Stray parameter determination method and device, equipment, storage medium and program product

Abstract

The invention relates to a stray parameter determination method and device, equipment, a storage medium and a program product. The method comprises the following steps: applying unit pulse voltage excitation to the capacitor voltage transformer, and determining a frequency response characteristic curve of the capacitor voltage transformer; obtaining an equivalent circuit model of the capacitor voltage transformer; and according to the minimum value and the maximum value in the equivalent circuit model and the frequency response characteristic curve, determining stray parameters of the capacitor voltage transformer. By adopting the method, the stray parameters can be accurately determined.

Description

Technical Field

[0001] The present application relates to the technical field of capacitive voltage transformers, and in particular to a method, device, equipment, storage medium and program product for determining stray parameters. Background Art

[0002] The stray capacitance in the Capacitor Voltage Transformer (CVT) is caused by factors such as its circuit layout, the physical position relationship between components, and the external environment. These capacitances are not clearly planned or expected at the beginning of the CVT design, but are naturally formed with the actual construction of the circuit and the influence of the external environment. The stray capacitance will significantly affect the performance of the CVT.

[0003] Currently, the parameters of CVT stray capacitance are determined with low accuracy. Summary of the invention

[0004] Based on this, it is necessary to provide a stray parameter determination method, device, equipment, storage medium and program product that can improve the accuracy of determining the stray capacitance parameters of a capacitive voltage transformer in response to the above technical problems.

[0005] In a first aspect, the present application provides a method for determining a spurious parameter, comprising:

[0006] Applying unit pulse voltage excitation to the capacitor voltage transformer and determining a frequency response characteristic curve of the capacitor voltage transformer;

[0007] Obtaining an equivalent circuit model of a capacitive voltage transformer;

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

[0009] In one embodiment, the equivalent circuit model of the capacitive voltage transformer includes a voltage-dividing 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 the first stray capacitance, the inductance of the compensating reactor coil and the 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-dividing 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, and 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 capacitance, 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 capacitance, 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 capacitance to ground.

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

[0011] In one of the embodiments, determining the stray parameters of the third stray capacitance and the stray capacitance to ground according to the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitance and the second stray capacitance includes: obtaining a target function, which may be a frequency response characteristic expression of an equivalent circuit model, wherein the frequency response characteristic expression is determined by the maximum value, the minimum value, and the stray parameters; determining the maximum value of the target 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.

[0012] In one of the embodiments, determining a maximum value of an objective function according to a preset optimization algorithm, and determining stray parameters of a third stray capacitance and a stray capacitance to ground according to the maximum value, includes: obtaining initial stray parameters of the third stray capacitance and the stray capacitance to ground; determining a search range according to each initial stray parameter, and determining a plurality of groups of parameter combinations according to each search range, the parameter combination including candidate stray parameters of the third stray capacitance and candidate stray parameters of the stray capacitance; calculating an objective function according to each parameter combination, and determining the stray parameters of the third stray capacitance and the stray capacitance to ground according to the parameter combination when the objective function obtains a maximum value.

[0013] In one of the embodiments, the minimum value in the frequency response characteristic curve includes a first minimum value and a second minimum value, and the stray parameters of the first stray capacitance and the second stray capacitance are determined according to the minimum value in the frequency response characteristic curve, including: determining the stray parameters of the first stray capacitance according to the first minimum value, the inductance of the compensation reactor coil, and the resistance of the compensation reactor coil; determining the stray parameters of the second stray capacitance according to the second minimum value, the winding inductance, and the winding resistance.

[0014] In a second aspect, the present application also provides a spurious parameter determination device, comprising:

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

[0016] A second acquisition module is used to acquire an equivalent circuit model of a capacitive voltage transformer;

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

[0018] In one embodiment, the equivalent circuit model of the capacitive voltage transformer includes a voltage-dividing 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 the first stray capacitance, the inductance of the compensating reactor coil and the 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-dividing 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, and 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 capacitance, 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 capacitance, 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 capacitance to ground.

[0019] In one embodiment, the determination module is specifically used to determine the stray parameters of the first stray capacitance and the second stray capacitance according to the minimum value in the frequency response characteristic curve; determine the stray parameters of the third stray capacitance and the stray capacitance to ground according to the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitance and the second stray capacitance.

[0020] In one of the embodiments, the determination module is specifically used to obtain the objective function, which can be a 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 various stray parameters; 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 according to the maximum value.

[0021] In one of the embodiments, the determination module is specifically used to obtain initial stray parameters of the third stray capacitance and the stray capacitance to ground; determine a search range according to each initial stray parameter, and determine multiple groups of parameter combinations according to each search range, the parameter combination including candidate stray parameters of the third stray capacitance and candidate stray parameters of the stray capacitance; calculate the objective function according to each parameter combination, and when the objective function obtains a maximum value, determine the stray parameters of the third stray capacitance and the stray capacitance to ground according to the parameter combination.

[0022] In one embodiment, the minimum value in the frequency response characteristic curve includes a first minimum value and a second minimum value, and the determination module is specifically used to determine the stray parameters of the first stray capacitance according to the first minimum value, the inductance of the compensation reactor coil, and the resistance of the compensation reactor coil; and determine the stray parameters of the second stray capacitance according to the second minimum value, the winding inductance, and the winding resistance.

[0023] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, any of the methods described in the first aspect is implemented.

[0024] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements any of the methods described in the first aspect above.

[0025] In a fifth aspect, the present application further provides a computer program product, including a computer program, which, when executed by a processor, implements any of the methods described in the first aspect above.

[0026] The above-mentioned stray parameter determination method, device, equipment, storage medium and program product first apply unit pulse voltage excitation to the capacitor voltage transformer and determine the frequency response characteristic curve of the capacitor voltage transformer, then obtain the equivalent circuit model of the capacitor voltage transformer, and then determine the stray parameters of the capacitor voltage transformer according to 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 capacitor voltage transformer, and then determining the resonance point of the CVT according to the frequency response characteristic curve, and then determining the capacitance parameters of the stray capacitance in combination with the equivalent circuit model, the accuracy of determining the stray capacitance parameters of the CVT can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic diagram of a flow chart of a method for determining a stray parameter in an embodiment;

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

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

[0031] Figure 4 A schematic diagram of a flow chart of a step of determining stray parameters of a capacitor voltage transformer in one embodiment;

[0032] Figure 5 It is a schematic flow chart of a step of determining stray parameters of a third stray capacitance and a stray capacitance to ground in one embodiment;

[0033] Figure 6 It is a schematic flow chart of a step of determining stray parameters of a third stray capacitance and a stray capacitance to ground in another embodiment;

[0034] Figure 7 A schematic diagram of a flow chart of a step of determining stray parameters of a first stray capacitance and a second stray capacitance in one embodiment;

[0035] Figure 8 is a flow chart of a method for determining stray parameters in another embodiment;

[0036] Fig. 9 A schematic diagram of an amplitude-frequency characteristic curve of a capacitive voltage transformer determined in an embodiment;

[0037] Fig.10 It is a schematic diagram of the result of determining the stray parameters of the third stray capacitance and the stray capacitance to ground in one embodiment;

[0038] Fig.11 is a structural block diagram of a device for determining a spurious parameter in one embodiment;

[0039] Fig.12 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0041] The stray capacitance in the Capacitor Voltage Transformer (CVT) is caused by factors such as its circuit layout, the physical position relationship between components, and the external environment. These capacitances are not clearly planned or expected at the beginning of the CVT design, but are naturally formed with the actual construction of the circuit and the influence of the external environment. The stray capacitance will significantly affect the performance of the CVT.

[0042] Currently, the parameters of CVT stray capacitance are determined with low accuracy.

[0043] In view of this, the present application provides a stray parameter determination method that can accurately determine the parameters of stray capacitance. The stray parameter determination method provided in the embodiment of the present application, its execution subject can be a stray parameter determination device, and the stray parameter determination device can be implemented by software, hardware, or a combination of software and hardware. It can be embedded in or independent of the processor in the computer device in the form of hardware, or it can be stored in the memory of the computer device in the form of software. In the following method embodiments, the execution subject is a computer device as an example for explanation, wherein the computer device can be a server or a desktop computer, and the embodiment of the present application does not limit the specific type of the computer device.

[0044] In an exemplary embodiment, Figure 1 As shown, a method for determining a spurious parameter is provided, comprising the following steps 101 to 103. Among them:

[0045] S101, applying a unit pulse voltage excitation to a capacitor voltage transformer, and determining a frequency response characteristic curve of the capacitor 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, the capacitor voltage transformer is a high-voltage measuring device used in power systems, and the saturation voltage of the capacitor voltage transformer may be the maximum voltage value that 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 stimulated to generate a response in a wide frequency domain, and the pulse response of the secondary side of the CVT can be synchronously collected by an acquisition device, and the collected pulse response is sent to a computer device, so that the computer device determines the frequency response characteristic curve of the capacitive voltage transformer according to the unit pulse voltage excitation and the pulse response, which can be specifically determined according to the following formula:

[0049]

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

[0051] Optionally, the primary side of the capacitive voltage transformer may be an input end, the secondary side may be an output end, and the acquisition device may be an ordinary oscilloscope or a recorder, etc.

[0052] S102, obtaining an equivalent circuit model of a capacitive voltage transformer.

[0053] Optional, such as Figure 2 As shown, the equivalent circuit model of the capacitive voltage transformer in the embodiment of the present application includes a voltage divider capacitor , compensating reactors, transformers and dampers; compensating reactors, including the inductance of compensating reactor coils , Compensation reactor coil resistance and the first stray capacitance , compensating the inductance of the reactor coil and the resistance of the compensation 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 and the voltage divider capacitor Series; transformer, including winding inductance , Winding resistance , stray capacitance to ground and the second stray capacitance , winding inductance and winding resistance series to form a second series branch, the second series branch and the second stray capacitor In parallel, the first end of the second series branch is connected to the second end of the first series branch and the stray capacitance to ground The first ends of the two resistors are connected; a damper including a damping inductor , Damping resistor and third stray capacitance , damping inductance and damping resistor are connected in series to form a third series branch, the third series branch and 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 stray capacitance to ground. The second end of the connection.

[0054] In another possible implementation manner, the equivalent circuit model may also be other existing models.

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

[0056] S103, determining the stray parameters of the capacitive voltage transformer according to the equivalent circuit model and the minimum value and the maximum value in the frequency response characteristic curve.

[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 primary side stray capacitance to ground Therefore, when the branch where the damper is located undergoes parallel resonance, although the equivalent impedance amplitude of the branch tends to its maximum value, it is still the same as the stray capacitance to ground. After parallel connection, the equivalent impedance The amplitude of will not reach the maximum value, among which, is the equivalent impedance of the branch where the transformer is located, is the equivalent impedance of the branch where the damper is located, is the equivalent impedance of the stray capacitance to ground, and “ / / ” indicates parallel connection.

[0058] in, ,

[0059] Optionally, when the branch where the compensating inductor is located undergoes parallel resonance, the equivalent impedance of the branch where the compensating inductor is located tends to a maximum value, and the subsequent branches (including the load side branch) as a whole obtain a minimum voltage, which is manifested as a minimum point on the amplitude-frequency curve; similarly, when the branch where the transformer is located undergoes parallel resonance, the equivalent impedance of the branch where the transformer is located tends to a maximum value, and the load side branch obtains a minimum voltage, which is manifested as another minimum point on the amplitude-frequency curve. Therefore, it can be considered that the minimum frequency on the CVT amplitude-frequency curve is approximately the frequency when the branch where the compensating inductor is located and the branch where the transformer is located respectively undergo parallel resonance; and the maximum point in the amplitude-frequency characteristic curve is generated by the series resonance of the circuit as a whole considering the stray capacitance.

[0060] Optionally, due to the presence of stray capacitance, the CVT has multiple resonant frequencies, for example Figure 3 As shown, the frequency response characteristic curve (specifically, the amplitude-frequency characteristic response curve) of the equivalent circuit model in the embodiment of the present application includes two parallel resonant frequencies f min_1 and f min_2 (Right now and ) and 2 series resonant frequencies f max_1 and f max_2 (Right now and ).

[0061] Optionally, the minimum and maximum values ​​may be determined from the frequency response characteristic curve. Since the maximum and minimum values ​​are related to the parameters of the stray capacitance, the stray parameters of the capacitive voltage transformer may 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 a capacitance value of a first stray capacitor, a capacitance value of a second stray capacitor, a capacitance value of a stray capacitor to ground, and a capacitance value of a third stray capacitor.

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

[0064] In another possible implementation, a data calculation model may be obtained to calculate the stray parameters of the capacitive voltage transformer according to the maximum value and the minimum value.

[0065] The above-mentioned stray parameter determination method first applies a unit pulse voltage excitation to the capacitive voltage transformer and determines the frequency response characteristic curve of the capacitive voltage transformer, then obtains the equivalent circuit model of the capacitive voltage transformer, and then determines the stray parameters of the capacitive voltage transformer according to 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 capacitive voltage transformer, and then determining the resonance point of the CVT according to the frequency response characteristic curve, and then determining the capacitance parameters of the stray capacitance in combination with the equivalent circuit model, the accuracy of determining the stray capacitance parameters of the CVT can be effectively improved. In addition, the above-mentioned method can realize non-destructive measurement of CVT stray parameters, and does not require precision measuring instruments in the process. In this way, the method can be used to perform routine tests on the factory delivery of CVT products, which is beneficial to the manufacturer's control of product quality, and is also convenient for users to calculate and evaluate the CVT product structure and working characteristics in combination with their actual needs.

[0066] In an exemplary embodiment, Figure 4 As shown, optionally, determining the stray parameters of the capacitive voltage transformer according to the equivalent circuit model and the minimum and maximum values ​​in the frequency response characteristic curve includes the following steps 401 to 402. Wherein:

[0067] S401, determining stray parameters of a first stray capacitance and a second stray capacitance according to a minimum value in a frequency response characteristic curve.

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

[0069] Optionally, according to the analysis of the equivalent circuit model, the frequencies corresponding to the minimum values ​​in the frequency response characteristic curve are the resonance points when parallel resonance occurs in the branch where the compensation inductor is located and the resonance points when parallel resonance occurs in the branch where the transformer is located. Therefore, the stray parameters of the first stray capacitance and the second stray capacitance can be determined according to the minimum values.

[0070] Optionally, it can be known from the equivalent circuit model that when parallel resonance occurs in the branch where the compensation reactor is located, the parallel resonance frequency It can be expressed by the following formula:

[0071]

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

[0073]

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

[0075] S402, determining stray parameters of a third stray capacitance and a stray capacitance to ground according to a maximum value in a frequency response characteristic curve and stray parameters of the first stray capacitance and the second stray capacitance.

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

[0077] Optional, such as Figure 5 As shown, the stray parameters of the third stray capacitance and the stray capacitance to ground are determined according to the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitance and the second stray capacitance, including the following steps 501 to 502. Among them:

[0078] S501, obtaining the objective function.

[0079] The objective function may be a frequency response characteristic expression of an equivalent circuit model, and the frequency response characteristic expression is determined by a maximum value, a minimum value and various spurious parameters.

[0080] Alternatively, 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, when determining the equivalent impedance of the branch where the compensation reactor is located 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 of is another one of the minimum values , in determining the equivalent impedance of the branch where the damper is located The equivalent impedance of the branch where the stray capacitance to ground is located hour, The value can be any of the maximum values or .

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

[0085] Optionally, the stray parameters of the third stray capacitance and the stray capacitance to ground may be determined by solving the following equation to achieve optimal estimation of the stray parameters of the third stray capacitance and the stray capacitance to ground.

[0086]

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

[0088] In one possible implementation, 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 according to the maximum value, including the following steps 601 to 603. Wherein:

[0089] S601, obtaining initial stray parameters of a third stray capacitance and a stray capacitance to ground.

[0090] Optionally, the initial stray parameters of the third stray capacitor are and the initial stray parameters of the stray capacitance to ground It can be the standard value given by the manufacturer before leaving the factory.

[0091] S602, determining a search range according to each initial spurious parameter, and determining a plurality of parameter combinations according to each search range.

[0092] The parameter combination includes candidate stray parameters of the third stray capacitance and candidate stray parameters of the stray capacitance.

[0093] Optionally, the search range corresponding to the third stray capacitance may be determined according to the initial stray parameters of the third stray capacitance. The first search range is determined by ±50%, that is, [0.5 , 1.5 ], and the search range can also be expanded or reduced according to actual conditions. The embodiment of the present application does not limit the size of the search range.

[0094] Similarly, the initial spurious parameters can be The second search range is determined by ±50% of [0.5 , 1.5 ] The search range can be expanded or reduced according to actual conditions. The embodiment of the present application does not limit the size of the search range.

[0095] Optionally, n numbers may be determined in the first search range. The candidate value of is determined in the second search range. Candidate value, based on n The candidate values ​​and n The candidate values ​​form an n×n grid, each grid can include a set of parameter combinations, and the size of n, that is, the number of grids (precision), can be flexibly set according to actual conditions.

[0096] S603, calculating an objective function according to each parameter combination, and when the objective function reaches a maximum value, determining stray parameters of a third stray capacitance and a stray capacitance to ground according to the parameter combination.

[0097] Optional, for each parameter combination Candidate values ​​and The candidate value determines the value of the objective function, that is, the value of solving the frequency response characteristic expression. When |H| takes the maximum value, the corresponding candidate value is used as the stray parameter of the third stray capacitance and the stray capacitance to ground.

[0098] It can be understood that when there are two or more maxima in the frequency response characteristic curve, the equivalent impedance of the branch where the damper is located in the calculation of H The equivalent impedance of the branch where the stray capacitance to ground is located hour, The value of can be any of the maximum values, for example, there are two maximum values When, based on The maximum value of the objective function is determined and based on The maximum value of the objective function determined may be different, but based on The maximum value of the objective function is determined and , and based on The maximum value of the objective function is determined and are the same, therefore, the determined results can also be mutually verified by the maximum value.

[0099] In another possible implementation, the stray parameters of the third stray capacitance and the stray capacitance to ground when the maximum value of the objective function is satisfied can be determined by an optimization algorithm such as a genetic algorithm, a particle swarm algorithm, or an ant colony algorithm. It can be understood that the capacitance value of the third stray capacitance and the capacitance value of the stray capacitance to ground corresponding to the maximum value of the objective function can be used as stray parameters.

[0100] In an exemplary embodiment, Figure 7As shown, optionally, the minimum value in the frequency response characteristic curve includes a first minimum value and a second minimum value, and determining the stray parameters of the first stray capacitance and the second stray capacitance according to the minimum value in the frequency response characteristic curve includes the following steps 701 to 702. Wherein:

[0101] S701, determining a stray parameter of a first stray capacitance according to a first minimum value, an inductance of a compensation reactor coil, and a resistance of the compensation reactor coil.

[0102] S702: Determine a stray parameter of a second stray capacitance according to the second minimum value, the winding inductance, and the winding resistance.

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

[0104]

[0105]

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

[0107] As an optional implementation, Figure 8 As shown, the method for determining the stray parameters provided in the embodiment of the present application may include the following specific steps:

[0108] S801, applying a unit pulse voltage excitation to a capacitor voltage transformer, and determining a frequency response characteristic curve of the capacitor voltage transformer.

[0109] S802: Obtain an equivalent circuit model of a capacitive voltage transformer.

[0110] Equivalent circuit model of capacitive voltage transformer, including voltage dividing capacitor, compensating reactor, transformer and damper;

[0111] The compensating reactor comprises an inductance of a compensating reactor coil, a resistance of the compensating reactor coil and a first stray capacitance, wherein the inductance of the compensating reactor coil and the 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 a first end of the first series branch is connected in series with a voltage-dividing capacitor;

[0112] A transformer, comprising a winding inductance, a winding resistance, a stray capacitance to ground, and a second stray capacitance, wherein 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, and a first end of the second series branch is connected to both 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: Determine a stray parameter of a first stray capacitor according to a first minimum value in the frequency response characteristic curve, an inductance of the compensation reactor coil, and a resistance of the compensation reactor coil.

[0115] S804: Determine a stray parameter of a second stray capacitance according to a second minimum value in the frequency response characteristic curve, a winding inductance, and a winding resistance.

[0116] S805, obtaining the target function.

[0117] The objective function may be a frequency response characteristic expression of an equivalent circuit model, and the frequency response characteristic expression is determined by a maximum value, a minimum value and various spurious parameters.

[0118] S806: Obtain initial stray parameters of the third stray capacitance and the stray capacitance to ground.

[0119] S807, determining a search range according to each initial spurious parameter, and determining a plurality of parameter combinations according to each search range.

[0120] The parameter combination includes candidate stray parameters of the third stray capacitance and candidate stray parameters of the stray capacitance.

[0121] S808, calculating the objective function according to each parameter combination, and when the objective function reaches a maximum value, determining the stray parameters of the third stray capacitance and the stray capacitance to ground according to the parameter combination.

[0122] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0123] For example, a CVT frequency response characteristic test 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 synchronously. The amplitude-frequency characteristic curve of the CVT is as follows: Fig. 9 As shown, the amplitude-frequency characteristic curve is at f max_1 =441Hz and f max_2 =2200Hz has a maximum value, and at f min_1 =510Hz and f min_2 =8657Hz has a minimum value.

[0124] According to f min_1 and f min_2 Calculate the capacitance value C of the first stray capacitance k and the capacitance value of the second stray capacitance C ps , then according to C p and C s The search range was determined by taking the standard value of (all 100 pF) and dividing it into 500 × 500 grids. k and C ps , using f max_1 and f max_2 Calculate the |H| corresponding to the grid respectively, such as Fig.10 As shown, at the grid coordinate (247, 269), |H| takes the maximum value of 184439×10 5 , the parameter combination in the grid is determined as the capacitance value of the stray capacitance to ground and the capacitance value of the third stray capacitance C s The corresponding stray parameters and relative errors are shown in Table 1. The stray parameter determination method proposed in the embodiment of the present application has an estimation error of no more than 4% for stray capacitance, and can accurately calculate the stray parameters of the CVT based on the frequency response characteristics of the CVT.

[0125] Table 1

[0126]

[0127] Based on the same inventive concept, the embodiment of the present application further provides a spurious parameter determination device for implementing the spurious parameter determination method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of one or more spurious parameter determination devices provided below can refer to the limitations of the spurious parameter determination method above, and will not be repeated here.

[0128] In an exemplary embodiment, Fig.11 As shown, a spurious 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 capacitor voltage transformer and determine a frequency response characteristic curve of the capacitor voltage transformer;

[0130] A second acquisition module 1102 is used to acquire an equivalent circuit model of a capacitive voltage transformer;

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

[0132] In an exemplary embodiment, the equivalent circuit model of the capacitive voltage transformer includes a voltage-dividing 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 the first stray capacitance, the inductance of the compensating reactor coil and the 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-dividing 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, and 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 capacitance, 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 capacitance, 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 capacitance to ground.

[0133] In an exemplary embodiment, the determination module 1103 is specifically used to determine the stray parameters of the first stray capacitance and the second stray capacitance according to the minimum value in the frequency response characteristic curve; determine the stray parameters of the third stray capacitance and the stray capacitance to ground according to the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitance and the second stray capacitance.

[0134] In an exemplary embodiment, the determination module 1103 is specifically used to obtain an objective function, which may be an expression of a frequency response characteristic of an equivalent circuit model, wherein the expression of the frequency response characteristic is determined by a maximum value, a minimum value, and various stray parameters; a maximum value of the objective function is determined according to a preset optimization algorithm, and stray parameters of a third stray capacitance and a stray capacitance to ground are determined according to the maximum value.

[0135] In an exemplary embodiment, the determination module 1103 is specifically used to obtain initial stray parameters of the third stray capacitance and the stray capacitance to ground; determine a search range according to each initial stray parameter, and determine multiple groups of parameter combinations according to each search range, the parameter combination including candidate stray parameters of the third stray capacitance and candidate stray parameters of the stray capacitance; calculate the objective function according to each parameter combination, and when the objective function reaches a maximum value, determine the stray parameters of the third stray capacitance and the stray capacitance to ground 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, and the determination module 1103 is specifically used to determine the stray parameters of the first stray capacitance according to the first minimum value, the inductance of the compensation reactor coil, and the resistance of the compensation reactor coil; and determine the stray parameters of the second stray capacitance according to the second minimum value, the winding inductance, and the winding resistance.

[0137] Each module in the above-mentioned spurious parameter determination device can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0138] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Fig.12As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for determining a stray parameter is implemented.

[0139] Those skilled in the art will understand that Fig.12 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0140] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps described in any of the above method embodiments when executing the computer program.

[0141] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps described in any of the above method embodiments are implemented.

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

[0143] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present 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. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0144] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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 above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for determining a stray parameter, characterized in that: The method comprises: Applying a unit pulse voltage excitation to a capacitor voltage transformer and determining a frequency response characteristic curve of the capacitor voltage transformer; Obtaining an equivalent circuit model of the capacitive voltage transformer; The stray parameters of the capacitive voltage transformer are determined according to the minimum value and the maximum value in the equivalent circuit model and the frequency response characteristic curve.

2. The method according to claim 1, characterized in that The equivalent circuit model of the capacitive voltage transformer includes a voltage dividing capacitor, a compensating reactor, a transformer and a damper; The compensating reactor comprises an inductance of a compensating reactor coil, a resistance of the compensating reactor coil and a first stray capacitance, the inductance of the compensating reactor coil and the 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 a first end of the first series branch is connected in series with the voltage-dividing capacitor; The transformer comprises a winding inductance, a winding resistance, a stray capacitance to ground, and a second stray capacitance, wherein 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, and a first end of the second series branch is connected to both 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.

3. The method according to claim 2, characterized in that Determining the stray parameters of the capacitive voltage transformer according to the equivalent circuit model and the minimum value and the maximum value in the frequency response characteristic curve includes: Determine the stray parameters of the first stray capacitance and the second stray capacitance according to the minimum value in the frequency response characteristic curve; The stray parameters of the third stray capacitance and the stray capacitance to ground are determined according to the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitance and the second stray capacitance.

4. The method according to claim 3, characterized in that The determining the stray parameters of the third stray capacitance and the stray capacitance to ground according to the maximum value in the frequency response characteristic curve and the stray parameters of the first stray capacitance and the second stray capacitance comprises: Obtaining an objective function, wherein the objective function may be an expression of a frequency response characteristic of the equivalent circuit model, wherein the expression of the frequency response characteristic 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 capacitance and the stray capacitance to ground are determined according to the maximum value.

5. The method according to claim 4, 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, comprises: Acquiring initial stray parameters of the third stray capacitance and the stray capacitance to ground; Determine a search range according to each of the initial stray parameters, and determine a plurality of parameter combinations according to each of the search ranges, wherein the parameter combinations include candidate stray parameters of the third stray capacitance and candidate stray parameters of the stray capacitance; The objective function is calculated according to each of the parameter combinations, and when the objective function reaches a maximum value, the stray parameters of the third stray capacitance and the stray capacitance to ground are determined according to the parameter combination.

6. The method according to claim 3, characterized in that The minimum value in the frequency response characteristic curve includes a first minimum value and a second minimum value, and determining the stray parameters of the first stray capacitance and the second stray capacitance according to the minimum value in the frequency response characteristic curve includes: determining a stray parameter of the first stray capacitance according to the first minimum value, the inductance of the compensating reactor coil, and the resistance of the compensating reactor coil; A stray parameter of the second stray capacitance is determined according to the second minimum value, the winding inductance, and the winding resistance.

7. A spurious parameter determination device, characterized in that: The device comprises: A first acquisition module, used for applying a unit pulse voltage excitation to a capacitive voltage transformer and determining a frequency response characteristic curve of the capacitive voltage transformer; A second acquisition module, used to acquire an equivalent circuit model of the capacitive voltage transformer; A determination module is used to determine the stray parameters of the capacitive voltage transformer according to the equivalent circuit model and the minimum value and the maximum value in the frequency response characteristic curve.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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