analysis method for injection interference type immunity test diagnosis applicable to injection interference type immunity test diagnosis. Background Art

[0002] When existing tests detect problems with large current injection (BCI), the only useful information for analysis is sensitive cables, frequency bands, current levels, and failure manifestations. These information are necessary but not sufficient conditions for diagnosing and solving BCI problems. Therefore, the large current injection (BCI) problem cannot be solved 100%. For some unshielded or unfiltered electronic devices, solving the large current injection (BCI) problem completely depends on analyzing the interference path and the specific circuit affected. This requires the introduction of a more direct and efficient large current injection (BCI) analysis tool, which is necessary for diagnosing the immunity of electronic devices. It has low efficiency in evaluating and rectifying the performance of R & D products, high dependence on the standard laboratory test environment, and increases the risk of unqualified large current injection (BCI) immunity of products. Summary of the Invention

[0003] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide an analysis method for injection interference type immunity test diagnosis applicable to injection interference type immunity test diagnosis, so as to solve the technical problems mentioned in the background art.

[0004] To solve the above problems, the present invention adopts the following technical solutions.

[0005] An analysis method for injection interference type immunity test diagnosis, specifically as follows:

[0006] S1: Based on the number of simple circuits included in the circuit to be tested and diagnosed, analyze and judge the complexity of the circuit to be tested and diagnosed. Assume that the number of simple circuits included in the circuit to be tested and diagnosed is Noc. When Noc < 5, determine that the type of the circuit to be tested and diagnosed is a simple type, denoted as Ec ns , when Noc ≥ 5, determine that the type of the circuit to be tested and diagnosed is a complex type, denoted as Ec nc ;

[0007] S2: Based on the power of the circuit to be tested and diagnosed, analyze and judge the power consumption type of the circuit to be tested and diagnosed. Based on the total power consumption P of the circuit to be tested and diagnosed 总 , when P 总 < 500W, judge that the circuit to be tested and diagnosed is a low-power circuit, denoted as Ec ps , when P 总 ≥ 500W, judge that the circuit to be tested and diagnosed is a high-power circuit, denoted as Ec pc ;

[0008] S3: Generate a radio frequency current RF for detection. Use a large current of 200 mA and a radio frequency energy of 5 W - 10 W. After the radio frequency energy is attenuated by half through an attenuator, and then processed by a blocking capacitor, the radio frequency current RF for test diagnosis is obtained;

[0009] S4: According to the analysis results of S1 and S2, when the circuit is Ec ns and is Ec ps inject the radio frequency current RF into the shielding layer or the circuit in the circuit to be tested and diagnosed. Through an auxiliary device, synchronously observe the performance of the circuit in the injected state to evaluate the immunity;

[0010] S5: According to the analysis results of S1 and S2, when the circuit is Ec nc or is Ec pc inject the radio frequency current through the voltage probe with a common mode impedance set, into the shielding layer or the circuit in the circuit to be tested and diagnosed. Through an auxiliary device, synchronously observe the performance of the circuit in the injected state to evaluate the immunity.

[0011] Further, in S3, when using a large current of 200 mA and a radio frequency energy of 5 W, the attenuator is 150 kHz - 1000 MHz, 3 dB, and the blocking capacitor is 22 nF + 3 dB.

[0012] Further, in S3, when using a large current of 200 mA and a radio frequency energy of 10 W, the attenuator is 150 kHz - 1000 MHz, 10 dB, and the blocking capacitor is 22 nF + 10 dB.

[0013] Further, for the voltage probe with the common mode impedance used in 5, the type can be selected as 60 Ω - 150 Ω, 10 dB - 3 dB.

[0014] Compared with the prior art, the advantages of the present invention are:

[0015] 1. For a simple circuit, this method is very suitable for in-depth evaluation and analysis of the large current (BCI) performance of the hardware circuit, can discover potential problem points, and directly verify the rationality and effectiveness of the solution.

[0016] 2. For a complex circuit, the injection of radio frequency energy can be realized, which provides new ideas and methods for analyzing and solving conduction problems and conducted immunity problems. Brief Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the overall structure of an injection interference type immunity test and diagnosis analysis method of the present invention. Detailed Embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] Embodiment 1:

[0020] Please refer to Figure 1 , an injection interference type immunity test diagnosis and analysis method, specifically:

[0021] S1: Based on the number of simple circuits included in the circuit to be tested and diagnosed, analyze and judge the complexity of the circuit to be tested and diagnosed. Assume that the number of simple circuits included in the circuit to be tested and diagnosed is Noc. When Noc < 5, determine that the type of the circuit to be tested and diagnosed is a simple type, denoted as Ec ns , when Noc ≥ 5, determine that the type of the circuit to be tested and diagnosed is a complex type, denoted as Ec nc ;

[0022] S2: Based on the power of the circuit to be tested and diagnosed, analyze and judge the power consumption type of the circuit to be tested and diagnosed. Based on the total power consumption P of the circuit to be tested and diagnosed 总 , when P 总 < 500W, determine that the circuit to be tested and diagnosed is a low-power circuit, denoted as Ec ps , when P 总 ≥ 500W, determine that the circuit to be tested and diagnosed is a high-power circuit, denoted as Ec pc ;

[0023] S3: Produce a radio frequency current RF for detection. Use a large current of 200 mA and a radio frequency energy of 5W - 10W. After the radio frequency energy is attenuated by half through an attenuator, and then processed by a blocking capacitor, the radio frequency current RF for test diagnosis is obtained;

[0024] S4: According to the analysis results of S1 and S2, when the circuit is Ec ns and is Ec ps , use a large current of 200 mA and a radio frequency energy of 5W. The attenuator uses 150 kHz - 1000 MHz, 3 dB, and the blocking capacitor uses 22 nF + 3 dB to produce the radio frequency current RF. Inject the radio frequency current RF into the shielding layer or the circuit of the circuit to be tested and diagnosed, and synchronously observe the performance of the circuit in the injected state through auxiliary equipment to evaluate the immunity;

[0025] S5: According to the analysis results of S1 and S2, when the circuit is Ec ncOr it is Ec pc When it is Ec, a large current with a current of 200 mA and a radio frequency energy of 10 W is used. The attenuator uses 150 kHz - 1000 MHz, 10 dB, and the DC-blocking capacitor uses 22 nF + 10 dB to produce the radio frequency current RF. And through a voltage probe with a common-mode impedance of 60 Ω - 10 dB set, it is injected into the shielding layer or the circuit in the diagnostic circuit to be tested. By observing the performance of the circuit in the injected state synchronously through auxiliary equipment, the immunity evaluation is carried out.

[0026] Embodiment 2

[0027] Based on Embodiment 1, S1: Taking the number of simple circuits included in the diagnostic circuit to be tested as a benchmark, analyze and judge the complexity of the diagnostic circuit to be tested. Assume that the number of simple circuits included in the diagnostic circuit to be tested is Noc. When Noc < 5, it is determined that the type of the diagnostic circuit to be tested is a simple type, denoted as Ec ns When Noc ≥ 5, it is determined that the type of the diagnostic circuit to be tested is a complex type, denoted as Ec nc ;

[0028] S2: Taking the power size of the diagnostic circuit to be tested as a benchmark, analyze and judge the power consumption type of the diagnostic circuit to be tested. Taking the total power consumption P of the diagnostic circuit to be tested 总 When P 总 < 500 W, it is judged that the diagnostic circuit to be tested is a low-power circuit, denoted as Ec ps When P 总 ≥ 500 W, it is judged that the diagnostic circuit to be tested is a high-power circuit, denoted as Ec pc ;

[0029] S3: Produce the radio frequency current RF for detection. Use a large current with a current of 200 mA and a radio frequency energy of 5 W - 10 W. After the radio frequency energy is attenuated by half through the attenuator, and then processed by the DC-blocking capacitor, the radio frequency current RF for test diagnosis is obtained;

[0030] S4: According to the analysis results of S1 and S2, when the circuit is Ec ns and is Ec ps When it is, a large current with a current of 200 mA and a radio frequency energy of 10 W is used. The attenuator uses 150 kHz - 1000 MHz, 10 dB, and the DC-blocking capacitor uses 22 nF + 10 dB to produce the radio frequency current RF. The radio frequency current RF is injected into the shielding layer or the circuit in the diagnostic circuit to be tested. By observing the performance of the circuit in the injected state synchronously through auxiliary equipment, the immunity evaluation is carried out;

[0031] S5: According to the analysis results of S1 and S2, when the circuit is Ec nc or it is Ec pcWhen testing, a large current with a current of 200 mA and a radio frequency energy of 5 W is used. The attenuator is 150 kHz - 1000 MHz, 3 dB, and the DC-blocking capacitor is 22 nF + 3 dB to produce radio frequency current RF. It is injected into the shielding layer or the circuit in the diagnostic circuit to be tested through a voltage probe with a common-mode impedance of 150 Ω - 3 dB. The performance of the circuit under the injected state is synchronously observed through auxiliary equipment to evaluate the immunity.

[0032] The working process of the present invention is as follows:

[0033] 1. According to the method of direct injection in the standard conducted immunity IEC61000 - 4 - 6, injection is carried out on the shielding layer by using a 100 Ω coaxial resistor (50 Ω - 150 Ω converter). Referring to this method, after the direct injection of large current injection (BCI) is isolated by a DC-blocking capacitor, it can be used not only for the shielding layer but also for direct radio frequency injection into the circuit. Since the actual power of the 200 mA BCI injection is 2 W, a general 5 W small broadband power amplifier can meet the requirements of direct injection.

[0034] 2. Arrange the 200 mA BCI immunity problem analysis for a small circuit. The radio frequency energy output by the power amplifier is 5 W. After passing through a 3 dB attenuator (attenuating 2.5 W) and then through a DC-blocking capacitor, it can be safely injected into the low-voltage circuit. The performance of the circuit under the injected state is synchronously observed through auxiliary equipment to evaluate the immunity. This method is very suitable for in-depth evaluation and analysis of the BCI performance of the hardware circuit, can discover potential problem points, and directly verify the rationality and effectiveness of the solution.

[0035] 3. For larger circuits or systems, it is recommended to use the method of injecting through a common-mode voltage probe for direct injection into the cable port and the circuit interior. The EMC basic standard CISPR16 - 1 - 2 introduces a voltage probe for measuring the conducted common-mode voltage in some special cases, but the common-mode impedance of this standard voltage probe is 1500 ohms, which is not suitable for direct injection. By designing a voltage probe with a lower impedance, the injection of radio frequency energy can be achieved, which provides new ideas and methods for analyzing and solving conduction problems and conducted immunity problems.

[0036] Two different radio frequency voltage probes with different common-mode impedances and attenuation coefficients can be respectively applicable to the diagnostic analysis of different immunity levels, such as for injecting conducted immunity, large current injection (BCI), or radio frequency injection of radiated immunity, and can also be used for diagnosing problems of conducted and radiated emissions.

[0037] It can help EMC engineers quickly establish the large current injection (BCI) diagnostic ability at the R & D site in the early stage of development, effectively reducing the product design and R & D risks. Since the large current injection (BCI) is only a means of RF injection, and the injection of RF energy is the real purpose, we can reproduce the problems that occur in the large current injection (BCI) by directly injecting RF energy. Here, it is recommended to use the methods of direct injection and voltage probe injection to directly inject RF energy into the circuit, so that the diagnosis of the large current injection (BCI) problem can enter the PCB board level and circuit level, changing the problem analysis from a black box to a white box. This method is convenient, fast and low-cost, and plays a very important role in analyzing and identifying BCI problems and solving BCI problems in the early stage of design. It is very helpful for R & D EMC engineers to control EMC risks and efficiently carry out EMC design during the R & D process.

[0038] The above is only the preferred specific implementation mode of the present invention; however, the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its improved concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A diagnostic analysis method for injection interference immunity test, characterized in that: S1: Based on the number of simple circuits contained in the diagnostic circuit to be tested, analyze and determine the complexity of the diagnostic circuit to be tested. Assuming that the number of simple circuits contained in the diagnostic circuit to be tested is Noc, when Noc < 5, the type of the diagnostic circuit to be tested is determined to be a simple type and is counted as Ec. ns When Noc≥5, the diagnostic circuit type to be tested is determined to be a complex type and is used as Ec nc ; S2: Based on the power size of the diagnostic circuit to be tested, analyze and determine the power consumption type of the diagnostic circuit to be tested, and use the total power consumption P of the diagnostic circuit to be tested as the benchmark. 总 , when P 总 <500W is judged as a low power circuit and is used as Ec ps , when P 总 ≥500W is used as the Ec pc ; S3: Prepare the radio frequency current RF for detection, using a large current of 200mA and radio frequency energy of 5W-10W, attenuate the radio frequency energy by half through an attenuator, and then process it through a DC blocking capacitor to obtain the radio frequency current RF for test diagnosis; S4: According to the analysis results of S1 and S2, when the circuit is Ec ns And Ec ps When testing, the radio frequency current RF is injected into the shielding layer or circuit of the circuit to be tested and diagnosed, and the performance of the circuit under the injection state is synchronously observed by auxiliary equipment to evaluate the anti-interference capability; S5: According to the analysis results of S1 and S2, when the circuit is Ec nc Or Ec pc When the RF current is injected into the shielding layer or circuit of the diagnostic circuit to be tested through the voltage probe with the set common-mode impedance, the performance of the circuit under the injected state is synchronously observed through auxiliary equipment to evaluate the anti-interference capability.

2. A diagnostic analysis method for injection interference type immunity test according to claim 1, characterized in that: In S3, when a large current of 200 mA and RF energy of 5 W is used, the attenuator uses 150 kHz-1000 MHz and 3 dB, and the DC blocking capacitor uses 22 nF+3 dB.

3. A diagnostic analysis method for injection interference type immunity test according to claim 1, characterized in that: In S3, when a large current of 200 mA and 10 W of radio frequency energy is used, the attenuator uses 150 kHz-1000 MHz and 10 dB, and the DC blocking capacitor uses 22 nF+10 dB.

4. A diagnostic analysis method for injection interference type immunity test according to claim 1, characterized in that: The common mode impedance voltage probe used in 5 above can be selected from 60Ω-150Ω and 10dB-3dB.

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