Error correction method and system for lightning arrester live detection device

Abstract

The invention discloses an error correction method for a lightning arrester live detection device, and the method achieves the real-time dynamic compensation of the error of the lightning arrester live detection device through the self-inspection of the lightning arrester live detection device, the collection of background noise, the injection of standard resistive current, and the verification of the full-link gain error. And the lightning arrester live detection device carries out periodic depth calibration according to compensated data and judges errors, so that a compensation coefficient table is updated, and stepped standard current is re-injected for testing. According to the scheme, corresponding compensation models are respectively designed through dynamic compensation, so that a dynamic compensation system is automatically started for self-correction every time the equipment is started, meanwhile, a period depth calibration system is designed, a step standard current is injected for period test, a coefficient table of the compensation models is updated according to errors, and the compensation accuracy is improved. Therefore, the compensation of the equipment is non-linearly changed along with the clock, and the device has the characteristics of high precision, nonlinearity and self-adaption, thereby ensuring the error precision and prolonging the service life of the equipment.

Description

Technical Field

[0001] This invention belongs to the field of power, specifically a method and system for error correction of a surge arrester live detection device. Background Technology

[0002] A surge arrester live-line detection device is a device that monitors the leakage current, harmonic components, and phase angle of a surge arrester in real time. Based on the monitoring results, it determines the aging, moisture, or damage status of the arrester. It mainly consists of a high-precision current transformer, voltage probe, AD converter, digital signal processor, interactive module, and communication module.

[0003] However, existing surge arrester live-line testing devices, excluding external interference and measurement errors, are prone to slight errors due to the inherent hardware accuracy and signal processing algorithms. Current industry error standards specify resistive current measurement error ≤5% and phase angle error ≤1°. In practical applications, existing testing devices typically compensate for these errors by referring to a clock table and using a lookup table method for automatic parameter fixing. While this method is simple to operate and applicable to offline devices, its drawbacks are significant. Over time, the error gradually drifts, eventually exceeding industry standard requirements, thus impacting the device's lifespan. To address this issue, a surge arrester live-line testing device error correction method and system are provided. Summary of the Invention

[0004] To address the above problems, the present invention aims to provide an error correction method and system for a surge arrester live-line detection device.

[0005] The specific technical solution for achieving the objective of this invention is as follows:

[0006] A method for correcting errors in a surge arrester live-line detection device includes the following steps:

[0007] Step 1: Through the self-test of the surge arrester live detection device, collect the background noise and inject standard resistive current to verify the full-link gain error;

[0008] Step 2: Perform real-time dynamic compensation for the error of the surge arrester live detection device;

[0009] Step 3: The surge arrester live-line testing device performs periodic deep calibration based on the compensated data, compares the measured value with the standard source error, and judges the error. If the error is less than the threshold, a calibration report is directly generated and the calibration is passed; otherwise, the compensation coefficient table is updated and a stepped standard current is re-injected for testing.

[0010] An error correction system for a surge arrester live-line detection device includes the following steps:

[0011] Self-test calibration module: Used for self-testing of the surge arrester live-line detection device, collecting background noise and injecting standard resistive current, verifying the full-link gain error, and realizing the automatic online correction of the surge arrester live-line detection device upon startup;

[0012] Data acquisition module: used to acquire real-time data of CT, PT, temperature, and clock from the surge arrester live detection device;

[0013] Signal calibration module: Uses standard current and voltage to calibrate and test the surge arrester live detection device, and determines the error range based on the test results;

[0014] Error correction module: By collecting data and calibration test information, it determines the source and range of error, and realizes periodic automatic correction of the compensation coefficient through online parameter updates.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] (1) The present invention designs a dynamic compensation scheme and designs corresponding compensation models from the hardware, signal processing and algorithm levels respectively, so as to realize the self-correction of the automatic start-up state compensation system every time the device is powered on. At the same time, by designing a periodic depth calibration system, periodic testing is performed by injecting a stepped standard current, and the coefficient table of the compensation model is updated according to the error, so that the coefficient table is adaptively adjusted with the aging of the device, so that the compensation of the device changes nonlinearly with the clock, and has the characteristics of high precision, nonlinearity and self-adaptation, thereby ensuring error accuracy and extending the service life of the device.

[0017] (2) The present invention collects data information and calibration test information to determine the source and range of error, and realizes periodic automatic correction of compensation coefficient. It has the characteristics of automation, full cycle and high sensitivity, and does not require manual updating of compensation coefficient table.

[0018] The present invention will be further described below with reference to specific embodiments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the error correction method for the surge arrester live detection device of the present invention.

[0020] Figure 2 This is a flowchart illustrating the periodic calibration process of the present invention.

[0021] Figure 3 This is a schematic diagram illustrating the sources of error in the solution of this invention.

[0022] Figure 4 This is a schematic diagram of the error correction system for the surge arrester live detection device in an embodiment of the present invention. Detailed Implementation

[0023] Example

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0026] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0027] Combination Figure 1 A method for correcting errors in a surge arrester live-line detection device includes the following steps:

[0028] Step 1: Through the self-test of the surge arrester live detection device, collect the background noise and inject standard resistive current to verify the full-link gain error;

[0029] Step 2: Perform real-time dynamic compensation for the error of the surge arrester live detection device;

[0030] The error sources of the surge arrester live detection device include current transformer error, voltage synchronization channel error, and signal processing error.

[0031] The errors of the current transformer include nonlinearity error, small current drift error and temperature drift error. In actual situations, these three types of errors may coexist. Error correction should be carried out according to the solution designed below, based on the requirements.

[0032] Specifically, the nonlinear error of the frequency response of the current transformer is corrected in real time by constructing a pre-calibration compensation model using pre-stored frequency-amplitude response curves.

[0033]

[0034] in, This indicates the corrected current value; This represents the sensor's original measurement value; The frequency compensation gain function is obtained by looking up a table from a pre-stored frequency-amplitude response curve.

[0035] For small current drift errors, adaptive zero-point calibration is used. During the daily self-test of the surge arrester live detection device, the input terminal of the current transformer is shorted to collect the background noise and store it as an offset, which is automatically deducted during measurement.

[0036] To compensate for temperature drift error, a polynomial temperature compensation model is established by integrating a temperature sensor into the surge arrester's live detection device, as shown in the following formula;

[0037]

[0038]

[0039] in, This indicates the temperature drift of the measured current value; Indicates real-time temperature Compared with reference temperature The difference; It represents the first-order temperature coefficient, reflecting the linear drift trend; It represents the second-order temperature coefficient, reflecting nonlinear drift characteristics.

[0040] In addition, in some embodiments, the error of the current transformer can also be compensated using a current compensation formula:

[0041]

[0042] in, Indicates frequency offset. Indicates temperature difference. This indicates the corrected current value; Indicates the original measured current. The frequency attenuation coefficient is fitted by the frequency response curve of the current transformer; This is the temperature gain coefficient.

[0043] The voltage synchronization channel error includes PT angle difference, signal sampling jitter error, and ADC quantization error;

[0044] The PT angle difference is used to achieve real-time phase offset pre-compensation through a pre-stored PT angle difference mapping table under different loads;

[0045] In addition, voltage synchronization channel errors include PT angle difference, signal sampling jitter error, and ADC quantization error;

[0046] The phase offset pre-compensation amount in the PT angle difference mapping table under different loads is obtained by constructing a dynamic compensation model:

[0047]

[0048] in, This indicates the corrected phase angle. This represents the original measured phase angle including errors, where T represents temperature and U represents voltage fluctuation. This represents the temperature-phase drift coefficient, obtained through oven calibration. This represents the electrical-phase nonlinearity coefficient, calibrated through a PT load test.

[0049] The signal sampling jitter error is compensated by constructing an anti-aliasing filter group delay compensation model and performing reverse time shift on the output of the IR filter in the surge arrester live detection device.

[0050]

[0051] in The signal delay after passing through the filter is represented by N; the order of the IR filter is represented by N; and the sampling frequency is represented by fs.

[0052] The ADC quantization error is corrected using a combination of oversampling and noise shaping, utilizing a 24-bit ADC operating at a 256× oversampling rate. The modulation frequency of the modulator is synchronized with the operating frequency of the ADC after 256× oversampling, ensuring that the high-frequency band of noise transfer is completely away from the target signal band, avoiding interference of modulation noise with the effective signal, and reducing the noise floor.

[0053] The signal processing errors include spectral leakage error, harmonic interference error, and phase calculation deviation.

[0054] Step 3: The surge arrester live-line testing device performs periodic deep calibration based on the compensated data, compares the measured value with the standard source error, and judges the error. If the error is less than the threshold, a calibration report is directly generated and the calibration is passed; otherwise, the compensation coefficient table is updated and a stepped standard current is re-injected for testing.

[0055] In periodic depth calibration, the error of the surge arrester live detection device is corrected using a compensation coefficient table;

[0056] The compensation coefficient is:

[0057]

[0058] Among them, This indicates that the standard source outputs precise current. This indicates the recorded measurement value from the detector;

[0059] The compensation coefficient table stores the compensation coefficients according to the operating condition coordinates, including temperature, frequency, and range.

[0060] During correction, if the current working condition (T, f, Range) has a record in the compensation coefficient table, it is directly called; if the current working condition falls between the entries in the compensation coefficient table, bilinear interpolation is used to calculate the compensation coefficient.

[0061]

[0062] Where K represents the final calculated compensation coefficient, T represents the current actual temperature value, T0 represents the reference temperature value, T1 represents another reference temperature value in the temperature dimension, which, together with T0, determines the temperature variation range, f represents the current actual frequency value, f0 represents the reference frequency value, and f1 represents another reference frequency value in the frequency dimension, which, together with f0, determines the frequency variation range. This represents the basic compensation coefficient at temperature T0 and frequency f0. This represents the compensation coefficient under the operating condition of temperature T1 and frequency f0. This represents the compensation coefficient at temperature T0 and frequency f1.

[0063] This solution employs a dynamic compensation approach, designing corresponding compensation models at the hardware, signal processing, and algorithm levels. It performs real-time error correction for nonlinear errors, small current drift, and temperature drift in current transformers. During signal transmission, a dynamic compensation model is established for phase offset pre-compensation at the PT angle difference, compressing the phase error caused by PT angle difference and temperature drift from above 2° to no more than 0.3°. This enables the self-correction of the compensation system upon each power-on. Simultaneously, a periodic deep calibration system is designed, performing periodic tests by injecting stepped standard current and updating the coefficient table of the compensation model based on the error. This allows the coefficient table to adaptively adjust as the equipment ages, resulting in nonlinear compensation that changes with the clock. This approach features high precision, nonlinearity, and adaptability, ensuring error accuracy and extending equipment lifespan.

[0064] The present invention also provides an error correction system for a surge arrester live-line detection device, comprising the following modules:

[0065] Self-test calibration module: Adopting digital twin + AI optimization technology, through the self-test of the surge arrester live detection device, the background noise is collected and a standard resistive current is injected to verify the full-link gain error and realize the automatic online correction of the surge arrester live detection device after power-on;

[0066] Data acquisition module: used to acquire real-time data of CT, PT, temperature, and clock from the surge arrester live detection device;

[0067] Signal calibration module: Uses standard current and voltage to calibrate and test the surge arrester live detection device, and determines the error range based on the test results;

[0068] Error correction module: By collecting data and calibration test information, it determines the source and range of error, and achieves periodic automatic correction of the compensation coefficient through online parameter updates. This embodiment is equipped with a real-time compensation engine, which determines the source and range of error by collecting data and calibration test information, and achieves periodic automatic correction of the compensation coefficient through online OTA parameter updates.

[0069] This solution also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps:

[0070] Step 1: Through the self-test of the surge arrester live detection device, collect the background noise and inject standard resistive current to verify the full-link gain error;

[0071] Step 2: Perform real-time dynamic compensation for the error of the surge arrester live detection device;

[0072] Step 3: The surge arrester live-line testing device performs periodic deep calibration based on the compensated data, compares the measured value with the standard source error, and judges the error. If the error is less than the threshold, a calibration report is directly generated and the calibration is passed; otherwise, the compensation coefficient table is updated and a stepped standard current is re-injected for testing.

[0073] The embodiments described above are merely one implementation method of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for correcting errors in a surge arrester live-line detection device, characterized in that, Includes the following steps: Step 1: Through the self-test of the surge arrester live detection device, collect the background noise and inject standard resistive current to verify the full-link gain error; Step 2: Perform real-time dynamic compensation for the error of the surge arrester live detection device; Step 3: The surge arrester live-line testing device performs periodic deep calibration based on the compensated data, compares the measured value with the standard source error, and judges the error. If the error is less than the threshold, a calibration report is directly generated and the calibration is passed; otherwise, the compensation coefficient table is updated and a stepped standard current is re-injected for testing.

2. The error correction method for the surge arrester live-line detection device according to claim 1, characterized in that, The error sources of the surge arrester live detection device include current transformer error, voltage synchronization channel error, and signal processing error.

3. The error correction method for the surge arrester live-line detection device according to claim 2, characterized in that, The errors of the current transformer include nonlinearity error, small current drift error, and temperature drift error: Specifically, the nonlinear error of the frequency response of the current transformer is corrected in real time by constructing a pre-calibration compensation model using pre-stored frequency-amplitude response curves. ； in, This indicates the corrected current value; This represents the sensor's original measurement value; The frequency compensation gain function is obtained by looking up a table from a pre-stored frequency-amplitude response curve. For small current drift errors, adaptive zero-point calibration is used. During the daily self-test of the surge arrester live detection device, the input terminal of the current transformer is shorted to collect the background noise and store it as an offset, which is automatically deducted during measurement. To compensate for temperature drift error, a polynomial temperature compensation model is established by integrating a temperature sensor into the surge arrester's live detection device, as shown in the following formula; ； ； in, This indicates the temperature drift of the measured current value; Indicates real-time temperature Compared with reference temperature The difference; It represents the first-order temperature coefficient, reflecting the linear drift trend; It represents the second-order temperature coefficient, reflecting nonlinear drift characteristics.

4. The error correction method for the surge arrester live-line detection device according to claim 2, characterized in that, The voltage synchronization channel error includes PT angle difference, signal sampling jitter error, and ADC quantization error; The PT angle difference is used to achieve real-time phase offset pre-compensation through a pre-stored PT angle difference mapping table under different loads; The signal sampling jitter error is compensated by constructing an anti-aliasing filter group delay compensation model and performing reverse time shift on the output of the IR filter in the surge arrester live detection device. ； in The signal delay after passing through the filter is represented by N; the order of the IR filter is represented by N; and the sampling frequency is represented by fs. The ADC quantization error is corrected using a combination of oversampling and noise shaping, utilizing a 24-bit ADC operating at a 256× oversampling rate. Modulator modulation reduces the noise floor.

5. The error correction method for the surge arrester live-line detection device according to claim 4, characterized in that, The voltage synchronization channel error includes PT angle difference, signal sampling jitter error, and ADC quantization error; The phase offset pre-compensation amount in the PT angle difference mapping table under different loads is obtained by constructing a dynamic compensation model: ； in, This indicates the corrected phase angle. This represents the original measured phase angle including errors, where T represents temperature and U represents voltage fluctuation. This represents the temperature-phase drift coefficient, obtained through oven calibration. This represents the electrical-phase nonlinearity coefficient, calibrated through a PT load test.

6. The error correction method for the surge arrester live-line detection device according to claim 2, characterized in that, The signal processing errors include spectral leakage error, harmonic interference error, and phase calculation deviation.

7. The error correction method for the surge arrester live-line detection device according to claim 2, characterized in that, The error of the current transformer is compensated using a current compensation formula: ； in, Indicates frequency offset. Indicates temperature difference. This indicates the corrected current value; Indicates the original measured current. The frequency attenuation coefficient is fitted by the frequency response curve of the current transformer; This is the temperature gain coefficient.

8. The error correction method for the surge arrester live-line detection device according to claim 1, characterized in that, The error of the surge arrester live detection device is corrected by a compensation coefficient table; The compensation coefficient is: ； Among them, This indicates that the standard source outputs precise current. This indicates the recorded measurement value from the detector; The compensation coefficient table stores the compensation coefficients according to the operating condition coordinates, including temperature, frequency, and range. During correction, if the current working condition has a record in the compensation coefficient table, it is directly retrieved; if the current working condition falls between entries in the compensation coefficient table, bilinear interpolation is used to calculate the compensation coefficient. ； Where K represents the final calculated compensation coefficient, T represents the current actual temperature value, T0 represents the reference temperature value, T1 represents another reference temperature value in the temperature dimension, which, together with T0, determines the temperature variation range, f represents the current actual frequency value, f0 represents the reference frequency value, and f1 represents another reference frequency value in the frequency dimension, which, together with f0, determines the frequency variation range. This represents the basic compensation coefficient at temperature T0 and frequency f0. This represents the compensation coefficient under the operating condition of temperature T1 and frequency f0. This represents the compensation coefficient at temperature T0 and frequency f1.

9. An error correction system for a surge arrester live-line detection device, characterized in that, Includes the following modules: Self-test calibration module: Used for self-testing of the surge arrester live-line detection device, collecting background noise and injecting standard resistive current, verifying the full-link gain error, and realizing the automatic online correction of the surge arrester live-line detection device upon startup; Data acquisition module: used to acquire real-time data of CT, PT, temperature, and clock from the surge arrester live detection device; Signal calibration module: Uses standard current and voltage to calibrate and test the surge arrester live detection device, and determines the error range based on the test results; Error correction module: By collecting data and calibration test information, it determines the source and range of error, and realizes periodic automatic correction of the compensation coefficient through online parameter updates.

10. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1-8.

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