A method and device for relaxing the limit of RE101 project in GJB151B

Abstract

The application provides a method and equipment for relaxing the limit value of RE101 project in GJB151B. Firstly, 25Hz-100kHz is divided into two frequency band ranges, 25Hz-30kHz and 30kHz-100kHz. Then, different relaxation methods are selected according to the current frequency band to obtain the relaxation limit value of the power line interface part in the RE101 project. Finally, corresponding relaxation conversion is carried out according to the corresponding CE type relaxation rule, which is consistent with the conduction relaxation algorithm, easy to understand and has strong engineering applicability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electronic testing, and particularly relates to a relaxation method for RE101 project limit value in GJB151B. BACKGROUND

[0002] With a large number of electronic equipment equipped in various weapon platforms, the problem of electromagnetic interference is increasingly prominent. In order to reduce the probability of platform electromagnetic interference, the overall, system and device three-level electromagnetic compatibility control mode is generally adopted in the type project. Each level needs to pass various electromagnetic emission and sensitivity tests to check whether it meets the predetermined electromagnetic compatibility performance requirements. Among the many examination projects, the 25Hz-100kHz magnetic field radiation emission project (RE101) is almost one of the examination projects.

[0003] RE101 is a project for checking whether the external magnetic field radiation of the device meets the standard limit value. According to the standard, the shell and its cable interface of the test piece shall be tested. Generally, the magnetic field radiation of the cable interface part is more obvious than that of the shell part, and it is easy to exceed the standard limit value. Among the cable interface parts exceeding the standard, the power cable is more likely to exceed the limit value, especially for high-power power generation and transformation equipment. According to the standard, the power cable cannot be shielded during the test, and even if the cable is shielded, the power cable needs to be stripped out. However, according to the electromagnetic field theory, when the current increases, a higher magnetic field will naturally be caused near the cable, and it shows a linear relationship with the current. In GJB151B, the CE101 project has adopted a related relaxation algorithm for different currents, but there is no related relaxation algorithm for the RE101 project of the power cable interface part. This situation is very common in engineering, and it is difficult for the equipment delivery unit to rectify it, thereby affecting the delivery of the equipment. There is an urgent need for a reasonable and easy-to-understand relaxation algorithm to properly evaluate the electromagnetic compatibility performance of the equipment. SUMMARY

[0004] In order to solve the problem that there is no related relaxation algorithm for the RE101 project of the power cable interface part in the standard, the application provides a relaxation method for the RE101 project limit value in GJB151B, which has clear ideas, is easy to understand, and has strong engineering applicability.

[0005] A relaxation method for the RE101 project limit value in GJB151B, different relaxation methods are selected to obtain the relaxation limit value of the power cable interface part in the RE101 project according to the different current frequency bands. When the frequency is 25Hz-30kHz, the relaxation limit value is obtained according to the CE101 relaxation algorithm in GJB151B. When the frequency is 30kHz-100kHz, the relaxation limit value is obtained according to the CE03 project relaxation algorithm in HJB34A.

[0006] Further, when the frequency is 25Hz-30kHz and the power line is an AC power line, the relaxation limit value W is obtained according to the following formula dB :

[0007] W dB = 20*log(I 10 I 基

[0008] wherein I 基 is the current in the AC power line;

[0009] When the frequency is 25Hz-30kHz and the power line is a DC power line, the relaxation limit value W is obtained according to the following formula dB :

[0010] W dB = 20*log(I ( 3A<I

[0011] wherein I 负载 is the current of the load on the DC power line.

[0012] Further, when I 负载 ≥ 185A, the relaxation limit value W dB = 35dB.

[0013] Further, when the frequency is 30kHz-100kHz, the relaxation limit value W is obtained according to the following formula dB :

[0014]

[0015] wherein I 负载 is the current of the load on the DC power line, f x is the relaxation frequency in the range of 30kHz-100kHz, f1 is the frequency of 15kHz, and d2 is the frequency of 2MHz.

[0016] A device for relaxing the limit value of RE101 project in GJB151B, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for relaxing the limit value of RE101 project in GJB151B according to any one of claims 1-4 when executing the computer program.

[0017] Advantages:

[0018] 1. The application provides a method for relaxing the limit value of RE101 project in GJB151B, first, 25Hz-100kHz is divided into 25Hz-30kHz and 30kHz-100kHz, a total of two frequency ranges, then different relaxation methods are selected according to the current frequency range to obtain the relaxed limit value of the power line interface part in the RE101 project, finally, the corresponding CE class relaxation rule is used for corresponding relaxation conversion, which is consistent with the conduction relaxation algorithm, easy to understand, and has strong engineering applicability.

[0019] 2. The application provides a method for relaxing the limit value of RE101 project in GJB151B, the relaxation algorithm divides 25Hz-100kHz into 25Hz-30kHz and 30kHz-100kHz, a total of two frequency ranges, then according to the power line type, the power line is divided into alternating current power line and direct current power line, finally, the corresponding CE class relaxation rule is used for corresponding relaxation conversion, which is easy to understand and has strong engineering applicability.

[0020] 3. The application provides a relaxation device for the limit value of RE101 project in GJB151B, the relaxation algorithm is clear in thinking, and can be easily integrated into the computer program of each detection unit, so that each detection unit has strong operability. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A flowchart of a method for relaxing the limit value of RE101 project in GJB151B is provided.

[0022] Figure 2 A frequency and current mapping relationship diagram of the CE03 project relaxation algorithm in HJB34A is provided.

[0023] Figure 3 A relaxed limit value diagram when the power line is an alternating current power line is provided.

[0024] Figure 4 A relaxed limit value diagram when the power line is a direct current power line is provided. DETAILED DESCRIPTION

[0025] In order to enable personnel in the technical field to better understand the scheme of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0026] The present invention provides a relaxation algorithm for the limits of the 25 Hz - 100 kHz magnetic field radiation emission project in GJB151B. The purpose is to inherit the existing CE101 relaxation algorithm in GJB151B and the CE03 relaxation algorithm in HJB34A. Based on electromagnetic field theory, actual test data, and engineering experience, 25 Hz - 100 kHz is divided into two frequency band ranges: 25 Hz - 30 kHz and 30 kHz - 100 kHz. Then, according to the electrical system type of the power line, it is subdivided into AC power lines and DC power lines. Finally, corresponding relaxation conversions are performed according to the corresponding CE class relaxation rules.

[0027] Specifically, as Figure 1 shown, a relaxation method for the limits of the RE101 project in GJB151B selects different relaxation methods according to different current frequency bands to obtain the relaxation limits at the power line interface part in the RE101 project. When the frequency is 25 Hz - 30 kHz, the relaxation limits are obtained according to the CE101 relaxation algorithm in GJB151B. When the frequency is 30 kHz - 100 kHz, the relaxation limits are obtained according to the CE03 project relaxation algorithm in HJB34A.

[0028] When the frequency is 25 Hz - 30 kHz and the power line is an AC power line, the relaxation limit W dB (unit: dB) is obtained according to the following formula:

[0029] W dB = 20 × log 10 I 基

[0030] where I 基 is the current in the AC power line, with the unit of ampere;

[0031] When the frequency is 25 Hz - 30 kHz and the power line is a DC power line, the relaxation limit W dB is obtained according to the following formula:

[0032] W dB = 20 × log(I load / 3) ( (3 A < I load < 185 A)

[0033] where I 负载 is the current of the load on the DC power line. When I 负载 ≥ 185 A, the relaxation limit W dB = 35 dB.

[0034] When the frequency is 30 kHz - 100 kHz, the relaxation limit W dB is obtained according to the following formula:

[0035]

[0036] where I 负载 is the current of the load on the DC power line, f x is the relaxed frequency point in the range of 30k-100kHz, unit Hz, f1 is Figure 2 the 15kHz frequency point in the above equation, and f2 is Figure 2 the 2MHz frequency point in the above equation.

[0037] The following further explains the limit relaxation algorithm of RE101 by taking a power line cable as an example.

[0038] (1) Assuming that the power line is an AC 50Hz and the current is 100A.

[0039] 25Hz-30kHz: W dB = 20*log 10 100 = 40dB

[0040] 30kHz-100kHz:

[0041]

[0042] The limit relaxation diagram after relaxation is shown in FIG. 1. Figure 3 After obtaining the relaxation value, for any one to-be-tested index in the RE101 project, assuming that the specified limit value is 25dB, and the relaxation limit value of the frequency band 25Hz-30kHz is calculated as 40dB at this time, if the index in the frequency band 25Hz-30kHz is calculated as greater than 65dB, it is considered that the to-be-tested index is unqualified, and if it is not greater than 65dB, it is considered that the to-be-tested index is qualified, thereby realizing relaxation.

[0043] (2) Assuming that the power line is a DC cable and the current is 100A.

[0044]

[0045] 30kHz-100kHz:

[0046]

[0047]

[0048] The limit relaxation diagram after relaxation is shown in FIG. 2. Figure 4

[0049] ​Therefore, the application can realize the relaxation algorithm of the limit value of the 25Hz-100kHz magnetic field radiation emission item (RE101) in GJB151B.

[0050] According to the disclosure of the application, other similar modes can be used to realize the specific RE101 relaxation algorithm, and the application is not limited to the specified algorithm.

[0051] Of course, the application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the application without departing from the spirit and essence of the application. However, these corresponding changes and modifications should belong to the protection scope of the appended claims of the application.

Claims

1. A method for relaxing the limits of RE101 item in GJB151B, characterized in that, Different relaxation methods are selected according to the different current frequency bands to obtain the relaxation limit of the power line interface in the RE101 project. When the frequency is 25Hz-30kHz, the relaxation limit is obtained according to the CE101 relaxation algorithm in GJB151B. When the frequency is 30kHz-100kHz, the relaxation limit is obtained according to the CE03 project relaxation algorithm in HJB34A.

2. The method for relaxing the limits of RE101 item in GJB151B as described in claim 1, characterized in that, When the frequency is 25Hz-30kHz and the power supply is AC, the relaxation limit W is obtained according to the following formula. dB : IN dB =20×log 10 AND 基 Among them, I 基 The current in the AC power line; When the frequency is 25Hz-30kHz and the power supply is a DC power supply, the relaxation limit W is obtained according to the following formula. dB : 3A 负载 <185A​ Among them, I 负载 This represents the current of the load on the DC power line.

3. The method for relaxing the limits of RE101 item in GJB151B as described in claim 2, characterized in that, When I 负载 When the value is ≥185A, the limit W is relaxed. dB =35dB.

4. A method for relaxing the limits of RE101 item in GJB151B as described in any one of claims 1 to 3, characterized in that, When the frequency is between 30kHz and 100kHz, the relaxation limit W is obtained according to the following formula. dB : Among them, I 负载 f is the current of the load on the DC power line. x f1 is a relaxed frequency range of 30k-100kHz, f2 is a 15kHz frequency, and f3 is a 2MHz frequency.

5. A device for relaxing the limits of item RE101 in GJB151B, characterized in that, It includes a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein when the processor executes the computer program, it implements the method for relaxing the limits of RE101 item in GJB151B as described in any one of claims 1-4.

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