Method and system for calculating winding impedance of electromagnetic voltage transformer

Abstract

The invention discloses a method and a system for calculating winding impedance of an electromagnetic voltage transformer, and belongs to the technical field of alternating voltage testing. The method comprises the steps that load errors of the electromagnetic voltage transformer under different loads are acquired, and a load error difference value is calculated based on the load errors under the different loads; calculating rotation coefficients under different load errors based on the load values and the power factors corresponding to the load errors under different loads; and calculating the winding impedance of the electromagnetic voltage transformer based on the load error difference value and the rotation coefficient. The calculation method is simple, the error under the full load can be obtained through theoretical calculation without test wiring, and the workload of operation and maintenance personnel is greatly reduced.

Description

Technical Field

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

[0002] Electromagnetic voltage transformers use the principle of electromagnetic induction to convert high voltage into a lower measurable voltage. It is mainly composed of primary winding, secondary winding and iron core. Winding impedance includes resistance and leakage inductance in primary and secondary windings, which directly affects the measurement accuracy of the transformer. The error characteristics of the transformer are mainly divided into phase error and amplitude error. Changes in winding impedance will affect these errors, especially under high load and nonlinear load. Factors such as winding material, winding structure, temperature, frequency, etc. will affect the calculation and practical application of winding impedance. Usually, AC measurement method, DC measurement method, etc. are used to obtain the impedance value of the winding. Summary of the invention

[0003] In view of the above problems, the present invention proposes a method for calculating the winding impedance of an electromagnetic voltage transformer, comprising:

[0004] Obtaining load errors of the electromagnetic voltage transformer under different loads, and calculating load error differences based on the load errors under different loads;

[0005] Based on the load value and power factor corresponding to the load error under different loads, the rotation coefficient under different load errors is calculated;

[0006] Based on the load error difference and the rotation coefficient, the winding impedance of the electromagnetic voltage transformer is calculated.

[0007] Optionally, based on the load value and power factor corresponding to the load error under different loads, the rotation coefficient under different load errors is calculated, and the calculation formula is as follows:

[0008] k2M2-k1M1

[0009] Among them, k1, k2, M1 and M2 are coefficients.

[0010] Optionally, k1 and k2 are calculated as follows:

[0011]

[0012]

[0013] Among them, S1 and S2 are the secondary loads corresponding to the two error points. is the secondary voltage of the electromagnetic voltage transformer.

[0014] Optionally, the calculation formulas for M1 and M2 are as follows:

[0015]

[0016]

[0017] in, and They are the power factor angles corresponding to the two error points respectively.

[0018] Optionally, the winding impedance of the electromagnetic voltage transformer is calculated, including:

[0019]

[0020] in, and are the first test point error and the second test point error respectively. On the other hand, the present invention also proposes a calculation system for the winding impedance of an electromagnetic voltage transformer, comprising:

[0021] A first calculation unit is used to obtain the load error of the electromagnetic voltage transformer under different loads, and calculate the load error difference based on the load error under different loads;

[0022] A second calculation unit is used to calculate the rotation coefficient under different load errors based on the load values ​​and power factors corresponding to the load errors under different loads;

[0023] The third calculation unit is used to calculate the winding impedance of the electromagnetic voltage transformer based on the load error difference and the rotation coefficient.

[0024] Optionally, based on the load value and power factor corresponding to the load error under different loads, the rotation coefficient under different load errors is calculated, and the calculation formula is as follows:

[0025] k2M2-k1M1

[0026] Among them, k1, k2, M1 and M2 are coefficients.

[0027] Optionally, k1 and k2 are calculated as follows:

[0028]

[0029]

[0030] Among them, S1 and S2 are the secondary loads corresponding to the two error points. is the secondary voltage of the electromagnetic voltage transformer.

[0031] Optionally, the calculation formulas for M1 and M2 are as follows:

[0032]

[0033]

[0034] in, and They are the power factor angles corresponding to the two error points respectively.

[0035] Optionally, the winding impedance of the electromagnetic voltage transformer is calculated, including:

[0036]

[0037] in, and They are the first test point error and the second test point error respectively.

[0038] In yet another aspect, the present invention further provides a computing device, comprising: one or more processors;

[0039] a processor for executing one or more programs;

[0040] When the one or more programs are executed by the one or more processors, the above-described method is implemented.

[0041] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, the method described above is implemented.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention provides a method for calculating the winding impedance of an electromagnetic voltage transformer, comprising: obtaining the load error of the electromagnetic voltage transformer under different loads, and calculating the load error difference based on the load error under different loads; calculating the rotation coefficient under different load errors based on the load value and power factor corresponding to the load error under different loads; and calculating the winding impedance of the electromagnetic voltage transformer based on the load error difference and the rotation coefficient. The calculation method of the present invention is simple, and no test wiring is required for the error under full load, and it can be obtained through theoretical calculation, which will greatly reduce the workload of operation and maintenance personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a flow chart of the method of the present invention;

[0045] Figure 2 It is a structural diagram of the system of the present invention. DETAILED DESCRIPTION

[0046] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0047] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0048] Embodiment 1:

[0049] The present invention proposes a method for calculating the winding impedance of an electromagnetic voltage transformer, such as Figure 1 As shown, including:

[0050] Step 1, obtaining the load error of the electromagnetic voltage transformer under different loads, and calculating the load error difference based on the load error under different loads;

[0051] Step 2: Based on the load values ​​and power factors corresponding to the load errors under different loads, the rotation coefficients under different load errors are calculated;

[0052] Step 3: Based on the load error difference and the rotation coefficient, the winding impedance of the electromagnetic voltage transformer is calculated.

[0053] Among them, based on the load value and power factor corresponding to the load error under different loads, the rotation coefficient under different load errors is calculated, and the calculation formula is as follows:

[0054] k2M2-k1M1

[0055] Among them, k1, k2, M1 and M2 are coefficients.

[0056] The calculation formulas for k1 and k2 are as follows:

[0057]

[0058]

[0059] Among them, S1 and S2 are the secondary loads corresponding to the two error points. is the secondary voltage of the electromagnetic voltage transformer.

[0060] The calculation formulas for M1 and M2 are as follows:

[0061]

[0062]

[0063] in, and They are the power factor angles corresponding to the two error points respectively.

[0064] Among them, the winding impedance of the electromagnetic voltage transformer is calculated, including:

[0065]

[0066] in, and They are the first test point error and the second test point error respectively.

[0067] The calculation principle of the present invention is described below:

[0068] The present invention can calculate the primary and secondary winding impedances of the electromagnetic voltage transformer through the errors under any two loads;

[0069] The present invention requires three steps when calculating the winding impedance:

[0070] 1) Calculate the load error difference through the electromagnetic voltage transformer error under different loads

[0071] 2) Calculate the rotation coefficient k2M2-k1M1 under different errors by using the load value and power factor corresponding to the known error;

[0072] 3) Calculate the winding impedance of the electromagnetic voltage transformer, which is

[0073] Among them, the error vector of electromagnetic voltage transformer can be expressed as:

[0074]

[0075] Where S is the secondary load, U2 is the secondary voltage, R1 and R2 are the DC resistances of the primary and secondary windings, X1 and X2 are the leakage inductances of the primary and secondary windings, is the power factor angle.

[0076] Under the same test voltage, the no-load error remains basically constant.

[0077] Therefore, equation (1) indicates that the voltage transformer error vector can be obtained in the following way:

[0078] The coordinates of the two known error test points are X1(f1,δ1) and X2(f2,δ2), the corresponding secondary loads are S1 and S2, and the power factor angles are and

[0079] The calculation method is as follows:

[0080]

[0081] in:

[0082]

[0083] The present invention only needs to know the errors of the electromagnetic voltage transformer under any two loads to calculate the primary and secondary winding impedances of the electromagnetic voltage transformer.

[0084] Embodiment 2:

[0085] The present invention also proposes a calculation system 200 for the winding impedance of an electromagnetic voltage transformer, such as Figure 2 As shown, including:

[0086] The first calculation unit 201 is used to obtain the load error of the electromagnetic voltage transformer under different loads, and calculate the load error difference based on the load error under different loads;

[0087] The second calculation unit 202 is used to calculate the rotation coefficient under different load errors based on the load values ​​and power factors corresponding to the load errors under different loads;

[0088] The third calculation unit 203 is used to calculate the winding impedance of the electromagnetic voltage transformer based on the load error difference and the rotation coefficient.

[0089] Among them, based on the load value and power factor corresponding to the load error under different loads, the rotation coefficient under different load errors is calculated, and the calculation formula is as follows:

[0090] k2M2-k1M1

[0091] Among them, k1, k2, M1 and M2 are coefficients.

[0092] The calculation formulas for k1 and k2 are as follows:

[0093]

[0094]

[0095] Among them, S1 and S2 are the secondary loads corresponding to the two error points. is the secondary voltage of the electromagnetic voltage transformer.

[0096] The calculation formulas for M1 and M2 are as follows:

[0097]

[0098]

[0099] in, and They are the power factor angles corresponding to the two error points respectively.

[0100] Among them, the winding impedance of the electromagnetic voltage transformer is calculated, including:

[0101]

[0102] in, and They are the first test point error and the second test point error respectively.

[0103] The calculation method of the present invention is simple and can be obtained through theoretical calculation without the need for conducting test wiring for the error under full load, which will greatly reduce the workload of operation and maintenance personnel.

[0104] Embodiment 3:

[0105] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the method in the above embodiment.

[0106] Embodiment 4:

[0107] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both a built-in storage medium in a computer device and an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiment.

[0108] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0109] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0110] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0111] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0112] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0113] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for calculating the winding impedance of an electromagnetic voltage transformer, characterized in that: include: Obtaining load errors of the electromagnetic voltage transformer under different loads, and calculating load error differences based on the load errors under different loads; Based on the load value and power factor corresponding to the load error under different loads, the rotation coefficient under different load errors is calculated; Based on the load error difference and the rotation coefficient, the winding impedance of the electromagnetic voltage transformer is calculated.

2. The calculation method according to claim 1, characterized in that: Based on the load value and power factor corresponding to the load error under different loads, the rotation coefficient under different load errors is calculated, and the calculation formula is as follows: k2M2-k1M1 Among them, k1, k2, M1 and M2 are coefficients.

3. The calculation method according to claim 2, characterized in that: The calculation formulas of k1 and k2 are as follows: Among them, S1 and S2 are the secondary loads corresponding to the two error points. is the secondary voltage of the electromagnetic voltage transformer.

4. The calculation method according to claim 2, characterized in that: The calculation formulas of M1 and M2 are as follows: in, and They are the power factor angles corresponding to the two error points respectively.

5. The method according to claim 1, characterized in that: The calculation to obtain the winding impedance of the electromagnetic voltage transformer includes: in, and They are the first test point error and the second test point error respectively.

6. A calculation system for electromagnetic voltage transformer winding impedance, characterized in that: include: A first calculation unit is used to obtain the load error of the electromagnetic voltage transformer under different loads, and calculate the load error difference based on the load error under different loads; A second calculation unit is used to calculate the rotation coefficient under different load errors based on the load values ​​and power factors corresponding to the load errors under different loads; The third calculation unit is used to calculate the winding impedance of the electromagnetic voltage transformer based on the load error difference and the rotation coefficient.

7. The computing system according to claim 6, characterized in that: Based on the load value and power factor corresponding to the load error under different loads, the rotation coefficient under different load errors is calculated, and the calculation formula is as follows: k2M2-k1M1 Among them, k1, k2, M1 and M2 are coefficients.

8. The computing system according to claim 7, characterized in that: The calculation formulas of k1 and k2 are as follows: Among them, S1 and S2 are the secondary loads corresponding to the two error points. is the secondary voltage of the electromagnetic voltage transformer.

9. The computing system according to claim 7, characterized in that: The calculation formulas of M1 and M2 are as follows: in, and They are the power factor angles corresponding to the two error points respectively.

10. The system according to claim 6, characterized in that The calculation to obtain the winding impedance of the electromagnetic voltage transformer includes: in, and They are the first test point error and the second test point error respectively.

11. A computer device, characterized in that: include: one or more processors; a processor for executing one or more programs; When the one or more programs are executed by the one or more processors, the method according to any one of claims 1 to 5 is implemented.

12. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method according to any one of claims 1 to 5 is implemented.

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