A method for early warning of pollution in transmission line insulators

Abstract

This invention discloses a method for early warning of insulator pollution in transmission lines, relating to the field of online monitoring technology for power transmission networks. The method includes: first, acquiring historical daily current traveling wave data and historical meteorological data of the transmission line; then, calculating the equivalent salt density value along the transmission line on the current day based on the historical daily current traveling wave data and historical meteorological data; and finally, sending an insulator pollution early warning signal if the equivalent salt density value along the transmission line on the current day exceeds a preset equivalent salt density threshold. This invention's insulator pollution early warning method eliminates the need for power outages and on-tower inspections, enabling real-time, online assessment of the pollution accumulation across the entire line, determining the equivalent salt density value of the transmission line, and issuing early warning signals.

Description

Technical Field

[0001] This invention relates to the field of online detection technology for power transmission networks, and in particular to a method for early warning of pollution insulators of power transmission lines. Background Technology

[0002] The external insulation level of transmission lines under polluted conditions has a significant impact on the safe operation of the lines. Pollution on the surface of insulators is one of the main factors affecting the pollution tolerance characteristics of insulators. Due to the impact of pollution on power transmission and transformation equipment, the external insulation level of transmission lines decreases, which in turn leads to frequent flashover accidents on transmission lines, causing huge losses to power production. Therefore, strengthening equipment inspection and defect management of transmission lines is an important measure to improve the operation and management level of transmission lines.

[0003] In existing technologies, power companies obtain information about the pollution levels of transmission line insulators by using the equivalent salt density method, which involves classifying the pollution level based on annual cleaning. However, this method requires power outages or inspections on towers, causing inconvenience and power outage losses. Furthermore, it cannot provide a real-time assessment of the overall pollution level of the line or determine the equivalent salt density value of the transmission line. Summary of the Invention

[0004] This invention provides a method for early warning of pollution insulators of transmission lines, which solves the technical problems of existing methods for calibrating pollution levels requiring power outages or inspections on towers, resulting in inconvenience and power outage losses, and the inability to assess the pollution accumulation of the entire line in real time and to grasp the equivalent salt density value of the transmission line.

[0005] This invention provides a method for early warning of pollution insulators of transmission lines, comprising:

[0006] Acquire historical daily current traveling wave data and historical meteorological data for transmission lines;

[0007] The equivalent salt density value along the transmission line on that day was calculated based on historical daily current traveling wave data and historical meteorological data.

[0008] If the equivalent salt density value along the transmission line on that day exceeds the preset equivalent salt density threshold, an insulator pollution warning signal will be sent.

[0009] In some embodiments, the step of calculating the equivalent salt density value along the transmission line on a given day based on historical daily current traveling wave data and historical meteorological data includes:

[0010] Based on the historical daily current traveling wave data of the transmission line, a table of historical daily discharge results is obtained;

[0011] Calculate the daily discharge probability density at each point along the transmission line based on the historical daily discharge results table;

[0012] The daily distribution of accumulated pollution along the transmission line is calculated based on the daily discharge probability density at various points along the line.

[0013] The equivalent salt density distribution along the transmission line on that day was calculated based on historical meteorological data and the daily distribution of accumulated pollution along the transmission line.

[0014] In some embodiments, calculating the daily discharge probability density at each point along the transmission line based on the historical daily discharge result table includes:

[0015] The daily discharge probability density at each point along the transmission line is calculated using the following formula:

[0016]

[0017] Where x is the distance from each point along the line to the small station, σ is the standard deviation of the empirical positioning error, which is generally taken as 300 meters, and μ is the distance from the discharge point to the small station.

[0018] In some embodiments, the step of calculating the daily pollution distribution along the transmission line based on the daily discharge probability density at various points along the transmission line includes:

[0019] The daily pollution distribution along the transmission line is calculated using the following formula:

[0020]

[0021] Where c(x,y) is the pollution value of a point on the transmission line x meters away from the small station on day y, and n is the number of discharges on day t.

[0022] In some embodiments, the step of calculating the equivalent salt density distribution along the transmission line on a given day based on historical meteorological data and the daily pollution distribution along the transmission line includes:

[0023] The equivalent salt density distribution along the transmission line on that day can be calculated using the following formula:

[0024]

[0025] Where E(x,d) is the equivalent salt density value calibrated on-site at point x on day d, and c(x,d) is the dirt accumulation value of the x-meter of the transmission line on day d when cleaning the transmission line.

[0026] In some embodiments, after calculating the daily discharge probability density at each point along the transmission line based on the historical daily discharge result table, the process includes:

[0027] The daily discharge probability density at each point along the transmission line is corrected based on distance weight and amplitude weight.

[0028] In some embodiments, the step of correcting the daily discharge probability density at each point along the transmission line based on distance weight and amplitude weight includes:

[0029] The daily discharge probability density at each point along the transmission line is corrected according to the following formula:

[0030]

[0031] Among them, d1 and d2 are the distances from the detection equipment on both sides of the discharge point to the small station in the historical daily discharge results table, a is the larger traveling wave amplitude value detected by the detection equipment on both sides of the discharge point in the historical daily discharge results table, and w(x) is the distance weight of the discharge point in the historical daily discharge results table.

[0032] In some embodiments, the step of calculating the equivalent salt density distribution along the transmission line on a given day based on historical meteorological data and the daily distribution of accumulated pollution along the line includes:

[0033] The distribution of accumulated pollution along the route was revised for the first time based on historical meteorological data.

[0034] Based on the most recent insulator cleaning record, the distribution of accumulated dirt along the line on the day of the first correction will be revised a second time.

[0035] The equivalent salt density distribution map along the transmission line on that day was calculated based on the most recent on-site equivalent salt density calibration value at each point of the transmission line and the second revised daily distribution of accumulated pollution along the line.

[0036] In some embodiments, the first correction of the daily pollution distribution along the route based on historical meteorological data includes:

[0037] The first correction to the daily pollution distribution along the route is made based on the following formula:

[0038] c ′ (x,y)| y≥d =c(x,y)| y≥d ·e -kA(x,d) ;

[0039] Where e is the natural constant, k is the insulator material coefficient, and A(x,d) is the meteorological data of the point x meters away from the small station on day d.

[0040] In some embodiments, the second correction of the daily pollution distribution along the line based on the most recent insulator cleaning record includes:

[0041] The daily pollution distribution along the line, which was corrected in the first correction, is then corrected a second time using the following formula:

[0042] c ″ (x,y)|y≥d =max(c ′ (x,y)| y≥d -c(x,d),0);

[0043] Among them, c ′ (x,y) represents the dirt accumulation value of the x-th meter of the transmission line after cleaning the transmission line on day d, and c(x,d) represents the dirt accumulation value of the x-th meter of the transmission line on day d when the transmission line is cleaned.

[0044] The beneficial effects of the technical solution provided by this invention include:

[0045] This invention provides a method for early warning of insulator pollution in transmission lines. First, historical daily current traveling wave data and historical meteorological data of the transmission line are acquired. Then, the equivalent salt density value along the transmission line on that day is calculated based on the historical daily current traveling wave data and historical meteorological data. If the equivalent salt density value along the transmission line on that day exceeds a preset equivalent salt density threshold, an insulator pollution early warning signal is sent. This method eliminates the need for power outages and on-tower inspections, enabling real-time, online assessment of pollution accumulation across the entire line, determining the equivalent salt density value of the transmission line, and issuing early warning signals. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is an overall flowchart of a method for early warning of pollution insulators of power transmission lines provided in an embodiment of the present invention;

[0048] Figure 2 A detailed flowchart of a method for early warning of pollution insulators of transmission lines provided in an embodiment of the present invention;

[0049] Figure 3 A schematic diagram of a power transmission line provided in an embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of current traveling wave detection provided in an embodiment of the present invention. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] This invention provides a method for early warning of pollution insulators of transmission lines, which solves the technical problems of existing methods for calibrating pollution levels requiring power outages or inspections on towers, resulting in inconvenience and power outage losses, and the inability to assess the pollution accumulation of the entire line in real time and to grasp the equivalent salt density value of the transmission line.

[0053] Figure 1 This is a flowchart of a method for early warning of pollution insulators of transmission lines provided by an embodiment of the present invention, including the following steps:

[0054] Step S10: Obtain historical daily current traveling wave data and historical meteorological data for the transmission line. (See also...) Figure 3 and Figure 4 As shown, "small station" and "large station" refer to substations in the transmission line. The actual transmission line and the substations at both ends are abstracted into a line segment model. The transmission line itself is a line segment, and the two endpoints are often represented by "small station" and "large station". The discharge point refers to the starting position of the current traveling wave. The sampling time, wave velocity and sensor location of the transmission line current traveling wave are obtained by sensors on both sides of the discharge point. The historical meteorological data includes historical rainfall, humidity, wind speed and air quality index.

[0055] Step S20: Calculate the equivalent salt density value along the transmission line on the current day based on the historical daily current traveling wave data and historical meteorological data of the transmission line.

[0056] Specifically, see Figure 2 As shown, the calculation of the equivalent salt density value along the transmission line on the current day based on historical daily current traveling wave data and historical meteorological data includes:

[0057] Step S201: Based on the historical daily current traveling wave data of the transmission line, obtain the historical daily discharge result table.

[0058] Specifically, see Figure 4As shown, L is the distance between the sensors on both sides of the discharge point, L1 is the distance from the discharge point to the sensor on the side closer to the small station, v is the current traveling wave velocity, and t1 and t2 are the times when the sensors on both sides of the discharge point detect the current traveling wave. Based on the sampling time, traveling wave velocity, and sensor location of the transmission line current traveling wave, the distances d1 and d2 from the detection equipment on both sides of the discharge point to the small station, and the larger traveling wave amplitude a detected by the detection equipment on both sides of the discharge point are calculated using the double-end positioning method. The calculated results are then saved to form a historical discharge result table.

[0059] Step S202: Calculate the daily discharge probability density at each point along the transmission line based on the historical daily discharge result table.

[0060] Specifically, based on historical discharge data and the following formula:

[0061]

[0062] The daily discharge probability density at each point along the transmission line is calculated, where x is the distance from each point along the line to the small station, σ is the standard deviation of the empirical positioning error, generally taken as 300 meters, and μ is the distance from the discharge point to the small station. x is a variable, and μ is a constant representing the specific positioning result. If the positioning result of a certain discharge is that the distance from the discharge point to the small station is 1000 meters, i.e., μ = 1000, it means that the discharge probability is highest at 1000 meters. For each point on both sides, the farther the distance, the lower the discharge probability. The overall discharge probability density follows a normal distribution.

[0063] Step S203: Calculate the daily pollution distribution along the transmission line based on the daily discharge probability density at each point along the transmission line.

[0064] Specifically, based on the daily discharge probability density at each point along the transmission line and the following formula:

[0065]

[0066] The daily pollution distribution along the transmission line is calculated, where c(x,y) is the pollution value of a point x meters away from the small station on the transmission line on day y, and n is the number of discharges on day t. In this formula:

[0067]

[0068] The discharge probability density is obtained by summing the results of multiple discharges within the same day. Then, starting from the first day of the data, the sums accumulated each day are summed again. That is, the sums are accumulated from the first day to the yth day to obtain the daily pollution distribution along the transmission line.

[0069] Step S204: Calculate the equivalent salt density distribution along the transmission line on the current day based on historical meteorological data and the daily distribution of accumulated pollution along the transmission line.

[0070] Specifically, according to the following formula:

[0071]

[0072] The equivalent salt density distribution along the transmission line on the current day is calculated, where E(x,d) is the equivalent salt density value calibrated on-site at point x on day d, and c(x,d) is the dirt accumulation value of meter x of the transmission line on day d when cleaning the transmission line. The on-site equivalent salt density calibration values ​​of each point on the line on day d are obtained. Based on this formula, the dirt accumulation distribution along the line on the current day calculated in step S203 is converted into the equivalent salt density distribution along the line on the current day. The equivalent salt density distribution is a set of equivalent salt density values ​​of each point on the transmission line for all dates. It is a two-dimensional distribution map that can reflect the historical equivalent salt density development trend and the distribution of equivalent salt density at each point along the transmission line in real time.

[0073] Step S30: If the equivalent salt density value along the transmission line on that day exceeds the preset equivalent salt density threshold, an insulator pollution warning signal is sent.

[0074] Specifically, based on the equivalent salt density distribution obtained in step S204, the equivalent salt density value is further obtained, and the obtained equivalent salt density value for the day is compared with the preset equivalent salt density threshold. If the equivalent salt density value along the transmission line for the day exceeds the preset equivalent salt density threshold, an insulator pollution warning signal is sent. The insulator pollution warning method of the present invention can assess the pollution situation of the entire line in real time and online without power outages or inspections on towers, and can grasp the equivalent salt density value of the transmission line and issue a warning signal.

[0075] As an optional implementation, in one embodiment of the invention, see [link to relevant documentation]. Figure 2 As shown, after calculating the daily discharge probability density of each point along the transmission line based on the historical daily discharge result table, the daily discharge probability density of each point along the transmission line is corrected according to distance weight and amplitude weight. According to the principle of double-end positioning, the closer to the midpoint of the detection section, the more accurate the result. At the same time, the larger the traveling wave amplitude, the greater the discharge intensity and the more severe the pollution. The daily discharge probability density of each point along the transmission line is superimposed with distance weight and amplitude weight to obtain the corrected daily discharge probability density of each point along the transmission line, making the obtained discharge probability density result more accurate.

[0076] As an optional implementation, in one embodiment of the invention, see [link to relevant documentation]. Figure 2As shown, the correction of the daily discharge probability density at each point along the transmission line based on distance weight and amplitude weight includes correcting the daily discharge probability density at each point along the transmission line according to the following formula:

[0077]

[0078] In the historical daily discharge results tables d1 and d2, the distances from the detection equipment on both sides of the discharge point to the small station are represented by d1 and d2, respectively. 'a' represents the larger traveling wave amplitude detected by the detection equipment on both sides of the discharge point in the historical daily discharge results table, and 'w(x)' represents the distance weight of the discharge point in the historical daily discharge results table.

[0079]

[0080] w(x) is equivalent to the triangular envelope, which is the region between the two detection devices. The distance weight of the midpoint is 1, and the distance weight of the two ends gradually decreases to 0. The closer the discharge point is to the middle, the more accurate the detection result is.

[0081] As an optional implementation, in one embodiment of the invention, see [link to relevant documentation]. Figure 2 As shown, the process of calculating the equivalent salt density distribution along the transmission line on a given day based on historical meteorological data and the daily distribution of accumulated pollution along the line includes: firstly, correcting the daily distribution of accumulated pollution along the line based on historical meteorological data; secondly, correcting the daily distribution of accumulated pollution along the line based on the most recent insulator cleaning record; and finally, calculating the daily equivalent salt density distribution map along the line based on the most recent on-site equivalent salt density calibration value at each point on the transmission line and the second corrected daily distribution of accumulated pollution along the line.

[0082] Specifically, the historical meteorological data includes historical rainfall, humidity, wind speed, and air quality index, firstly based on historical meteorological data and the following formula:

[0083] c ′ (x,y)| y≥d =c(x,y)| y≥d ·e -kA(x,d) ;

[0084] The calculation yielded the first revised distribution of accumulated pollution along the route on that day.

[0085] Then, according to the following formula:

[0086] c ″ (x,y)| y≥d =max(c ′ (x,y)| y≥d -c(x,d),0);

[0087] The second revised distribution of accumulated pollution along the route on that day was calculated.

[0088] Finally, based on the most recent on-site equivalent salt density calibration value at each point along the transmission line, the second revised daily distribution of accumulated pollution along the line, and the following formula:

[0089]

[0090] The second revised daily pollution distribution along the route was transformed into an equivalent salt density distribution map along the route on the same day.

[0091] As an optional implementation, in one embodiment of the invention, see [link to relevant documentation]. Figure 2 As shown, the first correction of the daily pollution distribution along the railway line based on historical meteorological data includes the first correction of the daily pollution distribution along the railway line according to the following formula:

[0092] c ′ (x,y)| y≥d =c(x,y)| y≥d ·e -kA(x,d) ;

[0093] Where e is the natural constant, k is the insulator material coefficient, A(x,d) is the meteorological data of the point x meters away from the small station on day d, and:

[0094] A(x,d)=H(x,d)+S(x,d)+Q(x,d)+3R(x,d);

[0095] H(x,d) represents humidity, S(x,d) represents wind speed, Q(x,d) represents air quality index, R(x,d) represents rainfall, and A(x,d) represents the normalized historical quantiles of these four meteorological data sets. This involves sorting these four meteorological data sets from smallest to largest and then converting the data sets into relative position percentages within this sequence, ranging from 0% to 100%. Taking humidity as an example, a higher percentage value indicates higher humidity, reflecting the impact of meteorological environmental factors on the daily accumulation of dirt on the insulator surface. Simultaneously, the insulator material coefficient reflects the adhesion ability of dirt to the material surface. Generally, composite insulators have smaller k-values, while ceramic insulators have larger k-values, according to the formula:

[0096] c ′ (x,y)| y≥d =c(x,y)| y≥d ·e -kA(x,d) ;

[0097] The first correction was made to the distribution of accumulated pollution along the line on that day, taking into full account meteorological environmental factors such as rainfall washing away the pollution on the transmission lines, wind speed increasing its growth rate, and humidity and air quality index increasing its equivalent salt density, so as to make the test results more accurate and reliable.

[0098] As an optional implementation, in one embodiment of the invention, see [link to relevant documentation]. Figure 2 As shown, the second correction of the daily pollution distribution along the line based on the most recent insulator cleaning record includes correcting the daily pollution distribution along the line based on the following formula:

[0099] c ″ (x,y)| y≥d =max(c ′ (x,y)| y≥d -c(x,d),0);

[0100] Among them, c ′ (x,y) represents the pollution accumulation value of the x-meter section of the transmission line after cleaning on day d, and c(x,d) represents the pollution accumulation value of the x-meter section of the transmission line on the day of cleaning on day d. The most recent insulator cleaning record of the transmission line is obtained, i.e., the most recent insulator pollution cleaning date is day d. The pollution values ​​after day d are subtracted from the pollution value on the day of cleaning, and the pollution value is not less than zero. Based on this formula, the daily pollution distribution along the line is corrected a second time, incorporating the influencing factors of daily transmission line cleaning into the detection results, further improving the accuracy and reliability of the transmission line insulator pollution detection results.

[0101] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0102] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0103] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A method for early warning of pollution insulators of transmission lines, characterized in that, include: Acquire historical daily current traveling wave data and historical meteorological data for transmission lines; The equivalent salt density value along the transmission line on that day was calculated based on historical daily current traveling wave data and historical meteorological data. The calculation of the equivalent salt density value along the transmission line on the current day, based on historical daily current traveling wave data and historical meteorological data, includes: Based on the historical daily current traveling wave data of the transmission line, a table of historical daily discharge results is obtained; Calculate the daily discharge probability density at each point along the transmission line based on the historical daily discharge results table; The daily distribution of accumulated pollution along the transmission line is calculated based on the daily discharge probability density at various points along the line. The equivalent salt density distribution along the transmission line on that day was calculated based on historical meteorological data and the daily distribution of accumulated pollutants along the transmission line. If the equivalent salt density value along the transmission line on that day exceeds the preset equivalent salt density threshold, an insulator pollution warning signal will be sent.

2. The method for early warning of pollution insulators of transmission lines according to claim 1, characterized in that, The calculation of the daily discharge probability density at each point along the transmission line based on the historical daily discharge result table includes: The daily discharge probability density at each point along the transmission line is calculated using the following formula: ； in, This represents the distance from each point along the line to the small station. The standard deviation of the empirical positioning error is typically taken as 300 meters. This is the distance from the discharge point to the small station.

3. The method for early warning of pollution insulators of transmission lines according to claim 2, characterized in that, The calculation of the daily pollution distribution along the transmission line based on the daily discharge probability density at various points along the transmission line includes: The daily pollution distribution along the transmission line is calculated using the following formula: ； in, The distance between the transmission line and the small station The point of meters at the 1st The filth value of the sky, For the first Number of discharges per day.

4. The method for early warning of pollution insulators of transmission lines according to claim 3, characterized in that, The equivalent salt density distribution along the transmission line on the current day, calculated based on historical meteorological data and the daily pollution distribution along the transmission line, includes: The equivalent salt density distribution along the transmission line on that day can be calculated using the following formula: ； in, For the first Heaven is The equivalent salt density value was determined on-site. For the first The day's power transmission lines were being cleaned. The amount of dirt accumulated in rice.

5. The method for early warning of pollution insulators of transmission lines according to claim 2, characterized in that, After calculating the daily discharge probability density at each point along the transmission line based on the historical daily discharge result table, the process includes: The daily discharge probability density at each point along the transmission line is corrected based on distance weight and amplitude weight.

6. The method for early warning of pollution insulators of transmission lines according to claim 5, characterized in that, The step of correcting the daily discharge probability density at each point along the transmission line based on distance weight and amplitude weight includes: The daily discharge probability density at each point along the transmission line is corrected according to the following formula: ； in, and The historical daily discharge results table shows the distance from the detection equipment on both sides of the discharge point to the small station. The larger traveling wave amplitude value detected by the detection equipment on both sides of the discharge point in the historical daily discharge results table. The distance weights for discharge points in the historical daily discharge results table.

7. The method for early warning of pollution insulators of transmission lines according to claim 1, characterized in that, The calculation of the equivalent salt density distribution along the transmission line on that day, based on historical meteorological data and the daily distribution of accumulated pollution along the line, includes: The distribution of accumulated pollution along the route was revised for the first time based on historical meteorological data. Based on the most recent insulator cleaning record, the distribution of accumulated dirt along the line on the day of the first correction will be corrected a second time. The equivalent salt density distribution map along the transmission line on that day was calculated based on the most recent on-site equivalent salt density calibration value at each point of the transmission line and the second revised daily distribution of accumulated pollution along the line.

8. The method for early warning of pollution insulators of transmission lines according to claim 7, characterized in that, The first correction of the daily pollution distribution along the route based on historical meteorological data includes: The first correction to the daily pollution distribution along the route is made based on the following formula: ； in, It is a natural constant. The insulator material coefficient, For the distance from the small station The point of meters at the 1st Weather data for the day.

9. The method for early warning of pollution insulators of transmission lines according to claim 7, characterized in that, The second correction, based on the most recent insulator cleaning record, of the daily distribution of accumulated dirt along the line after the first correction, includes: The daily pollution distribution along the line, which was corrected in the first correction, is then corrected a second time using the following formula: ； in, For the first After the power transmission lines were cleaned, the power transmission lines were... The amount of dirt accumulated in rice, For the first The day's power transmission lines were being cleaned. The amount of dirt accumulated in rice.

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