An ultra-high voltage ground wire ice melting control method and system based on wide-width on-load voltage regulating transformer

Abstract

The application discloses a kind of based on wide load voltage regulation variable ultra-high voltage ground wire ice-melting control method and system, comprising the following steps: S1.Based on wire type and infrared temperature measurement, obtain and calculate OPGW initial parameter;S2.According to OPGW initial parameter, calculate ice-melting current;S3.Introduce real-time wind speed, ice-melting current is corrected by introducing ice-melting form, line type as constraint condition, obtain optimal ice-melting current;S4.Based on optimal ice-melting current, dynamic voltage regulation and dynamic adjustment ice-melting current, complete line ice-melting.The method of the application is safe controllable, dynamic optimization and efficient operation to ultra-high voltage OPGW ice-melting process, provides new technical path and equipment foundation for power grid winter anti-icing power protection.

Description

Technical Field

[0001] This invention belongs to the field of line de-icing technology, specifically relating to a method and system for de-icing control of ultra-high voltage ground lines based on wide-range on-load tap changers. Background Technology

[0002] In high-altitude, mountainous, and heavy icing areas, ultra-high-voltage (UHV) transmission lines are highly susceptible to severe icing problems during winter operation. Icing significantly increases the self-weight and wind load of conductors and ground wires, leading to a substantial increase in mechanical stress on the lines. This can result in serious accidents such as line breaks, galloping, and tower collapses, threatening the safe and stable operation of the power grid. Unlike phase conductors, UHV lines typically use fiber optic composite overhead ground wires (OPGW) structures, which combine lightning protection, grounding, and communication channel functions. OPGWs contain optical fibers, making them extremely sensitive to overheating, current surges, and long-term thermomechanical stress. During de-icing operations, excessive de-icing current can cause OPGW overheating, annealing, strength reduction, or even strand breakage, leading to communication channel failure. Insufficient de-icing current, on the other hand, prevents timely ice removal, missing the critical window for emergency response. Therefore, the safety control requirements for current, temperature, and de-icing rate during OPGW de-icing are significantly higher than those for phase conductors.

[0003] Existing ground wire de-icing technologies mainly fall into the following categories: One is constant current DC de-icing, which uses a rectified power supply to output a fixed current for de-icing. However, this method has a crude adjustment mechanism and cannot adaptively adjust to different ice thicknesses, conductor temperatures, and wind speeds, making it difficult to guarantee both de-icing efficiency and safety. Another category is thyristor-controlled rectification, which has a certain current regulation capability, but its system structure is complex, with a large number of components, high control system cost, and high harmonic content. Furthermore, mobile de-icing devices suffer from large size, complex maintenance, and poor economic efficiency. In addition, most existing de-icing devices lack a dynamic adjustment mechanism based on line ice thickness, actual OPGW temperature, or its safety margin. In actual operation, the de-icing current often fails to change in a timely manner: when the ice is thick, the de-icing current is too small, resulting in low de-icing efficiency; when the ice is thin or environmental conditions improve, the de-icing current is too large, potentially causing OPGW overheating damage. These de-icing methods, lacking an effective closed-loop system, struggle to balance safety and de-icing speed.

[0004] Therefore, developing a controllable de-icing technology system for UHV OPGW ground wires has become a critical technical challenge in the current power grid de-icing field. This technology must be able to achieve continuous, stable, and rapid adjustment of the de-icing current with the support of a wide-range adjustable DC power supply. It must also be able to construct closed-loop control logic based on monitorable parameters such as line ice thickness, enabling dynamic adjustment of the de-icing current within a safe range. While ensuring that the OPGW does not experience over-temperature, annealing, or strength degradation, it should accurately output the optimal de-icing current to meet different icing conditions, thereby avoiding the coexistence of over-melting and under-melting problems in traditional de-icing methods and achieving a balance between de-icing efficiency, equipment safety, and engineering economics. Summary of the Invention

[0005] To address the shortcomings of existing technologies, one of the objectives of this invention is to provide a method for controlling ice melting of ultra-high voltage ground wires based on wide-range on-load tap changers, so as to achieve safe, controllable, dynamically optimized, and efficient operation of the ice melting process of ultra-high voltage OPGW, and to provide a new technical path and equipment foundation for power grid winter ice prevention and power supply.

[0006] The second objective of this invention is to provide a system for implementing the aforementioned UHV ground wire de-icing control method based on a wide-range on-load tap changer.

[0007] This invention provides a method for controlling ice melting on ultra-high voltage ground wires based on wide-range on-load tap-changing transformers, comprising the following steps:

[0008] S1. Based on the conductor type and infrared thermometry, obtain and calculate the initial parameters of the OPGW;

[0009] S2. Calculate the de-icing current based on the initial parameters of the OPGW;

[0010] S3. Real-time wind speed, icing morphology, and route shape are introduced as constraints to correct the de-icing current and obtain the optimal de-icing current;

[0011] S4. Based on the optimal de-icing current, perform dynamic voltage regulation and dynamic adjustment of the de-icing current to complete the line de-icing.

[0012] In step S1, the initial parameters include the current temperature of the OPGW. OPGW permissible temperature Permissible de-icing current range And the initial resistance value R of the conductor.

[0013] Step S1 specifically involves: obtaining the current temperature of the OPGW based on infrared thermometry. Based on the conductor type, obtain the allowable temperature of the OPGW. and the allowable range of de-icing current ;

[0014] Then based on the current temperature of the OPGW Calculate the initial resistance R of the conductor using the following formula: ;in, This is the resistance value of the conductor at 20℃; This represents the temperature coefficient of the conductor.

[0015] In step S2, the de-icing current is calculated based on the initial parameters of the OPGW, expressed by the following formula: ;in, denoted as the de-icing current; a is the rectifier mode selection coefficient; b is the output combination switch selection coefficient. Set the transformer tap for the selected mobile DC de-icing device.

[0016] According to claim 4, the UHV ground wire de-icing control method based on wide-range on-load tap changer is characterized in that the rectifier mode selection coefficient 'a' is determined according to the series and parallel connection of the rectifiers, specifically: when the two bridges of the rectifier are connected in series, the rectifier mode selection coefficient 'a' is 2; when the two bridges of the rectifier are connected in parallel, the rectifier mode selection coefficient 'a' is 1.

[0017] The selection coefficient b of the output combination switch is determined according to the series and parallel connection method of the line to be melted. Specifically, when the line to be melted is two phases in series, the selection coefficient b of the output combination switch is 2; when the line to be melted is two phases in parallel and one in series, the selection coefficient b of the output combination switch is 1.5.

[0018] In step S3, real-time wind speed, icing morphology, and route shape are introduced as constraints to correct the melting current. The following formula is used to constrain the melting current: ; ; ; ; ; ; ;

[0019] Where v is the wind speed parameter, representing the real-time wind speed; h is the icing thickness and the thermal melting coefficient corresponding to the icing type; S is the line structure parameter; and clip is the limiting function, used to ensure that the corrected de-icing current is always within the safe range. The initial melting current is calculated based on the ice thickness and the target melting rate. , , These are the wind speed correction factor, icing correction factor, and line structure correction factor, respectively; v is the real-time wind speed. These are the weighting coefficients; The equivalent thermal fusion coefficient corresponding to the current icing thickness and icing type. For reference, the standard heat transfer coefficient under icing conditions; This is the structural influence coefficient; The line temperature value at the current moment; This represents the control step size; The optimal de-icing current value at any given time; This represents the optimal de-icing current value calculated at the current moment; This represents the convective heat transfer coefficient that varies with the wind speed parameter v. The reference heat transfer coefficient under natural convection conditions; The wind speed heat transfer enhancement coefficient is denoted as T; the ambient temperature is denoted as T. This is the equivalent heat capacity per unit length of the conductor.

[0020] In step S4, the dynamic voltage regulation specifically refers to: based on the optimal de-icing current value obtained in step S3... Select the initial tap position of the transformer and start the wide-range on-load tap changer;

[0021] When the measured current is lower than the optimal de-icing current, the tap changer should be adjusted according to a small-step voltage boosting strategy; the voltage difference at each stage... Express it using the following formula: ;in, This is the output voltage value corresponding to the current tap position; This is the output voltage value corresponding to the next adjacent tap position; This is a single-stage voltage regulation step size.

[0022] The small-step voltage boosting strategy is as follows: when the measured current is lower than the optimal de-icing current, the voltage is adjusted and boosted by one level. After adjustment, the current is waited for to stabilize and then measured again. If the measured current is still lower than the optimal de-icing current, the voltage is adjusted and boosted by one level as described above and measured again after the current stabilizes. This process continues until the measured current reaches and stabilizes at the optimal de-icing current, at which point the voltage boosting is stopped, thus achieving de-icing current control at the start of de-icing.

[0023] The dynamic adjustment of the de-icing current specifically refers to:

[0024] During the de-icing process, the conductor temperature rises over time, leading to increased resistance and a natural decrease in the de-icing current. Furthermore, changes in wind speed and ice thickness also affect the de-icing current. Therefore, to ensure effective de-icing, a proportional adjustment method is used to dynamically maintain the current. When the real-time measured current I meets the requirements... At that time, the transformer is switched to a higher tap; when the real-time measured current I meets the requirements... When the transformer drops one tap, the current tap position is maintained when the real-time measured current I is within ±5% of the optimal de-icing current at the current moment.

[0025] Current detection and current deviation determination are performed at preset cycles, and the transformer tap is dynamically adjusted to achieve current and temperature control during the ice melting process.

[0026] Step S4 also includes: during the de-icing process, monitoring the conductor temperature in real time, and when the temperature reaches... At ℃, to prevent the temperature from exceeding the allowable temperature of the OPGW, the transformer tap position is automatically lowered; in addition, when abnormal line voltage, external short circuit, tripping or other operational risks occur, the de-icing mode is automatically exited, and staff are reminded to confirm to ensure line safety.

[0027] Once all the ice on the line has fallen off and remained stable for a preset time, the ice melting process is stopped. The transformer tap position is then gradually lowered using a step-by-step measurement method, and the entire ice melting process information is recorded for dispatching and archiving.

[0028] The present invention also provides a system for implementing the UHV ground wire de-icing control method based on a wide-range on-load tap-changing transformer, comprising a wide-range on-load tap-changing transformer, a rectifier, a combined disconnect switch, a de-icing line, a data monitoring device, a controller, and a protection and control device;

[0029] The data monitoring device collects data such as ground wire temperature, wind speed, ice thickness and ice type in real time, and uploads the data to the controller;

[0030] The controller calculates the de-icing current according to the received data and the control method described above, and controls the wide-range on-load tap changer to adjust the tap position.

[0031] The wide-range on-load tap-changing transformer controls the current magnitude by adjusting the transformer tap position according to the received controller instructions, thereby controlling the de-icing current;

[0032] The rectifier converts the voltage output from the wide-range on-load tap-changing transformer into DC power, which is then output to the de-icing line via a combination of disconnect switches and protection and control devices to achieve line de-icing.

[0033] The protection and control device monitors the ice melting process. When it detects overcurrent, excessive temperature, sudden wind speed changes, or line abnormalities, the protection and control device automatically reduces the voltage regulation level, limits the ice melting current, or immediately disconnects the ice melting circuit to achieve full-process safety protection.

[0034] This invention discloses an ultra-high voltage (UHV) ground wire de-icing control method and system based on a wide-range on-load tap changer. It applies wide-range on-load tap changer technology to ground wire de-icing scenarios, utilizing an ultra-wide tap changer range of ±40% and a continuously adjustable current capacity of 200A~800A to overcome the technical bottlenecks of traditional de-icing devices, such as the inability to finely adjust the current and the tendency for overshoot or under-icing during the de-icing process. Through continuous voltage-side adjustment, smooth control of the de-icing current is achieved directly, ensuring the de-icing current remains within the optimal range, significantly improving de-icing efficiency and reducing the risk of thermal instability. Simultaneously, this invention employs a "current closed-loop + temperature closed-loop" collaborative control system to correct the deviation between the de-icing current and temperature rise in real time. This allows the system to automatically adjust its output based on changes in line temperature, ice thickness, and wind speed, achieving adaptive de-icing capability that avoids both burning optical fibers and insufficient de-icing. Through dual-loop dynamic correction, de-icing time can be significantly shortened, temperature fluctuations suppressed, and the system's stability and robustness improved under complex conditions such as extreme cold, strong winds, and heavy icing. Compared to traditional experience-based ice melting, this invention transforms ice melting operations from "experience-based decision-making" to "quantitative decision-making + closed-loop control," significantly improving predictability and engineering reliability. Attached Figure Description

[0035] Figure 1 This is a schematic flowchart of the method of the present invention;

[0036] Figure 2 This is a schematic diagram of the system of the present invention. Detailed Implementation

[0037] This invention provides a method for controlling ice melting on ultra-high voltage ground wires based on wide-range on-load tap changers, the flowchart of which is shown below. Figure 1 As shown, it includes the following steps:

[0038] S1. Based on the conductor type and infrared thermometry, obtain and calculate the initial parameters of the OPGW;

[0039] In step S1, the initial parameters include the current temperature of the OPGW. OPGW permissible temperature Permissible de-icing current range And the initial resistance value R of the conductor.

[0040] Step S1 specifically involves: obtaining the current temperature of the OPGW based on infrared thermometry. Based on the conductor type, obtain the allowable temperature of the OPGW. and the allowable range of de-icing current ;

[0041] Then based on the current temperature of the OPGW Calculate the initial resistance R of the conductor using the following formula: ;in, This is the resistance value of the conductor at 20℃; This represents the temperature coefficient of the conductor.

[0042] S2. Calculate the de-icing current based on the initial parameters of the OPGW;

[0043] In step S2, the de-icing current is calculated based on the initial parameters of the OPGW, expressed by the following formula: ;in, denoted as the de-icing current; a is the rectifier mode selection coefficient; b is the output combination switch selection coefficient. Set the transformer tap for the selected mobile DC de-icing device.

[0044] According to claim 4, the UHV ground wire de-icing control method based on wide-range on-load tap changer is characterized in that the rectifier mode selection coefficient 'a' is determined according to the series and parallel connection of the rectifiers, specifically: when the two bridges of the rectifier are connected in series, the rectifier mode selection coefficient 'a' is 2; when the two bridges of the rectifier are connected in parallel, the rectifier mode selection coefficient 'a' is 1.

[0045] The selection coefficient b of the output combination switch is determined according to the series and parallel connection method of the line to be melted. Specifically, when the line to be melted is two phases in series, the selection coefficient b of the output combination switch is 2; when the line to be melted is two phases in parallel and one in series, the selection coefficient b of the output combination switch is 1.5.

[0046] S3. Real-time wind speed, icing morphology, and route shape are introduced as constraints to correct the de-icing current and obtain the optimal de-icing current;

[0047] In step S3, real-time wind speed, icing morphology, and route shape are introduced as constraints to correct the melting current. The following formula is used to constrain the melting current: ; ; ; ; ; ; ;

[0048] Where v is the wind speed parameter, representing the real-time wind speed; h is the icing thickness and the thermal melting coefficient corresponding to the icing type; S is the line structure parameter; and clip is the limiting function, used to ensure that the corrected de-icing current is always within the safe range. The initial melting current is calculated based on the ice thickness and the target melting rate. , , These are the wind speed correction factor, icing correction factor, and line structure correction factor, respectively; v is the real-time wind speed. These are the weighting coefficients; The equivalent thermal fusion coefficient corresponding to the current icing thickness and icing type. For reference, the standard heat transfer coefficient under icing conditions; This is the structural influence coefficient; The line temperature value at the current moment; This represents the control step size; The optimal de-icing current value at any given time; This represents the optimal de-icing current value calculated at the current moment; This represents the convective heat transfer coefficient that varies with the wind speed parameter v. The reference heat transfer coefficient under natural convection conditions; The wind speed heat transfer enhancement coefficient is denoted as T; the ambient temperature is denoted as T. This is the equivalent heat capacity per unit length of the conductor.

[0049] S4. Based on the optimal de-icing current, perform dynamic voltage regulation and dynamic adjustment of the de-icing current to complete the line de-icing.

[0050] In step S4, the dynamic voltage regulation specifically refers to: based on the optimal de-icing current value obtained in step S3... Select the initial tap position of the transformer and start the wide-range on-load tap changer;

[0051] When the measured current is lower than the optimal de-icing current, the tap changer should be adjusted according to a small-step voltage boosting strategy; the voltage difference at each stage... Express it using the following formula: ;in, This is the output voltage value corresponding to the current tap position; This is the output voltage value corresponding to the next adjacent tap position; This is a single-stage voltage regulation step size.

[0052] The small-step voltage boosting strategy is as follows: when the measured current is lower than the optimal de-icing current, the voltage is adjusted and boosted by one level. After adjustment, the current is waited for to stabilize and then measured again. If the measured current is still lower than the optimal de-icing current, the voltage is adjusted and boosted by one level as described above and measured again after the current stabilizes. This process continues until the measured current reaches and stabilizes at the optimal de-icing current, at which point the voltage boosting is stopped, thus achieving de-icing current control at the start of de-icing.

[0053] The dynamic adjustment of the de-icing current specifically refers to:

[0054] During the de-icing process, the conductor temperature rises over time, leading to increased resistance and a natural decrease in the de-icing current. Furthermore, changes in wind speed and ice thickness also affect the de-icing current. Therefore, to ensure effective de-icing, a proportional adjustment method is used to dynamically maintain the current. When the real-time measured current I meets the requirements... At that time, the transformer is switched to a higher tap; when the real-time measured current I meets the requirements... When the transformer drops one tap, the current tap position is maintained when the real-time measured current I is within ±5% of the optimal de-icing current at the current moment.

[0055] Current detection and current deviation determination are performed at preset cycles, and the transformer tap is dynamically adjusted to achieve current and temperature control during the ice melting process.

[0056] Step S4 also includes: during the de-icing process, monitoring the conductor temperature in real time, and when the temperature reaches... At ℃, to prevent the temperature from exceeding the allowable temperature of the OPGW, the transformer tap position is automatically lowered; in addition, when abnormal line voltage, external short circuit, tripping or other operational risks occur, the de-icing mode is automatically exited, and staff are reminded to confirm to ensure line safety.

[0057] Once all the ice on the line has fallen off and remained stable for a preset time, the ice melting process is stopped. The transformer tap position is then gradually lowered using a step-by-step measurement method, and the entire ice melting process information is recorded for dispatching and archiving.

[0058] This invention also provides a system for implementing the UHV ground wire de-icing control method based on a wide-range on-load tap changer, the structural schematic of which is shown below. Figure 2 As shown, it includes a wide-range on-load tap-changing transformer, rectifier, combined disconnect switch, de-icing line, data monitoring device, controller and protection and control device;

[0059] The data monitoring device collects data such as ground wire temperature, wind speed, ice thickness and ice type in real time, and uploads the data to the controller;

[0060] The controller calculates the de-icing current according to the received data and the control method described above, and controls the wide-range on-load tap changer to adjust the tap position.

[0061] The wide-range on-load tap-changing transformer controls the current magnitude by adjusting the transformer tap position according to the received controller instructions, thereby controlling the de-icing current;

[0062] The rectifier converts the voltage output from the wide-range on-load tap-changing transformer into DC power, which is then output to the de-icing line via a combination of disconnect switches and protection and control devices to achieve line de-icing.

[0063] The protection and control device monitors the ice melting process. When it detects overcurrent, excessive temperature, sudden wind speed changes, or line abnormalities, the protection and control device automatically reduces the voltage regulation level, limits the ice melting current, or immediately disconnects the ice melting circuit to achieve full-process safety protection.

Claims

1. A method for controlling ice melting on ultra-high voltage ground wires based on wide-span on-load tap-changing transformers, characterized in that, Includes the following steps: S1. Based on the conductor type and infrared thermometry, obtain and calculate the initial parameters of the OPGW; S2. Calculate the de-icing current based on the initial parameters of the OPGW; S3. Real-time wind speed, icing morphology, and route shape are introduced as constraints to correct the de-icing current and obtain the optimal de-icing current; S4. Based on the optimal de-icing current, perform dynamic voltage regulation and dynamic adjustment of the de-icing current to complete the line de-icing.

2. The method for controlling ice melting of UHV ground wires based on wide-range on-load tap changers according to claim 1, characterized in that, In step S1, the initial parameters include the current temperature of the OPGW. OPGW permissible temperature Permissible de-icing current range And the initial resistance value R of the conductor.

3. The method for controlling ice melting of UHV ground wires based on wide-range on-load tap changers according to claim 1, characterized in that, Step S1 specifically involves: obtaining the current temperature of the OPGW based on infrared thermometry. Based on the conductor type, obtain the allowable temperature of the OPGW. and the allowable range of de-icing current ; Then based on the current temperature of the OPGW Calculate the initial resistance R of the conductor using the following formula: ;in, This is the resistance value of the conductor at 20℃; This represents the temperature coefficient of the conductor.

4. The method for controlling ice melting of UHV ground wires based on wide-range on-load tap changers according to claim 1, characterized in that, In step S2, the de-icing current is calculated based on the initial parameters of the OPGW, expressed by the following formula: ;in, denoted as the de-icing current; a is the rectifier mode selection coefficient; b is the output combination switch selection coefficient. Set the transformer tap for the selected mobile DC de-icing device.

5. The UHV ground wire de-icing control method based on a wide-range on-load tap changer according to claim 4, characterized in that, The rectifier mode selection coefficient 'a' is determined based on the series and parallel connection method of the rectifier. Specifically, when the two bridges of the rectifier are connected in series, the rectifier mode selection coefficient 'a' is 2; when the two bridges of the rectifier are connected in parallel, the rectifier mode selection coefficient 'a' is 1. The selection coefficient b of the output combination switch is determined according to the series and parallel connection method of the line to be melted. Specifically, when the line to be melted is two phases in series, the selection coefficient b of the output combination switch is 2; when the line to be melted is two phases in parallel and one in series, the selection coefficient b of the output combination switch is 1.

5.

6. The method for controlling ice melting of UHV ground wires based on wide-range on-load tap changers according to claim 1, characterized in that, In step S3, real-time wind speed, icing morphology, and route shape are introduced as constraints to correct the melting current. The following formula is used to constrain the melting current: ； ； ； ； ； ； ； Where v is the wind speed parameter, representing the real-time wind speed; h is the icing thickness and the thermal melting coefficient corresponding to the icing type; S is the line structure parameter; and clip is the limiting function, used to ensure that the corrected de-icing current is always within the safe range. The initial melting current is calculated based on the ice thickness and the target melting rate. , , These are the wind speed correction factor, icing correction factor, and line structure correction factor, respectively; v is the real-time wind speed. These are the weighting coefficients; The equivalent thermal fusion coefficient corresponding to the current icing thickness and icing type. For reference, the standard heat transfer coefficient under icing conditions; This is the structural influence coefficient; The line temperature value at the current moment; This represents the control step size; The optimal de-icing current value at any given time; This represents the optimal de-icing current value calculated at the current moment; This represents the convective heat transfer coefficient that varies with the wind speed parameter v. The reference heat transfer coefficient under natural convection conditions; The wind speed heat transfer enhancement coefficient is denoted as T; the ambient temperature is denoted as T. This is the equivalent heat capacity per unit length of the conductor.

7. The method for controlling ice melting of UHV ground wires based on wide-range on-load tap changers according to claim 1, characterized in that, In step S4, the dynamic voltage regulation specifically refers to: based on the optimal de-icing current value obtained in step S3... Select the initial tap position of the transformer and start the wide-range on-load tap changer; When the measured current is lower than the optimal de-icing current, the tap changer should be adjusted according to a small-step voltage boosting strategy; the voltage difference at each stage... Express it using the following formula: ;in, This is the output voltage value corresponding to the current tap position; This is the output voltage value corresponding to the next adjacent tap position; Single-stage voltage regulation step size; The small-step voltage boosting strategy is as follows: when the measured current is lower than the optimal de-icing current, the voltage is adjusted and boosted by one level. After adjustment, the current is waited for to stabilize and then measured again. If the measured current is still lower than the optimal de-icing current, the voltage is adjusted and boosted by one level as described above and measured again after the current stabilizes. This process continues until the measured current reaches and stabilizes at the optimal de-icing current, at which point the voltage boosting is stopped, thus achieving de-icing current control at the start of de-icing.

8. The method for controlling ice melting of UHV ground wires based on wide-range on-load tap changers according to claim 1, characterized in that, The dynamic adjustment of the de-icing current specifically refers to: During the de-icing process, the temperature of the conductor increases over time, leading to an increase in resistance. As a result, the de-icing current will naturally decrease. In addition, changes in wind speed and ice thickness will also affect the de-icing current. Therefore, to ensure the ice-melting effect, a proportional adjustment method is used to dynamically maintain the current. When the real-time measured current I meets the requirements... At that time, the transformer is switched to a higher tap; when the real-time measured current I meets the requirements... When the transformer drops one tap, the current tap position is maintained when the real-time measured current I is within ±5% of the optimal de-icing current at the current moment. Current detection and current deviation determination are performed at preset cycles, and the transformer tap is dynamically adjusted to achieve current and temperature control during the ice melting process.

9. The method for controlling ice melting of UHV ground wires based on wide-range on-load tap changers according to claim 1, characterized in that, Step S4 also includes: during the de-icing process, monitoring the conductor temperature in real time, and when the temperature reaches... At ℃, to prevent the temperature from exceeding the allowable temperature of OPGW, the transformer tap position is automatically lowered; in addition, when abnormal line voltage, external short circuit, tripping or other operational risks occur, the de-icing mode is automatically exited, and staff are reminded to confirm to ensure line safety. Once all the ice on the line has fallen off and remained stable for a preset time, the ice melting process is stopped. The transformer tap position is then gradually lowered using a step-by-step measurement method, and the entire ice melting process information is recorded for dispatching and archiving.

10. A system for implementing the UHV ground wire de-icing control method based on a wide-range on-load tap changer as described in any one of claims 1 to 9, characterized in that, This includes wide-range on-load tap-changing transformers, rectifiers, combined disconnectors, de-icing lines, data monitoring devices, controllers, and protection and control devices. The data monitoring device collects data on ground wire temperature, wind speed, ice thickness, and ice type in real time, and uploads the data to the controller. The controller calculates the de-icing current according to the received data and the control method described above, and controls the wide-range on-load tap changer to adjust the tap position. The wide-range on-load tap-changing transformer controls the current magnitude by adjusting the transformer tap position according to the received controller instructions, thereby controlling the de-icing current; The rectifier converts the voltage output from the wide-range on-load tap-changing transformer into DC power, which is then output to the de-icing line via a combination of disconnect switches and protection and control devices to achieve line de-icing. The protection and control device monitors the ice melting process. When it detects excessive current, excessive temperature, sudden wind speed change, or abnormal line conditions, the protection and control device automatically reduces the voltage regulation level, limits the ice melting current, or immediately disconnects the ice melting circuit to achieve full-process safety protection.

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