Method and device for calculating distributed capacitance of electromagnetic voltage transformer

Abstract

The invention discloses a method and a device for calculating distributed capacitance of an electromagnetic voltage transformer. The method comprises the following steps: constructing a capacitance parameter correlation constraint equation of the electromagnetic voltage transformer; opening a primary terminal of the electromagnetic voltage transformer, applying excitation of different frequencies to a secondary terminal of the electromagnetic voltage transformer, and obtaining iron core equivalent excitation impedance, open-circuit parallel resonant frequency and open-circuit series resonant frequency of the electromagnetic voltage transformer; performing short circuit on a primary terminal of the electromagnetic voltage transformer, applying excitation of different frequencies to a secondary terminal of the electromagnetic voltage transformer, and obtaining primary and secondary winding equivalent impedance and short circuit parallel resonant frequency of the electromagnetic voltage transformer; and substituting the iron core equivalent excitation impedance, the primary and secondary winding equivalent impedance, the open-circuit parallel resonant frequency, the open-circuit series resonant frequency and the short-circuit parallel resonant frequency into a capacitance parameter correlation constraint equation, and calculating the distributed capacitance of the electromagnetic capacitance transformer.

Description

Technical Field

[0001] The present invention relates to the technical field of alternating current voltage testing, and more specifically, to a method and device for calculating distributed capacitance of an electromagnetic voltage transformer. Background Art

[0002] Electromagnetic voltage transformers face great challenges in the development process. On the one hand, with the increase of operating frequency, the parasitic parameter effects of high and low voltage windings will affect the operating characteristics of the body, and therefore cannot be ignored; the core material characteristics and insulation material characteristics of electromagnetic voltage transformers at high frequencies are also significantly different from those at power frequencies. This results in the electromagnetic design theory and methods of traditional electromagnetic voltage transformers no longer being applicable. On the other hand, with the increase of capacity and voltage levels, some traditional core materials commonly used in electromagnetic voltage transformers (such as ferrites) are no longer applicable due to their low saturation magnetic flux density and low mechanical strength. Metallic soft magnetic materials (such as nanocrystalline alloys) with low loss density, high saturation magnetic flux density and high mechanical strength at high frequencies may replace traditional core materials for electromagnetic voltage transformers. However, the high-frequency magnetization characteristics, loss characteristics, and multi-physical field characteristics such as temperature rise, noise, and vibration of these metallic soft magnetic materials are still unclear, which brings great difficulties to the industrial development of electromagnetic voltage transformers. In addition, the number of turns of electromagnetic voltage transformers is becoming larger and larger, and the structure is becoming more and more complex, which makes the internal electromagnetic energy coupled with each other, and the parasitic parameters are interdependent and mutually restricted, which brings severe challenges to the establishment of the equivalent circuit / magnetic circuit model of the electromagnetic voltage transformer and the extraction of resistance, inductance and capacitance parameters, and ultimately leads to unclear understanding of the operating characteristics of the electromagnetic voltage transformer. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a method and device for calculating the distributed capacitance of an electromagnetic voltage transformer.

[0004] According to one aspect of the present invention, a method for calculating distributed capacitance of an electromagnetic voltage transformer is provided, comprising:

[0005] Construct the capacitance parameter-related constraint equations of electromagnetic voltage transformer;

[0006] The primary terminal of the electromagnetic voltage transformer is opened, and different frequency excitations are applied to the secondary terminal of the electromagnetic voltage transformer to obtain a first voltage, a first current and an open circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer;

[0007] Calculate the equivalent excitation impedance of the core of the electromagnetic voltage transformer according to the first voltage and the first current, and obtain the open-circuit parallel resonant frequency and the open-circuit series resonant frequency of the electromagnetic voltage transformer according to the open-circuit impedance characteristic curve;

[0008] Short-circuiting the primary terminal of the electromagnetic voltage transformer and applying different frequency excitations to the secondary terminal of the electromagnetic voltage transformer to obtain a second voltage, a second current and a short-circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer;

[0009] Calculating the primary and secondary winding equivalent impedances of the electromagnetic voltage transformer according to the second voltage and the second current, and obtaining the short-circuit parallel resonant frequency of the electromagnetic voltage transformer according to the short-circuit impedance characteristic curve;

[0010] The equivalent excitation impedance of the core, the equivalent impedance of the primary and secondary windings, the open-circuit parallel resonant frequency, the open-circuit series resonant frequency and the short-circuit parallel resonant frequency are substituted into the capacitance parameter-related constraint equation to calculate the distributed capacitance of the electromagnetic capacitance transformer.

[0011] Optionally, a capacitance parameter-related constraint equation of the electromagnetic voltage transformer is constructed, including:

[0012] Construct the leakage magnetic branch admittance and excitation branch admittance of electromagnetic voltage transformer;

[0013] According to the admittance of the leakage magnetic branch and the admittance of the excitation branch, the admittance parameter matrix of the entire two-terminal network of the electromagnetic voltage transformer is constructed;

[0014] According to the admittance parameter matrix, the capacitance parameter-related constraint equations of the electromagnetic voltage transformer are established through resonant frequency analysis.

[0015] Optionally, the leakage flux branch admittance y l The expression is:

[0016]

[0017] Excitation branch admittance y m The expression is:

[0018]

[0019] In the formula, R s is the equivalent impedance of the primary and secondary windings of the electromagnetic voltage transformer, L s is the equivalent inductance of the primary and secondary windings, R m is the equivalent excitation resistance of the electromagnetic voltage transformer, L m is the equivalent excitation inductance, w=2πf, f is the operating frequency.

[0020] Optionally, the expression of the admittance parameter matrix is:

[0021]

[0022] In the formula, C p is the distributed capacitance of the primary winding to ground, C sis the distributed capacitance of the secondary winding to ground, C ps is the distributed capacitance of primary and secondary windings, y l is the leakage flux branch admittance, y m is the excitation branch admittance, Y M is the equivalent admittance matrix of the excitation branch and winding branch of the electromagnetic voltage transformer, Y C is the capacitance parameter admittance matrix of the electromagnetic voltage transformer.

[0023] Optionally, the capacitance parameter related constraint equation is:

[0024]

[0025] Where f1 and f2 are the parallel resonant frequency and series resonant frequency of the open circuit impedance characteristic, respectively; f3 is the parallel resonant frequency of the short circuit impedance characteristic; C p is the distributed capacitance of the primary winding to ground, C s is the distributed capacitance of the secondary winding to ground, C ps is the distributed capacitance of primary and secondary windings, L m is the equivalent excitation impedance of the core, L s is the equivalent impedance of the primary and secondary windings, and n is the transformer ratio.

[0026] Optionally, the distributed capacitance of the electromagnetic capacitor transformer includes: a distributed capacitance of the primary winding to ground, a distributed capacitance of the secondary winding to ground, and a distributed capacitance of the primary and secondary windings.

[0027] According to another aspect of the present invention, there is provided a device for calculating distributed capacitance of an electromagnetic voltage transformer, comprising:

[0028] A construction module for constructing constraint equations related to capacitance parameters of an electromagnetic voltage transformer;

[0029] A first acquisition module is used to open the primary terminal of the electromagnetic voltage transformer and apply different frequency excitations to the secondary terminal of the electromagnetic voltage transformer to obtain a first voltage, a first current and an open circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer;

[0030] A first calculation module, used to calculate the iron core equivalent excitation impedance of the electromagnetic voltage transformer according to the first voltage and the first current, and obtain the open circuit parallel resonant frequency and the open circuit series resonant frequency of the electromagnetic voltage transformer according to the open circuit impedance characteristic curve;

[0031] A second acquisition module is used to short-circuit the primary terminal of the electromagnetic voltage transformer and apply different frequency excitations to the secondary terminal of the electromagnetic voltage transformer to obtain a second voltage, a second current and a short-circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer;

[0032] A second calculation module is used to calculate the primary and secondary winding equivalent impedances of the electromagnetic voltage transformer according to the second voltage and the second current, and to obtain the short-circuit parallel resonant frequency of the electromagnetic voltage transformer according to the short-circuit impedance characteristic curve;

[0033] The third calculation module is used to bring the iron core equivalent excitation impedance, the primary and secondary winding equivalent impedance, the open circuit parallel resonant frequency, the open circuit series resonant frequency and the short circuit parallel resonant frequency into the capacitance parameter related constraint equation to calculate the distributed capacitance of the electromagnetic capacitor mutual inductor.

[0034] Optionally, build modules including:

[0035] The first construction module is used to construct the leakage magnetic branch admittance and the excitation branch admittance of the electromagnetic voltage transformer;

[0036] The second construction module is used to construct an admittance parameter matrix of the entire two-terminal network of the electromagnetic voltage transformer according to the admittance of the leakage magnetic branch and the admittance of the excitation branch;

[0037] A module is established for establishing capacitance parameter-related constraint equations of an electromagnetic voltage transformer through resonant frequency analysis based on an admittance parameter matrix.

[0038] Optionally, the leakage flux branch admittance y l The expression is:

[0039]

[0040] Excitation branch admittance y m The expression is:

[0041]

[0042] In the formula, R s is the equivalent impedance of the primary and secondary windings of the electromagnetic voltage transformer, L s is the equivalent inductance of the primary and secondary windings, R m is the equivalent excitation resistance of the electromagnetic voltage transformer, L m is the equivalent excitation inductance, w=2πf, f is the operating frequency.

[0043] Optionally, the expression of the admittance parameter matrix is:

[0044]

[0045] In the formula, C p is the distributed capacitance of the primary winding to ground, C s is the distributed capacitance of the secondary winding to ground, C ps is the distributed capacitance of primary and secondary windings, y l is the leakage flux branch admittance, y mis the excitation branch admittance, Y M is the equivalent admittance matrix of the excitation branch and winding branch of the electromagnetic voltage transformer, Y C is the capacitance parameter admittance matrix of the electromagnetic voltage transformer.

[0046] Optionally, the capacitance parameter related constraint equation is:

[0047]

[0048] Where f1 and f2 are the parallel resonant frequency and series resonant frequency of the open circuit impedance characteristic, respectively; f3 is the parallel resonant frequency of the short circuit impedance characteristic; C p is the distributed capacitance of the primary winding to ground, C s is the distributed capacitance of the secondary winding to ground, C ps is the distributed capacitance of primary and secondary windings, L m is the equivalent excitation impedance of the core, L s is the equivalent impedance of the primary and secondary windings, and n is the transformer ratio.

[0049] Optionally, the distributed capacitance of the electromagnetic capacitor transformer includes: a distributed capacitance of the primary winding to ground, a distributed capacitance of the secondary winding to ground, and a distributed capacitance of the primary and secondary windings.

[0050] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and the computer program is used to execute the method described in any one of the above aspects of the present invention.

[0051] According to another aspect of the present invention, an electronic device is provided, comprising: a processor; a memory for storing instructions executable by the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in any one of the above aspects of the present invention.

[0052] This application has the following technical effects:

[0053] 1. The traditional electromagnetic voltage transformer distributed capacitance is usually estimated by simulation calculation, and the calculation result is quite different from the actual equivalent distributed capacitance result. The present invention proposes a method for calculating the distributed capacitance of an electromagnetic voltage transformer. By performing an open-short circuit test on the electromagnetic voltage transformer, the equivalent excitation inductance, leakage inductance and resonant frequency point of the iron core are obtained, and then the primary winding-to-ground distributed capacitance, the secondary winding-to-ground distributed capacitance and the distributed capacitance between the primary and secondary windings of the electromagnetic voltage transformer are calculated.

[0054] 2. The method for calculating the distributed capacitance of the electromagnetic voltage transformer provided by the present invention is based on the open-circuit and short-circuit transmission characteristics of the electromagnetic voltage transformer, and actually calculates the equivalent distributed capacitance of the transformer. The calculation method is simple, and the result is accurate and reliable, which is of great significance for analyzing the transmission characteristics of the electromagnetic voltage transformer under wide-band excitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0056] Figure 1 It is a flow chart of a method for calculating distributed capacitance of an electromagnetic voltage transformer provided by an exemplary embodiment of the present invention;

[0057] Figure 2 is an equivalent principle diagram of an electromagnetic voltage transformer provided by an exemplary embodiment of the present invention;

[0058] Figure 3 is an open circuit impedance characteristic test wiring diagram provided by an exemplary embodiment of the present invention;

[0059] Figure 4 It is a short-circuit impedance characteristic test wiring diagram provided by an exemplary embodiment of the present invention;

[0060] Figure 5 It is a structural schematic diagram of a distributed capacitance calculation device for an electromagnetic voltage transformer provided by an exemplary embodiment of the present invention;

[0061] Figure 6 This is a structure of an electronic device provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0062] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described here.

[0063] It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0064] Those skilled in the art can understand that the terms "first" and "second" in the embodiments of the present invention are only used to distinguish different steps, devices or modules, etc., and neither represent any specific technical meaning nor indicate the necessary logical order between them.

[0065] It should also be understood that, in the embodiments of the present invention, “plurality” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0066] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0067] In addition, the term "and / or" in the present invention is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects before and after are in an "or" relationship.

[0068] It should also be understood that the description of the various embodiments of the present invention focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced to each other, and for the sake of brevity, they will not be described one by one.

[0069] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0070] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0071] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0072] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0073] Embodiments of the present invention can be applied to electronic devices such as terminal devices, computer systems, servers, etc., which can operate with many other general or special computing system environments or configurations. Examples of well-known terminal devices, computing systems, environments and / or configurations suitable for use with electronic devices such as terminal devices, computer systems, servers, etc. include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network personal computers, small computer systems, large computer systems, and distributed cloud computing technology environments including any of the above systems, etc.

[0074] Electronic devices such as terminal devices, computer systems, servers, etc. can be described in the general context of computer system executable instructions (such as program modules) executed by computer systems. Generally, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in a distributed cloud computing environment, where tasks are performed by remote processing devices linked through a communication network. In a distributed cloud computing environment, program modules can be located on local or remote computing system storage media including storage devices.

[0075] Exemplary Methods

[0076] Figure 1 FIG. 1 is a flow chart of a method for calculating the distributed capacitance of an electromagnetic voltage transformer provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as Figure 1 As shown, the method 100 for calculating the distributed capacitance of an electromagnetic voltage transformer includes the following steps:

[0077] Step 101, constructing capacitance parameter-related constraint equations of an electromagnetic voltage transformer;

[0078] Step 102, opening the primary terminal of the electromagnetic voltage transformer, applying different frequency excitations to the secondary terminal of the electromagnetic voltage transformer, and obtaining a first voltage, a first current and an open circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer;

[0079] Step 103, calculating the iron core equivalent excitation impedance of the electromagnetic voltage transformer according to the first voltage and the first current, and obtaining the open circuit parallel resonant frequency and the open circuit series resonant frequency of the electromagnetic voltage transformer according to the open circuit impedance characteristic curve;

[0080] Step 104, short-circuiting the primary terminal of the electromagnetic voltage transformer, applying different frequency excitations to the secondary terminal of the electromagnetic voltage transformer, and obtaining a second voltage, a second current and a short-circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer;

[0081] Step 105, calculating the primary and secondary winding equivalent impedances of the electromagnetic voltage transformer according to the second voltage and the second current, and obtaining the short-circuit parallel resonant frequency of the electromagnetic voltage transformer according to the short-circuit impedance characteristic curve;

[0082] Step 106, the core equivalent excitation impedance, the primary and secondary winding equivalent impedance, the open circuit parallel resonant frequency, the open circuit series resonant frequency and the short circuit parallel resonant frequency are substituted into the capacitance parameter related constraint equation to calculate the distributed capacitance of the electromagnetic capacitor transformer.

[0083] Specifically, the equivalent schematic diagram of the electromagnetic voltage transformer is as follows: Figure 2 As shown, C p is the distributed capacitance of the primary winding to ground, C s is the distributed capacitance of the secondary winding to ground, C ps is the distributed capacitance of primary and secondary windings, L m is the equivalent excitation impedance of the core, L s is the equivalent impedance of the primary and secondary windings, and n is the transformer ratio.

[0084] In the magnetic property characterization model, the leakage flux branch admittance is expressed as:

[0085]

[0086] The excitation branch admittance is expressed as:

[0087]

[0088] Considering that the two-port equivalent broadband model is still obtained by connecting the magnetic property characterization model and the capacitance effect characterization model in parallel through terminals, the admittance parameter matrices of the magnetic property characterization model and the capacitance effect characterization model can be analyzed separately to obtain the admittance parameter matrix of the entire two-port network.

[0089]

[0090] Based on the admittance parameter matrix, the network function and resonance characteristics of the electromagnetic voltage transformer can be obtained, and the constraint equation related to the capacitance parameters of the electromagnetic voltage transformer can be established through resonant frequency analysis. The correlation between the capacitance parameters of the electromagnetic voltage transformer and the resonant frequency of the open-short circuit impedance characteristics is shown as follows:

[0091]

[0092] Among them, f1 and f2 are the parallel resonant frequency and series resonant frequency of the open circuit impedance characteristic (Z1oc), and f3 is the parallel resonant frequency of the short circuit impedance characteristic (Z1sc).

[0093] The impedance characteristics of the electromagnetic voltage transformer are tested by two lock-in amplifiers. The specific test method is as follows:

[0094] 1)Reference Figure 3 As shown, the primary terminal of the electromagnetic voltage transformer is opened, and different frequency excitations are applied to the secondary terminals of the electromagnetic voltage transformer to obtain the secondary terminal voltage and current of the electromagnetic voltage transformer.

[0095] Ignore the winding impedance and the equivalent excitation resistance of the core, where the equivalent excitation impedance of the core is calculated as:

[0096]

[0097] At the same time, based on the open circuit impedance characteristic curve f[(U f1 I f1 ),(U f2 I f2 )...(U fn I fn )] oc , calculate the parallel resonant frequency f1 and the series resonant frequency f2;

[0098] 2)Reference Figure 4 As shown, the primary terminal of the electromagnetic voltage transformer is short-circuited, and different frequency excitations are applied to the secondary terminals of the electromagnetic voltage transformer to obtain the voltage and current of the secondary terminals of the electromagnetic voltage transformer.

[0099] Ignoring the winding impedance and the equivalent excitation resistance of the core, the equivalent impedance of the primary and secondary windings is calculated as:

[0100]

[0101] At the same time, based on the short-circuit impedance characteristic curve f[(U f1 I f1 ),(U f2 I f2 )...(U fn I fn )] sc , and obtain the parallel resonant frequency f3 of the short-circuit impedance characteristic.

[0102] 3) Based on L s , L m and resonant frequencies f1, f2, f3, the primary winding-to-ground distributed capacitance C is calculated by formula (4): p , the secondary winding to ground distributed capacitance C s And the primary and secondary winding distributed capacitance C ps .

[0103] This application has the following technical effects:

[0104] 1. The traditional electromagnetic voltage transformer distributed capacitance is usually estimated by simulation calculation, and the calculation result is quite different from the actual equivalent distributed capacitance result. The present invention proposes a method for calculating the distributed capacitance of an electromagnetic voltage transformer. By performing an open-short circuit test on the electromagnetic voltage transformer, the equivalent excitation inductance, leakage inductance and resonant frequency point of the iron core are obtained, and then the primary winding-to-ground distributed capacitance, the secondary winding-to-ground distributed capacitance and the distributed capacitance between the primary and secondary windings of the electromagnetic voltage transformer are calculated.

[0105] 2. The method for calculating the distributed capacitance of the electromagnetic voltage transformer provided by the present invention is based on the open-circuit and short-circuit transmission characteristics of the electromagnetic voltage transformer, and actually calculates the equivalent distributed capacitance of the transformer. The calculation method is simple, and the result is accurate and reliable, which is of great significance for analyzing the transmission characteristics of the electromagnetic voltage transformer under wide-band excitation.

[0106] Exemplary Devices

[0107] Figure 5 FIG. 1 is a schematic diagram of a structure of a distributed capacitance calculation device for an electromagnetic voltage transformer provided by an exemplary embodiment of the present invention. Figure 5 As shown, the device 500 includes:

[0108] A construction module 510 is used to construct a capacitance parameter-related constraint equation of an electromagnetic voltage transformer;

[0109] A first acquisition module 520 is used to open the primary terminal of the electromagnetic voltage transformer and apply different frequency excitations to the secondary terminal of the electromagnetic voltage transformer to obtain a first voltage, a first current and an open circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer;

[0110] A first calculation module 530, configured to calculate an equivalent excitation impedance of an iron core of the electromagnetic voltage transformer according to the first voltage and the first current, and to obtain an open circuit parallel resonant frequency and an open circuit series resonant frequency of the electromagnetic voltage transformer according to an open circuit impedance characteristic curve;

[0111] The second acquisition module 540 is used to short-circuit the primary terminal of the electromagnetic voltage transformer and apply different frequency excitations to the secondary terminal of the electromagnetic voltage transformer to obtain a second voltage, a second current and a short-circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer;

[0112] A second calculation module 550 is used to calculate the primary and secondary winding equivalent impedances of the electromagnetic voltage transformer according to the second voltage and the second current, and to obtain the short-circuit parallel resonant frequency of the electromagnetic voltage transformer according to the short-circuit impedance characteristic curve;

[0113] The third calculation module 560 is used to bring the iron core equivalent excitation impedance, the primary and secondary winding equivalent impedance, the open circuit parallel resonant frequency, the open circuit series resonant frequency and the short circuit parallel resonant frequency into the capacitance parameter related constraint equation to calculate the distributed capacitance of the electromagnetic capacitor mutual inductor.

[0114] Optionally, the construction module 510 includes:

[0115] The first construction submodule is used to construct the leakage magnetic branch admittance and the excitation branch admittance of the electromagnetic voltage transformer;

[0116] The second construction submodule is used to construct an admittance parameter matrix of the entire two-terminal network of the electromagnetic voltage transformer according to the admittance of the leakage magnetic branch and the admittance of the excitation branch;

[0117] A submodule is established to establish capacitance parameter-related constraint equations of an electromagnetic voltage transformer according to an admittance parameter matrix through resonant frequency analysis.

[0118] Optionally, the leakage flux branch admittance y l The expression is:

[0119]

[0120] Excitation branch admittance y m The expression is:

[0121]

[0122] In the formula, R s is the equivalent impedance of the primary and secondary windings of the electromagnetic voltage transformer, L s is the equivalent inductance of the primary and secondary windings, R m is the equivalent excitation resistance of the electromagnetic voltage transformer, L m is the equivalent excitation inductance, w=2πf, f is the operating frequency.

[0123] Optionally, the expression of the admittance parameter matrix is:

[0124]

[0125] In the formula, C p is the distributed capacitance of the primary winding to ground, C s is the distributed capacitance of the secondary winding to ground, C ps is the distributed capacitance of primary and secondary windings, y l is the leakage flux branch admittance, y m is the excitation branch admittance, Y M is the equivalent admittance matrix of the excitation branch and winding branch of the electromagnetic voltage transformer, Y C is the capacitance parameter admittance matrix of the electromagnetic voltage transformer.

[0126] Optionally, the capacitance parameter related constraint equation is:

[0127]

[0128] Where f1 and f2 are the parallel resonant frequency and series resonant frequency of the open circuit impedance characteristic, respectively; f3 is the parallel resonant frequency of the short circuit impedance characteristic; C p is the distributed capacitance of the primary winding to ground, C s is the distributed capacitance of the secondary winding to ground, C ps is the distributed capacitance of primary and secondary windings, Lm is the equivalent excitation impedance of the core, L s is the equivalent impedance of the primary and secondary windings, and n is the transformer ratio.

[0129] Optionally, the distributed capacitance of the electromagnetic capacitor transformer includes: a distributed capacitance of the primary winding to ground, a distributed capacitance of the secondary winding to ground, and a distributed capacitance of the primary and secondary windings.

[0130] Exemplary Electronic Devices

[0131] Figure 6 This is a structure of an electronic device provided by an exemplary embodiment of the present invention. Figure 6 As shown, the electronic device 60 includes one or more processors 61 and a memory 62 .

[0132] The processor 61 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0133] The memory 62 may include one or more computer program products, and the computer program product may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 61 may run the program instructions to implement the methods of the software programs of the various embodiments of the present invention described above and / or other desired functions. In one example, the electronic device may also include: an input device 63 and an output device 64, which are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0134] In addition, the input device 63 may also include, for example, a keyboard, a mouse, etc.

[0135] The output device 64 can output various information to the outside, and can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto.

[0136] Of course, to simplify, Figure 6 Only some of the components related to the present invention in the electronic device are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, according to specific application conditions, the electronic device may also include any other appropriate components.

[0137] Exemplary computer program products and computer-readable storage media

[0138] In addition to the above-mentioned methods and devices, an embodiment of the present invention may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the method according to various embodiments of the present invention described in the above-mentioned "Exemplary Method" section of this specification.

[0139] The computer program product may be written in any combination of one or more programming languages ​​to write program code for performing the operations of the embodiments of the present invention, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0140] In addition, an embodiment of the present invention may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, enable the processor to execute the steps of the method according to various embodiments of the present invention described in the above “Exemplary Method” section of this specification.

[0141] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, system or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0142] The basic principle of the present invention is described above in conjunction with specific embodiments. However, it should be pointed out that the advantages, strengths, effects, etc. mentioned in the present invention are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. must be possessed by each embodiment of the present invention. In addition, the specific details disclosed above are only for the purpose of illustration and facilitation of understanding, rather than limitation, and the above details do not limit the present invention to being implemented by adopting the above specific details.

[0143] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system embodiment, since it basically corresponds to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0144] The block diagrams of the devices, systems, equipment, and systems involved in the present invention are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, systems, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The word "such as" used here refers to the phrase "such as but not limited to", and can be used interchangeably with it.

[0145] The method and system of the present invention may be implemented in many ways. For example, the method and system of the present invention may be implemented by software, hardware, firmware or any combination of software, hardware, firmware. The above order of steps for the method is only for illustration, and the steps of the method of the present invention are not limited to the order specifically described above, unless otherwise specifically stated. In addition, in some embodiments, the present invention may also be implemented as a program recorded in a recording medium, which includes machine-readable instructions for implementing the method according to the present invention. Thus, the present invention also covers a recording medium storing a program for executing the method according to the present invention.

[0146] It should also be noted that in the system, device and method of the present invention, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. The above description of the disclosed aspects is provided to enable any technician in the field to make or use the present invention. Various modifications to these aspects are very obvious to those skilled in the art, and the general principles defined here can be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown here, but in accordance with the widest range consistent with the principles and novel features disclosed here.

[0147] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for calculating the distributed capacitance of an electromagnetic voltage transformer, characterized in that: include: Construct the capacitance parameter-related constraint equations of electromagnetic voltage transformer; Opening the primary terminal of the electromagnetic voltage transformer and applying different frequency excitations to the secondary terminal of the electromagnetic voltage transformer to obtain a first voltage, a first current and an open circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer; Calculating the iron core equivalent excitation impedance of the electromagnetic voltage transformer according to the first voltage and the first current, and acquiring the open circuit parallel resonant frequency and the open circuit series resonant frequency of the electromagnetic voltage transformer according to the open circuit impedance characteristic curve; Short-circuiting the primary terminal of the electromagnetic voltage transformer, applying different frequency excitations to the secondary terminal of the electromagnetic voltage transformer, and obtaining a second voltage, a second current and a short-circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer; Calculating the primary and secondary winding equivalent impedances of the electromagnetic voltage transformer according to the second voltage and the second current, and acquiring the short-circuit parallel resonant frequency of the electromagnetic voltage transformer according to the short-circuit impedance characteristic curve; The iron core equivalent excitation impedance, the primary and secondary winding equivalent impedance, the open circuit parallel resonant frequency, the open circuit series resonant frequency and the short circuit parallel resonant frequency are substituted into the capacitance parameter related constraint equation to calculate the distributed capacitance of the electromagnetic capacitor mutual inductor.

2. The method according to claim 1, characterized in that: Construct the capacitance parameter-related constraint equations of the electromagnetic voltage transformer, including: Constructing the leakage magnetic branch admittance and the excitation branch admittance of the electromagnetic voltage transformer; Constructing an admittance parameter matrix of the entire two-terminal network of the electromagnetic voltage transformer according to the admittance of the leakage magnetic branch and the admittance of the excitation branch; According to the admittance parameter matrix, a capacitance parameter-related constraint equation of the electromagnetic voltage transformer is established through resonant frequency analysis.

3. The method according to claim 2, characterized in that The leakage magnetic branch admittance y l The expression is: The excitation branch admittance y m The expression is: In the formula, R s is the equivalent impedance of the primary and secondary windings of the electromagnetic voltage transformer, L s is the equivalent inductance of the primary and secondary windings, R m is the equivalent excitation resistance of the electromagnetic voltage transformer, L m is the equivalent excitation inductance, w=2πf, f is the operating frequency.

4. The method according to claim 2, characterized in that: The expression of the admittance parameter matrix is: In the formula, C p is the distributed capacitance of the primary winding to ground, C s is the distributed capacitance of the secondary winding to ground, C ps is the distributed capacitance of primary and secondary windings, y l is the leakage flux branch admittance, y m is the excitation branch admittance, Y M is the equivalent admittance matrix of the excitation branch and winding branch of the electromagnetic voltage transformer, Y C is the capacitance parameter admittance matrix of the electromagnetic voltage transformer.

5. The method according to claim 2, characterized in that: The capacitance parameter related constraint equation is: Where f1 and f2 are the parallel resonant frequency and series resonant frequency of the open circuit impedance characteristic, respectively; f3 is the parallel resonant frequency of the short circuit impedance characteristic; C p is the distributed capacitance of the primary winding to ground, C s is the distributed capacitance of the secondary winding to ground, C ps is the distributed capacitance of primary and secondary windings, L m is the equivalent excitation impedance of the core, L s is the equivalent impedance of the primary and secondary windings, and n is the transformer ratio.

6. The method according to claim 1, characterized in that The distributed capacitance of the electromagnetic capacitance transformer includes: a primary winding-to-ground distributed capacitance, a secondary winding-to-ground distributed capacitance, and primary and secondary winding distributed capacitances.

7. A device for calculating distributed capacitance of an electromagnetic voltage transformer, characterized in that: include: A construction module for constructing constraint equations related to capacitance parameters of an electromagnetic voltage transformer; A first acquisition module is used to open the primary terminal of the electromagnetic voltage transformer, and apply different frequency excitations to the secondary terminal of the electromagnetic voltage transformer to obtain a first voltage, a first current and an open circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer; a first calculation module, configured to calculate an equivalent excitation impedance of an iron core of the electromagnetic voltage transformer according to the first voltage and the first current, and to obtain an open-circuit parallel resonant frequency and an open-circuit series resonant frequency of the electromagnetic voltage transformer according to the open-circuit impedance characteristic curve; A second acquisition module is used to short-circuit the primary terminal of the electromagnetic voltage transformer, and apply different frequency excitations to the secondary terminal of the electromagnetic voltage transformer to obtain a second voltage, a second current and a short-circuit impedance characteristic curve at a high frequency of the secondary terminal of the electromagnetic voltage transformer; a second calculation module, configured to calculate the primary and secondary winding equivalent impedances of the electromagnetic voltage transformer according to the second voltage and the second current, and to obtain the short-circuit parallel resonant frequency of the electromagnetic voltage transformer according to the short-circuit impedance characteristic curve; The third calculation module is used to bring the iron core equivalent excitation impedance, the primary and secondary winding equivalent impedance, the open circuit parallel resonant frequency, the open circuit series resonant frequency and the short circuit parallel resonant frequency into the capacitance parameter related constraint equation to calculate the distributed capacitance of the electromagnetic capacitor mutual inductor.

8. The device according to claim 7, characterized in that Building blocks, including: A first construction submodule is used to construct the leakage magnetic branch admittance and the excitation branch admittance of the electromagnetic voltage transformer; A second construction submodule is used to construct an admittance parameter matrix of the entire two-terminal network of the electromagnetic voltage transformer according to the leakage magnetic branch admittance and the excitation branch admittance; A submodule is established, which is used to establish a capacitance parameter-related constraint equation of the electromagnetic voltage transformer through resonant frequency analysis according to the admittance parameter matrix.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1 to 6.

10. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing instructions executable by the processor; The processor is used to read the executable instructions from the memory and execute the instructions to implement the method described in any one of claims 1 to 6.

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