CN115792427A - Cable coupling interference effect test system and method - Google Patents
Cable coupling interference effect test system and method Download PDFInfo
- Publication number
- CN115792427A CN115792427A CN202211333718.3A CN202211333718A CN115792427A CN 115792427 A CN115792427 A CN 115792427A CN 202211333718 A CN202211333718 A CN 202211333718A CN 115792427 A CN115792427 A CN 115792427A
- Authority
- CN
- China
- Prior art keywords
- cable
- test
- coupling
- frequency
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The invention discloses a cable coupling interference effect testing system and method. The device comprises a simulation cable coupling effect testing device; the simulation cable coupling effect testing device comprises a simulation shielded cable, a receiver, a first cable interface box and a second cable interface box; the simulation cable coupling effect testing device is laid in a site interference cable within 10cm, and the coupling length is more than 3m; at least 1 of the first and second cable interface boxes adopts a coaxial cable test structure; the coaxial cable test structure is used for measuring the induced current of the shielding layer and the coupling voltage of the core wire of the analog shielding cable; the receiver is connected to the core coupling voltage interface and the current probe in the current test chamber to reflect the coupling interference effect level. The method can accurately obtain the induced current of the shielding layer and the induced voltage of the cable core wire generated in the external field environment, thereby evaluating the electromagnetic coupling interference level of the external field electromagnetic environment on the cable and providing theoretical data support for the electromagnetic compatibility of the external field test.
Description
Technical Field
The invention relates to the technical field of electromagnetic testing, in particular to a cable coupling interference effect testing system and a method.
Background
The novel power generation equipment used at the present stage has dense cables inside and numerous power transformation equipment, belongs to high-power generation, generally speaking, electromagnetic environment is complicated, and sensitive equipment on site is easily influenced by electromagnetic interference, particularly, the problem of interference of high voltage and large current is very prominent when a full-electric mode is adopted.
Disclosure of Invention
In view of this, the present invention provides a cable coupling interference effect testing system and method, which can accurately obtain a shielding layer induced current and a cable core induced voltage generated in an external field environment, so as to evaluate an electromagnetic coupling interference level formed by the external field electromagnetic environment on a cable, and provide a theoretical data support for an external field test electromagnetic compatibility.
In order to solve the technical problem, the invention is realized as follows:
a cable coupling interference effect test system comprises a simulation cable coupling effect test device; the simulation cable coupling effect testing device comprises a simulation shielded cable, a first cable interface box, a second cable interface box and a receiver A;
the simulation cable coupling effect testing device is laid in a site interference cable within 10cm and simulates actual situation arrangement; the effective coupling length between the simulated shielded cable and the field interference cable is larger than 3m, and the actual situation arrangement is simulated; the simulation shielded cable is a cable with the same model or structural characteristics as the tested cable;
at least 1 of the first cable interface box and the second cable interface box adopts a coaxial cable test structure; the coaxial cable test structure is used for measuring the induced current of the shielding layer of the analog shielding cable and the coupling voltage of the core wire;
the receiver A is used for connecting a core wire coupling voltage interface led out from a voltage test cabin in the coaxial cable test structure and connecting a current probe in the current test cabin through a measuring coaxial cable so as to reflect the coupling interference effect level.
Preferably, the system further comprises an external field cable coupling effect testing device;
the external field cable coupling effect testing device comprises a current probe and a receiver B; the receiver B is connected with a current probe through a measuring coaxial cable, the current probe is arranged on the tested cable, and a shielding sheath is arranged; the distance between the position of the current probe installed on the tested cable and the equipment end is less than 1m; the shielding sheath is made of a metal shielding material with shielding effectiveness not less than 30dB in a set testing frequency range, and a current probe with a size adapted to the shielding sheath is installed; and the receiver B measures the induction current data of the shielding layer of the tested cable, and converts the obtained induction current data of the shielding layer by transferring impedance data to obtain the coupling voltage data of the cable core wire and reflect the coupling interference effect level.
Preferably, the system further comprises a data recording device;
the data recording device receives data input of the receivers A and B, and the induced current data of the shielding layer of the tested cable obtained by the external field cable coupling effect testing device is subjected to frequency treatment by taking the abscissa as the frequency and the ordinate as the current amplitude logarithm value to form a first shielding layer induced current frequency spectrum curve; converting the cable core wire coupling voltage data of the tested cable obtained by the outfield cable coupling effect testing device by taking an abscissa as frequency and an ordinate as a voltage amplitude logarithm value to form a first cable core wire coupling voltage frequency spectrum curve;
forming a second shielding layer induced current frequency spectrum curve by using the shielding layer induced current data of the simulated shielding cable obtained by the simulated cable coupling effect testing device and taking the abscissa as the frequency and the ordinate as the current amplitude logarithm value; forming a second cable core wire coupling voltage frequency spectrum curve by using the core wire coupling voltage data of the simulated shielded cable obtained by the simulated cable coupling effect testing device and taking the abscissa as frequency and the ordinate as a voltage amplitude logarithm value;
and reflecting the obtained 4 frequency spectrum curves in a curve graph, wherein the left vertical axis is a current amplitude logarithm value, the right vertical axis is a voltage amplitude logarithm value, and the abscissa is frequency, so that the coupling interference effect level is reflected.
Preferably, the coaxial cable test structure consists of a current test cabin and a voltage test cabin;
the current test cabin respectively penetrates the simulation shielding cable and the measurement coaxial cable through an interface which is provided with a penetrating piece form outside, and a current probe connected with the measurement coaxial cable is connected to the simulation shielding cable in the cabin to carry out shielding layer induced current test;
the voltage test cabin is internally provided with an impedance matching circuit with continuously adjustable impedance, the simulation shielded cable is connected to the impedance matching circuit through a penetrating piece, and a core wire coupling voltage interface is reserved outside the voltage test cabin; the coaxial cable test structure is used for testing the shielding effectiveness under the laboratory condition, and the shielding effectiveness of the current test cabin and the voltage test cabin is better than 30dB in the set test frequency range.
Preferably, the system further comprises a test system calibration device prior to the analog cable coupling effect test device, and the test system calibration device further comprises a low-frequency calibration structure and a medium-frequency calibration structure;
the low-frequency verification structure comprises a low-frequency signal generator, an amplifier, a standard resistor, a receiver C, an oscilloscope and a current probe; the low-frequency signal generator is connected with the amplifier, and the output of the amplifier is connected with a standard resistor; connecting a current probe on a resistance loop single line, wherein the output of the current probe is connected to the receiver C; the oscilloscope is connected in parallel with two ends of the standard resistor; the signal generator applies a check signal in a low-frequency range, and 1 frequency point is selected at regular frequency intervals; measuring the current level by using an oscilloscope, and simultaneously confirming that the current waveform is a sine wave; confirming that the measured value of the receiver is within +/-3 dB of the measured value of the current of the oscilloscope;
the intermediate frequency checking structure comprises a current probe, a receiver D, a radio frequency signal generator, a central conductor and a coaxial load; the current probe is connected to the central conductor, and the output of the current probe is connected with the receiver D; one end of the central conductor is connected with a coaxial load, and the other end of the central conductor is connected with the radio frequency signal generator; the radio frequency signal generator applies a check signal in a test frequency range, and a certain number of frequency points are selected in each octave in a middle frequency range; the receiver D measures the current of the center conductor, confirming that the measurement is within 3dB of the amplitude of the verification signal applied by the signal generator.
Preferably, the system further comprises a cable coupling interference effect pre-testing device prior to the simulated cable coupling effect testing device and a simulated cable transfer impedance testing device prior to the external field cable coupling effect testing device;
the cable coupling interference effect pre-testing device comprises a receiver E, a receiver F, a signal generating structure, a transmitting loop, a coupling loop, a third cable interface box, a fourth cable interface box, a current probe and a standard resistor; the transmitting loop, the coupling loop, the third cable interface box and the fourth cable interface box are laid according to the laying condition of the simulation cable coupling effect testing device; the two ends of the transmitting loop are respectively connected with a standard resistor and the signal generating structure; the current probe connected with the receiver E is connected to the transmitting loop, the current probe connected with the receiver F is connected to the coupling loop in the third or fourth cable interface box, and the shielding sheath is mounted on the current probe connected with the receiver E; the signal generating structure applies a check signal to the transmitting loop in a set testing frequency range, test frequency points are selected at regular intervals in a low frequency band, and a plurality of test frequency points are selected in an intermediate frequency band according to each octave; controlling the signal to be in a fixed amplitude, keeping the current of the transmitting loop under each frequency unchanged, and confirming that the deviation of the measured values of the receiver E and the receiver F is within the range of +/-3 dB;
the transfer impedance test device of the analog cable carries out transfer impedance test on the cable with the same model or the same structural characteristics as the tested cable under the laboratory condition to obtain a transfer impedance curve graph in a set test frequency range, and the curve graph is used as the transfer impedance data.
The invention also comprises a cable coupling interference effect testing method, which comprises a simulation cable coupling effect test and comprises the following specific steps:
step 101, laying according to the requirement of the simulation cable coupling effect testing device; respectively connecting two ends of the simulation shielded cable into the first cable interface box and the second cable interface box, and adjusting matching resistors in the two cable interface boxes to enable the two cable interface boxes to be grounded well; at least 1 of the first cable interface box and the second cable interface box adopts the coaxial cable test structure; connecting a current probe in the coaxial cable test structure and the receiver A through a measuring coaxial cable, and connecting the core wire coupling voltage interface of the coaxial cable test structure and the receiver A through the measuring coaxial cable; the current probe is arranged in a current test cabin of the coaxial cable test structure and connected to the simulation shielded cable in parallel;
and 102, interfering the equipment at two ends of the cable to start and run on site and reaching a normal working state, setting the measurement receiver in test software according to the specified bandwidth and measurement time, scanning in the set test frequency range, and respectively testing the induced current of the shielding layer and the coupling voltage of the core wire.
Preferably, the method comprises the step of testing the coupling effect of the external field cable, and the specific steps comprise:
step 201, connecting a current probe and a receiver B through a measuring coaxial cable; connecting the data recording device to a receiver B; the equipment at two ends of the tested cable is in a shutdown state; installing a current probe on the tested cable and installing a shielding sheath;
step 202, starting other devices except the devices at the two ends of the tested cable to run and reach a normal working state, selecting and configuring a current probe coefficient in test software, setting a receiver B according to a specified bandwidth and measurement time, and scanning induction current data of a shielding layer in a set test frequency range;
step 203, forming a first shielding layer induced current spectrum curve by using shielding layer induced current data obtained by the external field cable coupling effect test and taking the abscissa as frequency and the ordinate as a current amplitude logarithm value; converting the induced current data of the shielding layer obtained by the outfield cable coupling effect test by transferring impedance data to obtain cable core coupling voltage data, and forming a first cable core coupling voltage spectrum curve by taking the abscissa as frequency and the ordinate as a voltage amplitude logarithm value;
step 204, using the abscissa as the frequency and the ordinate as the current amplitude logarithm value of the shielding layer induced current data obtained by the simulation cable coupling effect test to form a second shielding layer induced current frequency spectrum curve; forming a second cable core coupling voltage frequency spectrum curve by using the core coupling voltage data obtained by the simulation cable coupling effect test and taking the abscissa as frequency and the ordinate as a voltage amplitude logarithm value;
step 205, the obtained 4 spectrum curves are reflected in a graph, wherein the left vertical axis is a current amplitude log value, the right vertical axis is a voltage amplitude log value, and the abscissa is frequency.
Preferably, before step 101, the method includes cable coupling interference effect pre-test and test system verification:
the cable coupling interference effect pretest comprises:
301, laying a transmitting loop, a coupling loop, a third cable interface box and a fourth cable interface box according to the laying condition of the simulation cable coupling effect testing device; the two ends of the transmitting loop are respectively connected with a standard resistor and a signal generating structure; a current probe connected with a receiver E is connected to the transmitting loop, a current probe connected with a receiver F is connected to the coupling loop in the third or fourth cable interface box, and a shielding sheath is mounted on the current probe connected with the receiver E;
step 302, the signal generating structure applies a check signal to the transmitting loop in a set testing frequency range, test frequency points are selected at regular intervals in a low frequency band, and a certain number of test frequency points are selected in a middle frequency band according to each octave; controlling the signal to be in a fixed amplitude, keeping the current of the transmitting loop unchanged at each frequency, and confirming that the deviation of the measured values of the receiver E and the receiver F is within the range of +/-3 dB;
the test system calibration specifically comprises low-frequency band test system calibration and medium-frequency band test system calibration; and checking whether the error of the measurement result of the measurement receiver is within the acceptance range at each frequency point of the low-frequency band and the middle-frequency band respectively.
Preferably, before step 201, an analog cable transfer impedance test is included;
the test of the transfer impedance of the analog cable specifically comprises the following steps: and (3) carrying out transfer impedance test on the cable similar to the same type of the tested simulation cable or the structural characteristic of the cable according to a method specified by national standards under the laboratory condition to obtain a transfer impedance curve graph in a set test frequency range, and taking the curve graph as the transfer impedance data.
Has the advantages that:
1. the method can accurately obtain the induced current of the shielding layer of the cable and the coupling voltage of the core wire generated in the external field environment, thereby evaluating the electromagnetic coupling interference level of the external field electromagnetic environment on the cable and providing theoretical data support for the electromagnetic compatibility of the external field test. The method is used for testing under the condition that the state of the cable on site and the laying, installation and arrangement of the cable are not influenced, the testing efficiency is high, the method is easy to realize, the practicability is good, the method is also suitable for testing the cable coupling interference effect of other platforms, the method does not depend on the platform, and the applicability is wide.
2. According to the invention, by arranging the external field cable coupling effect testing device and the data recording device, the induced current of the shielding layer of the cable and the core wire coupling voltage generated in the external field environment can be further accurately obtained, so that the electromagnetic coupling interference level of the external field electromagnetic environment on the cable can be evaluated.
3. The invention can visually and clearly reflect the test result in one icon through data processing.
4. According to the invention, through the design of the coaxial cable test structure, the test for the induced current of the cable shielding layer and the core wire coupling voltage is more accurate; the shielding effectiveness of the coaxial cable test structure and each test cabin thereof is more than or equal to 30dB, and the test error is reduced by shielding the influence of an external electromagnetic field.
5. The invention realizes the calibration of the instrument needed by the system simply through the design of the test system calibration device and the low-frequency calibration structure and the medium-frequency calibration structure thereof, and provides further guarantee for the precision and error elimination of the system.
6. According to the invention, the accuracy of the cable coupling interference effect test reaches the range of +/-3 dB through the pretest, the shielding effectiveness of the shielding sheath of the current probe is more than or equal to 30dB, and the test result is more accurate by shielding the influence of an external electromagnetic field.
7. According to the invention, by preferably limiting the laying requirements and the probe positions, the precision and the feasibility of the test are improved, and meanwhile, the actual arrangement situation of the whole test can be better simulated, so that the test result has more practical significance.
Drawings
FIG. 1 is a schematic diagram of the 1 kHz-10 kHz test system in the present invention;
FIG. 2 is a schematic diagram of the calibration of the 10 kHz-10 MHz test system in the present invention;
FIG. 3 is a schematic view of a cable coupling effect interface box according to the present invention;
FIG. 4 is a schematic diagram of a 1 kHz-10 kHz cable coupling interference effect pretest in the present invention;
FIG. 5 is a schematic diagram of a pre-test of the coupling interference effect of a 10 kHz-10 MHz cable in the invention;
FIG. 6 is a schematic diagram of the coupling effect test of the outfield cable of the present invention;
FIG. 7 is a schematic diagram of a test of the coupling effect of a simulated cable according to the present invention.
Detailed Description
The invention is described in detail below by way of example with reference to the accompanying drawings.
The invention provides a cable coupling interference effect test system and a method thereof, and the core idea is as follows:
the system comprises a simulation cable coupling effect testing device; the simulation cable coupling effect testing device comprises a simulation shielded cable, a first cable interface box, a second cable interface box and a receiver A; the simulation cable coupling effect testing device is laid in a site interference cable within 10cm and simulates actual situation arrangement; simulating the effective coupling length between the shielding cable and the field interference cable to be more than 3m, and simulating the arrangement of an actual situation; the simulation shielded cable selects a cable with the same model or structural characteristics as the tested cable; at least 1 of the first cable interface box and the second cable interface box adopts a coaxial cable test structure; the coaxial cable test structure is used for measuring the induced current of the shielding layer of the analog shielding cable and the coupling voltage of the core wire; the receiver A is used for connecting a core wire coupling voltage interface led out from a voltage test cabin in the coaxial cable test structure and connecting a current probe in a current test cabin through a measuring coaxial cable so as to reflect the coupling interference effect level.
Therefore, the method can accurately obtain the induced current of the shielding layer of the cable and the coupling voltage of the core wire generated in the external field environment, thereby evaluating the electromagnetic coupling interference level of the external field electromagnetic environment on the cable and providing theoretical data support for the electromagnetic compatibility of the external field test. The method is used for testing under the condition that the state of the cable on site and the laying, installation and arrangement of the cable are not influenced, is high in testing efficiency, easy to realize, good in practicability, and wide in applicability, and is also suitable for testing the cable coupling interference effect of other platforms, and independent of the platforms.
The invention mainly comprises three parts of preparation work, a test process and data processing, and the invention is further explained in detail by an embodiment.
The preparation work required before the test mainly comprises the following steps: the method comprises the following steps of checking measuring instruments and meters, testing transfer impedance of an analog cable, trial-manufacturing a coaxial cable test structure, and pre-testing the coupling interference effect of a current probe shielding sheath and the cable, and specifically comprises the following steps:
1. the calibration of the measuring instrument is divided into 1 kHz-10 kHz calibration and 10 kHz-10 MHz calibration according to the frequency band, and the 1 kHz-10 kHz calibration comprises the following specific steps:
1. the connection of the low-frequency verification structure of the test system verification device is carried out according to fig. 1, which specifically comprises the following steps:
1.1, connecting the outputs of a low-frequency signal generator and an amplifier with a standard resistance load;
and 1.2, connecting a current probe to a single line of a resistance load loop, connecting the output of the probe to a measurement receiver, and connecting an oscilloscope to two ends of a resistor.
2. Applying a check signal in the range of 1 kHz-10 kHz by using a signal generator, and selecting 1 frequency point every 1kHz in the range of 1 kHz-10 kHz;
3. measuring the current level with an oscilloscope and a resistor, and simultaneously checking whether the current waveform is a sine wave;
4. the measurement receiver scans according to the normal data scanning mode, and confirms that the measured value is within +/-3 dB of the current measured value of the oscilloscope;
5. if the measured values deviate by more than + -3 dB, the error cause is found and corrected before testing.
The calibration of 10 kHz-10 MHz comprises the following specific steps:
1. the connection of the intermediate frequency verification structure of the test system verification device is performed according to fig. 2, which specifically comprises:
1.1, clamping a current probe on a central conductor of a checking device, wherein one end of a measuring coaxial cable is connected with the current probe, and the other end of the measuring coaxial cable is connected with a measuring receiver;
1.2, one end of the checking device is connected with a coaxial load of 50 omega, and the other end of the checking device is connected with a radio frequency signal generator;
2. the test instrument equipment is electrified and preheated to reach a stable working state;
3. applying a check signal in a test frequency range by using a signal generator, and selecting at least 5 frequency points in each octave in the range of 10 kHz-10 MHz;
4. measuring the current level of the central conductor of the checking device by using a measuring receiver, scanning by using the measuring receiver according to a normal data scanning mode, and confirming that the measured value is within +/-3 dB range of the amplitude of a checking signal applied by a signal generator;
5. if the measured values deviate by more than +/-3 dB, the error reason is found and corrected before testing.
Through the design of the test system calibration device and the low-frequency calibration structure and the medium-frequency calibration structure thereof, the calibration of the instruments required by the system is simply realized, and further guarantee is provided for the precision and error elimination of the system.
2. Transfer impedance testing of analog cables
And (3) carrying out transfer impedance test on the cable similar to the cable type or the cable structure characteristic of the simulated system under the laboratory condition by a third-party detection mechanism according to a method specified by the national standard, and obtaining a transfer impedance curve graph in the frequency band of 1 kHz-10 MHz as test preparation data.
3. Trial production of coaxial cable test structure of cable interface box
According to the characteristics and interface forms of tested cables, a coaxial cable test structure is designed and manufactured in a trial mode as shown in figure 3, the coaxial cable test structure mainly comprises a shielding layer induced current test cabin and a core wire coupling voltage test cabin, the shielding layer induced current test cabin can actually simulate the interface forms of the tested cables, a penetrating piece form interface is reserved outside the shielding layer induced current test cabin, the simulated cables can be directly penetrated, and a current probe can be connected to the cables in the shielding layer induced current test cabin for induced current test. The core wire coupling voltage test cabin is provided with a core wire coupling voltage test port, an impedance matching circuit with continuously adjustable impedance is arranged in the cabin, a cable can be connected into the impedance matching circuit of the core wire coupling voltage test cabin through a penetrating piece type interface, the impedance characteristics of a source end and a load end can be simulated as much as possible, or a voltage signal is adopted to simulate a severe environment according to a high-resistance mode, and a current signal simulates a severe environment according to a low-resistance mode.
In order to eliminate the influence of coupling interference factors of an interface box in the process of cable coupling interference effect test and reduce the influence of space magnetic field factors measured by a current probe, shielding effectiveness test is carried out under laboratory conditions according to a method specified by national standard, shielding effectiveness within a frequency band of 1 kHz-10 MHz is obtained, and the shielding effectiveness is confirmed to be superior to 30dB.
Through trial manufacture of a coaxial cable test structure and design of the coaxial cable test structure, the test for induced current and core wire coupling voltage of a cable shielding layer is more accurate; the shielding effectiveness of the coaxial cable test structure and each test cabin thereof is more than or equal to 30dB, and the test error is reduced by shielding the influence of an external electromagnetic field.
4. Current probe shielding sheath
In order to reduce the influence of space magnetic field factors on the current probe in the cable coupling interference effect test process, a current probe shielding sheath is prepared before the test, the shielding sheath is made of a metal shielding material with shielding effectiveness not less than 30dB in a frequency range of 1 kHz-10 MHz, and the installation size of the metal shielding material can be matched with that of the current probe for the test. The current probe shielding sheath enables a test result to be more accurate by shielding the influence of an external electromagnetic field.
5. Cable coupling interference effect pre-test
In order to ensure the accuracy of a field test, a cable coupling interference effect pre-testing device can be arranged on a cable coupling interference test fixed rack in a laboratory to perform pre-testing, and the pre-testing is to perform cable coupling interference effect testing under standard interference injection according to a sensitivity item testing method and configuration of CS101, CS114 and the like in GJB 151B-2013. The test schematic diagram is shown in fig. 4 and 5, and the steps are as follows:
1. assembling a pre-testing device for coupling interference effect of a connecting cable, performing 1 kHz-10 kHz pre-testing according to the connection of a testing instrument and a meter in a figure 4, and performing 10 kHz-10 MHz pre-testing according to a figure 5;
2. connecting a current probe A on a transmitting loop, connecting a current probe B in a cable interface box and connecting the current probe B on a coupling loop, wherein a current probe shielding sheath is arranged on the current probe A;
3. applying a check signal in a range of 1 kHz-10 MHz by using a signal generator, selecting 1 frequency point every 1kHz by using a low-frequency signal generator in the range of 1 kHz-10 kHz, and selecting at least 5 frequency points every octave by using a radio-frequency generator in the range of 10 kHz-10 MHz;
4. the signal generator is regulated at a fixed amplitude, and when one frequency is generated, the current of a transmitting loop needs to be kept unchanged as much as possible, and the readings of receivers connected with the current probes A and B are recorded respectively.
5. Under the condition of keeping the current of the transmitting loop consistent, repeating the test for three times or replacing different instruments including a receiver or a frequency spectrograph for testing, and comparing whether the reading deviation of the same frequency point at the same position of the receiver for three times is within the range of +/-3 dB;
6. if the deviation of the repeated measured value exceeds +/-3 dB, the error reason needs to be found and corrected.
According to the invention, the accuracy of the cable coupling interference effect test reaches the range of +/-3 dB through the pretest, so that the test result is more accurate.
The test process mainly comprises an external field cable coupling effect test and a simulation cable coupling effect test, and specifically comprises the following steps:
1. and (3) testing the coupling effect of the external field cable, namely testing induced current of the shielding layer, and then converting transfer impedance to obtain core wire coupling voltage. The test was performed according to the following procedure:
1. connecting and assembling an external field cable coupling effect testing device and a data recording device, wherein one end of the measuring coaxial cable is connected with a current probe, and the other end of the measuring coaxial cable is connected with a measuring receiver; the data logging device is connected to the measurement receiver, as shown in fig. 6.
2. The equipment at the two ends of the tested cable is in a shutdown state;
3. installing a shielding sheath for the current probe and connecting the shielding sheath on the coupling cable to be tested, preferably arranging the shielding sheath at a position 5cm away from a tested equipment end connector of the cable to be tested, and selecting equal distances of 10cm, 50cm and 1m according to the field arrangement condition, wherein the maximum distance is less than or equal to 1m;
through preferably restricting probe position, not only promote the precision and the feasibility of test, also let whole test can better simulate the actual situation of arranging simultaneously, make the test result more have realistic meaning.
4. Starting up other equipment except equipment at two ends of a tested cable to run and reach a normal working state, selecting and configuring a current probe coefficient in test software, setting a measurement receiver according to bandwidth and measurement time specified in GJB151B-2013, scanning within a test frequency range of 1 kHz-10 MHz, storing induced current frequency spectrum data of a shielding layer at the moment, and recording the serial number of a data file and the working state of other equipment at the moment;
2. and (3) testing the coupling effect of the analog cable, namely arranging and installing an analog cable coupling measuring device consisting of the analog shielding cable and the cable interface box near the on-site interference cable, and obtaining the induced current of the shielding layer and the induced voltage of the core wire through direct testing. The test was performed according to the following procedure:
1. as shown in fig. 7, the connecting and assembling device for testing the coupling effect of the analog cable specifically comprises the following steps:
1.1, adjusting the matching resistance of a coaxial cable test structure according to the source/load characteristics of a tested cable, laying a simulation shielding cable within 10cm from a coupling cable to be tested of a concerned field interference source, and simulating the distance arrangement of a real boat, wherein the coupling length of the tested simulation cable simulates the real boat to be at least 3m;
by preferably limiting the laying requirements, the precision and the feasibility of the test are improved, and meanwhile, the actual arrangement situation can be better simulated through the whole test, so that the test result has more practical significance.
1.2, the both ends of simulation shielded cable can all select for use coaxial cable test structure, also can one end select for use coaxial cable test structure and one end inserts a suitable impedance, select for use two cable interface boxes to do respectively in this device usually: a first cable interface box and a second cable interface box, both of which are well grounded; wherein the first cable interface box adopts a coaxial cable test structure;
1.3, connecting one end of a measuring coaxial cable with a current probe and the other end with a measuring receiver, and connecting a measuring coaxial cable for a core wire coupling voltage interface on a coaxial cable test structure into the measuring receiver;
1.4, connecting a data recording device with a measurement receiver;
2. installing a current probe in a shielding layer induced current test cabin in a coaxial cable test structure and connecting the current probe on the simulated shielding cable in parallel;
3. the method comprises the steps of interfering equipment at two ends of a cable to start and run and achieving a normal working state, setting a measurement receiver in test software according to the bandwidth and the measurement time specified in GJB151B-2013, scanning within the test frequency range of 1 kHz-10 MHz, respectively testing the induced current of a shielding layer and the voltage of a core wire, storing the frequency spectrum data of the induced current of the shielding layer and the frequency spectrum data of the voltage of the core wire at the moment, and recording the serial number of a data file and the working state of other equipment at the moment.
The method needs to perform data processing after the test is finished, and specifically comprises the following steps:
1. outfield cable coupling effect test data processing
1.1, forming a shielding layer induced current frequency spectrum curve chart by using the shielding layer induced current data obtained by the test according to the mode of a logarithmic coordinate system with the abscissa as frequency (Hz) and the ordinate as amplitude (dB mu A);
1.2, converting the transfer impedance data measured by the third-party detection mechanism to obtain cable core coupling voltage data, and forming a cable core coupling voltage spectrum curve chart according to the frequency (Hz) on the abscissa and the amplitude (dB mu V) on the ordinate in a logarithmic coordinate system mode.
2. Analog cable coupling effect test data processing
2.1, forming a shielding layer induced current frequency spectrum curve chart by testing the obtained shielding layer induced current data according to a mode that the abscissa is frequency (Hz) and the ordinate is amplitude (dB mu A) and a logarithmic coordinate system is adopted;
2.2, forming a voltage spectrum curve chart of the cable core wire by using the core wire coupling voltage data obtained by the test according to the mode that the abscissa is frequency (Hz) and the ordinate is amplitude (dB mu V) and a logarithmic coordinate system;
3. the data after 1.2 and 2.2 processing are reflected in a graph with current amplitude on the left vertical axis, voltage amplitude on the right vertical axis, frequency (Hz) on the abscissa and logarithmic coordinate system.
By applying the invention, the induced current of the shielding layer and the induced voltage of the core wire can be tested. The test result can be intuitively and clearly reflected in one icon through data processing.
In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A cable coupling interference effect test system is characterized by comprising a simulation cable coupling effect test device; the simulation cable coupling effect testing device comprises a simulation shielded cable, a first cable interface box, a second cable interface box and a receiver A;
the simulation cable coupling effect testing device is laid within 10cm of the site interference cable and simulates actual situation arrangement; the effective coupling length between the simulated shielded cable and the field interference cable is larger than 3m, and the actual situation arrangement is simulated; the simulation shielded cable is a cable with the same model or structural characteristics as the tested cable;
at least 1 of the first cable interface box and the second cable interface box adopts a coaxial cable test structure; the coaxial cable test structure is used for measuring the induced current of a shielding layer and the coupling voltage of a core wire of the analog shielding cable;
the receiver A is used for connecting a core wire coupling voltage interface led out from a voltage test cabin in the coaxial cable test structure and connecting a current probe in the current test cabin through a measuring coaxial cable so as to reflect the coupling interference effect level.
2. The cable coupling interference effect testing system of claim 1, further comprising an external field cable coupling effect testing device;
the external field cable coupling effect testing device comprises a current probe and a receiver B; the receiver B is connected with a current probe through a measuring coaxial cable, the current probe is arranged on the tested cable, and a shielding sheath is arranged; the distance between the current probe and the equipment end is less than 1m; the shielding sheath is made of a metal shielding material with shielding effectiveness not less than 30dB in a set testing frequency range, and a current probe with a size adapted to the shielding sheath is installed; and the receiver B measures the induction current data of the shielding layer of the tested cable, and converts the obtained induction current data of the shielding layer by transferring impedance data to obtain the coupling voltage data of the cable core wire and reflect the coupling interference effect level.
3. The cable coupling interference effect testing system of claim 2, wherein the system further comprises a data logging device;
the data recording device receives data input of the receivers A and B, and the induced current data of the shielding layer of the tested cable obtained by the external field cable coupling effect testing device is subjected to frequency treatment by taking the abscissa as the frequency and the ordinate as the current amplitude logarithm value to form a first shielding layer induced current frequency spectrum curve; converting the cable core wire coupling voltage data of the tested cable obtained by the outfield cable coupling effect testing device by taking an abscissa as frequency and an ordinate as a voltage amplitude logarithm value to form a first cable core wire coupling voltage frequency spectrum curve;
forming a second shielding layer induced current frequency spectrum curve by using the shielding layer induced current data of the simulated shielding cable obtained by the simulated cable coupling effect testing device and taking the abscissa as the frequency and the ordinate as the current amplitude logarithm value; forming a second cable core wire coupling voltage frequency spectrum curve by using the core wire coupling voltage data of the simulated shielded cable obtained by the simulated cable coupling effect testing device and taking the abscissa as frequency and the ordinate as a voltage amplitude logarithm value;
and reflecting the obtained 4 frequency spectrum curves in a curve graph, wherein the left vertical axis is a current amplitude logarithm value, the right vertical axis is a voltage amplitude logarithm value, and the abscissa is frequency, so that the coupling interference effect level is reflected.
4. The cable coupling interference effect testing system of claim 1 wherein the coaxial cable test structure is comprised of a current test compartment and a voltage test compartment;
the current test cabin respectively penetrates the simulation shielding cable and the measurement coaxial cable through an interface which is reserved outside in a penetrating piece mode, and a current probe connected with the measurement coaxial cable is connected to the simulation shielding cable in the cabin to carry out shielding layer induced current test;
the voltage test cabin is internally provided with an impedance matching circuit with continuously adjustable impedance, the simulation shielded cable is connected into the impedance matching circuit through a penetrating piece, and a core wire coupling voltage interface is reserved outside the voltage test cabin; the coaxial cable test structure is used for testing the shielding effectiveness under the laboratory condition, and the shielding effectiveness of the current test cabin and the voltage test cabin is better than 30dB in a set test frequency range.
5. The cable coupling interference effect testing system of claim 1 or 2 further comprising a testing system verification device prior to said simulated cable coupling effect testing device, said testing system verification device further comprising a low frequency verification structure and a mid frequency verification structure;
the low-frequency verification structure comprises a low-frequency signal generator, an amplifier, a standard resistor, a receiver C, an oscilloscope and a current probe; the low-frequency signal generator is connected with the amplifier, and the output of the amplifier is connected with a standard resistor; connecting a current probe to the resistance loop single line, and connecting the output of the current probe to the receiver C; the oscilloscope is connected in parallel with two ends of the standard resistor; the signal generator applies a check signal in a low-frequency range, and 1 frequency point is selected at regular frequency intervals; measuring the current level by using an oscilloscope, and simultaneously confirming that the current waveform is a sine wave; confirming that the measured value of the receiver is within +/-3 dB of the measured value of the current of the oscilloscope;
the intermediate frequency checking structure comprises a current probe, a receiver D, a radio frequency signal generator, a central conductor and a coaxial load; the current probe is connected to the central conductor, and the output of the current probe is connected with the receiver D; one end of the central conductor is connected with a coaxial load, and the other end of the central conductor is connected with the radio frequency signal generator; the radio frequency signal generator applies a check signal in a test frequency range, and a certain number of frequency points are selected in each octave in a middle frequency range; the receiver D measures the current of the center conductor, confirming that the measurement is within 3dB of the amplitude of the verification signal applied by the signal generator.
6. The cable coupling interference effect testing system of claim 2 further comprising a cable coupling interference effect pretesting means preceding said simulated cable coupling effect testing means and a simulated cable transfer impedance testing means preceding said external field cable coupling effect testing means;
the cable coupling interference effect pre-testing device comprises a receiver E, a receiver F, a signal generating structure, a transmitting loop, a coupling loop, a third cable interface box, a fourth cable interface box, a current probe and a standard resistor; the transmitting loop, the coupling loop, the third cable interface box and the fourth cable interface box are laid according to the laying condition of the simulation cable coupling effect testing device; the two ends of the transmitting loop are respectively connected with a standard resistor and the signal generating structure; the current probe connected with the receiver E is connected to the transmitting loop, the current probe connected with the receiver F is connected to the coupling loop in the third or fourth cable interface box, and the shielding sheath is mounted on the current probe connected with the receiver E; the signal generating structure applies a check signal to the transmitting loop in a set testing frequency range, test frequency points are selected at regular intervals in a low frequency band, and a plurality of test frequency points are selected in an intermediate frequency band according to each octave; controlling the signal to be in a fixed amplitude, keeping the current of the transmitting loop unchanged at each frequency, and confirming that the deviation of the measured values of the receiver E and the receiver F is within the range of +/-3 dB;
the simulated cable transfer impedance testing device performs transfer impedance testing on cables with the same model or the same structural characteristics as the tested cable under the laboratory condition to obtain a transfer impedance curve diagram in a set testing frequency range, and the curve diagram is used as the transfer impedance data.
7. A cable coupling interference effect test method based on any one of the test systems of claims 1-6, which is characterized by comprising a simulation cable coupling effect test, and the specific steps comprise:
step 101, laying according to the requirement of the simulation cable coupling effect testing device; respectively connecting two ends of the simulation shielded cable into the first cable interface box and the second cable interface box, and adjusting matching resistors in the two cable interface boxes to enable the two cable interface boxes to be grounded well; at least 1 of the first cable interface box and the second cable interface box adopts the coaxial cable test structure; connecting a current probe in the coaxial cable test structure and the receiver A through a measuring coaxial cable, and connecting the core wire coupling voltage interface of the coaxial cable test structure and the receiver A through the measuring coaxial cable; the current probe is arranged in a current test cabin of the coaxial cable test structure and connected to the simulation shielded cable in parallel;
and 102, the equipment at two ends of the field interference cable is started to run and reaches a normal working state, the measurement receiver is set according to the specified bandwidth and the measurement time in the test software, scanning is carried out in the set test frequency range, and the induced current of the shielding layer and the coupling voltage of the core wire are respectively tested.
8. The method for testing the cable coupling interference effect according to claim 7, comprising an external field cable coupling effect test, the specific steps comprising:
step 201, connecting a current probe and a receiver B through a measuring coaxial cable; connecting the data recording device to receiver B; the equipment at two ends of the tested cable is in a shutdown state; installing a current probe on the tested cable and installing a shielding sheath;
step 202, starting other devices except the devices at the two ends of the tested cable to run and reach a normal working state, selecting and configuring a current probe coefficient in test software, setting a receiver B according to a specified bandwidth and measurement time, and scanning induction current data of a shielding layer in a set test frequency range;
step 203, forming a first shielding layer induced current frequency spectrum curve by using shielding layer induced current data obtained by the external field cable coupling effect test and taking an abscissa as frequency and an ordinate as a current amplitude logarithm value; converting the induced current data of the shielding layer obtained by the outfield cable coupling effect test by transferring impedance data to obtain cable core coupling voltage data, and forming a first cable core coupling voltage spectrum curve by taking the abscissa as frequency and the ordinate as a voltage amplitude logarithm value;
step 204, forming a second shielding layer induced current frequency spectrum curve by using shielding layer induced current data obtained by the simulation cable coupling effect test and taking the abscissa as frequency and the ordinate as a current amplitude logarithm value; forming a second cable core coupling voltage frequency spectrum curve by using the core coupling voltage data obtained by the simulation cable coupling effect test and taking the abscissa as frequency and the ordinate as a voltage amplitude logarithm value;
step 205, the obtained 4 spectrum curves are reflected in a graph, wherein the left vertical axis is a current amplitude log value, the right vertical axis is a voltage amplitude log value, and the abscissa is frequency.
9. The method of claim 7 or 8, comprising, before step 101, a cable coupling interference effect pretest and a test system verification of:
the cable coupling interference effect pre-test comprises:
step 301, laying a transmitting loop, a coupling loop, a third cable interface box and a fourth cable interface box according to the laying condition of the simulation cable coupling effect testing device; the two ends of the transmitting loop are respectively connected with the standard resistor and the signal generating structure; a current probe connected with a receiver E is connected to the transmitting loop, a current probe connected with a receiver F is connected to the coupling loop in the third or fourth cable interface box, and a shielding sheath is mounted on the current probe connected with the receiver E;
step 302, the signal generating structure applies a check signal to the transmitting loop within a set testing frequency range, selects testing frequency points at regular intervals within a low frequency band, and selects a certain number of testing frequency points per octave within a medium frequency band; controlling the signal to be in a fixed amplitude, keeping the current of the transmitting loop unchanged at each frequency, and confirming that the deviation of the measured values of the receiver E and the receiver F is within the range of +/-3 dB;
the test system calibration specifically comprises low-frequency band test system calibration and medium-frequency band test system calibration; and checking whether the error of the measuring result of the measuring receiver is within the acceptance range at each frequency point of the low-frequency band and the middle-frequency band respectively.
10. The method for testing the cable coupling interference effect according to claim 8, wherein before step 201, the method comprises simulating a cable transfer impedance test;
the test of the transfer impedance of the analog cable specifically comprises the following steps: and (3) carrying out transfer impedance test on the cable similar to the same type of the tested simulation cable or the structural characteristic of the cable according to a method specified by national standards under the laboratory condition to obtain a transfer impedance curve graph in a set test frequency range, and taking the curve graph as the transfer impedance data.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211333718.3A CN115792427A (en) | 2022-10-28 | 2022-10-28 | Cable coupling interference effect test system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211333718.3A CN115792427A (en) | 2022-10-28 | 2022-10-28 | Cable coupling interference effect test system and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115792427A true CN115792427A (en) | 2023-03-14 |
Family
ID=85434203
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211333718.3A Pending CN115792427A (en) | 2022-10-28 | 2022-10-28 | Cable coupling interference effect test system and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115792427A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116660671A (en) * | 2023-07-28 | 2023-08-29 | 北京芯可鉴科技有限公司 | Broadband transient interference measurement influence factor verification method and device |
-
2022
- 2022-10-28 CN CN202211333718.3A patent/CN115792427A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116660671A (en) * | 2023-07-28 | 2023-08-29 | 北京芯可鉴科技有限公司 | Broadband transient interference measurement influence factor verification method and device |
| CN116660671B (en) * | 2023-07-28 | 2023-09-22 | 北京芯可鉴科技有限公司 | Broadband transient interference measurement influence factor verification method and device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Shafiq et al. | Parameters identification and modeling of high-frequency current transducer for partial discharge measurements | |
| CN109828162B (en) | Electromagnetic interference prediction method and system | |
| CN109116182B (en) | Device and method for measuring shielding effectiveness of shielding case of communication cable connector | |
| CN109655671B (en) | High-intensity radiation field effect test system and test method for low-level sweep current | |
| KR101939758B1 (en) | Method for measuring performance of antenna | |
| CN103336192A (en) | A low-level scanning current testing system for an aircraft whole body | |
| CN115792427A (en) | Cable coupling interference effect test system and method | |
| CN111239520B (en) | Method for evaluating high-power microwave protection efficiency of protection circuit module | |
| CN111426924A (en) | High-frequency partial discharge signal mode recognition function verification method and system | |
| CN110412371A (en) | Multi-coaxial cable assembly shield effectiveness detection method based on probe method | |
| US3952245A (en) | Calibrated quadraxial system for measuring shielding transfer impedance | |
| CN107561368A (en) | A kind of measuring system and measuring method of large scale electrical power unit wideband impedance operator | |
| CN208334615U (en) | A kind of calibration equipment of Bulk current injection pilot system | |
| CN110554247A (en) | crosstalk simulation modeling method and simulation model of non-parallel cable | |
| US10635778B2 (en) | Method for computer simulation and method for generating a transmission line model | |
| CN212749063U (en) | Instrument interface device | |
| Li et al. | An experimental analysis of the effects of wiring harness during bulk current injection (BCI) test | |
| Karnas et al. | Calibration of electric field antennae operating in the ELF-MF frequency range at the lightning research station in Rzeszow | |
| Cakir et al. | Loop-antenna calibration | |
| CN207232365U (en) | A kind of inspection circuit of partial discharge of transformer high frequency measuring instrument detection frequency band | |
| CN114629569A (en) | Testability test system and test method for wireless transceiving communication equipment | |
| CN112083237A (en) | Wide-frequency characteristic time domain measurement method and system for large-scale electrical equipment | |
| Burghart et al. | Evaluating the RF-emissions of automotive cable harness | |
| Cori et al. | Investigation of radiated susceptibility during EFT tests | |
| CN217717906U (en) | Static dynamic potential testing device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |