Impulse current measurement method and system based on shunt

Abstract

The invention discloses a shunt-based impact current measurement method and system, and the method comprises the steps: carrying out the selection of a non-inductive shunt based on the amplitude, duration and system impedance of a target impact current, so as to determine a target shunt, and arranging the target shunt in a measured impact current loop; the voltage signals at the two ends of the target shunt are connected to a high-speed differential amplifier to obtain voltage amplification signals; collecting the voltage amplification signal to obtain collected data; carrying out band-pass filtering and de-noising processing on the acquired data, and reversely deducing a current original waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt; and performing temperature drift compensation on the current original waveform based on the system temperature measured in real time to obtain a current correction waveform. According to the invention, the problems of slow response, insufficient frequency bandwidth, measurement distortion, poor anti-interference capability and the like in the prior art are solved, and real-time and accurate measurement of large-amplitude and high-frequency impact current waveforms can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of current measurement, and more particularly, to a shunt-based impulse current measurement method and system. BACKGROUND

[0002] Impulse current is a transient large current signal with rapid rise and fall, which widely exists in power equipment failure, electromagnetic compatibility test and high-energy physics experiment. Due to the characteristics of short rise time (usually in the order of μs), high amplitude (up to kA or even higher) and extremely short duration, the traditional measurement method is difficult to accurately reflect the real waveform.

[0003] The existing impulse current measurement mainly uses current transformers, Hall sensors or Rogowski coils, but has the following defects: 1. The response speed is not fast enough: especially in the face of ns-μs level rise time, the traditional measurement device cannot respond in time. 2. Large non-linear error: under high current impulse, the magnetic material is easy to saturate, resulting in measurement distortion. 3. Difficult electrical isolation: the current path and the signal acquisition path are easy to couple and interfere with each other. 4. High cost and complex structure: some devices are bulky, which is not conducive to integration and portable application. In contrast, shunt, as a low resistance resistor, has the advantages of fast response, good linearity and low cost in transient large current measurement. If the shunt-based measurement method is designed reasonably, high-precision, high-bandwidth and high-stability impulse current measurement can be achieved without changing the existing test environment.

[0004] Therefore, there is a need for a shunt-based impulse current measurement method and system. SUMMARY

[0005] The present application proposes a shunt-based impulse current measurement method and system to solve the problem of how to efficiently and accurately determine the impulse current.

[0006] In order to solve the above problems, according to one aspect of the present application, a shunt-based impulse current measurement method is provided, which comprises:

[0007] Based on the amplitude, duration and system impedance of the target impulse current, the selection of the non-inductive shunt is performed to determine the target shunt, and the target shunt is set in the measured impulse current loop to form a series connection with the current path in the loop, so that the target impulse current flows through the target shunt;

[0008] The voltage signal across the target shunt is connected to a high-speed differential amplifier to obtain a voltage amplification signal;

[0009] The voltage amplification signal is collected to obtain collection data;

[0010] band-pass filtering and de-noising the collected data, and inversely deducing a current original waveform according to a gain of the high-speed differential amplifier and a resistance value of the target shunt;

[0011] temperature drift compensating the current original waveform based on a system temperature measured in real time to obtain a current corrected waveform.

[0012] Preferably, the high-speed differential amplifier is arranged in a metal shielding cavity, and a coaxial cable or a shielded twisted pair cable is used to transmit the signal.

[0013] Preferably, the method further comprises:

[0014] power isolation is achieved by using an isolation transformer installed at a power input end of the measurement system; and / or

[0015] signal conversion and isolated transmission are achieved by using an opto-isolator module connected to an output end of the high-speed differential amplifier.

[0016] Preferably, when collecting the voltage amplified signal, the method triggers signal collection based on an externally or internally set trigger source; the trigger source includes a current rising edge trigger, a threshold mutation trigger, and / or an adaptive sliding judgment algorithm trigger.

[0017] Preferably, inversely deducing the current original waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt includes:

[0018] I(t) = V(t) / R shunt G,

[0019] wherein I(t) is the current original waveform, V(t) is the collected voltage amplified signal, R is the resistance value of the target shunt, and G is the gain of the high-speed differential amplifier. shunt

[0020] Preferably, the method further comprises:

[0021] characteristic parameters in the current original waveform are extracted based on a frequency domain feature extraction method, and an impact type is determined based on the characteristic parameters; the characteristic parameters include a peak current, a rise time, a half-peak width, and a current integral value.

[0022] Preferably, temperature drift compensating the current original waveform based on a system temperature measured in real time to obtain a current corrected waveform includes:

[0023] I corr = I raw + a(T-T0) + b(T-T0) 2 ​+cI raw (T-T0),

[0024] wherein, I corr is the compensated current correction value; I raw is the original current measurement value; T is the real-time measured system temperature; T0 is the reference temperature; a, b are the temperature linear and quadratic compensation coefficients; c is the cross-coupling coefficient of current and temperature.

[0025] According to another aspect of the present application, there is provided a shunt-based impulse current measurement system, the system comprising:

[0026] a target shunt selection unit for selecting an inductive shunt based on the amplitude, duration of the target impulse current and the system impedance to determine the target shunt, and setting the target shunt in the measured impulse current loop to form a series connection with the current path in the loop, so that the target impulse current flows through the target shunt;

[0027] a voltage signal amplification unit for connecting the voltage signal across the target shunt to a high-speed differential amplifier to obtain a voltage amplified signal;

[0028] a signal acquisition unit for acquiring the voltage amplified signal to obtain acquisition data;

[0029] a current original waveform determination unit for band-pass filtering and denoising the acquisition data, and inversely deducing the current original waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt;

[0030] a correction unit for compensating the temperature drift of the current original waveform based on the real-time measured system temperature to obtain a current corrected waveform.

[0031] Preferably, the high-speed differential amplifier is arranged in a metal shielding cavity, and uses coaxial lines or shielded twisted pairs to transmit signals.

[0032] Preferably, the system further comprises:

[0033] an isolation transformer installed at the input end of the power supply of the measurement system to realize power supply isolation; and / or

[0034] an opto-isolator module connected to the output end of the high-speed differential amplifier to realize signal conversion and isolated transmission.

[0035] Preferably, the signal acquisition unit triggers the signal acquisition based on an externally or internally set trigger source when acquiring the voltage amplified signal; wherein the trigger source includes a current rising edge trigger, a threshold mutation trigger and / or an adaptive sliding judgment algorithm trigger.

[0036] Preferably, the current raw waveform determination unit determines the current raw waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt, comprising:

[0037] I(t) = V(t) / R shunt G,

[0038] wherein I(t) is the current raw waveform; V(t) is the collected voltage amplified signal; R shunt is the resistance value of the target shunt; G is the gain of the high-speed differential amplifier.

[0039] Preferably, the system further comprises:

[0040] An impact type determination unit is configured to extract a feature parameter in the current raw waveform based on a frequency domain feature extraction system, and determine the impact type based on the feature parameter; wherein the feature parameter comprises a peak current, a rise time, a half-peak width, and a current integral value.

[0041] Preferably, the correction unit performs temperature drift compensation on the current raw waveform based on a real-time measured system temperature to obtain a current corrected waveform, comprising:

[0042] I corr = I raw + a(T-T0) + b(T-T0) 2 +cI raw (T-T0),

[0043] wherein I corr is the compensated current corrected value; I raw is the current raw measured value; T is the real-time measured system temperature; T0 is the reference temperature; a and b are temperature linear and quadratic compensation coefficients; c is the cross-coupling coefficient of current and temperature.

[0044] The application provides a shunt-based impulse current measurement method and system, which comprises the following steps: selecting an inductive shunt based on the amplitude, duration and system impedance of a target impulse current, determining a target shunt, and setting the target shunt in a measured impulse current loop to form a series connection with the current path in the loop, so that the target impulse current flows through the target shunt; connecting the voltage signal between the two ends of the target shunt to a high-speed differential amplifier to obtain a voltage amplified signal; collecting the voltage amplified signal to obtain collected data; performing band-pass filtering and denoising processing on the collected data, and inversely deducing a current original waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt; and performing temperature drift compensation on the current original waveform based on the real-time measured system temperature to obtain a current corrected waveform. The application improves the shunt structure, electromagnetic compatibility design, signal acquisition link, trigger mechanism, data processing algorithm and self-adaptive calibration, realizes high-precision and high-stability measurement of high-amplitude and high-speed change impulse current signals, overcomes the problems of slow response, insufficient frequency bandwidth, measurement distortion and poor anti-interference ability in the prior art, and can realize real-time and accurate measurement of large-amplitude and high-frequency impulse current waveforms. BRIEF DESCRIPTION OF DRAWINGS

[0045] The exemplary embodiments of the present application can be more fully understood with reference to the following description when taken in connection with the accompanying drawings, in which:

[0046] Figure 1 A flowchart of a shunt-based impulse current measurement method 100 according to an embodiment of the present application;

[0047] Figure 2 A structural schematic diagram of a shunt-based impulse current measurement system 200 according to an embodiment of the present application. DETAILED DESCRIPTION

[0048] The exemplary embodiments of the present application will now be described with reference to the accompanying drawings. The present application can, however, be carried out in many different ways, and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art. The terminology used in the description of the exemplary embodiments presented herein is not intended to be limiting of the present application. Identical elements are denoted using identical reference numerals in the various figures.

[0049] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0050] Figure 1 A flow chart of the shunt-based impulse current measurement method 100 according to an embodiment of the present application. As shown, the shunt-based impulse current measurement method 100 provided by the embodiment of the present application starts from step 101, in which, based on the amplitude, duration and system impedance of the target impulse current, the selection of the non-inductive shunt is performed to determine the target shunt, and the target shunt is arranged in the measured impulse current circuit to form a series connection with the current path in the circuit, so that the target impulse current flows through the target shunt. Figure 1

[0051] In the present application, according to the amplitude (such as 1kA) and duration (usually 100μs) of the target impulse current and the system impedance, a non-inductive shunt with low inductance and high power carrying capacity is selected, such as a manganese copper band rolling type, a rectangular parallel reverse winding method and the like. The mounting structure can also be optimized to reduce the parasitic inductance (<50nH), and specifically, symmetrically leading ends and low-resistance soldering sheet connections are used to avoid measurement errors caused by waveform reflection or electromagnetic interference.

[0052] In step 102, the voltage signal across the target shunt is connected to a high-speed differential amplifier to obtain a voltage amplified signal.

[0053] Preferably, the high-speed differential amplifier is arranged in a metal shielding cavity, and coaxial lines or shielded twisted pairs are used to transmit signals.

[0054] Preferably, the method further comprises:

[0055] A power supply isolation is achieved by using an isolation transformer installed at the power input end of the measurement system; and / or

[0056] A signal conversion and isolated transmission are achieved by using an opto-isolator module connected to the output end of the high-speed differential amplifier.

[0057] In the present application, in terms of voltage acquisition and signal conditioning, the weak voltage signal across the shunt is connected to a high-speed differential amplifier, the input impedance of which is higher than 1MΩ, the bandwidth is not less than 100MHz, and the amplification factor is determined by the full-scale voltage of the sampling system. The differential amplifier is arranged in a metal shielding cavity, and coaxial lines or shielded twisted pairs are used to transmit signals to prevent external high-frequency interference coupling.

[0058] Optionally, an isolation transformer or an opto-isolator module can also be used to further suppress common-mode interference and improve system safety.

[0059] ​Specifically, the isolation transformer can cut off the common-mode interference path, avoid interference into the measurement circuit, realize high and low voltage isolation, and prevent high voltage from invading to protect equipment and personnel. Installed at the input end of the measurement system power supply, it provides power for the measurement circuit to realize power isolation.

[0060] The optoelectronic isolation module can isolate the electrical connection in signal transmission, avoid common-mode interference and ground potential difference, and resist electromagnetic interference to ensure stable signal transmission. It is installed on the signal path between the high-speed differential amplifier and the data acquisition unit to complete signal conversion and isolated transmission.

[0061] In step 103, the voltage amplification signal is collected to obtain collected data.

[0062] Preferably, in the method, when collecting the voltage amplification signal, the signal collection is triggered based on an externally or internally set trigger source; the trigger source includes current rising edge trigger, threshold mutation trigger, and / or adaptive sliding judgment algorithm trigger.

[0063] In the present application, in terms of data collection and intelligent triggering, the sampling rate of the collection system is ≥500MSa / s, with ≥12-bit precision, and the input channel matches the output impedance of the high-frequency amplifier, for example, a high-speed ADC card or a digital oscilloscope can be used for data collection. External or internal trigger sources are set, including (1) current rising edge trigger, (2) threshold mutation trigger, and (3) adaptive sliding judgment algorithm trigger, to ensure that the front edge, peak value, slow descent, and decay segment of the impact process can be completely collected.

[0064] In addition, ring buffer technology is used to retain a certain amount of "pre-event data" before triggering, which is used to analyze the system state before the impact.

[0065] In step 104, the collected data is subjected to band-pass filtering and denoising processing, and the current original waveform is inversely deduced according to the gain of the high-speed differential amplifier and the resistance value of the target shunt.

[0066] Preferably, inversely deducing the current original waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt includes:

[0067] I(t) = V(t) / R shunt G,

[0068] where I(t) is the current original waveform, V(t) is the collected voltage amplification signal, R is the resistance value of the target shunt, and G is the gain of the high-speed differential amplifier. shunt

[0069] Preferably, the method further comprises:

[0070] ​The characteristic parameters in the current original waveform are extracted based on a frequency domain characteristic extraction method, and the impact type is determined based on the characteristic parameters; wherein the characteristic parameters include: peak current, rise time, half-peak width and current integral value.

[0071] In the application, the collected data is band-pass filtered and denoised to filter out high-frequency noise and low-frequency drift in data processing and waveform reconstruction; and then the current original waveform I(t)=V(t) / R is inversely deduced according to the amplifier gain and the shunt resistor value shunt G; wherein I(t) is the current original waveform; V(t) is the collected voltage amplified signal; R shunt is the resistor value of the target shunt; and G is the gain of the high-speed differential amplifier.

[0072] In the application, the characteristic parameters such as peak current, rise time, half-peak width, current integral value (equivalent charge amount) can also be extracted for analysis of the impact current type. Specifically, the characteristic parameters are extracted based on a frequency domain characteristic extraction method such as FFT or STFT, and the impact type is determined. The neural network can be expanded to classify the mode. The type can be lightning / switching arc / EMI, etc.

[0073] In step 105, the current original waveform is compensated for temperature drift based on the real-time measured system temperature to obtain a current corrected waveform.

[0074] Preferably, wherein the current original waveform is compensated for temperature drift based on the real-time measured system temperature to obtain a current corrected waveform, comprising:

[0075] I corr =I raw +a(T-T0)+b(T-T0) 2 +cI raw (T-T0),

[0076] wherein I corr is the compensated current correction value; I raw is the current original measurement value; T is the real-time measured system temperature; T0 is the reference temperature; a and b are temperature linear and quadratic compensation coefficients; and c is the cross-coupling coefficient of current and temperature.

[0077] In the application, calibration is performed in the initial stage of the system: multi-point calibration (error compensation values at different temperatures) is performed using a standard pulse current source, and the response offset is recorded; the system temperature is measured in real time (such as using a thermistor / integrated temperature sensor), and temperature drift compensation is performed in combination with a calibration table. A software compensation model can be optionally used to perform quadratic fitting on the nonlinear region, further improving the accuracy in the high-amplitude impact interval.

[0078] Wherein, the quadratic fitting formula can adopt:

[0079] I corr =I raw +a(T-T0)+b(T-T0) 2 +cI raw (T-T0)

[0080] I corr is the compensated current correction value; I raw is the original current measurement value; T is the real-time measured system temperature; T0 is the reference temperature (usually 25 DEG C) ; a, b are temperature linear and quadratic compensation coefficients (obtained by fitting the calibration data at different temperatures) ; c is the cross-coupling coefficient of current and temperature (used to correct the non-linear correlation error of temperature and current under high amplitude impact).

[0081] In the present application, the extracted characteristic parameters of the impulse current and the original current waveform and the current correction waveform are finally displayed in a graphical and numerical manner, and CSV / TDMS / image formats are supported. All test information can also be time-stamped and saved to the local or server, and supported to be connected with the database and test system to form a traceable archive.

[0082] The impulse current measurement method based on the shunt provided by the present application realizes high-precision and high-stability measurement of high-amplitude and high-speed changing impulse current signals through technical innovations in six aspects of shunt structure, electromagnetic compatibility design, signal acquisition link, triggering mechanism, data processing algorithm and adaptive calibration strategy, and overcomes the problems of slow response, insufficient frequency bandwidth, measurement distortion and poor anti-interference ability existing in the prior art. Specifically, it includes:

[0083] (1) By adopting a low-inductance non-inductive shunt (equivalent inductance < 50nH) in combination with a differential amplifier with a bandwidth exceeding 100MHz, the impulse current response capture capability of nanosecond level is realized, and the current waveform with a rise time of less than 100ns can be accurately measured, which is a major breakthrough in time resolution over the traditional method.

[0084] (2) The method adopts a differential sampling scheme with high common-mode rejection ratio and a complete EMC design (including shielding, isolation, anti-vibration layout, etc.), which significantly improves the suppression capability of the system to common-mode interference, electromagnetic interference (EMI) and power frequency coupling interference, so that the system can still operate stably and maintain high-precision output in a high-voltage and high-interference field environment.

[0085] (3) Unlike the traditional fixed resistance value shunt system, the present application proposes a multi-shunt parallel structure + adaptive conditioning circuit, which supports accurate measurement of impulse currents from 10A to 10kA or even higher, and has excellent dynamic range adaptation capability.

[0086] (4) First introduced in the type of measurement system "adaptive trigger judgment logic" and "pre-cached area mechanism", can be saved before the impact of the event occurred effective waveform segment, with the post-processing algorithm to achieve complete, no gap waveform reconstruction, effectively prevent the loss of key event data.

[0087] (5) Combined with feature extraction algorithm (such as FFT, wavelet, envelope analysis) and optional neural network model, the system can quickly classify the collected shock waveform type (such as lightning, electrostatic discharge, arc discharge, etc.), improve the automation processing ability of test data, and promote the measurement equipment from "recording type" to "intelligent identification type".

[0088] (6) Considering that the impulse current test equipment is prone to error in different temperature environments, the method has a temperature monitoring unit and combines with a multi-point calibration curve to use a dynamic correction algorithm to compensate for the resistance drift of the shunt and the signal amplification drift in real time, ensuring consistency and reliability under long-term operating conditions.

[0089] The following specific examples illustrate the embodiments of the present application

[0090] In the embodiments of the present application, the method of the present application is applied in lightning simulation test of electrical equipment, and the target is to accurately measure the lightning waveform (8 / 20 μs) impulse current, the peak value of which can reach 1000 A, and it is widely used in lightning resistance verification of lightning arresters, cable joints, electrical cabinets and other components.

[0091] Among them, in terms of shunt configuration: the inductive manganese copper strip shunt with a resistance value of 0.1 mΩ is selected, the rated peak current is 10 kA, and the bandwidth test reaches 200 MHz; it is installed in the discharge circuit and connected with the conductor by a multi-point bolt crimping method to ensure low contact resistance.

[0092] Among them, in terms of signal conditioning: the shielded twisted pair wire is used for the lead wire at both ends of the shunt, the THS4521 high-speed differential amplifier module of TI company is connected, and the gain is set to 20 times; the amplifier is installed in a metal shielding box, and the power supply and signal path are both designed to be isolated.

[0093] Among them, in terms of data acquisition and triggering: a digital oscilloscope with a sampling rate of 1 GS / s and a bandwidth of 300 MHz is used; the trigger voltage threshold is set to 10 mV (corresponding to 100 A of impulse current), and the "pre-trigger" function is started to ensure that the complete waveform before and after is captured.

[0094] Among them, in terms of waveform processing and parameter extraction: the built-in algorithm is used to filter out sharp interference pulses; the current value is calculated according to the voltage / resistance / gain, and the peak value, rise time, duration, charge quantity and other parameters are extracted.

[0095] Among them, in terms of result and error correction: automatically correct the temperature drift by software under the condition of ambient temperature 40℃; compared with the traditional Hall current probe, the measurement result error is reduced from ±12% to ±3%.

[0096] Figure 2 A schematic diagram of the structure of the shunt-based impulse current measurement system 200 according to the embodiment of the present application. As shown in the figure, the shunt-based impulse current measurement system 200 provided by the embodiment of the present application comprises a target shunt selection unit 201, a voltage signal amplification unit 202, a signal acquisition unit 203, a current original waveform determination unit 204 and a correction unit 205. Figure 2

[0097] Preferably, the target shunt selection unit 201 is configured to select an inductive shunt based on the amplitude, duration and system impedance of the target impulse current, to determine the target shunt, and to set the target shunt in the measured impulse current loop, so that it is connected in series with the current path in the loop, so that the target impulse current flows through the target shunt.

[0098] Preferably, the voltage signal amplification unit 202 is configured to input the voltage signal across the target shunt into a high-speed differential amplifier to obtain a voltage amplified signal.

[0099] Preferably, the high-speed differential amplifier is arranged in a metal shielding cavity and uses coaxial lines or shielded twisted pairs to transmit signals.

[0100] Preferably, the system further comprises:

[0101] an isolation transformer installed at the input end of the power supply of the measurement system, for realizing power supply isolation; and / or

[0102] an opto-isolator module connected to the output end of the high-speed differential amplifier, for realizing signal conversion and isolated transmission.

[0103] Preferably, the signal acquisition unit 203 acquires the voltage amplified signal to obtain acquisition data.

[0104] Preferably, the signal acquisition unit 203 triggers signal acquisition based on an externally or internally set trigger source when acquiring the voltage amplified signal; wherein the trigger source comprises a current rising edge trigger, a threshold mutation trigger and / or an adaptive sliding judgment algorithm trigger.

[0105] Preferably, the current original waveform determination unit 204 is configured to perform band-pass filtering and de-noising processing on the acquisition data, and to inversely deduce the current original waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt.​

[0106] Preferably, the current raw waveform determination unit 204 determines the current raw waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt, comprising:

[0107] I(t) = V(t) / R shunt G,

[0108] wherein I(t) is the current raw waveform; V(t) is the collected voltage amplified signal; R shunt is the resistance value of the target shunt; G is the gain of the high-speed differential amplifier.

[0109] Preferably, the system further comprises:

[0110] a shock type determination unit for extracting a feature parameter in the current raw waveform based on a frequency domain feature extraction system, and determining a shock type based on the feature parameter; wherein the feature parameter comprises a peak current, a rise time, a half-peak width and a current integral value.

[0111] Preferably, the correction unit 205 performs temperature drift compensation on the current raw waveform based on a real-time measured system temperature to obtain a current corrected waveform.

[0112] Preferably, the correction unit 205 performs temperature drift compensation on the current raw waveform based on a real-time measured system temperature to obtain a current corrected waveform, comprising:

[0113] I corr = I raw + a(T-T0) + b(T-T0) 2 + cI raw (T-T0),

[0114] wherein I corr is the compensated current correction value; I raw is the current raw measurement value; T is the real-time measured system temperature; T0 is the reference temperature; a and b are temperature linear and quadratic compensation coefficients; c is the cross-coupling coefficient of current and temperature.

[0115] The shunt-based shock current measurement system 200 of the embodiment of the application corresponds to the shunt-based shock current measurement method 100 of another embodiment of the application, which will not be described here.

[0116] The application has been described by referring to a few embodiments. However, it is well known to those skilled in the art that other embodiments, etc. within the scope of the application are equivalent to the above disclosed embodiments of the application.

[0117] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined herein otherwise. All references to "a" or "an" means "at least one", unless otherwise specified by the context. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

[0118] Those skilled in the art will appreciate that embodiments of the present application can be devised for a method, a system, or a computer program product. Accordingly, the present application can be embodied in the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code.

[0119] The present application is described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processing system or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0120] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0121] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0122] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or equivalently replaced without departing from the spirit and scope of the present application, and any modification or equivalent replacement should be covered within the protection scope of the present application.

Claims

1. A shunt-based method of measuring surge current, characterized by, The method comprises: Based on the amplitude, duration and system impedance of the target impulse current, the selection of the non-inductive shunt is carried out to determine the target shunt, and the target shunt is arranged in the measured impulse current loop to form a series connection with the current path in the loop, so that the target impulse current flows through the target shunt; The voltage signal across the target shunt is connected to a high-speed differential amplifier to obtain a voltage amplified signal; The voltage amplified signal is collected to obtain collected data; The collected data is band-pass filtered and denoised, and the current original waveform is inversely deduced according to the gain of the high-speed differential amplifier and the resistance value of the target shunt; The current original waveform is compensated for temperature drift based on the real-time measured system temperature to obtain a current corrected waveform.

2. The method of claim 1, wherein, The high-speed differential amplifier is arranged in a metal shielding cavity and uses coaxial lines or shielded twisted pairs to transmit signals.

3. The method of claim 1, wherein, The method further comprises: The power supply is isolated by using an isolation transformer installed at the input end of the measurement system power supply; and / or Signal conversion and isolated transmission are realized by using an optoelectronic isolation module connected to the output end of the high-speed differential amplifier.

4. The method of claim 1, wherein, When collecting the voltage amplified signal, the signal collection is triggered based on an externally or internally arranged trigger source; wherein the trigger source comprises a current rising edge trigger, a threshold mutation trigger and / or an adaptive sliding judgment algorithm trigger.

5. The method of claim 1, wherein, The current original waveform is inversely deduced according to the gain of the high-speed differential amplifier and the resistance value of the target shunt, which comprises: I(t) = V(t) / R shunt G, Wherein, I(t) is the current original waveform; V(t) is the collected voltage amplification signal; R shunt is the resistance value of the target shunt; G is the gain of the high-speed differential amplifier.

6. The method of claim 1, wherein, The method further comprises: Characteristic parameters in the current original waveform are extracted based on a frequency domain feature extraction method, and the impulse type is determined based on the characteristic parameters; wherein the characteristic parameters comprise peak current, rise time, half-peak width and current integral value.

7. The method of claim 1, wherein, The current original waveform is compensated for temperature drift based on the real-time measured system temperature to obtain a current corrected waveform, which comprises: I corr = I raw + a(T - T0) + b(T - T0) 2 + cI raw (T - T0), wherein I corr is the compensated current correction value; I raw is the original current measurement value; T is the real-time measured system temperature; T0 is the reference temperature; a, b are the temperature linear and quadratic compensation coefficients; c is the cross-coupling coefficient of current and temperature.

8. A shunt-based impulse current measurement system, characterized by, The system comprises: A target shunt selection unit is configured to select a non-inductive shunt based on the amplitude, duration and system impedance of the target impulse current to determine a target shunt, and arrange the target shunt in a measured impulse current loop to form a series connection with a current path in the loop, so that the target impulse current flows through the target shunt; A voltage signal amplification unit is configured to connect a voltage signal across the target shunt to a high-speed differential amplifier to obtain a voltage amplified signal; A signal collection unit is configured to collect the voltage amplified signal to obtain collected data; A current original waveform determination unit is configured to band-pass filter and denoise the collected data, and inversely deduce a current original waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt; A correction unit is configured to compensate the current original waveform for temperature drift based on a real-time measured system temperature to obtain a current corrected waveform.

9. The system of claim 8, wherein, The high-speed differential amplifier is arranged in a metal shielding cavity and uses coaxial lines or shielded twisted pairs to transmit signals.

10. The system of claim 8, wherein, The system further comprises: An isolation transformer is installed at the input end of the measurement system power supply to achieve power supply isolation; and / or An optoelectronic isolation module is connected to the output end of the high-speed differential amplifier to achieve signal conversion and isolated transmission.

11. The system of claim 8, wherein, The signal acquisition unit triggers signal acquisition based on an externally or internally set trigger source when collecting the voltage amplification signal; wherein the trigger source includes a current rising edge trigger, a threshold mutation trigger, and / or an adaptive sliding judgment algorithm trigger.

12. The system of claim 8, wherein, The current original waveform determination unit inversely deduces the current original waveform according to the gain of the high-speed differential amplifier and the resistance value of the target shunt, including: I(t) = V(t) / R shunt G, Wherein, I(t) is the current original waveform; V(t) is the collected voltage amplification signal; R shunt is the resistance value of the target shunt; G is the gain of the high-speed differential amplifier.

13. The system of claim 8, wherein, The system further includes: An impact type determination unit is configured to extract a characteristic parameter in the current original waveform based on a frequency domain feature extraction system, and determine the impact type based on the characteristic parameter; wherein the characteristic parameter includes a peak current, a rise time, a half-peak width, and a current integral value.

14. The system of claim 8, wherein, The correction unit performs temperature drift compensation on the current original waveform based on a real-time measured system temperature to obtain a current corrected waveform, including: I corr = I raw + a(T - T0) + b(T - T0) 2 + cI raw (T - T0), wherein I corr is the compensated current correction value; I raw is the original current measurement value; T is the real-time measured system temperature; T0 is the reference temperature; a, b are the temperature linear and quadratic compensation coefficients; c is the cross-coupling coefficient of current and temperature.

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