A method, system and terminal for fault monitoring of a power transmission line

Abstract

The application relates to a fault monitoring method, system and terminal for a power transmission line, and belongs to the technical field of power transmission line monitoring. The fault monitoring method comprises the following steps: acquiring a voltage value of an electric field monitoring point arranged on an insulator shed in a power transmission line; obtaining a corresponding synthetic field intensity according to the voltage value of the electric field monitoring point; judging whether the maximum synthetic field intensity in all synthetic field intensities is greater than a set field intensity threshold value; if yes, marking the electric field monitoring point corresponding to the maximum synthetic field intensity as a flashover path initial point; predicting a flashover path according to a path equation; judging whether the flashover path continuously passes through three sheds; if yes, triggering an alarm. The application has the beneficial effect of discovering potential flashover fault hidden dangers in time, so as to reduce the fault risk of the power transmission line under extreme environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power transmission line monitoring, and in particular to a fault monitoring method, system and terminal for a power transmission line. BACKGROUND

[0002] In modern society, the stability of power supply is of great importance, and the safe operation of power transmission lines, as the key infrastructure for power transmission, directly affects the normal operation of society. In particular, in extreme environments, such as facing a freeze-thaw alternating temperature range of-20℃ to 5℃, and complex pollution conditions of coastal salt fog (NaCl deposition amount ≥0.2mg / cm 2 ) and industrial dust (CaSO4accounting for >40%), the operation of power transmission lines faces great challenges. In such environments, the equipment of power transmission lines, such as insulators, is easily damaged, which in turn causes flashover and other faults, seriously affecting the reliability of power supply.

[0003] Currently, there are various ways to monitor the faults of power transmission lines. Some traditional methods rely on manual regular inspection, and operation and maintenance personnel need to conduct on-site inspection in harsh extreme environments to check whether the appearance of power transmission line equipment is damaged, whether the insulator surface is polluted, and the like. In addition, some areas use ultraviolet imagers to detect partial discharge phenomena, and capture ultraviolet light generated by partial discharge to determine whether there are potential fault risks. These methods can to some extent find some obvious faults, but their effectiveness is greatly limited in extreme environments and complex pollution conditions.

[0004] The manual inspection method is inefficient and is greatly affected by extreme environments. In freeze-thaw alternating and complex pollution conditions, the work difficulty and risk of operation and maintenance personnel are greatly increased, and it is difficult to achieve real-time and comprehensive monitoring. When the ultraviolet imager faces the nonlinear conductive layer formed after the pollution is absorbed, its undetected rate is >60% due to the hidden starting point of partial discharge, and it cannot accurately and timely find potential flashover fault risks, resulting in an increased risk of faults of power transmission lines in extreme environments. SUMMARY

[0005] In order to timely find potential flashover fault risks and reduce the risk of faults of power transmission lines in extreme environments, the present application provides a fault monitoring method, system and terminal for a power transmission line.

[0006] In a first aspect, the present application provides a fault monitoring method for a power transmission line, which adopts the following technical solution:

[0007] A fault monitoring method for a power transmission line, comprising:

[0008] obtaining a voltage value of an electric field monitoring point arranged on an insulator shed in the power transmission line;

[0009] According to the voltage value of the electric field monitoring point, a corresponding synthetic field strength is obtained;

[0010] It is judged whether the maximum synthetic field strength in all synthetic field strengths is greater than a set field strength threshold value;

[0011] If yes, the electric field monitoring point corresponding to the maximum synthetic field strength is marked as a flashover path initial point;

[0012] According to the path equation, a flashover path is predicted;

[0013] It is judged whether the flashover path continuously passes through three umbrella skirts;

[0014] If yes, an alarm is triggered.

[0015] By adopting the above technical solution, under the complex pollution conditions of coastal salt spray and industrial dust, after the pollutants absorb moisture, a nonlinear conductive layer will be formed on the surface of the insulator. This conductive layer will change the electric field distribution on the surface of the insulator and increase the risk of flashover failure. The monitoring method does not rely on the detection of ultraviolet generated by partial discharge, but analyzes the voltage value of the electric field monitoring point and the synthetic field strength to judge the failure, which can find the potential flashover path from the overall change of the electric field. Even if the partial discharge starting point is difficult to find by naked eye or ultraviolet imager, the flashover path initial point can also be accurately found through abnormal changes in the electric field, and the flashover path can be predicted, which greatly improves the discovery ability of hidden partial discharge failure. In addition, by determining the flashover path initial point and predicting the flashover path, the operation and maintenance personnel can quickly and accurately find the location where the failure may occur, shorten the fault troubleshooting time, reduce the number of unnecessary comprehensive inspections, and reduce the operation and maintenance cost.

[0016] Optionally, the step of predicting the flashover path according to the path equation comprises:

[0017] The ion mobility of an ion monitoring point arranged on the steel leg of the insulator in the power transmission line is obtained, and the ion includes sodium ion and calcium ion; according to the electric field gradient of the flashover path initial point and the ion mobility, an ion migration speed is obtained;

[0018] According to the ion migration speed, the electric field gradient and the path equation, a flashover position is predicted;

[0019] According to the flashover position, a flashover path is predicted;

[0020] Path equation Δt is a time step, is a flashover position, k is a slope adjustment, is an electric field gradient, is an ion migration speed, μ1 is the ion mobility of sodium ions, and μ2 is the ion mobility of calcium ions.

[0021] By adopting the technical scheme, under the pollution conditions of coastal salt mist and industrial dust, sodium ions and calcium ions are common and exist in large quantities. Since ions migrate in an electric field, the mobility of the ions affects the development process of flashover, and therefore, by obtaining the ion mobility and combining the electric field gradient of the initial point of the flashover path to obtain the ion migration speed, the physical process when flashover occurs can be more comprehensively and accurately reflected, thereby improving the accuracy of flashover path prediction.

[0022] Optionally, the step after triggering the alarm comprises:

[0023] determining whether the alarm duration reaches a duration threshold;

[0024] if yes, performing a local heating action on the insulator;

[0025] during the heating process, obtaining a leakage current of the insulator;

[0026] determining whether the leakage current decreases and whether a decrease value exceeds a decrease threshold within a set time;

[0027] if yes, marking as processed.

[0028] By adopting the technical scheme, under the pollution conditions of coastal salt mist and industrial dust, sodium ions and calcium ions are common and exist in large quantities. Since ions migrate in an electric field, the mobility of the ions affects the development process of flashover, and therefore, by obtaining the ion mobility and combining the electric field gradient of the initial point of the flashover path to obtain the ion migration speed, the physical process when flashover occurs can be more comprehensively and accurately reflected, thereby improving the accuracy of flashover path prediction.

[0029] Optionally, the step after determining whether the leakage current decreases and whether a decrease value exceeds a decrease threshold within a set time further comprises:

[0030] if no, calling a UAV to perform ultraviolet imaging review on the insulator and obtaining an actual flashover path;

[0031] determining whether a deviation value between the actual flashover path and the predicted flashover path exceeds a deviation threshold;

[0032] if yes, adjusting a k value of the path equation;

[0033] knew k is the adjusted k value, k old k is the unadjusted k value, Δs is the deviation value, s max s is the maximum value of the deviation allowed.

[0034] By adopting the above technical solution, the unmanned aerial vehicle ultraviolet imaging can detect the insulator from multiple angles in the air, capture the ultraviolet light generated by partial discharge, and obtain the actual flashover path, so as to more accurately judge the fault condition of the power transmission line. By judging whether the deviation value between the actual flashover path and the predicted flashover path exceeds the deviation threshold, the accuracy of the prediction model can be further verified. The predicted flashover path is derived based on ion mobility, electric field gradient and other factors, but in complex extreme environments, the actual situation may be different. By comparing the deviation values of the two, the difference between the prediction result and the actual situation can be found in time, providing a basis for subsequent adjustment of the path equation, making the fault diagnosis more accurate. When the deviation value between the actual flashover path and the predicted flashover path exceeds the deviation threshold, the k value of the path equation is adjusted, which can make the path equation more consistent with the actual situation.

[0035] Optionally, before predicting the flashover path, it comprises:

[0036] Obtaining the ambient temperature;

[0037] According to the ambient temperature and the set resistivity correction formula, the actual resistivity is calculated;

[0038] Judging whether the actual resistivity is less than the set resistivity;

[0039] If yes, adjust the k value of the path equation;

[0040] The resistivity correction formula is ρ0 is the reference resistivity at 20 degrees Celsius, B is the characteristic constant of mixed pollutants, T is the ambient temperature, and ρ sj s is the actual resistivity; ρ sd s is the set resistivity.

[0041] By adopting the above technical solution, in the coastal salt spray and industrial dust pollution environment, the nonlinear conductive layer formed by the moisture absorption of pollutants will jointly act with temperature changes to further change the electrical characteristics of the insulator. By obtaining the ambient temperature and calculating the actual resistivity according to the set resistivity correction formula, the electrical conductivity of the insulator in the current environment can be more accurately reflected. Different resistivity will cause changes in electric field distribution and ion migration, and then affect the flashover path. By adjusting the k value, the path equation can better fit the actual situation, improve the accuracy of flashover path prediction, and provide more reliable basis for subsequent fault monitoring and early warning.

[0042] Optionally, the calculating the actual resistivity comprises:

[0043] According to the ion mobility, an ion mobility ratio is calculated;

[0044] According to the ion mobility ratio, a mobility standard deviation is calculated;

[0045] It is judged whether the mobility standard deviation is greater than a standard deviation threshold value;

[0046] If yes, a B value in the resistivity correction formula is adjusted;

[0047] The mobility standard deviation N is an effective measurement window, R i is an ion mobility ratio of the ith measurement, is an average value of the ion mobility ratio within the effective measurement window; the ion mobility ratio μ Na+ is an ion mobility of sodium ions, μ Ca+ is an ion mobility of calcium ions.

[0048] By using the above technical solution, the ion mobility ratio and the mobility standard deviation further reflect the distribution of the ion mobility characteristics. Different ion mobility characteristics will cause the change of the conductive performance of the mixed contaminants, thereby affecting the resistivity of the insulator. By calculating the ion mobility ratio and the mobility standard deviation according to the ion mobility, the influence of the ion mobility on the resistivity can be more comprehensively and carefully considered, and a more reliable basis for accurately calculating the actual resistivity is provided. When the mobility standard deviation is greater than the standard deviation threshold value, it indicates that the distribution of the ion mobility characteristics is relatively dispersed, and the conductive performance of the mixed contaminants may have changed greatly. The mixed contaminant characteristic constant reflects the comprehensive characteristics of the mixed contaminants, and adjusting it can make the calculation of the resistivity more in line with the actual situation, reduce the calculation error of the resistivity caused by the change of the mixed contaminant characteristics, and improve the accuracy of the resistivity calculation.

[0049] Optionally, the step before calculating the mobility standard deviation comprises:

[0050] An offset value of the ion mobility ratio and a set ratio threshold value is obtained;

[0051] According to the offset value, the effective measurement window is adjusted.

[0052] By adopting the technical scheme, various interference factors exist in the extreme environment, which may cause abnormal fluctuations in the ion mobility ratio. If a fixed measurement window is used, the data of the abnormal fluctuations may be included in the calculation, thereby affecting the accuracy of the mobility standard deviation. The effective measurement window is adjusted according to the offset value, so that the measurement window can better adapt to the actual situation of the current ion migration, avoid the data deviation caused by the fixed measurement window, and improve the accuracy of the ion mobility related data measurement.

[0053] In a second aspect, the application provides a fault monitoring system for a power transmission line, which adopts the following technical scheme:

[0054] A fault monitoring system for a power transmission line comprises:

[0055] A data acquisition module is configured to acquire voltage values of electric field monitoring points arranged on insulator sheds in the power transmission line, and obtain corresponding synthetic field strengths according to the voltage values of the electric field monitoring points.

[0056] A judgment module is configured to judge whether a maximum synthetic field strength among all the synthetic field strengths is greater than a set field strength threshold.

[0057] A marking module is configured to mark the electric field monitoring point corresponding to the maximum synthetic field strength as an initial point of a flashover path when the judgment module judges yes.

[0058] A flashover path prediction module is configured to predict a flashover path according to a path equation.

[0059] The judgment module is further configured to judge whether the flashover path continuously passes through 3 sheds.

[0060] An alarm module is configured to trigger an alarm when the judgment module judges yes.

[0061] In a third aspect, the application provides a terminal, which adopts the following technical scheme:

[0062] A terminal comprises:

[0063] A memory is configured to store a fault monitoring program for a power transmission line.

[0064] A processor is configured to execute the program stored on the memory, so as to implement the steps of the above-mentioned fault monitoring method for a power transmission line.

[0065] In summary, the application has at least the following beneficial effects:

[0066] Under the complex pollution conditions of coastal salt spray and industrial dust, pollutants will form a nonlinear conductive layer on the surface of the insulator after absorbing moisture. This conductive layer will change the electric field distribution on the surface of the insulator and increase the risk of flashover failure. The monitoring method does not rely on the detection of ultraviolet generated by partial discharge, but analyzes the voltage value and synthetic field strength of the electric field monitoring point to judge the failure, which can find the potential flashover path from the overall change of the electric field. Even if the starting point of the partial discharge is difficult to find by the naked eye or ultraviolet imager, the initial point of the flashover path can also be accurately found through the abnormal change of the electric field, and the flashover path can be predicted, which greatly improves the ability to find hidden partial discharge failure. In addition, by determining the initial point of the flashover path and predicting the flashover path, the operation and maintenance personnel can quickly and accurately find the location where the failure may occur, shorten the troubleshooting time, reduce the number of unnecessary comprehensive inspections, and reduce the operation and maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0067] Figure 1 is the first flowchart of the method embodiment of the present application;

[0068] Figure 2 is the second flowchart of the method embodiment of the present application;

[0069] Figure 3 is the third flowchart of the method embodiment of the present application;

[0070] Figure 4 is the fourth flowchart of the method embodiment of the present application;

[0071] Figure 5 is the fifth flowchart of the method embodiment of the present application;

[0072] Figure 6 is the sixth flowchart of the method embodiment of the present application. DETAILED DESCRIPTION

[0073] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the accompanying drawings of the embodiments of the present application to further describe the embodiments of the present application in detail. Figure 1 -attached Figure 6 , the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0074] The first embodiment of the present application discloses a fault monitoring method for a power transmission line. Referring to Figure 1 , as an implementation of the fault monitoring method, the fault monitoring method can include S110-S180:

[0075] S110, acquire voltage values of electric field monitoring points arranged on the insulator shed of the power transmission line;

[0076] S120, obtain corresponding synthetic field strengths according to the voltage values of the electric field monitoring points;

[0077] S130, determine whether the maximum synthetic field strength among all the synthetic field strengths is greater than a set field strength threshold value;

[0078] S140, if yes, mark the electric field monitoring point corresponding to the maximum synthetic field strength as a flashover path initial point;

[0079] S150, predict a flashover path according to a path equation;

[0080] S160, determine whether the flashover path continuously passes through 3 sheds;

[0081] S170, if yes, trigger an alarm;

[0082] S180, if no, record path parameters and continuously monitor.

[0083] Specifically, distributed electric field probes are arranged at the edges of the insulator sheds of the power transmission line, each of which represents an electric field monitoring point, so that voltage monitoring is performed through the distributed electric field probes. An electric field model of the insulator is established by using a finite element analysis software (such as COMSOL Multiphysics), and then the acquired voltage values of the electric field monitoring points are input as boundary conditions into the model. The software numerically solves the electric field around the insulator based on the Maxwell equations, and calculates the electric field strength vector of each monitoring point. Then, according to the vector synthesis method, the electric field strength vectors of the monitoring points are synthesized to obtain the corresponding synthetic field strengths. For example, E hc is the synthetic field strength, E x is the tangential component, and E y is the normal component.

[0084] Referring to Figure 2 , for S150, the specific steps can include S210-S240:

[0085] S210, acquire ion mobility of ion monitoring points arranged on the steel legs of the insulator of the power transmission line, the ions including sodium ions and calcium ions;

[0086] S220, obtain ion migration speed according to the electric field gradient of the flashover path initial point and the ion mobility;

[0087] S230, predict a flashover position according to the ion migration speed, the electric field gradient, and the path equation;

[0088] S240, according to the flashover position, the flashover path is predicted.

[0089] Specifically, the path equation Δt is the time step, is the flashover position, k adjusts the slope, is the electric field gradient, is the ion migration speed, μ1 is the ion mobility of sodium ions, and μ2 is the ion mobility of calcium ions.

[0090] An ion mobility sensor is installed in the steel foot of the insulator, one ion mobility sensor corresponds to one ion monitoring point, and is used to monitor the mobility of sodium ions and calcium ions.

[0091] In addition, a temperature sensor and a humidity sensor are also installed at the insulator to measure the ambient temperature and relative humidity.

[0092] It should be noted that after the sensing data is collected, the sensing data is normalized. The formula for normalization is x g is the normalized sensing data, x d is the sensing data before normalization, τ is the mean of the sensing data, and σ' is the standard deviation of the sensing data.

[0093] After obtaining the initial flashover position (flashover path initial point), the fourth-order Runge-Kutta iteration formula is used to obtain the intermediate flashover position and the final flashover position under one time step, and the flashover path under one time step is determined according to the initial flashover position, the intermediate flashover position and the final flashover position.

[0094] The fourth-order Runge-Kutta iteration formula is:

[0095]

[0096] For example, the initial flashover position is Δt=0.1ms, the path equation

[0097] Calculate k1: known t0=0,

[0098] k1=0.1·[0.324·(25.3, 9.6, 0)+0.676·(106.3, 7.7, 0)]=(8.17, 3.15, 0) μm;

[0099] k2, k3, k4, The calculation process of k2, k3 and k4 is omitted, and finally At a time step, the predicted flashover path is k1, k2, k3, k4, The path is composed of

[0100] Since the distance between adjacent sheds is 10 cm, it is known that the predicted flashover path continuously crosses 3 sheds, thus triggering an alarm.

[0101] In addition, with reference to Figure 3 Before predicting the flashover position, S310-S350 need to be performed:

[0102] S310, obtaining the ambient temperature;

[0103] S320, calculating the actual resistivity according to the ambient temperature and the set resistivity correction formula;

[0104] S330, judging whether the actual resistivity is less than the set resistivity;

[0105] S340, if yes, adjusting the k value of the path equation;

[0106] S350, if no, maintaining the original k value of the path equation.

[0107] Specifically, the resistivity correction formula is ρ0 is the reference resistivity at 20 degrees Celsius, B is the characteristic constant of mixed pollutants, T is the ambient temperature, and ρ sj is the actual resistivity. ρ sd is the set resistivity.

[0108] In addition, if the ambient temperature is less than 0 degrees Celsius and the relative humidity is greater than 90%, the resistivity can be updated every 5 minutes; otherwise, the resistivity can be updated every hour.

[0109] With reference to Figure 4 Before S320, steps S410-S450 need to be performed:

[0110] S410, calculating the ion mobility ratio according to the ion mobility;

[0111] S420, calculating the mobility standard deviation according to the ion mobility ratio;

[0112] S430, judging whether the mobility standard deviation is greater than the standard deviation threshold;

[0113] S440, if yes, adjusting the B value in the resistivity correction formula;

[0114] S450, if no, maintaining the original B value in the resistivity correction formula.

[0115] Specifically, the ion mobility ratio μ Na+ is the ion mobility of sodium ion, μ Ca+ is the ion mobility of calcium ion.

[0116] mobility standard deviation N is the effective measurement window, R i is the ion mobility ratio of the i-th measurement, is the average value of the ion mobility ratio within the effective measurement window.

[0117] In addition, after calculating the ion mobility ratio and before calculating the mobility standard deviation, the offset value of the ion mobility ratio from the set ratio threshold value can be obtained; when the offset value is less than or equal to the offset value threshold value, the effective measurement window N can be shortened, and when the offset value is greater than the offset value threshold value, the original effective measurement window N is maintained.

[0118] It should be noted that when R is greater than 5 and σ is greater than 0.1, the frequency of the electric field scan can be increased, for example, 1KHz; when R is less than or equal to 5, the basic scan frequency is maintained, for example, 10Hz.

[0119] In addition, if the ambient temperature drops and the drop value is greater than the drop threshold value, the effective measurement window N is directly shortened; and the B value in the resistivity correction formula is directly increased.

[0120] Referring to Figure 5 and Figure 6 , the steps after triggering the alarm include S510-S590:

[0121] S510, determining whether the alarm duration reaches the duration threshold;

[0122] S520, if so, performing a local heating action on the insulator;

[0123] S530, obtaining the leakage current of the insulator during the heating process;

[0124] S540, determining whether the leakage current decreases and the decrease value exceeds the decrease threshold value within a set time;

[0125] S550, if so, marking as processed;

[0126] S560, if not, calling a UAV to perform ultraviolet imaging review on the insulator and obtaining the actual flashover path;

[0127] S570, determining whether the deviation value of the actual flashover path and the predicted flashover path exceeds the deviation threshold value;

[0128] S580, if so, adjusting the k value of the path equation;

[0129] S590, if no, maintaining the k value of the path equation unchanged, recording the path parameters.

[0130] Specifically, the specific steps of performing the local heating action can include:

[0131] According to the thickness and area of the pollution layer, the basic power P0 of the heating device is calculated;

[0132] Obtain wind speed data of ambient wind speed;

[0133] According to the wind speed data, the basic power is corrected to obtain the adjusted total power of the heating device.

[0134] Basic power A is the area of the pollution layer, d is the thickness of the pollution layer, ρ'' is the density of the pollution layer, c p is the specific heat capacity of the pollution layer, ΔT is the target temperature rise, L f is the latent heat of phase change, t is the target time length, λ p is the thermal conductivity of the pollution layer, for example, when the pollution type is salt fog ice layer, λ p = 2.2, when the pollution type is industrial dust, λ p = 0.5.

[0135] Adjusted total power P z = P0·(1+0.15v f ), v f is the wind speed data obtained by data normalization processing of the ambient wind speed data measured by the wind speed sensor.

[0136] The leakage current of the insulator can be indirectly measured by thermal imaging technology or ultrasonic technology.

[0137] When the leakage current does not decrease or the decrease value does not exceed the decrease threshold value within a predetermined time, the unmanned aerial vehicle can be called to perform ultraviolet imaging review on the insulator to obtain the actual flashover path; the actual flashover path is compared with the predicted flashover path, and if the deviation value of the two exceeds the deviation threshold value, the k value of the path equation is adjusted.

[0138] k new is the adjusted k value, k old is the unadjusted k value, Δs is the deviation value, s max is the maximum value of the deviation allowed.

[0139] Based on the above method embodiments, the second embodiment of the present application discloses a fault monitoring system for a power transmission line. The fault monitoring system for the power transmission line can implement any of the above fault monitoring methods for the power transmission line, and the specific working processes of each module in the fault monitoring system for the power transmission line can refer to the corresponding processes in the above fault monitoring method embodiments for the power transmission line.

[0140] For ease of understanding, the following is an example: a fault monitoring system for a power transmission line, comprising:

[0141] a data acquisition module configured to acquire voltage values of electric field monitoring points arranged on insulator sheds in the power transmission line, and obtain corresponding synthetic field strengths according to the voltage values of the electric field monitoring points;

[0142] a judgment module configured to judge whether a maximum synthetic field strength among all the synthetic field strengths is greater than a set field strength threshold;

[0143] a marking module configured to mark the electric field monitoring point corresponding to the maximum synthetic field strength as an initial point of a flashover path when the judgment module judges yes;

[0144] a flashover path prediction module configured to predict a flashover path according to a path equation;

[0145] the judgment module is further configured to judge whether the flashover path continuously passes through 3 sheds;

[0146] an alarm module configured to trigger an alarm when the judgment module judges yes.

[0147] The third embodiment of the present application provides a terminal, which can include a memory and a processor as an implementation manner of the terminal, wherein,

[0148] the memory is configured to store a fault monitoring program for a power transmission line;

[0149] the processor is configured to execute the program stored on the memory to implement the steps of the above fault monitoring method for the power transmission line.

[0150] The memory can be in communication connection with the processor through a communication bus, and the communication bus can be an address bus, a data bus, a control bus, etc.

[0151] In addition, the memory can include a random access memory (RAM) and can also include a non-volatile memory (NVM), such as at least one disk memory.

[0152] The processor can be a general purpose processor, including a central processing unit (CPU), a network processing unit (NP), etc.; can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, etc.

[0153] The above are only preferred embodiments of the present application, not intended to limit the protection scope of the present application, any feature disclosed in the specification (including the abstract and the drawings) can be replaced by other equivalent or similar features, unless specifically described. That is, each feature is only an example of a series of equivalent or similar features, unless specifically described.

Claims

1. A fault monitoring method for transmission lines, characterized in that, include: Obtain the voltage values ​​of electric field monitoring points deployed on the insulator skirts of transmission lines; The corresponding composite field strength is obtained based on the voltage value at the electric field monitoring point; Determine whether the maximum composite field strength among all composite field strengths is greater than the set field strength threshold; If so, the electric field monitoring point corresponding to the maximum combined field strength is marked as the flashover path initial point; Predict flashover paths based on path equations; Determine whether the flashover path passes through 3 umbrella skirts consecutively; If so, an alarm will be triggered; The step of predicting the flashover path based on the path equation includes: The ion mobility of ion monitoring points deployed on the steel feet of insulators in transmission lines is obtained, including sodium ions and calcium ions; The ion migration velocity is obtained based on the electric field gradient at the initial point of the flashover path and the ion mobility. Predict the flashover location based on the ion migration velocity, the electric field gradient, and the path equation; Predict the flashover path based on the flashover location; Path equation For time step, To determine the flashover location, k adjusts the slope. For the electric field gradient, For ion migration rate, The ion mobility is that of sodium ions. The ion mobility of calcium ions. The electric field intensity is the tangential component. This represents the normal component of the electric field intensity.

2. The fault monitoring method for transmission lines according to claim 1, characterized in that, The steps following the triggering of the alarm include: Determine whether the alarm duration has reached the duration threshold; If so, then perform local heating on the insulator; During the heating process, the leakage current of the insulator is obtained; Determine whether the leakage current has decreased, and whether the decrease value exceeds the decrease threshold within a set time. If so, the mark has been processed.

3. The fault monitoring method for transmission lines according to claim 2, characterized in that, The step after determining whether the leakage current has decreased and whether the decrease value exceeds the decrease threshold within a set time period further includes: If not, then use a drone to perform ultraviolet imaging verification of the insulator and obtain the actual flashover path; Determine whether the deviation between the actual flashover path and the predicted flashover path exceeds a deviation threshold; If so, then adjust the value of k in the path equation; The adjusted value of k. The value of k before adjustment. This is the deviation value. This represents the maximum allowable deviation.

4. The fault monitoring method for transmission lines according to claim 1, characterized in that, Before predicting the flashover path, the following is included: Obtain the ambient temperature; The actual resistivity is calculated based on the ambient temperature and the set resistivity correction formula. Determine whether the actual resistivity is less than the set resistivity; If so, adjust the value of k in the path equation; The resistivity correction formula is as follows: The base resistivity is 20 degrees Celsius, B is the characteristic constant of the mixed pollutants, and T is the ambient temperature. This is the actual resistivity; To set the resistivity.

5. A fault monitoring method for transmission lines according to claim 4, characterized in that, The calculation of actual resistivity includes the following: Calculate the ion mobility ratio based on the stated ion mobility; Calculate the standard deviation of the mobility based on the stated ion mobility ratio; Determine whether the standard deviation of the mobility is greater than the standard deviation threshold; If so, adjust the value of B in the resistivity correction formula; The migration rate standard deviation N is the effective measurement window. The ratio of ion mobilities measured in the i-th measurement. To effectively measure the average ion mobility ratio within the measurement window; the ion mobility ratio The ion mobility is that of sodium ions. The ion mobility is denoted as α.

6. A fault monitoring method for transmission lines according to claim 5, characterized in that, The steps preceding the calculation of the standard deviation of the mobility rate include: Obtain the offset value between the ion mobility ratio and the set ratio threshold; Adjust the effective measurement window based on the offset value.

7. A fault monitoring system for transmission lines, characterized in that, Performing the fault monitoring method for transmission lines as described in any one of claims 1-6, comprising: The data acquisition module is used to acquire the voltage values ​​of electric field monitoring points deployed on the insulator skirts of the transmission line; and to obtain the corresponding composite field strength based on the voltage values ​​of the electric field monitoring points. The judgment module is used to determine whether the maximum composite field strength among all composite field strengths is greater than the set field strength threshold. The marking module is used to mark the electric field monitoring point corresponding to the maximum combined field strength as the initial point of the flashover path when the judgment module determines that it is true; The flashover path prediction module is used to predict flashover paths based on path equations. The judgment module is also used to determine whether the flashover path passes through 3 umbrella skirts consecutively; An alarm module is used to trigger an alarm when the judgment module determines that the judgment is correct.

8. A terminal, characterized in that, include: The memory stores fault monitoring programs for power transmission lines; A processor is configured to execute a program stored in the memory to implement the steps of the fault monitoring method for transmission lines as described in any one of claims 1-6.

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