Error correction method and device for non-intrusive voltage differential measurement, medium and product

Abstract

The invention discloses an error correction method and device for non-intrusive voltage differential measurement, a medium and a product, and relates to the technical field of voltage measurement, and the method is applied to a scene in which a differential electric field sensor array is arranged in a set range with a measured conductor as the center. Comprising the following steps: constructing an initial correction model based on a sensor distance and a measured conductor voltage; under the actual working condition, the initial correction model is processed through a least square method, and a correction model is obtained; when non-intrusive voltage differential measurement is carried out, the current measured conductor voltage and the sensor distance are obtained, and a correction coefficient is determined by adopting the correction model; and completing error correction of non-intrusive voltage differential measurement based on the correction coefficient. According to the invention, the complexity of an inversion algorithm and the special requirement on the spatial position of the sensor can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of voltage measurement, in particular to an error correction method, device, medium and product for non-intrusive voltage differential measurement. BACKGROUND

[0002] In high-voltage and ultra-high-voltage transmission lines, in order to maintain stable operation, real-time measurement of voltage needs to be realized. The traditional voltage measurement is an intrusive measurement method using a mutual inductor to access electrical equipment or high-voltage transmission lines. This method can cause high-frequency resonance when a transient fault occurs in the line, resulting in poor frequency response and narrow frequency band range of the sensing device. In addition, the mutual inductor has the problems of high cost, large size, difficulty in installation, and complex insulation structure, which is difficult to meet the intelligent and digital development trend of the power grid system.

[0003] Non-intrusive voltage measurement has the advantage of not directly invading electrical equipment or high-voltage transmission lines, and can achieve miniaturization and low-cost production, thus solving the problems of the intrusive measurement method. At present, the non-intrusive voltage measurement methods based on the electric field method mainly include the analog charge method and the electric field integration method. The analog charge method constructs a "field-source-voltage" mathematical model for voltage inversion, and in the implementation process, a plurality of electric field sensors can be used to form a differential array, thereby achieving better measurement accuracy.

[0004] However, the actual measurement conditions are complex, so multiple analog charges are needed to completely reflect the electric field distribution of the overall working condition, and then accurately invert the conductor voltage. Too many analog charges not only increase the complexity of the inversion algorithm, but also put higher requirements on the spatial position of the differential sensor. SUMMARY

[0005] To solve the above problems existing in the prior art, the present application provides an error correction method, device, medium and product for non-intrusive voltage differential measurement.

[0006] To achieve the above purpose, the present application provides the following solutions: In a first aspect, the present application provides an error correction method for non-intrusive voltage differential measurement, which is applied to a scenario where a differential electric field sensor array is arranged within a range set with a measured conductor as the center; the method comprises: constructing an initial correction model based on the sensor spacing and the measured conductor voltage; In the actual working condition, the least square method is used to process the initial correction model to obtain a correction model; When performing non-intrusive voltage differential measurement, the current measured conductor voltage and the sensor spacing are obtained, and the correction model is used to determine a correction coefficient; Based on the correction coefficient, the error correction of the non-intrusive voltage differential measurement is completed.

[0007] Optionally, the initial correction model is constructed based on the sensor spacing and the measured conductor voltage, comprising: An undisturbed equivalent model of voltage inversion based on the analog charge method is adopted to obtain the relationship between the electric field modulus difference value and the measured conductor voltage; The change value of the two-position sensor is obtained by considering the change of the electric field sensor reading at the two positions; the change value of the sensor is the electric field modulus difference value; Based on the relationship between the electric field modulus difference value and the measured conductor voltage, the corrected reading of the sensor is determined while maintaining the change value of the two-position sensor unchanged; Based on the corrected reading of the sensor and the electric field reading of the corresponding sensor under the interference condition, an initial correction coefficient model is determined; Based on the initial correction coefficient model, the relationship between the correction coefficient and the two-sensor spacing and the relationship between the correction coefficient and the measured conductor voltage are determined by fixing one sensor position; Based on the relationship between the correction coefficient and the two-sensor spacing and the relationship between the correction coefficient and the measured conductor voltage, the initial correction model is constructed.

[0008] Optionally, P 1 、P 2 The relationship between the electric field modulus difference value of the two-position sensor and the measured conductor voltage is represented as: ; In the formula, h H represents the height of the conductor geometric center to the ground, R 0 R represents the wire radius; l 1 、l 2 D represents the distance between the two sensors and the center of the measured conductor, V V represents the measured conductor voltage, E represents the electric field modulus difference value.

[0009] Optionally, the initial correction coefficient model is represented as: ; In the formula, k K represents the correction coefficient, E represents the electric field reading of the sensor at the position P 2 under the interference condition, E P2e V represents the measured conductor voltage, P 2 K represents the corrected reading of the sensor at the position.

[0010] Optionally, the relationship between the correction coefficient and the distance between the two sensors is expressed as: ; The relationship between the correction factor and the voltage of the measured conductor is expressed as follows: ; In the formula, k For correction factor, V The voltage of the conductor being measured. The distance between the two sensors, α , β, γ and p All parameters are yet to be determined.

[0011] Optionally, the initial modified model is represented as: ; In the formula, m, n, t These are all parameters to be determined under actual working conditions. k For correction factor, V The voltage of the conductor being measured is denoted as .

[0012] Optionally, the actual operating conditions include the voltage between the transformer terminals, the high-voltage bus voltage, the converter valve arm voltage, and the transmission line.

[0013] In a second aspect, this application 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 implement the steps of the error correction method for non-invasive voltage differential measurement provided above.

[0014] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the error correction method for non-invasive voltage differential measurement provided above.

[0015] Fourthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the error correction method for non-invasive voltage differential measurement provided above.

[0016] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides an error correction method, device, medium, and product for non-invasive voltage differential measurement. Considering the inconsistencies in differential sensor readings under actual operating conditions, the initial correction model is processed using the least squares method under actual operating conditions to obtain a correction model applicable to any measured conductor voltage and any sensor spacing under different operating conditions. This achieves error correction for non-invasive voltage differential measurement, reduces the complexity of the inversion algorithm, and alleviates the special requirements for sensor spatial position. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating an error correction method for non-invasive voltage differential measurement according to an embodiment of this application. Figure 2 A schematic diagram of a simulated charge method provided in an embodiment of this application; Figure 3 A schematic diagram of the fitting plane in an actual working condition with a conductor exhibiting strong interference, provided as an embodiment of this application; Figure 4 A schematic diagram of simulation modeling of the converter valve bridge arm voltage provided in an embodiment of this application; Figure 5 A schematic diagram showing the deployment location of a differential sensor array provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] In an exemplary embodiment, this application provides an error correction method for non-invasive differential voltage measurement. This method is executed by a computer device, specifically a terminal or server, or both. In this embodiment, the method is described using a server as an example. This method is applied in scenarios where a differential electric field sensor array is arranged within a defined range centered on the conductor being measured. Figure 1 As shown, it includes: Step 100: Construct an initial correction model based on the sensor spacing and the voltage of the conductor being measured.

[0022] Step 101: Under actual operating conditions, the initial modified model is processed using the least squares method to obtain the modified model. Actual operating conditions include, but are not limited to, scenarios such as inter-terminal voltage of the transformer, high-voltage bus voltage, converter valve arm voltage, and transmission lines.

[0023] Step 102: When performing non-invasive voltage differential measurement, the current voltage of the conductor being measured and the sensor spacing are obtained, and the correction coefficient is determined using a correction model. The electric field sensor used in this application can be any type of electric field sensing device, such as capacitive, photoelectric, field-milled, or micro-electro-mechanical system (MEMS), and the specific implementation method is not limited.

[0024] Step 103: Perform error correction for non-invasive voltage differential measurement based on the correction coefficient.

[0025] By implementing steps 100-103 above, this application corrects the readings of the differential electric field sensor under fixed operating conditions, thereby improving the voltage inversion accuracy.

[0026] In another exemplary embodiment of this application, in order to discuss the correction method and summarize the relationship between the correction coefficient and the measured conductor voltage and the sensor spacing, simulation data from actual working conditions are used for fitting to obtain a correction function (i.e., an initial correction model) applicable to any measured conductor voltage and any sensor spacing under different working conditions, thereby facilitating flexible adjustment based on specific scenarios. Therefore, the implementation process of step 100 provided above in this application can be replaced by the following steps 200-205.

[0027] Step 200: Using an interference-free equivalent model based on the simulated charge method for voltage inversion, the relationship between the electric field modulus difference and the voltage of the measured conductor is obtained.

[0028] In practical applications, this step corresponds to the derivation of the interference-free voltage inversion formula. For example, Figure 2As shown, the interference-free equivalent model for voltage inversion based on the simulated charge method is theoretically... P 1 、P 2 The relationship between the electric field modulus difference between the two position sensors and the voltage of the measured conductor is expressed as follows: (1) In the formula, h Indicates the height of the conductor's geometric center above the ground. R 0 Indicates the radius of the conductor. l 1 、l 2 The distances between the two sensors and the center of the conductor being measured are denoted as , where ... l 2 >l 1 . V The voltage of the conductor being measured. This represents the electric field modulus difference. Figure 2 middle, The equivalent simulated line charge of the conductor under test. d The coordinates are the horizontal position of the geometric center of the conductor being measured.

[0029] Step 201: Consider the changes in the readings of the electric field sensors at the two locations to obtain the changes in the sensor values ​​at the two different locations. The changes in the sensor values ​​are the electric field mode difference values.

[0030] In practical applications, the electric field difference is first compared under different scenarios. Specifically, in the absence of interference, the difference is recorded as... P 1 、P 2 The electric field modulus at the points are respectively E P1 , E P2 Then the electric field modulus difference Δ E It can be represented as: (2) After an interference source is introduced, it will interfere with the electric field sensors at different locations, causing changes in their readings. When the distance between the interference source and the sensor is sufficiently large, or when the intensity of the interference source is sufficiently low, the interference caused by the interference source to the two sensors is approximately the same, and the electric field mode difference is also approximately equal to Δ. E However, when the interference source is close to the sensor or the interference intensity is high, the interference caused by the interference source to the two sensors cannot be approximated as equal. Let this be denoted as... P 1 、P 2 The electric field modulus at the points are respectivelyE ’ P1 , E ’ P2 The electric field mode difference Δ after being affected by the disturbance E ’ It can be represented as: (3) If no correction is used, then Δ E With Δ E ’ Even small numerical differences between the sensors can cause proportional fluctuations in the voltage inversion results, thus affecting the accuracy of voltage measurement. Theoretically, by infinitely reducing the sensor spacing, the electric field modulus difference with and without electric field interference can be approximated to zero, thereby reducing voltage inversion errors. However, this approach is difficult to implement due to limitations in the actual sensor size and resolution. To address this issue, this application provides a method for correcting single-sensor readings. Specifically, it considers the changes in the electric field sensor readings at two locations, and denotes... P 1 、P 2 The sensor changes at each location are Δ E P1 and Δ E P2 Its expression is shown in equations (4) and (5).

[0031] (4) (5) In the formula, E P1 , E P2 In the absence of interference P 1 、P 2 The electric field reading of the sensor at that location, E’ P1 , E’ P2 In case of interference P 1 、P 2 The electric field reading of the sensor at the location.

[0032] Step 202: Based on the relationship between the electric field modulus difference and the voltage of the conductor being measured, determine the corrected reading of the sensor while keeping the changes in the two position sensors constant.

[0033] In practical applications, to maintain the difference constant, P2 Corrected readings of the electric field sensor E P2e It should be: (6) Step 203: Determine the initial correction coefficient model based on the corrected sensor readings and the corresponding electric field readings of the sensor under interference conditions. For example, define... P 2 Correction factor for sensor readings k To express the ratio of the corrected electric field to the uncorrected electric field under disturbed conditions, the initial correction coefficient model is expressed as: (7) In the formula, k This is a correction factor. Based on the principles of electromagnetism, k It is usually not a constant, but a function related to the voltage value of the conductor being measured and the distance between the sensors.

[0034] Step 204: Using a fixed sensor position, determine the relationship between the correction coefficient and the distance between the two sensors, as well as the relationship between the correction coefficient and the voltage of the conductor being measured, based on the initial correction coefficient model.

[0035] In practical applications, fixed l 1. By fitting the experimental data, it can be found that the correction coefficient is linearly related to the distance between the two sensors and the reciprocal of the measured voltage, as shown in Equation (8) and Equation (9), respectively.

[0036] (8) (9) in, α, β, γ, p This is a parameter to be determined, as it depends on the actual operating conditions and requires simulation to be performed for different specific conditions. The distance between the two sensors... .

[0037] Step 205: Based on the relationship between the correction coefficient and the distance between the two sensors, and the relationship between the correction coefficient and the voltage of the measured conductor, construct an initial correction model. The initial correction model is expressed as: (10) In the formula, m, n, t These are all undetermined parameters under actual working conditions. Here, to simplify the initial correction model and reduce dimensionality, Δ is ignored. l The constant term in a linear relationship, i.e., 1 / V item.

[0038] Based on the above description, in step 101, the above formula (10) can be used to perform least squares fitting on the actual working conditions to determine the... V Δ l The functional relationship between them. The fitting plane for the actual working conditions is as follows: Figure 3 As shown. Figure 3 middle, x The axis represents the sensor spacing Δ. l , y The axis is the ratio Δ of the sensor spacing to the voltage of the measured conductor. l / V , z The axis is a correction factor. k The value of .

[0039] Furthermore, in practical applications, the coefficient correction method of the electric field sensor provided in this application is not specifically limited, as long as the difference in readings of the differential electric field sensor before and after correction is consistent.

[0040] In another exemplary embodiment of this application, simulation verification is performed. Key parameters during the simulation verification process are set as follows: The high-voltage conductor under test has a diameter of 30cm, and its geometric center is 17.5m above the ground. The interfering conductor is perpendicular to the conductor under test, 11m above the ground, and 6m away from the conductor under test at a horizontal distance. The sensor 1 is positioned P1 5cm from the conductor surface, which is 20cm from the center of the conductor, and its tilt angle is 315°.

[0041] Figure 4 This is a schematic diagram of the simulation model for the converter valve bridge arm voltage. Its key models include the conductor under test, the interfering conductor, and the sensor array. Figure 5 The location of sensor 1 is where the differential sensor array is deployed. P 1. The location of sensor 2 is as follows: P 2. Under the premise of fixing the distance from the near-end sensor to the conductor, the simulation process involves two variables: sensor spacing and the voltage of the measured conductor. In an exemplary embodiment of this application, the sensor spacing is fixed, and the form of the measured conductor voltage is adjusted. The voltage inversion values ​​before and after correction, as well as the inversion accuracy, are calculated. Specific data are shown in Tables 1 and 2. It can be seen that the absolute value of the corrected inversion accuracy is reduced to below 0.05%FS. Furthermore, in this embodiment, the expression for the correction coefficient in the converter valve arm voltage condition is obtained through fitting: (11) Its correlation coefficient R 2 =0.99994. At this point, changes in voltage and sensor spacing can be corrected using this coefficient function to maintain inversion accuracy.

[0042] Table 1 Voltage inversion values ​​and inversion accuracy before correction

[0043] Table 2. Voltage inversion values ​​and inversion accuracy before correction

[0044] In summary, the error correction method for non-invasive differential voltage measurement provided in this application corrects the readings of differential electric field sensors under fixed operating conditions, thereby improving the accuracy of voltage inversion. This application employs a method of arranging a differential electric field sensor array around the conductor being measured, combining simulations with parameters from the actual operating conditions to obtain the electric fields under interference-free and actual operating conditions, and corrects the difference in electric field values ​​under the actual operating conditions, thus improving the accuracy of voltage inversion.

[0045] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 6 As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The database stores error correction data for non-invasive voltage differential measurements. The I / O interfaces allow the processor to exchange information with external devices. The communication interface allows communication with external terminals via a network connection. When executed by the processor, the computer program implements an error correction method for non-invasive voltage differential measurements.

[0046] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0047] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0048] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0049] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0050] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0051] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (RRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0052] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0053] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for error correction of non-intrusive voltage differential measurements, characterized in that, The method is applied to a scenario where a differential electric field sensor array is arranged in a range centered on a measured conductor; the method comprises: constructing an initial correction model based on sensor spacing and measured conductor voltage; under actual working conditions, processing the initial correction model using a least square method to obtain a correction model; when performing non-intrusive voltage differential measurement, obtaining the current measured conductor voltage and sensor spacing, and using the correction model to determine a correction coefficient; based on the correction coefficient, completing error correction of non-intrusive voltage differential measurement.

2. The error correction method for non-invasive voltage differential measurement according to claim 1, characterized in that, Constructing an initial correction model based on sensor spacing and measured conductor voltage comprises: using an undisturbed equivalent model of voltage inversion based on the analog charge method to obtain the relationship between electric field modulus difference and measured conductor voltage; considering the change of the readings of the electric field sensors at two positions, obtaining the change values of the sensors at the two positions; the change value of the sensor is the electric field modulus difference; based on the relationship between electric field modulus difference and measured conductor voltage, determining the corrected readings of the sensors while maintaining the change values of the sensors at the two positions unchanged; based on the corrected readings of the sensors and the electric field readings of the corresponding sensors under interference, determining an initial correction coefficient model; using a fixed sensor position, determining the relationship between the correction coefficient and the spacing between the two sensors and the relationship between the correction coefficient and the measured conductor voltage based on the initial correction coefficient model; based on the relationship between the correction coefficient and the spacing between the two sensors and the relationship between the correction coefficient and the measured conductor voltage, constructing the initial correction model.

3. The error correction method for non-invasive voltage differential measurements according to claim 2, characterized in that, P 1 、 P 2 The relationship between the difference in the electric field mode of the two sensors and the measured conductor voltage is given by: ； wherein h represents the height of the conductor geometric center from the ground, R 0 represents the wire radius, l 1 、l 2 is the distance between the two sensors and the center of the measured conductor, V is the voltage of the measured conductor, is the difference of the electric field modulus.

4. The error correction method for non-invasive voltage differential measurement according to claim 2, characterized in that, The initial correction coefficient model is expressed as: ； wherein k is a correction factor, is the sensor reading in the presence of interference P 2 is the sensor reading in the presence of interference E P2e is the sensor reading in the presence of interference P 2 is the sensor reading in the presence of interference 5. The error correction method for non-invasive voltage differential measurement according to claim 2, characterized in that, the relationship between the correction coefficient and the spacing between the two sensors is expressed as: ； the relationship between the correction coefficient and the measured conductor voltage is expressed as: ； wherein k is a correction factor, V is the measured conductor voltage, is the distance between the two sensors, α , β, γ and p are undetermined parameters.

6. The error correction method for non-invasive voltage differential measurement according to claim 2, characterized in that, The initial correction model is expressed as: ； wherein, m, n, t are to-be-determined parameters in actual working conditions, k is a correction coefficient, V is a measured conductor voltage.

7. The error correction method for non-invasive voltage differential measurement according to claim 1, characterized in that, The actual working conditions include flat terminal voltage, high-voltage bus voltage, converter valve bridge arm voltage, and power transmission line.

8. A computer device comprising: A memory, a processor, and a computer program stored on the memory and capable of running on the processor, characterized in that the processor executes the computer program to implement the error correction method for non-intrusive voltage differential measurement according to any one of claims 1-7.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the error correction method for non-intrusive voltage differential measurement according to any one of claims 1-7.

10. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the error correction method for non-intrusive voltage differential measurement according to any one of claims 1-7.

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