Field calibration system and method for high-frequency current sensor

Abstract

The invention provides a high-frequency current sensor field calibration system and method, and relates to the technical field of power supply systems. The verification system comprises a verification device and a high-frequency calibration current sensor. The verification device outputs multiple groups of pulse excitation signals with different amplitudes to the high-frequency calibration current sensor, collects a verification electric signal returned by the high-frequency calibration current sensor, and obtains a to-be-detected electric signal generated by the to-be-detected high-frequency current sensor collected and obtained by the high-frequency monitoring device; the verification device calculates a reference electric signal of the to-be-tested high-frequency current sensor according to the pulse excitation signal and the verification electric signal; and the verification device performs fitting comparison on the reference electric signal and the to-be-detected electric signal, and outputs a verification result of the to-be-detected high-frequency current sensor. According to the invention, the high-frequency current sensor is directly verified on the operation site of the transformer without power-off disassembly of equipment, so that the timeliness and flexibility of verification of the high-frequency current sensor are improved.

Description

Technical Field

[0001] This invention relates to the field of power supply system technology, and in particular to a high-frequency current sensor field calibration system and method. Background Technology

[0002] A high-frequency current sensor is a non-contact electromagnetic induction device used to detect high-frequency current signals, primarily for partial discharge monitoring and condition assessment of power equipment. The proper functioning of a high-frequency current sensor is crucial for the condition monitoring and assessment of transformers.

[0003] Currently, to ensure the reliability of power supply systems, on-site calibration of high-frequency current sensors is necessary. On one hand, on-site calibration requires numerous devices such as signal generators, high-frequency current sensor testing fixtures, and industrial control computers. On the other hand, on-site high-frequency current sensors are mostly fixed to the iron core and clamp grounding wires, making disassembly and assembly difficult. Furthermore, calibration is impossible while the transformer, high-frequency current sensor, and power equipment condition monitoring devices are running. In some large substations, transformer outage maintenance often needs to be planned and coordinated months in advance. Sending high-frequency current sensors to a laboratory for calibration might miss the optimal calibration window, increasing the risk of equipment operating with faults.

[0004] In summary, existing high-frequency current sensor field calibration requires disassembling and reassembling the sensor, resulting in poor timeliness and flexibility in field calibration. Summary of the Invention

[0005] This invention provides a field calibration system and method for high-frequency current sensors to address the issues of poor timeliness and flexibility in field calibration of high-frequency current sensors.

[0006] In a first aspect, embodiments of the present invention provide a field calibration system for a high-frequency current sensor. The system includes a calibration device and a high-frequency calibration current sensor. The calibration device is connected to the high-frequency calibration current sensor via a cable. The high-frequency calibration current sensor is installed at the grounding connection bar where the high-frequency current sensor under test is located. The high-frequency current sensor under test is connected to a high-frequency monitoring device via a cable. The calibration device is used to output multiple sets of pulse excitation signals with different amplitudes to the high-frequency calibration current sensor, and to collect the calibration electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor, as well as to acquire the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency current sensor under test, which is collected by the high-frequency monitoring device. The test electrical signal is generated based on the electromagnetic effect between the high-frequency current sensor under test and the grounding connection bar. The calibration device is also used to calculate the reference electrical signal of the high-frequency current sensor under test corresponding to each set of pulse excitation signals based on each set of pulse excitation signals and the calibration electrical signal corresponding to each set of pulse excitation signals. The calibration device is also used to fit and compare the reference electrical signals corresponding to multiple sets of pulse excitation signals with the electrical signals to be tested, and output the calibration results of the high-frequency current sensor under test.

[0007] In one possible implementation, the verification device is specifically used for: Based on each set of pulse excitation signals and the corresponding verification electrical signal, calculate the loss correction coefficient of the grounding connection bar under each set of pulse excitation signals and the magnetic flux generated by the magnetic field of the grounding connection bar. Based on the calibration coefficient of the high-frequency current sensor under test, the loss correction coefficient of the grounding connection bar under each set of pulse excitation signals, and the magnetic flux generated by the magnetic field of the grounding connection bar, the reference electrical signal of the high-frequency current sensor under test under each set of pulse excitation signals is calculated.

[0008] In one possible implementation, the reference electrical signal of the high-frequency current sensor under test is calculated based on the calibration coefficient of the high-frequency current sensor under test, the loss correction coefficient of the grounding busbar under each set of pulse excitation signals, and the magnetic flux generated by the magnetic field of the grounding busbar. This includes: The reference electrical signal of the high-frequency current sensor under test is calculated using the following formula. :

[0009] in, The calibration coefficient is the high-frequency current sensor under test. This is the loss correction factor for the grounding connection busbar. The magnetic flux generated by the grounding connection of the magnetic field. The number of coil turns of the high-frequency current sensor under test. The impedance of the high-frequency current sensor under test is given.

[0010] In one possible implementation, the calibration device is used to fit and compare the reference electrical signals corresponding to multiple sets of pulse excitation signals with the electrical signals to be tested, and output the calibration result of the high-frequency current sensor under test. Specifically, it is used for: Based on the reference electrical signals corresponding to multiple sets of pulse excitation signals, a reference curve is plotted using a curve fitting algorithm. Based on the electrical signals to be tested corresponding to multiple sets of pulse excitation signals, the measured curve is obtained through a curve fitting algorithm. Calculate the deviation between the reference curve and the measured curve, and determine whether the deviation is greater than the preset verification threshold. If the deviation is greater than the preset verification threshold, the performance of the high-frequency current sensor under test is determined to be abnormal; otherwise, the performance of the high-frequency current sensor under test is determined to be normal. Output the calibration results of the high-frequency current sensor under test, which include the performance judgment results of the high-frequency current sensor under test.

[0011] In one possible implementation, the high-frequency calibration current sensor includes a magnetic core, and a calibration coil and a verification coil wound on the magnetic core. The calibration signal is generated by the calibration coil in response to the combined magnetic field around it; the combined magnetic field includes a first magnetic field generated by the calibration coil in response to the pulse excitation signal in the magnetic core, and a second magnetic field generated by the grounding connection bar in response to the first magnetic field; The electrical signal to be tested is generated by the high-frequency current sensor under test in response to the second magnetic field.

[0012] In one possible implementation, the frequency of the pulse excitation signal is adjustable from 50 Hz to 10 kHz, the amplitude of the pulse excitation signal is adjustable from 0.3 V to 200 V, and the rise time of the pulse excitation signal is less than 10 ns.

[0013] Secondly, embodiments of the present invention provide a field verification method for a high-frequency current sensor, the method being applied to a verification system as described in the first aspect or any possible implementation thereof, the method comprising: Multiple sets of pulse excitation signals with different amplitudes are output to the high-frequency calibration current sensor, and the verification electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor is collected, as well as the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency current sensor under test is acquired by the high-frequency monitoring device. The test electrical signal is generated based on the electromagnetic effect between the high-frequency current sensor under test and the grounding connection bar. Based on each set of pulse excitation signals and the corresponding verification electrical signal, calculate the reference electrical signal of the high-frequency current sensor under test corresponding to each set of pulse excitation signals. The reference electrical signals corresponding to multiple sets of pulse excitation signals are fitted and compared with the electrical signals to be tested, and the verification results of the high-frequency current sensor under test are output.

[0014] In one possible implementation, based on each set of pulse excitation signals and the corresponding calibration electrical signal, a reference electrical signal for the high-frequency current sensor under test corresponding to each set of pulse excitation signals is calculated, specifically including: Based on each set of pulse excitation signals and the corresponding verification electrical signals, calculate the core loss correction coefficient, the grounding connection bar loss correction coefficient, and the magnetic flux generated by the grounding connection bar magnetic field of the high-frequency calibration current sensor under each set of pulse excitation signals. The calibration coefficient of the high-frequency current sensor under test is calculated based on the electrical signal to be tested corresponding to each set of pulse excitation signals, the core loss correction coefficient of the high-frequency calibration current sensor under each set of pulse excitation signals, the loss correction coefficient of the grounding connection bar, and the magnetic flux generated by the magnetic field of the grounding connection bar. Based on the calibration coefficient of the high-frequency current sensor under test under each set of pulse excitation signals, the reference electrical signal of the high-frequency current sensor under test under each set of pulse excitation signals is calculated.

[0015] In one possible implementation, based on the calibration coefficient of the high-frequency current sensor under test under each set of pulse excitation signals, a reference electrical signal of the high-frequency current sensor under test under each set of pulse excitation signals is calculated, including: The reference electrical signal of the high-frequency current sensor under test is calculated using the following formula. :

[0016] in, The calibration coefficient is the high-frequency current sensor under test. This is the loss correction factor for the grounding connection busbar. The magnetic flux generated by the grounding connection of the magnetic field. The number of coil turns of the high-frequency current sensor under test. The impedance of the high-frequency current sensor under test is given.

[0017] In one possible implementation, the reference electrical signals corresponding to multiple sets of pulse excitation signals are fitted and compared with the electrical signals to be tested, and the verification result of the high-frequency current sensor under test is output, specifically including: Based on the reference electrical signals corresponding to multiple sets of pulse excitation signals, a reference curve is plotted using a curve fitting algorithm. Based on the electrical signals to be tested corresponding to multiple sets of pulse excitation signals, the measured curve is obtained through a curve fitting algorithm. Calculate the deviation between the reference curve and the measured curve, and determine whether the deviation is greater than the preset verification threshold. If the deviation is greater than the preset verification threshold, the performance of the high-frequency current sensor under test is determined to be abnormal; otherwise, the performance of the high-frequency current sensor under test is determined to be normal. Output the calibration results of the high-frequency current sensor under test, which include the performance judgment results of the high-frequency current sensor under test.

[0018] In this embodiment of the invention, the high-frequency calibration current sensor is installed at the grounding connection bar where the high-frequency current sensor under test is located. The calibration device outputs multiple sets of pulse excitation signals of different amplitudes to the high-frequency calibration current sensor, and acquires the calibration electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor, as well as the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency monitoring device. The test electrical signal is generated based on the electromagnetic effect between the high-frequency current sensor under test and the grounding connection bar. The calibration device calculates the reference electrical signal of the high-frequency current sensor under test corresponding to each set of pulse excitation signals based on each set of pulse excitation signals and the corresponding calibration electrical signal. The calibration device fits and compares the reference electrical signals corresponding to multiple sets of pulse excitation signals with the test electrical signals, and outputs the calibration result of the high-frequency current sensor under test.

[0019] Therefore, this invention allows for the direct calibration of high-frequency current sensors at the transformer operating site without power outages or equipment disassembly, and without waiting for power outage maintenance windows, when the transformer is in normal operation. This effectively solves the problem of power outage time limitations in existing methods, greatly reduces the impact of high-frequency current sensor calibration on the normal operation of the power system, improves the timeliness and flexibility of calibration, and enhances the reliability of the power system. Attached Figure Description

[0020] Figure 1 This is one of the structural schematic diagrams of the high-frequency current sensor field calibration system provided in this embodiment of the invention; Figure 2 This is the second schematic diagram of the structure of the high-frequency current sensor field verification system provided in this embodiment of the invention; Figure 3 This is a flowchart illustrating the implementation of the on-site verification method for high-frequency current sensors provided in this embodiment of the invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0023] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities and do not necessarily imply a specific order or sequence, unless otherwise indicated. It should be understood that such terms can be used interchangeably where appropriate, for example, in situations where implementation can proceed in an order other than those given in the embodiments illustrated or described in this application.

[0024] Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover but not exclude inclusion. For example, a product or device that includes a series of components is not necessarily limited to those explicitly listed, but may include other components not explicitly listed or inherent to such product or device. As used in this application, the term "module" means any known or subsequently developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software code capable of performing the functions associated with that element.

[0025] A high-frequency current sensor is a non-contact electromagnetic induction device used to detect high-frequency current signals. It is mainly used for partial discharge monitoring and condition assessment of power equipment.

[0026] Currently, to ensure the reliability of power supply systems, on-site calibration of high-frequency current sensors is necessary. On one hand, on-site calibration requires numerous devices such as signal generators, high-frequency current sensor testing fixtures, and industrial control computers. On the other hand, on-site high-frequency current sensors are mostly fixed to the iron core and clamp grounding wires, making disassembly and assembly difficult. Furthermore, calibration is impossible while the transformer, high-frequency current sensor, and power equipment condition monitoring devices are running. In some large substations, transformer outage maintenance often needs to be planned and coordinated months in advance. Sending high-frequency current sensors to a laboratory for calibration might miss the optimal calibration window, increasing the risk of equipment operating with faults.

[0027] In summary, existing high-frequency current sensor field calibration requires disassembling and reassembling the sensor, resulting in poor timeliness and flexibility in field calibration.

[0028] Based on the aforementioned technical problems, the technical concept of this invention is as follows: A high-frequency calibration current sensor is installed on the grounding connection bar where the high-frequency current sensor under test is located. The calibration device outputs multiple sets of pulse excitation signals of different amplitudes to the high-frequency calibration current sensor. Utilizing the electromagnetic effect of the high-frequency current sensor under test, the high-frequency calibration current sensor, and the grounding connection bar, a magnetic field is generated around the high-frequency calibration current sensor and the high-frequency current sensor under test in response to the pulse excitation signals. The high-frequency calibration current sensor and the high-frequency current sensor under test respectively respond to the magnetic field around them, generating a calibration electrical signal and a test electrical signal. The calibration device acquires the calibration electrical signal and the test electrical signal, and generates the on-site calibration result of the high-frequency current sensor based on the pulse excitation signal, the calibration electrical signal, and the test electrical signal. Therefore, it is possible to directly calibrate the high-frequency current sensor at the transformer operating site without power outage and equipment disassembly, thereby improving the timeliness and flexibility of calibration.

[0029] The technical solutions of this application and how they solve the aforementioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] Figure 1 This is a schematic diagram of the structure of a high-frequency current sensor field calibration system provided in an embodiment of the present invention. Figure 1 As shown, the system includes: a calibration device 1 and a high-frequency calibration current sensor 2; the calibration device 1 is connected to the high-frequency calibration current sensor 2 via a cable, the high-frequency calibration current sensor 2 is installed at the grounding connection bar where the high-frequency current sensor 3 under test is located, the high-frequency current sensor 3 under test is connected to the high-frequency monitoring device 4 via a cable, and the high-frequency monitoring device 4 is electrically connected to the calibration device 1. The calibration device 1 is used to output multiple sets of pulse excitation signals with different amplitudes to the high-frequency calibration current sensor 2, and to collect the calibration electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor 2, as well as to acquire the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency monitoring device 4. The test electrical signal is generated based on the electromagnetic effect between the high-frequency current sensor 3 under test and the grounding connection bar. The calibration device 1 is also used to calculate the reference electrical signal of the high-frequency current sensor 3 under test corresponding to each set of pulse excitation signals based on each set of pulse excitation signals and the calibration electrical signal corresponding to each set of pulse excitation signals. The calibration device 1 is also used to fit and compare the reference electrical signals corresponding to multiple sets of pulse excitation signals with the electrical signals to be tested, and output the calibration results of the high-frequency current sensor 3 to be tested.

[0031] In this embodiment, the high-frequency current sensor 3 under test refers to a high-frequency current sensor that has been installed on the grounding wire of the transformer in the field and is in operation. Its performance parameters (sensitivity, linearity, dynamic range, channel consistency, etc.) are unknown or need to be evaluated, and it is the verification object of this system. The high-frequency calibration current sensor 2 refers to the reference device for field verification. In this system, it serves as an excitation-feedback composite device.

[0032] The pulse excitation signal is an adjustable signal in terms of both frequency and amplitude. For example, the frequency of the pulse excitation signal can be adjusted from 50 Hz to 10 kHz, the amplitude can be adjusted from 0.3 V to 200 V, and the rise time of the pulse excitation signal is less than 10 ns.

[0033] In practical applications, the high-frequency calibration current sensor 2 is installed on the same grounding busbar as the high-frequency current sensor 3 under test. That is, the high-frequency calibration current sensor 2 and the high-frequency current sensor 3 under test are installed on the same grounding busbar, ensuring that they are in the same magnetic field space, thus enabling non-disassembly calibration of the high-frequency current sensor 3 under test during operation. Optionally, in one example, the aforementioned grounding busbar is a transformer grounding copper busbar.

[0034] In practical applications, the calibration device 1 outputs multiple sets of pulse excitation signals of different amplitudes to the high-frequency calibration current sensor 2. Correspondingly, the high-frequency calibration current sensor 2 and the high-frequency current sensor under test 3 generate calibration and test signals respectively in response to their surrounding magnetic fields. The surrounding magnetic fields of the high-frequency calibration current sensor 2 and the high-frequency current sensor under test 3 are generated in response to the pulse excitation signals.

[0035] Optionally, in one possible implementation, the high-frequency calibration current sensor 2 converts the received pulse excitation signal into a first magnetic field. The grounding busbar further converts the first magnetic field into a grounding busbar electrical signal and generates a changing second magnetic field around the grounding busbar. In conjunction with the above description, the high-frequency calibration current sensor 2 and the high-frequency current sensor 3 under test are mounted on the same grounding busbar. The high-frequency current sensor 3 under test generates a test signal in response to the second magnetic field. The high-frequency calibration current sensor 2 generates a verification signal in response to the combined magnetic field of the first and second magnetic fields.

[0036] Optionally, in one possible implementation, the high-frequency calibration current sensor 2 includes a magnetic core, and a calibration coil and a verification coil wound on the magnetic core; The calibration signal is generated by the calibration coil in response to the combined magnetic field around it; the combined magnetic field includes a first magnetic field generated by the calibration coil in response to the pulse excitation signal in the magnetic core, and a second magnetic field generated by the grounding connection bar in response to the first magnetic field; The electrical signal to be tested is generated by the high-frequency current sensor under test in response to the second magnetic field.

[0037] Preferably, in one possible implementation, the magnetic core is made of nanocrystalline alloy strip; and / or, the calibration coil and the verification coil are wound with silver wire.

[0038] For example, the high-frequency calibration current sensor 2 uses nanocrystalline alloy strip, whose magnetic permeability is 3-5 times higher than that of traditional silicon steel sheets. For instance, its loss is as low as 0.1W / kg at 30MHz, improving the magnetic flux conversion efficiency. The magnetic core surface is treated with an insulating coating, such as epoxy resin, with a thickness of 50μm, to prevent core corrosion in humid environments. The calibration coil and verification coil use silver wire, such as silver wire with a diameter of 0.1-0.2mm, wound by a fully automatic winding machine to ensure that the coil turn deviation is ≤±1 turn. The coil frame uses high-temperature resistant polyimide material, such as polyimide material with a temperature resistance of 200℃, to avoid the risk of coil short circuit due to frame deformation during long-term operation. The calibration coil is connected to the BNC (Bayonet Neill-Conceiman) connector of the calibration interface of the high-frequency calibration current sensor 2, and the verification coil is connected to the BNC connector of the output interface of the high-frequency calibration current sensor 2, realizing the multi-functional application of the high-frequency calibration current sensor 2.

[0039] Further, the calibration device 1 acquires the calibration electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor 2. The high-frequency monitoring device 4 acquires the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency current sensor 3 under test, and transmits the test electrical signal corresponding to each set of pulse excitation signals to the calibration device 1. Correspondingly, the calibration device 1 acquires the test electrical signal corresponding to each set of pulse excitation signals and transmits it to the calibration device 1.

[0040] Furthermore, the calibration device 1 calculates the reference electrical signal of the high-frequency current sensor 3 under test corresponding to each set of pulse excitation signals based on each set of pulse excitation signals and the calibration electrical signal corresponding to each set of pulse excitation signals.

[0041] Optionally, in one possible implementation, the above-mentioned verification device 1 is specifically used for: Based on each set of pulse excitation signals and the corresponding verification electrical signal, calculate the loss correction coefficient of the grounding connection bar under each set of pulse excitation signals and the magnetic flux generated by the magnetic field of the grounding connection bar. Based on the calibration coefficient of the high-frequency current sensor 3 under test, the loss correction coefficient of the grounding connection bar under each set of pulse excitation signals, and the magnetic flux generated by the magnetic field of the grounding connection bar, the reference electrical signal of the high-frequency current sensor 3 under test under each set of pulse excitation signals is calculated.

[0042] In practical applications, the calibration device 1 is based on the pulse excitation signal. U in The verification electrical signal corresponding to the pulse excitation signal Calculate the core loss correction coefficient of the high-frequency calibration current sensor 2 under pulse excitation signal. Loss correction factor for grounding connection bus And the magnetic flux generated by the grounding connection magnetic field .

[0043] Furthermore, the calibration device 1 uses the calibration coefficient of the high-frequency current sensor 3 under test. Loss correction factor for grounding connection busbar under each group of pulse excitation signals And the magnetic flux generated by the grounding connection magnetic field Calculate the reference electrical signal of the high-frequency current sensor 3 under each set of pulse excitation signals.

[0044] Optionally, in one example, the reference electrical signal of the high-frequency current sensor 3 under each set of pulse excitation signals is calculated based on the calibration coefficient of the high-frequency current sensor 3 under test, the loss correction coefficient of the grounding connection bar under each set of pulse excitation signals, and the magnetic flux generated by the magnetic field of the grounding connection bar, including: The reference electrical signal of the high-frequency current sensor under test is calculated using the following formula. :

[0045] in, The calibration coefficients are for the high-frequency current sensor 3 under test. This is the loss correction factor for the grounding connection busbar. The magnetic flux generated by the grounding connection of the magnetic field. The number of coil turns of the high-frequency current sensor 3 under test. Let be the impedance of the high-frequency current sensor 3 under test. For example, the impedance of the high-frequency current sensor 3 under test can be 50Ω.

[0046] It should be noted that the calibration coefficient of the high-frequency current sensor 3 under test... This is a fixed value corresponding to the high-frequency current sensor 3 under test. In practical applications, the calibration coefficient... This can be obtained through pre-calculation. For example, calibration device 1 pre-outputs a set of pulse excitation signals to high-frequency calibration current sensor 2 and acquires the test signal generated by the high-frequency current sensor 3 under test. The verification device 1 calculates the verification coefficient based on the electrical signal to be tested. Specifically, the verification device 1 can obtain the result through calculation. , and For the defined parameters, let = The verification coefficient can be calculated. .

[0047] Furthermore, the calibration device 1 fits and compares the reference electrical signals corresponding to multiple sets of pulse excitation signals with the electrical signals to be tested, and outputs the calibration results of the high-frequency current sensor 3 to be tested.

[0048] Specifically, in one possible implementation, when the above-mentioned verification device 1 is used to fit and compare the reference electrical signals corresponding to multiple sets of pulse excitation signals with the electrical signals to be tested, and outputs the verification result of the high-frequency current sensor 3 to be tested, it is specifically used for: Based on the reference electrical signals corresponding to multiple sets of pulse excitation signals, a reference curve is plotted using a curve fitting algorithm. Based on the electrical signals to be tested corresponding to multiple sets of pulse excitation signals, the measured curve is obtained through a curve fitting algorithm. Calculate the deviation between the reference curve and the measured curve, and determine whether the deviation is greater than the preset verification threshold. If the deviation is greater than the preset verification threshold, the performance of the high-frequency current sensor under test is determined to be abnormal; otherwise, the performance of the high-frequency current sensor under test is determined to be normal. Output the calibration results of the high-frequency current sensor under test, which include the performance judgment results of the high-frequency current sensor under test.

[0049] Understandably, curve fitting algorithms are techniques that find one or more curves to approximate the trend of a given set of data points. The goal is to find an analytical function y=f(x,b) that passes through or approximately passes through a finite sequence of data points (xi,yi). This fitting function is typically obtained using a polynomial function and the least squares method. In this scheme, a reference curve is obtained by fitting a reference electrical signal using curve fitting, and the measured curve is obtained by fitting the electrical signal to be tested.

[0050] After obtaining the reference curve and the measured curve, it is necessary to quantitatively assess the degree of difference between them, i.e., calculate the deviation. In this embodiment, the deviation is defined using the normalized mean absolute percentage error. The specific steps are as follows: Let the discrete sampling points of the reference curve on the time axis be... The sampling points corresponding to the measured curve are ,in , Let be the total number of sampling points. Let the maximum amplitude of the reference curve be denoted as . The minimum amplitude is Then the amplitude range of the reference curve . Deviation Calculate using the following formula:

[0051] The numerator represents the root mean square error between the reference curve and the measured curve, and the denominator is the amplitude range of the reference curve. Multiplying this ratio by a percentage yields the dimensionless deviation. The smaller the value, the closer the two curves are.

[0052] The preset calibration threshold is determined through experimental calibration in this embodiment. At least ten qualified high-frequency current sensors are selected, and their measured curves are obtained under standard pulse excitation. The deviation of each sensor is calculated using the formula described above, resulting in a sequence of qualified deviations. The maximum value of this sequence is taken, and a 20% margin is added to this value as the calibration threshold. Based on extensive experimental statistics, the deviation of qualified sensors typically does not exceed 8%, therefore the calibration threshold is set to 10% by default. Users can also adjust this threshold within the range of 5% to 15% according to actual accuracy requirements.

[0053] If the deviation between the measured curve and the reference curve is greater than the preset verification threshold, the high-frequency current sensor under test is determined to be abnormal; otherwise, it is determined to be normal.

[0054] Understandably, the calibration device 1 calculates the reference electrical signal corresponding to the pulse excitation signal based on the pulse excitation signal and the calibration electrical signal, and generates the on-site calibration result of the high-frequency current sensor by fitting and comparing the reference electrical signal with the electrical signal to be tested. This fully automates the on-site calibration of the high-frequency current sensor, improving the accuracy and efficiency of the on-site calibration of the high-frequency current sensor.

[0055] In this embodiment, the electromagnetic coupling property of the high-frequency calibration current sensor 2 and the grounding connection bar is utilized to generate a magnetic field around the high-frequency calibration current sensor 2 and the high-frequency current sensor 3 under test in response to the pulse excitation signal. The high-frequency calibration current sensor 2 and the high-frequency current sensor 3 under test respectively respond to the magnetic field around them, generating a calibration signal and a test signal. The calibration device 1 generates the on-site calibration result of the high-frequency current sensor based on the pulse excitation signal, the calibration signal, and the test signal.

[0056] It is understood that this embodiment allows for the direct calibration of high-frequency current sensors at the transformer operating site without power outages or equipment disassembly, and without waiting for power outage maintenance windows when the transformer is in normal operation. This effectively solves the problem of power outage time limitations in existing methods, greatly reduces the impact of high-frequency current sensor calibration on the normal operation of the power system, improves the timeliness and flexibility of calibration, and enhances the reliability of the power system.

[0057] It should be noted that there are multiple ways to implement the verification device 1. For example, it can be implemented by a physical device that integrates or installs relevant computer programs, such as a server, computer, or measurement and control host.

[0058] Preferably, in one possible implementation, Figure 2 This is a schematic diagram of another high-frequency current sensor field calibration system provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the calibration device 1 includes a pulse signal output unit 11, a signal acquisition unit 12, and a processing unit 13. The high-frequency monitoring device 4 is connected to the high-frequency current sensor 3 under test via a coaxial cable (e.g., a 50Ω coaxial cable). The high-frequency monitoring device 4 is electrically connected (or communicatively connected) to the signal acquisition unit 12. The high-frequency calibration current sensor 2 and the high-frequency current sensor 3 under test are connected to the same grounding wire. The calibration interface of the high-frequency calibration current sensor 2 is connected to the high-frequency signal output interface of the calibration device 1 via a coaxial cable (e.g., a 50Ω coaxial cable), and the output interface of the high-frequency calibration current sensor 2 is connected to the high-frequency signal input interface of the calibration device 1 via a coaxial cable (e.g., a 50Ω coaxial cable). The high-frequency monitoring device 4 is used to monitor the high-frequency current sensor 3 under test and acquire the electrical signal to be tested. The signal acquisition unit 12 acquires the electrical signal to be tested from the high-frequency monitoring device 4.

[0059] like Figure 2 As shown, the pulse signal output unit 11 is connected to the processing unit 13 and the high-frequency calibration current sensor 2. The pulse signal output unit 11 is used to respond to the control command issued by the processing unit 13 and output multiple sets of pulse excitation signals with different amplitudes to the high-frequency calibration current sensor 2. The signal acquisition unit 12 is connected to the high-frequency calibration current sensor 2 and the high-frequency monitoring device 4. The signal acquisition unit 12 is used to acquire the verification electrical signal corresponding to each group of pulse excitation signals returned by the high-frequency calibration current sensor 2, and to acquire the electrical signal to be tested corresponding to each group of pulse excitation signals generated by the high-frequency current sensor 3 under test acquired by the high-frequency monitoring device 4. The processing unit 13 is also connected to the signal acquisition unit 12. The processing unit 13 is used to calculate the reference electrical signal of the high-frequency current sensor 3 under test corresponding to each group of pulse excitation signals and the corresponding verification electrical signal based on each group of pulse excitation signals; and to fit and compare the reference electrical signals corresponding to multiple groups of pulse excitation signals with the electrical signals under test, and output the verification result of the high-frequency current sensor 3 under test.

[0060] Preferably, in one possible implementation, the processing unit 13 is a measurement and control host, which includes an industrial control computer and industrial control software.

[0061] Optionally, in one possible implementation, the pulse signal output unit 11, the signal acquisition unit 12, and the processing unit 13 are encapsulated within the calibration device 1. The calibration interface of the high-frequency calibration current sensor 2 is connected to the output interface of the calibration device 1 via a 50Ω coaxial cable, and the output interface of the high-frequency calibration current sensor 2 is connected to the input interface of the calibration device 1 via a 50Ω coaxial cable. The output interface of the calibration device 1 is connected to the output interface of the pulse signal output unit 11, and the input interface of the calibration device 1 is connected to the input interface of the signal acquisition unit 12.

[0062] Optionally, in one possible implementation, the output interface of the pulse signal output unit 11 and the input interface of the signal acquisition unit 12 are disposed on the surface of the calibration device 1. The calibration interface of the high-frequency calibration current sensor 2 is connected to the output interface of the pulse signal output unit 11 via a 50Ω coaxial cable, and the output interface of the high-frequency calibration current sensor 2 is connected to the input interface of the signal acquisition unit 12 via a 50Ω coaxial cable.

[0063] Specifically, the processing unit 13 sends a control command to the pulse signal output unit 11. Correspondingly, the pulse signal output unit 11 responds to the control command sent by the processing unit 13 and outputs multiple sets of pulse excitation signals with different amplitudes to the high-frequency calibration current sensor 2.

[0064] In practical applications, before the high-frequency current sensor calibrator 3 under test is calibrated on-site, the high-frequency calibration current sensor 2 also needs to be configured and calibrated. The following example uses a transformer grounding copper busbar as an illustration.

[0065] Optionally, in one possible implementation, when the high-frequency calibration current sensor 2 is not inserted into the transformer grounding copper busbar, the pulse signal output unit 11 responds to the verification command issued by the processing unit 13 and outputs a verification pulse excitation signal to the high-frequency calibration current sensor 2.

[0066] The high-frequency calibration current sensor 2 converts the calibration pulse excitation electrical signal into a third magnetic field. The magnetic flux Φ generated by the magnetic core of the high-frequency calibration current sensor 2 is related to the magnetic permeability of the magnetic core. Effective cross-sectional area of ​​magnetic core and effective length of magnetic circuit And related to the magnetizing field H, the formula for calculating the magnetic flux Φ generated by the magnetic core is:

[0067]

[0068] Where Φ is the magnetic flux generated by the magnetic core, which characterizes the magnitude of the magnetic flux through the effective cross-sectional area of ​​the magnetic core. is the complex permeability of the magnetic core, which characterizes the core's ability to conduct magnetic fields at different frequencies, and includes a real part (permeability) and an imaginary part (loss). The effective cross-sectional area of ​​the magnetic core represents the cross-sectional area of ​​the region in the magnetic core where the magnetic field is uniformly distributed. The effective length of the magnetic circuit represents the average length of the closed path of the magnetic field inside the magnetic core. The number of turns of the calibration coil, i.e. the number of turns of the wire wound in the calibration coil of the high-frequency calibration current sensor 2. As the excitation current, the pulse signal output unit 11 inputs the current value corresponding to the verification pulse excitation signal of the calibration coil. To verify the amplitude of the pulse excitation signal. For example, to calibrate the impedance of current sensor 2 at high frequency, It is 50Ω.

[0069] At this point, the calibration coil in the high-frequency calibration current sensor 2 further converts the third magnetic field into a first electric field signal, and outputs the first electric field signal. The magnetic flux Φ generated by the magnetic core and the number of turns of the calibration coil Related, first electric field signal The expression is as follows:

[0070] Where Φ is the magnetic flux generated by the magnetic core, which characterizes the magnitude of the magnetic flux through the effective cross-sectional area of ​​the magnetic core. To verify the number of turns of the coil, that is, the number of turns of the wire wound in the verification coil of the high-frequency calibration current sensor 2. The impedance of current sensor 2 is calibrated for high frequency. This is the core loss correction factor. In practice, The calibration device 1 can automatically calculate the current without the transformer grounding copper busbar by using the configured high-frequency calibration current sensor 2.

[0071] After the high-frequency calibration current sensor 2 is inserted into the transformer grounding copper busbar, the transformer grounding copper busbar will convert the third magnetic field into a second electric field signal, and the output second electric field signal will be generated. The magnetic flux passing through the copper busbar generates a magnetic field signal (third magnetic field) with the magnetic core. and copper busbar cross-sectional area Related, second electric field signal The calculation formula is:

[0072] in, The magnetic flux through the copper busbar is the magnetic flux that generates the magnetic field signal from the magnetic core. It characterizes the magnitude of the magnetic flux generated by the magnetic core through the effective cross-sectional area of ​​the copper busbar. Let be the cross-sectional area of ​​the copper busbar. The impedance coefficient of the copper busbar can be determined based on the cross-sectional area of ​​the copper busbar, and is generally selected in the range of 0.1 to 0.3.

[0073] After passing through the transformer grounding copper busbar, the calibration coil of the high-frequency calibration current sensor 2 will simultaneously receive the third magnetic field generated by the magnetic core of the high-frequency calibration current sensor 2 and the fourth magnetic field generated by the second electric field signal. At this time, the third electric field signal output by the high-frequency calibration current sensor 2... The magnetic flux Φ that generates the magnetic field with the magnetic core and the magnetic flux that generates the magnetic field with the transformer grounding copper busbar. And verify the number of coil turns Related:

[0074]

[0075]

[0076] in, This represents the induced current in the copper busbar. The magnetic flux generated by the magnetic field of the copper busbar represents the magnitude of the magnetic flux generated by the copper busbar passing through the effective cross-sectional area of ​​the magnetic core. To verify the number of turns of the coil, that is, the number of turns of the wire wound in the verification coil of the high-frequency calibration current sensor 2. To calibrate the impedance of current sensor 2 at high frequency, This is the core loss correction factor. This is the loss correction factor for the transformer grounding copper busbar.

[0077] Based on this, the high-frequency current sensor field calibration system can perform on-site calibration of the high-frequency current sensor 3 under test. Specifically, the calibration device 1, based on the configured high-frequency calibration current sensor 2 passing through the copper busbar, outputs multiple sets (e.g., 4 sets) of pulse excitation signals with different amplitudes through the pulse signal output unit 11. Correspondingly, the signal acquisition unit 12 obtains the calibration electrical signal and the electrical signal under test corresponding to each set of pulse excitation signals. U p The processing unit 13 acquires the verification electrical signal and the electrical signal to be tested corresponding to each group of pulse excitation signals. U p The processing unit 13 calculates the reference electrical signal of the high-frequency current sensor under test corresponding to each set of pulse excitation signals based on each set of pulse excitation signals and the corresponding verification electrical signal. U p1 The processing unit 13 processes the reference electrical signals corresponding to multiple sets of pulse excitation signals. U p1 With the electrical signal to be tested U pPerform fitting and comparison to determine whether the performance of the high-frequency current sensor 3 under test meets the requirements, and output the verification result of the high-frequency current sensor under test.

[0078] In addition, in one possible implementation, the processing unit 13 is also used to generate a verification report, which includes the field verification results of the high-frequency current sensor.

[0079] In this embodiment, after generating the on-site verification results of the high-frequency current sensor, the processing unit 13 generates a verification report, which facilitates management by staff, improves the efficiency and accuracy of transformer monitoring, and enhances the reliability of the power system.

[0080] In addition, in one possible implementation, the above-mentioned high-frequency current sensor field calibration system also includes a touch screen display. Processing unit 13 is also used to draw waveforms of pulse excitation signal, verification signal, and signal under test; The touch screen is connected to the processing unit 13. The touch screen is used to visualize the on-site calibration results of the high-frequency current sensor, as well as the waveforms of the pulse excitation signal, calibration signal, and signal under test.

[0081] In this embodiment, after generating the on-site verification results of the high-frequency current sensor, the processing unit 13 visualizes the performance judgment results and the waveforms of the pulse excitation signal, the verification signal, and the signal to be tested, which facilitates management by staff, improves the efficiency and accuracy of transformer monitoring, and enhances the reliability of the power system.

[0082] Optionally, in one example, the touchscreen supports human-computer interaction, allowing operators to set the performance parameters to be calibrated for the high-frequency current sensor 3 under test on the touchscreen's control interface. For example, these performance parameters include, but are not limited to, sensitivity, linearity, dynamic range, and channel consistency. The high-frequency current sensor field calibration system can automatically complete the calibration of the high-frequency current sensor 3 under test based on the set performance parameters, automatically generate a calibration report, or visually display the performance judgment results, greatly reducing manual operation and human error, and improving the efficiency and quality of the calibration work.

[0083] Optionally, in one possible implementation, the signal acquisition unit 12 incorporates a high-precision current transformer, capable of accurately measuring minute changes in high-frequency current. The processing unit 13 incorporates a digital signal processor, ensuring that the accuracy of the verification results meets industry standard requirements.

[0084] Optionally, to improve anti-interference capability, in one possible implementation, the high-frequency current sensor field calibration system further includes an anti-interference device. For example, the anti-interference circuit includes electromagnetic shielding, filtering circuits, etc. By optimizing the hardware design and software algorithm of the anti-interference device, external interference signals can be effectively suppressed, and current signals can still be accurately acquired and processed in complex electromagnetic environments. For instance, by using metal shielding material for the anti-interference device housing and setting up multi-layer filtering circuits internally, high-frequency interference signals from the outside can be effectively filtered out, ensuring that the calibration results are not affected by interference.

[0085] In this embodiment of the invention, the high-frequency calibration current sensor 2 is installed at the grounding connection bar where the high-frequency current sensor 3 under test is located. The calibration device 1 outputs multiple sets of pulse excitation signals of different amplitudes to the high-frequency calibration current sensor 2, and acquires the calibration electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor 2, as well as the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency monitoring device 4. The test electrical signal is generated based on the electromagnetic effect between the high-frequency current sensor 3 under test and the grounding connection bar. The calibration device 1 calculates the reference electrical signal of the high-frequency current sensor under test corresponding to each set of pulse excitation signals based on each set of pulse excitation signals and the corresponding calibration electrical signal. The calibration device 1 fits and compares the reference electrical signals corresponding to multiple sets of pulse excitation signals with the test electrical signals, and outputs the calibration result of the high-frequency current sensor under test.

[0086] Therefore, this invention allows for the direct calibration of high-frequency current sensors at the transformer operating site without power outages or equipment disassembly, and without waiting for power outage maintenance windows, when the transformer is in normal operation. This effectively solves the problem of power outage time limitations in existing methods, greatly reduces the impact of high-frequency current sensor calibration on the normal operation of the power system, improves the timeliness and flexibility of calibration, and enhances the reliability of the power system.

[0087] The following are method embodiments of the present invention. For details not described in detail, please refer to the corresponding system embodiments described above.

[0088] Figure 3 This is a flowchart illustrating the implementation of a field verification method for a high-frequency current sensor provided in an embodiment of the present invention. This method is applied to the verification system provided in the above embodiment. Figure 3 As shown, the method includes the following steps: Step 501: Output multiple sets of pulse excitation signals with different amplitudes to the high-frequency calibration current sensor, and collect the verification electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor, as well as the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency current sensor under test, which is collected by the high-frequency monitoring device. The test electrical signal is generated based on the electromagnetic effect between the high-frequency current sensor under test and the grounding connection bar. Step 502: Calculate the reference electrical signal of the high-frequency current sensor under test corresponding to each group of pulse excitation signals based on each group of pulse excitation signals and the corresponding verification electrical signal. Step 503: Fit and compare the reference electrical signals corresponding to the multiple sets of pulse excitation signals with the electrical signals to be tested, and output the verification results of the high-frequency current sensor to be tested.

[0089] In one possible implementation, step 502 specifically includes: Based on each set of pulse excitation signals and the corresponding verification electrical signals, calculate the core loss correction coefficient, the grounding connection bar loss correction coefficient, and the magnetic flux generated by the grounding connection bar magnetic field of the high-frequency calibration current sensor under each set of pulse excitation signals. The calibration coefficient of the high-frequency current sensor under test is calculated based on the electrical signal to be tested corresponding to each set of pulse excitation signals, the core loss correction coefficient of the high-frequency calibration current sensor under each set of pulse excitation signals, the loss correction coefficient of the grounding connection bar, and the magnetic flux generated by the magnetic field of the grounding connection bar. Based on the calibration coefficient of the high-frequency current sensor under test under each set of pulse excitation signals, the reference electrical signal of the high-frequency current sensor under test under each set of pulse excitation signals is calculated.

[0090] In one possible implementation, based on the calibration coefficient of the high-frequency current sensor under test under each set of pulse excitation signals, a reference electrical signal of the high-frequency current sensor under test under each set of pulse excitation signals is calculated, including: The reference electrical signal of the high-frequency current sensor under test is calculated using the following formula. :

[0091] in, The calibration coefficient is the high-frequency current sensor under test. This is the loss correction factor for the grounding connection busbar. The magnetic flux generated by the grounding connection of the magnetic field. The number of coil turns of the high-frequency current sensor under test. The impedance of the high-frequency current sensor under test is given.

[0092] In one possible implementation, step 503 specifically includes: Based on the reference electrical signals corresponding to multiple sets of pulse excitation signals, a reference curve is plotted using a curve fitting algorithm. Based on the electrical signals to be tested corresponding to multiple sets of pulse excitation signals, the measured curve is obtained through a curve fitting algorithm. Calculate the deviation between the reference curve and the measured curve, and determine whether the deviation is greater than the preset verification threshold. If the deviation is greater than the preset verification threshold, the performance of the high-frequency current sensor under test is determined to be abnormal; otherwise, the performance of the high-frequency current sensor under test is determined to be normal. Output the calibration results of the high-frequency current sensor under test, which include the performance judgment results of the high-frequency current sensor under test.

[0093] In this embodiment of the invention, the high-frequency calibration current sensor is installed at the grounding connection bar where the high-frequency current sensor under test is located. The calibration device outputs multiple sets of pulse excitation signals of different amplitudes to the high-frequency calibration current sensor, and acquires the calibration electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor, as well as the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency monitoring device. The test electrical signal is generated based on the electromagnetic effect between the high-frequency current sensor under test and the grounding connection bar. The calibration device calculates the reference electrical signal of the high-frequency current sensor under test corresponding to each set of pulse excitation signals based on each set of pulse excitation signals and the corresponding calibration electrical signal. The calibration device fits and compares the reference electrical signals corresponding to multiple sets of pulse excitation signals with the test electrical signals, and outputs the calibration result of the high-frequency current sensor under test.

[0094] Therefore, this invention allows for the direct calibration of high-frequency current sensors at the transformer operating site without power outages or equipment disassembly, and without waiting for power outage maintenance windows, when the transformer is in normal operation. This effectively solves the problem of power outage time limitations in existing methods, greatly reduces the impact of high-frequency current sensor calibration on the normal operation of the power system, improves the timeliness and flexibility of calibration, and enhances the reliability of the power system.

[0095] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0096] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A field calibration system for a high-frequency current sensor, characterized in that, The system includes a calibration device and a high-frequency calibration current sensor. The calibration device is connected to the high-frequency calibration current sensor via a cable. The high-frequency calibration current sensor is installed at the grounding connection bar where the high-frequency current sensor under test is located. The high-frequency current sensor under test is connected to the high-frequency monitoring device via a cable. The calibration device is used to output multiple sets of pulse excitation signals with different amplitudes to the high-frequency calibration current sensor, and to collect the calibration electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor, and to acquire the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency current sensor under test, which is collected by the high-frequency monitoring device. The test electrical signal is generated based on the electromagnetic effect between the high-frequency current sensor under test and the grounding connection bar. The verification device is also used to calculate the reference electrical signal of the high-frequency current sensor under test corresponding to each set of pulse excitation signals based on each set of pulse excitation signals and the verification electrical signal corresponding to each set of pulse excitation signals. The verification device is also used to fit and compare the reference electrical signals corresponding to multiple sets of pulse excitation signals with the electrical signals to be tested, and output the verification result of the high-frequency current sensor to be tested.

2. The high-frequency current sensor field calibration system according to claim 1, characterized in that, The verification device is specifically used for: Based on each set of pulse excitation signals and the corresponding verification electrical signal, calculate the loss correction coefficient of the grounding connection bar under each set of pulse excitation signals and the magnetic flux generated by the magnetic field of the grounding connection bar. Based on the calibration coefficient of the high-frequency current sensor under test, the loss correction coefficient of the grounding connection bar under each set of pulse excitation signals, and the magnetic flux generated by the magnetic field of the grounding connection bar, the reference electrical signal of the high-frequency current sensor under test under each set of pulse excitation signals is calculated.

3. The high-frequency current sensor field calibration system according to claim 2, characterized in that, The step of calculating the reference electrical signal of the high-frequency current sensor under each pulse excitation signal based on the calibration coefficient of the high-frequency current sensor under test, the loss correction coefficient of the grounding connection busbar under each set of pulse excitation signals, and the magnetic flux generated by the magnetic field of the grounding connection busbar includes: The reference electrical signal of the high-frequency current sensor under test is calculated using the following formula. : in, The calibration coefficient is the high-frequency current sensor under test. This is the loss correction factor for the grounding connection busbar. The magnetic flux generated by the grounding connection of the magnetic field. The number of coil turns of the high-frequency current sensor under test. The impedance of the high-frequency current sensor under test is given.

4. The high-frequency current sensor field calibration system according to claim 1, characterized in that, The calibration device is used to fit and compare the reference electrical signals corresponding to multiple sets of pulse excitation signals with the electrical signals to be tested, and outputs the calibration result of the high-frequency current sensor under test. Specifically, it is used for: Based on the reference electrical signals corresponding to multiple sets of pulse excitation signals, a reference curve is plotted using a curve fitting algorithm. Based on the electrical signals to be tested corresponding to multiple sets of pulse excitation signals, the measured curve is obtained through a curve fitting algorithm. Calculate the deviation between the reference curve and the measured curve, and determine whether the deviation is greater than a preset verification threshold. If the deviation is greater than the preset verification threshold, the performance of the high-frequency current sensor under test is determined to be abnormal. Otherwise, the performance of the high-frequency current sensor under test is determined to be normal. Output the verification result of the high-frequency current sensor under test, which includes the performance judgment result of the high-frequency current sensor under test.

5. The high-frequency current sensor field calibration system according to claim 1, characterized in that, The high-frequency calibration current sensor includes a magnetic core, and a calibration coil and a verification coil wound on the magnetic core; The verification signal is generated by the verification coil in response to the combined magnetic field around it; the combined magnetic field includes a first magnetic field generated by the calibration coil in response to the pulse excitation signal in the magnetic core, and a second magnetic field generated by the grounding connection bar in response to the first magnetic field; The electrical signal to be tested is generated by the high-frequency current sensor under test in response to the second magnetic field.

6. The high-frequency current sensor field calibration system according to claim 1, characterized in that, The frequency adjustment range of the pulse excitation signal is 50Hz to 10kHz, the amplitude adjustment range of the pulse excitation signal is 0.3V to 200V, and the rise time of the pulse excitation signal is less than 10ns.

7. A method for on-site verification of a high-frequency current sensor, characterized in that, The method is applied to the verification system as described in any one of claims 1-6, and the method includes: Multiple sets of pulse excitation signals with different amplitudes are output to the high-frequency calibration current sensor, and the verification electrical signal corresponding to each set of pulse excitation signals returned by the high-frequency calibration current sensor is collected, as well as the test electrical signal corresponding to each set of pulse excitation signals generated by the high-frequency current sensor under test is acquired by the high-frequency monitoring device. The test electrical signal is generated based on the electromagnetic effect between the high-frequency current sensor under test and the grounding connection bar. Based on each set of pulse excitation signals and the corresponding verification electrical signal, calculate the reference electrical signal of the high-frequency current sensor under test corresponding to each set of pulse excitation signals; The reference electrical signals corresponding to multiple sets of pulse excitation signals are fitted and compared with the electrical signals to be tested, and the verification results of the high-frequency current sensor to be tested are output.

8. The on-site verification method for a high-frequency current sensor according to claim 7, characterized in that, The step of calculating the reference electrical signal of the high-frequency current sensor under test corresponding to each set of pulse excitation signals based on each set of pulse excitation signals and the corresponding verification electrical signal specifically includes: Based on each set of pulse excitation signals and the corresponding verification electrical signal, calculate the core loss correction coefficient, the grounding connection bar loss correction coefficient, and the magnetic flux generated by the grounding connection bar magnetic field of the high-frequency calibration current sensor under each set of pulse excitation signals. The calibration coefficient of the high-frequency current sensor under test is calculated based on the electrical signal to be tested corresponding to each set of pulse excitation signals, the core loss correction coefficient of the high-frequency calibration current sensor under each set of pulse excitation signals, the loss correction coefficient of the grounding connection bar, and the magnetic flux generated by the magnetic field of the grounding connection bar. Based on the calibration coefficient of the high-frequency current sensor under test under each set of pulse excitation signals, the reference electrical signal of the high-frequency current sensor under test under each set of pulse excitation signals is calculated.

9. The on-site verification method for a high-frequency current sensor according to claim 8, characterized in that, The calculation of the reference electrical signal of the high-frequency current sensor under test based on the calibration coefficient of the high-frequency current sensor under each set of pulse excitation signals includes: The reference electrical signal of the high-frequency current sensor under test is calculated using the following formula. : in, The calibration coefficient is the high-frequency current sensor under test. This is the loss correction factor for the grounding connection busbar. The magnetic flux generated by the grounding connection of the magnetic field. The number of coil turns of the high-frequency current sensor under test. The impedance of the high-frequency current sensor under test is given.

10. The on-site verification method for a high-frequency current sensor according to claim 7, characterized in that, The step of fitting and comparing the reference electrical signals corresponding to multiple sets of pulse excitation signals with the electrical signals to be tested, and outputting the verification result of the high-frequency current sensor to be tested, specifically includes: Based on the reference electrical signals corresponding to multiple sets of pulse excitation signals, a reference curve is plotted using a curve fitting algorithm. Based on the electrical signals to be tested corresponding to multiple sets of pulse excitation signals, the measured curve is obtained through a curve fitting algorithm. Calculate the deviation between the reference curve and the measured curve, and determine whether the deviation is greater than a preset verification threshold. If the deviation is greater than the preset verification threshold, the performance of the high-frequency current sensor under test is determined to be abnormal; otherwise, the performance of the high-frequency current sensor under test is determined to be normal. Output the verification result of the high-frequency current sensor under test, which includes the performance judgment result of the high-frequency current sensor under test.

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