A method and system for measuring charge quantity integration by loop noise cancellation

Abstract

The application discloses a method and system for measuring charge quantity integration by a loop noise elimination method. The method comprises the following steps: judging whether the time constant RCO of a circuit is less than the pulse rising time t r ; if the time constant RCO is less than the pulse rising time t r , measuring the charge quantity integration by the loop noise elimination method, and eliminating the random influence of the non-smoothness of the pulse voltage waveform by using a moving average; and if the time constant RCO is not less than the pulse rising time t r , exiting the measurement of the charge quantity integration.

Description

Technical Field

[0001] The present application relates to a method and system for measuring charge integral by loop noise elimination method, and in particular to a method and system for measuring charge integral by loop noise elimination method. Background Art

[0002] The object to be measured by the pulse current method partial discharge tester is the amplitude of the near-zero frequency spectrum line in the partial discharge signal band. Its working principle is to filter out a lower frequency segment from a signal with a bandwidth of several MHz. The frequency domain representation of the partial discharge pulse is: The charge is By measuring the signal amplitude, comparing and calculating the measured signal amplitude with the self-calibration signal amplitude, the amount of charge on the local discharge tube is determined.

[0003] A pulse current partial discharge tester includes accessories such as a detection impedance and a calibration pulse generator, which are required for partial discharge measurements. While a partial discharge tester measures the apparent charge in the circuit, not the actual charge, the calibration pulse generator outputs the actual charge, which is used to calibrate the partial discharge measurement circuit. Therefore, the accuracy of the charge output by the calibration pulse generator is crucial to the accuracy of the partial discharge tester's measurement results.

[0004] There are two traditional approaches to measuring the actual charge of a calibration pulse generator: one is to perform overall calibration based on the definition of charge as the integral of current over time; the other is to perform separate calibration of two components, the step voltage and the scaled capacitor, based on the equation q = UC. Accurately measuring the charge output by the calibration pulse generator is a key issue that needs to be addressed. Summary of the Invention

[0005] The embodiments of the present disclosure provide a method and system for measuring charge integral by loop noise elimination method, so as to at least solve the technical problem existing in the prior art of how to accurately measure the charge output by a calibration pulse generator.

[0006] According to one aspect of an embodiment of the present disclosure, a method for measuring charge integral by loop noise elimination is provided, comprising: determining whether the time constant RC0 of the circuit is less than the pulse rise time t r ; If RC0 is less than the pulse rise time t r , the charge integral is measured by the loop noise elimination method, and the moving average is used to eliminate the random influence of the non-smooth pulse voltage waveform; if RC0 is not less than the pulse rise time t r , exit the charge measurement integration.

[0007] According to another aspect of the present disclosure, a system for measuring charge integral by loop noise elimination method is provided, comprising: a judgment module for judging whether the time constant RC0 of the circuit is less than the pulse rise time t r ; Charge measurement module, used if RC0 is less than the pulse rise time t r , measure the charge integral by loop noise elimination method, and use moving average to eliminate the random influence of the non-smooth pulse voltage waveform; exit the measurement module, used to if RC0 is not less than the pulse rise time t r , exit the charge measurement integration.

[0008] The present invention utilizes a charge integration measurement technique based on a loop noise elimination method. Prior to charge integration measurement, a moving average of the pulse voltage is performed to reduce the impact of random errors, resulting in a smoother pulse waveform. The stored noise voltage waveform is on the same time scale as the measured pulse voltage waveform. The noise voltage waveform is subtracted from the pulse voltage waveform before integration, eliminating or reducing the impact of systematic errors introduced by various noise elements.

[0009] Based on the definition of charge, this paper optimizes the integral measurement technique for the actual charge output by the "calibration pulse generator" used to calibrate the partial discharge measurement circuit, achieving highly accurate measurement of the calibration pulse generator's charge. This addresses the problem of inaccurate measurement of the measured signal caused by noise generated by the numerous influencing variables and complex coupling mechanisms of distributed parameters in the measurement circuit. The ultimate goal of achieving accurate measurement of the calibration pulse generator's charge is to accurately calibrate the partial discharge measurement circuit, thereby ensuring accurate and reliable measurement data from the partial discharge instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of this application. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings:

[0011] Figure 1 1 is a flow chart for implementing a method for measuring charge integral by loop noise elimination according to an embodiment of the present disclosure;

[0012] Figure 2 2 is a schematic diagram of a system for measuring charge integral by loop noise elimination method according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0013] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a thorough and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments shown in the accompanying drawings is not intended to limit the present invention. In the accompanying drawings, identical elements are denoted by the same reference numerals.

[0014] Unless otherwise specified, the terms used herein (including technical terms) have the meanings commonly understood by those skilled in the art. In addition, it is understood that terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0015] According to a first aspect of the present application, a method 100 for measuring charge integral by loop noise elimination is provided. Figure 1 As shown, the method 100 includes:

[0016] Determine whether the circuit's time constant RC0 is less than the pulse rise time t r ;

[0017] If RC0 is less than the pulse rise time t r , the charge integral is measured by loop noise elimination method, and the moving average is used to eliminate the random influence of the uneven pulse voltage waveform;

[0018] If RC0 is not less than the pulse rise time t r , exit the charge measurement integration.

[0019] Specifically, (1) before measuring the charge integral, the pulse voltage should be moved and averaged to reduce the influence of random errors and make the pulse waveform smoother.

[0020] Since calibration under low charge is sensitive to the effects of grounding, shielding, and distributed parameters, it is necessary to eliminate the noise introduced by these factors. The following measures are mainly used to deal with loop noise. First, determine whether RC0 is less than the pulse rise time t r If the condition is satisfied, the charge integration measurement can be carried out by loop noise elimination method. In order to solve the problem that the pulse voltage waveform is not smooth and has a certain randomness, the moving average is used to eliminate the randomness.

[0021]

[0022] Right now

[0023]

[0024] u(t)——pulse voltage waveform data;

[0025] U t (t)——Pulse voltage waveform data after moving average processing;

[0026] N——Number of mobile evaluation items

[0027] The effective use of moving averages relies on the proper selection of sampling points and the number of averaged items. Regarding the number of points used, since the pulse rise time is specified as no more than 60ns in many partial discharge standards, the analog bandwidth of the oscilloscope-type instrument used to measure the pulse should be no less than 100MHz. The collected pulse waveform should be complete and have sufficient time domain resolution to enable the use of appropriate data processing algorithms to reduce the impact of random errors. The moving average described in the present invention is one of the commonly used algorithms. Data processing algorithms that can achieve the purpose of reducing random errors include, but are not limited to, the moving average algorithm described in the present invention. In the single-stage moving average algorithm described in the present invention, the greater the number of averaged items N, the stronger the smoothing effect of the moving average. Therefore, if the impact of irregular changes in the time series is significant, N should be larger to obtain a robust prediction value; conversely, if the impact of irregular changes is smaller, N should be smaller to ensure that the prediction value tracks and responds more quickly to changes in the phenomenon.

[0028] (2) The stored noise voltage waveform has the same time scale as the measured pulse voltage waveform;

[0029] In order to achieve effective elimination of the noise voltage by the measured voltage, since the present invention uses an oscilloscope-type instrument, it is required that the noise voltage waveform and the measured pulse voltage waveform have the same time scale. The implementation method is: connect the calibration pulse generator and the oscilloscope-type instrument, turn on the pulse generator charge output switch, and adjust the appropriate charge size, polarity, repetition rate and other parameters. Use the oscilloscope-type instrument to collect a complete pulse voltage waveform, and the waveform has appropriate horizontal and vertical scales. While keeping the scale position unchanged, turn off the pulse generator charge output switch. At this time, the oscilloscope-type instrument displays the noise of the measurement circuit, and stores the noise signal U noise .

[0030] (3) Subtract the noise voltage waveform from the pulse voltage waveform and then integrate it to eliminate the influence of system errors introduced by each noise element.

[0031] According to the definition of charge, charge is the integral of current over time. The noise voltage waveform should be subtracted from the pulse voltage waveform before integration to eliminate the systematic error introduced by each noise element.

[0032]

[0033] q – charge;

[0034] i(t) – current pulse generated by the calibrator;

[0035] R——standard resistance;

[0036] U t (t)——Pulse voltage waveform data after moving average processing;

[0037] U noise ——Noise voltage of the calibration loop.

[0038] A standard resistor is used to convert pulse current into pulse voltage, allowing oscilloscopes to accurately measure the voltage. The value of this standard resistor should be chosen to minimize resistance-induced pulse waveform oscillations. Furthermore, the resistor should not be too large, as this will result in a longer pulse decay time and amplify integration errors.

[0039] Therefore, a charge integration measurement technique based on a loop noise elimination method is proposed. Before measuring the charge integration, the pulse voltage is first moved and averaged to reduce the influence of random errors, making the pulse waveform smoother. The stored noise voltage waveform has the same time scale as the measured pulse voltage waveform. The noise voltage waveform is subtracted from the pulse voltage waveform before integration, thereby eliminating or reducing the influence of systematic errors introduced by various noise elements.

[0040] Based on the definition of charge, this paper optimizes the integral measurement technique for the actual charge output by the "calibration pulse generator" used to calibrate the partial discharge measurement circuit, achieving highly accurate measurement of the calibration pulse generator's charge. This addresses the problem of inaccurate measurement of the measured signal caused by noise generated by the numerous influencing variables and complex coupling mechanisms of distributed parameters in the measurement circuit. The ultimate goal of achieving accurate measurement of the calibration pulse generator's charge is to accurately calibrate the partial discharge measurement circuit, thereby ensuring accurate and reliable measurement data from the partial discharge instrument.

[0041] Optionally, using a moving average to eliminate the random influence of the non-smooth pulse voltage waveform includes: using a moving average to eliminate the random influence of the non-smooth pulse voltage waveform according to the following formula:

[0042]

[0043] Among them, u t is the pulse voltage waveform data, U t is the pulse voltage waveform data after moving average processing, and N is the number of moving evaluation items.

[0044] Alternatively, if RC0 is less than the pulse rise time t r, measuring the charge integral by loop noise elimination method, including: determining that the time scale of the noise voltage waveform is the same as the time scale of the measured pulse voltage waveform.

[0045] Alternatively, if RC0 is less than the pulse rise time t r , measuring the charge integral by the loop noise elimination method, further comprising: connecting a calibration pulse generator and an oscilloscope-type instrument; adjusting charge parameters, the charge parameters including charge magnitude, polarity, and repetition rate; using the oscilloscope-type instrument to collect a pulse voltage waveform, and determining that the pulse voltage waveform has a certain horizontal scale and vertical scale; while keeping the horizontal scale and vertical scale positions unchanged, turning off the charge output switch of the pulse generator, and storing the noise voltage waveform signal U of the measurement loop displayed by the oscilloscope-type instrument. noise .

[0046] Alternatively, if RC0 is less than the pulse rise time t r , measuring the charge integral by the loop noise elimination method, and also including: determining the pulse voltage waveform data Ut after moving average processing and the noise voltage waveform signal U noise According to the following formula, the difference is integrated to eliminate the systematic error introduced by the noise element:

[0047]

[0048] Where q is the charge, i(t) is the current pulse generated by the calibrator, R is the standard resistance, and U t (t)——pulse voltage waveform data after moving average processing, U noise is the noise voltage waveform signal.

[0049] According to another aspect of the present application, a system 200 for measuring charge integral by loop noise elimination is also provided. Figure 2 As shown, the system 200 includes: a judgment module 210, which is used to judge whether the time constant RC0 of the circuit is less than the pulse rise time t r ; Measuring charge module 220, for if RC0 is less than the pulse rise time t r , measure the charge integral by loop noise elimination method, and use moving average to eliminate the random influence of the non-smooth pulse voltage waveform; exit the measurement module 230, for if RC0 is not less than the pulse rise time t r , exit the charge measurement integration.

[0050] Optionally, the charge measurement module 220 includes a randomness elimination submodule configured to eliminate the randomness of the uneven pulse voltage waveform by using a moving average according to the following formula:

[0051]

[0052] Among them, u t is the pulse voltage waveform data, U t is the pulse voltage waveform data after moving average processing, and N is the number of moving evaluation items.

[0053] Optionally, the charge measurement module 220 includes: a time scale determination submodule, configured to determine whether the time scale of the noise voltage waveform is the same as the time scale of the measured pulse voltage waveform.

[0054] Optionally, the charge measurement module 220 further includes: a connection submodule for connecting a calibration pulse generator and an oscilloscope-type instrument; a parameter adjustment submodule for adjusting charge parameters, wherein the charge parameters include charge size, polarity, and repetition rate; a scale determination submodule for collecting a pulse voltage waveform using an oscilloscope-type instrument and determining that the pulse voltage waveform has a certain horizontal scale and vertical scale; and a noise voltage waveform storage submodule for turning off the pulse generator charge output switch while keeping the horizontal scale and vertical scale positions unchanged, and storing the noise voltage waveform signal U of the measurement circuit displayed by the oscilloscope-type instrument. noise .

[0055] Optionally, the charge measurement module 220 further includes a difference determination submodule for determining the difference between the pulse voltage waveform data Ut after moving average processing and the noise voltage waveform signal Ut. noise The system error submodule is used to integrate the difference according to the following formula to eliminate the system error introduced by the noise element:

[0056]

[0057] Where q is the charge, i(t) is the current pulse generated by the calibrator, R is the standard resistance, and U t (t)——pulse voltage waveform data after moving average processing, U noise is the noise voltage waveform signal.

[0058] A system 200 for measuring charge integral by loop noise elimination method according to an embodiment of the present invention corresponds to a method 100 for measuring charge integral by loop noise elimination method according to another embodiment of the present invention, and will not be described in detail here.

[0059] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal translation scripting language JavaScript, etc.

[0060] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0061] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0062] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0063] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0064] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for measuring charge integral by loop noise elimination, characterized in that: include: Determine whether the circuit's time constant RC0 is less than the pulse rise time t r ; If RC0 is less than the pulse rise time t r , the charge integral is measured by loop noise elimination method, and the moving average is used to eliminate the random influence of the uneven pulse voltage waveform; If RC0 is not less than the pulse rise time t r , exit the charge measurement integration; If RC0 is less than the pulse rise time tr, the charge integral is measured by loop noise elimination, which also includes: Determine the difference between the pulse voltage waveform data Ut after moving average processing and the noise voltage waveform signal Unoise; The difference is integrated according to the following formula to eliminate the systematic error introduced by the noise element: Where q is the charge, i(t) is the current pulse generated by the calibrator, R is the standard resistance, and U t (t) is the pulse voltage waveform data after moving average processing, and Unoise is the noise voltage waveform signal.

2. The method according to claim 1, characterized in that The moving average is used to eliminate the random influence of the uneven pulse voltage waveform, including: According to the following formula, moving average is used to eliminate the random influence of the non-smooth pulse voltage waveform: Among them, u t is the pulse voltage waveform data, U t is the pulse voltage waveform data after moving average processing, and N is the number of moving evaluation items.

3. The method according to claim 1, characterized in that If RC0 is less than the pulse rise time t r , the charge integral is measured by loop noise elimination, including: Make sure the time scale of the noise voltage waveform is the same as the time scale of the pulse voltage waveform being measured.

4. The method according to claim 3, characterized in that If RC0 is less than the pulse rise time t r , measuring the charge integral by loop noise elimination, also includes: Connect calibration pulse generators and oscilloscope-type instruments; Adjusting charge parameters, including charge magnitude, polarity, and repetition rate; Using an oscilloscope to collect a pulse voltage waveform, and determining that the pulse voltage waveform has a certain horizontal scale and vertical scale; While keeping the horizontal and vertical scale positions unchanged, turn off the pulse generator charge output switch and store the noise voltage waveform signal U of the measurement circuit displayed by the oscilloscope. noise .

5. A system for measuring charge integral by loop noise elimination, characterized in that: include: The judgment module is used to judge whether the circuit time constant RC0 is less than the pulse rise time t r ; Charge measurement module, used if RC0 is less than the pulse rise time t r , the charge integral is measured by loop noise elimination method, and the moving average is used to eliminate the random influence of the uneven pulse voltage waveform; Exit the measurement module if RC0 is not less than the pulse rise time t r , exit the charge measurement integration; The charge measurement module also includes: Determine the difference submodule, which is used to determine the difference between the pulse voltage waveform data Ut after moving average processing and the noise voltage waveform signal U noise The difference between The system error submodule is used to integrate the difference according to the following formula to eliminate the system error introduced by the noise element: Where q is the charge, i(t) is the current pulse generated by the calibrator, R is the standard resistance, and U t (t) is the pulse voltage waveform data after moving average processing, U noise is the noise voltage waveform signal.

6. The system according to claim 5, characterized in that Charge measurement module, including: The random influence elimination submodule is used to eliminate the random influence of the uneven pulse voltage waveform by using moving average according to the following formula: Among them, u t is the pulse voltage waveform data, U t is the pulse voltage waveform data after moving average processing, and N is the number of moving evaluation items.

7. The system according to claim 5, characterized in that Charge measurement module, including: The time scale determination submodule is used to determine whether the time scale of the noise voltage waveform is the same as the time scale of the measured pulse voltage waveform.

8. The system according to claim 7, characterized in that The charge measurement module also includes: Connecting submodule, used to connect calibration pulse generator and oscilloscope type instruments; The parameter adjustment submodule is used to adjust the charge parameters, including charge size, polarity and repetition rate; A scale determination submodule is used to collect a pulse voltage waveform using an oscilloscope-type instrument and determine whether the pulse voltage waveform has a certain horizontal scale and vertical scale; The noise voltage waveform storage submodule is used to close the pulse generator charge output switch while keeping the horizontal and vertical scale positions unchanged, and store the noise voltage waveform signal U of the measurement circuit displayed by the oscilloscope instrument. noise .

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