High-precision calibration method and device for Rogowski coil used in pulsed high-current source measurement

Abstract

The present invention discloses a high-precision calibration method for Rogowski coils used in pulsed high-current source measurements, and the steps are as follows: S1. Build an adjustable precision current test source at the hundred-ampere level; S2. Build a calibration test system for the Rogowski coil scale factor; S3. Calibrate the current amplitude of the Rogowski coil scale factor; S4. Calibrate the frequency of the Rogowski coil line scale factor; S5. Verify after calibrating the Rogowski coil line scale factor. The present application also discloses a device for implementing the high-precision calibration method for Rogowski coils used in pulsed high-current source measurements. The present application uses a precision small current source to replace the traditional high-power pulsed current source as the calibration source, which can effectively reduce the requirements for test equipment, the test difficulty, and the test safety; by using a refined calibration method that combines the calibration of the current amplitude and the frequency of the Rogowski coil scale factor, the influence of the amplitude and frequency changes in pulsed measurements on the measurement accuracy can be effectively reduced. Compared with traditional calibration, the calibration accuracy of the Rogowski coil can be significantly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pulsed high - current source measurement, and specifically to a high - precision calibration method and device for Rogowski coils used in pulsed high - current source measurement. Background Art

[0002] High - power pulsed electrical energy sources are key components of electromagnetic launch equipment, featuring high voltage (above several thousand volts), large current (above several thousand amperes), fast pulses (micro - to nano - seconds), high power (in the megawatt range), etc. The parameters such as the amplitude characteristics, phase characteristics, and frequency characteristics of the current in the pulse - forming network (PFN) of high - power pulsed electrical energy sources are indicators for measuring the performance of high - power pulsed electrical energy sources. By measuring these characteristics, the discharge circuit of the entire high - power pulsed electrical energy source can be simulated, verified, optimized in design, and accurately evaluated for performance. How to measure the ultimate electrical performance of high - power pulsed electrical energy sources is one of the problems that urgently need to be solved currently.

[0003] Furthermore, for the measurement of the MW - level PFN discharge circuit, the most commonly used measurement method at present is to use a Rogowski coil as the front - end current sensor. By setting the integration method and using a high - precision acquisition device to collect the current signal, the current of the discharge circuit is obtained by inversely calculating based on the calibration factor given before the Rogowski coil leaves the factory. Although the amplitude range and measurement frequency of the Rogowski coil meet the measurement requirements of the PFN discharge circuit, the measurement error generated by the method of solving the current based on a fixed calibration factor is usually above 1%, which cannot meet the actual test requirements. How to reduce the measurement error of the Rogowski coil is one of the key technologies for PFN discharge circuit measurement.

[0004] Furthermore, the traditional method for improving the measurement accuracy of Rogowski coils is to calibrate the calibration factor of the Rogowski coil. The calibration method usually selects a coaxial shunt connected in series in the PFN discharge circuit. By measuring the voltage across the coaxial shunt and comparing the measured output of the Rogowski coil to calibrate the actual calibration factor. The calibrated calibration factor is more in line with the measurement site conditions. Therefore, this method can improve the measurement accuracy of Rogowski coils to a certain extent. However, the existing calibration means have the following several disadvantages:

[0005] (1) The calibration accuracy is relatively low. The high - power pulsed electrical energy source requires the measurement accuracy of the Rogowski coil to be within 5‰, and the calibration accuracy of this calibration method cannot meet the requirements;

[0006] (2) The applicability of the scale factor under the single-frequency condition is poor. In actual measurements, due to the combined influence of the self-characteristics of the Rogowski coil and the conditioning circuit, the scale factor of the Rogowski coil varies greatly under different frequency conditions. The scale factor calibration method under the fixed-frequency condition has good results in the measurement of 50Hz power frequency large current, but it cannot meet the high-precision measurement requirements of the measurement object with a wide spectrum component distribution such as the PFN discharge circuit. Therefore, how to reduce the influence of frequency on the scale factor is another difficult problem in solving the measurement of the PFN discharge circuit.

[0007] Regarding the fact that there are few MW-level power pulse power sources for calibration, and the measurement method of connecting shunt resistors in series has great installation difficulty for calibration tests, and it is easy to have adverse factors on the test personnel and test equipment. How to improve the safety of test personnel and test equipment is one of the key points in the calibration of Rogowski coils. Summary of the Invention

[0008] The purpose of the embodiments of the present invention is to provide a high-precision calibration method and equipment for Rogowski coils used in the measurement of pulsed high currents to solve the above problems.

[0009] To achieve the above purpose, the present invention provides the following technical solutions:

[0010] A high-precision calibration method for Rogowski coils used in the measurement of pulsed high currents, the steps are as follows:

[0011] S1. Build an adjustable precision current test source of hundreds of amperes:

[0012] A high-power precision current generating source is composed of a signal generator and a precision power amplifier. At the same time, a low-temperature-drift precision resistor is used as the load resistor to build a precision current test source. The output channel of the signal generator is connected to the signal input interface of the precision power amplifier. The output terminal of the precision power amplifier is connected in parallel with the load resistor array. By adjusting the signal type, amplitude, and the ratio of the precision power amplifier of the signal generator, the signal type, amplitude characteristics, and frequency characteristics of the current flowing through the load are changed to provide a test source for the linearity calibration and frequency calibration of the Rogowski coil; wind multiple turns of coils on the current loop and pass through the Rogowski coil to increase the maximum primary current flowing through the Rogowski coil to 500A. The induced current of the Rogowski coil is as follows:

[0013]

[0014] Among them, I 总 is the total primary current flowing through the Rogowski coil; N is the number of turns of the coil; V is the voltage across the load resistor; R is the load resistor;

[0015] According to the factory scale factor K, the output amplitude can be obtained:

[0016] V = KI总 ;

[0017] S2. Set up the calibration test system for the Rogowski coil scale factor:

[0018] The calibration test system includes the Rogowski coil under test, a precision current test source of class 100A, a functional digital multimeter, a high-precision data acquisition card, a host computer, and an acquisition and analysis software module. Among them, the probes of the functional digital multimeter are respectively placed at both ends of the load resistor to measure the voltage across the load resistor of the current test source and the resistance at both ends, and obtain the current flowing through the load resistor. The actual current flowing through the Rogowski coil can be calculated according to the number of turns of the coil. The high-precision data acquisition card, the host computer, and the acquisition and analysis software module form the output voltage test unit of the Rogowski coil to collect the amplitude of the output voltage in real time. According to the scale factor calculation formula: K = I in / V out the scale factor value can be calculated; where I in is the primary current and V out is the output voltage of the Rogowski coil;

[0019] S3. Calibrate the current amplitude of the Rogowski coil scale factor:

[0020] Set the input waveform and input frequency of the signal generator, change the proportionality coefficient of the power amplifier to adjust the magnitude of the primary input current, and measure multiple sets of load voltages, load resistors, and the output voltage of the Rogowski coil under different proportionality coefficient conditions and calculate the mean values. Among them, the mean value of the load voltage is the mean value of the load resistor is the mean value of the output voltage of the Rogowski coil is

[0021] According to the primary current calculation formula the mean value of the actual primary current under different magnification conditions can be obtained: According to K = I in / V out the mean value of the scale factor under different current conditions can be calculated:

[0022]

[0023] For the measured and perform linear fitting to obtain the relationship between the scale factor and the change in current amplitude: and calculate the linearity δ of the fitting line. If δ is within 3‰, it indicates that the influence of the change in current amplitude on the scale factor is small, and the method of extrapolating the scale factor under large current conditions using a small current generator is feasible;

[0024] S4. Calibrate the frequency of the Rogowski coil scale factor:

[0025] Input a sine wave as the signal, set the amplifier magnification to a fixed value, change the input frequency of the sine wave at equal intervals, and measure the mean value of the scale factor under different frequency conditions by a similar method as in S3; meanwhile, according to and the corresponding f = [f1, f2, f3, f n perform curve fitting to obtain the relationship between the scale factor and the change in current frequency:

[0026]

[0027] S5. Verification after calibration of the Rogowski coil scale factor:

[0028] By randomly changing the input frequency of the sine wave and measuring the actual current value I flowing through the Rogowski coil 总i and the voltage value output by the Rogowski coil Use the frequency of the input signal to substitute into the frequency fitting curve to solve the theoretical scale factor K i = F(f i ), the measured current value is and calculate the relative error γ:

[0029]

[0030] If the measurement error of the Rogowski coil with a nominal accuracy of 1% after calibration is better than 5‰ under different frequency conditions, it meets the calibration requirements.

[0031] In an alternative solution: in step S1, to ensure that the current and voltage flowing through the load resistor are within the rated range, 25 60Ω high-power aluminum shell resistors are connected in parallel for the low-temperature drift precision resistor, and the total resistance value is controlled at 3Ω, and the maximum allowable current flowing through is 15A; the aluminum shell resistor itself has a heat dissipation function, and at the same time, the parallel aluminum shell resistors are placed on a large-scale heat dissipation copper sheet to avoid excessive resistor temperature.

[0032] In an alternative solution: in step S2, the functional digital multimeter is an eight-and-a-half-digit high-precision digital multimeter; the high-precision data acquisition card is a 16-bit data acquisition card, which is used to reduce the error of the measuring instrument and ensure the accuracy of the measured mean voltage of the sine wave and the load resistor.

[0033] In an alternative solution: in step S2, the upper computer measurement software has functions such as waveform display, waveform spectrum analysis, amplitude measurement, and rise time measurement. When measuring a sine wave, the measured voltage peak value is converted into the voltage effective value for scale factor calculation.

[0034] In an alternative solution: in step S3, the current amplitude varies in the range of 50 A to 500 A, and the frequency of the input signal from the signal source is 100 Hz; if the function linearity δ between the measured amplitude and the scale factor is better than 3‰, the scale factors of the current amplitude variations under various frequency conditions are averaged and used as the fixed scale factor; if the linearity is poor, the influence of the amplitude variation on the scale factor is fitted into a curve, and the error correction is performed on the frequency calibration curve in S4.

[0035] In an alternative solution: in step S4, according to the measurement characteristics of the Rogowski coil, the frequency varies in the range of 100 Hz to 10 KHz during the frequency calibration process, and the equal-spacing interval is 50 Hz; to improve the calibration accuracy, the average value of the measured calibration data is 50 groups.

[0036] In an alternative solution: in steps S3 and S4, the influence of the current amplitude variation on the scale factor can be used as a fixed error correction factor to correct the frequency model, and the correction method is as follows:

[0037] (1) Set the amplitude correction factor as Kv, and the function under the fixed amplitude I f is The corresponding error correction function is

[0038] (2) Kv is calculated as follows:

[0039] ① If the linearity δ of

[0040] is less than 3‰, Kv = 1; the linearity δ of

[0041] In an alternative solution: the specific calibration working process is as follows:

[0042] ① Build a Rogowski coil scale factor calibration test system, and use an oscilloscope to test whether the output signal is distorted;

[0043] ② Set the frequency of the signal source and the amplification factor of the precision amplifier;

[0044] ③ Let the test system work stably for 30 min to ensure the stability of the change in the load resistance value;

[0045] ④ Use a multifunctional digital multimeter to measure the load voltage multiple times, and use the labview software program to collect the output voltage of the Rogowski coil multiple times;

[0046] ⑤ After a single test, cut off the power supply and measure the load resistance value;

[0047] ⑥ Repeat all amplitude and frequency values according to the same measurement steps;

[0048] ⑦ Fit the amplitude change curve and the frequency curve, and verify the accuracy after calibration;

[0049] ⑧ If the accuracy after calibration meets the requirements, the calibration test ends.

[0050] A high-precision calibration device for Rogowski coils used in pulsed high-current source measurement, comprising:

[0051] A memory for storing programs;

[0052] A processor for implementing the steps of the above-mentioned high-precision calibration method for Rogowski coils used in pulsed high-current source measurement when executing the programs stored in the memory.

[0053] A storage medium, on which a computer program is stored, and the computer program is executed by a processor to implement the steps of the above-mentioned high-precision calibration method for Rogowski coils used in pulsed high-current source measurement.

[0054] Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows:

[0055] Using a precision small current source to replace the traditional high-power pulsed current source as the calibration source can effectively reduce the requirements for test equipment, test difficulty, and test safety; at the same time, adopting a refined calibration method that combines the calibration of the Rogowski coil scale factor current amplitude and frequency calibration can effectively reduce the influence of amplitude and frequency changes on the measurement accuracy in pulsed measurement. Compared with traditional calibration, it can significantly improve the calibration accuracy of Rogowski coils. Description of the Drawings

[0056] Figure 1 is a flowchart of a high-precision calibration method for Rogowski coils used in pulsed high-current source measurement according to the first embodiment of the present invention;

[0057] Figure 2 is Figure 1 the structural diagram of the Rogowski coil scale factor calibration test system built in step S2 in

[0058] Figure 3 is the flowchart of the calibration working process.

[0059] In the figure, 101 - signal generator, 102 - precision power amplifier, 103 - load resistor, 201 - Rogowski coil to be measured, 202 - functional digital multimeter, 203 - high-precision data acquisition card, 204 - upper computer, 205 - acquisition and analysis software module Detailed Embodiments

[0060] The following embodiments will describe the present invention in detail with reference to the accompanying drawings. In the drawings or the description, similar or identical parts are denoted by the same reference numerals. Each of the embodiments listed for the present invention is only used to illustrate the present invention and is not intended to limit the scope of the present invention. Any obvious modification or change made to the present invention does not depart from the spirit and scope of the present invention.

[0061] Embodiment 1

[0062] Please refer to Figures 1 to 3 , in the embodiment of the present invention, a high-precision calibration method for a Rogowski coil used in pulsed high-current source measurement is as follows:

[0063] S1. Build an adjustable precision current test source of hundreds of amperes:

[0064] A high-power precision current generating source is composed of a signal generator and a precision power amplifier. At the same time, a precision resistor with low temperature drift is used as the load resistor to build a precision current test source. The output channel of the signal generator is connected to the signal input interface of the precision power amplifier, and the output terminal of the precision power amplifier is connected in parallel with the load resistor array. By adjusting the signal type, amplitude, and the ratio of the precision power amplifier of the signal generator, the signal type, amplitude characteristics, and frequency characteristics of the current flowing through the load are changed, providing a test source for the linearity calibration and frequency calibration of the Rogowski coil; A multi-turn coil 104 is wound around the current loop and passes through the Rogowski coil to increase the maximum primary current flowing through the Rogowski coil to 500 A. The induced current of the Rogowski coil is as follows:

[0065]

[0066] Wherein, I 总 is the total primary current flowing through the Rogowski coil; N is the number of turns of the coil; V is the voltage across the load resistor; R is the load resistor;

[0067] According to the factory calibration factor K, the output amplitude can be obtained:

[0068] V = KI 总 ;

[0069] S2. Build a calibration test system for the Rogowski coil calibration factor:

[0070] The calibration test system includes a Rogowski coil under test, a precision current test source of 100A class, a functional digital multimeter, a high-precision data acquisition card, a host computer, and a collection and analysis software module. Among them, the probes of the functional digital multimeter are respectively placed at both ends of the load resistor to measure the voltage and resistance at both ends of the load resistor of the current test source, and obtain the current flowing through the load resistor. The actual current flowing through the Rogowski coil can be calculated according to the number of turns of the coil. The high-precision data acquisition card, the host computer, and the collection and analysis software module form a Rogowski coil output voltage test unit to collect the output voltage amplitude in real time. According to the scale factor calculation formula: K = I in / V out the scale factor value can be calculated, where I in is the primary current and V out is the output voltage of the Rogowski coil;

[0071] S3. Calibration of the current amplitude of the Rogowski coil scale factor:

[0072] Set the input waveform and input frequency of the signal generator, change the proportional coefficient of the power amplifier to adjust the magnitude of the primary input current, and measure multiple groups of load voltages, load resistors, and the output voltage of the Rogowski coil under different proportional coefficient conditions and find the average value. Among them, the average load voltage is the average load resistor is the average output voltage of the Rogowski coil is

[0073] According to the primary current calculation formula the average value of the actual primary current under different magnification conditions can be obtained: According to K = I in / V out the average value of the scale factor under different current conditions can be calculated:

[0074]

[0075] For the measured and perform linear fitting to obtain the relationship between the scale factor and the change of the current amplitude: and calculate the linearity δ of the fitting line. If δ is within 3‰, it indicates that the influence of the current amplitude change on the scale factor is small, and the method of extrapolating the scale factor under large current conditions using a small current generator is feasible;

[0076] S4. Frequency calibration of the Rogowski coil line scale factor:

[0077] Take the sine wave as the signal input, set the amplifier multiple to be fixed, change the sine wave input frequency at equal intervals, and measure the average value of the scale factor under different frequency conditions according to the similar method in S3. At the same time, according to and the corresponding f = [f1, f2, f3, f n are used for curve fitting to obtain the relationship between the scale factor and the change in current frequency:

[0078]

[0079] S5. Verification after calibration of the scale factor of the Rogowski coil:

[0080] By randomly changing the sine wave input frequency and measuring the actual current value I flowing through the Rogowski coil 总i and the voltage value output by the Rogowski coil Using the frequency of the input signal to substitute into the frequency fitting curve to solve for the theoretical scale factor K i = F(f i ), the measured current value is and calculate the relative error γ:

[0081]

[0082] If the measurement error of the Rogowski coil with a nominal accuracy of 1% after calibration is better than 5‰ under different frequency conditions, it meets the calibration requirements.

[0083] Among them, in step S1, to ensure that the current and voltage flowing through the load resistor are within the rated range, 25 60Ω high-power aluminum shell resistors are connected in parallel for the low-temperature drift precision resistor, and the total resistance value is controlled at 3Ω, and the maximum allowable current flowing through is 15A; the aluminum shell resistor itself has a heat dissipation effect, and at the same time, the parallel aluminum shell resistors are placed on a large-scale heat dissipation copper sheet to avoid excessive resistance temperature.

[0084] In step S2, the functional digital multimeter is an eight-and-a-half-digit high-precision digital multimeter; the high-precision data acquisition card is a 16-bit data acquisition card, which is used to reduce the error of the measuring instrument and ensure the accuracy of the mean voltage of the measured sine wave and the load resistor.

[0085] In step S2, the upper computer measurement software has functions such as waveform display, waveform spectrum analysis, amplitude measurement, and rise time measurement. When measuring a sine wave, the measured voltage peak value is converted into the voltage effective value for scale factor calculation.

[0086] In step S3, the current amplitude change range is between 50A and 500A, and the signal source input signal frequency is 100Hz; if the function linearity δ between the measured amplitude and the scale factor is better than 3‰, then the scale factors of the current amplitude changes under each frequency condition are averaged and used as the fixed scale factor; if the linearity is poor, then the influence of the amplitude change on the scale factor is fitted into a curve, and the error correction is performed on the frequency calibration curve of S4.

[0087] In step S4, according to the measurement characteristics of the Rogowski coil, the frequency change range during frequency calibration is 100 Hz to 10 KHz, and the equal-spacing interval is 50 Hz; to improve the calibration accuracy, the average value of the measured calibration data is 50 groups.

[0088] In steps S3 and S4, the influence of the current amplitude change on the scale factor can be used as a fixed error correction factor to correct the frequency model, and the correction method is as follows:

[0089] (3) Set the amplitude correction factor as Kv and fix the amplitude I f The function under the condition is The corresponding error correction function is

[0090] (4) Kv is calculated as follows:

[0091] ① If The linearity δ of is < 3‰, Kv = 1;

[0092] ② If The linearity δ of is > 3‰,

[0093] The specific calibration working process is as follows:

[0094] ① Build a Rogowski coil scale factor calibration test system and use an oscilloscope to test whether the output signal is distorted;

[0095] ② Set the frequency of the signal source and the amplification factor of the precision amplifier;

[0096] ③ The test system works stably for 30 min to ensure that the resistance value of the load resistor changes stably;

[0097] ④ Use a multifunctional digital multimeter to measure the load voltage multiple times and use the labview software program to collect the output voltage of the Rogowski coil multiple times;

[0098] ⑤ After a single test, power off and measure the load resistance value;

[0099] ⑥ Perform all amplitude and frequency values according to the same measurement steps;

[0100] ⑦ Fit the amplitude change curve and the frequency curve and verify the accuracy after calibration;

[0101] ⑧ If the accuracy after calibration meets the requirements, the calibration test ends.

[0102] Embodiment 2

[0103] A high-precision calibration device for a Rogowski coil used for measuring pulsed high currents, comprising:

[0104] A memory for storing programs;

[0105] A processor, which is configured to implement the steps of the high-precision calibration method for Rogowski coils used in pulse high-current source measurement described in Embodiment 1 when executing a program stored in a memory.

[0106] Embodiment 3

[0107] A storage medium, on which a computer program is stored, and the computer program is executed by a processor to implement the steps of the high-precision calibration method for Rogowski coils used in pulse high-current source measurement described in the embodiment.

[0108] As described above, the foregoing is only a specific implementation manner of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure can easily think of changes or substitutions, which should all be covered by the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A high-precision calibration method for Rogowski coils used in pulsed high-current source measurements, characterized in that, The steps are as follows: S1. Build an adjustable Class 100 precision current test source: A high-power precision current generating source is composed of a signal generator and a precision power amplifier. At the same time, a precision resistor with low temperature drift is used as the load resistor to build a precision current test source. The output channel of the signal generator is connected to the signal input interface of the precision power amplifier, and the output terminal of the precision power amplifier is connected in parallel with the load resistor array. By adjusting the signal type, amplitude, and the ratio of the precision power amplifier of the signal generator, the signal type, amplitude characteristics, and frequency characteristics of the current flowing through the load are changed, providing a test source for the linearity calibration and frequency calibration of the Rogowski coil; wind multiple turns of coil on the current loop and pass through the Rogowski coil to increase the maximum primary current flowing through the Rogowski coil to 500 A. The induced current of the Rogowski coil is as follows: Among them, I 总 is the total primary current flowing through the Rogowski coil; N is the number of turns of the coil; V is the voltage across the load resistor; R is the load resistor; The output amplitude can be obtained according to the factory calibration factor K: V = K·I 总 ; S2. Build a calibration test system for the Rogowski coil calibration factor: The calibration test system includes the Rogowski coil under test, a precision current test source of 100A class, a multifunctional digital multimeter, a high-precision data acquisition card, a host computer, and a collection and analysis software module. Among them, the probes of the multifunctional digital multimeter are respectively placed at both ends of the load resistor to measure the voltage and resistance at both ends of the load resistor of the current test source, and obtain the current flowing through the load resistor. The actual current flowing through the Rogowski coil can be calculated according to the number of turns of the coil. The high-precision data acquisition card, the host computer, and the collection and analysis software module form a Rogowski coil output voltage test unit to collect the output voltage amplitude in real time. According to the scale factor calculation formula: K = I in / V out the scale factor value can be calculated. Among them, I in is the primary current, and V out is the output voltage of the Rogowski coil. S3. Linearity calibration of the current amplitude of the Rogowski coil calibration factor: Set the input waveform and input frequency of the signal generator, change the proportionality coefficient of the power amplifier to adjust the magnitude of the primary input current, and measure multiple sets of load voltages, load resistances, and the output voltages of Rogowski coils under different proportionality coefficient conditions and calculate the mean values; among them, the mean value of the load voltage is The mean value of the load resistance is The mean value of the output voltage of the Rogowski coil is According to the original side current calculation formula The average value of the actual original side current under different magnification conditions can be obtained: According to K = I in / V out The average value of the scale factor under different current conditions can be calculated: For the measured and perform linear fitting to obtain the relationship between the scale factor and the change in current amplitude: And calculate the linearity δ of the fitting line. If δ is within 3‰, it indicates that the influence of the change in current amplitude on the scale factor is small, and the method of using a small current generator to extrapolate the scale factor under large current conditions is feasible; S4. Frequency calibration of the Rogowski coil calibration factor: Input a sine wave as the signal, set the amplifier magnification to be fixed, change the input frequency of the sine wave at equal intervals, and measure the mean value of the scale factor under different frequency conditions by a similar method in S3; meanwhile, according to and the corresponding f = [f1, f2, f3, … f n perform curve fitting to obtain the relationship between the scale factor and the change in current frequency: S5. Verification after calibration of the Rogowski coil calibration factor: By randomly changing the sine wave input frequency and measuring the actual current value I flowing through the Rogowski coil 总i and the voltage value output by the Rogowski coil Using the frequency of the input signal to substitute into the frequency fitting curve to solve the theoretical scale factor K i = F(f i ), the measured current value is and calculate the relative error γ: If the measurement error of the calibrated Rogowski coil with a nominal accuracy of 1% under different frequency conditions is better than 5‰, it meets the calibration requirements.

2. The high-precision calibration method for Rogowski coils used in pulsed high-current source measurement according to claim 1, characterized in that In step S1, to ensure that the current and voltage flowing through the load resistor are within the rated range, 25 60Ω high-power aluminum shell resistors are used in parallel for the precision resistor with low temperature drift, and the total resistance value is controlled at 3Ω, and the maximum allowable current flowing through is 15 A; the aluminum shell resistor itself has a heat dissipation effect, and at the same time, the parallel aluminum shell resistors are placed on a large-scale heat dissipation copper sheet to avoid excessive resistor temperature.

3. The high-precision calibration method of the Rogowski coil for pulsed high-current source measurement according to claim 1, characterized in that, In step S2, the multifunctional digital multimeter is an eight-and-a-half-digit high-precision digital multimeter; the high-precision data acquisition card is a 16-bit data acquisition card, which is used to reduce the error of the measuring instrument and ensure the accuracy of the mean voltage of the measured sine wave and the load resistor.

4. The high-precision calibration method of Rogowski coil for pulsed high-current source measurement according to claim 1, characterized in that, In step S2, the upper computer measurement software has functions of waveform display, waveform spectrum analysis, amplitude measurement, and rise time measurement. When measuring a sine wave, the measured voltage peak value is converted into the voltage effective value for calibration factor calculation.

5. The high-precision calibration method of Rogowski coil for pulsed high-current source measurement according to claim 1, characterized in that In step S3, the current amplitude change range is between 50 A and 500 A, and the signal source input signal frequency is 100 Hz; if the function linearity δ between the measured amplitude and the calibration factor is better than 3‰, the calibration factors of the current amplitude changes under each frequency condition are averaged and used as the fixed calibration factor; if the linearity is poor, the influence of the amplitude change on the calibration factor is fitted into a curve, and the error correction is performed on the frequency calibration curve of S4.

6. The high-precision calibration method of the Rogowski coil for pulsed high-current source measurement according to claim 1, characterized in that In step S4, according to the measurement characteristics of the Rogowski coil, the frequency change range during the frequency calibration process is 100 Hz to 10 KHz, and the equal-spacing interval is 50 Hz; to improve the calibration accuracy, the average value of the measured calibration data is 50 groups.

7. The high-precision calibration method for Rogowski coils used in pulsed high-current source measurements according to claim 1, characterized in that In steps S3 and S4, the influence of the current amplitude change on the calibration factor can be used as a fixed error correction factor to correct the frequency model. The correction method is as follows: (1) Set the amplitude correction factor as Kv and fix the amplitude I f The function under the condition is The corresponding error correction function is (2) Kv is calculated as follows: ① If the linearity δ < 3‰, Kv = 1; ② If the linearity δ of 8. The high-precision calibration method of Rogowski coil for pulsed high-current source measurement according to any one of claims 1-7, characterized in that The specific calibration working process is: ①Build a calibration test system for the Rogowski coil scale factor, and use an oscilloscope to test whether the output signal is distorted; ②Set the frequency of the signal source and the amplification factor of the precision amplifier; ③Test the system for stable operation for 30 minutes to ensure stable change in the load resistance value; ④Use a multi-functional digital multimeter to measure the load voltage multiple times, and use the LabVIEW software program to collect the output voltage of the Rogowski coil multiple times; ⑤After each single test, cut off the power supply and measure the load resistance value; ⑥Traverse all amplitude and frequency values according to the same measurement steps; ⑦Fit the amplitude change curve and the frequency curve, and verify the accuracy after calibration; ⑧If the accuracy after calibration meets the requirements, the calibration test ends.

9. A high-precision calibration device for Rogowski coils used in pulsed high-current source measurements, characterized in that, Including: A memory for storing programs; A processor for implementing the steps of the high-precision calibration method for the Rogowski coil used for pulsed high-current source measurement as described in any one of claims 1-8 when executing the program stored in the memory.

Images