A dynamic switching method for the allowable current-carrying capacity of a transmission line

Abstract

The present invention discloses a method for dynamically switching the allowable current-carrying capacity of a transmission line, which includes the following steps: Step S1, reading the ambient temperature. The dynamic switching of the allowable current-carrying capacity of the line is based on the ambient temperature sensed by the D5000 system to achieve the fusion of partial environmental data and internal equipment limit data; Step S2, setting the switching strategy for the allowable current-carrying capacity of the line; Step S3, manually setting the automatic adjustment mode or the manual intervention adjustment mode. The allowable current-carrying capacity limit of the transmission line is in a matching state with the ambient temperature, avoiding the problems of excessive or too small limit setting, giving full play to the power supply capacity of the transmission line in a reasonable manner, ensuring the safe and reliable operation of the transmission line. According to the needs of the power grid operation mode, the real-time matching degree of the current-carrying capacity and the ambient temperature can be further increased. The D5000 system automatically implements dynamic revision of the allowable current-carrying capacity limit of the transmission line, eliminates the drawbacks of the manual one-size-fits-all adjustment mode, realizes accurate correction of the limit, and reduces the manual workload at the same time.

Description

Technical Field

[0001] The present invention relates to a method for dynamically switching the allowable current-carrying capacity of a transmission line, belonging to the technical field of power grids. Background Art

[0002] Currently, support systems such as D5000 used in the regulation system cannot sense the ambient temperature of the line operation. Since the current-carrying capacity of the line cannot be automatically switched according to the ambient temperature, it can only be manually switched uniformly by personnel at specific time periods. For example, during the high-temperature period in summer from June to August, the current-carrying capacity of the line is switched to the limit value at 40°C for operation, and the current-carrying capacity of the line is switched to the limit value at 25°C for operation at other times. However, the ambient temperatures in different regions and at different times are constantly changing and are not the same. This one-size-fits-all limit switching method directly results in a mismatch between the allowable current-carrying capacity of the line and the ambient temperature. In extremely high-temperature weather (above 40°), the set allowable current-carrying capacity of the line may be too large, causing damage to the line. When the ambient temperature is below 40°, the set allowable current-carrying capacity of the line will be too small, unable to fully utilize the power supply capacity of the transmission line and affecting the normal power consumption of users. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for dynamically switching the allowable current-carrying capacity of a transmission line, which fully applies the concepts of network interconnection and big data. By uploading the ambient temperature value in real time, the D5000 system can dynamically sense the ambient temperature data of the line, and then the D5000 system switches the allowable current-carrying capacity of the line according to corresponding rules. Through active control, the allowable current-carrying capacity of the line is actively switched under different ambient temperatures to achieve the matching of the allowable current-carrying capacity of the line and the ambient temperature.

[0004] To solve the above problems, the technical solutions adopted by the present invention are as follows:

[0005] A method for dynamically switching the allowable current-carrying capacity of a transmission line includes the following steps:

[0006] Step S1, reading the ambient temperature. The dynamic switching of the allowable current-carrying capacity of the line is based on the ambient temperature sensed by the D5000 system to achieve the integration of external environment data and internal device limit data;

[0007] Step S2, setting the switching strategy of the allowable current-carrying capacity of the line;

[0008] Step S3, manually setting the automatic adjustment mode or the manual intervention adjustment mode.

[0009] As a further improvement of the present invention,

[0010] In step S1, the D5000 system sensing the ambient temperature includes the following three schemes:

[0011] Solution 1: Through the provincial company's meteorological information system, taking the substation as a unit, upload the township-level meteorological data to the D5000 system;

[0012] Solution 2: Install temperature sensors at each station and upload the ambient temperature value to the D5000 system in real time with each station as a unit;

[0013] Solution 3: Select several typical areas to install temperature sensors and upload the ambient temperature value to the D5000 system in real time.

[0014] As a further improvement of the present invention,

[0015] In step S1, the line allowable current-carrying capacity switching strategy includes the full-line allowable current-carrying capacity definition principle, the overhead line allowable current-carrying capacity definition principle, the overhead line allowable current-carrying capacity adjustment strategy, and the full-line allowable current-carrying capacity switching rule.

[0016] As a further improvement of the present invention,

[0017] The full-line allowable current-carrying capacity definition principle is as follows: The line allowable current-carrying capacity is restricted by the transmission carrier itself and at the same time by the allowable current-carrying capacity of each component of the line. To ensure the safety of the equipment, it is stipulated that the minimum allowable current-carrying capacity of each component is used as the set value of the line allowable current-carrying capacity, that is:

[0018] I 线 =min(I1, I2…I n )

[0019] Where: I 线 represents the full-line allowable current-carrying capacity.

[0020] As a further improvement of the present invention,

[0021] The overhead line allowable current-carrying capacity definition principle is as follows: The allowable current-carrying capacity of the cable and the line CT is a fixed value, which is defined as a non-temperature-limited component, while the overhead line is defined as a temperature-limited component;

[0022] Taking each transmission line as a unit to monitor the operating environment temperature of the line, manually set the county area traversed by each line. The system monitors the temperature of these 3 counties and takes the highest temperature value as the current operating environment temperature of the line.

[0023] As a further improvement of the present invention,

[0024] For the case where a line contains multiple types of overhead lines, each part of the overhead line is regarded as a complete transmission line and the corresponding definition rules are adopted.

[0025] As a further improvement of the present invention,

[0026] The adjustment strategy for the allowable current-carrying capacity of overhead lines is as follows: The allowable current-carrying capacity of overhead lines can be set with different adjustment periods. To avoid overly frequent switching of the allowable current-carrying capacity of the line, the adjustment period is set to 24 hours;

[0027] Each natural day is set as a complete adjustment period. The highest temperature value collected during the previous day is defined as the operating environment temperature reference value for the transmission line on the next day. The line allowable current-carrying capacity correction factor corresponding to the ambient temperature is set as the reference correction factor. After the ambient temperature change on the next day meets the switching rule, the correction factor is adjusted, and the line allowable current-carrying capacity is changed accordingly;

[0028] The system collects the operating environment temperature of each transmission line once per hour, generates the reference correction factor, and completes the adjustment of the correction factor by comparing the collected real-time temperature with the reference value.

[0029] As a further improvement of the present invention,

[0030] The adjustment of the correction factor includes an upward adjustment rule and a downward adjustment rule;

[0031] The upward adjustment rule is: When the temperature collected at any time point is higher than the reference value, it is adjusted upward by one temperature level, and this temperature is redefined as the reference value for the current day, and the reference correction factor is adjusted at the same time;

[0032] The downward adjustment rule is: When the daily highest temperature value is lower than the reference value for the current day, it is adjusted downward by one temperature level, this temperature is defined as the reference value for the new day, and the reference correction factor is adjusted.

[0033] As a further improvement of the present invention,

[0034] The switching rule for the allowable current-carrying capacity of the entire line is as follows: According to the definition rule of the allowable current-carrying capacity of each component in the entire line and considering the ambient temperature, the allowable current-carrying capacity of the line is defined as:

[0035] I 线W =min(I 线1w ,I 线2w ,…,I 线iw ,…I 线mw ,I1,I2…,I j ,…,I n )

[0036] Where: I 线W represents the allowable current-carrying capacity of the entire line under the current ambient temperature;

[0037] I 线iw represents the allowable current-carrying capacity of the i-th type of overhead line of the line under the current ambient temperature, 1 ≤ i ≤ m;

[0038] Ij Denote the allowable current-carrying capacity of the jth non-temperature-limited component circuit, including cables and line CTs, where \(1\leq j\leq n\).

[0039] As a further improvement of the present invention,

[0040] In step S3, the D5000 system includes two modes: automatic adjustment and manual intervention adjustment. It can be set manually according to needs, but the two modes cannot coexist on the same transmission line, and only one of them can be set. The automatic adjustment mode autonomously completes according to the established rules and will not be elaborated here. The following will describe the manual intervention adjustment mode.

[0041] The operation process of the manual intervention adjustment mode is as follows:

[0042] Step S41, when the system determines that the correction coefficient needs to be adjusted according to logical operations, the system uses an obvious alarm method to prompt the duty personnel and displays the details of the lines that need to be adjusted in the form of a list;

[0043] Step S42, the system defaults to not execute. The duty personnel modify it to execute by selecting item by item. The operator and the guardian need to input passwords respectively before it can be executed;

[0044] Step S43, the execution result is displayed in the form of a list indicating whether the switching is successful or not. Right-click on the current value of a certain switch on the D5000 screen, and the corresponding line current-carrying capacity correction coefficient and temperature can be displayed in the pop-up drop-down menu;

[0045] Step S44, all relevant execution situations are automatically recorded and saved in the historical database, and the records can be queried at any time according to needs.

[0046] Furthermore, a main switch is set in the D5000 system, and the function of the manual intervention adjustment mode can be turned on or off according to needs.

[0047] The beneficial effects of adopting the above technical solutions are as follows:

[0048] 1. The allowable current-carrying capacity limit of the transmission line is in a matching state with the ambient temperature, avoiding the problems of excessive or too small limit settings, giving full play to the power supply capacity of the transmission line in a reasonable manner, ensuring the safe and reliable operation of the transmission line. According to the needs of the power grid operation mode, such as shortening the adjustment cycle and increasing the number of adjustments, the real-time matching degree between the current-carrying capacity and the ambient temperature can be further increased.

[0049] 2. The D5000 system automatically implements dynamic revision of the allowable current-carrying capacity limit of the transmission line, eliminating the drawbacks of the manual one-size-fits-all adjustment mode. While achieving accurate correction of the limit value, it reduces the manual workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0051] Figure 1 is the architecture diagram of the data transmission channel of the present invention;

[0052] Figure 2 is the interface diagram for setting the allowable current-carrying capacity of the overhead line at different temperatures of the present invention;

[0053] Figure 3 is the interface diagram for adjusting the allowable current-carrying capacity of the line of the present invention;

[0054] Figure 4 is the interface diagram for querying the switching result of the allowable current of the line of the present invention;

[0055] Figure 5 is the correction coefficient table of the transmission line at different temperatures;

[0056] Figure 6 is the adjustment strategy table of the allowable current-carrying capacity of the overhead line. Specific Embodiments

[0057] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way restricts the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0058] It should be noted that the terms used here are only for describing specific embodiments and are not intended to limit the exemplary embodiments of the present application. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0059] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation.

[0060] Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: Similar reference numerals and letters denote similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0061] In the description of the present application, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present application; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0062] At different ambient temperatures, the allowable current-carrying capacity values of transmission lines (overhead lines) are different. According to the allowable temperature of aluminum alloy conductors being 70 degrees and the ambient air temperature being 25 degrees, the correction factor for the allowable current-carrying capacity of the line is 1. When the ambient temperature changes, the allowable current-carrying capacity of the line should be the base value multiplied by the correction factor corresponding to the temperature. The correction factors at different temperatures are as Figure 5 shown in the table.

[0063] This embodiment provides a method for dynamically switching the allowable current-carrying capacity of a transmission line, the core content of which is the fusion of external environmental data and internal equipment limit data. Currently, from the basic conditions of the State Grid system, there is a channel for reading external network data and pushing it to the D5000 system, and the data transmission channel architecture is as Figure 1 shown.

[0064] A method for dynamically switching the allowable current-carrying capacity of a transmission line includes the following steps:

[0065] Step S1, reading the ambient temperature. The dynamic switching of the allowable current-carrying capacity of the line is based on the ambient temperature sensed by the D5000 system to achieve the fusion of external environmental data and internal equipment limit data;

[0066] Step S2, set the line allowable current-carrying capacity switching strategy;

[0067] Step S3, manually set the automatic adjustment mode or the manual intervention adjustment mode.

[0068] Furthermore,

[0069] In step S1, the D5000 system senses the ambient temperature including the following three solutions:

[0070] Solution 1: Through the provincial company's meteorological information system, taking the substation as a unit, upload the township-level meteorological data to the D5000 system;

[0071] Solution 2: Install temperature sensors at each station and upload the ambient temperature value to the D5000 system in real time based on the station;

[0072] Solution 3: Select several typical areas to install temperature sensors and upload the ambient temperature value to the D5000 system in real time.

[0073] Furthermore,

[0074] In step S1, the line allowable current-carrying capacity switching strategy includes the full-line allowable current-carrying capacity definition principle, the overhead line allowable current-carrying capacity definition principle, the overhead line allowable current-carrying capacity adjustment strategy, and the full-line allowable current-carrying capacity switching rule.

[0075] Specifically,

[0076] 1) Full-line allowable current-carrying capacity definition principle

[0077] Under normal circumstances, a line only contains single-type components of the same material. For example, if the line material is a certain type of ACSR or cable, the allowable current-carrying capacity of each part of the line is the same. In special cases, the same line may be composed of lines, cables, or components of the same material with different model specifications, and the allowable current-carrying capacity of each part of the line is not the same. In addition, the allowable current-carrying capacity of the line is not only limited by the transmission carrier itself, but also cannot exceed the allowable current-carrying capacity limits of each component such as the line CT. To ensure the safety of the equipment, it is stipulated that the minimum allowable current-carrying capacity of each component is used as the set value of the line allowable current-carrying capacity, that is:

[0078] I 线 = min(I1, I2...I n )

[0079] Among them: I 线 represents the full-line allowable current-carrying capacity;

[0080] I i represents the allowable current-carrying capacity of the i-th type of component of the line, including overhead lines, cables, and line CTs, where 1 ≤ i ≤ n.

[0081] 2) Overhead line allowable current-carrying capacity definition principle

[0082] Due to the existence of the cable sheath and usually being directly buried underground, the power transmission capacity of the cable is less affected by the change of the atmospheric ambient temperature. In addition, the allowable current-carrying capacity of the line CT generally does not consider the change of the ambient temperature. Therefore, the allowable current-carrying capacity of the cable and the line CT is a fixed value, which is defined as a non-temperature-limited component, while the overhead line is defined as a temperature-limited component.

[0083] Monitor the operating ambient temperature of each transmission line as a unit. Manually set the counties or districts through which each line passes. For example, a certain 110 kV line passes through three counties or districts, namely County A, County B, and County C. After manual setting, the system monitors the temperatures of these 3 counties or districts and takes the highest temperature value as the current operating ambient temperature of this line.

[0084] As Figure 2 shown, the D5000 system sets nine stepped temperature values of 5, 10, 15, 20, 25, 30, 35, 40, and 45. Each temperature corresponds to a different current-carrying capacity correction factor. When the ambient temperature ≤ 5°C, it is calculated according to 5°C. When 5°C < ambient temperature ≤ 10°C, it is calculated according to 10°C, and so on. In addition, to ensure a safety margin, the ambient temperature measurement can be revised upward as the D5000 perceived temperature. For example, if it is stipulated that the ambient temperature is uniformly increased by 3°C, when the ambient temperature is 15°C, the D5000 receives a perceived temperature of 18°C.

[0085] For the case where a line contains multiple types of overhead lines, each part of the overhead line can be regarded as a complete transmission line, and the corresponding definition rules can be adopted.

[0086] 3) Overhead line allowable current-carrying capacity adjustment strategy, as Figure 6 shown in the table:

[0087] The line allowable current-carrying capacity adjustment strategy mentioned in this part only refers to the overhead line part. According to needs, different adjustment periods can be set for the line allowable current-carrying capacity. To avoid overly frequent switching of the line allowable current-carrying capacity, the adjustment period is usually set to 24 hours. This article takes a 24-hour period as an example for illustration.

[0088] Set each natural day as a complete adjustment period. Define the highest temperature value collected in the previous day during the day as the operating ambient temperature reference value of the transmission line for the next day. Set the line allowable current-carrying capacity correction factor corresponding to the ambient temperature as the reference correction factor. After the ambient temperature change on the next day meets the switching rule, adjust the correction factor, and the line allowable current-carrying capacity changes accordingly.

[0089] The system collects the operating ambient temperature of each transmission line once per hour, generates the reference correction factor, and completes the adjustment of the correction factor by comparing the collected real-time temperature with the reference value. Note that the temperature adjustment rules for upward and downward adjustments are different.

[0090] The details are as follows:

[0091] Upward adjustment rule: When the temperature collected at any time point is higher than the reference value, adjust it upward by one temperature level, redefine this temperature as the reference value for the day, and at the same time adjust the reference correction coefficient.

[0092] Downward adjustment rule: Only when the daily maximum temperature value is lower than the reference value for the day can it be adjusted downward by one temperature level, define this temperature as the reference value for the new day, and adjust the reference correction coefficient.

[0093] 4) All-line allowable current-carrying capacity switching rule

[0094] According to the all-line allowable current-carrying capacity definition rules for each component and considering the ambient temperature, the line allowable current-carrying capacity is defined as:

[0095] I 线W =min(I 线1w , I 线2w ,…, I 线iw ,…I 线mw , I1, I2…, I j ,…, I n )

[0096] Where: I 线W represents the all-line allowable current-carrying capacity under the current ambient temperature;

[0097] I 线iw represents the allowable current-carrying capacity of the i-th type of overhead line of the line under the current ambient temperature, 1 ≤ i ≤ m;

[0098] I j represents the allowable current-carrying capacity of the line of the j-th non-temperature-limited component, including cables and line CTs, 1 ≤ j ≤ n.

[0099] When the system determines that the correction coefficient needs to be adjusted according to the switching rule, the system sends a control strategy, uses an obvious warning method to prompt the duty personnel, and displays the line details that need to be adjusted in the form of a list. The application interface for adjusting the line allowable current-carrying capacity is as Figure 3 shown:

[0100] Furthermore,

[0101] The system includes two modes: automatic adjustment and manual intervention adjustment, which can be set manually according to needs, but the two modes cannot coexist on the same transmission line and only one of them can be set. The automatic adjustment mode autonomously completes according to the established rules and will not be elaborated here.

[0102] In step S3, the D5000 system includes two modes: automatic adjustment and manual intervention adjustment. It can be set manually according to needs, but the two modes cannot coexist on the same transmission line and only one of them can be set. The automatic adjustment mode autonomously completes according to the established rules and will not be elaborated here. The following will explain the manual intervention adjustment mode.

[0103] The operation process of the manual intervention adjustment mode is as follows:

[0104] Step S41, when the system determines that the correction coefficient needs to be adjusted according to logical operations, the system uses an obvious warning method to prompt the duty personnel and displays the line details to be adjusted in the form of a list;

[0105] Step S42, the system defaults to not execute. The duty personnel modify it to execute by selecting item by item. The operator and the guardian can execute it only after entering the passwords respectively and passing the verification;

[0106] Step S43, the execution result is displayed in the form of a list indicating whether the switching is successful or not. Right-click on the current value of a certain switch on the D5000 screen, and the line current-carrying capacity correction coefficient and temperature corresponding to the switch can be displayed in the pop-up drop-down menu;

[0107] Step S44, all relevant execution situations are automatically recorded and saved in the historical database, and the records can be queried at any time according to needs, as Figure 4 shown.

[0108] Furthermore, a main switch is set in the D5000 system, and the function of the manual intervention adjustment mode can be turned on or off according to needs.

[0109] Applying the switching method of this embodiment: The allowable current-carrying capacity limit of the transmission line is in a matching state with the ambient temperature, avoiding the problems of too large or too small limit settings, giving full play to the power supply capacity of the transmission line reasonably, ensuring the safe and reliable operation of the transmission line. According to the needs of the power grid operation mode, such as shortening the adjustment cycle and increasing the adjustment times, the real-time matching degree of the current-carrying capacity and the ambient temperature can be further increased.

[0110] The D5000 system automatically implements dynamic revision of the allowable current-carrying capacity limit of the transmission line, eliminates the disadvantages of the manual one-size-fits-all adjustment mode, realizes accurate correction of the limit value, and reduces the manual workload at the same time.

Claims

1. A method for dynamically switching the allowable current-carrying capacity of a transmission line, characterized in that, It includes the following steps: Step S1, reading the ambient temperature. The dynamic switching of the allowable current-carrying capacity of the line is based on the ambient temperature sensed by the D5000 system, realizing the fusion of external environmental data and internal equipment limit data; The switching strategy of the allowable current-carrying capacity of the line includes the definition principle of the allowable current-carrying capacity of the whole line, the definition principle of the allowable current-carrying capacity of the overhead line, the adjustment strategy of the allowable current-carrying capacity of the overhead line, and the switching rule of the allowable current-carrying capacity of the whole line; The definition principle of the allowable current-carrying capacity of the whole line is as follows: The allowable current-carrying capacity of the line is restricted by the transmission carrier itself and at the same time by the allowable current-carrying capacity of each component of the line. To ensure the safety of the equipment, it is stipulated that the minimum allowable current-carrying capacity of each component is used as the setting value of the allowable current-carrying capacity of the line, that is: I 线 = min(I1, I2… I n ) Where: I 线 represents the allowable current-carrying capacity of the entire line; The definition principle of the allowable current-carrying capacity of the overhead line is as follows: The allowable current-carrying capacity of the cable and the line CT is a fixed value, which is defined as a non-temperature-limited component, while the overhead line is defined as a temperature-limited component; Taking each transmission line as a unit to monitor the operating ambient temperature of the line, manually setting the counties and regions crossed by each line. The system monitors the temperatures of these 3 counties and regions and takes the highest temperature value as the current operating ambient temperature of the line; The adjustment strategy of the allowable current-carrying capacity of the overhead line is as follows: The allowable current-carrying capacity of the overhead line can be set with different adjustment periods. To avoid too frequent switching of the allowable current-carrying capacity of the line, the adjustment period is set to 24 hours; Each natural day is set as a complete adjustment period. The highest temperature value collected in the previous day is defined as the operating ambient temperature reference value of the transmission line on the next day. The correction coefficient of the allowable current-carrying capacity of the line corresponding to the ambient temperature is set as the reference correction coefficient. After the ambient temperature change on the next day meets the switching rule, the correction coefficient is adjusted, and the allowable current-carrying capacity of the line is changed accordingly; The system collects the operating ambient temperature of each transmission line once an hour to generate the reference correction coefficient, and completes the adjustment of the correction coefficient by comparing the collected real-time temperature with the reference value The switching rule of the allowable current-carrying capacity of the whole line is as follows: According to the definition rule of the allowable current-carrying capacity of each component of the whole line and taking the ambient temperature into consideration, the allowable current-carrying capacity of the line is defined as: I 线W = min(I 线1w , I 线2w , …, I 线iw , …, I 线mw , I1, I2…, I j , …, I n ) Among which I 线w represents the allowable current-carrying capacity of the whole line under the current ambient temperature; I 线iw Indicates the allowable current-carrying capacity of the i-th overhead line of the line under the current ambient temperature, 1im; I j Denotes the allowable current-carrying capacity of the j-th non-temperature-limited component circuit, including cables and line CTs, 1 ≤ j ≤ n; Step S2, setting the switching strategy of the allowable current-carrying capacity of the line; Step S3, manually setting the automatic adjustment mode or the manual intervention adjustment mode.

2. The method for dynamically switching the allowable current-carrying capacity of a transmission line according to claim 1, characterized in that, In step S1, the D5000 system sensing the ambient temperature includes the following three schemes: Scheme 1, through the provincial company meteorological information system, taking the substation as the unit, uploading the township-level meteorological data to the D5000 system; Scheme 2, installing temperature sensors at each station and uploading the ambient temperature value to the D5000 system in real time with the station as the unit; Scheme 3, selecting several typical areas to install temperature sensors and uploading the ambient temperature value to the D5000 system in real time.

3. The method for dynamically switching the allowable current-carrying capacity of a transmission line according to claim 1, characterized in that, For the situation where a line contains multiple types of overhead lines, each part of the overhead line is regarded as a complete transmission line, and the corresponding definition rules are adopted.

4. The method for dynamically switching the allowable current-carrying capacity of a transmission line according to claim 1, characterized in that, The adjustment of the correction coefficient includes the upward adjustment rule and the downward adjustment rule; The upward adjustment rule is: When the temperature collected at any time point is higher than the reference value, it is adjusted upward by one temperature level, and this temperature is redefined as the reference value of the day, and at the same time, the reference correction coefficient is adjusted; The downward adjustment rule is as follows: when the daily maximum temperature value is lower than the benchmark value of the day, it is adjusted downward by one temperature level. The adjusted temperature is defined as the benchmark value of the new day, and the benchmark correction coefficient is adjusted.

5. The method for dynamically switching the allowable current-carrying capacity of a transmission line according to claim 1, characterized in that, In step S3, the operation process of the manual intervention adjustment mode is as follows: In step S41, when the system determines, according to logical operations, that the correction coefficient needs to be adjusted, the system uses an obvious warning method to prompt the duty personnel and displays the line details to be adjusted in the form of a list. In step S42, the system does not execute by default. The duty personnel modify it to execution by selecting item by item. The operator and the guardian can execute only after entering the passwords respectively and passing the verification. In step S43, the execution result is displayed in the form of a list indicating whether the switching is successful or not. Right-click on the current value of a certain switch on the D5000 screen, and the line current-carrying capacity correction coefficient and temperature corresponding to the switch can be displayed in the pop-up drop-down menu. In step S44, all relevant execution situations are automatically recorded and saved in the historical database, and the records can be queried at any time as needed.

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