Induced voltage suppression system and method

Abstract

The invention relates to an induced voltage suppression system and method. The induced voltage suppression system comprises an ice melting device, a ground wire, a three-phase transmission conductor, a voltage measuring device and a conductor transposition module, the ground wire and the voltage measuring device are connected with the ice melting device; the three-phase transmission conductor is connected with the conductor transposition module; the wire transposition module is used for changing the arrangement sequence of each phase of power transmission wire in the three phases of power transmission wires along the reference direction so as to restrain the steady-state induction overvoltage of the ground wire within the safety range of the ice melting device; the voltage measuring device is used for measuring the induced voltage of the ground wire, and when the induced voltage of the ground wire is within the safety voltage range of the ice melting device, the ice melting device outputs direct-current voltage to melt ice on the ground wire. Therefore, by changing the arrangement sequence of the three-phase transmission conductors along the reference direction, the steady-state induction overvoltage is suppressed, so that the ice melting device can normally work in a safe voltage range, and long-distance and high-efficiency single-time ground wire ice melting can be further realized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of ultra-high voltage alternating current power transmission, and in particular to an induced voltage suppression system and method. Background Art

[0002] The AC ultra-high / ultra-high voltage transmission line has a transmission capacity of nearly 10 million kilowatts. It is the main artery of my country's energy transportation of "sending electricity from west to east and north to south", and is an important carrier for optimizing energy resource allocation and achieving dual carbon goals. The ground wire of the ultra-high voltage line is higher than the conductor, and the wind speed is greater at the location. In addition, the diameter of the ground wire is thinner, and there is no current on the ground wire, which makes it more prone to line shutdown accidents caused by severe icing. After the ground wire is severely iced, the risk of wire clamp damage, ground wire slippage, and increased sag increases sharply, which can easily cause the conductor to discharge from the ground wire, the ground wire to break, and cause line tripping, power outages and other faults. Because the thickness of ice on the ground wire can be as high as 50mm or more, the anti-ice transformation method of strengthening the mechanical strength of the ground wire and the bracket is limited to improve the anti-ice ability of the ground wire, and the cost is as high as millions of yuan per kilometer.

[0003] Electrically heating and melting ice on the ground wire after insulation modification is one of the effective measures to solve the problem of ground wire icing. However, when using the existing ice-melting device to apply voltage to the ground wire to melt the ice, due to the live operation of the transmission line conductor, a relatively high-amplitude steady-state induced overvoltage will be generated in the ground wire, affecting the normal access of the ice-melting device. For example, the ice-melting device is prone to damage after access, making it difficult to achieve long-distance, high-efficiency single-time ground wire melting. Summary of the invention

[0004] In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides an induced voltage suppression system and method.

[0005] The present disclosure provides an induced voltage suppression system, comprising: an ice melting device, a ground wire, a three-phase transmission wire, and a wire transposition module;

[0006] The ground wire and the conductor transposition module are both connected to the ice melting device; the three-phase power transmission wire is connected to the conductor transposition module;

[0007] The conductor transposition module is used to change the arrangement order of each phase of the three-phase transmission conductor along the reference direction to suppress the steady-state induced overvoltage of the ground wire within the safe range of the ice-melting device; the voltage measuring device is used to measure the ground wire induced voltage, and when the ground wire induced voltage is within the safe voltage range of the ice-melting device, the ice-melting device outputs a DC voltage to melt the ground wire.

[0008] Optionally, the ice melting device comprises: a voltage management component and a gating component;

[0009] The voltage management component is connected to one end of the ground line through the gating component, and the other end of the ground line is short-circuited to the ground; the gating component is used to selectively conduct the line between the voltage management component and the ground line.

[0010] Optionally, the voltage management component includes a voltage regulator, a fuse protector and a rectifier;

[0011] The input end of the voltage regulator is connected to an AC power source, and the output end of the voltage regulator is connected to the rectifier through the fuse protector.

[0012] Optionally, the gating assembly includes a first switch, a cable, and a second switch;

[0013] The first switch, the cable and the second switch are connected in series between the output end of the rectifier and the ground line in sequence.

[0014] Optionally, the system further comprises a voltage stabilizing element;

[0015] Two ends of the voltage stabilizing element are connected to the rectifier through the first switch respectively.

[0016] Optionally, the induced voltage suppression system is applied to at least a transmission tower; the system further comprises a composite insulator and a discharge gap;

[0017] The transmission tower and the ground wire are connected via the composite insulator, and a plurality of the composite insulators are connected to both ends of the cable; wherein the discharge gap is connected in parallel to both ends of the composite insulator.

[0018] The present disclosure also provides a voltage suppression method, which is implemented based on any of the above-mentioned induction voltage suppression systems, and the method includes:

[0019] Changing the arrangement order of each phase transmission wire in the three-phase transmission wire along the reference direction;

[0020] When the ground wire induced voltage is within the safe voltage range of the ice melting device, a DC voltage is output to melt the ground wire.

[0021] Optionally, before changing the arrangement order of the transmission wires of each phase in the three-phase transmission wire along the reference direction, the method further includes:

[0022] Obtain the withstand voltage value of the composite insulator;

[0023] It is determined that the withstand voltage value of the composite insulator is greater than the DC voltage.

[0024] Optionally, when the ground wire induced voltage is within the safe voltage range of the ice melting device, outputting a DC voltage to melt the ground wire includes:

[0025] Get the ground line induction voltage threshold;

[0026] Determine that the ground line induced voltage is less than or equal to the ground line induced voltage threshold, and control the first switch and the second switch to be closed.

[0027] Optionally, the voltage suppression method further includes:

[0028] Obtain safe voltage for ice melting;

[0029] The DC voltage is controlled to be less than or equal to the ice-melting safety voltage.

[0030] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0031] The induced voltage suppression system provided by the embodiment of the present disclosure includes: an ice melting device, a ground wire, a three-phase transmission conductor, a voltage measuring device and a conductor transposition module; the ground wire and the voltage measuring device are both connected to the ice melting device; the three-phase transmission conductor is connected to the conductor transposition module; the conductor transposition module is used to change the arrangement order of each phase of the three-phase transmission conductor along the reference direction to suppress the steady-state induced overvoltage of the ground wire within the safe range of the ice melting device; the voltage measuring device is used to measure the ground wire induced voltage, and when the ground wire induced voltage is within the safe voltage range of the ice melting device, the ice melting device outputs a DC voltage to melt the ground wire. In this way, by changing the arrangement order of each phase of the three-phase transmission conductor along the reference direction, the steady-state induced overvoltage is suppressed, and then the ice melting device can work normally within the safe voltage range, which is conducive to further realizing long-distance and high-efficiency single ground wire melting. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] 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.

[0033] 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.

[0034] Figure 1 A schematic diagram of the structure of an induced voltage suppression system provided in an embodiment of the present disclosure;

[0035] Figure 2 A schematic diagram of the arrangement sequence of a three-phase transmission conductor provided in an embodiment of the present disclosure;

[0036] Figure 3A schematic diagram of the structure of an ice melting device provided in an embodiment of the present disclosure;

[0037] Figure 4 A schematic diagram of the composition structure of a composite insulator and a discharge gap provided in an embodiment of the present disclosure;

[0038] Figure 5 A schematic diagram of a flow chart of a voltage suppression method provided by an embodiment of the present disclosure;

[0039] Figure 6 A schematic diagram of a curve of a steady-state induced overvoltage before transposition of a three-phase transmission conductor provided in an embodiment of the present disclosure;

[0040] Figure 7 A schematic diagram of a curve of a steady-state induced overvoltage after transposition of a three-phase transmission line provided in an embodiment of the present disclosure.

[0041] Among them, 01, power supply; 02, transmission tower; 03, lightning protection insulation structure; 110, ice melting device; 120, ground wire; 130, three-phase transmission wire; 140, voltage measuring device; 150, wire transposition module; 160, composite insulator; 170, voltage stabilizing element; 180, discharge gap; 210, voltage management component; 220, gating component; 211, voltage regulator; 212, fuse protector; 213, rectifier; 221, first switch; 222, cable; 223, second switch. DETAILED DESCRIPTION

[0042] 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.

[0043] 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.

[0044] The induced voltage suppression system and method provided by the embodiments of the present disclosure are exemplarily described below in conjunction with the accompanying drawings.

[0045] Figure 1 This is a schematic diagram of the structure of an induced voltage suppression system provided by an embodiment of the present disclosure. Figure 1The system includes: an ice melting device 110, a ground wire 120, a three-phase transmission wire 130, a voltage measuring device 140 and a wire transposition module 150; the ground wire 120 and the voltage measuring device 140 are both connected to the ice melting device 110; the three-phase transmission wire 130 is connected to the wire transposition module 150; the wire transposition module 150 is used to change the arrangement order of each phase transmission wire in the three-phase transmission wire 130 along the reference direction, so as to suppress the steady-state induced overvoltage of the ground wire 120 within the safety range of the ice melting device 110; the voltage measuring device 140 is used to measure the ground wire induced voltage, and when the ground wire induced voltage is within the safety voltage range of the ice melting device 110, the ice melting device 110 outputs a DC voltage to melt the ground wire 120.

[0046] The three-phase transmission conductor 130 is a line for transmitting electric power, and is usually arranged below the ground wire 120. The three-phase transmission conductor 130 includes three transmission conductors of different phases (commonly known as phase lines), each of which transmits one phase of alternating current, and the three phases of the three-phase electricity differ by 120°, which ensures the balance and safety of the three-phase transmission conductor 130.

[0047] Among them, the ground wire 120 is a line used to provide grounding protection to prevent electric shock accidents and electrical faults. In addition, in practical applications, the induced voltage on the ground wire (referred to as ground wire induced voltage) usually includes a transient induced overvoltage generated by a system fault or lightning strike, and a steady-state induced overvoltage generated by the three-phase transmission wire 130 on the ground wire 120. Here, the steady-state induced overvoltage is used as an example to illustrate that when current passes through the three-phase transmission wire 130, an alternating magnetic field is generated in the surrounding space. Since the three-phase transmission wire 130 and the ground wire 120 are close to each other, electromagnetic induction (i.e. mutual induction) occurs between the two, so that the three-phase transmission wire 130 generates a continuous steady-state induced overvoltage on the ground wire 120.

[0048] Specifically, Figure 2 A schematic diagram of the arrangement sequence of a three-phase transmission line provided in an embodiment of the present disclosure is shown in FIG. Figure 2 As shown, the three-phase transmission conductor 130 may include three-phase transmission conductors A, B, and C. Taking the longitudinal direction from top to bottom as the reference direction, the three-phase transmission conductor 130 sequentially arranges the A-phase transmission conductor (represented by A), the B-phase transmission conductor (represented by B), and the C-phase transmission conductor (represented by C) along the reference direction, which is the original arrangement order of the three-phase transmission conductor 130. On this basis, the arrangement order of each phase transmission conductor in the three-phase transmission conductor 130 along the reference direction is changed through the conductor transposition module 150, including: the three-phase transmission conductor 130 sequentially arranges the C-phase transmission conductor, the A-phase transmission conductor, and the B-phase transmission conductor along the reference direction, or sequentially arranges the B-phase transmission conductor, the C-phase transmission conductor, and the A-phase transmission conductor along the reference direction, so that line crossing occurs in the three-phase transmission conductor 130.

[0049] In this way, the spatial position of the three-phase transmission conductor 130 is rearranged to ensure that each phase of the transmission conductor can occupy the same electromagnetic environment in turn at different positions, which is equivalent to the steady-state induced overvoltages generated by mutual inductance offsetting each other at different positions, balancing the electromagnetic influence of each phase of the transmission conductor on the adjacent ground wire 120, thereby effectively reducing the steady-state induced overvoltage generated by the three-phase transmission conductor 130 on the ground wire 120, so that it is suppressed within a reasonable range for the steady-state induced overvoltage, that is, within the safety range of the ice melting device, and further realizing that the ground wire induced voltage is within the safety voltage range of the ice melting device, so that the ice melting device 110 can maintain normal operation after connection without damage, thereby improving the single ice melting distance and ice melting efficiency of the ground wire.

[0050] In addition, the disclosed embodiment can reasonably select the number and position of each phase transmission wire transposition within a certain ice melting distance range, wherein the ice melting distance range refers to the length of the ground wire that needs to be melted. Specifically, for example, each phase transmission wire can be selected to transpose twice within the set ice melting distance range, and the positions of the two transpositions are different from the original position (such as Figure 2 ), the de-icing distance range, the number of times and positions of the transmission wires of each phase are transposed can be set according to the de-icing requirements of the ground wire, and are not limited here.

[0051] Exemplarily, the conductor transposition module 150 may include conventional intelligent adjustment mechanisms such as intelligent suspension devices and adaptive suspension transmission towers to automatically arrange the spatial position of the three-phase transmission conductors 130. In other embodiments, it may also be other equipment or devices with the above functions known to those skilled in the art, which are not limited here.

[0052] The induced voltage suppression system provided by the embodiment of the present disclosure includes: an ice melting device 110, a ground wire 120, a three-phase transmission wire 130 and a wire transposition module 150; the ground wire 120 and the wire transposition module 150 are both connected to the ice melting device 110; the three-phase transmission wire 130 is connected to the wire transposition module 150; the wire transposition module 150 is used to change the arrangement order of the transmission wires of each phase in the three-phase transmission wire 130 along the reference direction, so as to suppress the steady-state induced overvoltage of the ground wire 120 within the safety range of the ice melting device 110; the voltage measuring device 140 is used to measure the ground wire induced voltage, and when the ground wire induced voltage is within the safety voltage range of the ice melting device 110, the ice melting device 110 outputs a DC voltage to melt the ground wire. In this way, by using the conductor transposition module 150 to change the arrangement order of each phase of the three-phase transmission conductor 130 along the reference direction, the steady-state induced overvoltage is suppressed, and then the ice melting device 110 can work normally within the safe voltage range, which is conducive to further realizing long-distance, high-efficiency single ground wire ice melting.

[0053] In addition, the induced voltage suppression system provided by the embodiment of the present disclosure has a simple structure, reduces the difficulty of implementation, and has high practicality.

[0054] In some embodiments, Figure 3 A schematic diagram of the structure of an ice melting device provided in an embodiment of the present disclosure. Figure 1 Based on Figure 3 The ice melting device 110 includes: a voltage management component 210 and a gating component 220; the voltage management component 210 is connected to one end of the ground line 120 through the gating component 220, and the other end of the ground line 120 is short-circuited to the ground; the gating component 220 is used to selectively conduct the line between the voltage management component 210 and the ground line 120.

[0055] The voltage management component 210 is a structure for processing the input AC voltage, including but not limited to: adjusting the amplitude of the AC voltage, converting the voltage type of the AC voltage, etc., so as to achieve the voltage management function.

[0056] Specifically, when there is a need to melt the ground wire, the gating component 220 turns on the line between the voltage management component 210 and the ground wire 120, and the current or voltage (such as DC voltage) output from the voltage management component 210 can be transmitted to the ground wire 120, so that the ground wire 120 can be melted by the heat generated by the current (or voltage). Conversely, when there is no need to melt the ground wire, the gating component 220 disconnects the line between the voltage management component 210 and the ground wire 120, and the current or voltage output from the voltage management component 210 cannot be transmitted to the ground wire 120, and the ground wire 120 will not be melted.

[0057] In some embodiments, continue to refer to Figure 3 The voltage management component 210 includes a voltage regulator 211, a fuse protector 212 and a rectifier 213; the input end of the voltage regulator 211 is connected to the AC power source 01, and the output end of the voltage regulator 211 is connected to the rectifier 213 through the fuse protector 212.

[0058] Specifically, after the external AC power source 01 inputs the AC voltage, the voltage regulator 211 can automatically adjust the AC voltage according to the voltage usage requirements, so that it is stable within the set output voltage range, ensuring the stability of the voltage supply.

[0059] The fuse protector 212 is a device for cutting off the line when the AC voltage is too high. Specifically, when the AC voltage output by the voltage regulator 211 exceeds the AC voltage threshold, the fuse protector 212 determines that the AC voltage is too high, and automatically cuts off the line to protect the ice melting device 110 from damage by overvoltage, thereby improving the safety of the entire ice melting device 110.

[0060] The rectifier 213 is a device for converting AC voltage into DC voltage. Specifically, by using the rectifier 213 to convert AC voltage into DC voltage, the voltage usage requirements of the devices and circuits after the rectifier 213 are met, so that the related devices and circuits can work normally based on the DC voltage.

[0061] In this way, by adjusting the AC voltage through the voltage regulator 211 and converting the AC voltage into a DC voltage through the rectifier 213, the voltage used for melting ice can be controlled within a reasonable range to prevent the ground wire 120 from being damaged due to excessive corresponding voltage applied to it by the ice melting device.

[0062] In some embodiments, continue to refer to Figure 3 The gating component 220 includes a first switch 221 , a cable 222 and a second switch 223 ; the first switch 221 , the cable 222 and the second switch 223 are sequentially connected in series between the output end of the rectifier 213 and the ground line 120 .

[0063] The first switch 221 is a switch device used indoors, the voltage measuring device is arranged at the first switch 221, the second switch 223 is a switch device used outdoors, and the first switch 221 and the second switch 223 are electrically connected via a cable 222. Exemplarily, the first switch 221 and the second switch 223 may be single-pole double-throw switches, ice-melting switches, or other types of switch devices with switching functions.

[0064] It can be understood that the rectifier 213 generally includes two output terminals, Figure 3 It is exemplarily shown that its two output ends are respectively a positive output end (indicated by +) and a negative output end (indicated by -), and the first switch 221, the cable 222 and the second switch 223 are connected in series in sequence between each output end of the rectifier 213 and a corresponding ground line 120 to form a loop.

[0065] Specifically, taking the example that the first switch 221 and the second switch 223 are both provided with a first switching end, a second switching end and a common end, the first switching end of the first switch 221 is connected to the rectifier 213, the first switching end of the second switch 223 is connected to the cable 222, and the second switching ends of both are grounded. When the ground wire 120 needs to be de-iced, the common end of the first switch 221 and the second switch 223 is switched to connect to the first switching end (i.e. closed), and the first switch 221 and the second switch 223 are both turned on, so that the current output by the rectifier 213 flows through the ground wire 120 to de-ice it.

[0066] When there is no need to melt the ground wire 120, the common end of the first switch 221 and the second switch 223 is switched to connect to the second switch end (i.e., disconnected), so that the head end of the ground wire 120 is grounded through the second switch 223, and the end of the ground wire 120 is short-circuited to the ground, and the current output by the rectifier 213 cannot flow through the ground wire 120.

[0067] In some embodiments, continue to refer to Figure 3 The induced voltage suppression system further includes a voltage stabilizing element 170 ; both ends of the voltage stabilizing element 170 are connected to the rectifier 213 through a first switch 221 .

[0068] Among them, the voltage stabilizing element 170 is an element for stabilizing the induced voltage on the ground wire 120. Specifically, by setting the two ends of the voltage stabilizing element 170 to be connected to the rectifier 213 through a first switch 221, the voltage stabilizing element 170 is connected in parallel with the rectifier 213, that is, the voltage stabilizing element 170 is connected to the ground wire 120 corresponding to each output end of the rectifier 213. When there is an induced voltage on the ground wire 120, the voltage stabilizing element 170 can stabilize the induced voltage so that its value remains within a certain variation range, thereby realizing the coordinated conductor transposition module 150 to suppress the induced voltage of the ground wire within a set voltage range, effectively improving the induced voltage suppression effect on the ground wire 120, and ensuring the reliable and stable operation of the UHV line in harsh environments.

[0069] Exemplarily, the voltage stabilizing element 170 may be a linear regulator, a Zener diode or a switching regulator. In other embodiments, it may be other types of devices with voltage stabilizing functions known to those skilled in the art, which are not limited here.

[0070] In some embodiments, Figure 4 A schematic diagram of the structure of a composite insulator and a discharge gap provided in an embodiment of the present disclosure, combined with Figure 3 and Figure 4 The induced voltage suppression system is applied to at least the transmission tower 02; the system also includes a composite insulator 160 and a discharge gap 180; the transmission tower 02 and the ground wire 120 are connected through the composite insulator 160, and multiple composite insulators 160 are connected to both ends of the cable 222; wherein, the discharge gap 180 is connected in parallel at both ends of the composite insulator 160.

[0071] The composite insulator 160 is connected in parallel with the discharge gap 180 to provide lightning protection and electrical insulation. For example, the overall structure formed by the discharge gap 180 connected in parallel at both ends of the composite insulator 160 can be referred to as the lightning protection insulation structure 03. Figure 3It is shown that both ends of each transmission tower 02 are connected to the ground wire 120, a lightning protection insulation structure 03 is connected to the head end of the cable 222, and the remaining number of lightning protection insulation structures 03 are connected to the ends of the cable 222, and a lightning protection insulation structure 03 is provided between the transmission tower 02 and the ground wire 120.

[0072] In this way, by arranging a composite insulator 160 with a discharge gap 180 in parallel between the transmission tower 02 and the ground wire 120, the electrical insulation characteristics of the composite insulator 160 can be used to isolate the ground wire 120 from the transmission tower 02, and the ground wire 120 is suspended, thereby realizing the insulation transformation of the ground wire 120. Therefore, the DC voltage output by the rectifier 213 is only provided to the ground wire 120 for ice melting, thereby improving the ice melting effect of the ground wire 120, increasing the ice melting distance, and avoiding the problem that the DC voltage output by the rectifier 213 passes through the ground wire 120 and the transmission tower 02 in sequence to the ground, resulting in the inability to effectively melt ice.

[0073] It should be noted that the discharge gap 180 is composed of two metal rods, the head ends of the two metal rods are staggered to form a gap, and the ends of the two metal rods are respectively connected to the composite insulators 160. In lightning weather, the gap in the discharge gap 180 is easily broken down by a lightning voltage with a higher amplitude. After the breakdown phenomenon occurs, the lightning current can flow into the ground along the transmission tower 02, providing a safe transmission channel for the lightning current, thereby realizing the lightning protection effect of the discharge gap 180 on the ground wire 120.

[0074] In addition, by providing a plurality of composite insulators 160 with discharge gaps 180 in parallel and connected to both ends of the cable 222, it is also possible to effectively suppress transient induced overvoltages caused by system failures or lightning strikes during the ice melting process, limit them to a reasonable range for transient induced overvoltages, and protect the ice melting device.

[0075] On the basis of the above implementation, the embodiment of the present disclosure further provides a voltage suppression method, which is implemented based on any one of the induced voltage suppression systems provided in the above embodiments and has corresponding beneficial effects, which will not be elaborated here.

[0076] In some embodiments, Figure 5 A schematic diagram of a voltage suppression method provided by an embodiment of the present disclosure, referring to Figure 5 , the method specifically comprises the following steps:

[0077] S310. Change the arrangement order of each phase transmission wire in the three-phase transmission wire along the reference direction.

[0078] Exemplarily, the three-phase transmission conductor may include three-phase transmission conductors A, B, and C. Taking the longitudinal direction from top to bottom as the reference direction, the three-phase transmission conductors are arranged in sequence along the reference direction, namely, phase A transmission conductor, phase B transmission conductor, and phase C transmission conductor, which is the original arrangement order of the three-phase transmission conductors. On this basis, the arrangement order of each phase of the three-phase transmission conductors along the reference direction is changed through a conductor transposition module, including: arranging phase C transmission conductor, phase A transmission conductor, and phase B transmission conductor in sequence along the reference direction, or arranging phase B transmission conductor, phase C transmission conductor, and phase A transmission conductor in sequence along the reference direction, so that line crossing occurs in the three-phase transmission conductor.

[0079] Figure 6 A schematic diagram of a curve of a steady-state induced overvoltage before transposition of a three-phase transmission line provided in an embodiment of the present disclosure, Figure 7 A schematic diagram of a curve of a steady-state induced overvoltage after transposition of a three-phase transmission line provided in an embodiment of the present disclosure.

[0080] in, Figure 6 The horizontal axis X1 represents time in seconds (s), and the vertical axis Y1 represents voltage in kilovolts (kV); Figure 7 The horizontal axis X2 represents time in seconds (s), and the vertical axis Y2 represents voltage in kilovolts (kV).

[0081] Combination Figure 6 and Figure 7 It can be seen that the corresponding steady-state induced overvoltage before the three-phase transmission conductor transposition is large, while the corresponding steady-state induced overvoltage after the three-phase transmission conductor transposition is small, and the steady-state induced overvoltage is well suppressed.

[0082] S320: When the ground wire induced voltage is within the safe voltage range of the ice melting device, a DC voltage is output to melt the ground wire.

[0083] It can be understood that when a relatively high-amplitude steady-state induced overvoltage is generated in the ground wire, it affects the normal access of the ice-melting device. To this end, the embodiment of the present disclosure changes the arrangement order of the transmission wires of each phase in the three-phase transmission wire along the reference direction, so that the steady-state induced overvoltage is within the safe range of the ice-melting device, thereby achieving the purpose of suppressing the steady-state induced overvoltage and further achieving the ground wire induced voltage within the safe voltage range of the ice-melting device. At this time, an ice-melting device for outputting a DC voltage can be connected to melt the ground wire, thereby protecting the ice-melting device from damage, and further improving the single ice-melting distance and ice-melting efficiency of the ground wire.

[0084] In some embodiments, Figure 5 On the basis of, before S310, the following steps are also included:

[0085] Step 1: Obtain the withstand voltage value of the composite insulator.

[0086] Among them, the withstand voltage value of the composite insulator refers to the maximum voltage value that the composite insulator can withstand without breakdown or flashover. Once the voltage applied to the composite insulator exceeds the withstand voltage value, the composite insulator will break down or flashover.

[0087] Step 2: Determine that the withstand voltage of the composite insulator is greater than the DC voltage.

[0088] The DC voltage refers to the voltage for melting ice on the ground wire, specifically the output voltage of the rectifier. Specifically, when the withstand voltage of the composite insulator is set to be greater than the DC voltage, the melting voltage will not break down the composite insulator, ensuring the safety and stability of the entire system while ensuring that the DC voltage can only be used for high-efficiency, long-distance ice melting on the ground wire.

[0089] In some embodiments, Figure 5 On the basis of, S320 specifically includes the following steps:

[0090] Step 1: Obtain the ground line induction voltage threshold.

[0091] The ground wire induced voltage threshold is a value used to measure the magnitude of the ground wire induced voltage.

[0092] Specifically, in practical applications, a voltage measuring device can be used to measure the ground wire induced voltage, so as to further determine its magnitude in combination with the ground wire induced voltage threshold, and take targeted measures according to the determination result. For example, the ground wire induced voltage threshold can be 35 kV, 45 kV or other values, which can be set according to the safe use requirements of the ice melting device and is not limited here.

[0093] Step 2: Determine that the ground wire induced voltage is less than or equal to the ground wire induced voltage threshold, and control the first switch and the second switch to be closed.

[0094] Among them, the ground induced voltage is the value of the superposition of the steady-state induced overvoltage and the transient induced overvoltage. It can be understood that the steady-state induced overvoltage and the transient induced overvoltage are components of the ground induced voltage, and the amplitude of the transient induced overvoltage is usually higher than that of the steady-state induced overvoltage. For example, the transient induced overvoltage can be hundreds of kilovolts, and the steady-state induced overvoltage can be tens of kilovolts.

[0095] Specifically, when the ground wire induced voltage is less than or equal to the ground wire induced voltage threshold, it indicates that the value of the ground wire induced voltage is small and is within the safety range for the ground wire induced voltage, so that the ice-melting device can melt the ice on the ground wire under the premise of normal operation, then the first switch and the second switch are controlled to be closed to connect the ice-melting device, and the ice-melting device electrically heats the surface of the ground wire to solve the ice covering problem; conversely, when the ground wire induced voltage is greater than the ground wire induced voltage threshold, it indicates that the value of the ground wire induced voltage is large, so that the ice-melting device cannot melt the ice on the ground wire under the premise of normal operation, then the first switch and the second switch are controlled to be disconnected to protect the ice-melting device from being damaged by the ground wire induced voltage, thereby ensuring that the ground wire can achieve high-efficiency, long-distance single ice melting.

[0096] In some embodiments, the voltage suppression method further comprises the following steps:

[0097] Step 1: Obtain safe voltage for ice melting.

[0098] The ice-melting safety voltage is a value used to limit the DC voltage.

[0099] Specifically, by obtaining the ice-melting safety voltage, the size of the DC voltage can be further limited in combination with the ice-melting safety voltage. For example, on the basis of adjusting the AC voltage on its input side by using a voltage regulator, the DC voltage on its output side can be adjusted by using a rectifier to limit the DC voltage within the range of the ice-melting safety voltage.

[0100] Step 2: Control the DC voltage to be less than or equal to the ice-melting safety voltage.

[0101] In this way, by setting the DC voltage less than or equal to the safe ice-melting voltage, the DC voltage output by the ice-melting device can meet the ice-melting requirements of the ground wire, for example: it can ensure the ice-melting effect of the ground wire and will not damage the ground wire due to excessive DC voltage.

[0102] 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.

[0103] 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. An induced voltage suppression system, characterized in that: include: Ice melting device, ground wire, three-phase transmission conductor, voltage measuring device and conductor transposition module; The ground wire and the voltage measuring device are both connected to the ice melting device; The three-phase power transmission wire is connected to the wire transposition module; The conductor transposition module is used to change the arrangement order of each phase of the three-phase transmission conductor along the reference direction to suppress the steady-state induced overvoltage of the ground wire within the safe range of the ice-melting device; the voltage measuring device is used to measure the ground wire induced voltage, and when the ground wire induced voltage is within the safe voltage range of the ice-melting device, the ice-melting device outputs a DC voltage to melt the ground wire.

2. The induced voltage suppression system according to claim 1, characterized in that: The ice melting device comprises: a voltage management component and a gating component; The voltage management component is connected to one end of the ground line through the gating component, and the other end of the ground line is short-circuited to the ground; the gating component is used to selectively conduct the line between the voltage management component and the ground line.

3. The induced voltage suppression system according to claim 2, characterized in that: The voltage management component includes a voltage regulator, a fuse protector and a rectifier; The input end of the voltage regulator is connected to an AC power source, and the output end of the voltage regulator is connected to the rectifier through the fuse protector.

4. The induced voltage suppression system according to claim 3, characterized in that: The gating assembly includes a first switch, a cable, and a second switch; The first switch, the cable and the second switch are connected in series between the output end of the rectifier and the ground line in sequence.

5. The induced voltage suppression system according to claim 4, characterized in that: Also included are voltage stabilizing components; Two ends of the voltage stabilizing element are connected to the rectifier through the first switch respectively.

6. The induced voltage suppression system according to claim 4, characterized in that: The induced voltage suppression system is applied to at least a transmission tower; the system also includes a composite insulator and a discharge gap; The transmission tower and the ground wire are connected via the composite insulator, and a plurality of the composite insulators are connected to both ends of the cable; wherein the discharge gap is connected in parallel to both ends of the composite insulator.

7. A voltage suppression method, characterized in that: Based on the implementation of the induced voltage suppression system according to any one of claims 1 to 6, the method comprises: Changing the arrangement order of each phase transmission wire in the three-phase transmission wire along the reference direction; When the ground wire induced voltage is within the safe voltage range of the ice-melting device, a DC voltage is output to melt the ground wire.

8. The voltage suppression method according to claim 7, characterized in that: Before changing the arrangement order of each phase transmission wire in the three-phase transmission wire along the reference direction, the method further includes: Obtain the withstand voltage value of the composite insulator; It is determined that the withstand voltage value of the composite insulator is greater than the DC voltage.

9. The voltage suppression method according to claim 7, characterized in that: When the ground wire induced voltage is within the safe voltage range of the ice melting device, a DC voltage is output to melt the ground wire, including: Get the ground line induction voltage threshold; Determine that the ground line induced voltage is less than or equal to the ground line induced voltage threshold, and control the first switch and the second switch to be closed.

10. The voltage suppression method according to claim 7, characterized in that: Also includes: Obtain safe voltage for ice melting; The DC voltage is controlled to be less than or equal to the ice-melting safety voltage.

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