Power transmission line overvoltage calculation method, device and equipment and storage medium

Abstract

The invention discloses a power transmission line overvoltage calculation method, device and equipment and a storage medium, and the method comprises the steps: carrying out the iterative optimization of a collected switching-on overvoltage signal before a fault of a line, and obtaining a full-length impact response function of the line; performing linear interpolation on the impact response function of the full length of the line to establish an impact response function of a fault signal propagation distance; and calculating a fault initial overvoltage signal according to the impulse response function of the fault signal propagation distance and the propagated fault signal. According to the method, the initial form of the overvoltage waveform can be calculated, so that the overvoltage high-frequency characteristic disappearance caused by lossy transmission is avoided, and powerful support is provided for overvoltage treatment of a power system.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission network fault monitoring, and in particular to a method, device, equipment and storage medium for calculating overvoltage of a power transmission line. Background Art

[0002] When a power system experiences a fault or undergoes a switching operation, overvoltage often occurs, significantly impacting power equipment and shortening its service life. Therefore, accurate and rapid monitoring of power system overvoltage is crucial for assessing system stability and equipment reliability.

[0003] Several technical solutions exist for online overvoltage monitoring. For example, voltage transformers installed in substations can accurately measure overvoltage at low frequencies, but they suffer from significant distortion at high frequencies. This is especially true when lightning strikes cause overvoltages to originate from transmission lines. Due to the effects of the transformer's internal windings and inter-turn distributed capacitance, high-frequency overvoltages can be severely distorted.

[0004] Distributed traveling wave fault online monitoring devices installed on transmission lines can accurately collect overvoltage waveforms on the lines, thus solving this problem to a certain extent. However, according to transmission line principles, the longer the lightning overvoltage waveform propagates, the greater the energy loss and the greater the attenuation of its high-frequency characteristics, which is not conducive to subsequent overvoltage analysis and control.

[0005] Therefore, how to accurately reflect the line overvoltage status at the moment of fault occurrence to facilitate overvoltage analysis and control is a technical problem that urgently needs to be solved. Summary of the Invention

[0006] The main purpose of the present invention is to provide a method, device, equipment and storage medium for calculating overvoltage of transmission lines, which can effectively solve the problem of disappearance of high-frequency characteristics of overvoltage caused by lossy transmission of the line, realize accurate restoration of the initial overvoltage characteristics of the fault, and provide strong support for overvoltage control of the power system.

[0007] In a first aspect, the present application provides a method for detecting overvoltage in a transmission line, wherein the method comprises the steps of:

[0008] Iteratively optimize the collected overvoltage signal before the line fault and obtain the impulse response function of the entire line length;

[0009] performing linear interpolation on the impulse response function of the entire length of the line to establish an impulse response function of the fault signal propagation distance;

[0010] The initial overvoltage signal of the fault is calculated based on the impulse response function of the fault signal propagation distance and the propagated fault signal.

[0011] In conjunction with the first aspect above, as an optional implementation, based on first detection equipment and second detection equipment installed at both ends of the line, the first detection equipment is used to collect a first overvoltage signal generated during a line closing operation, and the second detection equipment is used to collect a second overvoltage signal at the location where the first overvoltage signal propagates to the second device;

[0012] Performing convolution processing on the first overvoltage signal and the second overvoltage signal to analyze the relationship between the line and the signal propagation;

[0013] Based on the relationship, the difference between the actual signal and the estimated signal is calculated, and a loss function of the impulse response of the entire line length is constructed according to the established regularization term;

[0014] The loss function is optimized using the gradient descent method to obtain the line full-length impulse response function.

[0015] In combination with the first aspect above, as an optional implementation method, a relationship between line and signal propagation is established, which is expressed as follows:

[0016] Where x1 is the first overvoltage signal generated by the first detection device when the line is closed, and y1 is the signal transmitted from x1 to the other end of the line and collected by the second detection device. is the impulse response function based on the full length of the line L1, * is the convolution operation, N is the signal length, n is the nth point in y1, and k is the summation control parameter;

[0017] Establishing the loss function in, Expressed as the difference between the actual signal and the estimated signal, is the regularization term, M is The length of . λ is the regularization parameter;

[0018] According to the formula:

[0019]

[0020] The loss function is optimized to obtain the full-length impulse response function of the line, where t is the number of iterations, m is the time step of the current iteration, and η is the learning rate, which represents the step size of each iteration during the gradient descent solution process.

[0021] In combination with the first aspect above, as an optional implementation method, determine whether the absolute value of the change in the loss function is less than a first threshold, whether the modulus of the differential of the loss function is less than a second threshold, and whether the number of iterations exceeds a maximum number of iterations;

[0022] If any of the above conditions is met, stop optimizing the loss function.

[0023] In combination with the first aspect above, as an optional implementation method, an impulse response function of the fault signal propagation distance is established, and its expression is:

[0024] Where α is the attenuation coefficient, δ n is the decimal place of L2n / L1, L1 is the total length of the line, L2 is the propagation distance of the fault signal, and n is The nth point in To round down, To round up, is the impulse response of the entire line length, where ω0 is the center frequency of the fault signal, R is the line resistance per unit length, L is the line inductance per unit length, G is the line conductance per unit length, and C is the line capacitance per unit length.

[0025] In combination with the first aspect above, as an optional implementation, according to the formula: Calculate the propagated fault signal, where x2 is the initial signal generated by the fault, is the impulse response function of the fault signal propagation distance;

[0026] Performing Fourier transform on the propagated fault signal, we obtain:

[0027]

[0028] According to the formula: Calculate the initial overvoltage signal of the fault.

[0029] In a second aspect, the present application provides a transmission line overvoltage detection device, the device comprising:

[0030] An optimization module is used to iteratively optimize the collected pre-fault closing overvoltage signal of the line to obtain the impulse response function of the entire line length;

[0031] a processing module, configured to perform linear interpolation on the impulse response function of the entire length of the line to establish an impulse response function of the fault signal propagation distance;

[0032] The calculation module is used to calculate the initial overvoltage signal of the fault according to the impulse response function of the fault signal propagation distance and the propagated fault signal.

[0033] In conjunction with the second aspect above, as an optional implementation, the optimization module is further configured to, based on a first detection device and a second detection device installed at each end of the line, use the first detection device to collect a first overvoltage signal generated during a line closing operation, and use the second detection device to collect a second overvoltage signal at a location where the first overvoltage signal is transmitted to the second device;

[0034] Performing convolution processing on the first overvoltage signal and the second overvoltage signal to analyze the relationship between the line and the signal propagation;

[0035] Based on the relationship, the difference between the actual signal and the estimated signal is calculated, and a loss function of the impulse response of the entire line length is constructed according to the established regularization term;

[0036] The loss function is optimized using the gradient descent method to obtain the line full-length impulse response function.

[0037] In a third aspect, the present application further provides an electronic device comprising: a processor; and a memory, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the processor, the method described in any one of the first aspects is implemented.

[0038] In a fourth aspect, the present application further provides a computer-readable storage medium storing computer program instructions, which, when executed by a computer, enables the computer to execute any one of the methods described in the first aspect.

[0039] The present application provides a method, apparatus, device, and storage medium for calculating overvoltage on a transmission line. The method comprises the following steps: iteratively optimizing a pre-fault closing overvoltage signal collected on the line to obtain an impulse response function for the entire length of the line; linearly interpolating the impulse response function for the entire length of the line to establish an impulse response function for the propagation distance of the fault signal; and calculating the initial overvoltage signal of the fault based on the impulse response function for the propagation distance of the fault signal and the propagated fault signal. The present application can calculate the initial form of the overvoltage waveform, thereby avoiding the disappearance of the high-frequency characteristics of the overvoltage due to lossy transmission, providing strong support for overvoltage control in power systems.

[0040] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0042] Figure 1This is a flow chart of a method for calculating overvoltage on a transmission line provided in an embodiment of the present application;

[0043] Figure 2 A schematic diagram of a transmission line overvoltage calculation device provided in an embodiment of the present application;

[0044] Figure 3 Schematic diagram of the closing process and fault process provided in the embodiment of the present application;

[0045] Figure 4 A schematic diagram of an electronic device provided in an embodiment of the present application;

[0046] Figure 5 A schematic diagram of a computer-readable program medium provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, like numbers in different figures represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present invention, as detailed in the appended claims.

[0048] Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. Some of the blocks shown in the drawings are functional entities that do not necessarily correspond to physically or logically separate entities.

[0049] The embodiments of the present application are further described in detail below with reference to the accompanying drawings.

[0050] Reference Figure 1 , Figure 1 FIG. 1 is a flow chart of a method for detecting overvoltage in a transmission line according to the present invention. Figure 1 As shown, the method includes the steps of:

[0051] Step S101: Iteratively optimize the collected pre-fault closing overvoltage signal of the line to obtain the impulse response function of the entire line length.

[0052] Specifically, based on a first detection device and a second detection device installed at each end of the line, the first detection device is used to collect a first overvoltage signal generated during the line closing operation, and the second detection device is used to collect a second overvoltage signal at the second device where the first overvoltage signal is transmitted;

[0053] Performing convolution processing on the first overvoltage signal and the second overvoltage signal to analyze the relationship between the line and the signal propagation;

[0054] Based on the relationship, the difference between the actual signal and the estimated signal is calculated, and a loss function of the impulse response of the entire line length is constructed according to the established regularization term;

[0055] The loss function is optimized using the gradient descent method to obtain the line full-length impulse response function.

[0056] The relationship between the established line and the propagation of the signal is expressed as follows:

[0057] Where x1 is the first overvoltage signal generated by the first detection device when the line is closed, and y1 is the signal transmitted from x1 to the other end of the line and collected by the second detection device. is the impulse response function based on the full length of the line L1, * is the convolution operation, N is the signal length, n is the nth point in y1, and k is the summation control parameter;

[0058] Establishing the loss function in, Expressed as the difference between the actual signal and the estimated signal, is the regularization term, M is The length of . λ is the regularization parameter;

[0059] According to the formula:

[0060]

[0061] The loss function is optimized to obtain the full-length impulse response function of the line, where t is the number of iterations, m is the time step of the current iteration, and η is the learning rate, which represents the step size of each iteration during the gradient descent solution process.

[0062] To facilitate understanding of the specific instructions, before the fault, the impulse response based on the full length of the line L1 is calculated. According to transmission line theory, when overvoltage signals propagate along a line, they are affected by the line's distributed parameters, resulting in attenuation, dispersion, and distortion. Because it's difficult to establish an accurate time-domain mathematical model for this phenomenon, namely, a unit impulse response function, we first assume that one device is installed at each end of the line (referred to as the first device and the second device, respectively) and perform an indirect calculation using the waveform generated by line closing. This involves the following four sub-steps.

[0063] 1.1 Establish the propagation relationship of closing waveform

[0064] Assume that the overvoltage signal generated by the line closing operation originates at the substation where the first device is located and is captured by the first device, denoted as signal x1. The signal then propagates to the other end and is collected by the second device, denoted as signal y1. According to signal system principles, ideally, the influence of the line on signal propagation can be expressed in the time domain as a unit impulse response function, as shown in Equation (e1).

[0065]

[0066] in,

[0067]

[0068] Here, n can be understood as the nth point in the input signal, and k is a summation control parameter whose value range is (0, N+1). is the impulse response function (discrete function) based on the full length of the line L1.

[0069] 1.2 Establishing the loss function

[0070]

[0071] in,

[0072] In formula (e2), e[n] represents the difference between the actual signal and the estimated signal (wherein the actual signal is the signal y1 actually measured by the second device. The estimated signal is a hypothetical line model To process the known signal x1 of the first device, estimate the signal that the second device may collect). The purpose of this item is to find the optimal Minimize the difference so that the desired It can best simulate the impact of actual lines on signals.

[0073] In formula (e2), is the regularization term. M is The length of the function. λ is the regularization parameter. Introducing a regularization term into the loss function can limit noise in the data and improve the model's generalization ability. The value of λ is generally negatively correlated with the sample size. A good rule of thumb is λ = 1 / C, where C is the number of samples.

[0074] According to formula (e2), the differential form of the loss function is derived as formula (e4).

[0075]

[0076] 1.3 Iterate each time step m in the impulse response function.

[0077] The meaning of the differential loss function of formula (e4) represents the difference between The value of is the degree of change of the loss function value itself. Therefore, according to the principle of gradient descent, iterate according to formula (e5) The loss function can be gradually reduced until it is optimal.

[0078]

[0079] The equation is (e5), where t is the number of iterations, m is the time step of the current iteration, and η is the learning rate, which represents the step size of each iteration during the gradient descent solution. It can be set to 0.01–0.1 based on experience or as an adaptive parameter using the Adagrad algorithm.

[0080] 1.4 Execute iterations until any of the following conditions (e6-e8) are met. It can be understood that it is determined whether the absolute value of the change in the loss function is less than a first threshold, whether the modulus of the differential of the loss function is less than a second threshold, and whether the number of iterations exceeds the maximum number of iterations;

[0081] If any of the above conditions is met, stop optimizing the loss function.

[0082] a) The absolute value of the change in the loss function is less than a certain threshold ε1,

[0083] b) The modulus of the differential of the loss function is less than a certain threshold ε2,

[0084] c) The number of iterations exceeds the maximum number of iterations T max , (e8) = t ≥ T max .

[0085] Step S102: performing linear interpolation on the impulse response function of the entire line length to establish an impulse response function of the fault signal propagation distance.

[0086] After the fault, calculate the impulse response based on the actual propagation distance L2 After a line fault occurs, to obtain the initial overvoltage waveform, we need to know the propagation distance of the waveform and the signal collected by the corresponding device. Once generated, the overvoltage signal propagates simultaneously to both sides of the line, and either side can be used. Therefore, this article uses the second device as an example. That is, the distance the signal propagates from the fault point to the second device is considered to be L2. The signal collected by the second device is y2. Figure 3 the lower half.

[0087] The propagation of overvoltage signals on transmission lines is lossy. The longer the line, the greater the energy loss. In practice, due to the corona effect of hardware, the skin effect of conductors, and Joule heating effects, the amplitude attenuation effect during signal propagation is more significant than the dispersion effect. Therefore, to simplify the calculation, only the amplitude attenuation and the delay effect caused by line length changes are considered. Based on the unit impulse response function of the full line length L1, linear interpolation is used to establish the unit impulse response function based on the fault signal propagation distance L2. As shown in formula (e9).

[0088] Where α is the attenuation coefficient, δ n is the decimal place of L2n / L1, L1 is the total length of the line, L2 is the propagation distance of the fault signal, and n is The nth point in To round down, To round up, is the impulse response of the entire line length, where ω0 is the center frequency of the fault signal, R is the line resistance per unit length, L is the line inductance per unit length, G is the line conductance per unit length, and C is the line capacitance per unit length.

[0089] In addition, the center frequency formula (e12) is calculated, Where ω0 is the center frequency, H is the frequency domain function of the signal after fast Fourier transform, f0 is the signal sampling rate, Δf is the frequency domain resolution, Δf = f0 / N, and f is the frequency variable.

[0090] Step S103: Calculate the initial overvoltage signal of the fault according to the impulse response function of the fault signal propagation distance and the propagated fault signal.

[0091] Specifically, the fault initial overvoltage waveform x2 is calculated.

[0092] From formula (e1), it can be seen that the initial signal x2 generated by the fault becomes y2 after propagating a distance of L2, and also satisfies the following relationship (e13).

[0093] Perform Fourier transform on (e13) and we get According to the formula: Calculate the initial overvoltage signal of the fault.

[0094] Reference Figure 2 , Figure 2 FIG. 1 is a schematic diagram of a transmission line overvoltage detection device provided by the present invention, as shown in FIG. Figure 2 As shown, the device includes:

[0095] Optimization module 201: It is used to iteratively optimize the collected pre-fault closing overvoltage signal of the line to obtain the impulse response function of the entire line length.

[0096] The processing module 202 is configured to perform linear interpolation on the impulse response function of the entire length of the line to establish an impulse response function of the fault signal propagation distance.

[0097] Calculation module 203: used to calculate the initial overvoltage signal of the fault according to the impulse response function of the fault signal propagation distance and the propagated fault signal.

[0098] Furthermore, in one possible embodiment, the optimization module is further configured to, based on first detection equipment and second detection equipment installed at both ends of the line, use the first detection equipment to collect a first overvoltage signal generated during a line closing operation, and use the second detection equipment to collect a second overvoltage signal generated when the first overvoltage signal propagates to the second device;

[0099] Performing convolution processing on the first overvoltage signal and the second overvoltage signal to analyze the relationship between the line and the signal propagation;

[0100] Based on the relationship, the difference between the actual signal and the estimated signal is calculated, and a loss function of the impulse response of the entire line length is constructed according to the established regularization term;

[0101] The loss function is optimized using the gradient descent method to obtain the line full-length impulse response function.

[0102] Furthermore, in a possible implementation, the processing module is further configured to establish a propagation relationship between the line and the signal, which is expressed as follows:

[0103] Where x1 is the first overvoltage signal generated by the first detection device when the line is closed, and y1 is the signal transmitted from x1 to the other end of the line and collected by the second detection device. is the impulse response function based on the full length of the line L1, * is the convolution operation, N is the signal length, n is the nth point in y1, and k is the summation control parameter;

[0104] Establishing the loss function

[0105] in, Expressed as the difference between the actual signal and the estimated signal, is the regularization term, M is The length of . λ is the regularization parameter, m is the step time;

[0106] According to the formula:

[0107]

[0108] The loss function is optimized to obtain the full-length impulse response function of the line, where t is the number of iterations, m is the time step of the current iteration, and η is the learning rate, which represents the step size of each iteration during the gradient descent solution process.

[0109] Furthermore, in a possible implementation, the processing module is further configured to determine whether the absolute value of the change in the loss function is less than a first threshold, whether the modulus of the differential of the loss function is less than a second threshold, and whether the number of iterations exceeds a maximum number of iterations;

[0110] If any of the above conditions is met, stop optimizing the loss function.

[0111] Furthermore, in a possible implementation, the processing module is further configured to establish an impulse response function of the fault signal propagation distance, which is expressed as follows:

[0112] Where α is the attenuation coefficient, δ n is the decimal place of L2n / L1, L1 is the total length of the line, L2 is the propagation distance of the fault signal, and n is The nth point in To round down, To round up, is the impulse response of the entire line length, where ω0 is the center frequency of the fault signal, R is the line resistance per unit length, L is the line inductance per unit length, G is the line conductance per unit length, and C is the line capacitance per unit length.

[0113] Furthermore, in a possible implementation manner, the calculation module is further configured to calculate the value according to the formula: Calculate the propagated fault signal, where x2 is the initial signal generated by the fault, is the impulse response function of the fault signal propagation distance;

[0114] Performing Fourier transform on the propagated fault signal, we obtain:

[0115]

[0116] According to the formula: Calculate the initial overvoltage signal of the fault.

[0117] Reference Figure 3 , Figure 3 The figure shows the closing process and fault process provided by the present invention. Figure 3 As shown:

[0118] A device is installed at each end of the transmission line to obtain the line impulse response function by collecting the overvoltage traveling wave before the closing of the line fault. After a fault occurs, the overvoltage signal generated by the fault is collected in real time to establish an impulse response function based on the actual propagation distance. Therefore, the initial signal is obtained by using deconvolution to accurately reflect the line overvoltage state at the moment of fault occurrence, providing strong support for overvoltage control of the power system.

[0119] When overvoltage signals propagate along a line, they are affected by the line's distributed parameters, resulting in attenuation, dispersion, and distortion. Because it's difficult to establish an accurate time-domain mathematical model for these phenomena, namely, a unit impulse response function, we first assume that one device is installed at each end of the line (referred to as the first device and the second device, respectively). We then perform an indirect calculation using the waveform generated by line closing (see step S101 for details).

[0120] Assume that the overvoltage signal generated by the line closing operation is generated at the substation where the first device is located and is captured by the first device, recorded as signal x1. The signal then propagates to the other end and is collected by the second device, recorded as signal y1.

[0121] After a line fault occurs, to obtain the initial overvoltage waveform, we need to determine the propagation distance of the waveform and the signal collected by the corresponding device. Once generated, the overvoltage signal propagates simultaneously to both sides of the line, and either side can be used. Therefore, this application uses the second device as an example. Specifically, consider the distance L2 from the fault point to the second device. The signal collected by the second device is y2. Here, the total line length is L1, and the distance L2 from the fault point to the second device is L1.

[0122] In summary, the present application can effectively solve the problem of disappearance of high-frequency characteristics of overvoltage caused by lossy transmission, and accurately restore the initial overvoltage characteristics of the fault; and can reconstruct the overvoltage signal generated by any fault point on the line, and has a wider range of applications.

[0123] Refer to the following Figure 4 An electronic device 400 according to this embodiment of the present invention will be described. Figure 4 The electronic device 400 shown is merely an example and should not limit the functions and scope of use of the embodiments of the present invention.

[0124] like Figure 4 As shown, electronic device 400 is implemented as a general-purpose computing device. Components of electronic device 400 may include, but are not limited to, at least one processing unit 410, at least one storage unit 420, and a bus 430 connecting various system components (including storage unit 420 and processing unit 410).

[0125] The storage unit stores program codes, which can be executed by the processing unit 410, so that the processing unit 410 performs the steps according to various exemplary embodiments of the present invention described in the above “Example Method” section of this specification.

[0126] The storage unit 420 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 421 and / or a cache memory unit 422 , and may further include a read-only memory unit (ROM) 423 .

[0127] The storage unit 420 may also include a program / utility 424 having a set (at least one) of program modules 425, such program modules 425 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0128] Bus 430 may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0129] The electronic device 400 may also communicate with one or more external devices (e.g., a keyboard, a pointing device, a Bluetooth device, etc.), one or more devices that enable a user to interact with the electronic device 400, and / or any device that enables the electronic device 400 to communicate with one or more other computing devices (e.g., a router, a modem, etc.). Such communication may occur via an input / output (I / O) interface 450. Furthermore, the electronic device 400 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network such as the Internet) via a network adapter 460. As shown, the network adapter 460 communicates with other modules of the electronic device 400 via a bus 430. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 400, including but not limited to microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0130] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solution according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the embodiments of the present disclosure.

[0131] According to the solution of the present disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the above-mentioned method of this specification is stored. In some possible implementations, various aspects of the present invention may also be implemented in the form of a program product, which includes program code. When the program product is executed on a terminal device, the program code is used to cause the terminal device to perform the steps according to various exemplary embodiments of the present invention described in the "Exemplary Methods" section of this specification.

[0132] refer to Figure 5 As shown, a program product 500 for implementing the above method according to an embodiment of the present invention is described. The program product 500 may be a portable compact disc read-only memory (CD-ROM) and include program code, and may be run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, a readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0133] The program product may be implemented in any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples (a 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 thereof.

[0134] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0135] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0136] The program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, and the like, as well as 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 stand-alone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device may be connected to the user computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0137] Furthermore, the above-described figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention and are not intended to be limiting. It is readily understood that the processes illustrated in the above-described figures do not indicate or limit the temporal order of these processes. Furthermore, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0138] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

[0139] 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 flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, 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 flowcharts and / or block diagrams. 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.

Claims

1. A method for calculating overvoltage of a transmission line, characterized in that: include: Iteratively optimize the collected overvoltage signal before the line fault and obtain the impulse response function of the entire line length; performing linear interpolation on the impulse response function of the entire length of the line to establish an impulse response function of the fault signal propagation distance; The initial overvoltage signal of the fault is calculated based on the impulse response function of the fault signal propagation distance and the propagated fault signal.

2. The method according to claim 1, characterized in that The iterative optimization of the collected pre-fault closing overvoltage signal of the line to obtain the impulse response function of the entire line length includes: Based on the first detection device and the second detection device installed at both ends of the line, the first detection device is used to collect a first overvoltage signal generated during the line closing operation, and the second detection device is used to collect a second overvoltage signal at the second device where the first overvoltage signal is transmitted; performing convolution processing on the first overvoltage signal and the second overvoltage signal to analyze the relationship between the line and the signal propagation; Based on the relationship, the difference between the actual signal and the estimated signal is calculated, and a loss function of the impulse response of the entire line length is constructed according to the established regularization term; The loss function is optimized using the gradient descent method to obtain the line full-length impulse response function.

3. The method according to claim 2, characterized in that include: The relationship between line and signal propagation is established, and its expression is: Where x1 is the first overvoltage signal generated by the first detection device when the line is closed, and y1 is the signal transmitted from x1 to the other end of the line and collected by the second detection device. is the impulse response function based on the full length of the line L1, * is the convolution operation, N is the signal length, n is the nth point in y1, and k is the summation control parameter; Establishing the loss function in, Expressed as the difference between the actual signal and the estimated signal, is the regularization term, M is The length of . λ is the regularization parameter, m is the step time; According to the formula: The loss function is optimized to obtain the full-length impulse response function of the line, where t is the number of iterations, m is the time step of the current iteration, and η is the learning rate, which represents the step size of each iteration during the gradient descent solution process.

4. The method according to claim 3, characterized in that Also includes: Determine whether the absolute value of the change in the loss function is less than a first threshold, whether the modulus of the differential of the loss function is less than a second threshold, and whether the number of iterations exceeds a maximum number of iterations; If any of the above conditions is met, stop optimizing the loss function.

5. The method according to claim 1, wherein The linear interpolation of the impulse response function of the entire length of the line to establish the impulse response function of the fault signal propagation distance includes: The impulse response function of the fault signal propagation distance is established, and its expression is: Where α is the attenuation coefficient, δ n is the decimal place of L2n / L1, L1 is the total length of the line, L2 is the propagation distance of the fault signal, and n is The nth point in To round down, To round up, is the impulse response of the entire line length, where ω0 is the center frequency of the fault signal, R is the line resistance per unit length, L is the line inductance per unit length, G is the line conductance per unit length, and C is the line capacitance per unit length.

6. The method according to claim 1, characterized in that The calculating of the fault initial overvoltage signal according to the impulse response function of the fault signal propagation distance and the propagated fault signal includes: According to the formula: Calculate the propagated fault signal, where x2 is the initial signal generated by the fault, is the impulse response function of the fault signal propagation distance; Performing Fourier transform on the propagated fault signal, we obtain: According to the formula: Calculate the initial overvoltage signal of the fault. -1 is the inverse Fourier transform.

7. A transmission line overvoltage calculation device, characterized in that: include: An optimization module is used to iteratively optimize the collected pre-fault closing overvoltage signal of the line to obtain the impulse response function of the entire line length; a processing module, configured to perform linear interpolation on the impulse response function of the entire length of the line to establish an impulse response function of the fault signal propagation distance; The calculation module is used to calculate the initial overvoltage signal of the fault according to the impulse response function of the fault signal propagation distance and the propagated fault signal.

8. The device according to claim 7, characterized in that: The optimization module is further configured to, based on a first detection device and a second detection device installed at each end of the line, use the first detection device to collect a first overvoltage signal generated during a line closing operation, and use the second detection device to collect a second overvoltage signal where the first overvoltage signal propagates to the second device; performing convolution processing on the first overvoltage signal and the second overvoltage signal to analyze the relationship between the line and the signal propagation; Based on the relationship, the difference between the actual signal and the estimated signal is calculated, and a loss function of the impulse response of the entire line length is constructed according to the established regularization term; The loss function is optimized using the gradient descent method to obtain the line full-length impulse response function.

9. An electronic device, characterized in that: The electronic device comprises: processor; A memory having computer-readable instructions stored thereon, wherein when the computer-readable instructions are executed by the processor, the method according to any one of claims 1 to 6 is implemented.

10. A computer-readable storage medium, characterized in that The computer program instructions are stored therein, and when the computer program instructions are executed by a computer, the computer is caused to execute the method according to any one of claims 1 to 6.

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