A corona field delay-type lightning rod and its operation monitoring method

Abstract

This application relates to the field of lightning rod lightning protection monitoring technology, specifically to a corona field delayed lightning rod and its operation monitoring method. The method includes: collecting corona current and electric field intensity at each moment within each monitoring cycle during the operation of the lightning rod; calculating the first evaluation value and electric field anomaly degree for each time period in each monitoring cycle to obtain the first interference degree for each time period in each monitoring cycle; determining the second evaluation value and cycle anomaly degree for each time period in each monitoring cycle to obtain the second interference degree for each time period in each monitoring cycle; determining the interference coefficient for each monitoring cycle; and evaluating the data distortion status monitored during the operation of the lightning rod. This application, by evaluating the monitored data distortion status, reduces the possibility of misjudgment or omission of lightning strike risk by the lightning rod, and improves the accuracy of assessing the strength of corona discharge generated by the corona field delayed lightning rod under the action of the electric field and the activity of thunderclouds.

Description

Technical Field

[0001] This application relates to the field of lightning rod lightning protection monitoring technology, specifically to a corona field delay type lightning rod and its operation monitoring method. Background Technology

[0002] Corona field delay lightning rods, as active lightning protection devices, interfere with the lightning propagation process by forming an ion layer through corona discharge, thereby expanding the protection range and reducing the risk of lightning strikes. Their core function lies in using the release of corona ions to suppress or delay the triggering of the upward leader and prevent the establishment of the lightning channel. Monitoring the operation of corona field delay lightning rods aims to accurately understand the corona ion release status, electric field response, and equipment operating status, providing effective data support for addressing lightning strike accidents caused by protection failure, extending equipment lifespan, and optimizing lightning protection strategies.

[0003] Traditional lightning rod operation monitoring technologies still have certain drawbacks. For example, when the wind speed is too high, the corona ion layer formed by the corona discharge of the lightning rod will be blown away, destroying the stability of the corona ion layer and causing local electric field distortion. Secondly, high ambient humidity will cause a conductive water film to form on the surface of the lightning rod, increasing the surface leakage current and thus masking the true corona current. This will distort the monitoring data of the corona field delay lightning rod, making it impossible to accurately reflect the actual operating status of the lightning rod and increasing the possibility of misjudgment or omission of lightning strike risk. Summary of the Invention

[0004] To address the aforementioned technical problems, a corona field delay lightning rod and its operation monitoring method are provided to resolve the existing issues.

[0005] The solution to the technical problem presented in this application is to provide a corona field delay-type lightning rod and an operation monitoring method, including the following steps:

[0006] In a first aspect, embodiments of this application provide a method for monitoring the operation of a corona field delayed lightning rod, the method comprising the following steps:

[0007] The corona current and electric field intensity are collected at each moment during each monitoring cycle of the lightning rod operation; and all moments in each monitoring cycle are divided into multiple time periods.

[0008] Frequency domain analysis was performed on all corona currents in each time period to obtain the spectrum and power spectrum; the proportion of the power spectral density of the high-frequency components in the power spectrum and the extreme changes in the corona current were analyzed, and the first evaluation value of each time period in each monitoring cycle was calculated.

[0009] The abnormal situation of synchronous change of electric field intensity and corona current at different times in each time period is analyzed, as well as the discrete situation of electric field intensity. The electric field anomaly degree of each time period in each monitoring cycle is calculated. Combined with the first evaluation value, the first interference degree of each time period in each monitoring cycle is obtained.

[0010] The second evaluation value for each time period in each monitoring cycle is determined by the difference in the peak and trough of the corona current at all times in each time period, and the energy dispersion of the low-frequency components in the spectrum.

[0011] Based on the variation of the time interval between the peak and trough of the corona current at all times in each time period, and the correlation of the periodicity of the corona current, the periodicity of each time period in each monitoring cycle is calculated, and combined with the second evaluation value, the second interference degree of each time period in each monitoring cycle is obtained.

[0012] Based on the first and second interference levels for all time periods, the interference coefficient for each monitoring cycle is determined, and the data distortion monitored during the operation of the lightning rod is evaluated.

[0013] Preferably, the calculation of the first evaluation value for each time period in each monitoring cycle includes:

[0014] The frequency components in the spectrum and the power spectrum that are greater than a preset frequency are respectively denoted as high-frequency components, and vice versa, they are denoted as low-frequency components.

[0015] The ratio between the sum of the power spectral densities of all high-frequency components in the power spectrum and the sum of the power spectral densities of all frequency components is denoted as the high-frequency proportion.

[0016] The product of the range and mean of the corona current at all times within each time period of each monitoring cycle is denoted as the volatility.

[0017] The first evaluation value is the product of the volatility and the proportion of high frequency.

[0018] Preferably, the calculation of the electric field anomaly degree for each time period in each monitoring cycle includes:

[0019] The ratio of electric field intensity to corona current at each moment is denoted as the instantaneous field-current ratio; curve fitting is performed on the instantaneous field-current ratio at all moments within each time period of each monitoring cycle, and the curvature of the fitted curve at each moment is calculated.

[0020] The product of the mean and variance of the curvature at all times within each time period is denoted as the nonlinear intensity.

[0021] Calculate the degree of dispersion of the electric field intensity at all times within each time period, and denote it as the first degree of dispersion;

[0022] The electric field anomaly is the product of the nonlinear intensity and the first discreteness.

[0023] Preferably, the first interference degree is the product of the first evaluation value and the electric field anomaly degree.

[0024] Preferably, determining the second evaluation value for each time period in each monitoring cycle includes:

[0025] Calculate the degree of energy dispersion of all low-frequency components in the spectrum, and denote it as the second degree of dispersion;

[0026] Obtain the peaks and troughs of the corona current at all times within each time period of each monitoring cycle;

[0027] Calculate the time interval between the time corresponding to each peak and the time corresponding to each trough, and select the trough with the smallest time interval from each peak as the neighboring trough.

[0028] Calculate the difference between the peak value of each wave peak and the valley value of its neighboring wave trough, and record it as the reference value of each wave peak;

[0029] Calculate the sum of the differences between the reference values ​​between any two adjacent peaks within each time period of each monitoring cycle;

[0030] The second evaluation value is the product of the result of the positive mapping of the sum and the second discreteness.

[0031] Preferably, the calculation of the periodic anomaly degree for each time period in each monitoring cycle includes:

[0032] For each monitoring period, calculate the autocorrelation coefficients of the corona current at all times within each time period for multiple lag orders; calculate the mean of the autocorrelation coefficients corresponding to all lag orders within each time period, and denot it as the correlation degree.

[0033] The duration between the time corresponding to each wave peak and the time corresponding to its nearest wave trough is denoted as the half-width.

[0034] Calculate the sum of the differences in half-width between any two adjacent peaks within each time period;

[0035] The periodic anomaly is the product of the result of positive mapping of the sum and the correlation.

[0036] Preferably, the second disturbance degree is the product of the periodic anomaly degree and the second evaluation value.

[0037] Preferably, the interference coefficient is the normalized result of the mean of the product of the first interference degree and the second interference degree for all time periods in each monitoring cycle.

[0038] Preferably, the evaluation of the data distortion monitored during the operation of the lightning rod includes: if the interference coefficient is less than a preset threshold, the data monitored by the lightning rod in this monitoring period is not distorted; otherwise, the data monitored by the lightning rod is distorted.

[0039] Secondly, this application also provides a corona field delay type lightning rod, which includes a lightning rod 101, a corona needle 102, a side needle 103, a strong ionization discharge unit 104, a base 105, an inductive resonator 106, and an online grounding resistance monitor 107.

[0040] This application has at least the following beneficial effects:

[0041] This application performs frequency domain analysis on the corona current, calculates the first evaluation value for each time period in each monitoring cycle based on the proportion of high-frequency components in the power spectrum and the extreme changes in the corona current. Its beneficial effect lies in considering the obvious high-frequency oscillation characteristics of the corona current, indicating the destruction of the corona ion layer generated by the corona field delay-type lightning rod, reflecting the possibility of corona ion layer imbalance and the instability of the corona current, thus providing a preliminary assessment of the interference of the lightning rod with ambient wind speed. Secondly, by considering the abnormal synchronous changes in electric field strength and corona current, and the discrete distribution of electric field strength, the electric field anomaly degree for each time period in each monitoring cycle is calculated. Its beneficial effect lies in considering the complexity of electric field strength changes. The anomalies are analyzed to illustrate the degree of electric field distortion. Furthermore, the imbalance between the synchronous changes in corona current and electric field strength is used to further assess the interference of environmental wind speed on the lightning rod. The first interference level for each time period in each monitoring cycle is obtained. Its beneficial effect is to comprehensively assess the extent to which the corona ion layer is damaged by wind disturbances in corona field-delayed lightning rods, and the possibility of corona ion layer imbalance. The second evaluation value for each time period in each monitoring cycle is calculated through the uneven energy distribution of the low-frequency components in the corona current and the differences in the baseline level of the corona current. Its beneficial effect is to consider the complex energy situation of the frequency components of the corona current and the severe baseline drift of the corona current, thus illustrating... The significance of the superposition of different leakage currents caused by the water film formed on the surface of the lightning rod due to humidity is used to preliminarily assess the impact of environmental humidity on the corona current of the lightning rod. Based on the periodic changes in the corona current and the changes in the pulse half-width of the pulse waveform, the periodic anomaly degree of each time period in each monitoring cycle is calculated. Its beneficial effect is that it considers the smoothing of the corona current pulse waveform by the leakage current and the intensity of the periodic changes in the corona current, further reflecting the smoothing of the corona current pulse waveform by the leakage current due to the influence of environmental humidity on the lightning rod surface, thus assessing the interference of environmental humidity on the lightning rod surface. The second interference degree of each time period in each monitoring cycle is determined, and its beneficial effect is... This study comprehensively assesses the degree to which the conductive water film formed on the surface of a lightning rod is affected by environmental humidity interference; determines the interference coefficient for each monitoring cycle; and evaluates the data distortion monitored during the operation of the lightning rod. Its beneficial effect lies in its ability to accurately reflect the degree to which the corona current ion layer generated by the corona-delayed lightning rod is damaged by wind speed and the superimposed effect of leakage current caused by environmental humidity. This allows for the evaluation of data distortion monitored by the corona-delayed lightning rod, thereby reducing the possibility of misjudgment or omission of lightning strike risk, improving the accuracy of assessing the strength of corona discharge generated by the corona-delayed lightning rod under the action of an electric field and the activity of thunderclouds, and enhancing its accuracy and reliability in lightning protection. Attached Figure Description

[0042] The following description, in conjunction with the accompanying drawings, provides a more detailed explanation of a method for monitoring the operation of a corona field delay-type lightning rod according to this application.

[0043] Figure 1 A flowchart illustrating the steps of a method for monitoring the operation of a corona field delayed lightning rod, as provided in this application embodiment;

[0044] Figure 2 A flowchart illustrating the steps of the method for obtaining the interference coefficient provided in this application embodiment;

[0045] Figure 3 This is a schematic diagram of the structure of a corona field delay lightning rod provided in an embodiment of this application. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description, in conjunction with the accompanying drawings and embodiments, provides a corona field delay-type lightning rod and its operation monitoring method proposed in this application. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0048] Please see Figure 1 The diagram illustrates a flowchart of a method for monitoring the operation of a corona field delay-type lightning rod according to an embodiment of this application. The method includes the following steps:

[0049] Step 1: Collect the corona current and electric field intensity at each moment during each monitoring cycle of the lightning rod during its operation.

[0050] Lightning protection devices ensure the stable operation of power equipment. In the event of abnormal overvoltage conditions, surge arresters effectively protect the power grid. In power systems, lightning activity can trigger overvoltages, damaging substation equipment, transmission lines, and terminal equipment. Lightning rods guide lightning through tip discharge, causing overvoltages to dissipate into the ground along a predetermined path, preventing equipment damage from overvoltage and ensuring the stability and reliability of the power system.

[0051] Secondly, corona-delay lightning rods suppress or delay the upward leader of a lightning strike through the corona ion layer. The upward leader refers to a discharge path that extends from the ground or a ground protrusion (i.e., the lightning rod) towards the thundercloud. When a thundercloud approaches the ground, it causes electric field distortion on the surface of objects at the ground's tip. When the electric field strength is sufficiently high, reaching the air breakdown threshold, these objects (the lightning rod) emit an upward flow of electrons, thus forming the upward leader. The accuracy of a lightning rod's suppression or delay of the upward leader directly depends on the accuracy of the corona current and the electric field strength at the lightning rod's tip. However, data acquisition is significantly affected by environmental interference. If the data is distorted due to environmental factors such as wind speed and humidity, the suppression effect of the lightning rod will fail, leading to misjudgment of the lightning rod's operating status and an inability to accurately identify potential lightning strike risks, thus affecting the stability of the power system.

[0052] Based on the above analysis, a high-precision corona current sensor and a dual-probe electric field sensor are used to collect the corona current, electric field intensity at the tip of the lightning rod, and ambient humidity during the operation of the corona field delay lightning rod in real time. The collected data are normalized and missing values ​​are filled. Multiple moments are recorded as a monitoring cycle, thereby obtaining the corona current, electric field intensity, and ambient humidity at each moment within each monitoring cycle during the operation of the corona field delay lightning rod.

[0053] In this embodiment, the data acquisition frequency of the corona current sensor and the dual-probe electric field sensor is 100kHz, and the duration of each monitoring cycle is 1min. As for other implementation methods, the implementer can set them according to the actual situation. Secondly, Z-Score standardization is used for normalization processing, and median filling is used for missing value filling. Z-Score standardization and median filling are well-known technologies and will not be described in detail here.

[0054] Thus, the corona current and electric field intensity at each moment in each monitoring cycle during the operation of the corona field delay lightning rod are obtained.

[0055] Step 2: Perform frequency domain analysis on all corona currents in each time period to obtain the spectrum and power spectrum; analyze the proportion of the power spectral density of the high-frequency components in the power spectrum and the extreme changes in the corona current, and calculate the first evaluation value for each time period in each monitoring cycle; analyze the abnormalities in the synchronous changes of electric field strength and corona current at different times in each time period, as well as the dispersion of electric field strength, and calculate the electric field anomaly degree for each time period in each monitoring cycle. Combined with the first evaluation value, obtain the first interference degree for each time period in each monitoring cycle.

[0056] During the operation of corona field delayed lightning rods, the corona current directly reflects the strength of the corona discharge generated by the lightning rod under the influence of the thundercloud electric field. The release of corona ions can inhibit or delay the triggering of the upward lightning leader and reduce the risk of lightning channel establishment, thereby preventing lightning strike risks. However, thundercloud electric fields are usually accompanied by severe meteorological factors, such as ambient wind speed, which can cause imbalance in the corona ion layer and lead to distortion of the electric field, resulting in misjudgments or omissions in the monitoring of corona field delayed lightning rod operation.

[0057] The greater the interference from ambient wind speed, the higher the degree of damage to the corona ion layer, resulting in increased fluctuations in the corona current. The corona discharge intensity weakens as the ion density decreases, and the average level of the corona current is higher. Furthermore, due to the electric field distortion and space charge distribution instability caused by the dissipation region of the corona ion layer, the random local discharge pulses increase, leading to a significant high-frequency oscillation characteristic in the corona current. At the same time, the electric field strength and corona current are positively correlated by the ionization efficiency and the dynamic balance of space charge. However, the wind disturbance makes the time synchronization correlation between the corona current and the electric field strength worse, and the abnormal fluctuations in the electric field strength are more obvious.

[0058] Based on the above analysis, the first disturbance degree is calculated by observing the abnormal changes in corona current and electric field strength, which is used to characterize the abnormal changes in corona current and electric field strength caused by wind speed.

[0059] First, the fluctuation of the corona current and its high-frequency oscillation characteristics are analyzed, and the first evaluation value is calculated, specifically:

[0060] Divide all moments within each monitoring cycle into multiple time periods;

[0061] In this embodiment, the duration of each time period is 1ms. As for other implementation methods, the implementer can set the duration according to the actual situation.

[0062] Frequency domain analysis was performed on the corona current at all times within each time period of each monitoring cycle to obtain the spectrum and power spectrum;

[0063] In this embodiment, the Fast Fourier Transform (FFT) is used to obtain the spectrum and power spectrum. The FFT is a well-known technique and will not be described in detail here. As other implementation methods, implementers can use other methods of the prior art, such as the Hilbert-Huang Transform. This embodiment does not impose any special restrictions on this.

[0064] The frequency components in the spectrum and the power spectrum that are greater than a preset frequency are respectively denoted as high-frequency components, and vice versa, they are denoted as low-frequency components.

[0065] In this embodiment, the preset frequency is 10kHz. Frequency components in the frequency range of 10kHz to 40kHz are denoted as high-frequency components, and frequency components in the power spectrum less than 10kHz are denoted as low-frequency components. As for other implementation methods, the implementer can set them according to the actual situation.

[0066] The ratio between the sum of the power spectral densities of all high-frequency components in the power spectrum and the sum of the power spectral densities of all frequency components is denoted as the high-frequency proportion.

[0067] It should be noted that the acquisition of power spectral density is a well-known technique and will not be elaborated upon here.

[0068] The product of the range and mean of the corona current at all times within each time period of each monitoring cycle is denoted as the volatility.

[0069] The product of the volatility and the high-frequency ratio is used as the first evaluation value for each time period in each monitoring cycle;

[0070] It should be noted that the higher the proportion of high frequency, the more obvious the high frequency oscillation characteristics of the corona current; the greater the fluctuation, the more violent the fluctuation of the corona current and the relatively greater the intensity of the corona discharge; the higher the obtained first evaluation value, the higher the degree of damage to the corona ion layer of the lightning rod, the greater the possibility of corona ion layer imbalance, and the more prominent the instability of the corona current.

[0071] Secondly, we analyze the abnormal situations of synchronous changes in electric field strength and corona current, as well as the fluctuations in electric field strength, and calculate the degree of electric field anomaly. Specifically:

[0072] The ratio of electric field intensity to corona current at each moment within each time period of each monitoring cycle is denoted as the instantaneous field-current ratio.

[0073] Curve fitting is performed on the instantaneous field flow ratio at all times within each time period, and the curvature of the fitted curve at each time is calculated.

[0074] In this embodiment, the least squares method is used for curve fitting. The least squares method and the calculation of curvature are well-known techniques and will not be described in detail here.

[0075] The degree of dispersion of the electric field intensity at all times within each time period in each monitoring cycle is calculated and denoted as the first degree of dispersion;

[0076] In this embodiment, the degree of dispersion is measured by calculating the approximate entropy of the electric field intensity at all times within each time period in each monitoring cycle. The process of calculating the approximate entropy is a well-known technique and will not be described in detail here.

[0077] The product of the mean and variance of the curvature at all times within each time period is denoted as the nonlinear intensity.

[0078] The product of the nonlinear intensity and the first discreteness is used as the electric field anomaly degree for each time period in each monitoring cycle.

[0079] It should be noted that the larger the first dispersion, the more complex and abnormal the change in electric field strength, and the more interference factors it may be subject to, thus causing distortion of the electric field; the larger the nonlinear intensity, the more unstable the change in the ratio between corona current and electric field strength, reflecting the more significant imbalance between the synchronous change of corona current and electric field strength, the greater the resulting electric field anomaly, indicating that it is severely affected by wind field disturbances and the higher the degree of damage to the corona ion layer of the lightning rod.

[0080] Furthermore, based on the first evaluation value and the electric field anomaly degree, the first interference degree is calculated, specifically as follows:

[0081] The product of the first evaluation value and the electric field anomaly is used as the first interference degree for each time period in each monitoring cycle;

[0082] It should be noted that the greater the first interference degree, the more significant the damage to the corona ion layer caused by wind field disturbance to the corona field delayed lightning rod, and the greater the possibility of corona ion layer imbalance.

[0083] Thus, the first interference degree for each time period in each monitoring cycle is obtained.

[0084] Step 3: By analyzing the differences in peak and trough values ​​in the corona current at all times within each time period, and the energy dispersion of low-frequency components in the spectrum, determine the second evaluation value for each time period in each monitoring cycle. Based on the differences in the time interval between peak and trough values ​​in the corona current at all times within each time period, and the correlation of the periodicity of the corona current, calculate the periodic anomaly degree for each time period in each monitoring cycle. Combined with the second evaluation value, obtain the second interference degree for each time period in each monitoring cycle.

[0085] In the operation of corona field delayed lightning rods, relying solely on the first level of interference to assess the operating status of the lightning rod still has certain shortcomings. It does not take into account the interference caused by the environmental humidity factor in the thundercloud electric field. If the interference from the environmental humidity is greater, it will lead to the formation of a conductive water film on the surface of the lightning rod. The water film will form a low impedance channel, increasing the surface leakage current. This leakage current is highly coupled with the corona current generated by the lightning rod in the time domain, causing the real corona current to be masked.

[0086] When the interference from ambient humidity is significant, the more severe the formation of a conductive water film on the lightning rod surface, the more severe the unevenness of the water film causes different leakage current paths for the corona current on the lightning rod surface. This results in a more complex frequency composition of the corona current, greater differences between the low-frequency components formed by the obstruction and binding of charged ions by water molecules in the water film, and a more pronounced increase in the baseline level of the corona current due to leakage current superposition. Simultaneously, the more severe the smoothing of the corona current pulse waveform by the leakage current, the more obvious the periodic changes in the corona current, and the more significant the increase in the half-width of the corona current pulse waveform. Therefore, a second interference degree is calculated to characterize the leakage current superposition caused by the water film on the lightning rod surface and the smoothing of the corona current waveform.

[0087] First, the variation of the corona current in the low-frequency components and the distribution of different peaks in the corona current are analyzed to calculate the second evaluation value, specifically:

[0088] Obtain the peaks and troughs of the corona current at all times within each time period of each monitoring cycle;

[0089] In this embodiment, the AMPD (Automatic Multiscale-based Peak Detection) algorithm is used to obtain peaks and troughs. The AMPD algorithm is a well-known technology and will not be described in detail here.

[0090] Calculate the time interval between the time corresponding to each peak and the time corresponding to each trough, and select the trough with the smallest time interval from each peak as the neighboring trough.

[0091] The duration between the time corresponding to each wave peak and the time corresponding to its nearest wave trough is denoted as the half-width.

[0092] Calculate the difference between the peak value of each wave peak and the valley value of its neighboring wave trough, and record it as the reference value of each wave peak;

[0093] Calculate the sum of the differences between the reference values ​​between any two adjacent peaks within each time period of each monitoring cycle;

[0094] In this embodiment, the sum of the absolute values ​​of the differences between the reference values ​​between any two adjacent peaks in each time period of each monitoring cycle is calculated.

[0095] Calculate the degree of energy dispersion of all low-frequency components in the spectrum, and denote it as the second degree of dispersion;

[0096] In this embodiment, the degree of dispersion is measured by calculating the variance of the energy of all low-frequency components in the spectrum. As another implementation, the implementer may use other methods of the prior art, such as standard deviation, etc. This embodiment does not impose any special restrictions on this.

[0097] A positive mapping is performed on the accumulated sum, and the product of the positive mapping result and the second dispersion is used as the second evaluation value for each time period in each monitoring cycle;

[0098] In this embodiment, the specific process of positive mapping is as follows: positive mapping is performed through an exponential function, assuming the summation is denoted as... ,Will The result is taken as the result of the positive mapping, where, It is an exponential function with the natural constant as the base.

[0099] It should be noted that the larger the second dispersion, the more uneven the energy distribution of the low-frequency components, the more complex the frequency components of the corona current, and the more significant the non-uniformity of the leakage current path caused by the influence of environmental humidity. The larger the result of the positive mapping, the more severe the baseline drift of the corona current, and the more serious the superposition effect of leakage current. Through positive mapping, the cumulative effect of this change is further amplified. The larger the second evaluation value, the more discrete the energy distribution of the low-frequency components of the lightning rod corona current caused by the interference of environmental humidity, and the more drastic the change in the baseline level of the corona current, reflecting the more serious superposition of different leakage currents formed on the surface of the lightning rod.

[0100] Secondly, the periodic variation characteristics of the corona current and the interval of pulse occurrence are analyzed to calculate the periodic anomaly degree, specifically:

[0101] Calculate the autocorrelation coefficients of the corona current at all times within each time period of each monitoring cycle for multiple hysteresis orders;

[0102] In this embodiment, the autocorrelation coefficients of the corona current at all times within each time period in each monitoring cycle are calculated for hysteresis orders of 10 to 30. As for other implementation methods, the implementer can set them according to the actual situation. It should be noted that the calculation of autocorrelation coefficients is a well-known technique and will not be described in detail here.

[0103] Calculate the mean of the autocorrelation coefficients corresponding to all lag orders, and denote it as the correlation degree;

[0104] Calculate the sum of the differences in half-width between any two adjacent peaks in each time period of each monitoring cycle, perform a positive mapping on the sum, and multiply the result of the positive mapping with the correlation degree as the periodic anomaly degree of each time period in each monitoring cycle.

[0105] In this embodiment, the specific process of positive mapping is as follows: positive mapping is performed through an exponential function, assuming the sum is denoted as... ,Will The result is used as the result of a positive mapping of the sum, where, It is an exponential function with the natural constant as the base.

[0106] It should be noted that the greater the correlation, the more the leakage current smooths the pulse waveform of the corona current when the humidity is high, and the more obvious the periodic change of the corona current is, reflecting the temporal correlation change of the corona current and demonstrating the influence of humidity on the periodicity of the corona current waveform. The larger the sum, the greater the half-width of the corona current pulse waveform caused by the leakage current due to humidity, and the more significant the difference in half-width between different peaks. The greater the periodic anomaly, the greater the influence of humidity interference, and the more severe the smoothing of the corona current pulse waveform by the leakage current.

[0107] Furthermore, based on the periodic anomaly degree and the second evaluation value, the second interference degree is calculated, specifically as follows:

[0108] The product of the periodic anomaly degree and the second evaluation value is used as the second interference degree for each time period in each monitoring cycle.

[0109] It should be noted that the greater the second interference degree, the more severe the superposition of leakage current and the abnormality of corona current waveform caused by environmental humidity interference of the lightning rod, and the more obvious the conductive water film formed on the surface of the lightning rod.

[0110] Thus, the second interference degree for each time period in each monitoring cycle is obtained.

[0111] Step 4: Based on the first and second interference levels for all time periods, determine the interference coefficient for each monitoring cycle and evaluate the data distortion status monitored during the operation of the lightning rod.

[0112] During the operation and monitoring of corona field delayed lightning rods, the stronger the wind speed and the higher the humidity in the thundercloud meteorological environment, the greater the damage of the wind speed to the corona current ion layer of the lightning rod, the more obvious the conductive water film on the surface of the lightning rod caused by the ambient humidity, the more serious the distortion or masking of the collected corona current and ambient electric field, and the more serious the interference of the monitoring data with the meteorological factors of thundercloud activity, the more likely it is to lead to misjudgment and omission of lightning strike risk.

[0113] Based on the above analysis, and based on the first interference level and the second interference level, an interference coefficient is calculated to reflect the interference of environmental meteorological factors on the corona current generated by the lightning rod and the electric field strength in the surrounding area. Specifically:

[0114] The normalized result of the average of the product of the first interference degree and the second interference degree in all time periods of each monitoring period is used as the interference coefficient for each monitoring period.

[0115] In this embodiment, the first The formula for calculating the interference coefficient for each monitoring period is:

[0116]

[0117] in, For the first The interference coefficient for each monitoring period For the first The first monitoring cycle The first level of interference in each time period For the first The first monitoring cycle The second level of interference in each time period, For the first The number of all time periods in a monitoring cycle. The normalization function is the sigmoid function. In this embodiment, the sigmoid function is used for normalization. The sigmoid function is a well-known technology and will not be described in detail here. As other implementation methods, implementers can use other methods of the prior art, such as the softmax function. This embodiment does not impose any special restrictions on this.

[0118] It should be noted that the larger the interference coefficient, the more severe the damage to the corona ion layer of the lightning rod and the more severe the formation of a conductive water film on the surface of the lightning rod during the operation monitoring of the corona field delayed lightning rod. This indicates a stronger interference from wind speed and humidity in the thundercloud electric field environment on the monitoring of the lightning rod's operational status. Consequently, the collected data is subject to greater interference, reflecting the abnormal state of the lightning rod's corona current and the environmental electric field strength caused by the influence of ambient wind speed and humidity during the operation of the corona field delayed lightning rod. The flowchart of the method for obtaining the interference coefficient provided in this application embodiment is shown below. Figure 2 As shown.

[0119] Furthermore, based on the aforementioned interference coefficient, the data distortion of the operation monitoring is evaluated, specifically as follows:

[0120] If the interference coefficient is less than the preset threshold, the data monitored by the lightning rod is not distorted; otherwise, the data monitored by the lightning rod is distorted.

[0121] In this embodiment, the preset threshold value is 0.7. As for other implementation methods, the implementer can set it according to the actual situation.

[0122] It should be noted that when the interference coefficient is less than the preset threshold, the corona ion layer of the corona field delay lightning rod is less affected by wind speed damage, and the ambient humidity makes the leakage current superposition caused by the conductive water film on the surface of the lightning rod unclear. Under this monitoring period, the data monitored by the corona field delay lightning rod is highly reliable. Conversely, the monitoring data of the lightning rod is severely distorted due to the interference of ambient wind speed and humidity. The possibility of misjudgment or omission during the operation and monitoring of the corona field delay lightning rod is high. The suppression or delay effect of the corona field delay lightning rod on the upward leader of lightning strikes is reduced. It is necessary to promptly correct the corona current and electric field strength caused by meteorological interference to provide effective data support for lightning strike accidents caused by protection timeliness and to optimize lightning protection strategies.

[0123] Based on the same inventive concept as the above method, this application also provides a corona field delay type lightning rod, which includes:

[0124] Lightning arresters are responsible for intercepting lightning when the corona ions generated by the delay lightning rod in the corona field cannot be eliminated or suppressed in a short time, thus allowing the lightning current to flow into the ground through the main equipment.

[0125] The corona needle is responsible for generating a corona effect by focusing a suspended high voltage.

[0126] Side strikes are responsible for protection against mine strikes from around and side-strikes.

[0127] The strong ionization discharge unit is responsible for generating a large number of corona ions under the electric field of thunderclouds, forming a corona ion shielding layer above the protected object, suppressing the initiation of the upward leader, weakening the development speed and intensity of the downward leader, and blocking the conduction of the upper and lower channels; thus avoiding direct lightning strikes within the protection range.

[0128] The base is used for support and grounding, and the discharge electrode toothed design increases the voltage and facilitates corona discharge and grounding current.

[0129] Inductive resonator, dispersive waveguide resonant cavity design, waveguide resonant cavity polarity converter to send the ground charge polarity to cavity impedance converter, so that a large number of corona ions can be induced with a low thundercloud electric field.

[0130] The online grounding resistance monitor provides real-time grounding resistance monitoring, facilitating inspections by maintenance personnel, grid connection monitoring, and drone patrols.

[0131] The structural schematic diagram of the corona field delay lightning rod provided in this embodiment is as follows: Figure 3 As shown, 101 is a lightning rod, 102 is a corona rod, 103 is a side rod, 104 is a strong ionization discharge unit, 105 is a base, 106 is an inductive resonator, and 107 is an online grounding resistance monitor.

[0132] It should be understood that, although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0133] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application, without departing from the content of the technical solution of this application, shall fall within the protection scope of the technical solution of this application.

Claims

1. A method for monitoring the operation of a corona field delayed lightning rod, characterized in that, The method includes the following steps: The corona current and electric field intensity are collected at each moment during each monitoring cycle of the lightning rod operation; and all moments in each monitoring cycle are divided into multiple time periods. Frequency domain analysis was performed on all corona currents in each time period to obtain the spectrum and power spectrum. The proportion of the power spectral density of the high-frequency components in the power spectrum and the extreme changes in the corona current are analyzed to calculate the first evaluation value for each time period in each monitoring cycle. The abnormal situation of synchronous change of electric field strength and corona current at different times in each time period is analyzed, as well as the discrete situation of electric field strength. The electric field anomaly degree of each time period in each monitoring cycle is calculated. Combined with the first evaluation value, the first interference degree of each time period in each monitoring cycle is obtained. The first interference degree is the product of the first evaluation value and the electric field anomaly degree. The second evaluation value for each time period in each monitoring cycle is determined by the difference in the peak and trough of the corona current at all times in each time period, and the energy dispersion of the low-frequency components in the spectrum. Based on the variation of the time interval between the peak and trough of the corona current at all times in each time period, and the correlation of the periodicity of the corona current, the periodicity of each time period in each monitoring cycle is calculated. Combined with the second evaluation value, the second interference degree of each time period in each monitoring cycle is obtained. The second interference degree is the product of the periodicity and the second evaluation value. Based on the first and second interference levels for all time periods, the interference coefficient for each monitoring cycle is determined, and the data distortion monitored during the operation of the lightning rod is evaluated. The process of obtaining the first evaluation value is as follows: the frequency components in the spectrum and the power spectrum that are greater than the preset frequency are recorded as high-frequency components, and vice versa, they are recorded as low-frequency components. The ratio between the sum of the power spectral densities of all high-frequency components in the power spectrum and the sum of the power spectral densities of all frequency components is denoted as the high-frequency proportion. The product of the range and mean of the corona current at all times within each time period of each monitoring cycle is denoted as the volatility. The first evaluation value is the product of the volatility and the proportion of high frequency. The process of obtaining the second evaluation value is as follows: calculate the degree of energy dispersion of all low-frequency components in the spectrum, and denot it as the second dispersion. Obtain the peaks and troughs of the corona current at all times within each time period of each monitoring cycle; Calculate the time interval between the time corresponding to each peak and the time corresponding to each trough, and select the trough with the smallest time interval from each peak as the neighboring trough. Calculate the difference between the peak value of each wave peak and the valley value of its neighboring wave trough, and record it as the reference value of each wave peak; Calculate the sum of the differences between the reference values ​​between any two adjacent peaks within each time period of each monitoring cycle; The second evaluation value is the product of the result of the positive mapping of the sum and the second discreteness.

2. The method for monitoring the operation of a corona field delayed lightning rod as described in claim 1, characterized in that, The calculation of the electric field anomaly degree for each time period in each monitoring cycle includes: The ratio of electric field intensity to corona current at each moment is denoted as the instantaneous field-current ratio; curve fitting is performed on the instantaneous field-current ratio at all moments within each time period of each monitoring cycle, and the curvature of the fitted curve at each moment is calculated. The product of the mean and variance of the curvature at all times within each time period is denoted as the nonlinear intensity. Calculate the degree of dispersion of the electric field intensity at all times within each time period, and denote it as the first degree of dispersion; The electric field anomaly is the product of the nonlinear intensity and the first discreteness.

3. The method for monitoring the operation of a corona field delayed lightning rod as described in claim 1, characterized in that, The calculation of the periodic anomaly degree for each time period in each monitoring cycle includes: For each monitoring period, calculate the autocorrelation coefficients of the corona current at all times within each time period for multiple lag orders; calculate the mean of the autocorrelation coefficients corresponding to all lag orders within each time period, and denot it as the correlation degree. The duration between the time corresponding to each wave peak and the time corresponding to its nearest wave trough is denoted as the half-width. Calculate the sum of the differences in half-width between any two adjacent peaks within each time period; The periodic anomaly is the product of the result of positive mapping of the sum and the correlation.

4. The method for monitoring the operation of a corona field delayed lightning rod as described in claim 1, characterized in that, The interference coefficient is the normalized result of the mean of the product of the first interference degree and the second interference degree for all time periods in each monitoring cycle.

5. The method for monitoring the operation of a corona field delayed lightning rod as described in claim 1, characterized in that, The evaluation of the data distortion monitored during the operation of the lightning rod includes: if the interference coefficient is less than a preset threshold, the data monitored by the lightning rod in this monitoring period is not distorted; otherwise, the data monitored by the lightning rod is distorted.

6. A corona field delay-type lightning rod, applied to the operation monitoring method of the corona field delay-type lightning rod as described in claim 1, characterized in that, The corona field delay type lightning rod includes a lightning rod (101), a corona needle (102), a side needle (103), a strong ionization discharge unit (104), a base (105), an inductive resonator (106), and an online grounding resistance monitor (107).

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