Method and device for determining phase-to-phase coupling capacitance of lightning arrester, medium and equipment

Abstract

The application discloses a lightning arrester phase-to-phase coupling capacitor determination method and device, medium and equipment, relates to the electrical measurement field, and mainly aims to improve the low accuracy of the existing lightning arrester phase-to-phase coupling capacitor determination. Including: obtaining the fundamental wave voltage effective value, the third harmonic voltage effective value, the fundamental wave current effective value and the third harmonic current effective value of each phase target lightning arrester; based on the fundamental wave voltage effective value, the third harmonic voltage effective value, the fundamental wave current effective value and the third harmonic current effective value, constructing a first capacitive current relationship of each phase target lightning arrester under the interference of the fundamental wave phase-to-phase capacitor and a second capacitive current relationship of each phase target lightning arrester under the interference of the third harmonic phase-to-phase capacitor; based on the phase-to-phase coupling capacitor calculation model, the fundamental wave voltage effective value, the third harmonic voltage effective value, the fundamental wave current effective value and the third harmonic current effective value are calculated to obtain the phase-to-phase coupling capacitor between each phase target lightning arrester.

Description

Technical Field

[0001] This application relates to the field of electrical measurement technology, and in particular to a method, apparatus, medium, and equipment for determining the phase-to-phase coupling capacitance of a surge arrester. Background Technology

[0002] Metal oxide surge arresters (MOAs) possess excellent nonlinear volt-ampere characteristics and are widely used as protective components for power equipment in power systems. Therefore, the operational status of a surge arrester is crucial not only for its own safe operation but also for the safety of the protected equipment and the power grid. In practical operation, detecting the resistive current of the surge arrester plays a vital role in evaluating its insulation condition. Since surge arresters are typically arranged in a three-phase parallel configuration, the coupling capacitance current formed between the three phases is superimposed on the measured total leakage current of the arrester. This causes a change in the angle between the total leakage current and the reference voltage, resulting in variations in the resistive current detection due to interference from inter-phase capacitance. Consequently, the accuracy of the resistive current detection results decreases, thus reducing the accuracy of the surge arrester condition evaluation. Therefore, it is necessary to determine the inter-phase coupling capacitance of the surge arrester before detecting the resistive current.

[0003] Currently, the calculation method for interphase coupling capacitance used in testing simply relies on the mutual cancellation of the effects of the phase angle of phase B under the coupling capacitor currents of phases A and C. Phases A and C are compensated for interphase interference by half the difference in their phase angles. However, since the influence of phase B on the two adjacent phases is not consistent in the field, the accuracy of the above calculation method is low. Some literature also presents a method for eliminating interphase interference of surge arresters based on the zero-crossing point of the middle phase voltage, which is unaffected by grid harmonics. However, this method does not consider the interference current between phases A and C, and it is based on the assumption that the coupling capacitance between phases A and B is the same as that between phases B and C. Since the interference current in the resistive current test of surge arresters is affected by the line layout, interference currents exist between all three phases and vary in magnitude. Therefore, the accuracy of the above method remains low. In addition, there is a phase interference calculation and analysis method based on the finite element method. Although this method considers the interference current between the three phases, it requires obtaining the material properties of the surge arrester. The excessive introduction of parameters and the overly complex calculations reduce accuracy and limit its practical application. Therefore, there is an urgent need for a method to determine the phase-to-phase coupling capacitance of surge arresters in order to improve the above-mentioned problems. Summary of the Invention

[0004] In view of this, this application provides a method, apparatus, medium, and equipment for determining the interphase coupling capacitance of a surge arrester, with the main purpose of improving the problem of low accuracy in determining the interphase coupling capacitance of a surge arrester in existing methods.

[0005] According to one aspect of this application, a method for determining the phase-to-phase coupling capacitance of a surge arrester is provided, comprising:

[0006] The effective values ​​of the fundamental voltage, the third harmonic voltage, the fundamental current, and the third harmonic current of each phase target surge arrester are obtained respectively.

[0007] Based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, a first capacitive current relationship for each phase of the target surge arrester under fundamental phase-to-phase capacitance interference and a second capacitive current relationship for each phase of the target surge arrester under third harmonic phase-to-phase capacitance interference are constructed respectively.

[0008] The effective values ​​of the fundamental voltage, the third harmonic voltage, the fundamental current, and the third harmonic current are respectively processed by the interphase coupling capacitance calculation model to calculate the interphase coupling capacitance between the target surge arresters in each phase. The interphase coupling capacitance calculation model is constructed based on the first capacitive current relationship and the second capacitive current relationship.

[0009] Preferably, before constructing the first capacitive current relationship of each phase of the target surge arrester under fundamental phase-to-phase capacitance interference and the second capacitive current relationship of each phase of the target surge arrester under third harmonic phase-to-phase capacitance interference based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, the method further includes:

[0010] The phase difference data between the fundamental voltage data and the total leakage current of each phase target surge arrester, as well as the phase difference data between the third harmonic voltage data and the total leakage current, are obtained respectively.

[0011] The fundamental current effective value data is orthogonally decomposed based on the phase difference between the fundamental voltage data and the total leakage current of the target surge arrester in each phase to obtain the fundamental capacitive current effective value data of the target surge arrester in each phase.

[0012] The effective value data of the third harmonic current is orthogonally decomposed based on the phase difference between the third harmonic voltage data and the total leakage current of the target surge arrester in each phase, so as to obtain the effective value data of the third harmonic capacitive current of the target surge arrester in each phase.

[0013] Preferably, the step of constructing the first capacitive current relationship of each phase of the target surge arrester under fundamental phase-to-phase capacitance interference and the second capacitive current relationship of each phase of the target surge arrester under third harmonic phase-to-phase capacitance interference based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data specifically includes:

[0014] Based on vector relationships, a first capacitive current relationship is constructed between the effective value data of the fundamental capacitive current of the target surge arrester in each phase and the effective value data of the capacitive current of the surge arrester in each phase, and a second capacitive current relationship is constructed between the effective value data of the third harmonic capacitive current of the target surge arrester in each phase and the effective value data of the capacitive current of the surge arrester in each phase.

[0015] Preferably, the first capacitive current relationship is as follows: the effective value of the fundamental capacitive current of the target surge arrester in each phase is the difference between half of the effective value of the valve plate capacitor current of the current phase surge arrester and half of the sum of the effective values ​​of the coupling capacitor current of the other two phase surge arresters.

[0016] The second capacitive current relationship is as follows: the effective value of the third harmonic capacitive current of the target surge arrester in each phase is the sum of the effective value of the valve plate capacitor current of the current phase surge arrester and the effective value of the coupling capacitor current of the other two phase surge arresters.

[0017] Preferably, the step of acquiring the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data of each phase target surge arrester specifically includes:

[0018] The operating voltage and total leakage current of each phase target surge arrester were obtained separately;

[0019] The operating voltage and the total leakage current are respectively processed by signal conversion and Fourier transform to obtain the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data of the target surge arrester in each phase.

[0020] According to another aspect of this application, a device for determining the phase-to-phase coupling capacitance of a surge arrester is provided, comprising:

[0021] The acquisition module is used to acquire the fundamental voltage RMS value data, the third harmonic voltage RMS value data, the fundamental current RMS value data, and the third harmonic current RMS value data of each phase target surge arrester respectively;

[0022] The construction module is used to construct, respectively, the first capacitive current relationship of the target surge arrester in each phase under the fundamental phase-to-phase capacitance interference and the second capacitive current relationship of the target surge arrester in each phase under the third harmonic phase-to-phase capacitance interference based on the fundamental voltage effective value data, the third harmonic voltage effective value data, the fundamental current effective value data, and the third harmonic current effective value data.

[0023] The calculation module is used to perform interphase coupling capacitance calculation on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data based on the interphase coupling capacitance calculation model, respectively, to obtain the interphase coupling capacitance data between the target surge arresters in each phase. The interphase coupling capacitance calculation model is constructed based on the first capacitive current relationship and the second capacitive current relationship.

[0024] Preferably, prior to the building module, the device further includes:

[0025] The acquisition module is also used to acquire the phase difference data between the fundamental voltage data and the total leakage current of each phase target surge arrester, as well as the phase difference data between the third harmonic voltage data and the total leakage current.

[0026] The orthogonal decomposition module is used to perform orthogonal decomposition processing on the fundamental current effective value data based on the phase difference between the fundamental voltage data and the total leakage current of the target surge arrester in each phase, so as to obtain the fundamental capacitive current effective value data of the target surge arrester in each phase.

[0027] The orthogonal decomposition module is also used to perform orthogonal decomposition processing on the effective value data of the third harmonic current based on the phase difference between the third harmonic voltage data and the total leakage current of the target surge arrester in each phase, so as to obtain the effective value data of the third harmonic capacitive current of the target surge arrester in each phase.

[0028] Preferably, the building module is specifically used for:

[0029] Based on vector relationships, a first capacitive current relationship is constructed between the effective value data of the fundamental capacitive current of the target surge arrester in each phase and the effective value data of the capacitive current of the surge arrester in each phase, and a second capacitive current relationship is constructed between the effective value data of the third harmonic capacitive current of the target surge arrester in each phase and the effective value data of the capacitive current of the surge arrester in each phase.

[0030] Preferably, the first capacitive current relationship is as follows: the effective value of the fundamental capacitive current of the target surge arrester in each phase is the difference between half of the effective value of the valve plate capacitor current of the current phase surge arrester and half of the sum of the effective values ​​of the coupling capacitor current of the other two phase surge arresters.

[0031] The second capacitive current relationship is as follows: the effective value of the third harmonic capacitive current of the target surge arrester in each phase is the sum of the effective value of the valve plate capacitor current of the current phase surge arrester and the effective value of the coupling capacitor current of the other two phase surge arresters.

[0032] Preferably, the acquisition module specifically includes:

[0033] The acquisition unit is used to acquire the operating voltage and total leakage current of each phase target surge arrester;

[0034] The conversion unit is used to perform signal conversion processing and Fourier transform processing on the operating voltage and the total leakage current respectively to obtain the fundamental voltage effective value data, the third harmonic voltage effective value data, the fundamental current effective value data, and the third harmonic current effective value data of the target surge arrester in each phase.

[0035] According to another aspect of this application, a storage medium is provided that stores at least one executable instruction, which causes a processor to perform an operation corresponding to the method for determining the phase-to-phase coupling capacitance of a surge arrester described above.

[0036] According to another aspect of this application, a terminal is provided, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other through the communication bus;

[0037] The memory is used to store at least one executable instruction, which causes the processor to perform the operation corresponding to the method for determining the phase-to-phase coupling capacitance of the surge arrester.

[0038] By employing the above technical solutions, the technical solutions provided in the embodiments of this application have at least the following advantages:

[0039] This application provides a method, apparatus, medium, and equipment for determining the interphase coupling capacitance of surge arresters. First, the effective values ​​of the fundamental voltage, third harmonic voltage, fundamental current, and third harmonic current of each phase target surge arrester are acquired. Second, based on the fundamental voltage, third harmonic voltage, fundamental current, and third harmonic current data, a first capacitive current relationship and a second capacitive current relationship for each phase target surge arrester under fundamental phase-to-phase capacitance interference are constructed. Finally, based on the interphase coupling capacitance calculation model, the interphase coupling capacitance data of the fundamental voltage, third harmonic voltage, fundamental current, and third harmonic current are calculated to obtain the interphase coupling capacitance data between each phase target surge arrester. The interphase coupling capacitance calculation model is constructed based on the first and second capacitive current relationships. Compared with the prior art, the embodiments of this application construct a first capacitive current relationship for each phase target surge arrester under fundamental phase-to-phase capacitance interference and a second capacitive current relationship under third harmonic phase-to-phase capacitance interference. Based on the two capacitive current relationships, an interphase coupling capacitance calculation model is constructed for calculating the interphase coupling capacitance. Thus, based on the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data of each phase target surge arrester, the interphase coupling capacitance data between each phase target surge arrester is calculated through the interphase coupling capacitance calculation model, ensuring accuracy. At the same time, it is not necessary to introduce other parameters, and the calculation is simple.

[0040] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0041] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0042] Figure 1 A flowchart illustrating a method for determining the interphase coupling capacitance of a surge arrester according to an embodiment of this application is shown.

[0043] Figure 2 The diagram shows the calculation parameters of the interphase coupling capacitance provided in the embodiments of this application;

[0044] Figure 3 This shows a vector diagram of the fundamental component of a three-phase surge arrester provided in an embodiment of this application;

[0045] Figure 4 This shows a vector diagram of the third harmonic component of a three-phase surge arrester provided in an embodiment of this application;

[0046] Figure 5 This paper shows a vector relationship diagram of the effective value data of the fundamental capacitive current of the A-phase surge arrester provided in the embodiments of this application under the interference of the B and C phases;

[0047] Figure 6 This paper shows a vector relationship diagram of the effective value data of the third harmonic capacitive current of the A-phase surge arrester provided in the embodiment of this application under the interference of phases B and C;

[0048] Figure 7 A flowchart illustrating the calculation of interphase coupling capacitance data provided in an embodiment of this application is shown.

[0049] Figure 8 This paper shows a block diagram of a device for determining the phase-to-phase coupling capacitance of a surge arrester according to an embodiment of this application.

[0050] Figure 9 A schematic diagram of the structure of a terminal provided in an embodiment of this application is shown. Detailed Implementation

[0051] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0052] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0053] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0054] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0055] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0056] The embodiments of this application can be applied to computer systems / servers that can operate with a wide range of other general-purpose or special-purpose computing system environments or configurations. Examples of well-known computing systems, environments, and / or configurations suitable for use with computer systems / servers 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 PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems, etc.

[0057] Computer systems / servers can be described in the general context of computer system executable instructions (such as program modules) executed by the computer system. Typically, 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 distributed cloud computing environments, where tasks are performed by remote processing devices linked through a communication network. In distributed cloud computing environments, program modules can reside on local or remote computing system storage media, including storage devices.

[0058] This application provides a method for determining the interphase coupling capacitance of a surge arrester, such as... Figure 1 As shown, the method includes:

[0059] 101. Obtain the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data for each phase target surge arrester.

[0060] It is understandable that in complex periodic oscillations, due to the application of sinusoidal voltage to a nonlinear load, the fundamental current is distorted, generating harmonics. The fundamental current refers to the sinusoidal component with the longest period of the oscillation; harmonics refer to the electrical quantities in the current whose frequency is an integer multiple of the fundamental current. Typically, surge arresters in the field are arranged in a three-phase parallel configuration. In this embodiment, the target surge arrester is used to characterize the surge arrester under test, for example, phase A surge arrester, phase B surge arrester, and phase C surge arrester. Specifically, the effective value data U of the fundamental voltage of the three-phase target surge arresters A, B, and C are obtained respectively. a1 U b1 U c1 Third harmonic voltage RMS value data U a3 U b3 U c3 and fundamental current RMS data I a1 I b1 I c1 Third harmonic current RMS data I a3I b3 I c3 .

[0061] 102. Based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, construct the first capacitive current relationship of each phase target surge arrester under the fundamental phase-to-phase capacitance interference and the second capacitive current relationship of each phase target surge arrester under the third harmonic phase-to-phase capacitance interference, respectively.

[0062] In this embodiment, the first capacitive current relationship is used to characterize the relationship between the effective value of the fundamental capacitive current of the current target surge arrester and the effective value of the capacitive current generated by the other phase surge arresters; the second capacitive current relationship is used to characterize the relationship between the effective value of the third harmonic capacitive current of the current target surge arrester and the effective value of the capacitive current generated by the other phase surge arresters. Specifically, the effective value of the fundamental capacitive current and the effective value of the third harmonic capacitive current of each phase target surge arrester can be determined first based on the component vector relationship; then, the first capacitive current relationship and the second capacitive current relationship can be determined based on the vector relationship of the fundamental and third harmonic capacitive components of the current target surge arrester under the interference of the other two phase surge arresters.

[0063] 103. Based on the interphase coupling capacitance calculation model, the effective value data of the fundamental voltage, the effective value data of the third harmonic voltage, the effective value data of the fundamental current, and the effective value data of the third harmonic current are respectively processed to calculate the interphase coupling capacitance data between the target surge arresters of each phase.

[0064] The interphase coupling capacitance calculation model is constructed based on the first capacitive current relationship and the second capacitive current relationship. The interphase coupling capacitance calculation parameters are as follows: Figure 2 As shown, the effective values ​​of the three-phase fundamental voltage, the effective values ​​of the three-phase third harmonic voltage, the effective values ​​of the three-phase fundamental current, and the effective values ​​of the three-phase third harmonic current are respectively input into the phase-to-phase coupling capacitance calculation model for phase-to-phase coupling capacitance calculation, and the phase-to-phase coupling capacitance data between the target surge arresters of each phase can be obtained.

[0065] Compared with the prior art, the embodiments of this application construct a first capacitive current relationship for each phase target surge arrester under fundamental phase-to-phase capacitance interference and a second capacitive current relationship under third harmonic phase-to-phase capacitance interference. Based on the two capacitive current relationships, an interphase coupling capacitance calculation model is constructed for calculating the interphase coupling capacitance. Thus, based on the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data of each phase target surge arrester, the interphase coupling capacitance data between each phase target surge arrester is calculated through the interphase coupling capacitance calculation model, ensuring accuracy. At the same time, it is not necessary to introduce other parameters, and the calculation is simple.

[0066] For further explanation and limitation, in the embodiments of this application, before constructing the first capacitive current relationship of each phase target surge arrester under fundamental phase-to-phase capacitance interference and the second capacitive current relationship of each phase target surge arrester under third harmonic phase-to-phase capacitance interference based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, the method of the embodiments further includes: obtaining the phase difference data between the fundamental voltage data and the total leakage current of each phase target surge arrester and the phase difference data between the third harmonic voltage data and the total leakage current; performing orthogonal decomposition processing on the fundamental current RMS data based on the phase difference between the fundamental voltage data and the total leakage current of each phase target surge arrester to obtain the fundamental capacitive current RMS data of each phase target surge arrester; and performing orthogonal decomposition processing on the third harmonic current RMS data based on the phase difference between the third harmonic voltage data and the total leakage current of each phase target surge arrester to obtain the third harmonic capacitive current RMS data of each phase target surge arrester.

[0067] Specifically, the vector relationship of the fundamental component of a three-phase surge arrester, such as... Figure 3 As shown, where I a1 I b1 I c1 These represent the fundamental current RMS values ​​of the three-phase surge arrester, U and U, respectively. a1 U b1 U c1 These represent the fundamental voltage RMS values ​​of the three-phase surge arrester, Φ a1 Φ b1 Φ c1 The phase differences between the fundamental voltage and the total current of the three-phase surge arrester are represented by the two values ​​(which can be obtained through testing instruments). After orthogonal decomposition, the effective value data of the fundamental capacitive current of the three-phase target surge arrester are obtained. a1-c I b1-c I c1-c .

[0068] Based on the same principle, the vector relationship of the third harmonic components of a three-phase surge arrester is as follows: Figure 4 As shown, where I a3 I b3 I c3 U represents the effective value data of the third harmonic current of the three-phase surge arrester. a3 U b3 U c3 These represent the effective values ​​of the third harmonic voltage of the three-phase surge arrester, Φ a3 Φ b3 Φ c3 The phase differences between the third harmonic voltage and the total current of the three-phase surge arrester are represented by the numbers I and I, respectively. After orthogonal decomposition, the effective values ​​of the third harmonic capacitive current of the three-phase target surge arrester are obtained. a3-c I b3-c I c3-c .

[0069] Furthermore, in this embodiment, based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, a first capacitive current relationship formula for each phase target surge arrester under fundamental phase-to-phase capacitance interference and a second capacitive current relationship formula for each phase target surge arrester under third harmonic phase-to-phase capacitance interference are constructed. Specifically, this includes: based on vector relationships, constructing a first capacitive current relationship formula between the fundamental capacitive current RMS data of each phase target surge arrester and the capacitance current RMS data of each phase surge arrester, and a second capacitive current relationship formula between the third harmonic capacitive current RMS data of each phase target surge arrester and the capacitance current RMS data of each phase surge arrester.

[0070] For example, taking the A-phase surge arrester as an example, the vector relationship of the fundamental capacitive current RMS value of the A-phase surge arrester under interference from phases B and C is as follows: Figure 5 As shown, the fundamental capacitive current RMS value data I of the target surge arrester in phase A. a1-c The effective value of the current I is formed by the capacitance of the valence plate of the target surge arrester in phase A. aa1 Phase B voltage is coupled through interphase coupling capacitor C. ab The effective value of the formed capacitor current I ab1 And the C-phase voltage through the interphase coupling capacitor C ac The effective value of the formed capacitor current I ac1 Composed of together. According to Figure 5 The vector relationship shown can be used to further determine the effective value I of the fundamental capacitive current of phase A surge arrester. a1-c The effective value I of the current generated by the varistor capacitance of phase A surge arrester. aa1 Subtract the voltage of phase B through the interphase coupling capacitor C ab The effective value of the formed capacitor current I ab1 The voltage of phase C is coupled through the interphase coupling capacitor C. acThe effective value of the formed capacitor current I ac1 Half the sum of the two. Similarly, the effective value of the fundamental capacitive current I of the B-phase surge arrester. b1-c The effective value I of the current formed by the varistor capacitance of phase B surge arrester. bb1 Subtract the voltage of phase A through the interphase coupling capacitor C ab The effective value of the formed capacitor current I ab1 The voltage of phase C is coupled through the interphase coupling capacitor C. bc The effective value of the formed capacitor current I bc1 Half the sum of the two. And the effective value of the fundamental capacitive current I of the C-phase surge arrester. c1-c The effective value I of the current formed by the capacitor of the C-phase surge arrester valve plate. cc1 Subtract the voltage of phase A through the interphase coupling capacitor C ac The effective value of the formed capacitor current I ac1 The voltage of phase B is coupled through the interphase coupling capacitor C. bc The effective value of the formed capacitor current I bc1 Half of the sum of the two. Specifically, the first capacitive current relationship is as follows: the effective value of the fundamental capacitive current of each phase target surge arrester is the difference between half of the effective value of the valve plate capacitor current of the current phase surge arrester and half of the effective value of the coupling capacitor current of the other two phase surge arresters.

[0071] Furthermore, continuing the example above, the vector relationship between the effective value of the third harmonic capacitive current of phase A surge arrester under interference from phases B and C is as follows: Figure 6 As shown, since the third harmonic voltage phase angle is the same, the effective value data I of the third harmonic capacitive current of the target surge arrester in phase A is... a3-c The effective value I of the current formed by the varistor capacitance of phase A target surge arrester. aa3 Phase B voltage is coupled through interphase coupling capacitor C. ab The effective value of the formed capacitor current I ab3 And the C-phase voltage through the interphase coupling capacitor C ac The effective value of the formed capacitor current I ac3 The sum of the three. Similarly, the effective value data I of the third harmonic capacitive current of the B-phase target surge arrester. b3-c The effective value I of the current formed by the varistor capacitance of the B-phase target surge arrester. bb3 Phase A voltage is coupled through interphase coupling capacitor C. ab The effective value of the formed capacitor current I ab3 And the C-phase voltage through the interphase coupling capacitor C bc The effective value of the formed capacitor current I bc3 The sum of the three. And the effective value data of the third harmonic capacitive current of the C-phase target surge arrester I. c3-c The effective value I of the current formed by the varistor capacitance of the C-phase target surge arrester. cc3Phase A voltage is coupled through interphase coupling capacitor C. ac The effective value of the formed capacitor current I ac3 And the voltage of phase B through the interphase coupling capacitor C bc The effective value of the formed capacitor current I bc3 The sum of the three. Specifically, the second capacitive current relationship is as follows: the effective value of the third harmonic capacitive current of each phase target surge arrester is the sum of the effective value of the valve plate capacitor current of the current phase surge arrester and the effective value of the coupling capacitor current of the other two phase surge arresters.

[0072] For further explanation and limitation, in the embodiments of this application, the effective values ​​of the fundamental voltage, the third harmonic voltage, the fundamental current, and the third harmonic current of each phase target surge arrester are obtained respectively. Specifically, this includes: obtaining the operating voltage and total leakage current of each phase target surge arrester respectively; and performing signal conversion processing and Fourier transform processing on the operating voltage and total leakage current respectively to obtain the effective values ​​of the fundamental voltage, the third harmonic voltage, the fundamental current, and the third harmonic current of each phase target surge arrester.

[0073] Specifically, the operating voltage U of the three-phase target surge arrester can be obtained through a current sensor, preferably a high-precision current sensor. a U b U c and total leakage current I a I b I c The fundamental voltage RMS data U of the three-phase target surge arrester were extracted through signal conversion processing (i.e., A / D conversion) and Fourier transform processing (i.e., FFT analysis). a1 U b1 U c1 Third harmonic voltage RMS value data U a3 U b3 U c3 and fundamental current RMS data I a1 I b1 I c1 Third harmonic current RMS data I a3 I b3 I c3 .

[0074] In specific application scenarios, the calculation process for the phase-to-phase coupling capacitance data between target surge arresters is as follows: Figure 7As shown, firstly, the current and voltage data of the target surge arrester are acquired. The current data is then converted to digital (A / D) and analyzed using FFT to obtain the fundamental current RMS value, voltage-current phase angle difference, and the third harmonic current RMS value and voltage-current phase angle difference. Similarly, the voltage data is converted to digital (A / D) and analyzed using FFT to obtain the fundamental voltage RMS value, voltage-current phase angle difference, and the third harmonic voltage RMS value and voltage-current phase angle difference. Furthermore, based on the fundamental current RMS value, voltage-current phase angle difference, and the third harmonic current RMS value, the fundamental capacitive current RMS value is determined. Likewise, based on the third harmonic current RMS value, voltage-current phase angle difference, and the third harmonic voltage RMS value and voltage-current phase angle difference, the third harmonic capacitive current RMS value is determined.

[0075] This application provides a method for determining the interphase coupling capacitance of a surge arrester. First, the effective values ​​of the fundamental voltage, third harmonic voltage, fundamental current, and third harmonic current of each phase target surge arrester are obtained. Second, based on the fundamental voltage, third harmonic voltage, fundamental current, and third harmonic current data, a first capacitive current relationship and a second capacitive current relationship for each phase target surge arrester under fundamental phase-to-phase capacitance interference are constructed. Finally, based on the interphase coupling capacitance calculation model, the interphase coupling capacitance data of the fundamental voltage, third harmonic voltage, fundamental current, and third harmonic current are calculated to obtain the interphase coupling capacitance data between each phase target surge arrester. The interphase coupling capacitance calculation model is constructed based on the first and second capacitive current relationships. Compared with the prior art, the embodiments of this application construct a first capacitive current relationship for each phase target surge arrester under fundamental phase-to-phase capacitance interference and a second capacitive current relationship under third harmonic phase-to-phase capacitance interference. Based on the two capacitive current relationships, an interphase coupling capacitance calculation model is constructed for calculating the interphase coupling capacitance. Thus, based on the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data of each phase target surge arrester, the interphase coupling capacitance data between each phase target surge arrester is calculated through the interphase coupling capacitance calculation model, ensuring accuracy. At the same time, it is not necessary to introduce other parameters, and the calculation is simple.

[0076] Furthermore, as a response to the above Figure 1 The implementation of the method shown in this application provides a device for determining the interphase coupling capacitance of a surge arrester, such as... Figure 8 As shown, the device includes:

[0077] Get module 21, build module 22, calculate module 23.

[0078] The acquisition module 21 is used to acquire the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data of each phase target surge arrester respectively;

[0079] The construction module 22 is used to construct, based on the fundamental voltage effective value data, the third harmonic voltage effective value data, the fundamental current effective value data, and the third harmonic current effective value data, the target surge arrester of each phase under fundamental phase-to-phase capacitance interference and the target surge arrester of each phase under third harmonic phase-to-phase capacitance interference, respectively.

[0080] The calculation module 23 is used to perform interphase coupling capacitance calculation on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data based on the interphase coupling capacitance calculation model, respectively, to obtain the interphase coupling capacitance data between the target surge arresters in each phase. The interphase coupling capacitance calculation model is constructed based on the first capacitive current relationship and the second capacitive current relationship.

[0081] In specific application scenarios, before the building module, the device further includes:

[0082] The acquisition module is also used to acquire the phase difference data between the fundamental voltage data and the total leakage current of each phase target surge arrester, as well as the phase difference data between the third harmonic voltage data and the total leakage current.

[0083] The orthogonal decomposition module is used to perform orthogonal decomposition processing on the fundamental current effective value data based on the phase difference between the fundamental voltage data and the total leakage current of the target surge arrester in each phase, so as to obtain the fundamental capacitive current effective value data of the target surge arrester in each phase.

[0084] The orthogonal decomposition module is also used to perform orthogonal decomposition processing on the effective value data of the third harmonic current based on the phase difference between the third harmonic voltage data and the total leakage current of the target surge arrester in each phase, so as to obtain the effective value data of the third harmonic capacitive current of the target surge arrester in each phase.

[0085] In specific application scenarios, the building module is specifically used for:

[0086] Based on vector relationships, a first capacitive current relationship is constructed between the effective value data of the fundamental capacitive current of the target surge arrester in each phase and the effective value data of the capacitive current of the surge arrester in each phase, and a second capacitive current relationship is constructed between the effective value data of the third harmonic capacitive current of the target surge arrester in each phase and the effective value data of the capacitive current of the surge arrester in each phase.

[0087] In specific application scenarios, the first capacitive current relationship is as follows: the effective value of the fundamental capacitive current of each phase target surge arrester is the difference between half of the effective value of the valve plate capacitor current of the current phase surge arrester and half of the sum of the effective values ​​of the coupling capacitor current of the other two phase surge arresters.

[0088] The second capacitive current relationship is as follows: the effective value of the third harmonic capacitive current of the target surge arrester in each phase is the sum of the effective value of the valve plate capacitor current of the current phase surge arrester and the effective value of the coupling capacitor current of the other two phase surge arresters.

[0089] In specific application scenarios, the acquisition module specifically includes:

[0090] The acquisition unit is used to acquire the operating voltage and total leakage current of each phase target surge arrester;

[0091] The conversion unit is used to perform signal conversion processing and Fourier transform processing on the operating voltage and the total leakage current respectively to obtain the fundamental voltage effective value data, the third harmonic voltage effective value data, the fundamental current effective value data, and the third harmonic current effective value data of the target surge arrester in each phase.

[0092] This application provides a device for determining the interphase coupling capacitance of surge arresters. First, it acquires the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data for each phase of the target surge arrester. Second, based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, it constructs a first capacitive current relationship for each phase of the target surge arrester under fundamental phase-to-phase capacitance interference and a second capacitive current relationship for each phase of the target surge arrester under third harmonic phase-to-phase capacitance interference. Finally, based on the interphase coupling capacitance calculation model, it performs interphase coupling capacitance calculation processing on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data to obtain the interphase coupling capacitance data between each phase of the target surge arrester. The interphase coupling capacitance calculation model is constructed based on the first capacitive current relationship and the second capacitive current relationship. Compared with the prior art, the embodiments of this application construct a first capacitive current relationship for each phase target surge arrester under fundamental phase-to-phase capacitance interference and a second capacitive current relationship under third harmonic phase-to-phase capacitance interference. Based on the two capacitive current relationships, an interphase coupling capacitance calculation model is constructed for calculating the interphase coupling capacitance. Thus, based on the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data of each phase target surge arrester, the interphase coupling capacitance data between each phase target surge arrester is calculated through the interphase coupling capacitance calculation model, ensuring accuracy. At the same time, it is not necessary to introduce other parameters, and the calculation is simple.

[0093] According to one embodiment of this application, a storage medium is provided, the storage medium storing at least one executable instruction, which can execute the method for determining the phase-to-phase coupling capacitance of a surge arrester in any of the above method embodiments.

[0094] Based on this understanding, the technical solution of this application can be embodied in the form of a software product. This software product can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, or portable hard drive), and includes several instructions to cause a computer device (such as a personal computer, server, or network device) to execute the methods described in the various implementation scenarios of this application.

[0095] Figure 9 The diagram shows a structural schematic of a terminal according to one embodiment of the present application. The specific embodiments of the present application do not limit the specific implementation of the terminal.

[0096] like Figure 9As shown, the terminal may include: a processor 302, a communications interface 304, a memory 306, and a communications bus 308.

[0097] The processor 302, communication interface 304, and memory 306 communicate with each other via communication bus 308.

[0098] Communication interface 304 is used to communicate with other network elements such as clients or other servers.

[0099] The processor 302 is used to execute program 310, specifically the relevant steps in the embodiment of the method for determining the phase-to-phase coupling capacitance of the surge arrester of the above interface.

[0100] Specifically, program 310 may include program code that includes computer operation instructions.

[0101] Processor 302 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application. The terminal includes one or more processors, which may be processors of the same type, such as one or more CPUs; or they may be processors of different types, such as one or more CPUs and one or more ASICs.

[0102] Memory 306 is used to store program 310. Memory 306 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0103] Specifically, program 310 can be used to cause processor 302 to perform the following operations:

[0104] The effective values ​​of the fundamental voltage, the third harmonic voltage, the fundamental current, and the third harmonic current of each phase target surge arrester are obtained respectively.

[0105] Based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, a first capacitive current relationship for each phase of the target surge arrester under fundamental phase-to-phase capacitance interference and a second capacitive current relationship for each phase of the target surge arrester under third harmonic phase-to-phase capacitance interference are constructed respectively.

[0106] The effective values ​​of the fundamental voltage, the third harmonic voltage, the fundamental current, and the third harmonic current are respectively processed by the interphase coupling capacitance calculation model to calculate the interphase coupling capacitance between the target surge arresters in each phase. The interphase coupling capacitance calculation model is constructed based on the first capacitive current relationship and the second capacitive current relationship.

[0107] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages the hardware and software resources of the specific physical device containing the phase-to-phase coupling capacitors of the surge arrester, supporting the operation of information processing programs and other software and / or programs. The network communication module is used to enable communication between the various components within the storage medium, as well as communication with other hardware and software in the information processing physical device.

[0108] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0109] The methods and systems of this application may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of this application are not limited to the order specifically described above, unless otherwise specifically stated. Furthermore, in some embodiments, this application may also be implemented as a program recorded on a recording medium, the program including machine-readable instructions for implementing the methods according to this application. Thus, this application also covers recording media storing programs for performing the methods according to this application.

[0110] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0111] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for determining the interphase coupling capacitance of a surge arrester, characterized in that, include: The effective values ​​of the fundamental voltage, the third harmonic voltage, the fundamental current, and the third harmonic current of each phase target surge arrester are obtained respectively. Based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, a first capacitive current relationship for each phase of the target surge arrester under fundamental phase-to-phase capacitance interference and a second capacitive current relationship for each phase of the target surge arrester under third harmonic phase-to-phase capacitance interference are constructed respectively. The effective values ​​of the fundamental voltage, the third harmonic voltage, the fundamental current, and the third harmonic current are respectively processed by the interphase coupling capacitance calculation model to calculate the interphase coupling capacitance between the target surge arresters in each phase. The interphase coupling capacitance calculation model is constructed based on the first capacitive current relationship and the second capacitive current relationship.

2. The method according to claim 1, characterized in that, Before constructing the first capacitive current relationship and the second capacitive current relationship of the target surge arrester under the fundamental phase-to-phase capacitance interference based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, the method further includes: The phase difference data between the fundamental voltage data and the total leakage current of each phase target surge arrester, as well as the phase difference data between the third harmonic voltage data and the total leakage current, are obtained respectively. The fundamental current effective value data is orthogonally decomposed based on the phase difference between the fundamental voltage data and the total leakage current of the target surge arrester in each phase to obtain the fundamental capacitive current effective value data of the target surge arrester in each phase. The effective value data of the third harmonic current is orthogonally decomposed based on the phase difference between the third harmonic voltage data and the total leakage current of the target surge arrester in each phase, so as to obtain the effective value data of the third harmonic capacitive current of the target surge arrester in each phase.

3. The method according to claim 2, characterized in that, The construction of the first capacitive current relationship of the target surge arrester under fundamental phase-to-phase capacitance interference and the second capacitive current relationship of the target surge arrester under third harmonic phase-to-phase capacitance interference, based on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data, specifically includes: Based on vector relationships, a first capacitive current relationship is constructed between the effective value data of the fundamental capacitive current of the target surge arrester in each phase and the effective value data of the capacitive current of the surge arrester in each phase, and a second capacitive current relationship is constructed between the effective value data of the third harmonic capacitive current of the target surge arrester in each phase and the effective value data of the capacitive current of the surge arrester in each phase.

4. The method according to claim 3, characterized in that, The first capacitive current relationship is as follows: the effective value of the fundamental capacitive current of the target surge arrester in each phase is the difference between half of the effective value of the valve plate capacitor current of the current phase surge arrester and half of the sum of the effective values ​​of the coupling capacitor current of the other two phase surge arresters. The second capacitive current relationship is as follows: the effective value of the third harmonic capacitive current of the target surge arrester in each phase is the sum of the effective value of the valve plate capacitor current of the current phase surge arrester and the effective value of the coupling capacitor current of the other two phase surge arresters.

5. The method according to claim 1, characterized in that, The acquisition of the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data for each phase target surge arrester specifically includes: The operating voltage and total leakage current of each phase target surge arrester were obtained separately; The operating voltage and the total leakage current are respectively processed by signal conversion and Fourier transform to obtain the fundamental voltage RMS data, third harmonic voltage RMS data, fundamental current RMS data, and third harmonic current RMS data of the target surge arrester in each phase.

6. A device for determining the interphase coupling capacitance of a surge arrester, characterized in that, include: The acquisition module is used to acquire the fundamental voltage RMS value data, the third harmonic voltage RMS value data, the fundamental current RMS value data, and the third harmonic current RMS value data of each phase target surge arrester respectively; The construction module is used to construct, respectively, the first capacitive current relationship of the target surge arrester in each phase under the fundamental phase-to-phase capacitance interference and the second capacitive current relationship of the target surge arrester in each phase under the third harmonic phase-to-phase capacitance interference based on the fundamental voltage effective value data, the third harmonic voltage effective value data, the fundamental current effective value data, and the third harmonic current effective value data. The calculation module is used to perform interphase coupling capacitance calculation on the fundamental voltage RMS data, the third harmonic voltage RMS data, the fundamental current RMS data, and the third harmonic current RMS data based on the interphase coupling capacitance calculation model, respectively, to obtain the interphase coupling capacitance data between the target surge arresters in each phase. The interphase coupling capacitance calculation model is constructed based on the first capacitive current relationship and the second capacitive current relationship.

7. A storage medium storing at least one executable instruction, characterized in that, The executable instructions cause the processor to perform the operation corresponding to the method for determining the phase-to-phase coupling capacitance of a surge arrester as described in any one of claims 1-5.

8. An electronic device, comprising: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction, characterized in that the executable instruction causes the processor to perform the operation corresponding to the method for determining the phase-to-phase coupling capacitance of a surge arrester as described in any one of claims 1-5.

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