Wave recording type lightning arrester on-line monitoring method and device

Abstract

The invention provides an online monitoring method and device for a wave-recording lightning arrester, and belongs to the technical field of electrical safety, and the method comprises the steps: carrying out the calculation of three-phase basic voltage data of a three-phase bus of the wave-recording lightning arrester based on a fast Fourier transform algorithm, and obtaining a fundamental voltage amplitude and a first phase; based on the fundamental wave voltage amplitude and the three-phase fundamental wave leakage current data of the three-phase bus of the wave recording type lightning arrester, a resistive fundamental wave current amplitude and a second phase are obtained through calculation; the number of the first phases and the number of the second phases are respectively three. And calculating a first difference value between each first phase and the corresponding second phase, processing the first difference values to obtain a weighted first difference value, and determining the operation state of the lightning arrester based on a subordination relationship between the weighted first difference value and a preset numerical value interval. According to the invention, the operation state of the wave recording type lightning arrester can be comprehensively and accurately monitored, and the safety and reliability of a power system are improved.

Description

Technical Field

[0001] The present invention belongs to the field of electrical safety technology, and more specifically, relates to an online monitoring method and device for a wave recording type lightning arrester. Background Art

[0002] As a key device to ensure the safe and stable operation of the power system, the performance status of the lightning arrester is directly related to the reliable operation of the power equipment and the safety of personnel. Wave recording lightning arresters have been widely used in modern power systems because they can record the waveform information of the electrical transient process, providing rich data support for accurate analysis of the operating status of the lightning arrester. Traditional lightning arrester monitoring methods have many limitations. For example, offline detection requires power outages, which not only affects the normal power supply of the power system and reduces the reliability of power supply, but also has a long detection cycle, making it difficult to grasp the operating status of the lightning arrester in real time and unable to detect potential fault hazards in time. Summary of the invention

[0003] The purpose of the present invention is to provide an online monitoring method and device for a wave-recording type lightning arrester, so as to comprehensively and accurately monitor the operating status of the wave-recording type lightning arrester, improve the safety and reliability of the power system, reduce the risk of power outages caused by lightning arrester failures, and reduce economic losses.

[0004] A first aspect of the embodiments of the present disclosure provides an online monitoring method for a wave recording type lightning arrester, comprising: The three-phase basic voltage data of the three-phase busbar of the recording type lightning arrester is calculated based on the fast Fourier transform algorithm to obtain the fundamental voltage amplitude and the first phase; Based on the fundamental voltage amplitude and the three-phase fundamental leakage current data of the three-phase busbar of the recording type lightning arrester, the resistive fundamental current amplitude and the second phase are calculated; the first phase and the second phase have three each; A first difference between each first phase and the corresponding second phase is calculated, the first difference is processed to obtain a weighted first difference, and the operating state of the arrester is determined based on a subordinate relationship between the weighted first difference and a preset numerical range.

[0005] A second aspect of the embodiments of the present disclosure provides an online monitoring device for a wave recording type lightning arrester, comprising: A first calculation module is used to calculate the three-phase basic voltage data of the three-phase bus of the recording type lightning arrester based on a fast Fourier transform algorithm to obtain a fundamental voltage amplitude and a first phase; A second calculation module is used to calculate the resistive fundamental current amplitude and the second phase based on the fundamental voltage amplitude and the three-phase fundamental leakage current data of the three-phase busbar of the recording type lightning arrester; the first phase and the second phase have three each; The state determination module is used to calculate the first difference between each first phase and the corresponding second phase, process the first difference to obtain a weighted first difference, and determine the operating state of the lightning arrester based on the subordinate relationship between the weighted first difference and a preset numerical range.

[0006] According to a third aspect of an embodiment of the present disclosure, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of the above-mentioned method for online monitoring of a wave-recording type lightning arrester when executing the computer program.

[0007] According to a fourth aspect of the embodiments of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned method for online monitoring of a wave-recording type lightning arrester are implemented.

[0008] The beneficial effects of the on-line monitoring method and device of the wave recording type lightning arrester provided by the embodiments of the present disclosure are: BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0009] Figure 1 A schematic diagram of a flow chart of an online monitoring method for a wave recording type lightning arrester provided in an embodiment of the present disclosure; Figure 2 A structural block diagram of an on-line monitoring device for a wave recording type lightning arrester provided in an embodiment of the present disclosure; Figure 3 A schematic block diagram of an electronic device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0010] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present disclosure. However, it should be clear to those skilled in the art that the present disclosure may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obstructing the description of the present disclosure with unnecessary details.

[0011] In order to make the purpose, technical solutions and advantages of the present disclosure more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0012] Please refer to Figure 1 , Figure 1 A schematic flow chart of an online monitoring method for a wave recording type lightning arrester provided in an embodiment of the present disclosure, the method comprising: S101: Calculate the three-phase basic voltage data of the three-phase busbar of the recording type lightning arrester based on the fast Fourier transform algorithm to obtain the fundamental voltage amplitude and the first phase.

[0013] In this embodiment, Fourier transform is a mathematical tool for converting time domain signals into frequency domain signals. Its basic idea is that any periodic function can be expressed as the sum of a series of sine and cosine functions. However, the traditional Fourier transform has a high computational complexity, and when the amount of data processed is large, the amount of calculation will be very large. Fast Fourier transform (FastFourier Transform, FFT) is an algorithm for efficiently calculating discrete Fourier transform, which can greatly reduce the amount of calculation. The FFT algorithm can quickly extract the frequency components of the three-phase basic voltage data signal, including the fundamental frequency and each harmonic frequency.

[0014] The three-phase busbars of the wave recording type lightning arrester correspond to the A phase, B phase and C phase of the three-phase AC power. The voltage and current transmitted by the three-phase busbar are the main electrical quantities of the three-phase AC system. There is a specific relationship between the voltage and current in amplitude, frequency and phase. For example, in a symmetrical three-phase system, the three-phase voltage amplitude is equal, the frequency is the same, and the phase difference is 120°.

[0015] The three-phase basic voltage data contains information about the change of the three-phase bus voltage over time, usually in the form of a discrete time series. For example, the three-phase bus voltage is sampled at regular intervals to obtain a series of voltage sampling values. These data can be used to analyze the effective value, peak value, frequency, phase and other parameters of the three-phase voltage.

[0016] In AC signals, in addition to the fundamental frequency component, there may also be harmonic components. The fundamental wave refers to the sine wave component with the same power frequency (in the power system, the fundamental frequency is generally 50Hz or 60Hz). The fundamental voltage amplitude is the voltage amplitude corresponding to the fundamental frequency obtained after the three-phase basic voltage data is processed by the FFT algorithm.

[0017] The first phase refers to the initial phase of the fundamental voltage of a phase (such as phase A) in the three-phase basic voltage data. After the frequency domain information of the fundamental voltage is obtained through the FFT algorithm, its phase information can be determined. The first phase can be the phase of phase A, phase B or phase C in the basic voltage data.

[0018] S102: Calculate the resistive fundamental current amplitude and the second phase based on the fundamental voltage amplitude and the three-phase fundamental leakage current data of the three-phase busbar of the wave recording type lightning arrester; the first phase and the second phase have three each.

[0019] In this embodiment, the wave recording type arrester can record the leakage current data during operation. In the AC system, the leakage current also contains the fundamental wave and each harmonic component. For the three-phase system, there are fundamental wave leakage current data of phase A, phase B and phase C respectively. These data reflect the change of the magnitude of the leakage current at the fundamental wave frequency over time during the operation of the three-phase system, and are also an important basis for evaluating the performance of the arrester and the insulation condition of the system.

[0020] In the leakage current of the arrester, according to the phase relationship between current and voltage, the leakage current can be decomposed into capacitive current and resistive current. Capacitive current is mainly caused by the capacitive characteristics of the arrester, while resistive current is related to factors such as the nonlinear resistance characteristics of the arrester and the active power loss of the system. The resistive fundamental current amplitude refers to the amplitude of the fundamental current component with the same phase (or approximately the same phase) as the voltage decomposed from the three-phase fundamental leakage current data. By calculating the resistive fundamental current amplitude, the aging degree and moisture condition of the arrester, which have an important impact on the safe operation of the system, can be evaluated. For example, when the arrester is damp or aged, the resistive fundamental current amplitude will increase.

[0021] In a three-phase AC system, the voltage signal is three-phase, and the voltage of each phase has its own phase. The first phase here refers to the phase of the three-phase bus fundamental voltage. For a three-phase system, there are fundamental voltage phases of phase A, phase B, and phase C. These three phases are used to describe the starting position relationship of the three-phase voltage on the time axis. For example, if the fundamental voltage expression of phase A is , B phase is , C phase is .

[0022] The second phase refers to the phase of the three-phase fundamental leakage current. In a three-phase system, there are phases of the fundamental leakage current of phase A, phase B, and phase C. These phases are related to the phase of the three-phase fundamental voltage and the electrical characteristics of the arrester (such as capacitance, resistance, etc.). They are used to describe the starting position relationship of the three-phase fundamental leakage current on the time axis, and play a key role in analyzing the working state of the arrester, the leakage current characteristics, and the phase relationship with the voltage.

[0023] In this embodiment, the fundamental voltage amplitude is one of the key factors for calculating the resistive fundamental current amplitude. According to the fundamental voltage amplitude combined with the equivalent impedance parameters (resistance R and reactance X) of the arrester, the resistive fundamental current amplitude can be calculated. The three-phase fundamental leakage current data contains the magnitude and phase information of the current. By analyzing the three-phase fundamental leakage current data, the resistive current component can be separated. Because in the actual three-phase power system, due to the differences in the three-phase voltage and the characteristics of the arrester itself, the three-phase leakage current will also be different. By measuring the three-phase fundamental leakage current data, the working state of the arrester in the three-phase system can be fully understood.

[0024] The second phase refers to the phase of the three-phase fundamental leakage current. For the arrester, the working state of the arrester can be determined by calculating the second phase of the three-phase fundamental leakage current and comparing it with the first phase of the three-phase fundamental voltage. For example, if the phase of the leakage current deviates greatly from the phase of the voltage, it means that there is a problem with the capacitor or resistor components inside the arrester, such as moisture, aging, etc., which causes changes in its electrical performance. At the same time, by analyzing the difference in the second phase between the three phases, potential problems such as three-phase imbalance can also be discovered.

[0025] S103: Calculate the first difference between each first phase and the corresponding second phase, process the first difference to obtain a weighted first difference, and determine the operating state of the arrester based on a subordinate relationship between the weighted first difference and a preset numerical range.

[0026] In AC circuits, the phase difference between voltage and current is a key parameter. For the arrester, the difference between the first phase of the three-phase fundamental voltage and the second phase of the three-phase fundamental leakage current (the first difference) reflects the time lag or lead relationship between the voltage and the leakage current. From a physical point of view, this difference is related to the capacitance and resistance characteristics inside the arrester. In an actual three-phase power system, the load between the three phases may be unbalanced, and the operation of the arrester in the three phases may also be different. The weighting of the first difference is to more reasonably integrate the three-phase situation to evaluate the overall state of the arrester. The weights of different phases can be determined according to the environment and the characteristics of the system (such as the importance level of the three phases, temperature, humidity, number of lightning strikes, etc.).

[0027] In this embodiment, through a large number of experiments and field operation experience, the range of the weighted first difference under different operating conditions can be determined. For example, when the arrester operates normally, the weighted first difference can be within a smaller range. This is because under normal circumstances, the capacitance and resistance characteristics of the arrester are relatively stable, and the phase difference of the voltage and leakage current is also relatively stable. However, when the arrester is damp, aged, or has internal component damage, its capacitance or resistance characteristics will change, causing the phase difference (weighted first difference) to exceed the normal range.

[0028] It can be concluded from the above that the present disclosure can accurately and quickly extract the fundamental voltage amplitude and the first phase by processing the three-phase basic voltage data of the three-phase busbar of the recording type lightning arrester using the fast Fourier transform (FFT) algorithm. Further, in combination with the three-phase fundamental leakage current data, the resistive fundamental current amplitude and the second phase can be calculated to obtain more comprehensive lightning arrester operation information. After calculating the first difference between each first phase and the corresponding second phase, a weighted first difference that can comprehensively reflect the phase relationship between the three-phase voltage and current can be obtained by weighting the first difference. The subordinate relationship between this difference and the preset numerical interval provides a reliable basis for judging the operating state of the lightning arrester. Compared with the traditional evaluation method, the monitoring method provided by the present disclosure not only takes into account the amplitude of the voltage and current, but also fully considers their phase relationship, so that the operating state of the lightning arrester can be more accurately evaluated.

[0029] In one embodiment of the present disclosure, processing the first difference to obtain a weighted first difference includes: Performing weighted processing on the first difference according to the first weight coefficient vector to obtain a weighted first difference; Any weight coefficient in the first weight coefficient vector is determined according to the importance levels of different phases of the three-phase bus and environmental characteristics.

[0030] In this embodiment, in the power system, different phases of the three-phase bus have different importance in load distribution, power transmission, etc. For example, some key equipment may be mainly connected to a certain phase, so that the operating state of the phase has a greater impact on the stability and reliability of the entire system, then the weight coefficient of the phase should be increased accordingly. Or in a specific power system layout, a certain phase is significantly affected by the environment and needs to be given a higher weight.

[0031] From the above, it can be concluded that the analysis of the difference between the first phase of the three-phase fundamental voltage and the second phase of the corresponding three-phase fundamental leakage current (the first difference) is not comprehensive and accurate enough for evaluating the operating status of the arrester. Due to the different roles and positions of the three-phase busbars in the entire power system, their importance to the evaluation of the operating status of the arrester is also different. In addition, different environmental characteristics will also affect the operation of the arrester on each phase. Therefore, through weighted processing, the three-phase situation can be more reasonably considered comprehensively, the influence of important factors can be highlighted, and the actual operating status of the arrester can be more accurately reflected.

[0032] In one embodiment of the present disclosure, the environmental characteristics include ambient temperature, relative humidity, and number of lightning strikes; Online monitoring methods also include: Calculate any weight coefficient according to the first formula, which is:

[0033] in, represents the i-th weight coefficient in the first weight coefficient vector, corresponding to the i-th phase in the three-phase bus; i=A, B or C; Represents the quantitative value of the importance level of the i-th phase bus; A function representing ambient temperature, used to convert the actual value of ambient temperature into a corresponding quantitative value; A function representing relative humidity, used to convert the actual value of relative humidity into a corresponding quantitative value; A function representing the number of lightning strikes; , , and They represent the weight distribution coefficients of importance level, ambient temperature, relative humidity and number of lightning strikes respectively. .

[0034] In this embodiment, It can be determined by expert scoring, statistical analysis of historical fault data, etc. For example, if the importance level is divided into 5 levels, corresponding to 1 to 5 points, the higher the importance, the greater the score.

[0035] The function representing the ambient temperature can be expressed in the form of a piecewise function:

[0036] in, and They are the lower and upper limits of the set ambient temperature. When the temperature is lower than the lower limit, the quantization value is 0; when the temperature is higher than the upper limit, the quantization value is 1; the value between the two is taken in linear proportion.

[0037] The function representing relative humidity can be expressed in the following piecewise function form:

[0038] in, and They are the lower and upper limits of the set ambient temperature. When the temperature is lower than the lower limit, the quantization value is 0; when the temperature is higher than the upper limit, the quantization value is 1; the value between the two is taken in linear proportion.

[0039] The function representing the number of lightning strikes can set the quantization rule according to the number of lightning strikes. The reference formula is as follows:

[0040] in, The upper limit of the number of lightning strikes is set. When the number of lightning strikes is 0, the quantization value is 0. When the number of lightning strikes reaches or exceeds the upper limit, the quantization value is 1. The value between the two is taken proportionally.

[0041] , , and They represent the weight distribution coefficients of importance level, ambient temperature, relative humidity and number of lightning strikes respectively. These coefficients can be determined by methods such as the analytic hierarchy process and the entropy weight method to reflect the relative importance of different factors in the weight calculation.

[0042] It can be concluded from the above that this embodiment uses the first formula to calculate the weight coefficient of each phase bus by comprehensively considering environmental characteristics such as ambient temperature, relative humidity and number of lightning strikes, as well as the importance level of the bus, thereby achieving comprehensive and objective online monitoring of the bus operation status. This method improves the accuracy and reliability of monitoring, provides a strong guarantee for the safe and stable operation of the power system, and at the same time, the parameters are determined by expert scoring, historical data analysis and other methods, which enhances the practicality of the method.

[0043] In one embodiment of the present disclosure, determining the operating state of the arrester based on the subordinate relationship between the weighted first difference and the preset numerical range includes: If the weighted first difference belongs to the preset value interval, it is determined that the operating state of the lightning arrester is normal; If the weighted first difference does not belong to the preset numerical interval, determining the phase angle difference increment, the target resistive fundamental current amplitude and the target third harmonic amplitude based on the multiple second phases; The operating state of the arrester is determined based on the phase angle difference increment, the target resistive fundamental current amplitude and the target third harmonic amplitude.

[0044] Determining an inter-phase angle difference increment based on a plurality of second phases includes: Subtracting the initial phase angles of two adjacent fundamental leakage currents to obtain an initial phase angle difference, and obtaining the phase angle difference of two adjacent fundamental leakage currents according to a plurality of second phases; there are three initial phase angle differences and three phase angle differences; The interphase angle difference is subtracted from the corresponding initial interphase angle difference to obtain the interphase angle difference increment and the interphase angle difference increment.

[0045] In this embodiment, the preset numerical interval is a preset numerical range, and this range can be determined according to the parameter range of the arrester under normal operating conditions. For example, the preset numerical interval can be [10°, 15°]. If the weighted first difference belongs to the preset numerical interval, it means that the operating parameters of the arrester are within the normal range, so it can be determined that the operating state of the arrester is normal.

[0046] The phase angle difference refers to the phase difference between adjacent fundamental leakage currents, and the increment is the change relative to the initial phase angle difference.

[0047] In the initial stage, the initial phase angles of the two adjacent fundamental leakage currents are subtracted to obtain three initial phase angle differences. The initial stage can be the time period when the arrester is operating normally. According to multiple second phases, the phase angle differences of the two adjacent fundamental leakage currents in the current state are obtained, and these phase differences reflect the phase relationship of the leakage current during the current operation of the arrester. The current phase angle difference is subtracted from the corresponding initial phase angle difference to obtain the phase angle difference increment, which can reflect the degree of change of the phase relationship of the phase leakage current relative to the initial state.

[0048] When the arrester ages, the performance of its internal zinc oxide valve plate and other components will decline. The aging process will change the resistance and capacitance components of each phase, which will affect the current phase. However, this change is relatively slow and uniform. Normally, the phase angle difference increment of the three phases will gradually and synchronously increase. For example, due to the change of nonlinear characteristics caused by the aging of the valve plate, the leakage current phase of the three phases will slowly change in a similar direction, so that the phase angle difference increment will gradually increase within a relatively small range, and the change trend between the three phases is relatively consistent.

[0049] When the arrester is damp, the degree of dampness can vary among the three phases. The uneven distribution of moisture inside the arrester will cause inconsistent changes in the electrical parameters of the three phases. The dielectric constant and conductivity of the damp phase will change significantly, causing the leakage current characteristics of the phase to change. For example, a phase that is severely damp will have a large current phase shift. Unlike aging, dampness will cause a significant mutation in the increment of the phase angle difference between one or two phases.

[0050] Therefore, when the arrester is aged, the change of the target phase angle difference increment is relatively slow and uniform, and the increment difference between the three phases is small; when it is damp, the phase angle difference increment may change greatly and unevenly due to the uneven degree of dampness, and one or two phases may have obvious mutations. By monitoring the change speed of the target phase angle difference increment and the difference between the three phases, it can assist in judging whether the arrester is aged or damp.

[0051] The target resistive fundamental current amplitude is the current amplitude of the resistive part of the fundamental current during the operation of the arrester. It is very important for evaluating the performance changes of the arrester (such as aging, moisture, etc.). The target third harmonic amplitude is the amplitude of the third harmonic part of the arrester operating current. When the arrester fails (such as nonlinear characteristics change), the third harmonic amplitude will change.

[0052] For example, when the arrester ages, the performance of the zinc oxide valve plate inside it will gradually decline, and the nonlinear characteristics of the zinc oxide valve plate will change, causing the resistive fundamental current amplitude to gradually increase and the third harmonic amplitude to gradually increase. However, the rate of increase in the third harmonic amplitude caused by aging is slower than the growth of the target resistive fundamental current amplitude, because it is mainly based on the gradual degradation of the valve plate performance.

[0053] When the arrester is damp, the moisture inside it will change the electric field distribution, causing the leakage current to increase, and the target resistive fundamental current amplitude will increase. This is because moisture provides an additional conductive channel, making it easier for the current to pass through the arrester, and the main increase is the resistive current part. When damp, the third harmonic amplitude will also increase. This is because the local electric field distortion and increased dielectric loss caused by dampness increase the nonlinearity of the current, thereby increasing the third harmonic content. Compared with aging, dampness will cause the third harmonic amplitude to increase significantly in a shorter period of time.

[0054] It can be concluded from the above that this embodiment can determine whether the current abnormality of the lightning arrester is caused by equipment aging or moisture by judging the changes in the target resistive fundamental current amplitude and the target third harmonic amplitude growth amount.

[0055] In one embodiment of the present disclosure, the method for online monitoring of a wave recording type lightning arrester further includes: The phase-to-phase angle difference increment is input into a preset electric field distortion model to obtain the phase-to-phase electric field distortion coefficient; the phase-to-phase electric field distortion coefficient is used to determine the degree of distortion of the electric field inside the arrester.

[0056] In this embodiment, the target phase-to-phase angle difference increment is used as an input parameter and input into the preset electric field distortion model to calculate the phase-to-phase electric field distortion coefficient. This coefficient can more intuitively reflect the degree of distortion of the electric field inside the lightning arrester, and when the phase-to-phase electric field distortion coefficient exceeds the set safety threshold, an electric field distortion warning signal is issued.

[0057] The electric field distortion model can be constructed by the following formula:

[0058] in, represents the phase-to-phase electric field distortion coefficient, Indicates the target phase angle difference increment, is the functional relationship obtained by fitting the simulated data.

[0059] For example, the electric field distortion model is

[0060] a, b, and c are model parameters determined based on simulation data. Generally speaking, the larger the electric field distortion coefficient, the more uneven the electric field distribution inside the arrester, the greater the impact on the insulation performance, and the higher the risk of failure. Electric field distortion accelerates the aging of components inside the arrester. For zinc oxide resistors in the arrester, uneven electric fields can lead to uneven current distribution inside the resistors. In areas of high electric field strength, the current density is large and more heat is generated. This local overheating phenomenon can cause changes in the performance of zinc oxide resistors, such as changes in resistance value and decreases in nonlinear coefficients.

[0061] From the above, it can be concluded that by judging the degree of electric field distortion, the accelerated aging of the lightning arrester can be discovered in time, and maintenance or replacement measures can be taken in advance.

[0062] In one embodiment of the present disclosure, the online monitoring method of the wave recording type lightning arrester further includes: When the arrester is in normal operation, the preset monitoring period is extended to the first monitoring period; When the arrester is operating abnormally, the preset monitoring period is shortened to a second monitoring period. If the number of arrester failures is greater than the first value during the second monitoring period, the monitoring period is shortened by the first step based on the second monitoring period.

[0063] In this embodiment, when the arrester is in normal operation, extending the preset monitoring period to the first monitoring period is a reasonable resource optimization strategy. During normal operation, frequent monitoring consumes a large amount of system resources. By appropriately extending the monitoring period, these resources can be allocated to other key equipment or system links that require real-time monitoring, thereby improving the utilization efficiency of the monitoring resources of the entire power system.

[0064] When the arrester is in an abnormal operating state, the preset monitoring period is shortened to the second monitoring period in order to timely capture the development of the arrester fault. If the number of arrester faults is greater than the first value in the second monitoring period, this indicates that the arrester fault is more serious and occurs frequently. At this time, the monitoring period can be gradually shortened with the first step length.

[0065] Determine the first step length based on the type and specification characteristics of the arrester. Arrester of different types (such as zinc oxide arresters, silicon carbide arresters, etc.) and different specifications (such as rated voltage, nominal discharge current, etc.) have different fault development speeds and characteristics. For example, zinc oxide arresters develop relatively quickly when they are aged or damp. For such arresters, when determining the first step length, it can be set based on the statistical data of their normal aging rate and fault development. If the statistical data show that under a certain fault mode, the performance indicators of zinc oxide arresters (such as leakage current, resistive current, etc.) may change significantly within a few days, then the first step length can be set in hours, such as 1-2 hours, so that these changes can be captured in time.

[0066] From the above, it can be concluded that, on the one hand, this embodiment dynamically adjusts the monitoring period, extends the period when the lightning arrester is normal, reasonably allocates resources, avoids waste of resources, and improves the overall utilization efficiency of the monitoring resources of the power system; on the other hand, when the lightning arrester is abnormal, the period is shortened, especially when faults occur frequently, the first step length is further shortened, and the fault development can be captured in time. The step length determined based on the characteristics of the lightning arrester can accurately track the fault changes, effectively improving the timeliness and accuracy of fault monitoring, and ensuring the safe and stable operation of the power system.

[0067] Corresponding to the on-line monitoring method of the wave recording type lightning arrester in the above embodiment, Figure 2 This is a structural block diagram of a wave recording type arrester online monitoring device provided by an embodiment of the present disclosure. For ease of explanation, only the parts related to the embodiment of the present disclosure are shown. Figure 2 The wave recording type arrester online monitoring device 20 includes: a first calculation module 21, a second calculation module 22 and a state determination module 23.

[0068] The first calculation module 21 is used to calculate the three-phase basic voltage data of the three-phase bus of the recording type lightning arrester based on the fast Fourier transform algorithm to obtain the fundamental voltage amplitude and the first phase; The second calculation module 22 is used to calculate the resistive fundamental current amplitude and the second phase based on the fundamental voltage amplitude and the three-phase fundamental leakage current data of the three-phase busbar of the recording type lightning arrester; the first phase and the second phase have three each; The state determination module 23 is used to calculate the first difference between each first phase and the corresponding second phase, process the first difference to obtain a weighted first difference, and determine the operating state of the lightning arrester based on the subordinate relationship between the weighted first difference and a preset numerical range.

[0069] In one embodiment of the present disclosure, the state determination module 23 is specifically used to: Performing weighted processing on the first difference according to the first weight coefficient vector to obtain a weighted first difference; Any weight coefficient in the first weight coefficient vector is determined according to the importance levels of different phases of the three-phase bus and environmental characteristics.

[0070] In one embodiment of the present disclosure, the environmental characteristics include ambient temperature, relative humidity, and number of lightning strikes; The state determination module 23 is further specifically used for: Calculate any weight coefficient according to the first formula, which is:

[0071] in, represents the i-th weight coefficient in the first weight coefficient vector, corresponding to the i-th phase in the three-phase bus; i=A, B or C; Represents the quantitative value of the importance level of the i-th phase bus; A function representing ambient temperature, used to convert the actual value of ambient temperature into a corresponding quantitative value; A function representing relative humidity, used to convert the actual value of relative humidity into a corresponding quantitative value; A function representing the number of lightning strikes; , , and They represent the weight distribution coefficients of importance level, ambient temperature, relative humidity and number of lightning strikes respectively. .

[0072] In one embodiment of the present disclosure, the state determination module 23 is specifically used to: If the weighted first difference belongs to the preset value interval, it is determined that the operating state of the lightning arrester is normal; If the weighted first difference does not belong to the preset numerical interval, determining the phase angle difference increment, the target resistive fundamental current amplitude and the target third harmonic amplitude based on the multiple second phases; The operating state of the arrester is determined based on the phase angle difference increment, the target resistive fundamental current amplitude and the target third harmonic amplitude.

[0073] In one embodiment of the present disclosure, the state determination module 23 is specifically used to: Subtracting the initial phase angles of two adjacent fundamental leakage currents to obtain an initial phase angle difference, and obtaining the phase angle difference of two adjacent fundamental leakage currents according to a plurality of second phases; there are three initial phase angle differences and three phase angle differences; The interphase angle difference is subtracted from the corresponding initial interphase angle difference to obtain the interphase angle difference increment, and the interphase angle difference increment with the largest value is selected as the interphase angle difference increment.

[0074] In one embodiment of the present disclosure, the state determination module 23 is further configured to: The phase-to-phase angle difference increment is input into a preset electric field distortion model to obtain the phase-to-phase electric field distortion coefficient; the phase-to-phase electric field distortion coefficient is used to determine the degree of distortion of the electric field inside the arrester.

[0075] In one embodiment of the present disclosure, the state determination module 23 is further configured to: When the arrester is in normal operation, the preset monitoring period is extended to the first monitoring period; When the arrester is operating abnormally, the preset monitoring period is shortened to a second monitoring period. If the number of arrester failures is greater than the first value during the second monitoring period, the monitoring period is shortened by the first step based on the second monitoring period.

[0076] See also Figure 3 , Figure 3 A schematic block diagram of an electronic device provided by an embodiment of the present disclosure. Figure 3 The electronic device 300 in the embodiment shown may include: one or more processors 301, one or more input devices 302, one or more output devices 303 and one or more memories 304. The processors 301, input devices 302, output devices 303 and memories 304 communicate with each other via a communication bus 305. The memory 304 is used to store computer programs, which include program instructions. The processor 301 is used to execute the program instructions stored in the memory 304. The processor 301 is configured to call the program instructions to execute the functions of each module / unit in the above-mentioned device embodiments, such as Figure 2 The functions of modules 21 to 23 are shown.

[0077] It should be understood that in the embodiment of the present disclosure, the processor 301 may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0078] The input device 302 may include a touch panel, a fingerprint collection sensor (for collecting the user's fingerprint information and fingerprint direction information), a microphone, etc., and the output device 303 may include a display (LCD, etc.), a speaker, etc.

[0079] The memory 304 may include a read-only memory and a random access memory, and provide instructions and data to the processor 301. A portion of the memory 304 may also include a non-volatile random access memory. For example, the memory 304 may also store information about the device type.

[0080] In a specific implementation, the processor 301, input device 302, and output device 303 described in the embodiments of the present disclosure can execute the implementation methods described in the first and second embodiments of the online monitoring method of the wave recording type lightning arrester provided in the embodiments of the present disclosure, and can also execute the implementation methods of the electronic device described in the embodiments of the present disclosure, which will not be repeated here.

[0081] In another embodiment of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by the processor, all or part of the processes in the above-mentioned embodiment method are implemented, and the computer program can also be completed by instructing the relevant hardware through the computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, the steps of each of the above-mentioned method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0082] The computer-readable storage medium may be an internal storage unit of the electronic device of any of the aforementioned embodiments, such as a hard disk or memory of the electronic device. The computer-readable storage medium may also be an external storage device of the electronic device, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (SecureDigital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device. Furthermore, the computer-readable storage medium may also include both an internal storage unit of the electronic device and an external storage device. The computer-readable storage medium is used to store computer programs and other programs and data required by the electronic device. The computer-readable storage medium may also be used to temporarily store data that has been output or is to be output.

[0083] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this disclosure.

[0084] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the electronic devices and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0085] In the several embodiments provided in the present application, it should be understood that the disclosed electronic devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces or units, or it can be an electrical, mechanical or other form of connection.

[0086] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present disclosure.

[0087] In addition, each functional unit in each embodiment of the present disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0088] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present disclosure, and these modifications or replacements should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for online monitoring of a wave recording type lightning arrester, characterized in that: include: The three-phase basic voltage data of the three-phase busbar of the recording type lightning arrester is calculated based on the fast Fourier transform algorithm to obtain the fundamental voltage amplitude and the first phase; Based on the fundamental voltage amplitude and the three-phase fundamental leakage current data of the three-phase busbar of the recording type lightning arrester, the resistive fundamental current amplitude and the second phase are calculated; the first phase and the second phase have three each; A first difference between each first phase and the corresponding second phase is calculated, the first difference is processed to obtain a weighted first difference, and the operating state of the arrester is determined based on a subordinate relationship between the weighted first difference and a preset numerical range.

2. The method for online monitoring of a wave recording type lightning arrester according to claim 1, characterized in that: The step of processing the first difference to obtain a weighted first difference includes: Performing weighted processing on the first difference according to the first weight coefficient vector to obtain a weighted first difference; Any weight coefficient in the first weight coefficient vector is determined according to the importance levels of different phases of the three-phase bus and environmental characteristics.

3. The on-line monitoring method for wave recording type lightning arrester according to claim 2, characterized in that: Environmental characteristics include ambient temperature, relative humidity, and number of lightning strikes; The online monitoring method further comprises: Any weight coefficient is calculated according to the first formula, wherein the first formula is: in, represents the i-th weight coefficient in the first weight coefficient vector, corresponding to the i-th phase in the three-phase bus; i=A, B or C; Represents the quantitative value of the importance level of the i-th phase bus; A function representing ambient temperature, used to convert the actual value of ambient temperature into a corresponding quantitative value; A function representing relative humidity, used to convert the actual value of relative humidity into a corresponding quantitative value; A function representing the number of lightning strikes; , , and They represent the weight distribution coefficients of importance level, ambient temperature, relative humidity and number of lightning strikes respectively. .

4. The method for online monitoring of a wave recording type lightning arrester according to claim 1, characterized in that: The determining the operating state of the arrester based on the subordinate relationship between the weighted first difference and the preset numerical range includes: If the weighted first difference belongs to the preset value interval, it is determined that the operating state of the lightning arrester is normal; If the weighted first difference does not belong to the preset numerical interval, determining the phase angle difference increment, the target resistive fundamental current amplitude and the target third harmonic amplitude based on the multiple second phases; The operating state of the arrester is determined based on the phase angle difference increment, the target resistive fundamental current amplitude and the target third harmonic amplitude.

5. The on-line monitoring method for wave recording type lightning arrester according to claim 4, characterized in that: The step of determining the phase angle difference increment based on the plurality of second phases comprises: Subtracting initial phase angles of two adjacent fundamental leakage currents to obtain initial phase angle differences, and obtaining phase angle differences of two adjacent fundamental leakage currents according to multiple second phases; the initial phase angle differences are three, and the phase angle differences are three; The interphase angle difference is subtracted from the corresponding initial interphase angle difference to obtain the interphase angle difference increment and the interphase angle difference increment.

6. The method for online monitoring of a wave recording type lightning arrester according to claim 5, characterized in that: Also includes: Inputting the phase angle difference increment into the preset electric field distortion model to obtain the phase electric field distortion coefficient; The phase-to-phase electric field distortion coefficient is used to determine the degree of distortion of the electric field inside the arrester.

7. The method for online monitoring of a wave recording type lightning arrester according to claim 1, characterized in that: Also includes: When the arrester is in normal operation, the preset monitoring period is extended to the first monitoring period; When the arrester is operating abnormally, the preset monitoring period is shortened to a second monitoring period. If the number of arrester failures is greater than the first value during the second monitoring period, the monitoring period is shortened by the first step based on the second monitoring period.

8. A wave recording type arrester online monitoring device, characterized in that: include: A first calculation module is used to calculate the three-phase basic voltage data of the three-phase bus of the recording type lightning arrester based on a fast Fourier transform algorithm to obtain a fundamental voltage amplitude and a first phase; A second calculation module is used to calculate the resistive fundamental current amplitude and the second phase based on the fundamental voltage amplitude and the three-phase fundamental leakage current data of the three-phase busbar of the recording type lightning arrester; the first phase and the second phase have three each; The state determination module is used to calculate the first difference between each first phase and the corresponding second phase, process the first difference to obtain a weighted first difference, and determine the operating state of the lightning arrester based on the subordinate relationship between the weighted first difference and a preset numerical range.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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