Stray parameter determination methods, apparatus, equipment, storage media, and program products

Abstract

This application relates to a method, apparatus, device, storage medium, and program product for determining stray parameters. The method includes: applying a unit pulse voltage excitation to a capacitive voltage transformer and determining the frequency response characteristic curve of the capacitive voltage transformer; obtaining an equivalent circuit model of the capacitive voltage transformer; and determining the stray parameters of the capacitive voltage transformer based on the minimum and maximum values ​​in the equivalent circuit model and the frequency response characteristic curve. This method can accurately determine stray parameters.

Description

Technical Field

[0001] This application relates to the field of capacitive voltage transformer technology, and in particular to a method, apparatus, device, storage medium, and program product for determining stray parameters. Background Technology

[0002] Stray capacitance in a capacitive voltage transformer (CVT) is caused by factors such as its circuit layout, the physical positional relationship between components, and the external environment. These capacitances are not explicitly planned or anticipated at the beginning of the CVT design, but are formed naturally as the circuit is actually constructed and the external environment influences them. Stray capacitance can significantly affect the performance of the CVT.

[0003] Currently, the accuracy in determining the parameters of CVT stray capacitance is low. Summary of the Invention

[0004] Therefore, it is necessary to provide a stray parameter determination method, apparatus, equipment, storage medium, and program product that can improve the accuracy of stray capacitance parameter determination for capacitive voltage transformers, addressing the aforementioned technical problems.

[0005] In a first aspect, this application provides a method for determining stray parameters, including:

[0006] A unit pulse voltage excitation is applied to a capacitive voltage transformer, and the frequency response characteristic curve of the capacitive voltage transformer is determined.

[0007] Obtain the equivalent circuit model of the capacitive voltage transformer;

[0008] Based on the minimum and maximum values ​​in the equivalent circuit model and frequency response characteristic curve, the stray parameters of the capacitive voltage transformer are determined.

[0009] In one embodiment, the equivalent circuit model of the capacitive voltage transformer includes a voltage divider capacitor, a compensating reactor, a transformer, and a damper. The compensating reactor includes the inductance of the compensating reactor coil, the resistance of the compensating reactor coil, and a first stray capacitance. The inductance and resistance of the compensating reactor coil are connected in series to form a first series branch. The first series branch is connected in parallel with the first stray capacitance, and the first terminal of the first series branch is connected in series with the voltage divider capacitor. The transformer includes winding inductance, winding resistance, stray capacitance to ground, and a second stray capacitance. The winding inductance and winding resistance are connected in series to form a second series branch. The second series branch is connected in parallel with the second stray capacitor. The first end of the second series branch is connected to the second end of the first series branch and the first end of the stray capacitor to ground. The damper includes a damping inductor, a damping resistor and a third stray capacitor. The damping inductor and damping resistor are connected in series to form a third series branch. The third series branch is connected in parallel with the third stray capacitor. The first end of the third series branch is connected to the second end of the second series branch and the second end of the third series branch is connected to the second end of the stray capacitor to ground.

[0010] In one embodiment, the stray parameters of the capacitive voltage transformer are determined based on the minimum and maximum values ​​in the equivalent circuit model and frequency response characteristic curve, including: determining the stray parameters of the first stray capacitor and the second stray capacitor based on the minimum values ​​in the frequency response characteristic curve; and determining the stray parameters of the third stray capacitor and the stray capacitor to ground based on the maximum values ​​in the frequency response characteristic curve and the stray parameters of the first stray capacitor and the second stray capacitor.

[0011] In one embodiment, determining the spurious parameters of the third spurious capacitor and the spurious capacitor to ground based on the maximum value in the frequency response characteristic curve and the spurious parameters of the first and second spurious capacitors includes: obtaining an objective function, which may be a frequency response characteristic expression of an equivalent circuit model, the frequency response characteristic expression being determined by the maximum value, minimum value, and each spurious parameter; determining the maximum value of the objective function according to a preset optimization algorithm; and determining the spurious parameters of the third spurious capacitor and the spurious capacitor to ground based on the maximum value.

[0012] In one embodiment, the maximum value of the objective function is determined according to a preset optimization algorithm, and the spurious parameters of the third spurious capacitor and the spurious capacitor to ground are determined based on the maximum value. This includes: obtaining the initial spurious parameters of the third spurious capacitor and the spurious capacitor to ground; determining the search range based on each initial spurious parameter, and determining multiple sets of parameter combinations based on each search range, the parameter combinations including candidate spurious parameters of the third spurious capacitor and candidate spurious parameters of the spurious capacitor to ground; calculating the objective function based on each parameter combination, and determining the spurious parameters of the third spurious capacitor and the spurious capacitor to ground based on the parameter combination when the objective function reaches its maximum value.

[0013] In one embodiment, the minimum value in the frequency response characteristic curve includes a first minimum value and a second minimum value. Determining the stray parameters of the first stray capacitance and the second stray capacitance based on the minimum value in the frequency response characteristic curve includes: determining the stray parameters of the first stray capacitance based on the first minimum value, the inductance of the compensation reactor coil, and the resistance of the compensation reactor coil; and determining the stray parameters of the second stray capacitance based on the second minimum value, the winding inductance, and the winding resistance.

[0014] Secondly, this application also provides a stray parameter determination device, comprising:

[0015] The first acquisition module is used to apply a unit pulse voltage excitation to the capacitive voltage transformer and determine the frequency response characteristic curve of the capacitive voltage transformer.

[0016] The second acquisition module is used to acquire the equivalent circuit model of the capacitive voltage transformer;

[0017] The determination module is used to determine the stray parameters of the capacitive voltage transformer based on the minimum and maximum values ​​in the equivalent circuit model and frequency response characteristic curve.

[0018] In one embodiment, the equivalent circuit model of the capacitive voltage transformer includes a voltage divider capacitor, a compensating reactor, a transformer, and a damper. The compensating reactor includes the inductance of the compensating reactor coil, the resistance of the compensating reactor coil, and a first stray capacitance. The inductance and resistance of the compensating reactor coil are connected in series to form a first series branch. The first series branch is connected in parallel with the first stray capacitance, and the first terminal of the first series branch is connected in series with the voltage divider capacitor. The transformer includes winding inductance, winding resistance, stray capacitance to ground, and a second stray capacitance. The winding inductance and winding resistance are connected in series to form a second series branch. The second series branch is connected in parallel with the second stray capacitor. The first end of the second series branch is connected to the second end of the first series branch and the first end of the stray capacitor to ground. The damper includes a damping inductor, a damping resistor and a third stray capacitor. The damping inductor and damping resistor are connected in series to form a third series branch. The third series branch is connected in parallel with the third stray capacitor. The first end of the third series branch is connected to the second end of the second series branch and the second end of the third series branch is connected to the second end of the stray capacitor to ground.

[0019] In one embodiment, the determining module is specifically configured to determine the spurious parameters of the first spurious capacitance and the second spurious capacitance based on the minimum values ​​in the frequency response characteristic curve; and to determine the spurious parameters of the third spurious capacitance and the spurious capacitance to ground based on the maximum values ​​in the frequency response characteristic curve and the spurious parameters of the first spurious capacitance and the second spurious capacitance.

[0020] In one embodiment, the determining module is specifically used to obtain the objective function, which may be the frequency response characteristic expression of the equivalent circuit model. The frequency response characteristic expression is determined by the maximum value, the minimum value, and various spurious parameters. The maximum value of the objective function is determined according to a preset optimization algorithm, and the spurious parameters of the third spurious capacitor and the spurious capacitor to ground are determined according to the maximum value.

[0021] In one embodiment, the determining module is specifically used to obtain the initial spurious parameters of the third spurious capacitance and the ground spurious capacitance; determine the search range according to each initial spurious parameter, and determine multiple sets of parameter combinations according to each search range, the parameter combinations including candidate spurious parameters of the third spurious capacitance and candidate spurious parameters of the ground spurious capacitance; calculate the objective function according to each parameter combination, and when the objective function reaches its maximum value, determine the spurious parameters of the third spurious capacitance and the ground spurious capacitance according to the parameter combination.

[0022] In one embodiment, the minimum values ​​in the frequency response characteristic curve include a first minimum value and a second minimum value. The determining module is specifically used to determine the stray parameters of the first stray capacitor based on the first minimum value, the inductance of the compensating reactor coil, and the resistance of the compensating reactor coil; and to determine the stray parameters of the second stray capacitor based on the second minimum value, the winding inductance, and the winding resistance.

[0023] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement any of the methods described in the first aspect above.

[0024] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the methods described in the first aspect above.

[0025] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements any of the methods described in the first aspect above.

[0026] The aforementioned method, apparatus, equipment, storage medium, and program product for determining stray parameters first apply a unit pulse voltage excitation to a capacitive voltage transformer (CVT) and determine its frequency response characteristic curve. Then, an equivalent circuit model of the CVT is obtained. Finally, the stray parameters of the CVT are determined based on the minimum and maximum values ​​in the equivalent circuit model and the frequency response characteristic curve. In this way, by determining the frequency response characteristic curve of the CVT, then identifying the resonant point of the CVT based on the frequency response characteristic curve, and finally determining the stray capacitance parameters using the equivalent circuit model, the accuracy of determining the stray capacitance parameters of the CVT can be effectively improved. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a flowchart illustrating a method for determining stray parameters in one embodiment;

[0029] Figure 2 This is an equivalent circuit model of a capacitive voltage transformer in one embodiment;

[0030] Figure 3 This is a schematic diagram of the amplitude-frequency characteristic curve of a typical capacitive voltage transformer in one embodiment;

[0031] Figure 4 This is a flowchart illustrating the steps for determining stray parameters of a capacitive voltage transformer in one embodiment.

[0032] Figure 5 This is a flowchart illustrating the steps for determining the stray parameters of the third stray capacitance and the stray capacitance to ground in one embodiment.

[0033] Figure 6 This is a flowchart illustrating the steps for determining the stray parameters of the third stray capacitance and the stray capacitance to ground in another embodiment.

[0034] Figure 7 This is a flowchart illustrating the steps for determining the stray parameters of the first stray capacitance and the second stray capacitance in one embodiment.

[0035] Figure 8 This is a flowchart illustrating the stray parameter determination method in another embodiment;

[0036] Figure 9 This is a schematic diagram of the amplitude-frequency characteristic curve of a capacitive voltage transformer as defined in one embodiment.

[0037] Figure 10 This is a schematic diagram showing the results of determining the stray parameters of the third stray capacitance and the stray capacitance to ground in one embodiment.

[0038] Figure 11 This is a structural block diagram of a stray parameter determination device in one embodiment;

[0039] Figure 12 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0041] Stray capacitance in a capacitive voltage transformer (CVT) is caused by factors such as its circuit layout, the physical positional relationship between components, and the external environment. These capacitances are not explicitly planned or anticipated at the beginning of the CVT design, but are formed naturally as the circuit is actually constructed and the external environment influences them. Stray capacitance can significantly affect the performance of the CVT.

[0042] Currently, the accuracy in determining the parameters of CVT stray capacitance is low.

[0043] In view of this, this application provides a stray parameter determination method that can accurately determine the parameters of stray capacitance. The stray parameter determination method provided in this application can be executed by a stray parameter determination device, which can be implemented by software, hardware, or a combination of both. It can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device. In the following method embodiments, the execution subject is always described using a computer device as an example. The computer device can be a server or a desktop computer; this application does not limit the specific type of computer device.

[0044] In one exemplary embodiment, such as Figure 1 As shown, a method for determining stray parameters is provided, including the following steps 101 to 103. Wherein:

[0045] S101, apply a unit pulse voltage excitation to the capacitive voltage transformer and determine the frequency response characteristic curve of the capacitive voltage transformer.

[0046] Optionally, a unit pulse voltage excitation is applied to the primary side of the capacitive voltage transformer, wherein the amplitude of the applied unit pulse voltage excitation does not exceed the saturation voltage of the capacitive voltage transformer.

[0047] Optionally, a capacitive voltage transformer is a high-voltage measuring device used in power systems. The saturation voltage of a capacitive voltage transformer can be the maximum voltage value it can withstand, which usually corresponds to the rated voltage of the device under test.

[0048] Optionally, when a pulse voltage excitation is applied to the primary side of the CVT, the CVT can be excited to generate a response in a wide frequency range. The pulse response of the secondary side of the CVT can be synchronously acquired by a data acquisition device and sent to a computer device. The computer device can then determine the frequency response characteristic curve of the capacitive voltage transformer based on the unit pulse voltage excitation and the pulse response, specifically according to the following formula:

[0049]

[0050] in, For frequency response characteristics, This is the pulse voltage excitation spectrum on the primary side. This is the impulse response spectrum of the secondary side.

[0051] Optionally, the primary side of the capacitive voltage transformer can be the input terminal, the secondary side can be the output terminal, and the acquisition device can be a common oscilloscope or waveform recorder, etc.

[0052] S102, obtain the equivalent circuit model of the capacitive voltage transformer.

[0053] Optional, such as Figure 2 As shown, the equivalent circuit model of the capacitive voltage transformer in this embodiment includes voltage dividing capacitors. Compensating reactors, transformers, and dampers; compensating reactors, including the inductance of the compensating reactor coil. The resistance of the compensating reactor coil and the first stray capacitance Inductance of the compensating reactor coil and the resistance of the compensating reactor coil The first series branch is formed by connecting the first series capacitor in series, and the first series branch is connected in parallel with the first stray capacitor. The first terminal of the first series branch is connected to the voltage divider capacitor. Series connection; transformer, including winding inductance Winding resistance Stray capacitance to ground Second stray capacitance Winding inductance and winding resistance This forms a second series branch, which is connected in series with the second stray capacitor. Parallel connection, the first terminal of the second series branch is connected to the second terminal of the first series branch and the stray capacitance to ground. The first end is connected to; a damper, including a damping inductor. Damping resistor and the third stray capacitance Damping inductor and damping resistor This forms a third series branch, which is connected in series with the third stray capacitor. In parallel connection, the first end of the third series branch is connected to the second end of the second series branch, and the second end of the third series branch is connected to the stray capacitance to ground. The second end is connected.

[0054] In another possible implementation, the equivalent circuit model can also be any other existing model.

[0055] Optional, Figure 2 In the equivalent circuit model shown, the excitation branch is ignored. The compensation reactor, the leakage reactance of the transformer winding, and the load side will all resonate in parallel due to stray capacitance. However, not all of these parallel resonances will be reflected in the frequency response characteristics of the CVT.

[0056] S103. Based on the minimum and maximum values ​​in the equivalent circuit model and frequency response characteristic curve, determine the stray parameters of the capacitive voltage transformer.

[0057] Optionally, according to the equivalent circuit model, since the branch where the damper is located (i.e., the load-side branch) is connected in series with the branch where the transformer is located, and then connected to the stray capacitance to ground on the primary side... Therefore, when parallel resonance occurs in the branch containing the damper, although the equivalent impedance amplitude of that branch tends towards its maximum value, it remains relatively constant compared to the stray capacitance to ground. After parallel connection, the equivalent impedance The amplitude will not reach its maximum value, where, This is the equivalent impedance of the branch where the transformer is located. The equivalent impedance of the branch where the damper is located. The equivalent impedance to ground stray capacitance is represented by " / / ". " / / " indicates parallel connection.

[0058] in, ,

[0059] Optionally, when the branch containing the compensating reactor experiences parallel resonance, the equivalent impedance of that branch tends to its maximum value, and the subsequent branches (including the load-side branches) receive a minimum voltage, which is represented by a minimum point on the amplitude-frequency curve. Similarly, when the branch containing the transformer experiences parallel resonance, the equivalent impedance of that branch tends to its maximum value, and the load-side branches receive a minimum voltage, which is represented by another minimum point on the amplitude-frequency curve. Therefore, the minimum frequency on the CVT amplitude-frequency curve can be considered to be approximately the frequency at which the branches containing the compensating reactor and the transformer respectively experience parallel resonance. The maximum point in the amplitude-frequency characteristic curve is generated by the series resonance of the entire circuit considering stray capacitance.

[0060] Optionally, due to the presence of stray capacitance, the CVT has multiple resonant frequencies, for example, such as Figure 3 The figure shows the frequency response characteristic curve (specifically the amplitude-frequency response curve) of the equivalent circuit model in the embodiment of this application, including two parallel resonant frequencies f. min_1 and f min_2 (Right now and ) and two series resonant frequencies f max_1 and f max_2 (Right now and ).

[0061] Optionally, the minimum and maximum values ​​can be determined from the frequency response characteristic curve. Since these minimum and maximum values ​​are related to the parameters of stray capacitance, the stray parameters of the capacitive voltage transformer can be determined based on the equivalent circuit model and the minimum and maximum values.

[0062] Optionally, the stray parameters of the capacitive voltage transformer may include the capacitance value of the first stray capacitor, the capacitance value of the second stray capacitor, the capacitance value of the stray capacitor to ground, and the capacitance value of the third stray capacitor.

[0063] In one possible implementation, a pre-trained parameter determination model can be obtained, and then the maximum and minimum values ​​can be used as inputs. The parameter determination model can output the stray parameters of the capacitive voltage transformer. The parameter determination model can be implemented based on a neural network model. The parameter determination model can be applicable to the equivalent circuit model provided in the embodiments of this application, or it can be a general model applicable to any equivalent circuit model.

[0064] In another possible implementation, a data calculation model can be obtained to calculate the stray parameters of the capacitive voltage transformer based on the maximum and minimum values.

[0065] The aforementioned method for determining stray parameters first involves applying a unit pulse voltage excitation to a capacitive voltage transformer (CVT) and determining its frequency response characteristic curve. Then, an equivalent circuit model of the CVT is obtained. Finally, the stray parameters of the CVT are determined based on the minimum and maximum values ​​in the equivalent circuit model and the frequency response characteristic curve. This method effectively improves the accuracy of determining CVT stray capacitance parameters by determining the CVT's frequency response characteristic curve, identifying the CVT's resonant point based on the curve, and then using the equivalent circuit model to determine the stray capacitance parameters. Furthermore, this method allows for non-destructive measurement of CVT stray parameters, eliminating the need for precision measuring instruments. This allows for routine factory testing of CVT products, facilitating quality control for manufacturers and enabling users to calculate and evaluate the CVT's structure and operating characteristics according to their specific needs.

[0066] In one exemplary embodiment, such as Figure 4 As shown, optionally, the stray parameters of the capacitive voltage transformer are determined based on the minimum and maximum values ​​in the equivalent circuit model and frequency response characteristic curve, including steps 401 to 402. Wherein:

[0067] S401, determine the stray parameters of the first stray capacitance and the second stray capacitance based on the minimum value in the frequency response characteristic curve.

[0068] Optionally, the stray parameters of the first stray capacitor and the second stray capacitor may include the capacitance value of the first stray capacitor and the capacitance value of the second stray capacitor.

[0069] Optionally, based on the analysis of the equivalent circuit model, the minimum values ​​in the frequency response characteristic curve correspond to the resonant points when the branch containing the compensating reactor and the branch containing the transformer experience parallel resonance, respectively. Therefore, the stray parameters of the first and second stray capacitors can be determined based on the minimum values.

[0070] Optionally, as can be seen from the equivalent circuit model, when parallel resonance occurs in the branch where the compensating reactor is located, the parallel resonance frequency is... This can be expressed by the following formula:

[0071]

[0072] When parallel resonance occurs in the branch where the transformer is located, the parallel resonant frequency is... This can be expressed by the following formula:

[0073]

[0074] Optionally, after determining the minimum value through the frequency response characteristic curve, the stray parameters of the first stray capacitance and the second stray capacitance can be determined through the above characteristics.

[0075] S402, determine the stray parameters of the third stray capacitor and the stray capacitor to ground based on the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitor and the second stray capacitor.

[0076] Optionally, since the maximum value in the frequency response characteristic curve is generated by the series resonance of the circuit as a whole considering stray capacitance, and the series resonance frequency is difficult to solve analytically, the stray parameters of the third stray capacitance and the stray capacitance to ground can be determined based on the maximum value and the stray parameters of the first and second stray capacitances, provided that the stray parameters of the first and second stray capacitances have been obtained.

[0077] Optional, such as Figure 5 As shown, the spurious parameters of the third spurious capacitor and the spurious capacitor to ground are determined based on the maximum value in the frequency response characteristic curve and the spurious parameters of the first and second spurious capacitors, including the following steps 501 to 502. Wherein:

[0078] S501, obtain the target function.

[0079] The objective function can be the frequency response characteristic expression of the equivalent circuit model, which is determined by the maxima, minima, and various spurious parameters.

[0080] Optionally, the frequency response characteristic expression in the equivalent circuit model can be as follows:

[0081]

[0082] in, To compensate for the equivalent impedance of the branch where the reactor is located, .

[0083] Optionally, the equivalent impedance of the branch where the compensating reactor is located is determined. hour, The value is one of the minimum values. In determining the equivalent impedance of the branch where the transformer is located hour, The value is another of the minimum values. Determine the equivalent impedance of the branch where the damper is located. Equivalent impedance of the branch containing the stray capacitance to ground hour, The value can be any of the maxima. or .

[0084] S502, determine the maximum value of the objective function according to the preset optimization algorithm, and determine the stray parameters of the third stray capacitor and the stray capacitor to ground according to the maximum value.

[0085] Optionally, the stray parameters of the third stray capacitance and the stray capacitance to ground can be optimally estimated by solving the following equation, thereby determining the stray parameters of the third stray capacitance and the stray capacitance to ground.

[0086]

[0087] in, These are the optimal estimates of the stray parameters for the third stray capacitance and the stray capacitance to ground, respectively.

[0088] In one possible implementation, such as Figure 6 As shown, the maximum value of the objective function is determined according to a preset optimization algorithm, and the stray parameters of the third stray capacitance and the stray capacitance to ground are determined based on the maximum value, including the following steps 601 to 603. Wherein:

[0089] S601, obtain the initial stray parameters of the third stray capacitance and the stray capacitance to ground.

[0090] Optional, initial stray parameters of the third stray capacitance and initial stray parameters of stray capacitance to ground It can be a standard value given by the manufacturer before the product leaves the factory.

[0091] S602, determine the search range according to each initial stray parameter, and determine multiple sets of parameter combinations according to each search range.

[0092] The parameter combination includes candidate stray parameters for the third stray capacitor and candidate stray parameters for the ground stray capacitor.

[0093] Optionally, the search range corresponding to the third stray capacitor can be determined based on the initial stray parameters of the third stray capacitor. ±50% determines the first search range, i.e., [0.5]. 1.5 The search range can be expanded or narrowed according to the actual situation. This application embodiment does not limit the size of the search range.

[0094] Similarly, it can be based on the initial spurious parameters The ±50% determines the second search range, i.e., [0.5]. 1.5 The search range can be expanded or narrowed according to the actual situation. This application embodiment does not limit the size of the search range.

[0095] Optionally, n items can be determined in the first search range. The candidate values ​​are determined in the second search range, with n values ​​selected from each candidate value. Candidate values, based on n candidate values ​​and n The candidate values ​​form an n×n grid, and each grid can include a set of parameter combinations. The size of n, i.e. the number of grids (accuracy), can be flexibly set according to the actual situation.

[0096] S603 calculates the objective function based on the combination of parameters. When the objective function reaches its maximum value, the stray parameters of the third stray capacitor and the stray capacitor to ground are determined based on the combination of parameters.

[0097] Optionally, for each set of parameter combinations Candidate values ​​and Candidate values ​​are used to determine the value of the objective function, i.e., to solve the expression for the frequency response characteristics. When |H| reaches its maximum value, the corresponding candidate value is used as the stray parameter for the third stray capacitance and the stray capacitance to ground.

[0098] It is understandable that when the frequency response curve has two or more maxima, the equivalent impedance of the branch containing the damper in the calculation of H will be affected. Equivalent impedance of the branch containing the stray capacitance to ground hour, The value of can be any of the maxima; for example, there are two maxima. At that time, based on The maximum value of the determined objective function and based on The maximum value of the determined objective function may differ, but based on The maximum value of the determined objective function is the corresponding and , and based on The maximum value of the determined objective function is the corresponding and They are the same, therefore, the maximum value can be used to mutually verify the determined result.

[0099] In another possible implementation, the spurious parameters of the third spurious capacitance and the ground spurious capacitance that satisfy the maximum value of the objective function can be determined by optimization algorithms such as genetic algorithms, particle swarm optimization, or ant colony optimization. It can be understood that the capacitance values ​​of the third spurious capacitance and the ground spurious capacitance corresponding to the maximum value of the objective function can be used as spurious parameters.

[0100] In one exemplary embodiment, such as Figure 7As shown, optionally, the minimum values ​​in the frequency response characteristic curve include a first minimum value and a second minimum value. Determining the stray parameters of the first and second stray capacitances based on the minimum values ​​in the frequency response characteristic curve includes steps 701 to 702. Wherein:

[0101] S701, determine the stray parameters of the first stray capacitor based on the first minimum value, the inductance of the compensation reactor coil, and the resistance of the compensation reactor coil.

[0102] S702, determine the stray parameters of the second stray capacitor based on the second minimum value, winding inductance, and winding resistance.

[0103] Optionally, after determining the first and second minimum values ​​in the frequency response characteristic curve, the stray parameters of the first stray capacitance can be determined according to the following formula. The stray parameters of the second stray capacitance :

[0104]

[0105]

[0106] in, This is the first minimum value. This is the second minimum value.

[0107] As an optional implementation method, such as Figure 8 As shown, the spurious parameter determination method provided in this application embodiment may include the following specific steps:

[0108] S801 applies a unit pulse voltage excitation to a capacitive voltage transformer and determines the frequency response characteristic curve of the capacitive voltage transformer.

[0109] S802, obtain the equivalent circuit model of the capacitive voltage transformer.

[0110] The equivalent circuit model of a capacitive voltage transformer includes voltage divider capacitors, compensating reactors, transformers, and dampers;

[0111] The compensating reactor includes the inductance of the compensating reactor coil, the resistance of the compensating reactor coil, and a first stray capacitance. The inductance and resistance of the compensating reactor coil are connected in series to form a first series branch. The first series branch is connected in parallel with the first stray capacitance. The first end of the first series branch is connected in series with a voltage divider capacitor.

[0112] A transformer includes a winding inductance, a winding resistance, a stray capacitance to ground, and a second stray capacitance. The winding inductance and the winding resistance are connected in series to form a second series branch. The second series branch is connected in parallel with the second stray capacitance. The first end of the second series branch is connected to the second end of the first series branch and the first end of the stray capacitance to ground.

[0113] The damper includes a damping inductor, a damping resistor, and a third stray capacitor. The damping inductor and the damping resistor are connected in series to form a third series branch. The third series branch is connected in parallel with the third stray capacitor. The first end of the third series branch is connected to the second end of the second series branch, and the second end of the third series branch is connected to the second end of the stray capacitor to ground.

[0114] S803 determines the stray parameters of the first stray capacitor based on the first minimum value in the frequency response characteristic curve, the inductance of the compensation reactor coil, and the resistance of the compensation reactor coil.

[0115] S804 determines the stray parameters of the second stray capacitance based on the second minimum value in the frequency response characteristic curve, the winding inductance, and the winding resistance.

[0116] S805, obtain the target function.

[0117] The objective function can be the frequency response characteristic expression of the equivalent circuit model, which is determined by the maxima, minima, and various spurious parameters.

[0118] S806, obtain the initial stray parameters of the third stray capacitance and the stray capacitance to ground.

[0119] S807 determines the search range based on each initial stray parameter, and determines multiple sets of parameter combinations based on each search range.

[0120] The parameter combination includes candidate stray parameters for the third stray capacitor and candidate stray parameters for the ground stray capacitor.

[0121] S808 calculates the objective function based on the combination of parameters. When the objective function reaches its maximum value, it determines the stray parameters of the third stray capacitor and the stray capacitor to ground based on the combination of parameters.

[0122] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0123] For example, a CVT frequency response characteristic testing system can be built by combining PSCAD and MATLAB simulation platforms. A pulse voltage is applied to the primary side of the CVT, and the line voltage and the measured voltage on the secondary side of the CVT are recorded simultaneously. The resulting amplitude-frequency characteristic curve of the CVT is shown in the figure. Figure 9 As shown, the amplitude-frequency response curve at f max_1 =441Hz and f max_2 It has a maximum value at =2200Hz, while at f min_1 =510Hz and f min_2 It has a minimum value at 8657 Hz.

[0124] According to f min_1 and f min_2 Calculate the capacitance value C of the first stray capacitor. k The capacitance value C of the second stray capacitor ps Then according to C p and C s The standard value (all 100pF) was used to determine the search range, and a 500×500 grid was divided. Based on the calculated C... k and C ps Using f max_1 and f max_2 Calculate |H| for each grid cell separately, such as Figure 10 As shown, |H| reaches its maximum value of 184439 × 10 at grid coordinates (247, 269). 5 The parameter combination in this grid is determined as the capacitance value of the stray capacitance to ground. The capacitance value C of the third stray capacitor s The corresponding spurious parameters and relative errors are shown in Table 1. The spurious parameter determination method proposed in this application has an estimation error of no more than 4% for spurious capacitance and can accurately calculate the spurious parameters of the CVT based on the frequency response characteristics of the CVT.

[0125] Table 1

[0126] Stray capacitance True value (pF) Calculated value (pF) Relative error (%) <![CDATA[C k ]]> 600 601.1506 0.1900 <![CDATA[C ps ]]> 6 6.0002 0.0033 <![CDATA[C p ]]> 100 99.2000 -0.8000 <![CDATA[C s ]]> 100 103.6000 3.600

[0127] Based on the same inventive concept, this application also provides a spurious parameter determination apparatus for implementing the spurious parameter determination method described above. The solution provided by this apparatus is similar to the implementation scheme described in the above method; therefore, the specific limitations in one or more spurious parameter determination apparatus embodiments provided below can be found in the limitations of the spurious parameter determination method described above, and will not be repeated here.

[0128] In one exemplary embodiment, such as Figure 11 As shown, a stray parameter determination device 1100 is provided, comprising: a first acquisition module 1101, a second acquisition module 1102, and a determination module 11103, wherein:

[0129] The first acquisition module 1101 is used to apply a unit pulse voltage excitation to the capacitive voltage transformer and determine the frequency response characteristic curve of the capacitive voltage transformer.

[0130] The second acquisition module 1102 is used to acquire the equivalent circuit model of the capacitive voltage transformer;

[0131] The determination module 1103 is used to determine the stray parameters of the capacitive voltage transformer based on the minimum and maximum values ​​in the equivalent circuit model and frequency response characteristic curve.

[0132] In an exemplary embodiment, the equivalent circuit model of the capacitive voltage transformer includes a voltage divider capacitor, a compensating reactor, a transformer, and a damper. The compensating reactor includes the inductance of the compensating reactor coil, the resistance of the compensating reactor coil, and a first stray capacitance. The inductance and resistance of the compensating reactor coil are connected in series to form a first series branch. The first series branch is connected in parallel with the first stray capacitance, and the first end of the first series branch is connected in series with the voltage divider capacitor. The transformer includes winding inductance, winding resistance, stray capacitance to ground, and a second stray capacitance. The winding inductance and winding resistance are connected in series to form a second series branch. The second series branch is connected in parallel with the second stray capacitor. The first end of the second series branch is connected to the second end of the first series branch and the first end of the stray capacitor to ground. The damper includes a damping inductor, a damping resistor and a third stray capacitor. The damping inductor and damping resistor are connected in series to form a third series branch. The third series branch is connected in parallel with the third stray capacitor. The first end of the third series branch is connected to the second end of the second series branch and the second end of the third series branch is connected to the second end of the stray capacitor to ground.

[0133] In an exemplary embodiment, the determining module 1103 is specifically configured to determine the stray parameters of the first stray capacitor and the second stray capacitor based on the minimum value in the frequency response characteristic curve; and to determine the stray parameters of the third stray capacitor and the stray capacitor to ground based on the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitor and the second stray capacitor.

[0134] In an exemplary embodiment, the determining module 1103 is specifically used to obtain the objective function, which may be the frequency response characteristic expression of the equivalent circuit model. The frequency response characteristic expression is determined by the maximum value, the minimum value, and each spurious parameter. The maximum value of the objective function is determined according to a preset optimization algorithm, and the spurious parameters of the third spurious capacitor and the spurious capacitor to ground are determined according to the maximum value.

[0135] In an exemplary embodiment, the determining module 1103 is specifically used to obtain the initial spurious parameters of the third spurious capacitance and the ground spurious capacitance; determine the search range according to each initial spurious parameter, and determine multiple sets of parameter combinations according to each search range, the parameter combinations including candidate spurious parameters of the third spurious capacitance and candidate spurious parameters of the ground spurious capacitance; calculate the objective function according to each parameter combination, and when the objective function reaches its maximum value, determine the spurious parameters of the third spurious capacitance and the ground spurious capacitance according to the parameter combination.

[0136] In an exemplary embodiment, the minimum value in the frequency response characteristic curve includes a first minimum value and a second minimum value. The determining module 1103 is specifically used to determine the stray parameters of the first stray capacitor based on the first minimum value, the inductance of the compensating reactor coil, and the resistance of the compensating reactor coil; and to determine the stray parameters of the second stray capacitor based on the second minimum value, the winding inductance, and the winding resistance.

[0137] Each module in the aforementioned stray parameter determination device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0138] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 12As shown, this computer device includes a processor, memory, input / output interfaces (I / O), 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 the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When executed by the processor, the computer program implements a method for determining spurious parameters.

[0139] Those skilled in the art will understand that Figure 12 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.

[0140] 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 described in any of the above method embodiments.

[0141] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps described in any of the above method embodiments.

[0142] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps described in any of the above method embodiments.

[0143] Those skilled in the art will understand that all or part of the processes in the methods of 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 of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory 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 (ReRAM), 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). 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, artificial intelligence (AI) processors, etc., and are not limited to these.

[0144] 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 application.

[0145] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. 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 application should be determined by the appended claims.

Claims

1. A method for determining stray parameters, characterized in that, The method includes: A unit pulse voltage excitation is applied to a capacitive voltage transformer, and the frequency response characteristic curve of the capacitive voltage transformer is determined. Obtain the equivalent circuit model of the capacitive voltage transformer; Based on the equivalent circuit model and the minimum and maximum values ​​in the frequency response characteristic curve, the stray parameters of the capacitive voltage transformer are determined. The equivalent circuit model of the capacitive voltage transformer includes a voltage divider capacitor, a compensating reactor, a transformer, and a damper. The compensating reactor includes the inductance of the compensating reactor coil, the resistance of the compensating reactor coil, and a first stray capacitance. The inductance and resistance of the compensating reactor coil are connected in series to form a first series branch. The first series branch is connected in parallel with the first stray capacitance. The first end of the first series branch is connected in series with the voltage divider capacitor. The transformer includes a winding inductance, a winding resistance, a stray capacitance to ground, and a second stray capacitance. The winding inductance and the winding resistance are connected in series to form a second series branch. The second series branch is connected in parallel with the second stray capacitance. The first end of the second series branch is connected to the second end of the first series branch and the first end of the stray capacitance to ground. The damper includes a damping inductor, a damping resistor, and a third stray capacitor. The damping inductor and the damping resistor are connected in series to form a third series branch. The third series branch is connected in parallel with the third stray capacitor. The first end of the third series branch is connected to the second end of the second series branch, and the second end of the third series branch is connected to the second end of the stray capacitor to ground.

2. The method according to claim 1, characterized in that, The step of determining the stray parameters of the capacitive voltage transformer based on the minimum and maximum values ​​in the equivalent circuit model and the frequency response characteristic curve includes: The stray parameters of the first stray capacitance and the second stray capacitance are determined based on the minimum values ​​in the frequency response characteristic curve. The stray parameters of the third stray capacitor and the stray capacitor to ground are determined based on the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitor and the second stray capacitor.

3. The method according to claim 2, characterized in that, The step of determining the stray parameters of the third stray capacitor and the ground stray capacitor based on the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitor and the second stray capacitor includes: Obtain the objective function, which may be the frequency response characteristic expression of the equivalent circuit model, and the frequency response characteristic expression is determined by the maximum value, the minimum value and each of the spurious parameters; The maximum value of the objective function is determined according to a preset optimization algorithm, and the stray parameters of the third stray capacitor and the stray capacitor to ground are determined according to the maximum value.

4. The method according to claim 3, characterized in that, The step of determining the maximum value of the objective function according to a preset optimization algorithm, and determining the stray parameters of the third stray capacitance and the stray capacitance to ground according to the maximum value, includes: Obtain the initial stray parameters of the third stray capacitor and the ground stray capacitor; The search range is determined according to each of the initial stray parameters, and multiple sets of parameter combinations are determined according to each of the search ranges. The parameter combinations include the candidate stray parameters of the third stray capacitor and the candidate stray parameters of the ground stray capacitor. The objective function is calculated based on each of the parameter combinations. When the objective function reaches its maximum value, the stray parameters of the third stray capacitor and the stray capacitor to ground are determined based on the parameter combinations.

5. The method according to claim 2, characterized in that, The minimum values ​​in the frequency response characteristic curve include a first minimum value and a second minimum value. Determining the stray parameters of the first stray capacitance and the second stray capacitance based on the minimum values ​​in the frequency response characteristic curve includes: The stray parameters of the first stray capacitor are determined based on the first minimum value, the inductance of the compensation reactor coil, and the resistance of the compensation reactor coil. The stray parameters of the second stray capacitance are determined based on the second minimum value, the winding inductance, and the winding resistance.

6. A stray parameter determination device, characterized in that, The device includes: The first acquisition module is used to apply a unit pulse voltage excitation to the capacitive voltage transformer and determine the frequency response characteristic curve of the capacitive voltage transformer. The second acquisition module is used to acquire the equivalent circuit model of the capacitive voltage transformer; The determination module is used to determine the stray parameters of the capacitive voltage transformer based on the minimum and maximum values ​​in the equivalent circuit model and the frequency response characteristic curve. The equivalent circuit model of the capacitive voltage transformer includes a voltage divider capacitor, a compensating reactor, a transformer, and a damper. The compensating reactor includes the inductance of the compensating reactor coil, the resistance of the compensating reactor coil, and a first stray capacitance. The inductance and resistance of the compensating reactor coil are connected in series to form a first series branch. The first series branch is connected in parallel with the first stray capacitance. The first end of the first series branch is connected in series with the voltage divider capacitor. The transformer includes a winding inductance, a winding resistance, a stray capacitance to ground, and a second stray capacitance. The winding inductance and the winding resistance are connected in series to form a second series branch. The second series branch is connected in parallel with the second stray capacitance. The first end of the second series branch is connected to the second end of the first series branch and the first end of the stray capacitance to ground. The damper includes a damping inductor, a damping resistor, and a third stray capacitor. The damping inductor and the damping resistor are connected in series to form a third series branch. The third series branch is connected in parallel with the third stray capacitor. The first end of the third series branch is connected to the second end of the second series branch, and the second end of the third series branch is connected to the second end of the stray capacitor to ground.

7. The apparatus according to claim 6, characterized in that, The determining module is specifically used to determine the stray parameters of the first stray capacitor and the second stray capacitor based on the minimum value in the frequency response characteristic curve; and to determine the stray parameters of the third stray capacitor and the stray capacitor to ground based on the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitor and the second stray capacitor.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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