A method and system for intelligent ice melting of ground wires of power transmission lines

Abstract

The technical solution adopted by the present invention is: a method and system for intelligent ice melting of ground wires of transmission lines, wherein the transmission lines include multiple lines, and the method includes the following steps: calculating the real-time ice safety of each ice melting section based on the real-time ice thickness prediction value of each ice melting section, the bearing capacity of the tower, the tension and cross-span distance of the ground wire, and the load of the hardware and insulators; sorting all ice melting sections according to the real-time ice safety of each ice melting section to form an ice melting sequence set, and selecting the ice melting section with the highest ice melting urgency to perform ice melting operations according to the ice melting sequence set; during the ice melting process, intelligently regulating the ice melting current according to real-time monitoring data, and selecting the fastest ice melting mode or the normal ice melting mode according to external instructions, and further subdividing the different modes into three strategies: aggressive, balanced, and conservative. The present invention can achieve efficient and safe ice melting operations under complex working conditions, significantly improving the operational reliability and ice melting efficiency of the transmission line.

Description

Technical Field

[0001] The present invention belongs to the technical field of power transmission lines, and in particular relates to a method and system for intelligently melting ice on a ground wire of a power transmission line. Background Art

[0002] As global energy demand continues to grow, the operational safety and reliability of power transmission systems are becoming increasingly important. During the operation of long-distance transmission lines, icing is a common occurrence due to complex climatic conditions. Especially in extreme environments such as winter or mountainous areas, icing can lead to line overloads, mechanical damage, and even widespread power outages. Therefore, efficiently and safely de-icing transmission lines is a key technical challenge for power grids in combating icing disasters.

[0003] At present, the main features of the ice melting method for transmission line ground wires are as follows:

[0004] (1) Constant current ice melting

[0005] Transmission line ice melting is typically accomplished by heating the line with a constant DC current, raising the line surface temperature to the ice melting point. This constant current is an empirical current value under fixed meteorological conditions and cannot be dynamically adjusted based on the line's real-time operating conditions. This can easily lead to unsuccessful ice melting due to insufficient current, prolonged ice melting time, or excessive current causing ground wire overheating.

[0006] (2) Melt ice in sections

[0007] Generally, the line is divided into several sections, and ice melting operations are carried out section by section. However, the decision of section switching often relies on manual judgment, and there is a lack of a systematic method for assessing the urgency of ice melting.

[0008] (3) Ice melting based on online monitoring

[0009] Existing ice-melting technologies incorporate online monitoring devices, which collect data such as ambient temperature, ice thickness, and ground temperature to provide a reference for ice melting. However, these methods are limited to monitoring and recording data and fail to directly link monitoring data to ice-melting strategies. As a result, ice-melting decisions are still primarily based on fixed rules, failing to fully utilize real-time monitoring information to optimize ice-melting operations.

[0010] (4) Single thawing strategy

[0011] The current ice-melting technology strategy is to use a constant current to melt the ice to ensure that the ground (conductor) wire temperature does not exceed the maximum allowable temperature. It does not adopt advanced ice-melting strategies and lacks comprehensive optimization capabilities for multiple lines and multiple working conditions.

[0012] Although existing technologies have made some progress in the field of ice melting for transmission lines, the following technical problems still exist:

[0013] (1) Lack of dynamic adaptability of ice melting current control

[0014] The ice melting current of existing ice melting technology is usually a preset constant value or an empirical value, which cannot be dynamically adjusted in real time according to different environmental conditions and ice thickness, resulting in low ice melting efficiency or safety hazards.

[0015] (2) Lack of systematic indicator evaluation for ice melting decision-making

[0016] Existing de-icing technologies lack a comprehensive safety indicator assessment system when selecting de-icing lines or optimizing the de-icing sequence. For example, key factors such as tower load-bearing capacity, ground conductor tension, cross-span distance, and the ultimate load of hardware and insulators are not systematically considered, and de-icing priority is primarily determined by manual experience.

[0017] (3) Inefficient multi-line collaborative ice melting

[0018] In a multi-line operation environment, existing methods are usually unable to effectively distinguish the urgency of different lines during the ice melting process. The lack of a multi-line collaborative ice melting optimization strategy based on real-time monitoring data may lead to uneven resource allocation or unreasonable ice melting sequence.

[0019] (4) Inflexible switching of ice-melting strategies

[0020] During ice-melting operations, different strategies can be employed to address different operating conditions (e.g., thick ice cover, harsh environmental conditions). However, existing ice-melting technologies are inadequate in switching strategies. They cannot flexibly switch between conservative, balanced, and aggressive ice-melting modes based on real-time data, which can easily lead to improper operation and waste of resources. Summary of the Invention

[0021] The purpose of the present invention is to address the deficiencies of the above-mentioned background technology and to provide a method and system for intelligent ice melting of the ground wire of a power transmission line, which can achieve efficient and safe ice melting operations under complex working conditions and significantly improve the operational reliability and ice melting efficiency of the transmission line.

[0022] The technical solution adopted by the present invention is: a method for intelligently melting ice on the ground wire of a power transmission line, wherein the power transmission line includes multiple lines, and comprises the following steps:

[0023] Calculate the real-time ice safety of each de-icing section based on the real-time ice thickness prediction value, tower bearing capacity, ground wire tension and cross-span distance, and hardware and insulator loads.

[0024] All ice-melting sections are sorted according to their real-time ice-covering safety to form an ice-melting sequence set. The ice-melting section with the highest ice-melting urgency is selected according to the ice-melting sequence set to perform the ice-melting operation:

[0025] The fastest ice melting mode or the normal ice melting mode is selected according to external instructions. The fastest ice melting mode or the normal ice melting mode includes an aggressive ice melting strategy, a balanced ice melting strategy, and a conservative ice melting strategy, in which the ice melting current values ​​are distributed in order from roughly small to large. The corresponding ice melting mode or ice melting strategy is switched according to the current ice melting constraint conditions of the ice melting section; the ice melting current is adjusted according to the monitoring data of the ice melting section.

[0026] In the above technical solution, monitoring points are arranged at three or more tower positions that are most susceptible to ice accumulation and three or more tower positions that are least susceptible to ice accumulation in each ice melting section to monitor the ambient temperature, ground temperature, wind speed and ice thickness.

[0027] In the above technical solution, the calculation process of the current icing safety degree of any ice-melting section includes: first, using the hierarchical analysis method to calculate the risk weight coefficients of ice thickness, poles, (conductor) ground wires, hardware and insulators, and then respectively calculating the ratio of the current ice thickness predicted value to its limit value, the ratio of the pole bearing capacity to its limit value, the ratio of the ground wire tension and cross-span distance to its limit value, the ratio of the hardware load to its limit value, and the ratio of the insulator load to its limit value for each monitoring point in the ice-melting section. Finally, based on the maximum value of each ratio and the corresponding weight, the ice safety index of the ice-melting section is calculated.

[0028] In the above technical solution, only the ice melting sections whose current ice thickness prediction value reaches the set threshold within the set time are added to the ice melting sequence set.

[0029] In the above technical solution, the ice melting strategy switching process in the fastest ice melting mode includes:

[0030] Prioritize the conservative ice-melting strategy: The smaller value of the minimum of the maximum fully covered ice-melting current and the minimum of the maximum partially covered ice-melting current at all monitoring points is taken as the ice-melting current. This ice-melting current should be greater than the minimum of the minimum ice-melting currents at all monitoring points. Otherwise, the strategy switches to the balanced strategy.

[0031] Balanced ice melting strategy: The smaller of the average of the maximum fully covered ice melting current and the maximum partially covered ice melting current at all monitoring points is used as the ice melting current. This ice melting current must be greater than the minimum of the minimum ice melting currents at all monitoring points. Otherwise, the strategy switches to the aggressive strategy.

[0032] Aggressive strategy: The smaller value of the maximum value of the maximum fully covered ice melting current and the minimum value of the maximum partially covered ice melting current at all monitoring points is taken as the ice melting current. This ice melting current should be greater than the minimum value of the minimum ice melting current at all monitoring points, otherwise it will be prompted that ice melting cannot be completed.

[0033] In the above technical solution, the ice melting strategy switching process in the normal ice melting mode includes:

[0034] Prioritize the conservative ice-melting strategy: The smaller value of the minimum of the remaining time ice-melting currents and the minimum of the maximum non-full ice-melting currents at all monitoring points is taken as the ice-melting current. This ice-melting current should be greater than the minimum of the minimum ice-melting currents at all monitoring points. Otherwise, the strategy switches to the balanced strategy.

[0035] Balanced ice melting strategy: The smaller of the average of the remaining time ice melting currents of all monitoring points and the maximum non-full ice melting current is used as the ice melting current. This ice melting current must be greater than the minimum of the minimum ice melting currents of all monitoring points. Otherwise, the strategy switches to the aggressive strategy.

[0036] Aggressive strategy: The smaller value of the maximum value of the remaining time melting current of all monitoring points and the minimum value of the maximum non-full ice melting current is taken as the melting current; this melting current should be greater than the minimum value of the minimum melting current of all monitoring points, otherwise it jumps to the fastest melting mode.

[0037] In the above technical solution, the ice-melting operation process of any ice-melting section includes: all monitoring points in the ice-melting section detect in real time whether the ground (conductor) temperature is less than the set limit; if so, the ice-melting section continues to perform the ice-melting operation according to the ice-melting current of the current strategy; otherwise, the ice-melting current is reduced under the current strategy.

[0038] In the above technical solution, the ice melting operation process of any ice melting section further includes: when the ice thickness of all monitoring points in the ice melting section reaches the set target value, the ice melting operation of the ice melting section is terminated.

[0039] In the above technical solution, the remaining time of ice melting current I at any monitoring point R Use the following formula to calculate:

[0040] ;

[0041] Where D is the outer diameter of the ground wire after ice coating, d is the outer diameter of the ground wire, g0 is the specific gravity of ice, b is the thickness of ice coating, △t is the difference between the ground wire temperature and the ambient temperature, T R Indicates the remaining time, R T0 is the equivalent ice layer conduction thermal resistance, R T1 It represents the equivalent thermal resistance of convection and radiation, and R0 represents the resistance of the ground wire at 0℃ temperature.

[0042] The present invention provides an intelligent ice melting system for ground wires of power transmission lines, wherein the power transmission lines include multiple lines, including:

[0043] The icing safety index calculation module is used to calculate the real-time icing safety of each ice-melting section based on the real-time ice thickness prediction value, tower bearing capacity, ground wire tension and cross-span distance, and hardware and insulator loads.

[0044] The ice melting sequence set generation module is used to sort all ice melting sections according to the real-time ice cover safety of each ice melting section to form an ice melting sequence set, and select the ice melting section with the highest ice melting urgency to perform the ice melting operation;

[0045] The ice melting operation module includes the following steps for any ice melting section:

[0046] Choose to execute the fastest ice melting mode or normal ice melting mode;

[0047] The fastest ice melting mode or the normal ice melting mode includes an aggressive ice melting strategy, a balanced ice melting strategy, and a conservative ice melting strategy, in which the ice melting current values ​​are distributed in descending order. The corresponding ice melting strategy is selected or the ice melting mode switching is executed according to the current ice melting current constraint condition of the ice melting section.

[0048] The present invention provides the following beneficial effects: It predicts the ice growth rate of transmission line ground wires based on historical and real-time data from online monitoring devices, thereby deriving predicted ice thickness values ​​for each ice-melting section. It also calculates the ice safety level based on real-time data from each ice-melting section, forms an ice-melting sequence, selects critical lines for ice-melting operations, distinguishes between normal and fastest modes, and implements ice-melting operations in conjunction with a dynamic ice-melting strategy. This system prioritizes ice-melting operations based on real-time ice-safety levels, ensuring that ice-melting prioritizes the lines with the highest ice-melting urgency, thereby improving resource allocation efficiency. It selects normal or fastest mode based on external instructions to adapt to different operating conditions (e.g., emergency situations or planned operations). Combining aggressive, balanced, and conservative strategies balances ice-melting speed with equipment safety, improving operational adaptability.

[0049] Furthermore, the present invention arranges monitoring points at three or more tower positions on the ground line that are most susceptible to ice accumulation and least susceptible to ice accumulation, and monitors the ambient temperature, ground line temperature, wind speed and ice thickness. By arranging monitoring points at key positions that are most susceptible to ice accumulation and least susceptible to ice accumulation, it is ensured that the data of the monitoring points can represent the overall working conditions of the line. Multi-point monitoring can obtain more comprehensive environmental and equipment status data, support more accurate current adjustment and strategy switching, and real-time monitoring provides a dynamic data basis under multiple working conditions, providing support for ice melting current and strategy adjustment.

[0050] Furthermore, when calculating the safety degree of icing, the present invention comprehensively considers the ice thickness, tower bearing capacity, ground wire tension and crossing distance, loads on hardware and insulators and their limit values, and calculates the index value in combination with weights; considers multiple factors to quantify the safety risk of each ice-melting section, avoiding the deviation that may be caused by single indicator judgment; sorting is based on comprehensive safety indicators to ensure that high-risk sections are given priority for ice melting, thereby improving overall safety; real-time index calculation supports rapid evaluation and adjustment under different working conditions, and adapts to complex operating environments.

[0051] Furthermore, the present invention only adds lines whose current ice thickness prediction reaches a set threshold within a set time to the ice-melting sequence set; excludes sections that do not meet the threshold conditions, ensuring that ice-melting resources are concentrated on urgent line sections; reduces the size of the ice-melting sequence set through pre-screening, reducing calculation and scheduling complexity; and combines ice-melting operations with prediction data to determine ice-melting routes in advance and optimize ice-melting decisions.

[0052] Furthermore, in the fastest ice-melting mode, the present invention adjusts the ice-melting current (conservative, balanced, aggressive) according to the current strategy switching logic; supports dynamic switching of different strategies to adapt to real-time changes in equipment temperature, ice-melting progress and safety constraints; through the strategy switching mechanism, it avoids equipment damage or temperature exceeding the limit due to excessive current, ensuring the safety of ice-melting operations; the aggressive strategy prioritizes the use of the equipment's maximum carrying capacity to accelerate the ice-melting process.

[0053] Furthermore, in the normal ice-melting mode, the present invention switches between conservative, balanced, and aggressive modes according to the remaining time ice-melting current adjustment strategy; in the normal mode, the current value is dynamically adjusted based on the remaining time ice-melting current to ensure that the ice-melting task is completed as planned; in the normal mode, unnecessary energy consumption is reduced by gradually reducing the current (such as the conservative ice-melting strategy); and the strategy switching mechanism is also supported to adapt to complex working conditions.

[0054] Furthermore, during the de-icing operation of any ground wire line, the present invention monitors the ground wire temperature of all monitoring points in real time and adjusts the current or strategy according to the temperature limit; through monitoring and real-time adjustment, the ground wire temperature is prevented from exceeding the design allowable value of the equipment, protecting the equipment from damage; based on real-time temperature feedback, the current or switching strategy is dynamically adjusted to improve de-icing efficiency and safety; and the degradation of the mechanical properties of the ground wire due to long-term high temperature is avoided.

[0055] Furthermore, the present invention automatically terminates the ice melting operation of a ground line when the ice thickness at all monitoring points of the line reaches the set target value; without manual intervention, the system can automatically terminate the ice melting according to the target, saving manpower; ensuring that the ice melting current is turned off in time after reaching the target, avoiding the equipment from running in a high temperature or high current state for a long time; after the ice melting operation is terminated in time, the system can transfer resources to other lines to optimize overall efficiency.

[0056] Furthermore, the present invention calculates the remaining time ice-melting current of any monitoring point based on parameters such as the outer diameter of the ice covering the ground wire and the temperature difference; accurately calculates the remaining time ice-melting current based on thermodynamic and electrical models to ensure that the ice-melting current value is reasonable; through the remaining time current control, it is ensured that neither time is wasted nor equipment damage is caused; considering real-time parameters such as the outer diameter of the ice covering and temperature, it adapts to various operating conditions and improves the ice-melting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1Schematic diagram of the method flow of the present invention;

[0058] Figure 2 This is a flow chart of the ice melting strategy switching of the present invention;

[0059] Figure 3 A software application interface a for a specific embodiment;

[0060] Figure 4 The software application interface b of the specific embodiment;

[0061] Figure 5 This is the software application interface c of a specific embodiment. DETAILED DESCRIPTION

[0062] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but they do not constitute a limitation to the present invention.

[0063] Example 1

[0064] like Figure 1 As shown, the present invention provides an intelligent de-icing method specifically for ground wires in power transmission lines. Ground wires in transmission lines not only perform important functions such as lightning protection and shielding, but also significantly impact system safety in icing environments. Therefore, all de-icing steps in the present invention are designed specifically for the actual operating conditions of ground wires. Specifically, the steps include:

[0065] 1. Ice thickness prediction

[0066] Based on the historical and real-time data collected by the online monitoring device, the ice coverage growth rate of the transmission line ground wire is predicted to obtain the estimated ice thickness value of each ice melting section.

[0067] 2. Real-time icing safety calculation

[0068] The real-time ice thickness prediction value of each ice-melting section is used, combined with key parameters such as tower bearing capacity, ground conductor tension, cross-span distance, and load on hardware and insulators, to calculate the real-time ice safety of each ice-melting section, focusing on evaluating the safe operation of the ground wire under ice-covered conditions.

[0069] 3. Formation and selection of ice-melting sequences

[0070] All ground line ice-melting sections are sorted according to the real-time ice safety to form an ice-melting sequence set, and the section with the lowest safety (i.e., the highest ice-melting urgency) is selected for ice-melting operation according to the preset urgency number.

[0071] 4. Intelligent ice-melting current control and strategy switching

[0072] During the ice-melting process, the system intelligently regulates the melting current based on real-time monitoring data, selecting either the fastest or normal melting mode based on external commands. In both the fastest and normal modes, the melting current values ​​are distributed sequentially from small to large, with aggressive, balanced, and conservative melting strategies automatically switching based on the current ground line melting requirements, ensuring efficient and safe operation.

[0073] De-icing sections are defined as the division of the entire transmission line into several continuous, independent operating units with similar operating conditions, based on the line's geographic environment, structural characteristics, and real-time monitoring data (such as ice thickness, tower bearing capacity, ground conductor tension, cross-span distance, and hardware and insulator loads). Each de-icing section is treated as an independent unit for safety assessment and de-icing operations, enabling precise, dynamic, and targeted ice removal to ensure safe and stable line operation.

[0074] The principle of the present invention is further explained below with reference to specific embodiments.

[0075] This embodiment uses a machine learning model to predict transmission line icing based on historical and real-time data from online monitoring devices. This embodiment employs the technical solution described in patent application number 202311669638X, entitled "Method and System for Predicting Overhead Line Icing Thickness," to predict transmission line ground wire icing.

[0076] Based on the characteristics of transmission lines, this embodiment constructs a hierarchical model for evaluating the safety of transmission line icing, aiming to systematically evaluate the impact of various factors on the overall safety of the line.

[0077] The target layer of the hierarchical model is the ice safety assessment of transmission lines, the criterion layer is the ice thickness, towers, ground wires, hardware and insulators, and the solution layer is the towers used for assessment corresponding to each section of the line.

[0078] The primary evaluation objective is the icing safety of transmission lines. This is the highest level of the hierarchical model and represents the ultimate decision-making objective. The criterion level, below the objective level, includes several key factors that significantly impact the icing safety of transmission lines. The scenario level, building upon the criterion level, lists the specific scenarios to be evaluated, namely, the towers for each transmission line. Each tower represents a specific decision-making option that requires comparison during the evaluation. Based on the objectives, criteria, and scenarios identified above, a hierarchical diagram is drawn to clearly demonstrate the relationships between the various levels.

[0079] Specifically, the security indicators set in this embodiment are as follows:

[0080] 1. Ice thickness index I 覆冰This indicator assesses the ratio of the current predicted ice thickness to the designed ice thickness, reflecting the relative degree of ice load on the line. This ratio indicates that the ice thickness within a specified timeframe will reach or exceed the designed value, placing the line at a higher risk. This indicator directly reflects the future extent of ice accumulation on the line and can quickly indicate the urgency of ice melting needs.

[0081] 2. Tower bearing capacity index: Evaluate the bearing capacity of towers under icing and specific working conditions (such as accident, normal, and uneven icing conditions) to ensure their structural safety.

[0082] ① Accident (line break) condition

[0083] The pole tower is checked according to the load conditions of static load (horizontal and vertical load), tension and wire break tension difference under different ice thickness conditions. The ice area is determined according to the change of ice thickness. The load combination coefficient of wire break condition is considered as 0.9 to determine the minimum ice thickness at which the pole tower exceeds the bearing capacity.

[0084] ;

[0085] Among them, N 杆塔 Indicates the current force on the tower, N 极限,断线 Indicates the ultimate bearing capacity of the tower under line break conditions.

[0086] ②Uneven icing conditions

[0087] The tower is checked according to the static load (horizontal and vertical load) and tension of the tower under different ice thickness conditions and the load conditions of unbalanced tension under uneven icing conditions. The ice area is determined according to the change of ice thickness. The load combination coefficient of uneven icing conditions is considered as 0.9 to determine the minimum ice thickness at which the tower exceeds the bearing capacity.

[0088] ;

[0089] Among them, N 极限,不均匀 It indicates the ultimate bearing capacity of the tower under uneven working conditions.

[0090] ③ Under normal icing conditions

[0091] The pole tower is checked according to the load conditions of the static load (horizontal and vertical load) of the tower under different ice thickness conditions, tension and actual span, and tension difference under terrain conditions. The ice area is determined according to the change of ice thickness. The load combination coefficient of the icing condition is considered as 1.0 to determine the minimum ice thickness at which the pole tower exceeds the bearing capacity.

[0092] a. When calculating the excess load of the ground wire support and the main / diagonal materials of the tower, the structural importance coefficient shall be considered as 1.0.

[0093] b. The ice area shall be determined according to the ice thickness based on the principle of height. For example, if the ice thickness is 12mm, it shall be considered as Class I 15mm ice area. The combination of disconnection conditions, uneven ice conditions and calculation parameters related to the ice area shall be determined and calculated according to the corresponding regulations and specifications for different ice areas.

[0094] ;

[0095] Among them, N 极限,正常 Indicates the ultimate bearing capacity of the tower under normal working conditions.

[0096] Comprehensive tower bearing capacity index value: I 杆塔 =max(I 杆塔,断线 ,I 杆塔,不均匀 , I杆塔,正常 )

[0097] Ground wire tension and cross-span distance indicators: Evaluate whether the tension and cross-span distance of the ground wire under icing conditions meet safety requirements.

[0098] ① Ground wire tension verification index: 90% of the designed breaking force of the ground wire (rated breaking force * 95%) is taken as the excessive tension of the ground wire caused by icing, and the ground wire tension is evaluated whether it exceeds the limit under icing conditions.

[0099] ;

[0100] Among them, I 张力 Indicates the ground wire tension calibration index;

[0101] T 当前 Indicates the current tension of the ground conductor under ice conditions;

[0102] T 极限 Indicates the maximum allowable tension of the ground wire, which is defined as 90% of the designed breaking force. 张力 ≥1 indicates that the ground wire tension exceeds the limit requirement. This indicator is used to determine whether icing causes the tension to exceed the limit and to check the safety of the line.

[0103] ② Insufficient crossing distance index: Considering the entire line to be evenly covered with ice, the sag under high temperature sag is calculated under icing conditions as the limit crossing verification condition for insufficient crossing distance, and evaluate whether the ground wire meets the crossing safety requirements under high temperature icing sag conditions.

[0104] ;

[0105] Among them, I 交跨 Indicates insufficient crossover distance indicator;

[0106] H high temperature sag refers to the high temperature sag of the ground conductor under ice cover;

[0107] H 极限 Indicates the maximum distance between the conductor and the ground or the crossover.

[0108] When I 交跨 ≥1 indicates that the crossing distance is insufficient, which may pose a line safety risk. This indicator is used to assess whether the ground wire has excessive sag due to ice coverage, affecting the safety of the line crossing area or ground equipment.

[0109] Hardware load index I 金具 : Evaluate whether the load on hardware under icing conditions exceeds its design limit.

[0110] ;

[0111] L 当前 Indicates real-time hardware load;

[0112] L 极限 Indicates 90% of the rated breaking load of the hardware.

[0113] The hardware load index directly reflects the mechanical load risk caused by icing. 金具 When ≥1, the hardware is at risk of damage.

[0114] Insulator load index: Evaluate whether the load on the insulator under icing conditions exceeds its design limit:

[0115] ;

[0116] L 当前 Indicates real-time insulator load;

[0117] L 极限 Indicates 90% of the rated breaking load of the insulator. Similar to the hardware index, the insulator load index is used to judge its mechanical safety. 绝缘子 When ≥1, there is a greater risk of damage to the insulator.

[0118] For each pair of factors at the criterion and solution levels, a pairwise comparison is performed to form a comparative judgment matrix. Decision-makers are required to fill in the relative weights in the comparison matrix based on their subjective judgment and professional knowledge. This step quantifies the importance of different factors and provides a data foundation for subsequent calculations. Through brainstorming and expert scoring, a judgment matrix at the criterion level is generated. B1-B5 represent the five evaluation indicators mentioned above, as shown in Table 1:

[0119] Table 1 Judgment Matrix

[0120] A B1 B2 B3 B4 B5 B1 1 3 5 7 7 B2 1 / 3 1 2 3 3 B3 1 / 5 1 / 2 1 2 2 B4 1 / 7 1 / 3 1 / 2 1 1 B5 1 / 7 1 / 3 1 / 2 1 1

[0121] The judgment matrix of the criterion layer is normalized by columns, and the normalized matrix of the criterion layer judgment matrix is ​​shown in Table 2.

[0122] Table 2 Normalized matrix of criterion layer judgment matrix

[0123] A B1 B2 B3 B4 B5 B1 0.54973822 0.580645 0.555556 0.5 0.5 B2 0.183246073 0.193548 0.222222 0.214286 0.214286 B3 0.109947644 0.096774 0.111111 0.142857 0.142857 B4 0.078534031 0.064516 0.055556 0.071429 0.071429 B5 0.078534031 0.064516 0.055556 0.071429 0.071429

[0124] Calculate the row sum and then normalize the columns to obtain the weight vector (eigenvector) shown in Table 3.

[0125] Table 3 Eigenvector table

[0126] A Matrix after row sum Eigenvector B1 2.685938937 0.537188 B2 1.027588111 0.205518 B3 0.603547234 0.120709 B4 0.341462859 0.068293 B5 0.341462859 0.068293

[0127] The weight vector (eigenvector) w is: (0.537, 0.206, 0.121, 0.068, 0.068) T , reflecting the importance of each factor relative to the goal in the criterion layer.

[0128] Multiplying the judgment matrix A by the eigenvector w yields:

[0129] Aw=(2.713, 1.036, 0.604, 0.342, 0.342) T

[0130] Since Aw=λ max w, the maximum characteristic root can be calculated:

[0131] λ max =(2.713 / 0.537188,1.036 / 0.205518,0.604 / 0.120709,0.342 / 0.068293,0.342 / 0.068293) / 5=5.023

[0132] In order to avoid interference from other factors on the judgment matrix, the hierarchical analysis method needs to perform consistency test on the judgment matrix. The so-called consistency test refers to determining the allowable range of inconsistency of A. Among them, the only non-zero characteristic root of the n-order consistent matrix is ​​n, and the maximum characteristic root λ of the n-order positive reciprocal matrix A is max ≥n, if and only if λ max =n, A is a consistent matrix. Since λ max Continuously dependent on a ij , then λ max The greater the value is than n, the more serious the inconsistency of A is. The consistency index is calculated using CI. The smaller the CI is, the greater the consistency is. The eigenvector corresponding to the maximum eigenvalue is used as the weight vector of the influence of the compared factor on a certain factor in the upper layer. The greater the inconsistency, the greater the judgment error caused. Therefore, we can use λ max -n value is used to measure the inconsistency of A.

[0133] ;

[0134] CR<0.1, the judgment matrix of the criterion layer passes the consistency test, indicating that the consistency of the judgment matrix A is considered to be within the allowable range. At this time, the eigenvector of A can be used to perform weight vector calculation.

[0135] In summary, the weight coefficients of each risk factor are calculated and shown in Table 4.

[0136] Table 4 Risk factor weights

[0137]

[0138] The comprehensive weight of ice thickness is 53.7%, which is the most important risk factor; the comprehensive weights of poles and ground wires are both over 10%, which are the second most important risk factors; the comprehensive weights of hardware and insulators are both less than 10%, which are general risk factors.

[0139] In order to build a unified safety evaluation system, it is recommended to consider the load ratio of each influencing factor to the design boundary conditions or the ultimate load capacity of the equipment as a sub-indicator of the evaluation, as shown in Table 5:

[0140] Table 5 Risk factors

[0141]

[0142] When evaluating the safety index of a single ice-melting section, multiple monitoring points with relatively severe operating conditions should be selected for safety assessment. The calculation formula for the ice safety index of a single ice-melting section is as follows:

[0143] ;

[0144] Where S is the ice safety index of a single ice melting section; i is the i-th monitoring point in a single ice melting section; k I is the line importance coefficient. For example, it can be 1.25 for UHV lines and 1.0 for EHV lines. The ice safety index score can be used to quantify the risk. A higher overall score indicates a greater urgency for ice melting, taking into account all five indicators.

[0145] Risk factors at each monitoring point should match. For example, with the tower as the center, the ground wire should be the common ground wire or OPGW on the front and rear sides of the tower, the hardware and insulators should be the ground wire string on the tower being studied, and the ice coverage value should be the value monitored or estimated at the tower location or front and rear sides.

[0146] The order of melting ice on the ground wires in this embodiment comprehensively considers the development of ice coverage and the urgency of ice melting on multiple lines.

[0147] First, based on the predicted ice development of the line, known as the ice safety index, the line is added to the ground line melting sequence. Within the melting sequence, the urgency of ice melting for multiple sections, known as the ice safety index scores, is determined. These sections are ranked from highest to lowest according to the ice safety index scores, and the melting sequence is determined. A preset number of lines with the highest rankings are selected for melting. The melting sequence and order change in real time, and the corresponding melting current also changes.

[0148] Taking into account the decision-making process for ice melting and the time required for ground line ice melting, we recommend that the threshold for adding a line to the ice melting sequence set be the ice thickness reaching the design ice thickness within 5 hours. The ice melting sequence set is dynamically adjusted based on the ice coverage forecast for ice-melting lines.

[0149] In this embodiment, the fastest ice-melting mode calculates the maximum and minimum ice-melting currents according to the "Technical Specification for the Design of DC Ice-Melting Systems" (DL / T 5511-2016). The ice-melting current should be selected between the minimum and maximum ice-melting currents, taking into account the melting time. If the ice-melting current is less than the minimum, ice-melting will be ineffective. If the ice-melting current is greater than the maximum, the ground wire will be permanently deformed, causing increased sag or compromising its mechanical strength.

[0150] The minimum ice-melting current refers to the minimum current required to melt the ice on the ground wire under the corresponding ambient temperature and wind speed conditions. The actual ice-melting current should be greater than the minimum ice-melting current.

[0151] The minimum ice melting current is calculated using the Boorsdale formula:

[0152] ;

[0153] Where: I min ——Minimum ice melting current (A);

[0154] △t——the difference between the ground wire temperature and the ambient temperature (℃). When the icing environment temperature is -5℃ and the ground wire non-icing temperature is 2℃, △t is 7℃;

[0155] R T0 ——Equivalent ice layer thermal conductivity (℃·cm / W);

[0156] R T1 ——Equivalent thermal resistance of convection and radiation (℃·cm / W);

[0157] R0——the resistance of the ground wire at 0℃ (Ω / m), R0= R 20 (1-20α), where R 20is the resistance of the ground wire at 20°C (Ω / m); α is the resistance temperature coefficient of the ground wire (1 / °C), which is 0.00403 for aluminum stranded wire and steel-core aluminum stranded wire, 0.00347 for aluminum alloy stranded wire and steel-core aluminum alloy stranded wire, 0.00366 for aluminum-clad steel stranded wire, and 0.0046 for galvanized steel stranded wire;

[0158] D — outer diameter of the ground wire after ice coating (cm);

[0159] d——outer diameter of the ground wire (cm);

[0160] λ b -- Thermal conductivity of ice [W / (℃·cm)], 0.0227 for rime and 0.0012 for rime;

[0161] V——wind speed during ice melting (m / s), take 3m / s~5m / s.

[0162] For lines that are not fully iced, or where ice distribution in the ice-melting section is uneven, the maximum ice-melting current of the ground wire can be calculated as follows:

[0163] ;

[0164] Where: I max ——maximum ice melting current (A);

[0165] W R ——Radiated heat dissipation power of the ground wire (W / m);

[0166] W F ——Convection heat dissipation power of the ground wire (W / m);

[0167] W S ——Sunlight absorption power of the ground wire (W / m);

[0168] R m ——Resistance of the ground wire at the allowable temperature (Ω / m);

[0169] E 1——Radiation coefficient of ground wire surface, preferably 0.9;

[0170] S 1——Stefan-Boltzmann constant, taken as 5.67×10 -8 (W / m 2 );

[0171] D 1——Outer diameter of the ground wire (m);

[0172] t m ——allowable temperature of ground wire (℃);

[0173] t ——Ambient temperature (℃), preferably 10℃~15℃;

[0174] λ f ——ground surface air heat transfer coefficient [W / (m·℃)];

[0175] R e ——Reynolds number;

[0176] α s ——The ground surface heat absorption coefficient should be 0.9;

[0177] J s ——The sunlight intensity on the ground line should be 900W / m 2 .

[0178] For fully ice-covered lines, the maximum ice-melting current of the ground wire can be calculated as follows:

[0179] ;

[0180] Where: ε n - Ice layer emissivity coefficient: 0.64 for rime and 0.32 for rime;

[0181] t ——Ambient air temperature (℃): preferably -3℃~-5℃.

[0182] When calculating the maximum ice melting current, the allowable temperature of the ground wire should comply with the requirements of Table 6:

[0183] Table 6 Allowable temperature values ​​for different types of ground wires

[0184]

[0185] The magnitude of the DC ice-melting voltage is mainly related to the ground resistance and the ice-melting current, and the relationship is linear. If the internal resistance of the ice-melting device is ignored and the ground impedance to ground is infinite, it can be seen that the ice-melting voltage and ice-melting current follow Ampere's law. The ice-melting voltage is calculated as follows:

[0186] ;

[0187] Where: U R ——ice melting voltage (kV);

[0188] P——ice melting capacity (kV);

[0189] I R ——actual ice melting current (kA);

[0190] R 20- Resistance of the conductor or ground wire in the ice melting circuit at 20°C (Ω / km);

[0191] L ——ground line length (km);

[0192] n ——Number of split roots.

[0193] Given the ice melting current, the formula for calculating the ice melting time is as follows:

[0194] ;

[0195] Where: T R ——melting time (h);

[0196] g0——Specific gravity of ice (g / cm3), 0.9 for rime and 0.3 for rime;

[0197] b ——Ice cover thickness (cm).

[0198] In this embodiment, for each ice melting section, three or more tower positions that are most susceptible to ice accumulation and least susceptible to ice accumulation are equipped with ice accumulation online monitoring devices to monitor data such as ambient temperature, ground temperature, wind speed, and ice accumulation thickness. The parameter is named t Hi , t Di 、v Hi 、D Hi (i is the i-th monitoring device).

[0199] Since the present embodiment can set the ice melting time according to the external instruction, during the ice melting operation, the remaining time of ice melting current I R Use the following formula to calculate:

[0200] ;

[0201] Where D is the outer diameter of the ground wire after ice coating, d is the outer diameter of the ground wire, g0 is the specific gravity of ice, b is the thickness of ice coating, △t is the difference between the ground wire temperature and the ambient temperature, T R Indicates the remaining time, R T0 is the equivalent ice layer conduction thermal resistance, R T1 It represents the equivalent thermal resistance of convection and radiation, and R0 represents the resistance of the ground wire at 0℃ temperature.

[0202] After starting ice melting, the ice melting current is calculated based on the monitoring data of the section prone to ice accumulation. It is verified whether the ice melting current is within the limit (the current carrying capacity of the ground wire in the section not prone to ice accumulation) and whether the ground wire temperature is within the limit. The ice melting current is adjusted according to a fixed time step. When the monitored ice thickness is less than the target value, the ice melting ends.

[0203] like Figure 2 As shown in the figure, the real-time control strategy of ice melting current is as follows:

[0204] (1) Real-time calculation of ice melting current

[0205] According to the online monitoring data of all monitoring points in the ice melting section currently performing ice melting operation, the ice melting current of the i-th monitoring point at m hours is calculated to obtain I hi ; Calculate the minimum ice melting current and get I mini ; Calculate the maximum ice melting current for full ice coverage and obtain I Qmaxi ; Calculate the maximum ice melting current for non-full ice coverage and obtain I FQmaxi If the ice coverage value of the monitoring point is greater than 0, the maximum ice melting current of partial ice coverage will not be calculated.

[0206] Users can choose the fastest ice melting mode or the m-hour ice melting mode (i.e. normal ice melting mode) according to their needs. In different ice melting modes, different ice melting strategies can be selected according to their needs:

[0207] 1) Fastest ice melting mode

[0208] a. Radical Ice-Breaking Strategy

[0209] According to the online monitoring data, the minimum ice melting current (MIN{I mini}), the maximum value of the maximum full ice melting current (MAX{ I Qmaxi}), the minimum value of the maximum non-full ice melting current (MIN{I FQmaxi}), take MAX{ I Qmaxi} and MIN{I FQmaxi} is used as the ice melting current, which should be greater than MIN{I mini}, otherwise the allowed ice-melting current is less than the minimum ice-melting current and ice melting cannot be completed.

[0210] b. Balanced Ice-Thaw Strategy

[0211] According to the online monitoring data, the minimum ice melting current (MIN{I mini}), the average value of the maximum full ice melting current (AVERAGE{I Qmaxi}), the minimum value of the maximum non-full ice melting current (MIN{I FQmaxi}), take AVERAGE{ I Qmaxi} and MIN{ I FQmaxi} is used as the ice melting current, which should be greater than MIN{I mini Otherwise, it will prompt that the current strategy cannot be used to melt the ice, and the system will automatically jump to the aggressive strategy for judgment.

[0212] c. Conservative mode

[0213] According to the online monitoring data, the minimum ice melting current (MIN{I mini}), the minimum value of the maximum full ice melting current (MIN{ I Qmaxi}), the minimum value of the maximum non-full ice melting current (MIN{I FQmaxi}), take MIN{ I Qmaxi} and MIN{I FQmaxi} is used as the ice melting current, which should be greater than MIN{I mini}, otherwise it will prompt that the ice cannot be melted under the current strategy, and the system will automatically jump to the equilibrium strategy for judgment.

[0214] 2) M-hour ice melting mode

[0215] a. Radical Ice-Breaking Strategy

[0216] According to the online monitoring data, the minimum ice melting current (MIN{I mini}), (m-melting time) hours of maximum value of ice melting current (MAX{I hi}), the minimum value of the maximum non-full ice melting current (MIN{I FQmaxi}), take MAX{I hi} and MIN{ I FQmaxi} is used as the ice melting current, which should be greater than MIN{I mini Otherwise, the allowed ice-melting current is less than the minimum ice-melting current, and ice-melting cannot be completed in m hours. The system will automatically switch to the fastest ice-melting mode.

[0217] b. Balanced Ice-Thaw Strategy

[0218] According to the online monitoring data, the minimum ice melting current (MIN{I mini}), average value of ice-melting current (m-melting time) hours (AVERAGE{I hi}), the minimum value of the maximum non-full ice melting current (MIN{ I FQmaxi}), take AVERAGE{I hi} and MIN{ I FQmaxi} is used as the ice melting current, which should be greater than MIN{I mini Otherwise, it will prompt that the current strategy cannot be used to melt the ice, and the system will automatically jump to the aggressive strategy for judgment.

[0219] c. Conservative mode

[0220] According to the online monitoring data, the minimum ice melting current (MIN{I mini}), (m-melting time) hours of minimum value of ice melting current (MIN{I hi}), the minimum value of the maximum non-full ice melting current (MIN{I FQmaxi}), take MIN{I hi} and MIN{ I FQmaxi} is used as the ice melting current, which should be greater than MIN{I mini}, otherwise it will prompt that the ice cannot be melted under the current strategy, and the system will automatically jump to the equilibrium strategy for judgment.

[0221] (2) Monitoring ground wire temperature

[0222] Check the ground temperature t of all monitoring points Di Is it less than the ground wire operation problem t m If yes, the check passes; if not, a prompt message will be given: "The ground wire temperature exceeds the allowable temperature. It is recommended to cancel the ice melting of this line or reduce the ice melting current." If the ground wire temperature exceeds the allowable temperature value, the ice melting current adjustment method will no longer be implemented according to the set strategy in the fastest ice melting mode or the normal ice melting mode. The following methods can be used:

[0223] In normal mode, if the temperature exceeds the limit, adjust the current ice melting current to I R ', preferably by extending the remaining ice melting time:

[0224] ;

[0225] Among them, T 允许 Indicates the allowable value of ground wire temperature, T 当前 Indicates the current value of the ground wire temperature.

[0226] In the fastest mode, the current is adjusted based on the current ice melting current by decreasing the set ratio.

[0227] (3) Monitoring ice thickness

[0228] According to a fixed time step (such as 30s, which can be set), the ice melting current in the selected mode is calculated based on the real-time data of the line, the ice melting current is adjusted in real time, and the ice thickness is monitored.

[0229] Set the target ice thickness value D MB , if D Hi Both are smaller than D MB , the ice melting section is completed, and a prompt message "Ice melting completed" is given.

[0230] Based on the above rules, real-time ground wire de-icing current control software was developed in C#. The software uses meteorological data such as ambient temperature, ground wire temperature, wind speed, and ice thickness monitored on the transmission line, as well as ground wire parameters, as input. It controls the de-icing current pattern in real time, displaying the ground wire de-icing status, meteorological conditions, and line icing conditions.

[0231] The main interface of the ground wire ice melting current control software is as follows: Figure 3 shown.

[0232] The software can display real-time external parameters such as ambient temperature, wind speed, ice thickness, etc. at different monitoring points, calculate the minimum ice melting current, maximum non-fully covered ice melting current, maximum fully covered ice melting current, timed ice melting current, etc. at each monitoring point, and has a built-in algorithm that automatically selects the ice melting current for the line based on the ice melting mode and strategy.

[0233] The software can set and modify the line ground wire parameters and ice melting current calculation parameters. The software can set and modify the line ground wire parameters and ice melting current calculation parameters, such as Figure 4 The software can set the ice melting mode and strategy, and specify the ice melting calculation interval. If the current ice melting mode and strategy cannot meet the requirements, the software can automatically jump to a more suitable ice melting mode and strategy and give a prompt, such as Figure 5 shown.

[0234] Example 2

[0235] The present invention provides an intelligent ice melting system for ground wires of power transmission lines, wherein the power transmission lines include multiple lines, including:

[0236] The icing safety index calculation module is used to calculate the real-time icing safety of each line section based on the real-time ice thickness prediction value, tower bearing capacity, ground wire tension and cross-span distance, and hardware and insulator loads.

[0237] The ice melting sequence set generation module is used to sort all lines according to the real-time ice safety of each line to form an ice melting sequence set;

[0238] The de-icing operation module is used to select a preset number of lines with the highest de-icing urgency according to the de-icing sequence set to perform de-icing operations. The de-icing process for any line includes:

[0239] Choose to execute the fastest ice melting mode or normal ice melting mode;

[0240] The fastest ice melting mode or the normal ice melting mode includes an aggressive ice melting strategy, a balanced ice melting strategy, and a conservative ice melting strategy, in which the ice melting current values ​​are distributed in descending order. The corresponding ice melting strategy is selected or the ice melting mode switching is executed according to the current ice melting current constraint condition of the line.

[0241] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

Claims

1. A method for intelligently melting ice on a ground line of a power transmission line, wherein the power transmission line comprises multiple lines, characterized in that: The following steps are involved: Calculate the real-time ice safety of each de-icing section based on the real-time ice thickness prediction value, tower bearing capacity, ground wire tension and cross-span distance, and hardware and insulator loads. All ice-melting sections are sorted according to their real-time ice-covering safety to form an ice-melting sequence set. The ice-melting section with the highest ice-melting urgency is selected according to the ice-melting sequence set to perform the ice-melting operation: Selecting the fastest ice-melting mode or the normal ice-melting mode according to external instructions. Both the fastest ice-melting mode and the normal ice-melting mode include an aggressive ice-melting strategy, a balanced ice-melting strategy, and a conservative ice-melting strategy, where the ice-melting current values ​​are distributed in descending order from roughly small to large. Switching to the corresponding ice-melting mode or ice-melting strategy is based on the current ice-melting constraints of the ice-melting section; and adjusting the ice-melting current according to the monitoring data of the ice-melting section. The ice melting strategy switching process in the fastest ice melting mode includes: Prioritize the conservative ice-melting strategy: The smaller value of the minimum of the maximum fully covered ice-melting current and the minimum of the maximum partially covered ice-melting current at all monitoring points is taken as the ice-melting current. This ice-melting current should be greater than the minimum of the minimum ice-melting currents at all monitoring points. Otherwise, the strategy switches to the balanced strategy. Balanced ice melting strategy: The smaller of the average of the maximum fully covered ice melting current and the maximum partially covered ice melting current at all monitoring points is used as the ice melting current. This ice melting current must be greater than the minimum of the minimum ice melting currents at all monitoring points. Otherwise, the strategy switches to the aggressive strategy. Aggressive strategy: The smaller value of the maximum value of the maximum fully covered ice melting current and the minimum value of the maximum partially covered ice melting current at all monitoring points is taken as the ice melting current. This ice melting current should be greater than the minimum value of the minimum ice melting current at all monitoring points, otherwise it will be prompted that ice melting cannot be completed.

2. The method according to claim 1, wherein: Monitoring points are set up at several tower positions that are most susceptible to ice accumulation and least susceptible to ice accumulation in each ice-melting section to monitor ambient temperature, ground temperature, wind speed and ice thickness.

3. The method according to claim 1, wherein: The calculation process of the current ice safety degree of any ice melting section includes: The analytic hierarchy process is used to calculate the risk weight coefficients of ice thickness, towers, ground wires, hardware and insulators; Calculate the ratio of the current predicted ice thickness value to its limit value, the ratio of the tower bearing capacity to its limit value, the ratio of the ground wire tension and cross-span distance to its limit value, the ratio of the hardware load to its limit value, and the ratio of the insulator load to its limit value for each monitoring point in the ice melting section; According to the maximum value of each ratio and the corresponding weight, the ice safety index of the ice melting section is calculated.

4. The method according to claim 1, wherein: Only the ice melting sections whose current ice thickness prediction value reaches the set threshold within the set time are added to the ice melting sequence set.

5. The method according to claim 4, characterized in that: The ice melting strategy switching process in the normal ice melting mode includes: firstly executing the conservative ice melting strategy: taking the smaller value of the minimum value of the remaining time ice melting current of all monitoring points and the minimum value of the maximum non-full ice melting current as the ice melting current; the ice melting current should be greater than the minimum value of the minimum ice melting current of all monitoring points, otherwise jumping to the balanced strategy; Balanced ice melting strategy: The smaller of the average of the remaining time ice melting currents of all monitoring points and the maximum non-full ice melting current is used as the ice melting current. This ice melting current must be greater than the minimum of the minimum ice melting currents of all monitoring points. Otherwise, the strategy switches to the aggressive strategy. Aggressive strategy: The smaller value of the maximum value of the remaining time melting current of all monitoring points and the minimum value of the maximum non-full ice melting current is taken as the melting current; this melting current should be greater than the minimum value of the minimum melting current of all monitoring points, otherwise it jumps to the fastest melting mode.

6. The method according to claim 4, characterized in that: The ice-melting operation process of any ice-melting section includes: all monitoring points in the ice-melting section detect in real time whether the ground wire temperature is less than the set limit; if so, the ice-melting section continues to perform ice-melting operations according to the ice-melting current of the current strategy; otherwise, the ice-melting current is reduced under the current strategy.

7. The method according to claim 1, wherein: The ice melting operation process of any ice melting section further includes: when the ice thickness of all monitoring points in the ice melting section reaches a set target value, the ice melting operation of the ice melting section is terminated.

8. The method according to claim 1, wherein: The remaining time for ice melting current I at any monitoring point R Use the following formula to calculate: Where D is the outer diameter of the ground wire after ice coating, d is the outer diameter of the ground wire, g0 is the specific gravity of ice, b is the thickness of ice coating, △t is the difference between the ground wire temperature and the ambient temperature, T R Indicates the remaining time, R T0 is the equivalent ice layer conduction thermal resistance, R T1 It represents the equivalent thermal resistance of convection and radiation, and R0 represents the resistance of the ground wire at 0℃ temperature.

9. An intelligent ice melting system for ground wires of power transmission lines, wherein the power transmission lines include multiple lines, characterized in that: For implementing the method according to any one of claims 1 to 8, comprising: The icing safety index calculation module is used to calculate the real-time icing safety of each ice-melting section based on the real-time ice thickness prediction value, tower bearing capacity, ground wire tension and cross-span distance, and hardware and insulator loads. The ice melting sequence set generation module is used to sort all lines according to the real-time ice safety of each ice melting section to form an ice melting sequence set, and select the ice melting section with the highest ice melting urgency to perform the ice melting operation; The ice melting operation module includes the following steps for any ice melting section: Choose to execute the fastest ice melting mode or normal ice melting mode; The fastest ice melting mode or the normal ice melting mode includes an aggressive ice melting strategy, a balanced ice melting strategy, and a conservative ice melting strategy, in which the ice melting current values ​​are distributed in descending order. The corresponding ice melting strategy is selected or the ice melting mode switching is executed according to the current ice melting current constraint condition of the ice melting section.

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