Lightning protection equipment for electric power facility and corona current monitoring system thereof

Abstract

The invention relates to the technical field of lightning driving device monitoring, in particular to lightning protection equipment for electric power facilities and a corona current monitoring system of the lightning protection equipment. The theoretical corona current value is obtained according to the change trend of the field intensity data at each moment in the monitoring time period, the ambient air pressure data and the ambient temperature data, and the current data is corrected according to the difference between the fluctuation degree of the current data in each sub-time period of the monitoring time period and the fluctuation degree of the theoretical corona current value. Obtaining current effective data at each moment in the sub-time period; and obtaining a current abnormal value according to the correlation degree between the theoretical corona current value and the current effective data at each moment and all moments in the previous time period, and monitoring the operation state of the lightning driving device based on the current abnormal value at the current moment and the adjacent moment. According to the invention, the monitoring precision of the operation state of the passive corona field lightning expeller is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of lightning drive monitoring, and in particular to a lightning protection device for electric power facilities and a corona current monitoring system thereof. Background Art

[0002] The passive corona field lightning driver is a device used for lightning protection of transmission lines. The electric field lines at the needle tip of the lightning driver are relatively concentrated, making it easier for corona ionization to occur at the tip of the lightning driver. The negative charge ionized at the tip of the lightning driver is absorbed by the ground current collection device, and the positive charge interacts with the negative charge of the thundercloud and slowly neutralizes, thereby weakening the development speed of the downward leader. Therefore, by monitoring the corona current during the operation of the lightning driver, the operating status of the passive corona field lightning driver can be monitored. Monitoring the operating status of the passive corona field lightning driver is of great significance to ensure the safe, stable and efficient operation of the power system.

[0003] Existing methods usually set a preset threshold for the corona current based on the charge production capacity of the corona field generated by the passive corona field lightning driver. When the real-time corona current exceeds the preset threshold, the lightning driver is considered to be in an abnormal operating state. However, environmental factors such as thundercloud field strength, temperature and air pressure affect the ionization level of the positive charge ionized at the tip of the lightning driver, and the collection accuracy of the corona current collection device is prone to errors in complex thundercloud weather, resulting in errors between the current data obtained by the corona current collection device and the actual corona current, and thus the monitoring accuracy of the operating status of the passive corona field lightning driver is low. Summary of the invention

[0004] In order to solve the technical problem that the current data obtained by the corona current acquisition device and the actual corona current have errors, resulting in low monitoring accuracy of the operating status of the passive corona field lightning driver, the purpose of the present invention is to provide a lightning protection device for power facilities and a corona current monitoring system thereof, and the technical scheme adopted is as follows: The present invention proposes a corona current monitoring system for lightning protection equipment of electric power facilities, the system comprising: The data acquisition module is used to obtain the field strength data, current data, ambient air pressure data and ambient temperature data of the lightning drive at each moment in the monitoring time period under thundercloud weather; the last moment in the monitoring time period is the current moment; Theoretical corona current analysis module is used to obtain the theoretical corona current value at each moment in the monitoring period according to the difference between the field strength data at each moment in the monitoring period and the field strength data of the lightning drive in the historical period without thundercloud weather, as well as the change trend of the field strength data at each moment, the ambient air pressure data and the ambient temperature data; The current correction module is used to divide the monitoring time period into different sub-time periods based on the fluctuation of the current data; according to the difference between the fluctuation degree of the current data in each sub-time period and the fluctuation degree of the theoretical corona current value, the current data in each sub-time period is corrected to obtain the effective current data at each moment in each sub-time period; The lightning arrester monitoring module is used to obtain the current abnormal value at each moment in the monitoring time period according to the correlation between the theoretical corona current value and the current effective data at each moment in the monitoring time period and all moments in the previous time period; based on the current abnormal value at the current moment and its adjacent moments, the operating status of the lightning arrester is monitored.

[0005] Furthermore, the step of obtaining the theoretical corona current value at each moment in the monitoring time period includes: According to the difference between the field strength data at each moment in the monitoring period and the field strength data of the lightning drive in the historical period without thundercloud weather, as well as the change trend of the field strength data at each moment, the field strength analysis value at each moment in the monitoring period is obtained; According to the ambient air pressure data and ambient temperature data at each moment in the monitoring time period, the particle kinetic energy value at each moment in the monitoring time period is obtained; According to the field intensity analysis value and the particle kinetic energy value, the theoretical corona current value at each moment in the monitoring time period is obtained; the field intensity analysis value and the particle kinetic energy value are both positively correlated with the theoretical corona current value.

[0006] Furthermore, obtaining the field strength analysis value at each moment in the monitoring time period includes: A two-dimensional coordinate system is established with time as the horizontal axis and field strength data as the vertical axis; the field strength data at all times within the monitoring time period are marked in the two-dimensional coordinate system to obtain coordinate points corresponding to the field strength data; curve fitting is performed on the coordinate points in the two-dimensional coordinate system to obtain a field strength curve; Obtaining the slope of the corresponding coordinate point on the field strength curve at all times during the monitoring period, normalizing the slope to obtain a standard slope; recording the ratio of the standard slope at each time during the monitoring period to the average of the standard slope at all times as the field strength rise rate at each time during the monitoring period; The average value of the field strength data of the lightning drive at all times in the historical period without thundercloud weather is recorded as the field strength reference value; According to the difference between the field strength data at each moment in the monitoring time period and the field strength reference value, as well as the field strength rising rate, the field strength analysis value at each moment in the monitoring time period is obtained; the difference between the field strength data at each moment and the field strength reference value and the field strength rising rate are both positively correlated with the field strength analysis value.

[0007] Furthermore, the method for acquiring the effective current data at each moment in each sub-time period includes: Obtain the fluctuation index of the current data at all times in each sub-time period, recorded as the current fluctuation value; obtain the fluctuation index of the theoretical corona current value at all times in each sub-time period, recorded as the current theoretical fluctuation value; The current fluctuation value and the theoretical current fluctuation value are respectively standardized to obtain a current fluctuation standard value and a current theoretical fluctuation standard value; the absolute value of the difference between the current fluctuation standard value and the theoretical current fluctuation standard value in each sub-time period is negatively correlated and normalized to obtain a current adjustment coefficient in each sub-time period; The product of the current adjustment coefficient and the current data at each moment in each sub-time period is used as the current effective data at each moment in each sub-time period.

[0008] Furthermore, obtaining the abnormal current value at each moment in the monitoring time period includes: The time period between the start time of the monitoring time period and each moment is recorded as the analysis time period of each moment, and the time period between the start time of the monitoring time period and the previous moment of each moment is recorded as the reference time period of each moment; The current data of all moments in the analysis time period at each moment in the monitoring time period are arranged in time sequence to obtain a monitoring current sequence at each moment, and the theoretical corona current values ​​of all moments in the analysis time period are arranged in time sequence to obtain a theoretical current sequence at each moment; The current data of all moments in the reference time period at each moment in the monitoring time period are arranged in time sequence to obtain a reference current sequence at each moment, and the theoretical corona current values ​​of all moments in the reference time period are arranged in time sequence to obtain a reference theoretical sequence at each moment; Respectively obtain the correlation coefficient between the monitoring current sequence and the theoretical current sequence and record it as a first correlation value, and obtain the correlation coefficient between the reference current sequence and the reference theoretical sequence and record it as a second correlation value; The difference between the second correlation value and the first correlation value is normalized to obtain the current abnormal value at each moment in the monitoring time period.

[0009] Furthermore, the monitoring of the operating state of the lightning arrester based on the abnormal current value at the current moment and the adjacent moments includes: Record the preset number of adjacent elements before the current moment as the adjacent moments of the current moment; A two-dimensional coordinate system is established with time as the horizontal axis and the current abnormal value as the vertical axis; the current abnormal values ​​at the current moment and the adjacent moments are marked in the two-dimensional coordinate system to obtain the coordinate points of the corresponding current abnormal values; a straight line is fitted to the coordinate points in the two-dimensional coordinate system, and the slope of the fitted straight line is recorded as the abnormal change rate; Record the average of the current abnormal values ​​at the current moment and its adjacent moments as the overall abnormal value at the current moment; According to the abnormal change rate and the overall abnormal value, a normal current index at the current moment is obtained; and based on the normal current index, the operating state of the lightning arrester is monitored.

[0010] Furthermore, the monitoring time period is divided into different sub-time periods based on the fluctuation of the current data, including: A two-dimensional coordinate system is established with time as the horizontal axis and current data as the vertical axis; the current data at all times within the monitoring time period are marked in the two-dimensional coordinate system to obtain coordinate points of the corresponding current data; the coordinate points in the two-dimensional coordinate system are clustered to obtain different clusters; The intervals between the corresponding moments of the coordinate points in each cluster are obtained, and the time period between the two moments corresponding to the maximum value of the interval is recorded as a sub-time period.

[0011] Furthermore, the obtaining of the particle kinetic energy value at each moment in the monitoring time period includes: Standardizing the ambient air pressure data and the ambient temperature data to obtain standard air pressure data and standard temperature data; The product of the standard air pressure data and the standard temperature data at each moment in the monitoring period is normalized to obtain the particle kinetic energy value at the corresponding moment.

[0012] Furthermore, the volatility indicator is standard deviation.

[0013] A lightning protection device for electric power facilities, the device comprising a processor, and the processor, when executed, implements the corona current monitoring system for the lightning protection device for electric power facilities as described above.

[0014] The present invention has the following beneficial effects: In the embodiment of the present invention, the difference between the field strength data at each moment and the field strength data of the lightning drive in the historical time period without thundercloud weather, as well as the changing trend of the field strength data, all reflect the strength of the cloud-to-ground electric field, which affects the degree of particle ionization. The air pressure and temperature affect the ionization level of the positive charge ionized at the tip of the lightning drive. The degree of particle ionization affects the corona current of the lightning drive. The theoretical corona current value is obtained by combining the above factors. The reasons for the fluctuation of the corona current include: insufficient instrument acquisition accuracy and the fluctuation of the corona current itself. Since the actual corona current generated during the operation of the lightning drive is similar to the fluctuation of the current collected by the device, the current value in the sub-time period is The difference between the fluctuation degree of the current data and the fluctuation degree of the theoretical corona current value shows the abnormal degree of the current data in the sub-time period, so as to correct the current data to obtain the effective current data, improve the reliability of the monitoring of the corona current generated by the lightning drive, and solve the problem of the error between the current data obtained by the corona current acquisition device and the actual corona current; then, analyze the correlation between the corrected effective current data and the theoretical corona current value at each moment and the previous moment, effectively improve the accuracy of the abnormal analysis of the current data, and obtain the abnormal current value; finally, monitor the operating status of the lightning drive based on the abnormal current value at the current moment and its adjacent moments. Compared with the threshold analysis based only on the corona current amplitude, this scheme first corrects the current data in combination with the thundercloud field strength and temperature and pressure changes under thundercloud weather to solve the problem of errors caused by insufficient instrument accuracy, and then analyzes the correlation between the corona current collected by the device and the fluctuation of the actual corona current to obtain a more accurate current abnormality index, thereby improving the accuracy of monitoring the operating status of the passive corona field lightning drive. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A system structure diagram of a corona current monitoring system for lightning protection equipment of electric power facilities provided by one embodiment of the present invention; Figure 2 A system structure diagram of a method for obtaining a theoretical corona current value provided by an embodiment of the present invention; Figure 3 A partial schematic diagram of a field strength curve provided by an embodiment of the present invention; Figure 4 A partial schematic diagram of a current data coordinate system provided by an embodiment of the present invention; Figure 5A partial schematic diagram of a current abnormal value coordinate system provided by an embodiment of the present invention; Figure 6 A schematic diagram of a computer device of a lightning protection device for electric power facilities provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation, structure, features and effects of a lightning protection device for power facilities and a corona current monitoring system thereof proposed by the present invention in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0018] Unless defined otherwise, 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 invention belongs.

[0019] The specific scheme of a lightning protection device for electric power facilities and a corona current monitoring system thereof provided by the present invention is described in detail below with reference to the accompanying drawings.

[0020] Embodiment 1: See also Figure 1 , which shows a system block diagram of a corona current monitoring system for lightning protection equipment of power facilities provided by an embodiment of the present invention, the system includes: a data acquisition module 110, a theoretical corona current analysis module 120, a current correction module 130, and a lightning drive monitoring module 140.

[0021] The data acquisition module 110 is used to obtain the field strength data, current data, ambient air pressure data and ambient temperature data of the lightning drive at each moment in the monitoring time period under thundercloud weather; the last moment in the monitoring time period is the current moment.

[0022] Specifically, the field strength data is collected by the field strength meter arranged within the protection range of the passive corona field lightning drive, and the current data of the lightning drive during operation is collected by the arrester current tester or the online current monitoring counter in the lightning drive system; in thundercloud weather, the field strength data and current data of the passive corona field lightning drive at each moment in the monitoring time period are obtained, and the ambient air pressure data at each moment is collected by the vacuum barometer, and the ambient temperature data at each moment is collected by the temperature tester. The last moment in the monitoring time period is the current moment.

[0023] In order to ensure the accuracy of subsequent analysis, each type of data at all times during the monitoring period was denoised, and the denoised data were used for analysis in subsequent steps.

[0024] It should be noted that the duration of the monitoring period is 1 hour, and the sampling frequencies of the field strength data, current data, ambient air pressure data and temperature data are the same, and the sampling frequencies of the four data are all once per second, which can be set by the implementer according to the specific situation. This embodiment uses the mean filtering algorithm for denoising, which is a well-known technology and will not be described in detail here.

[0025] The theoretical corona current analysis module 120 is used to obtain the theoretical corona current value at each moment in the monitoring time period based on the difference between the field strength data at each moment in the monitoring time period and the field strength data of the lightning drive in thundercloud-free weather in the historical time period, as well as the changing trend of the field strength data at each moment, the ambient air pressure data and the ambient temperature data.

[0026] The difference between the field strength data at each moment and the field strength data of the lightning drive in the historical period without thundercloud weather, as well as the changing trend of the field strength data, comprehensively reflect the strength of the cloud-to-ground electric field. The electric field strength affects the speed of particles in the air, thereby affecting the degree of particle ionization; air pressure and temperature affect the kinetic energy of gas particles, the probability of particle collision in the cloud-to-ground electric field, and then affect the degree of particle ionization, and the degree of particle ionization directly affects the strength of the corona current generated by the lightning drive. Therefore, the theoretical corona current value is obtained by combining the above factors, that is, the corona current actually generated by the lightning drive.

[0027] See also Figure 2 , which shows a system structure diagram of a method for obtaining a theoretical corona current value provided by an embodiment of the present invention. The system includes: a field strength analysis unit 121, a kinetic energy analysis unit 122, and a theoretical current analysis unit 123.

[0028] Field strength analysis unit 121: obtains the field strength analysis value at each moment in the monitoring time period according to the difference between the field strength data at each moment in the monitoring time period and the field strength data of the lightning drive in thundercloud-free weather in the historical time period, as well as the change trend of the field strength data at each moment.

[0029] The field strength data at all times in the historical time period without thundercloud weather are collected through the field strength meter arranged within the protection range of the passive corona field lightning repellent. It should be noted that the end time of the historical time period is the start time of the monitoring time period, and the duration of the historical time period is an empirical value of 30 days, which can be set by the implementer according to the specific situation.

[0030] Thundercloud weather can cause the electric field intensity between clouds and the ground to rise rapidly. The faster the electric field intensity between clouds and the ground rises and the greater the difference between the electric field intensity in thundercloud weather and that in non-thundercloud weather, the more obvious the tip discharge effect of the passive corona field lightning drive will be, the greater the corona current generated by the lightning drive will be, and the greater the intensity of the electric field between clouds and the ground will be.

[0031] Preferably, in some possible implementation modes of the embodiments of the present invention, the method for obtaining the field strength analysis value includes: establishing a two-dimensional coordinate system with time as the horizontal axis and field strength data as the vertical axis; marking the field strength data at all times in the monitoring time period in the two-dimensional coordinate system to obtain the coordinate points of the corresponding field strength data; performing curve fitting on the coordinate points in the two-dimensional coordinate system to obtain a field strength curve; obtaining the slope of the corresponding coordinate points on the field strength curve at all times in the monitoring time period, and normalizing the slope to obtain a standard slope; recording the ratio of the standard slope at each time in the monitoring time period to the average of the standard slopes at all times as the field strength rise rate at each time in the monitoring time period; recording the average of the field strength data of the lightning drive at all times in thundercloud-free weather in the historical time period as the field strength reference value; obtaining the field strength analysis value at each time in the monitoring time period based on the difference between the field strength data at each time in the monitoring time period and the field strength reference value, as well as the field strength rise rate.

[0032] Figure 3 A partial schematic diagram of a field strength curve provided by an embodiment of the present invention is shown in FIG. Figure 3 As shown, Figure 3 The horizontal axis t of the coordinate system represents time in seconds, and the vertical axis E represents the field strength in Newtons per coulomb; each point represents the coordinate point of the field strength data at each moment. Figure 3 The curve in is a field strength curve. In order to avoid the slope being negative and affecting the analysis of the field strength analysis value, the slope is normalized. In the embodiment of the present invention, the range normalization method is used for normalization. In other embodiments of the present invention, the Z score normalization method and the decimal calibration normalization method can also be used.

[0033] The slope of the coordinate point on the field strength curve shows the change trend of the cloud-to-ground field strength at each moment in the monitoring period, and the mean of the standard slopes at all moments in the monitoring period reflects the overall change trend of the cloud-to-ground field strength during the monitoring period; if the field strength rise rate is greater, the change trend of the cloud-to-ground field strength at each moment should be greater than the overall change trend of the cloud-to-ground field strength during the monitoring period, and the electric field strength between the cloud and the ground at each moment rises faster. The field strength reference value reflects the standard level of the cloud-to-ground field strength of the lightning drive in thundercloud-free weather. If the difference between the field strength data at each moment and the field strength reference value is greater, and the field strength rise rate is greater, it indicates that the difference between the electric field strength at each moment in thundercloud weather and the electric field strength in non-thundercloud weather is greater, and the faster the intensity of the cloud-to-ground electric field at each moment rises, the more obvious the tip discharge effect of the passive corona field lightning drive is, the greater the corona current generated by the lightning drive at each moment, the greater the intensity of the cloud-to-ground electric field, and the greater the field strength analysis value.

[0034] Therefore, the difference between the field intensity data at each moment and the field intensity reference value and the field intensity rise rate are both positively correlated with the field intensity analysis value. In the embodiment of the present invention, the product of the absolute value of the difference between the field intensity data at each moment and the field intensity reference value and the field intensity rise rate is normalized to obtain the field intensity analysis value at each moment in the monitoring time period. In the embodiment of the present invention, the difference between the field intensity data at each moment and the field intensity reference value and the correlation between the field intensity rise rate and the field intensity analysis value can also be constructed by other basic mathematical operations, which will not be limited or elaborated herein.

[0035] It should be noted that in the embodiment of the present invention, the Norm function is used for normalization processing. In other embodiments, other normalization methods may be selected, such as function conversion, maximum and minimum normalization, etc., which are not limited here. The embodiment of the present invention uses the least squares method to perform curve fitting on the coordinate points in the two-dimensional coordinate system. Among them, the least squares method is a well-known technology for those skilled in the art and will not be described in detail here.

[0036] Kinetic energy analysis unit 122: obtains the particle kinetic energy value at each moment in the monitoring time period according to the ambient air pressure data and ambient temperature data at each moment in the monitoring time period.

[0037] The increase in air pressure and temperature will increase the kinetic energy of gas particles. Therefore, the ambient air pressure data and ambient temperature data are analyzed comprehensively to obtain the particle kinetic energy value.

[0038] Preferably, in some possible implementation modes of the embodiments of the present invention, the method for obtaining the particle kinetic energy value includes: standardizing the ambient air pressure data and the ambient temperature data respectively to obtain standard air pressure data and standard temperature data; normalizing the product of the standard air pressure data and the standard temperature data at each moment in the monitoring time period to obtain the particle kinetic energy value at the corresponding moment.

[0039] Since the dimensions of the ambient air pressure data and the ambient temperature data are different, the ambient air pressure data and the ambient temperature data need to be standardized before analysis. The embodiment of the present invention selects the range standardization method for standardization and uses the Norm function for normalization.

[0040] Theoretical current analysis unit 123: obtains the theoretical corona current value at each moment in the monitoring time period according to the field strength analysis value and the particle kinetic energy value; the field strength analysis value and the particle kinetic energy value are both positively correlated with the theoretical corona current value.

[0041] If the field strength analysis value is larger, the intensity of the cloud-to-ground electric field is larger, the particle acceleration speed is faster, the kinetic energy is higher, and the particles are more likely to collide and ionize the surrounding air molecules, the particle ionization degree is greater; if the particle kinetic energy value is larger, the gas particle kinetic energy is more intense, resulting in a greater probability of particle collision in the cloud-to-ground electric field, the greater the possibility of particle ionization, and the greater the particle ionization degree; the greater the particle ionization degree, the higher the concentration of free electrons and ions in the air, the stronger the corona current generated by the lightning repellent, and the increased conductivity of the cloud-to-ground electric field. Therefore, the field strength analysis value and the particle kinetic energy value are positively correlated with the theoretical corona current value. The theoretical corona current value is the current data that is not affected by the acquisition accuracy of the device.

[0042] In the embodiment of the present invention, the product of the field strength analysis value and the particle kinetic energy value at each moment in the monitoring time period is used as the theoretical corona current value at the corresponding moment. In the embodiment of the present invention, the correlation between the field strength analysis value, the particle kinetic energy value and the theoretical corona current value can also be constructed by other basic mathematical operations, which will not be limited or elaborated herein.

[0043] The current correction module 130 is used to divide the monitoring time period into different sub-time periods based on the fluctuation of the current data; according to the difference between the fluctuation degree of the current data in each sub-time period and the fluctuation degree of the theoretical corona current value, the current data in each sub-time period is corrected to obtain the effective current data at each moment in each sub-time period.

[0044] Complex thundercloud weather can easily reduce the collection accuracy of the corona current collection device. The corona current appears as a local burr-like signal with strong fluctuations. In order to ensure the accuracy of the analysis, it is necessary to correct the local burr-like signal caused by the instrument collection accuracy.

[0045] Firstly, in order to improve the accuracy of corona current correction, the monitoring time period is divided into different sub-time periods.

[0046] In an embodiment of the present invention, the method for dividing sub-time periods is as follows: a two-dimensional coordinate system is established with time as the horizontal axis and current data as the vertical axis; the current data at all times within the monitoring time period are marked in the two-dimensional coordinate system to obtain the coordinate points of the corresponding current data; the coordinate points in the two-dimensional coordinate system are clustered to obtain different clustering clusters; the intervals between the corresponding moments of the coordinate points in each clustering cluster are obtained, and the time period between the two moments corresponding to the maximum value of the interval is recorded as a sub-time period. Figure 4 A partial schematic diagram of a current data coordinate system provided by an embodiment of the present invention, such as Figure 4 As shown, Figure 4 The horizontal axis t of the current data coordinate system represents time in seconds, and the vertical axis I represents current data in amperes. Figure 4Each point in represents the coordinate point of the current data at each moment. Since the field strength and current may have a certain correlation in some cases, Figure 3 and Figure 4 The points in the middle have the same changing trend.

[0047] It should be noted that, in the embodiment of the present invention, the K-means clustering algorithm is selected to cluster the coordinate points in the two-dimensional coordinate system, and the K value is determined by the elbow method. Among them, the K-means clustering algorithm and the elbow method are both well-known technologies for those skilled in the art, and will not be described in detail here.

[0048] The fluctuation of corona current may be caused by the insufficient collection accuracy of the corona current collection device, or it may be the abnormal fluctuation of the corona current itself. Because the current data is the corona current collected by the corona current collection device, the theoretical corona current value is the corona current actually generated by the lightning arrester, and the error caused by the insufficient collection accuracy of the collection device accounts for a small part of the data, so the current data generated during the operation of the lightning arrester is similar to the fluctuation of the theoretical corona current value.

[0049] Therefore, the abnormality of the current data in the sub-time period can be analyzed through the difference between the fluctuation degree of the current data in the sub-time period and the fluctuation degree of the theoretical corona current value, and then the current data can be corrected to obtain the effective current data.

[0050] Preferably, in some possible implementation modes of the embodiments of the present invention, the method for obtaining effective current data includes: obtaining a fluctuation index of the current data at all times in each sub-time period, recorded as a current fluctuation value; obtaining a fluctuation index of the theoretical corona current value at all times in each sub-time period, recorded as a theoretical current fluctuation value; standardizing the current fluctuation value and the theoretical current fluctuation value, respectively, to obtain a current fluctuation standard value and a current theoretical fluctuation standard value; negatively correlating and normalizing the absolute value of the difference between the current fluctuation standard value and the theoretical current fluctuation standard value of each sub-time period to obtain a current adjustment coefficient for each sub-time period; and taking the product of the current adjustment coefficient and the current data at each time in each sub-time period as the effective current data at each time in each sub-time period.

[0051] The fluctuation index reflects the degree of fluctuation of a set of data. Indicators such as standard deviation, variance and range can all reflect the degree of fluctuation of a set of data. In the embodiment of the present invention, the fluctuation index is the standard deviation, that is, the standard deviation of the current data at all times in each sub-time period is recorded as the current fluctuation value, and the current theoretical fluctuation value is obtained in the same way as the current fluctuation value. In other embodiments, variance and range can also be used as fluctuation indicators. In this embodiment, the current fluctuation value is standardized by the ratio of the current fluctuation value of each sub-time period to the maximum value of the current fluctuation values ​​of all sub-time periods in the monitoring time period; the standardization method of the theoretical current fluctuation value is the same.

[0052] If the fluctuation of the current data in the sub-time period is more similar to that of the theoretical corona current value, the fluctuation of the current data in the sub-time period is more likely to be the normal fluctuation of the corona current itself; if the difference in the fluctuation degree of the current data in the sub-time period is greater than that of the theoretical corona current value, the fluctuation of the current data in the sub-time period is more likely to be the abnormal fluctuation caused by the insufficient accuracy of the corona current collection device.

[0053] The absolute value of the difference between the current fluctuation value in a sub-time period and the theoretical current fluctuation value reflects the similarity between the fluctuation degree of the current data in the sub-time period and the theoretical corona current value; the abnormal fluctuation of the corona current is manifested as a local burr-like signal, that is, the current data at the abnormal fluctuation position of the corona current is greater than the actual current value. When the absolute value of the above difference is larger, the fluctuation of the current data in the sub-time period is more likely to be an abnormal fluctuation. The current data in the sub-time period is much larger than the actual current value, and the current data in the sub-time period needs to be reduced to a greater extent, and the current adjustment coefficient is smaller. Therefore, the absolute value of the difference between the current fluctuation standard value of the sub-time period and the current theoretical fluctuation standard value is negatively correlated and normalized to obtain the current adjustment coefficient.

[0054] It should be noted that this embodiment uses an exponential function with natural constants as the base for negative correlation and normalization processing. The specific operation is: first take the negative value of the absolute value of the difference between the current fluctuation standard value of the sub-time period and the current theoretical fluctuation standard value, and use the negative number as the exponent of the exponential function with natural constants as the base, thereby achieving negative correlation and normalization processing.

[0055] When the current adjustment coefficient is closer to the constant 0, the fluctuation of the current data in the sub-time period is more likely to be caused by the insufficient accuracy of the corona current acquisition device, and the current data in the sub-time period needs to be adjusted to a greater extent, that is, the current data at the position where the corona current fluctuates abnormally is much larger than the actual current value. The smaller the effective current data obtained by multiplying the current adjustment coefficient by the current data at each moment in the sub-time period, the closer it is to the actual current value, thereby realizing the correction of the current data in the monitoring time period.

[0056] By analyzing the correlation between the fluctuation characteristics of the corona current obtained by the acquisition device and the theoretical corona current fluctuation, it is inferred whether the fluctuation is caused by the change of the actual corona current or the error caused by the instrument accuracy, so as to correct the current data at the fluctuation position and effectively improve the reliability of monitoring the corona current generated by the lightning drive.

[0057] The lightning arrester monitoring module 140 is used to obtain the current abnormality value at each moment in the monitoring time period according to the correlation between the theoretical corona current value and the current effective data at each moment in the monitoring time period and all moments in the previous time period; based on the current abnormality value at the current moment and its adjacent moments, the operating status of the lightning arrester is monitored.

[0058] By analyzing the correlation between the corrected current effective data and the theoretical corona current value at each moment and the previous moment, the accuracy of abnormal analysis of current data is effectively improved, and the current abnormal value is obtained.

[0059] Preferably, in some possible implementation modes of the embodiments of the present invention, the method for obtaining the current abnormal value includes: recording the time period between the start time of the monitoring time period and each moment as the analysis time period of each moment, and recording the time period between the start time of the monitoring time period and the adjacent previous moment of each moment as the reference time period of each moment; arranging the current data of all moments in the analysis time period of each moment in the monitoring time period in time series to obtain the monitoring current sequence of each moment, and arranging the theoretical corona current values ​​of all moments in the analysis time period in time series to obtain the theoretical current sequence of each moment; arranging the current data of all moments in the reference time period of each moment in the monitoring time period in time series to obtain the reference current sequence of each moment, and arranging the theoretical corona current values ​​of all moments in the reference time period in time series to obtain the reference theoretical sequence of each moment; obtaining the correlation coefficient between the monitoring current sequence and the theoretical current sequence as the first correlation value, and obtaining the correlation coefficient between the reference current sequence and the reference theoretical sequence as the second correlation value; normalizing the difference between the second correlation value and the first correlation value to obtain the current abnormal value of each moment in the monitoring time period.

[0060] Any moment in the monitoring time period is recorded as the target moment. The difference between the analysis time period and the reference time period of the target moment is that the analysis time period includes the target moment, while the reference time period does not include the target moment. If the correlation between the effective current data and the theoretical corona current value in the reference time period of the target moment is better, but the correlation between the effective current data and the theoretical corona current value in the analysis time period including the target moment is lower, it means that the current data at the target moment and the theoretical corona current value destroy the correlation between the effective current data and the theoretical corona current value in the reference time period more seriously, and the abnormality of the corona current at the target moment is greater.

[0061] The correlation coefficient between the monitoring current sequence and the theoretical current sequence at the target time reflects the similarity between the fluctuation of the effective current data and the theoretical corona current value in the analysis time period at the target time. If the difference between the second correlation value and the first correlation value is larger, it means that compared with the reference time period at the target time, the similarity between the fluctuation of the effective current data and the theoretical corona current value in the monitoring time period after the target time is worse, and the abnormality of the corona current at the target time is greater, and the current abnormality value is greater.

[0062] In the embodiment of the present invention, the correlation coefficient is the Pearson correlation coefficient, and the Norm function is used for normalization. In other embodiments of the present invention, the correlation coefficient may also be the Spearman correlation coefficient, the Kendall rank correlation coefficient, the canonical correlation coefficient, etc., and normalization methods such as function conversion may also be used.

[0063] By analyzing the abnormal current values ​​at the current moment and its adjacent moments, the normal current index at the current moment is determined, and then the operating status of the lightning arrester is monitored.

[0064] Preferably, in some possible implementation modes of the embodiments of the present invention, the method for obtaining the normal current index includes: recording a preset number of adjacent elements before the current moment as adjacent moments of the current moment; establishing a two-dimensional coordinate system with time as the horizontal axis and the current abnormal value as the vertical axis; marking the current abnormal values ​​of the current moment and its adjacent moments in the two-dimensional coordinate system to obtain the coordinate points of the corresponding current abnormal values; performing straight line fitting on the coordinate points in the two-dimensional coordinate system, and recording the slope of the fitted straight line as the abnormal change rate; recording the average of the current abnormal values ​​of the current moment and its adjacent moments as the overall abnormal value of the current moment; and obtaining the normal current index of the current moment based on the abnormal change rate and the overall abnormal value.

[0065] Figure 5 A partial schematic diagram of a current abnormal value coordinate system provided by an embodiment of the present invention is shown in FIG. Figure 5 As shown, Figure 5 The horizontal axis t of the current anomaly value coordinate system represents time in seconds, and the vertical axis R represents the current anomaly value. Figure 5 Each point in represents the coordinate point of the abnormal current value at each moment; Figure 5 The slope of the middle straight line is the abnormal change rate. Since the current abnormal value is obtained based on the Pearson correlation coefficient, the current abnormal value has no unit. The abnormal change rate reflects the changing trend of the current abnormal value at the current moment and its adjacent moments. If the abnormal change rate is larger, it means that the growth rate of the current abnormal value at the current moment and its adjacent moments is faster, and the abnormal degree of the corona current at the current moment is greater. The overall abnormal value reflects the overall abnormal level of the corona current at the current moment and its adjacent moments. If the overall abnormal value is larger, it means that the overall abnormal level of the corona current at the current moment and its adjacent moments is larger, and the abnormal degree of the corona current at each moment is greater. Therefore, the abnormal change rate and the overall abnormal value are negatively correlated with the normal current index. In an embodiment of the present invention, the product of the abnormal change rate at the current moment and the overall abnormal value is negatively correlated and normalized to obtain the normal current index at the current moment.

[0066] It should be noted that in the embodiment of the invention, the preset number is an empirical value of 10, and the implementer can set it according to the specific situation; the least square method is used to perform straight line fitting on the coordinate points in the two-dimensional coordinate system. Among them, the least square method is a well-known technology for those skilled in the art and will not be described in detail here.

[0067] In a specific implementation of the embodiment of the present invention, the current normality index is expressed by a formula: In the formula, IL is the normal current index at the current moment; K is the abnormal change rate at the current moment; is the overall abnormal value at the current moment; exp is an exponential function with a natural constant as the base. The value range of the normal current index is .

[0068] If the normal current index at the current moment is larger, it means that the corona current at the current moment is more normal, and the operating state of the lightning arrester at the current moment is more normal.

[0069] Based on the normal current index, the operating state of the lightning arrester is monitored. This embodiment specifically includes: if the normal current index at the current moment is , then the passive corona field lightning drive is operating normally; if the current normal index at the current moment is , then the natural thundercloud electric field is not effective enough to drive the passive corona field lightning driver, and an external electric field needs to be applied to the passive corona field lightning driver until the normal current index is greater than a; if the normal current index at the current moment is , then the passive corona field lightning arrester is faulty and in an abnormal operating state, and the lightning arrester needs to be replaced under safe conditions. Wherein, a is the first preset value, and b is the second preset value.

[0070] It should be noted that in the embodiment of the present invention, the first preset value a is an empirical value of 0.7, and the second preset value b is an empirical value of 0.3. The implementer can set the first preset value and the second preset value according to the specific situation.

[0071] So far, the present invention is completed.

[0072] Embodiment 2: Figure 6 A schematic diagram of a computer device for a lightning protection device for electric power facilities provided by an embodiment of the present invention. For example, Figure 6 As shown, the computer device includes: a memory 201, a processor 202, and a computer program 203 stored in the memory 201 and running on the processor 202, wherein when the processor 202 executes the computer program 203, the computer device can execute any one of the corona current monitoring systems for lightning protection equipment of power facilities introduced above.

[0073] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to execute a corona current monitoring system for a lightning protection device for an electric power facility provided in an embodiment of the present application.

[0074] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0075] It should be understood that the device provided in this embodiment is used to implement the above-mentioned corona current monitoring system for lightning protection equipment of power facilities, and thus can achieve the same effect as the above-mentioned implementation method.

[0076] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a device, the processing module may be used to control and manage the actions of the device. The storage module may be used to support the device to execute mutual program codes, etc.

[0077] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits disclosed in the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0078] Embodiment 3: This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is executed on a computer, the computer executes the above-mentioned related method steps to implement a corona current monitoring system for a lightning protection device for an electric power facility provided in the above embodiment.

[0079] Among them, the device and computer-readable storage medium provided in this embodiment are used to execute the corresponding system provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding system provided above, and will not be repeated here.

[0080] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0081] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A corona current monitoring system for lightning protection equipment of power facilities, characterized in that: The system includes: The data acquisition module is used to obtain the field strength data, current data, ambient air pressure data and ambient temperature data of the lightning drive at each moment in the monitoring time period under thundercloud weather; the last moment in the monitoring time period is the current moment; Theoretical corona current analysis module is used to obtain the theoretical corona current value at each moment in the monitoring period according to the difference between the field strength data at each moment in the monitoring period and the field strength data of the lightning drive in the historical period without thundercloud weather, as well as the change trend of the field strength data at each moment, the ambient air pressure data and the ambient temperature data; The current correction module is used to divide the monitoring time period into different sub-time periods based on the fluctuation of the current data; according to the difference between the fluctuation degree of the current data in each sub-time period and the fluctuation degree of the theoretical corona current value, the current data in each sub-time period is corrected to obtain the effective current data at each moment in each sub-time period; The lightning arrester monitoring module is used to obtain the current abnormal value at each moment in the monitoring time period according to the correlation between the theoretical corona current value and the current effective data at each moment in the monitoring time period and all moments in the previous time period; based on the current abnormal value at the current moment and its adjacent moments, the operating status of the lightning arrester is monitored.

2. A corona current monitoring system for lightning protection equipment of electric power facilities according to claim 1, characterized in that: The step of obtaining the theoretical corona current value at each moment in the monitoring time period includes: According to the difference between the field strength data at each moment in the monitoring period and the field strength data of the lightning drive in the historical period without thundercloud weather, as well as the change trend of the field strength data at each moment, the field strength analysis value at each moment in the monitoring period is obtained; According to the ambient air pressure data and ambient temperature data at each moment in the monitoring time period, the particle kinetic energy value at each moment in the monitoring time period is obtained; According to the field intensity analysis value and the particle kinetic energy value, the theoretical corona current value at each moment in the monitoring time period is obtained; the field intensity analysis value and the particle kinetic energy value are both positively correlated with the theoretical corona current value.

3. A corona current monitoring system for lightning protection equipment of electric power facilities according to claim 2, characterized in that: The obtaining of the field strength analysis value at each moment in the monitoring time period includes: A two-dimensional coordinate system is established with time as the horizontal axis and field strength data as the vertical axis; the field strength data at all times within the monitoring time period are marked in the two-dimensional coordinate system to obtain coordinate points corresponding to the field strength data; curve fitting is performed on the coordinate points in the two-dimensional coordinate system to obtain a field strength curve; Obtaining the slope of the corresponding coordinate point on the field strength curve at all times during the monitoring period, normalizing the slope to obtain a standard slope; recording the ratio of the standard slope at each time during the monitoring period to the average of the standard slope at all times as the field strength rise rate at each time during the monitoring period; The average value of the field strength data of the lightning drive at all times in the historical period without thundercloud weather is recorded as the field strength reference value; According to the difference between the field strength data at each moment in the monitoring time period and the field strength reference value, as well as the field strength rising rate, the field strength analysis value at each moment in the monitoring time period is obtained; the difference between the field strength data at each moment and the field strength reference value and the field strength rising rate are both positively correlated with the field strength analysis value.

4. The corona current monitoring system for lightning protection equipment of electric power facilities according to claim 1, characterized in that: The method for acquiring the effective current data at each moment in each sub-time period includes: Obtain the fluctuation index of the current data at all times in each sub-time period, recorded as the current fluctuation value; obtain the fluctuation index of the theoretical corona current value at all times in each sub-time period, recorded as the current theoretical fluctuation value; The current fluctuation value and the theoretical current fluctuation value are respectively standardized to obtain a current fluctuation standard value and a current theoretical fluctuation standard value; the absolute value of the difference between the current fluctuation standard value and the theoretical current fluctuation standard value in each sub-time period is negatively correlated and normalized to obtain a current adjustment coefficient in each sub-time period; The product of the current adjustment coefficient and the current data at each moment in each sub-time period is used as the current effective data at each moment in each sub-time period.

5. The corona current monitoring system for lightning protection equipment of electric power facilities according to claim 1, characterized in that: The obtaining of the abnormal current value at each moment in the monitoring time period includes: The time period between the start time of the monitoring time period and each moment is recorded as the analysis time period of each moment, and the time period between the start time of the monitoring time period and the previous moment of each moment is recorded as the reference time period of each moment; The current data of all moments in the analysis time period at each moment in the monitoring time period are arranged in time sequence to obtain a monitoring current sequence at each moment, and the theoretical corona current values ​​of all moments in the analysis time period are arranged in time sequence to obtain a theoretical current sequence at each moment; The current data of all moments in the reference time period at each moment in the monitoring time period are arranged in time sequence to obtain a reference current sequence at each moment, and the theoretical corona current values ​​of all moments in the reference time period are arranged in time sequence to obtain a reference theoretical sequence at each moment; Respectively obtain the correlation coefficient between the monitoring current sequence and the theoretical current sequence and record it as a first correlation value, and obtain the correlation coefficient between the reference current sequence and the reference theoretical sequence and record it as a second correlation value; The difference between the second correlation value and the first correlation value is normalized to obtain the current abnormal value at each moment in the monitoring time period.

6. The corona current monitoring system for lightning protection equipment of electric power facilities according to claim 1, characterized in that: The monitoring of the operating state of the lightning arrester based on the abnormal current value at the current moment and the adjacent moments includes: Record the preset number of adjacent elements before the current moment as the adjacent moments of the current moment; A two-dimensional coordinate system is established with time as the horizontal axis and the current abnormal value as the vertical axis; the current abnormal values ​​at the current moment and the adjacent moments are marked in the two-dimensional coordinate system to obtain the coordinate points of the corresponding current abnormal values; a straight line is fitted to the coordinate points in the two-dimensional coordinate system, and the slope of the fitted straight line is recorded as the abnormal change rate; Record the average of the current abnormal values ​​at the current moment and its adjacent moments as the overall abnormal value at the current moment; According to the abnormal change rate and the overall abnormal value, a normal current index at the current moment is obtained; and based on the normal current index, the operating state of the lightning arrester is monitored.

7. A corona current monitoring system for lightning protection equipment of electric power facilities according to claim 1, characterized in that: The monitoring time period is divided into different sub-time periods based on the fluctuation of the current data, including: A two-dimensional coordinate system is established with time as the horizontal axis and current data as the vertical axis; the current data at all times within the monitoring time period are marked in the two-dimensional coordinate system to obtain coordinate points of the corresponding current data; the coordinate points in the two-dimensional coordinate system are clustered to obtain different clusters; The intervals between the corresponding moments of the coordinate points in each cluster are obtained, and the time period between the two moments corresponding to the maximum value of the interval is recorded as a sub-time period.

8. A corona current monitoring system for lightning protection equipment of electric power facilities according to claim 2, characterized in that: The step of obtaining the particle kinetic energy value at each moment in the monitoring time period includes: Standardizing the ambient air pressure data and the ambient temperature data to obtain standard air pressure data and standard temperature data; The product of the standard air pressure data and the standard temperature data at each moment in the monitoring period is normalized to obtain the particle kinetic energy value at the corresponding moment.

9. A corona current monitoring system for lightning protection equipment of electric power facilities according to claim 4, characterized in that: The volatility indicator is the standard deviation.

10. A lightning protection device for power facilities, characterized in that: The device comprises a processor, and when the processor is executed, a corona current monitoring system for a lightning protection device for electric power facilities according to any one of claims 1 to 9 is implemented.

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