A system and method for measuring grounding resistance of towers in a grounding ring network

Abstract

The invention belongs to the technical field of electric power engineering, and discloses a system and method for measuring the grounding resistance of a pole tower in a grounding ring network, comprising a data acquisition module, which is used to acquire current values ​​and voltage values ​​of grounding lines in different switching states under different environments; a first data processing module, which is used to calculate the grounding resistance values ​​in different grounding lines according to the current values ​​and voltage values ​​of grounding lines in different switching states under different environments; preprocessing the grounding resistance values ​​in different grounding lines to obtain grounding resistance data sets in different grounding lines; a resistance change prediction module, which is used to train and acquire a line pole tower grounding resistance prediction model according to the grounding resistance data sets in different grounding lines, and predict the change trend of the line pole tower grounding resistance through the line pole tower grounding resistance prediction model; and accurate monitoring of the grounding resistance is achieved, which is helpful to discover potential problems early and reduce the risk of failure.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power engineering, and more particularly to a system and method for measuring the grounding resistance of a tower in a grounding ring network. Background Art

[0002] The patent application publication number CN115144657A discloses a method for measuring the grounding resistance of a transmission tower. The method includes: short-circuiting the grounding down conductors corresponding to the pole feet of the measured tower, retaining the connection between the grounding down conductor and one of the pole feet, and disconnecting the connection between the grounding down conductor and the remaining pole feet to build a test model; measuring the down conductor current value and the current value of each grounding body under the first working condition and the second working condition, and calculating the branch current of the remote multi-level grounding body; calculating the grounding resistance of the measured tower according to the down conductor current value and the current value of each grounding body under the first working condition and the second working condition, the branch current of the remote multi-level grounding body, and the preset parallel equivalent resistance of the remote multi-level grounding body. The present invention builds a test model, measures the current value of each loop of the equivalent circuit under the first working condition and the second working condition, and calculates the grounding resistance of the measured tower in combination with the preset parallel equivalent resistance of the remote multi-level grounding body; improves the accuracy of grounding resistance measurement.

[0003] The existing systems and methods for measuring the grounding resistance of towers in grounding ring networks have the following main problems:

[0004] The priority of the grounding line cannot be adjusted dynamically according to actual needs and environment, resulting in unreasonable test sequence and extended total test time; the grounding line cannot be switched quickly, resulting in uneven resource allocation or waste, especially when multiple lines need to be tested at the same time; the lack of dynamic priority adjustment based on the importance of the line may cause the key line to be tested later, affecting the entire test goal; failure to consider resource constraints may result in the number of lines switched at the same time exceeding the equipment capacity, causing contactor overload or switching failure;

[0005] Failure to consider actual environmental parameters may cause the switching logic to be out of touch with the actual situation, reducing test accuracy; lack of importance formula and matrix representation, unclear line switching logic, which may cause key line switching to be delayed or low-priority lines to occupy resources; failure to define the target optimization function, resulting in insufficient optimization of the total switching time of the grounding line, leading to slow system response; cumulative switching delays affect real-time performance in a dynamic test environment;

[0006] Failure to combine historical test data with current environmental parameters and relying solely on real-time data will ignore historical trends and environmental impacts, making it difficult to fully grasp the laws of line performance changes; lack of a dynamic resource allocation mechanism makes it impossible to reasonably allocate resources when high-priority lines and low-priority lines need to be switched at the same time; failure to introduce resource limit constraints may result in the number of lines switched simultaneously exceeding the maximum parallel switching capacity of the normally closed contactor, causing resource conflicts or equipment overloads; failure to reasonably allocate resources while minimizing switching time may result in insufficient resources or excessive resource use.

[0007] In view of this, the present invention proposes a system and method for measuring the grounding resistance of a tower in a grounding ring network to solve the above-mentioned problem. Summary of the invention

[0008] In order to overcome the above-mentioned defects of the prior art and to achieve the above-mentioned purpose, the present invention provides the following technical solution: a system for measuring the grounding resistance of a tower in a grounding ring network, comprising:

[0009] A data acquisition module, used to obtain current values ​​and voltage values ​​of the grounding line in different switching states under different environments;

[0010] The first data processing module is used to calculate the grounding resistance values ​​in different grounding lines according to the current values ​​and voltage values ​​of the grounding lines in different switching states under different environments; pre-process the grounding resistance values ​​in different grounding lines to obtain grounding resistance data sets in different grounding lines;

[0011] The resistance change prediction module is used to train and obtain a line tower grounding resistance prediction model based on the grounding resistance data sets in different grounding lines, and predict the change trend of the line tower grounding resistance through the line tower grounding resistance prediction model;

[0012] The second data processing module is used to obtain the predicted resistance value of the grounding resistance according to the change trend of the grounding resistance of the line tower;

[0013] A resistance judgment module is used to compare the predicted resistance value of the grounding resistance with the preset resistance threshold of the grounding resistance to judge whether the grounding resistance of the line tower is in a dangerous range;

[0014] Danger alarm module: if the grounding resistance of the line tower is in a dangerous range, an audible and visual alarm will be issued through the resistance measurement intelligent terminal, and the specific location of the tower will be displayed; each module is connected by wire and / or wireless means.

[0015] Furthermore, the method for obtaining the current value and voltage value of the grounding line in different switching states under different environments includes:

[0016] S21, switch the grounding circuit through the normally closed contactor, and collect the current and voltage values ​​of the grounding circuit in different switching states under different environments; The switching state of each ground line is determined by the global control signal and the ground line priority;

[0017] The switching state of each ground line is expressed as: ;in, For the The switching status of the grounding line, , When it is 1, it means the ground line is switched. When it is 0, it means that the ground line is not switched; is the global control signal, , When it is 1, it means that the ground line is allowed to switch. When it is 0, it means that the ground line is not allowed to switch; For the Ground line priority, When it is 1, it means that the ground line switching is allowed. When it is 0, it means that the ground line switching is not allowed. ; is the index of the switching state of the ground line, ; is the timing step of the global control signal;

[0018] When the global control signal is 1 and the ground line priority When 1, the ground line Switch;

[0019] S22, Ground line priority The distribution of grounding lines is dynamically adjusted according to their importance; The importance of the grounding line is , then Ground line priority Defined as: ;in, is a preset threshold value of importance of the grounding line;

[0020] The importance of the grounding line is calculated as follows: ; For grounding line Comprehensive values ​​of current environmental parameters; For grounding line frequency of occurrence in historical tests; A weight coefficient to balance the impact of the comprehensive value of current environmental parameters on the importance of the grounding line; A weight coefficient for balancing the influence of the frequency of occurrence of the grounding line in historical tests on the importance of the grounding line;

[0021] The current environmental parameters include soil temperature, soil moisture, soil conductivity and ground electrode corrosion degree; ground line The comprehensive value of the current environmental parameters is expressed as: ;in, For grounding line The soil temperature of the area; For grounding line Soil moisture in the area; For grounding line Soil conductivity in the area; For grounding line The degree of corrosion of the grounding electrode in the area; For grounding line Soil temperature weighting factor for the region; For grounding line Soil moisture weighting factor for the region; For grounding line The soil conductivity weighting factor for the area; For grounding line Weight factor of ground electrode corrosion degree in the area;

[0022] Grounding Circuit The frequency of occurrence in historical tests is expressed as: ;in, For grounding line The number of tests participated in in the historical test; is the total number of historical tests;

[0023] S23, using a matrix to represent the switching status and priority of all grounding lines; the switching status matrix of all grounding lines is represented as: ;in, For the The switching status of the grounding lines; is the number of grounding lines; the priority matrix of all grounding lines is expressed as: ;

[0024] S24. Define the total switching time of the grounding line as: ;in, is the total switching time of the grounding line; It is the start-up delay time of the grounding circuit; is the actual switching time of the grounding line; is the maximization operator, which means finding the maximum value of the sum of the start-up delay time and the switching operation time among all grounding lines;

[0025] S25, define the target optimization function to minimize the total switching time of the grounding line; switch all grounding lines by switching the state matrix A and the priority matrix Through joint control, the switching state of the grounding line is dynamically adjusted, and the current and voltage values ​​of each grounding line under different environments are collected.

[0026] Furthermore, the method of defining the target optimization function to minimize the total switching time of the ground line includes:

[0027] Define a target optimization function to adjust the global control signal and the priority matrix , so that the total switching time of the grounding line is the shortest; the objective optimization function is: ;in, is the shortest total switching time for the grounding line; To adjust the global control signal and the priority matrix , so that the total switching time of the grounding line is minimized;

[0028] Define the constraints of the target optimization function, which include resource limitation constraints and priority limitation constraints; the resource limitation constraint is that in the same time period, the total number of grounding lines allowed to be switched is less than or equal to the maximum number of parallel switching supported by the normally closed contactor;

[0029] The resource limit constraint expression is: ;in, is the total number of grounding lines being switched among all grounding lines in the same time period; The maximum number of parallel switching supported by the normally closed contactor; The first one in the global control signal The switching status of the grounding lines; The first one in the global control signal The index of the time at which the switching state of the grounding line is located;

[0030] The precedence restriction constraint expression is: ; Indicates that the ground lines in the priority matrix must be ground lines allowed by the global control signal.

[0031] Furthermore, the method for calculating the grounding resistance values ​​in different grounding circuits according to the current values ​​and voltage values ​​of the grounding circuits in different switching states under different environments includes:

[0032] Preset total acquisition The current and voltage values ​​under different environments, Total Article 2, definition The grounding line is The current value under this environment is , No. The grounding line is The voltage value under this environment is ; According to Ohm's law, we can calculate The grounding line is The resistance value under this environment is .

[0033] Furthermore, the method of preprocessing the grounding resistance values ​​in different grounding lines to obtain the grounding resistance data sets in different grounding lines includes:

[0034] The OPTICS algorithm is used to identify and eliminate outliers in the grounding resistance values ​​in different grounding lines. Wavelet transform denoising and feature extraction are performed on the grounding resistance values ​​in different grounding lines after eliminating outliers to obtain the grounding resistance data set in different grounding lines. The grounding resistance data set in different grounding lines is normalized by standard deviation and converted into a standard normal distribution to obtain the normalized grounding resistance data set in different grounding lines.

[0035] Furthermore, the training method of the line tower grounding resistance prediction model includes:

[0036] The data set is divided into a training set, a test set and a validation set, and a line tower grounding resistance prediction model is constructed; the sample set is a subset of the data set, and each sample set includes a grounding resistance data set in different historical grounding lines and a corresponding change trend of the line tower grounding resistance; the input data of the model is a grounding resistance data set in different historical grounding lines; the output label is a change trend of the line tower grounding resistance; the line tower grounding resistance prediction model is a random forest regression model;

[0037] Initialize the line tower grounding resistance prediction model and set the number and depth hyperparameters of the tree. Use the training set to train the line tower grounding resistance prediction model, use the test set data to evaluate the performance of the model, and use the determination coefficient to evaluate the difference between the calculated prediction result and the true label.

[0038] According to the performance feedback of the validation set, the number and depth hyperparameters of the trees are adjusted to tune the model. The model is retrained using the adjusted hyperparameters. The training is stopped when the performance index of the validation set reaches the preset performance index threshold or the model performance no longer improves, and the final trained line tower grounding resistance prediction model is obtained. The trained line tower grounding resistance prediction model is used to predict the grounding resistance data sets in the current different grounding lines to predict the changing trend of the line tower grounding resistance.

[0039] Furthermore, the method for obtaining the predicted resistance value of the grounding resistance according to the change trend of the line tower grounding resistance includes:

[0040] The change trend of the line tower grounding resistance is preset to be , the predicted resistance value of the grounding resistance is calculated by the grounding resistance prediction formula; the grounding resistance prediction formula is: ;in, is the predicted resistance value of the grounding resistor; It is the ground resistance value obtained at the current moment.

[0041] Furthermore, the method of comparing the predicted resistance value of the grounding resistance with the preset resistance threshold of the grounding resistance to determine whether the grounding resistance of the line tower is in a dangerous range includes:

[0042] If the predicted resistance value of the grounding resistance is greater than or equal to the preset resistance threshold of the grounding resistance, it is determined that the grounding resistance of the line tower is in a dangerous range;

[0043] If the predicted resistance value of the grounding resistance is less than the preset resistance value of the grounding resistance, it is determined that the grounding resistance of the line tower is not in a dangerous range.

[0044] Furthermore, if the grounding resistance of the line tower is in a dangerous range, the method of using the resistance measurement intelligent terminal to issue an audible and visual alarm and display the specific location of the tower includes:

[0045] The resistance measurement intelligent terminal automatically triggers the sound and light alarm; the sound and light alarm includes an audible alarm and a flashing warning light; the audible alarm emits a continuous high-frequency alarm sound through a buzzer; the flashing warning light emits an obvious warning signal through an LED flashing light; the GPS positioning technology is used to obtain and display in real time the specific location of the tower where the grounding resistance abnormality occurs.

[0046] A method for measuring the grounding resistance of a tower in a grounding ring network, comprising:

[0047] S1. Switch the grounding circuit through a normally closed contactor, and collect the current and voltage values ​​of the grounding circuit in different switching states under different environments;

[0048] S2. Based on the current values ​​and voltage values ​​of the grounding lines in different switching states under different environments, the grounding resistance values ​​in different grounding lines are calculated; the grounding resistance values ​​in different grounding lines are preprocessed to obtain grounding resistance data sets in different grounding lines;

[0049] S3, training a line tower grounding resistance prediction model based on grounding resistance data sets in different grounding lines, and predicting the change trend of the line tower grounding resistance through the line tower grounding resistance prediction model;

[0050] S4. According to the change trend of the grounding resistance of the line tower, the predicted resistance value of the grounding resistance is obtained;

[0051] S5, comparing the predicted resistance value of the grounding resistance with the predicted resistance threshold of the grounding resistance to determine whether the grounding resistance of the line tower is in a dangerous range;

[0052] S6. If the grounding resistance of the line tower is within the dangerous range, the resistance measurement intelligent terminal will give an audible and visual alarm and display the specific location of the tower.

[0053] The technical effects and advantages of the system and method for measuring the grounding resistance of a tower in a grounding ring network of the present invention are as follows:

[0054] The present invention optimizes the switching logic according to actual environmental parameters and historical test data of the line by dynamically adjusting the priority and switching state of the grounding line to ensure that it can adapt to different scenarios and needs; uses global control signals and priority mechanisms to quickly switch the grounding line, reducing the time and resources required for testing, especially when multiple grounding lines are involved at the same time; dynamically adjusts the priority based on the importance of the grounding line, can give priority to testing key lines, reasonably allocate resources, and improve test results;

[0055] Comprehensively consider environmental parameters (such as soil temperature, humidity, conductivity, etc.) and the degree of ground electrode corrosion to ensure that the collected current and voltage data are comprehensive and accurate in different environments; use importance formulas and matrix representation to systematize and standardize complex line switching and priority control systems to facilitate subsequent data analysis and decision-making; by defining the target optimization function, the total switching time of the ground line is minimized, reducing the system response time problem caused by switching delays and improving the real-time performance of the test;

[0056] The combination of historical test data and current environmental parameters not only facilitates real-time monitoring, but also enables predictions of future grounding line performance and reliability. Resource limitation constraints are introduced to ensure that switching operations within the same time period do not exceed the maximum parallel switching capacity of the normally closed contactor to avoid resource overload and conflict. Switching resources are reasonably allocated while minimizing switching time to avoid performance degradation or system failure due to insufficient or excessive use of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic diagram of the structure of a measuring system for the grounding resistance of a tower in a grounding ring network of the present invention;

[0058] Figure 2 The present invention is a flow chart of a method for measuring the grounding resistance of a tower in a grounding ring network. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] Example 1

[0061] See also Figure 1 As shown, the present embodiment provides a system for measuring the grounding resistance of a tower in a grounding ring network, comprising:

[0062] A data acquisition module, used to obtain current values ​​and voltage values ​​of the grounding line in different switching states under different environments;

[0063] The first data processing module is used to calculate the grounding resistance values ​​in different grounding lines according to the current values ​​and voltage values ​​of the grounding lines in different switching states under different environments; pre-process the grounding resistance values ​​in different grounding lines to obtain grounding resistance data sets in different grounding lines;

[0064] The resistance change prediction module is used to train and obtain a line tower grounding resistance prediction model based on the grounding resistance data sets in different grounding lines, and predict the change trend of the line tower grounding resistance through the line tower grounding resistance prediction model;

[0065] The second data processing module is used to obtain the predicted resistance value of the grounding resistance according to the change trend of the grounding resistance of the line tower;

[0066] A resistance judgment module is used to compare the predicted resistance value of the grounding resistance with the preset resistance threshold of the grounding resistance to judge whether the grounding resistance of the line tower is in a dangerous range;

[0067] Danger alarm module: if the grounding resistance of the line tower is in a dangerous range, an audible and visual alarm will be issued through the resistance measurement intelligent terminal, and the specific location of the tower will be displayed; each module is connected by wire and / or wireless means.

[0068] Methods for obtaining current values ​​and voltage values ​​of grounding lines in different switching states under different environments include:

[0069] S21, switch the grounding circuit through the normally closed contactor, and collect the current and voltage values ​​of the grounding circuit in different switching states under different environments; The switching state of each ground line is determined by the global control signal and the ground line priority;

[0070] The switching state of each ground line is expressed as: ;in, For the The switching status of the grounding line, , When it is 1, it means the ground line is switched. When it is 0, it means that the ground line is not switched; is the global control signal, , When it is 1, it means that the ground line is allowed to switch. When it is 0, it means that the ground line is not allowed to switch; For the Ground line priority, When it is 1, it means that the ground line switching is allowed. When it is 0, it means that the ground line switching is not allowed. ; is the index of the switching state of the ground line, ; is the timing step of the global control signal;

[0071] When the global control signal is 1 and the ground line priority When 1, the ground line Switch;

[0072] S22, Ground line priority The distribution of grounding lines is dynamically adjusted according to their importance; The importance of the grounding line is , then Ground line priority Defined as: Among them, is a preset threshold value of importance of the grounding line;

[0073] The importance of the grounding line is calculated as follows: ; For grounding line Comprehensive values ​​of current environmental parameters; For grounding line frequency of occurrence in historical tests; A weight coefficient to balance the impact of the comprehensive value of current environmental parameters on the importance of the grounding line; A weight coefficient for balancing the influence of the frequency of occurrence of the grounding line in historical tests on the importance of the grounding line;

[0074] Current environmental parameters include soil temperature, soil moisture, soil conductivity and ground electrode corrosion; grounding line The comprehensive value of the current environmental parameters is expressed as: Among them, For grounding line The soil temperature of the area; For grounding line Soil moisture in the area; For grounding line Soil conductivity in the area; For grounding line The degree of corrosion of the grounding electrode in the area; For grounding line Soil temperature weighting factor for the region; For grounding line Soil moisture weighting factor for the region; For grounding line The soil conductivity weighting factor for the area; For grounding line Weight factor of ground electrode corrosion degree in the area;

[0075] Grounding Circuit The frequency of occurrence in historical tests is expressed as: ;in, For grounding line The number of tests participated in in the historical test; is the total number of historical tests;

[0076] S23, using a matrix to represent the switching status and priority of all grounding lines; the switching status matrix of all grounding lines is represented as: ;in, For the The switching status of the grounding lines; is the number of grounding lines; the priority matrix of all grounding lines is expressed as: ;

[0077] S24. Define the total switching time of the grounding line as: ;in, is the total switching time of the grounding circuit, i.e., the maximum value of the sum of the start-up delay time and the switching operation time in all grounding circuits; The start-up delay time of the grounding line is the time from when the switching command is issued to when the line is ready for switching; is the actual switching time of the grounding line, that is, the time required from the start of switching to the completion of switching; is the maximization operator, which means finding the maximum value of the sum of the start-up delay time and the switching operation time among all grounding lines;

[0078] S25, define the target optimization function to minimize the total switching time of the grounding line; switch all grounding lines by switching the state matrix A and the priority matrix Through joint control, the switching state of the grounding line is dynamically adjusted, and the current and voltage values ​​of each grounding line under different environments are collected.

[0079] For example, suppose there are three grounding lines, namely grounding line 1, grounding line 2, and grounding line 3; the current environmental parameters are:

[0080] Soil temperature: grounding line 1 is 25°C, grounding line 2 is 30°C, and grounding line 3 is 35°C;

[0081] Soil moisture: 20% for grounding line 1, 25% for grounding line 2, and 15% for grounding line 3;

[0082] Soil conductivity: grounding line 1 is 1.5S / m, grounding line 2 is 1.2S / m, and grounding line 3 is 1.8S / m;

[0083] Ground electrode corrosion degree: ground line 1 is 5%, ground line 2 is 8%, and ground line 3 is 10%;

[0084] Environmental parameter weighting factors: ground line Soil temperature weighting factor for the region 0.3, ground line Soil moisture weighting factor for the region 0.2; grounding circuit Soil conductivity weighting factor for the area 0.4; grounding circuit Weight factor of ground electrode corrosion degree in the area is 0.1;

[0085] Calculate the comprehensive value of current environmental parameters:

[0086] (ground line 1) = 0.3 × 25 + 0.2 × 20 + 0.4 × 1.5 + 0.1 × 5 = 10.95;

[0087] (ground line 2) = 0.3 × 30 + 0.2 × 25 + 0.4 × 1.2 + 0.1 × 8 = 12.08;

[0088] (ground line 3) = 0.3 × 35 + 0.2 × 15 + 0.4 × 1.8 + 0.1 × 10 = 13.52;

[0089] Assume that the number of times grounding lines 1, 2, and 3 participated in the historical test is 10, 20, and 15, and the total number of historical tests is 50; (Ground Line 1) = ; (Ground Line 2) = ; (Ground Line 3) = ;

[0090] Calculate the importance: Assume that the weight coefficient of the comprehensive value of the current environmental parameters affects the importance of the grounding line =0.7, the weight coefficient of the frequency of occurrence of the balanced grounding line in the historical test affecting the importance of the grounding line The preset importance threshold of the grounding line is 0.3. is 10;

[0091] Then the importance of grounding line 1 is 0.7×10.95+0.3×0.2=7.665; the importance of grounding line 2 is 0.7×12.08+0.3×0.4=8.496; the importance of grounding line 3 is 0.7×13.52+0.3×0.3=9.464; if , the priority is 1, otherwise it is 0. Here, grounding lines 1, 2, and 3 do not exceed the preset importance threshold of grounding lines, so the priority matrix is ; Assume that the global control signal , then the switch state matrix ;

[0092] Assume that the start-up delay time of the grounding line and the actual switching time of the grounding line are:

[0093] Ground circuit 1: =2s, =3s; Grounding line 2: =1.5s, =2.5s; Grounding line 3: =3s, =2s; then the total switching time of the grounding line is: =5s.

[0094] Methods for defining the objective optimization function to minimize the total switching time of the ground line include:

[0095] Define a target optimization function to adjust the global control signal and the priority matrix , so that the total switching time of the grounding line is the shortest; the objective optimization function is: ;in, is the shortest total switching time for the grounding line; To adjust the global control signal and the priority matrix , so that the total switching time of the grounding line is minimized;

[0096] Define the constraints of the target optimization function, which include resource limitation constraints and priority limitation constraints; the resource limitation constraint is that in the same time period, the total number of grounding lines allowed to be switched is less than or equal to the maximum number of parallel switching supported by the normally closed contactor;

[0097] The resource limit constraint expression is: ;in, is the total number of grounding lines being switched among all grounding lines in the same time period; The maximum number of parallel switching supported by the normally closed contactor; The first one in the global control signal The switching status of the grounding lines; The first one in the global control signal The index of the time at which the switching state of the grounding line is located;

[0098] The precedence restriction constraint expression is: ; indicates that the ground line in the priority matrix must be a ground line allowed by the global control signal. In other words, its priority is meaningful only when the global control signal allows the line to switch; if =0, that is, the line cannot be switched at this time step, then the priority of the line Invalid, and switching operation cannot be performed; the high priority line in the priority matrix can only be Switching can only be performed when switching is allowed, otherwise it cannot be switched even if the priority is high.

[0099] Methods for calculating the grounding resistance values ​​in different grounding lines according to the current values ​​and voltage values ​​of the grounding lines in different switching states under different environments include:

[0100] Preset total acquisition The current and voltage values ​​under different environments, Total Article 2, definition The grounding line is The current value under this environment is , No. The grounding line is The voltage value under this environment is ; According to Ohm's law, we can calculate The grounding line is The resistance value under this environment is .

[0101] For example, suppose there are 3 grounding lines and 2 kinds of environment data. The current of grounding line 1 in environment 1 and environment 2 are respectively and ; The voltages of ground line 1 in environment 1 and environment 2 are respectively and ; According to Ohm's law, the resistance of grounding line 1 in environment 1 is Resistance value of grounding line 1 in environment 2 .

[0102] The method of preprocessing the grounding resistance values ​​in different grounding lines to obtain the grounding resistance data sets in different grounding lines includes:

[0103] The OPTICS algorithm is used to identify and eliminate outliers in the grounding resistance values ​​in different grounding lines. Wavelet transform denoising and feature extraction are performed on the grounding resistance values ​​in different grounding lines after eliminating outliers to obtain the grounding resistance data set in different grounding lines. The grounding resistance data set in different grounding lines is normalized by standard deviation and converted into a standard normal distribution to obtain the normalized grounding resistance data set in different grounding lines.

[0104] The training method of the line tower grounding resistance prediction model includes:

[0105] The data set is divided into training set, test set and validation set to build a line tower grounding resistance prediction model; the sample set is a subset of the data set, each sample set includes the grounding resistance data set in different historical grounding lines and the corresponding line tower grounding resistance change trend; the input data of the model is the grounding resistance data set in different historical grounding lines; the output label is the change trend of the line tower grounding resistance; the line tower grounding resistance prediction model is a random forest regression model;

[0106] Initialize the line tower grounding resistance prediction model and set the number and depth hyperparameters of the tree. Use the training set to train the line tower grounding resistance prediction model, use the test set data to evaluate the performance of the model, and use the determination coefficient to evaluate the difference between the calculated prediction result and the true label.

[0107] The coefficient of determination is ;in, The sum of squares of the differences between the changing trend of the line tower grounding resistance predicted by the model and the changing trend of the actual line tower grounding resistance; It is the sum of squares of the difference between the actual change trend of the line tower grounding resistance and the average value of the change trend of the grounding resistance of all line towers; For the The changing trend of the grounding resistance of each line tower; The model predicts The changing trend of the grounding resistance of each line tower; is the average value of the change trend of the grounding resistance of all line towers; is the sample size;

[0108] According to the performance feedback of the validation set, the number and depth hyperparameters of the trees are adjusted to tune the model. The model is retrained using the adjusted hyperparameters. The training is stopped when the performance index of the validation set reaches the preset performance index threshold or the model performance no longer improves, and the final trained line tower grounding resistance prediction model is obtained. The trained line tower grounding resistance prediction model is used to predict the grounding resistance data sets in the current different grounding lines to predict the changing trend of the line tower grounding resistance.

[0109] According to the changing trend of the grounding resistance of the line tower, the method of obtaining the predicted resistance value of the grounding resistance includes:

[0110] The change trend of the line tower grounding resistance is preset to be , the predicted resistance value of the grounding resistance is calculated by the grounding resistance prediction formula; the grounding resistance prediction formula is: ;in, is the predicted resistance value of the grounding resistor; It is the ground resistance value obtained at the current moment.

[0111] For example, suppose the ground resistance value measured at the current moment is 55 , and according to the model's prediction, the changing trend of the line tower grounding resistance For 3 (i.e. the predicted grounding resistance will increase by 3 ohms), then the predicted resistance value of the grounding resistance is If the change trend of the grounding resistance of the road tower -4 (i.e. the predicted grounding resistance will decrease by 4 ohms), then the predicted resistance value of the grounding resistance is .

[0112] The method of comparing the predicted resistance value of the grounding resistance with the preset resistance threshold of the grounding resistance to determine whether the grounding resistance of the line tower is in a dangerous range includes:

[0113] If the predicted resistance value of the grounding resistance is greater than or equal to the preset resistance threshold of the grounding resistance, it is determined that the grounding resistance of the line tower is in a dangerous range;

[0114] If the predicted resistance value of the grounding resistance is less than the preset resistance value of the grounding resistance, it is determined that the grounding resistance of the line tower is not in a dangerous range.

[0115] If the grounding resistance of the line tower is in a dangerous range, the method of using the resistance measurement intelligent terminal to issue an audible and visual alarm and display the specific location of the tower includes:

[0116] The resistance measurement intelligent terminal automatically triggers the sound and light alarm; the sound and light alarm includes an audible alarm and a flashing warning light; the audible alarm emits a continuous high-frequency alarm sound through a buzzer; the flashing warning light emits an obvious warning signal through an LED flashing light; the GPS positioning technology is used to obtain and display in real time the specific location of the tower where the grounding resistance abnormality occurs.

[0117] The preset resistance threshold of the grounding resistance is set by the staff. Different grounding resistance values ​​are obtained through the resistance measurement intelligent terminal, and the average value of multiple grounding resistance values ​​is taken as the preset resistance threshold of the grounding resistance.

[0118] In this embodiment, by dynamically adjusting the priority and switching state of the grounding line, the switching logic is optimized according to the actual environmental parameters and the historical test data of the line to ensure that it can adapt to different scenarios and needs; using the global control signal and priority mechanism, the grounding line can be quickly switched to reduce the time and resources required for testing, especially when multiple grounding lines are involved at the same time; the priority is dynamically adjusted based on the importance of the grounding line, so that the key lines can be tested first, resources can be reasonably allocated, and the test effect can be improved;

[0119] Comprehensively consider environmental parameters (such as soil temperature, humidity, conductivity, etc.) and the degree of ground electrode corrosion to ensure that the collected current and voltage data are comprehensive and accurate in different environments; use importance formulas and matrix representation to systematize and standardize complex line switching and priority control systems to facilitate subsequent data analysis and decision-making; by defining the target optimization function, the total switching time of the ground line is minimized, reducing the system response time problem caused by switching delays and improving the real-time performance of the test;

[0120] The combination of historical test data and current environmental parameters not only facilitates real-time monitoring, but also enables predictions of future grounding line performance and reliability. Resource limitation constraints are introduced to ensure that switching operations within the same time period do not exceed the maximum parallel switching capacity of the normally closed contactor to avoid resource overload and conflict. Switching resources are reasonably allocated while minimizing switching time to avoid performance degradation or system failure due to insufficient or excessive use of resources.

[0121] Example 2

[0122] See also Figure 2 As shown, the part not described in detail in this embodiment is described in Example 1, which provides a method for measuring the grounding resistance of a tower in a grounding ring network, including:

[0123] S1. Switch the grounding circuit through a normally closed contactor, and collect the current and voltage values ​​of the grounding circuit in different switching states under different environments;

[0124] S2. Based on the current values ​​and voltage values ​​of the grounding lines in different switching states under different environments, the grounding resistance values ​​in different grounding lines are calculated; the grounding resistance values ​​in different grounding lines are preprocessed to obtain grounding resistance data sets in different grounding lines;

[0125] S3, training a line tower grounding resistance prediction model based on grounding resistance data sets in different grounding lines, and predicting the change trend of the line tower grounding resistance through the line tower grounding resistance prediction model;

[0126] S4. According to the change trend of the grounding resistance of the line tower, the predicted resistance value of the grounding resistance is obtained;

[0127] S5, comparing the predicted resistance value of the grounding resistance with the predicted resistance threshold of the grounding resistance to determine whether the grounding resistance of the line tower is in a dangerous range;

[0128] S6. If the grounding resistance of the line tower is within the dangerous range, the resistance measurement intelligent terminal will give an audible and visual alarm and display the specific location of the tower.

[0129] Since the electronic device introduced in this embodiment is an electronic device used to implement the measurement system and method of the grounding resistance of a pole tower in a grounding ring network in the embodiment of the present application, based on the measurement system and method of the grounding resistance of a pole tower in a grounding ring network introduced in the embodiment of the present application, the technical personnel of the field can understand the specific implementation of the electronic device of the present embodiment and its various variations, so how the electronic device implements the method in the embodiment of the present application is not described in detail here. As long as the technical personnel of the field implement the electronic device used by the measurement system and method of the grounding resistance of a pole tower in a grounding ring network in the embodiment of the present application, it belongs to the scope of protection of this application.

[0130] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters and thresholds in the formula are set by technicians in this field according to actual conditions.

[0131] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technical users in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A system for measuring the grounding resistance of a tower in a grounding ring network, characterized in that: include: A data acquisition module, used to obtain current values ​​and voltage values ​​of the grounding line in different switching states under different environments; A first data processing module is used to calculate the grounding resistance values ​​in different grounding lines according to the current values ​​and voltage values ​​of the grounding lines in different switching states under different environments; Preprocessing the grounding resistance values ​​in different grounding lines to obtain grounding resistance data sets in different grounding lines; The resistance change prediction module is used to train and obtain a line tower grounding resistance prediction model based on the grounding resistance data sets in different grounding lines, and predict the change trend of the line tower grounding resistance through the line tower grounding resistance prediction model; The second data processing module is used to obtain the predicted resistance value of the grounding resistance according to the change trend of the grounding resistance of the line tower; A resistance judgment module is used to compare the predicted resistance value of the grounding resistance with the preset resistance threshold of the grounding resistance to judge whether the grounding resistance of the line tower is in a dangerous range; Danger alarm module: if the grounding resistance of the line tower is in a dangerous range, an audible and visual alarm will be issued through the resistance measurement intelligent terminal, and the specific location of the tower will be displayed; each module is connected by wire and / or wireless means; The method for obtaining the current value and voltage value of the grounding circuit in different switching states under different environments includes: S21. Switch the grounding line through the normally closed contactor, and collect the current and voltage values ​​of the grounding line in different switching states under different environments; there are m grounding lines preset, and the switching state of each grounding line is determined by the global control signal and the grounding line priority; the switching state of each grounding line is expressed as: A j =S t ·p j Among them, A j is the switching state of the jth grounding line, A j ∈{0,1},A j When it is 1, it means the ground line is switched, A j When it is 0, it means that the grounding circuit is not switched; S t is the global control signal, S t ∈{0,1},S t When it is 1, it means that the ground line is allowed to switch, S t When it is 0, it means that the ground line is not allowed to switch; j is the priority of the jth grounding line, p j When it is 1, it means that the ground line switching is allowed. j When it is 0, it means that the ground line switching is not allowed. j ∈{0,1}; j is the index of the switching state of the ground line, j=1,2,...,m; t is the timing step of the global control signal; When the global control signal S t is 1 and the ground line priority p j When it is 1, the ground line j is switched; S22, priority p of the jth grounding line j The distribution of is dynamically adjusted according to the importance of the grounding line; the importance of the jth grounding line is preset as ω j , then the priority of the jth grounding line is p j Defined as: Among them, ω z is a preset threshold value of importance of the grounding line; The importance of the grounding line is calculated as follows: j =α·E j +β·D j ; E j is the comprehensive value of the current environmental parameters of grounding line j; D j is the frequency of occurrence of grounding line j in historical tests; α is the weight coefficient for balancing the impact of the comprehensive value of current environmental parameters on the importance of the grounding line; β is the weight coefficient for balancing the impact of the frequency of occurrence of the grounding line in historical tests on the importance of the grounding line; The current environmental parameters include soil temperature, soil moisture, soil conductivity and ground electrode corrosion degree; the comprehensive value of the current environmental parameters of ground line j is expressed as: E j =δ1·T j +δ2·H j +δ3·G j +δ4·C j ; Among them, T j is the soil temperature of the area where the grounding line j is located; H j is the soil moisture in the area where the grounding line j is located; G j is the soil conductivity of the area where the grounding line j is located; C j is the corrosion degree of the grounding electrode in the area where the grounding line j is located; δ1 is the soil temperature weight factor in the area where the grounding line j is located; δ2 is the soil moisture weight factor in the area where the grounding line j is located; δ3 is the soil conductivity weight factor in the area where the grounding line j is located; δ4 is the grounding electrode corrosion degree weight factor in the area where the grounding line j is located; The frequency of occurrence of ground line j in historical tests is expressed as: Among them, N j N is the number of tests that ground line j participated in in historical tests; tol is the total number of historical tests; S23. Use a matrix to represent the switching status and priority of all grounding lines. The switching status matrix of all grounding lines is represented as: A = [A1, A2, ..., A j ,...,A m ]; among them, A m is the switching state of the mth grounding line; m is the number of grounding lines; the priority matrix of all grounding lines is expressed as: P = [p1, p2, ..., p j ,...,p m ]; S24. Define the total switching time of the grounding line as: T sw =max j∈{1,2,...,m} (t ja +t jb ), where T sw is the total switching time of the grounding line; t ja is the start-up delay time of the grounding circuit; t jb is the actual switching time of the grounding line; max j∈{1,2,...,m} is the maximization operator, which means finding the maximum value of the sum of the start-up delay time and the switching operation time among all grounding lines; S25. Define the target optimization function to minimize the total switching time of the grounding line; switch all grounding lines, dynamically adjust the switching state of the grounding line through the joint control of the switching state matrix A and the priority matrix P, and collect and obtain the current value and voltage value of each grounding line under different environments.

2. The system for measuring the grounding resistance of a tower in a grounding ring network according to claim 1, characterized in that: The method of defining the target optimization function to minimize the total switching time of the grounding line includes: Define a target optimization function to adjust the global control signal S t and the priority matrix P to minimize the total switching time of the grounding line; the objective optimization function is: in, is the shortest total switching time for the grounding line; To adjust the global control signal S t and the priority matrix P, so that the total switching time of the ground line is minimized; Define the constraints of the target optimization function, which include resource limitation constraints and priority limitation constraints; the resource limitation constraint is that in the same time period, the total number of grounding lines allowed to be switched is less than or equal to the maximum number of parallel switching supported by the normally closed contactor; The resource limit constraint expression is: in, K is the total number of grounding circuits being switched among all grounding circuits in the same time period; max The maximum number of parallel switching supported by the normally closed contactor; is the switching state of the j-th ground line in the global control signal; t' is the index of the time at which the switching state of the j-th ground line in the global control signal is located; The precedence restriction constraint expression is: Indicates that the ground lines in the priority matrix must be ground lines allowed by the global control signal.

3. The system for measuring the grounding resistance of a tower in a grounding ring network according to claim 2, characterized in that: The method for calculating the grounding resistance values ​​in different grounding circuits according to the current values ​​and voltage values ​​of the grounding circuits in different switching states under different environments includes: It is assumed that the current and voltage values ​​under L different environments are obtained. There are m grounding lines in total. The current value of the jth grounding line under the qth environment is defined as I j,q , the voltage value of the jth ground line in the qth environment is V j,q ; According to Ohm's law, the resistance of the jth grounding line in the qth environment is calculated to be 4. The system for measuring the grounding resistance of a tower in a grounding ring network according to claim 3, characterized in that: The method of preprocessing the grounding resistance values ​​in different grounding lines to obtain the grounding resistance data sets in different grounding lines includes: The OPTICS algorithm is used to identify and eliminate the abnormal values ​​in the grounding resistance values ​​in different grounding lines. The grounding resistance values ​​in different grounding lines after eliminating the abnormal values ​​are subjected to wavelet transform denoising and feature extraction to obtain the grounding resistance data set in different grounding lines. The grounding resistance data sets in different grounding lines are normalized by standard deviation and converted into standard normal distribution to obtain the normalized grounding resistance data sets in different grounding lines.

5. The system for measuring the grounding resistance of a tower in a grounding ring network according to claim 4, characterized in that: The training method of the line tower grounding resistance prediction model includes: The data set is divided into a training set, a test set and a validation set, and a line tower grounding resistance prediction model is constructed; the sample set is a subset of the data set, and each sample set includes a grounding resistance data set in different historical grounding lines and a corresponding change trend of the line tower grounding resistance; the input data of the model is a grounding resistance data set in different historical grounding lines; the output label is a change trend of the line tower grounding resistance; the line tower grounding resistance prediction model is a random forest regression model; Initialize the line tower grounding resistance prediction model and set the number and depth hyperparameters of the tree. Use the training set to train the line tower grounding resistance prediction model, use the test set data to evaluate the performance of the model, and use the determination coefficient to evaluate the difference between the calculated prediction result and the true label. According to the performance feedback of the validation set, the number and depth hyperparameters of the trees are adjusted to tune the model. The model is retrained using the adjusted hyperparameters. The training is stopped when the performance index of the validation set reaches the preset performance index threshold or the model performance no longer improves, and the final trained line tower grounding resistance prediction model is obtained. The trained line tower grounding resistance prediction model is used to predict the grounding resistance data sets in the current different grounding lines to predict the changing trend of the line tower grounding resistance.

6. The system for measuring the grounding resistance of a tower in a grounding ring network according to claim 5, characterized in that: The method for obtaining the predicted resistance value of the grounding resistance according to the change trend of the grounding resistance of the line tower includes: The change trend of the line tower grounding resistance is preset to ΔR, and the predicted resistance value of the grounding resistance is calculated by the grounding resistance prediction formula; the grounding resistance prediction formula is: R pred =R al +ΔR; where R pred is the predicted resistance value of the grounding resistor; R al It is the ground resistance value obtained at the current moment.

7. The system for measuring the grounding resistance of a tower in a grounding ring network according to claim 6, characterized in that: The method of comparing the predicted resistance value of the grounding resistance with the preset resistance threshold of the grounding resistance to determine whether the grounding resistance of the line tower is in a dangerous range includes: If the predicted resistance value of the grounding resistance is greater than or equal to the preset resistance threshold of the grounding resistance, it is determined that the grounding resistance of the line tower is in a dangerous range; If the predicted resistance value of the grounding resistance is less than the preset resistance value of the grounding resistance, it is determined that the grounding resistance of the line tower is not in a dangerous range.

8. The system for measuring the grounding resistance of a tower in a grounding ring network according to claim 7, characterized in that: If the grounding resistance of the line tower is in a dangerous range, the method of using the resistance measurement intelligent terminal to give an audible and visual alarm and display the specific location of the tower includes: The resistance measurement intelligent terminal automatically triggers the sound and light alarm; the sound and light alarm includes an audible alarm and a flashing warning light; the audible alarm emits a continuous high-frequency alarm sound through a buzzer; the flashing warning light emits an obvious warning signal through an LED flashing light; the GPS positioning technology is used to obtain and display in real time the specific location of the tower where the grounding resistance abnormality occurs.

9. A method for measuring the grounding resistance of a tower in a grounding ring network, applied to a system for measuring the grounding resistance of a tower in a grounding ring network as claimed in any one of claims 1 to 8, characterized in that: include: S1. Switch the grounding circuit through a normally closed contactor, and collect the current and voltage values ​​of the grounding circuit in different switching states under different environments; S2. Based on the current values ​​and voltage values ​​of the grounding circuits in different switching states under different environments, the grounding resistance values ​​in different grounding circuits are calculated; Preprocessing the grounding resistance values ​​in different grounding lines to obtain grounding resistance data sets in different grounding lines; S3, training a line tower grounding resistance prediction model based on grounding resistance data sets in different grounding lines, and predicting the change trend of the line tower grounding resistance through the line tower grounding resistance prediction model; S4. According to the change trend of the grounding resistance of the line tower, the predicted resistance value of the grounding resistance is obtained; S5, comparing the predicted resistance value of the grounding resistance with the preset resistance threshold of the grounding resistance to determine whether the grounding resistance of the line tower is in a dangerous range; S6. If the grounding resistance of the line tower is within the dangerous range, the resistance measurement intelligent terminal will give an audible and visual alarm and display the specific location of the tower.

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