Uninterrupted ground wire ice melting device and method for extra-high voltage alternating current lead

Abstract

The invention provides an uninterrupted ground wire ice melting device and method for an extra-high voltage alternating-current wire, and relates to the technical field of line ice melting, and the ice melting device comprises a rectifier, an ice melting cable, a tower, a ground wire coupled with the tower, and a ground wire transient voltage suppression device. The ice-melting cable is electrically connected with the output end of the rectifier and the first end of the ground wire, and the second end of the ground wire is short-circuited and grounded; the ground wire transient voltage suppression device and the ice-melting cable are connected in parallel and grounded, and the two ends of the ice-melting cable are electrically connected with the ground wire transient voltage suppression device separately. According to the ice melting device provided by the invention, the ground wire transient voltage suppression device is additionally arranged, so that the transient induced voltage of the ground wire is suppressed in a certain range when faults such as insulator flashover and wire grounding short circuit occur in the extra-high voltage alternating current transmission line, and the problem that the ground wire is damaged when the extra-high voltage alternating current wire is subjected to ice melting without power failure is solved. Therefore, safe and stable operation of the ice melting device can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of line deicing, and in particular to a device and method for deicing a ground wire of an ultra-high voltage alternating current conductor without power outage. Background Art

[0002] For UHV AC transmission lines, the ground wire is usually located above the transmission line, with a large transmission span and no current. Compared with the transmission line conductor, the ground wire is more prone to ice disasters in winter, and is prone to power outages such as line breakage and tower damage, which poses a great threat to the safety of UHV transmission lines connecting large energy bases. In terms of ice melting, the ground wire is different from the conductor, which can be directly applied with DC current to melt the ice. Since the ground wire is directly connected to the tower, DC current cannot be directly applied to melt the ice.

[0003] In order to facilitate the de-icing of the ground wire, in the prior art, the ground wire is generally insulated and transformed, and the end of the ground wire is short-circuited and connected in series to a DC de-icing circuit, and the de-icing device provides a DC current to heat and de-icer. However, when the ground wire is de-iced, if the UHV transmission line is not stopped, there will be a very high steady-state induced voltage on the UHV transmission line that is not stopped. The excessively high steady-state induced voltage will exceed the safe voltage range of the de-icing device, causing the de-icing device to be locked or damaged, reducing the safety of de-icing and causing huge economic losses. In addition, when an insulator flashover or a conductor grounding short circuit occurs in the UHV AC transmission line, a high-amplitude transient induced overvoltage will be generated on the ground wire, endangering the de-icing equipment and personal safety.

[0004] Therefore, how to improve the above problems has become one of the technical issues that need to be solved urgently at this stage. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a device and method for melting ice on the ground wire of an ultra-high voltage AC conductor without power outage, so as to achieve ice melting on the ground wire of the ultra-high voltage AC conductor without power outage and improve the safety of the ice melting device.

[0006] In a first aspect, the present disclosure provides a non-stop ground wire ice melting device for an ultra-high voltage AC conductor, comprising a rectifier, an ice melting cable, a pole tower, a ground wire coupled to the pole tower, and a ground wire transient voltage suppression device;

[0007] The first end of the ice-melting cable is electrically connected to the output end of the rectifier through an ice-melting knife switch, the second end of the ice-melting cable is electrically connected to the first end of the ground wire through the knife switch under the tower, and the second end of the ground wire is short-circuited to ground;

[0008] The ground transient voltage suppression device is connected to the ground in parallel with the ice-melting cable, and both ends of the ice-melting cable are electrically connected to the ground transient voltage suppression device separately;

[0009] The rectifier is used to provide output current for the ice melting device;

[0010] The ice-melting cable is used to transmit ice-melting current;

[0011] The ground line transient voltage suppression device is used to suppress the transient voltage of the ground line.

[0012] Optionally, where:

[0013] An insulator is provided between the ground wire and the pole tower, and the insulator is connected in parallel with a lightning protection gap.

[0014] Optionally, where:

[0015] The insulator is one of a composite insulator, a glass insulator and a ceramic insulator.

[0016] Optionally, where:

[0017] The number of the pole towers is greater than or equal to 3, and the ground wire is transposed at least once between the pole towers.

[0018] Optionally, where:

[0019] The ground transient voltage suppression device includes two branches, the first of which includes a nonlinear resistor, a first end of which is electrically connected to the ice-melting cable, and a second end is grounded; the second is a discharge gap, which is connected in parallel with the nonlinear resistor.

[0020] Optionally, where:

[0021] A power resistor is also included, and the power resistor is coupled between the positive electrode and the negative electrode of the output end of the rectifier.

[0022] Optionally, where:

[0023] The ice-melting knife gates include a first ice-melting knife gate and a second ice-melting knife gate, and the knife gates under the tower include a first knife gate under the tower and a second knife gate under the tower;

[0024] The positive electrode of the output end of the rectifier is electrically connected to the ice-melting cable through a first ice-melting knife switch, and the negative electrode of the output end of the rectifier is electrically connected to the ice-melting cable through a second ice-melting knife switch;

[0025] The ground wire is electrically connected to the ice-melting cable corresponding to the positive pole of the output end of the rectifier through the first under-tower knife switch, and is electrically connected to the ice-melting cable corresponding to the negative pole of the output end of the rectifier through the second under-tower knife switch.

[0026] Optionally, where:

[0027] The first end of the ice-melting cable comprises an induced voltage detection point, and the induced voltage detection point is used to detect the induced voltage of the ground wire when the ground wire is connected to the ice-melting device.

[0028] In a second aspect, the present disclosure further provides a method for melting ice on a ground wire of an ultra-high voltage AC conductor without power outages, wherein the device for melting ice on a ground wire of an ultra-high voltage AC conductor without power outages comprises a pole tower, a ground wire coupled to the pole tower, a ground wire transient voltage suppression device, an ice melting cable, and a rectifier;

[0029] The first end of the ice-melting cable is electrically connected to the output end of the rectifier through an ice-melting knife switch, the second end of the ice-melting cable is electrically connected to the first end of the ground wire through the knife switch under the tower, and the second end of the ground wire is short-circuited to ground;

[0030] The ground transient voltage suppression device is connected to the ground in parallel with the ice-melting cable, and both ends of the ice-melting cable are electrically connected to the ground transient voltage suppression device separately;

[0031] The ice melting method comprises:

[0032] Closing the knife switch under the tower to electrically connect the ground wire with the ice-melting cable;

[0033] Detecting at the first end of the ice-melting cable whether the induced voltage of the ground line meets the safety voltage range of the ice-melting device; when the induced voltage of the ground line meets the safety voltage range of the ice-melting device, closing the ice-melting knife switch;

[0034] The rectifier is operated to adjust the output current of the rectifier to provide ice-melting current for the ice-melting device.

[0035] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0036] The present invention provides a non-stop ground wire ice melting device and method for ultra-high voltage AC conductors, wherein the ice melting device comprises a rectifier, an ice melting cable, a pole tower, a ground wire coupled to the pole tower, and a ground wire transient voltage suppression device; the first end of the ice melting cable is electrically connected to the output end of the rectifier through an ice melting knife switch, the second end of the ice melting cable is electrically connected to the first end of the ground wire through a knife switch under the tower, and the second end of the ground wire is short-circuited to the ground; the ground wire transient voltage suppression device is connected to the ground in parallel with the ice melting cable, and the two ends of the ice melting cable are electrically connected to the ground wire transient voltage suppression device separately; the rectifier is used to provide output current for the ice melting device; the ice melting cable is used to transmit ice melting current; and the ground wire transient voltage suppression device is used to suppress the transient voltage of the ground wire. The ice melting device provided by the present invention suppresses the transient induced voltage of the ground wire within a certain range when faults such as insulator flashover and conductor grounding short circuit occur in the ultra-high voltage AC transmission line by adding a ground wire transient voltage suppression device. This is beneficial to solving the problem of excessively high ground wire induced voltage of the ultra-high voltage AC transmission line when the ground wire of the ultra-high voltage AC conductor is ice-melted without power outage, thereby ensuring the safe and stable operation of the ice melting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0039] Figure 1 The figure shows a schematic diagram of a non-stop ground wire ice melting device for ultra-high voltage AC conductors provided by an embodiment of the present disclosure;

[0040] Figure 2 Shown is a schematic diagram of a ground line transient voltage suppression device provided by an embodiment of the present disclosure;

[0041] Figure 3 Shown is a comparative schematic diagram of the steady-state induced voltage of the ground wire provided by the embodiment of the present disclosure;

[0042] Figure 4 Shown is a comparative schematic diagram of the transient induced voltage of the ground wire provided by the embodiment of the present disclosure;

[0043] Figure 5 The figure is a schematic flow chart of a method for melting ice on a ground wire of an ultra-high voltage AC conductor without power outage provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0044] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0045] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0046] Figure 1 FIG. 1 is a schematic diagram of an uninterrupted ground wire ice melting device for an ultra-high voltage AC conductor provided by an embodiment of the present disclosure. Figure 1 The present disclosure provides a ground wire de-icing device 100 for ultra-high voltage AC conductors without power outages, comprising a rectifier 10, an de-icing cable 20, a pole tower 30, a ground wire 00 coupled to the pole tower 30, and a ground wire transient voltage suppression device 40.

[0047] The first end of the ice-melting cable 20 is electrically connected to the output end of the rectifier 10 through the ice-melting knife switch 12, the second end of the ice-melting cable 20 is electrically connected to the first end of the ground wire 00 through the under-tower knife switch 23, and the second end of the ground wire 00 is short-circuited to ground; the ground wire transient voltage suppression device 40 is connected to the ground in parallel with the ice-melting cable 20, and the two ends of the ice-melting cable 20 are electrically connected to the ground wire transient voltage suppression device 40 respectively.

[0048] The rectifier 10 is used to provide output current for the ice-melting device 100 ; the ice-melting cable 20 is used to transmit the ice-melting current; and the ground wire transient voltage suppression device 40 is used to suppress the transient voltage of the ground wire 00 .

[0049] It should be noted that UHV refers to AC transmission voltage levels above 1000 kV and DC transmission voltage levels of ±800 kV and above. UHV transmission can achieve optimal allocation of energy resources between different regions. For example, on a global scale, the distribution of energy resources is often uneven. For example, energy is concentrated in certain specific areas, while areas with high electricity demand may lack these energy resources. UHV transmission can transmit electricity from energy-rich areas to energy-poor but high-demand areas, promoting coordinated regional economic development. Therefore, it is very important and one of the technical problems to be solved urgently to achieve ground wire ice melting without power outage for UHV AC conductors.

[0050] It should also be noted that the principle of line ice melting is to make the conductor generate a large amount of Joule heat, thereby melting the ice covering the line.

[0051] The present disclosure provides a ground wire deicing device 100 for non-stop power supply of ultra-high voltage AC conductors, comprising a rectifier 10, an deicing cable 20, a pole tower 30, a ground wire 00 coupled to the pole tower 30, and a ground wire transient voltage suppression device 40. The ground wire 00 coupled to the pole tower 30 is a line that needs to be deiced in the present disclosure, the ground wire 00 is coupled to the pole tower 30, the first end of the ground wire 00 is electrically connected to the deicing cable 20 through the under-tower knife switch 23, and the second end is short-circuited to the ground, and the deicing cable 20 is used to transmit deicing current, so that the ground wire 00 generates a large amount of Joule heat, thereby melting the ice on the line.

[0052] The first end of the ice-melting cable 20 is coupled to the rectifier 10, and the second end is coupled to the ground wire 00. Specifically, the first end of the ice-melting cable 20 is electrically connected to the output end of the rectifier 10 through the ice-melting knife switch 12, and the second end is electrically connected to the first end of the ground wire 00 through the under-tower knife switch 23. The rectifier 10 is used to provide output current for the ice-melting device 100. The output end of the rectifier 10 includes a positive output end and a negative output end. The positive output end is connected to the corresponding ice-melting cable 20, and the negative output end is connected to the corresponding ice-melting cable 20. The ice-melting cable 20 is then connected to the first end of the ground wire 00, and the second end of the ground wire 00 is short-circuited to the ground to form an ice-melting loop.

[0053] At the first end and the second end of the ice-melting cable 20, a ground wire transient voltage suppression device 40 is provided. The ground wire transient voltage suppression device 40 is connected to the ground in parallel with the ice-melting cable 20. The ground wire transient voltage suppression device 40 is used to suppress the transient voltage of the ground wire 00. When the ground wire 00 of the ultra-high voltage AC conductor is de-iced without power outage, the ground wire transient voltage suppression device 40 is helpful to suppress the transient induced voltage of the ground wire 00 within a certain range when the ultra-high voltage AC conductor has an insulator flashover, a conductor grounding short circuit, and other faults, thereby improving the safety of the ice-melting device 100.

[0054] Figure 2 FIG. 1 is a schematic diagram of a ground transient voltage suppression device provided by an embodiment of the present disclosure. Please refer to FIG. Figure 1 and Figure 2 The present disclosure provides an optional implementation manner in which the ground transient voltage suppression device 40 includes two branches, the first branch includes a nonlinear resistor 41, a first end of the nonlinear resistor 41 is electrically connected to the ice-melting cable 20, and a second end is grounded; the second branch is a discharge gap 42, and the discharge gap 42 is connected in parallel with the nonlinear resistor 41.

[0055] Specifically, the present embodiment provides a setting method of a ground transient voltage suppression device 40, wherein the ground transient voltage suppression device 40 includes two branches, the two branches are connected in parallel, wherein the first branch includes a nonlinear resistor 41, when a transient overvoltage is caused by lightning strike or other reasons, the nonlinear resistor 41 is turned on, which is helpful to prevent the overvoltage from damaging the ice melting device 100. Optionally, the nonlinear resistor 41 is a zinc oxide nonlinear resistor, and it should be noted that the present disclosure is only described by this example and is not limited to this. The second branch is a discharge gap 42, when a fault such as an insulator flashover or a conductor grounding short circuit occurs in the transmission line, the discharge gap 42 discharges the charge to suppress the transient overvoltage within a certain range.

[0056] It should be noted that insulator flashover refers to the phenomenon that the gas (usually air) on the surface of the insulator breaks down and discharges, causing the insulation performance of the insulator to be temporarily or permanently lost. Under normal circumstances, insulators can withstand a certain voltage and maintain an insulating state, but when the electric field strength on the surface of the insulator exceeds the breakdown electric field strength of the air, or a conductive channel is formed on the surface of the insulator, flashover will occur. The flashover process is usually accompanied by the generation of an arc, which will form a conductive path along the surface of the insulator or in the gap of the insulator.

[0057] The UHV AC conductor non-stop ground wire ice-melting device 100 provided by the present invention suppresses the transient induced voltage of the ground wire 00 within a certain range when the UHV AC transmission line has faults such as insulator flashover and conductor grounding short circuit, by adding a ground wire transient voltage suppression device 40. This is helpful to solve the problem of excessively high induced voltage of the ground wire 00 of the UHV AC transmission line when the ground wire 00 of the UHV AC conductor is melted without power outage, thereby ensuring the safe and stable operation of the ice-melting device 100.

[0058] It should be noted that the ground wire 00 in the non-stop ground wire ice melting device 100 provided by the present disclosure is coupled with the pole tower 30, and coupling means that the ground wire 00 is not directly electrically connected with the pole tower 30. The present disclosure provides an optional implementation in which an insulator is included between the ground wire 00 and the pole tower 30, and the insulator is connected in parallel with the lightning protection gap.

[0059] Specifically, insulators are a special type of insulating control used to support and fix the conductors in overhead transmission lines and to maintain a sufficient insulation distance between the conductors and the towers or the ground, thereby preventing current from leaking from the conductors to the towers or the ground, and ensuring the normal operation of the transmission lines. At the same time, the insulator is connected in parallel with the lightning protection gap, which is mainly composed of two electrodes with a certain gap distance between the electrodes. Based on the insulation breakdown characteristics of the air gap, under normal circumstances, the gap remains insulated, allowing the line to operate normally. When a lightning overvoltage strikes, the electric field strength between the gaps exceeds the insulation strength of the air, the air is broken down and ionized, forming a conductive channel that introduces lightning current into the ground, thereby protecting the lines and electrical equipment from damage caused by lightning strikes.

[0060] Furthermore, the present disclosure provides an optional implementation manner in which the insulator is one of a composite insulator, a glass insulator and a ceramic insulator.

[0061] It should be noted that composite insulators are composed of organic polymer materials and core rods. The core rods are usually made of glass fiber reinforced resin materials, which have high mechanical strength and can withstand large tensile forces. The outer shed is generally made of silicone rubber and other materials. This material has good hydrophobicity and can effectively prevent rainwater from forming a continuous conductive channel on the surface of the insulator. Composite insulators are light in weight, easy to install, and have good pollution resistance. They can better play an insulating role in a more polluted environment. For example, in industrial pollution areas or coastal salt spray environments, composite insulators can reduce the occurrence of pollution flashover accidents.

[0062] Glass insulators are made of glass as the main material. They have excellent electrical insulation properties, and their internal structure is uniform and has few impurities, so they can better maintain insulation under the action of the electric field. Glass insulators have high transparency, which makes it easy to inspect defects inside them. Once cracks and other problems occur, they can be easily discovered. For example, during daily inspections, staff can observe whether there are cracks inside the glass insulator with the naked eye and discover potential safety hazards in a timely manner.

[0063] Ceramic insulators are traditional insulator materials. Made of raw materials such as porcelain clay, they have good insulation properties, mechanical strength and chemical stability. Ceramic insulators have a high surface hardness and can withstand a certain degree of wear and external impact. For example, in some areas with harsh environmental conditions, such as places with strong winds and sand, the high hardness of ceramic insulators can effectively resist the erosion of sand particles on their surfaces.

[0064] Please continue to refer to Figure 1 The present disclosure provides an optional implementation mode in which the number of pole towers 30 is greater than or equal to 3, and the ground wire 00 is transposed at least once between the pole towers 30.

[0065] Specifically, the ground wire 00 is coupled to the pole tower 30. When the number of pole towers 30 is greater than or equal to 3 in this embodiment, the ground wire 00 is transposed at least once between the pole towers 30. Such a configuration is conducive to reducing the steady-state induced voltage of the ground wire 00. It should be noted that transposition refers to swapping the ground wire corresponding to the positive side with the ground wire corresponding to the negative side. The present disclosure adopts a method of rearranging the position of the ground wire 00 to suppress the steady-state induced overvoltage existing in the ground wire 00, and solves the problem that the amplitude of the induced voltage of the ground wire 00 increases when the ice melting distance increases, resulting in the inability to safely connect the ice melting device 100, thereby facilitating increasing the single ice melting distance of the ice melting device 100.

[0066] The embodiment of the present disclosure adopts the method of ground line spacing transposition to suppress the steady-state induced voltage and transient induced voltage of the ground line after insulation transformation. Figure 3 FIG. 1 is a comparative schematic diagram of the steady-state induced voltage of the ground wire provided in the embodiment of the present disclosure. Figure 4 FIG. 1 is a schematic diagram showing a comparison of transient induced voltage of a ground line provided by an embodiment of the present disclosure. Please refer to FIG. Figure 3 and Figure 4 , Figure 3 (a) is a schematic diagram of the steady-state induced voltage of the ground line in the embodiment of the present disclosure, Figure 3 (b) is a schematic diagram of the steady-state induced voltage of the ground wire in the prior art. Figure 4 (a) is a schematic diagram of the transient induced voltage of the ground line in the embodiment of the present disclosure, Figure 3 (b) is a schematic diagram of the transient induced voltage of the ground line in the prior art. In the figure, the horizontal axis represents time and the vertical axis represents voltage amplitude. It can be seen from the figure that the steady-state induced voltage and the transient induced voltage of the ice melting device provided by the embodiment of the present disclosure are significantly reduced.

[0067] Please continue to refer to Figure 1 The present disclosure provides an optional implementation manner, which further includes a power resistor 50 , and the power resistor 50 is coupled between the positive electrode and the negative electrode of the output end of the rectifier 10 .

[0068] Specifically, in this embodiment, the UHV AC conductor non-stop ground wire de-icing device 100 further includes a power resistor 50, which is a resistor that can withstand a relatively large power in a circuit. In this embodiment, the power resistor 50 is arranged between the positive and negative electrodes of the output end of the rectifier 10, which plays a certain voltage dividing role, reduces the current flowing through the de-icing cable 20, and is conducive to preventing the current flowing through the ground wire 00 from being too large, thereby facilitating the safety of the de-icing device 100.

[0069] It should be noted that the drawings in the present disclosure are for illustration only and do not represent the actual structure of the non-stop ground wire ice melting device 100 for ultra-high voltage AC conductors, nor are they limited thereto. For example, please refer to Figure 1 , Figure 1A filter capacitor 60 is also provided at the first end of the ground line, and the filter capacitor 60 filters out the frequency components that are not needed by the circuit, which is more conducive to ice melting of the line.

[0070] Please continue to refer to Figure 1 The present disclosure provides an optional implementation mode in which the ice-melting knife gate 12 includes a first ice-melting knife gate 121 and a second ice-melting knife gate 122, and the lower tower knife gate 23 includes a first lower tower knife gate 231 and a second lower tower knife gate 232;

[0071] The positive electrode of the output end of the rectifier 10 is electrically connected to the ice-melting cable 20 through the first ice-melting knife switch 121, and the negative electrode of the output end of the rectifier 10 is electrically connected to the ice-melting cable 20 through the second ice-melting knife switch 122;

[0072] The ground wire 00 is electrically connected to the ice-melting cable 20 corresponding to the positive pole of the output end of the rectifier 10 through the first under-tower switch 231 , and is electrically connected to the ice-melting cable 20 corresponding to the negative pole of the output end of the rectifier 10 through the second under-tower switch 232 .

[0073] Specifically, in the non-stop ground wire ice melting device 100 for ultra-high voltage AC conductors provided by the present disclosure, the ice melting cable 20 is electrically connected to the output end of the rectifier 10 through the ice melting knife switch 12, and is electrically connected to the ground wire 00 through the under-tower knife switch 23. When ice melting is performed, the under-tower knife switch 23 is closed to electrically connect the ground wire 00 to the ice melting cable 20; at the first end of the ice melting cable 20, it is detected whether the induced voltage of the ground wire 00 meets the safety voltage range of the ice melting device 100. If it meets, the ice melting knife switch 12 is closed to connect the ice melting cable 20 and the output end of the rectifier 10. The present disclosure controls whether the ice melting line is connected by setting the ice melting knife switch 12 and the under-tower knife switch 23.

[0074] Please continue to refer to Figure 1 In order to further improve the safety of the ice melting device 100, the UHV AC conductor non-stop ground wire ice melting device 100 provided by the present disclosure detects whether the induced voltage of the ground wire 00 meets the safe voltage range of the ice melting device 100 before starting to melt ice. The present disclosure provides an optional implementation method in which the first end of the ice melting cable 20 includes an induced voltage detection point 2, and the induced voltage detection point 2 includes a positive induced voltage detection point 2p and a negative induced voltage detection point 2n. The induced voltage detection point 2 is used to detect the induced voltage of the ground wire 00 when the ground wire 00 is connected to the ice melting device 100. In this way, it is beneficial to control the ground wire induced voltage within a safe range before detection, which is further beneficial to improve the safety of the ice melting system 100.

[0075] Based on the same inventive concept, the present disclosure also provides a method for melting ice on a ground wire of an ultra-high voltage AC conductor without power outage. Figure 5The figure is a flow chart of a method for melting ice on a ground wire of a UHV AC conductor without power outage provided by the embodiment of the present disclosure. Figure 1 and Figure 5 The ice melting method adopts a non-stop ground wire ice melting device 100 for ultra-high voltage AC conductor to melt ice. The ice melting device 100 includes a pole tower 30, a ground wire 00 coupled to the pole tower 30, a ground wire transient voltage suppression device 40, an ice melting cable 20 and a rectifier 10; the first end of the ice melting cable 20 is electrically connected to the output end of the rectifier 10 through an ice melting knife switch 12, the second end of the ice melting cable 20 is electrically connected to the first end of the ground wire 00 through a knife switch 23 under the tower, and the second end of the ground wire 00 is short-circuited to ground; the ground wire transient voltage suppression device 40 is connected to the ground in parallel with the ice melting cable 20, and the two ends of the ice melting cable 20 are electrically connected to the ground wire transient voltage suppression device 40 respectively;

[0076] Ice melting methods include:

[0077] S01, close the knife switch 23 under the tower to electrically connect the ground wire 00 with the ice-melting cable 20;

[0078] S02, detecting at the first end of the ice-melting cable 20 whether the induced voltage of the ground wire 00 meets the safety voltage range of the ice-melting device 100; when the induced voltage of the ground wire 00 meets the safety voltage range of the ice-melting device 100, closing the ice-melting knife switch 12;

[0079] S03 , operating the rectifier 10 , adjusting the output current of the rectifier 10 , and providing ice-melting current for the ice-melting device 100 .

[0080] It should be noted that the method for melting ice on the ground wire of the UHV AC conductor without power outage provided by the present disclosure includes but is not limited to steps S01 to S03. The ice melting method uses the device 100 for melting ice on the ground wire of the UHV AC conductor without power outage to melt ice on the ground wire 00. The present disclosure detects the induced voltage of the ground wire 00 before melting ice. When the induced voltage of the ground wire 00 meets the safe voltage range of the ice melting device 100, ice melting is performed, which is conducive to improving the safety of ice melting. In the ice melting system 100 used in the ice melting method provided by the present disclosure, a ground wire transient voltage suppression device 40 is added to suppress the transient induced voltage of the ground wire 00 within a certain range when the UHV AC transmission line has an insulator flashover, a conductor grounding short circuit or other faults, which is conducive to solving the problem of too high induced voltage of the ground wire 00 of the UHV AC transmission line when the ground wire 00 of the UHV AC conductor is melted without power outage, thereby ensuring the safe and stable operation of the ice melting device 100.

[0081] It can be seen from the above embodiments that the device and method for melting ice on the ground wire of an ultra-high voltage AC conductor without power outages provided by the present disclosure at least achieve the following beneficial effects:

[0082] The present invention provides a non-stop ground wire ice melting device and method for ultra-high voltage AC conductors, wherein the ice melting device comprises a rectifier, an ice melting cable, a pole tower, a ground wire coupled to the pole tower, and a ground wire transient voltage suppression device; the first end of the ice melting cable is electrically connected to the output end of the rectifier through an ice melting knife switch, the second end of the ice melting cable is electrically connected to the first end of the ground wire through a knife switch under the tower, and the second end of the ground wire is short-circuited to the ground; the ground wire transient voltage suppression device is connected to the ground in parallel with the ice melting cable, and the two ends of the ice melting cable are electrically connected to the ground wire transient voltage suppression device separately; the rectifier is used to provide output current for the ice melting device; the ice melting cable is used to transmit ice melting current; and the ground wire transient voltage suppression device is used to suppress the transient voltage of the ground wire. The ice melting device provided by the present invention suppresses the transient induced voltage of the ground wire within a certain range when faults such as insulator flashover and conductor grounding short circuit occur in the ultra-high voltage AC transmission line by adding a ground wire transient voltage suppression device. This is beneficial to solving the problem of excessively high ground wire induced voltage of the ultra-high voltage AC transmission line when the ground wire of the ultra-high voltage AC conductor is ice-melted without power outage, thereby ensuring the safe and stable operation of the ice melting device.

[0083] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0084] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A non-stop ground wire ice melting device for ultra-high voltage AC conductors, characterized in that: It includes a rectifier, an ice-melting cable, a pole tower, a ground wire coupled to the pole tower, and a ground wire transient voltage suppression device; The first end of the ice-melting cable is electrically connected to the output end of the rectifier through an ice-melting knife switch, the second end of the ice-melting cable is electrically connected to the first end of the ground wire through the knife switch under the tower, and the second end of the ground wire is short-circuited to ground; The ground transient voltage suppression device is connected to the ground in parallel with the ice-melting cable, and both ends of the ice-melting cable are electrically connected to the ground transient voltage suppression device separately; The rectifier is used to provide output current for the ice melting device; The ice-melting cable is used to transmit ice-melting current; The ground line transient voltage suppression device is used to suppress the transient voltage of the ground line.

2. The non-stop ground wire ice melting device for UHV AC conductors according to claim 1, characterized in that: An insulator is provided between the ground wire and the pole tower, and the insulator is connected in parallel with a lightning protection gap.

3. The non-stop ground wire ice melting device for UHV AC conductor according to claim 2, characterized in that: The insulator is one of a composite insulator, a glass insulator and a ceramic insulator.

4. The non-stop ground wire ice melting device for UHV AC conductor according to claim 1, characterized in that: The number of the pole towers is greater than or equal to 3, and the ground wire is transposed at least once between the pole towers.

5. The non-stop ground wire ice melting device for UHV AC conductor according to claim 1, characterized in that: The ground transient voltage suppression device includes two branches, the first of which includes a nonlinear resistor, a first end of which is electrically connected to the ice-melting cable, and a second end is grounded; the second is a discharge gap, which is connected in parallel with the nonlinear resistor.

6. The non-stop ground wire ice melting device for UHV AC conductor according to claim 1, characterized in that: A power resistor is also included, and the power resistor is coupled between the positive electrode and the negative electrode of the output end of the rectifier.

7. The non-stop ground wire ice melting device for UHV AC conductors according to claim 1, characterized in that: The ice-melting knife gates include a first ice-melting knife gate and a second ice-melting knife gate, and the knife gates under the tower include a first knife gate under the tower and a second knife gate under the tower; The positive electrode of the output end of the rectifier is electrically connected to the ice-melting cable through a first ice-melting knife switch, and the negative electrode of the output end of the rectifier is electrically connected to the ice-melting cable through a second ice-melting knife switch; The ground wire is electrically connected to the ice-melting cable corresponding to the positive pole of the output end of the rectifier through the first under-tower knife switch, and is electrically connected to the ice-melting cable corresponding to the negative pole of the output end of the rectifier through the second under-tower knife switch.

8. The non-stop ground wire ice melting device for UHV AC conductors according to claim 1, characterized in that: The first end of the ice-melting cable comprises an induced voltage detection point, and the induced voltage detection point is used to detect the induced voltage of the ground wire when the ground wire is connected to the ice-melting device.

9. A method for melting ice on ground wires of ultra-high voltage AC conductors without power outage, characterized in that: The non-stop ground wire ice melting device for ultra-high voltage AC conductors comprises a pole tower, a ground wire coupled to the pole tower, a ground wire transient voltage suppression device, an ice melting cable and a rectifier; The first end of the ice-melting cable is electrically connected to the output end of the rectifier through an ice-melting knife switch, the second end of the ice-melting cable is electrically connected to the first end of the ground wire through the knife switch under the tower, and the second end of the ground wire is short-circuited to ground; The ground transient voltage suppression device is connected to the ground in parallel with the ice-melting cable, and both ends of the ice-melting cable are electrically connected to the ground transient voltage suppression device separately; The ice melting method comprises: Closing the knife switch under the tower to electrically connect the ground wire with the ice-melting cable; Detecting at the first end of the ice-melting cable whether the induced voltage of the ground line meets the safety voltage range of the ice-melting device; when the induced voltage of the ground line meets the safety voltage range of the ice-melting device, closing the ice-melting knife switch; The rectifier is operated to adjust the output current of the rectifier to provide ice-melting current for the ice-melting device.

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