CN112737701A - Equipment for filtering interference in communication line in electromagnetic compatibility test - Google Patents
Equipment for filtering interference in communication line in electromagnetic compatibility test Download PDFInfo
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- CN112737701A CN112737701A CN202011600033.1A CN202011600033A CN112737701A CN 112737701 A CN112737701 A CN 112737701A CN 202011600033 A CN202011600033 A CN 202011600033A CN 112737701 A CN112737701 A CN 112737701A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/80—Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water
- H04B10/801—Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water using optical interconnects, e.g. light coupled isolators, circuit board interconnections
- H04B10/802—Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water using optical interconnects, e.g. light coupled isolators, circuit board interconnections for isolation, e.g. using optocouplers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/001—Measuring interference from external sources to, or emission from, the device under test, e.g. EMC, EMI, EMP or ESD testing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
- H04K3/00—Jamming of communication; Counter-measures
- H04K3/20—Countermeasures against jamming
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Abstract
An equipment for filtering interference in a communication line in an electromagnetic compatibility test belongs to the field of electromagnetic compatibility test detection. The equipment consists of an input system and an output system which are symmetrical, the two systems are connected through an optical fiber connected with the photoelectric switch, the input system adopts a metal frame and is grounded, and the shell of the output system adopts an insulating material and is suspended. The invention filters and completely isolates the electromagnetic interference on the communication line during the test process by various anti-electromagnetic compatibility conducted interference means, effectively ensures the safe operation of the computer and the network communication efficiency in the electromagnetic compatibility test environment, and provides reliable communication basis for the final electromagnetic compatibility test result.
Description
Technical Field
The invention belongs to the field of electromagnetic compatibility test detection, and particularly relates to equipment for filtering and monitoring electromagnetic interference on a communication line in a test environment.
Background
The power equipment needs to meet the requirements of electromagnetic compatibility immunity type tests according to standard requirements, in the tests, a computer is connected with a test sample through a network cable to carry out communication, and interference is applied to the test sample or a communication line so as to verify the running condition of the test sample in an interference environment.
In the process of applying interference to the tested sample, the interference often interferes to an Ethernet communication line through the tested sample, computer auxiliary equipment for monitoring the running state of the equipment by using the Ethernet can be interfered, and if a computer cannot resist the interference, communication errors can be caused, and an experimental result is influenced; communication interruption, failure to read test data, and the like may also occur, and the computer may be damaged by serious persons.
At present, most methods for solving the problems are to wind a magnetic ring on an Ethernet circuit, filter interference through the magnetic ring and reduce interference on a computer, but the method is not good enough in practical application process, firstly, the magnetic ring can only filter partial interference and can not completely isolate interference aiming at the computer; secondly, because the length of the network cable is short when the anti-interference magnetic ring is used, the number of turns of the wound magnetic ring is inconsistent, so that the anti-interference performance is greatly different.
Chinese patent application 201610830271.9 discloses an anti-interference device for testing electric energy meter, which is provided with a decoupling circuit on the power line without involving a communication line.
Disclosure of Invention
The invention aims to provide auxiliary equipment for isolating Ethernet communication interference, which can help a computer to monitor the running state of a tested sample more stably.
In order to achieve the purpose, the invention adopts the following technical scheme: the utility model provides an equipment of filtration communication line interference in anti-jamming test, communication line is the net twine, equipment includes input system and output system.
The input system comprises a case, a photoelectric switch and a power supply module are arranged in the case, an RJ45 interface and a power supply interface are arranged on the surface of the case, the RJ45 interface is connected with the photoelectric switch through a network cable with a shielding layer, a magnetic ring is wound on the connected network cable, the case is grounded through a metal frame, and the network cable shielding layer is reliably grounded through a metal network port.
The output system comprises a case, a photoelectric switch and a power supply module are arranged in the case, an RJ45 interface and a power supply interface are arranged on the surface of the case, the RJ45 interface and the photoelectric switch are connected through a network cable, the case is made of insulating materials, and equipment in the case is not grounded.
The photoelectric exchanger of the input system is connected with the photoelectric exchanger of the output system through optical fibers. The input system is connected with the tested equipment through a network cable, and the output system is connected with the computer through the network cable.
Furthermore, the power supply modules of the input system and the output system comprise a battery and a power supply management module for controlling the charging and discharging of the battery, and the battery is used for supplying power to the photoelectric switch in the test process.
Further, a network filter instead of a magnetic ring is arranged between the RJ45 interface of the input system and the photoelectric switch.
The input system adopts a metal conductive grounding frame by the whole structure, and the metal frame is provided with a grounding bolt and is used for safely grounding the system; switch organism ground connection, network filter ground connection, the RJ45 ethernet net gape of equipment adopts metal shield net gape and ground connection, power management module ground connection.
The battery is used for supplying power to the system switch in the test process, so that the alternating current circuit is prevented from generating interference, and the effect of isolating power supply circuit crosstalk is achieved.
The network filter filters the interference signal inside the network cable.
After the input system attenuates the interference, the interference of the input system is completely isolated through optical fiber communication, and effective signals are transmitted to an output system.
After the interference is isolated by the optical fiber, the output system is close to the computer, and the transmission of the interference to the computer is also reduced as much as possible, so that the output system is an insulation system, and a system shell is made of an insulation acrylic material.
The output system equipment is not grounded, and interference is prevented from being connected in series through a ground wire.
The invention filters and completely isolates the electromagnetic interference on the communication line during the test process by various anti-electromagnetic compatibility conducted interference means, effectively ensures the safe operation of the computer and the network communication efficiency in the electromagnetic compatibility test environment, and provides reliable communication basis for the final electromagnetic compatibility test result.
Drawings
FIGS. 1 and 2 are schematic diagrams of test environment arrangements;
FIG. 3 is a schematic structural view of the present invention;
FIG. 4 is a schematic diagram of a configuration of a network filter;
FIG. 5 is a connection diagram of a network filter;
FIG. 6 is a block diagram of a network filter;
FIG. 7 is a connection diagram of another network filter;
FIG. 8 is a block diagram of another network filter;
FIG. 9 is a schematic view of the multi-hole filtering magnetic ring and the winding threading;
FIG. 10 is a layout of the present invention;
fig. 11 is an external view of the present invention.
Detailed Description
The immunity type experiment of electromagnetic compatibility is generally divided into two types, as shown in fig. 1 and fig. 2.
Fig. 1 shows that interference is applied to an ethernet loop of a sample to be tested, whether the communication of the sample to be tested can resist the influence of the interference is checked, and normal communication and normal operation are maintained. In an experiment, 2kV pulse groups are applied to an Ethernet cable, a tested sample and a computer at two ends of the Ethernet cable both receive interference, but the test only aims at the tested sample, the computer is only auxiliary equipment, the performance of the computer is not checked, if interference filtering processing is not carried out, if the computer is not an industrial-grade or military-grade computer, the interference of the test is usually difficult to be suffered.
Fig. 2 illustrates the application of interference to the entire device.
In the process of applying interference to the tested sample, electromagnetic interference entering by crosstalk inevitably exists in the ethernet communication loop, and as mentioned above, normal communication of the auxiliary equipment (computer) is also affected.
Referring to fig. 3, a device for filtering interference in a communication line in an electromagnetic compatibility test is connected in the middle of a network cable between a device under test and a computer. The equipment consists of two symmetrical systems, namely an input system and an output system.
The input system comprises a case, a photoelectric switch and a power supply module are arranged in the case, an RJ45 interface and a power supply interface are arranged on the case, the RJ45 interface is connected with the photoelectric switch through a network cable with a shielding layer, a magnetic ring is wound on the connected network cable, the case is grounded through a metal frame, and the network cable shielding layer is reliably grounded through a metal network port.
The output system comprises a case, a photoelectric switch and a power supply module are arranged in the case, an RJ45 interface and a power supply interface are arranged on the case, the RJ45 interface and the photoelectric switch are connected through a network cable, the case is made of insulating materials, and equipment in the case is not grounded.
The photoelectric exchanger of the input system is connected with the photoelectric exchanger of the output system through optical fibers.
The input system is connected with the tested device through a network cable through an RJ45 interface, and the output system is connected with a computer through a network cable through an RJ45 interface.
Because the input system is close to an interference source, the electromagnetic compatibility influence needs to be eliminated, and the interference on the switch is reduced as much as possible. The input system metal frame is provided with a grounding bolt for system safety grounding.
The optical fiber is connected with the input system and the output system to further isolate the interference signal.
The output system is close to the computer, and the transmission of interference to the computer is also reduced as much as possible, so the output system is an insulating system, and the system shell is made of an insulating acrylic material.
The output system is not grounded and prevents crosstalk signals from the ground.
The power supply modules of the input system and the output system comprise batteries and a power supply management module for controlling the charging and discharging of the batteries, and the batteries are used for supplying power to the photoelectric switch in the test process and isolating power supply loop crosstalk.
The equipment uses an industrial grade photoelectric switch which is a DC48V direct current power supply; a 48V and 7Ah battery is used for supplying power to the equipment in the test process; the power management module controls the battery to discharge for the exchanger to use when performing a test, and charges the battery through the commercial power when the test is idle.
The technical measure is to filter out interference signals outside the network cable.
In order to attenuate and filter the interference signals from crosstalk into the network cable, a network filter is disposed between the RJ45 interface of the input system and the optical-electrical switch in this embodiment, as shown in fig. 4.
In this embodiment, two kinds of network filters are designed, as shown in fig. 5, fig. 6, fig. 7, and fig. 8, respectively.
The two network filters are provided with porous filtering magnetic rings, and a connecting line between the two RJ45 interfaces passes through the porous filtering magnetic rings.
In the process of electromagnetic compatibility detection, the conduction disturbance frequency band of a communication line is below 30MHz, and the ferrite material made of nickel-zinc can effectively inhibit the high-frequency interference of the frequency band, so that the nickel-zinc ferrite material magnetic ring is adopted. In order to reduce the cost and facilitate the installation, the magnetic ring is designed in a special structure, and the whole length is multiplied by the width by the height: 20mm 5mm 10mm, every row 4 of the front distribution diameter is 2mm totally 16 threading through-holes and is used for twining the communication line, input two rows of 8 communication lines totally about the net mouth, twine a circle in the magnetic ring and be used for filtering the high frequency conducted interference on every magnetic ring.
Each connection line, i.e. communication line, between two RJ45 interfaces uses 2 through holes of the multi-hole filtering magnetic ring to form a winding structure for the magnetic ring, as shown in 3 of fig. 9.
Referring to fig. 5 and 6, the network filter includes a housing, two RJ45 interfaces are disposed on the housing, and the filter housing and the two RJ45 interfaces are grounded.
The TX +, TX-, RX + and RX-ends of the two RJ45 interfaces are connected through a common-mode inductor, the nc end is connected with a 75-ohm resistor, and the resistor is grounded through a 1000pF capacitor.
Referring to fig. 7 and 8, the network filter includes a housing, two RJ45 interfaces are disposed on the housing, and the filter housing and the two RJ45 interfaces are grounded.
The TX +, TX-, RX + and RX-ends of the two RJ45 interfaces are connected through a common-mode inductor, the TX + and TX-connecting lines and the RX + and RX-connecting lines are also connected through gas discharge tubes, the gas discharge tubes are connected with bidirectional transient diodes, and the bidirectional transient diodes are grounded; the nc end is suspended.
The breakdown voltage of the gas discharge tube connection is 90V, and the breakdown voltage of the bidirectional transient diode is 72V.
The working principle of the filter shown in fig. 5 and 6 is as follows:
the filter mainly comprises: the input network port (network port 1), the porous magnetic ring, the common mode inductor, the output network port (network port 2), the discharge resistor and the like 5, and is mainly used for reducing the interference of high-frequency-band low-energy pulse groups.
The input network port and the output network port respectively adopt RJ45 sockets with metal shields, and a network transformer is not embedded in the socket and is mainly used for communication signal switching.
Common mode inductance: and after the preceding stage magnetic ring is subjected to high-frequency filtering, the magnetic ring is conducted into a common-mode inductor to continuously filter out common-mode interference. According to a common mode inductance minimum inductance calculation formula:L=X/(2πf)。
l is the minimum inductance, X is the loop impedance value, and f is the lowest signal attenuation frequency value.
The impedance of the RJ45 Ethernet interface transceiving loop is determined to be 10 omega, the value of the lowest signal attenuation frequency is set to be 5kHz, and the common mode minimum inductance is obtained by substituting the formula to be about 0.3 mH.
A bleeder resistance: the resistors R1, R2, R3 and R4 are mainly used for common-mode interference ground leakage of the NC ends of the input and output network ports, 4 resistors 75 omega are obtained according to experience of Bob Smith circuits, and the capacitance value is 1000 pF.
The working principle of the filter shown in fig. 7 and 8 is as follows:
the filter is additionally provided with a high-voltage bleeder circuit on the basis of the filter shown in figure 5, a bleeder resistor is removed, and an NC (numerical control) end in a communication network is suspended and is mainly used for reducing high-voltage large-current pulse interference.
The high-voltage discharge circuit is obtained by connecting the three-stage ceramic gas discharge tube and the bidirectional transient diode in series and grounding.
Because of the inert gas isolation function of the ceramic gas discharge tube, the bidirectional transient diode almost has no leakage current flowing, thereby slowing down the deterioration phenomenon of the diode caused by the leakage current flowing for a long time, and simultaneously effectively avoiding the problems of follow current and action sensitivity of the gas discharge tube during discharge due to the quick on-off capability of the diode.
The ceramic gas discharge tube adopts a direct current conducting voltage of 90V and a pulse discharge current of 10kA, and the bidirectional transient diode adopts a bidirectional device with a direct current transient conducting voltage of 36V, as shown in figure 7.
Referring to fig. 10 and 11, the input system and the output system are integrated, conducted interference is completely isolated, the panel is provided with the power interface, the network interface and the battery management module, and after the battery is fully charged by the equipment through the battery management module, the battery supplies power to the equipment in the test process, so that interference from the power line to the secondary ethernet switch is completely avoided in the test process.
Claims (9)
1. An equipment for filtering interference in a communication line in an electromagnetic compatibility test, the communication line being a network cable, characterized in that: the apparatus comprises an input system and an output system,
the input system comprises a case, a photoelectric switch and a power supply module are arranged in the case, an RJ45 interface and a power supply interface are arranged on the case, the RJ45 interface is connected with the photoelectric switch through a network cable with a shielding layer, a magnetic ring is wound on the connected network cable, the case adopts a metal frame and is grounded, and the network cable shielding layer is reliably grounded through a metal network port;
the output system comprises a case, a photoelectric switch and a power supply module are arranged in the case, an RJ45 interface and a power supply interface are arranged on the case, the RJ45 interface is connected with the photoelectric switch through a network cable, the case is made of insulating materials, and equipment in the case is not grounded;
the photoelectric switch of the input system is connected with the photoelectric switch of the output system through an optical fiber;
the input system is connected with the tested device through a network cable through an RJ45 interface, and the output system is connected with a computer through a network cable through an RJ45 interface.
2. The apparatus for filtering interference in a communication line in an emc test according to claim 1, wherein: the power supply modules of the input system and the output system comprise batteries and a power supply management module for controlling the charging and discharging of the batteries, and the batteries are used for supplying power to the photoelectric switch in the test process and isolating power supply loop crosstalk.
3. The apparatus for filtering interference in a communication line in an emc test according to claim 1, wherein: a network filter replacing a magnetic ring is arranged between an RJ45 interface of an input system and the photoelectric switch to attenuate interference signals.
4. The apparatus for filtering interference in a communication line in an emc test according to claim 3, wherein: the network filter comprises a shell, two RJ45 interfaces are arranged on the shell, and the shell of the filter and the two RJ45 interfaces are grounded; a filtering magnetic ring is arranged, and a connecting wire between the two RJ45 interfaces passes through the filtering magnetic ring;
the TX +, TX-, RX + and RX-ends of the two RJ45 interfaces are connected through a common-mode inductor, the nc end is connected with a 75-ohm resistor, and the resistor is grounded through a 1000pF capacitor.
5. The apparatus for filtering interference in a communication line in an emc test according to claim 3, wherein: the network filter comprises a shell, two RJ45 interfaces are arranged on the shell, and the shell of the filter and the two RJ45 interfaces are grounded; a filtering magnetic ring is arranged, and a connecting wire between the two RJ45 interfaces passes through the filtering magnetic ring;
the TX +, TX-, RX + and RX-ends of the two RJ45 interfaces are connected through a common-mode inductor, the TX + and TX-connecting lines and the RX + and RX-connecting lines are also connected through gas discharge tubes, the gas discharge tubes are connected with bidirectional transient diodes, and the bidirectional transient diodes are grounded; the nc end is suspended.
6. The apparatus for filtering interference in a communication line in an emc test according to claim 5, wherein: the direct current conducting voltage of the gas discharge tube is 90V, and the direct current transient conducting voltage of the bidirectional transient diode is 36V.
7. The apparatus for filtering interference in a communication line in an emc test according to claim 4 or 5, wherein: the filtering magnetic ring is a porous filtering magnetic ring made of nickel-zinc ferrite and is provided with 16 through holes.
8. The apparatus for filtering interference in a communication line in an emc test according to claim 7, wherein: each connecting wire between two RJ45 interfaces uses 2 through holes of the porous filtering magnetic ring to form a winding structure for the magnetic ring.
9. The apparatus for filtering interference in a communication line in an emc test according to claim 1, wherein: the input system and the output system are arranged as a whole.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202011600033.1A CN112737701A (en) | 2020-12-30 | 2020-12-30 | Equipment for filtering interference in communication line in electromagnetic compatibility test |
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| CN202011600033.1A CN112737701A (en) | 2020-12-30 | 2020-12-30 | Equipment for filtering interference in communication line in electromagnetic compatibility test |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113872689A (en) * | 2021-09-28 | 2021-12-31 | 上海市共进通信技术有限公司 | Method, apparatus, processor, and computer-readable storage medium for implementing radiation test adjustment processing for network ports |
| CN114900238A (en) * | 2022-05-10 | 2022-08-12 | 许昌开普检测研究院股份有限公司 | Isolation applying method for surge test of shielded communication line |
| CN117674768A (en) * | 2023-12-08 | 2024-03-08 | 中国航空工业集团公司沈阳飞机设计研究所 | A system-level conducted interference filter circuit design method based on black box model |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204104064U (en) * | 2014-07-31 | 2015-01-14 | 西北核技术研究所 | High-Power Microwave signal acquiring system under a kind of strong electromagnetic environment |
| CN204389022U (en) * | 2014-12-15 | 2015-06-10 | 上海市计量测试技术研究院 | EMC test intensity monitor system |
| CN205692164U (en) * | 2016-05-24 | 2016-11-16 | 深圳市赛盛技术股份有限公司 | A kind of RS422 interface electromagnetic compatible design circuit |
| CN207251819U (en) * | 2017-10-17 | 2018-04-17 | 吉林大学 | A kind of audio and video remote online monitoring system of anti-electromagnetic-radiation interference |
| CN107919892A (en) * | 2017-11-08 | 2018-04-17 | 深圳市沃特玛电池有限公司 | SPI communicates anti-jamming circuit |
| CN208424646U (en) * | 2018-06-27 | 2019-01-22 | 深圳市光域网络有限公司 | A kind of interchanger of high-grade antistatic |
| CN208623329U (en) * | 2018-01-19 | 2019-03-19 | 北京高普乐光电科技股份公司 | One kind having the compatible immunity to interference mould group of lightning protection EMC multifunction electromagnetic |
| CN209231424U (en) * | 2018-09-04 | 2019-08-09 | 智车优行科技（上海）有限公司 | The device of electromagnetic compatibility testing is carried out to the parts to be tested |
-
2020
- 2020-12-30 CN CN202011600033.1A patent/CN112737701A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204104064U (en) * | 2014-07-31 | 2015-01-14 | 西北核技术研究所 | High-Power Microwave signal acquiring system under a kind of strong electromagnetic environment |
| CN204389022U (en) * | 2014-12-15 | 2015-06-10 | 上海市计量测试技术研究院 | EMC test intensity monitor system |
| CN205692164U (en) * | 2016-05-24 | 2016-11-16 | 深圳市赛盛技术股份有限公司 | A kind of RS422 interface electromagnetic compatible design circuit |
| CN207251819U (en) * | 2017-10-17 | 2018-04-17 | 吉林大学 | A kind of audio and video remote online monitoring system of anti-electromagnetic-radiation interference |
| CN107919892A (en) * | 2017-11-08 | 2018-04-17 | 深圳市沃特玛电池有限公司 | SPI communicates anti-jamming circuit |
| CN208623329U (en) * | 2018-01-19 | 2019-03-19 | 北京高普乐光电科技股份公司 | One kind having the compatible immunity to interference mould group of lightning protection EMC multifunction electromagnetic |
| CN208424646U (en) * | 2018-06-27 | 2019-01-22 | 深圳市光域网络有限公司 | A kind of interchanger of high-grade antistatic |
| CN209231424U (en) * | 2018-09-04 | 2019-08-09 | 智车优行科技（上海）有限公司 | The device of electromagnetic compatibility testing is carried out to the parts to be tested |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113872689A (en) * | 2021-09-28 | 2021-12-31 | 上海市共进通信技术有限公司 | Method, apparatus, processor, and computer-readable storage medium for implementing radiation test adjustment processing for network ports |
| CN114900238A (en) * | 2022-05-10 | 2022-08-12 | 许昌开普检测研究院股份有限公司 | Isolation applying method for surge test of shielded communication line |
| CN117674768A (en) * | 2023-12-08 | 2024-03-08 | 中国航空工业集团公司沈阳飞机设计研究所 | A system-level conducted interference filter circuit design method based on black box model |
| CN117674768B (en) * | 2023-12-08 | 2024-05-31 | 中国航空工业集团公司沈阳飞机设计研究所 | System-level conducted interference filter circuit design method based on black box model |
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Application publication date: 20210430 |