Topological structure of extra-high voltage building block type mobile ice melting series-parallel system

Abstract

The utility model discloses a topological structure of an extra-high voltage building block type mobile ice melting series-parallel system, and belongs to the technical field of direct current ice melting equipment. The structure comprises a plurality of building block type ice melting vehicles, each building block type ice melting vehicle comprises a rectification unit, a series-parallel connection change-over switch, a line selection switch and a wall bushing, and the alternating current side of the rectification unit of each building block type ice melting vehicle is connected to an alternating current power supply bus through a rectification transformer; and the positive (negative) poles of the direct current sides are connected with the negative (positive) poles of the direct current sides of the rectifying units of the adjacent building block type ice melting vehicle through the series-parallel change-over switches, and are connected with a line to be subjected to ice melting through the ice melting bus through the line selection switch. According to the utility model, the ice melting voltage is improved through the topological structure of the rectification units connected in series, the ice melting current is improved through the topological structure of the rectification units connected in parallel, the adaptive switching of the topology is realized through the building block type series-parallel connection of the plurality of ice melting devices, and the ice melting requirements of various line types and lengths of the long-distance power transmission line are considered; and full coverage of the ice melting capability of the ultra-high voltage transmission line is realized.

Description

Technical Field

[0001] This utility model belongs to the technical field of DC ice melting equipment, specifically relating to a topology of an ultra-high voltage modular mobile ice melting series-parallel system. Background Technology

[0002] Line icing leading to line breaks and tower collapses is a major factor affecting power transmission during the winter and spring seasons. In recent years, winter snow and ice storms have become increasingly frequent, with ice damage affecting multiple voltage levels, numerous lines, and a wide geographical distribution. Therefore, there is an urgent need to improve de-icing capabilities to ensure the safe operation of equipment. DC de-icing involves connecting the line to the output side of the equipment, utilizing the capacity generated by the DC current in the line to melt the ice. Due to the lower DC impedance in the line, DC de-icing generates a larger current and more heat in the same amount of time at the same voltage level, making it a currently preferred method for line de-icing.

[0003] DC de-icing devices are classified into fixed, mobile, and cabinet-type according to their deployment. Fixed devices have high power, can de-ice various line types, and have long de-icing distances, with fixed wiring configurations. However, their overall cost is high, the de-icing range is fixed, and the efficiency is relatively poor. They are mainly used in 500kV lines. Mobile devices can achieve de-icing in multiple scenarios and are easy to move. They are mainly used in 220kV and below lines, but are currently limited by capacity, current, and voltage, and cannot meet the de-icing needs of 500kV lines. Cabinet-type devices have the smallest capacity, current, and voltage, and are used in 35kV and below lines. Because 500kV lines are long, have large wire diameters, and have many branches, the requirements for the current, voltage, and capacity of the de-icing device are high. Even with appropriate modifications to the control and protection systems and parallel use, existing mobile de-icing devices still cannot meet the de-icing needs of the entire 500kV line. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this utility model provides a modular mobile de-icing series-parallel system topology for ultra-high voltage and extra-high voltage transmission lines. The de-icing voltage is increased by connecting rectifier units in series, and the de-icing current is increased by connecting rectifier units in parallel. Multiple de-icing devices are connected in a modular series-parallel manner to achieve full coverage of de-icing capacity for ultra-high voltage and extra-high voltage transmission lines.

[0005] The present invention adopts the following technical solution.

[0006] This invention provides a topology for an ultra-high voltage modular mobile ice-melting series-parallel system, comprising several modular mobile ice-melting vehicles.

[0007] Each modular ice-melting vehicle includes a rectifier unit, a line selection switch, a series-parallel switching switch, and a wall bushing. The AC side of the rectifier unit is connected to the AC power bus via a rectifier transformer. The positive and negative DC sides are connected to the corresponding DC sides of the rectifier units of adjacent modular ice-melting vehicles via a series-parallel switching switch. The rectifier unit is then connected to the line to be melted via the wall bushing, the ice-melting bus, and the line ice-melting switch in sequence through the line selection switch.

[0008] Preferably, each modular ice-melting truck rectifier unit uses a thyristor six-pulse rectifier, and the two thyristors of each phase are connected to the corresponding phase output of the rectifier transformer through a wall bushing.

[0009] Preferably, each series-parallel switching switch, line selection switch, and line de-icing knife switch is configured as an isolating switch. Adjacent modular de-icing vehicles are connected through series-parallel switching switches. The line selection switch of each phase is connected to the de-icing busbar of the corresponding phase through the wall bushing of each phase. The de-icing busbar of each phase is connected to the line to be de-iced through the line de-icing knife switch of the corresponding phase.

[0010] Preferably, the series-parallel switching switch between adjacent modular ice-melting vehicles is set to open, the rectifier unit is connected in parallel with the rectifier unit of the adjacent modular ice-melting vehicle, and the two adjacent modular ice-melting vehicles are connected in parallel.

[0011] Preferably, when the rectifier unit is connected in parallel with the rectifier unit of the adjacent modular ice-melting vehicle, the positive DC terminal of the rectifier unit is connected to the positive DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle, and the negative DC terminal of the rectifier unit is connected to the negative DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle.

[0012] Preferably, when the rectifier unit is connected in parallel with the rectifier unit of the adjacent modular ice-melting vehicle, the line selection switches corresponding to the positive and negative poles of the rectifier unit and the adjacent modular ice-melting vehicle rectifier unit are all closed. The line selection switches closed at the positive poles of the rectifier unit and the adjacent modular ice-melting vehicle rectifier unit are consistent, and the line selection switches closed at the negative poles are consistent. Furthermore, the positive and negative poles of the rectifier unit and the adjacent modular ice-melting vehicle rectifier unit are all connected to the same pair of busbars of the ice-melting busbar.

[0013] Preferably, the series-parallel switching switch between adjacent modular ice-melting vehicles is set to closed when it is open, and the rectifier unit is connected in series with the rectifier unit of the adjacent modular ice-melting vehicle, and the two adjacent modular ice-melting vehicles are connected in series.

[0014] Preferably, when the rectifier unit is connected in series with the rectifier unit of the adjacent modular ice-melting vehicle, the positive DC terminal of the rectifier unit is connected to the negative DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle, and the negative DC terminal of the rectifier unit is connected to the positive DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle.

[0015] Preferably, when the rectifier unit is connected in series with the rectifier unit of the adjacent modular ice-melting vehicle, the line selection switch corresponding to the positive terminal of the rectifier unit is closed, the line selection switch corresponding to the negative terminal of the adjacent modular ice-melting vehicle rectifier unit is closed, the line selection switch closed at the positive terminal of the rectifier unit is of a different phase from the line selection switch closed at the negative terminal of the adjacent modular ice-melting vehicle rectifier unit, the remaining line selection switches of the rectifier unit and the adjacent modular ice-melting vehicle rectifier unit are all open, and the positive and negative terminals of the rectifier unit and the adjacent modular ice-melting vehicle rectifier unit are connected to the busbars of different phases in the ice-melting busbar.

[0016] Preferably, the de-icing busbar is connected to the line to be de-iced via a line de-icing switch, and the de-icing switches of any corresponding line to the three-phase line to be de-iced are closed to de-ic the three-phase line.

[0017] The beneficial effects of this utility model are as follows, compared with the prior art:

[0018] This invention improves the de-icing voltage through a topology structure with rectifier units connected in series and improves the de-icing current through a topology structure with rectifier units connected in parallel. Multiple de-icing devices can be connected in series and parallel in a modular manner to achieve adaptive switching of the topology, taking into account the de-icing needs of various line types and lengths of long-distance transmission lines, and achieving full coverage of de-icing capacity for ultra-high voltage transmission lines. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the topology of an ultra-high voltage modular mobile ice-melting series-parallel system;

[0020] Figure 2 This is a schematic diagram of the topology of two parallel systems for ultra-high voltage modular mobile ice melting.

[0021] Figure 3 This is a schematic diagram of the topology of two series-connected ultra-high voltage modular mobile ice melting systems.

[0022] Figure 4 This is a schematic diagram of the system topology of ultra-high voltage modular mobile ice melting system, which connects two parts in series and then in parallel. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1 As shown, Embodiment 1 of the present invention provides a topology structure for an ultra-high voltage modular mobile ice-melting series-parallel system, comprising:

[0025] Each modular ice-melting vehicle 10 includes a rectifier unit 4, a line selection switch 5, a series-parallel switching switch 6, and a wall bushing 3. The AC side of the rectifier unit 4 is connected to the AC power bus 1 through the rectifier transformer 2. The DC positive and DC negative terminals are connected to the corresponding DC terminals of the rectifier units of adjacent modular ice-melting vehicles through the series-parallel switching switch 6, and are connected to the line to be melted 9 through the wall bushing 3, the ice-melting bus 7, and the line ice-melting switch 8 in sequence through the line selection switch 5.

[0026] Preferably, each modular ice-melting vehicle 10 rectifier unit 4 adopts a thyristor six-pulse rectifier, and the two thyristors of each phase are connected to the corresponding phase output by the rectifier transformer 2 through the wall bushing 3.

[0027] Each series-parallel switching switch 6, line selection switch 5, and line de-icing knife switch 8 is set as an isolating switch. Adjacent modular de-icing vehicles are connected through the series-parallel switching switch 6. The line selection switch 5 of each phase is connected to the de-icing busbar 7 of the corresponding phase through the wall bushing 3 of each phase. The de-icing busbar 7 of each phase is connected to the line to be de-iced 9 through the line de-icing knife switch 8 of the corresponding phase.

[0028] The series-parallel switching switch 6 between adjacent modular ice-melting trucks is set to open, and the rectifier unit 4 is connected in parallel with the rectifier unit of the adjacent modular ice-melting truck. The two adjacent modular ice-melting trucks are connected in parallel.

[0029] When rectifier unit 4 is connected in parallel with the rectifier unit of the adjacent modular ice-melting vehicle, the positive DC terminal of rectifier unit 4 is connected to the positive DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle, and the negative DC terminal of rectifier unit 4 is connected to the negative DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle.

[0030] When rectifier unit 4 is connected in parallel with the rectifier unit of the adjacent modular ice-melting vehicle, the line selection switches 5 corresponding to the positive and negative DC terminals of rectifier unit 4 and the adjacent modular ice-melting vehicle rectifier unit are all closed. The line selection switches 5 closed for the positive DC terminal of rectifier unit 4 and the negative DC terminal of the adjacent modular ice-melting vehicle rectifier unit are the same, and the line selection switches 5 closed for the negative DC terminal are the same. Furthermore, the positive and negative DC terminals of rectifier unit 4 and the adjacent modular ice-melting vehicle rectifier unit are all connected to the same pair of busbars of the ice-melting busbar 7.

[0031] like Figure 2As shown, two adjacent modular ice-melting trucks are connected in parallel. The positive DC side of the rectifier unit 4 and the rectifier unit of the adjacent modular ice-melting truck are both closed by selecting the line selection switch 5 corresponding to phase A. The negative DC side of the rectifier unit 4 and the rectifier unit of the adjacent modular ice-melting truck are both closed by selecting the line selection switch 5 corresponding to phase B. The line selection switches 5 closed by the positive DC side of the rectifier unit 4 and the rectifier unit of the adjacent modular ice-melting truck are the same, and the line selection switches 5 closed by the negative DC side are the same. The positive DC side of the rectifier unit 4 and the negative DC side of the rectifier unit of the adjacent modular ice-melting truck are respectively connected to the phase A and phase B buses in the ice-melting busbar 7.

[0032] Preferably, the series-parallel switching switch 6 between adjacent modular ice-melting vehicles is set to be closed when it is open, and the rectifier unit 4 is connected in series with the rectifier unit of the adjacent modular ice-melting vehicle, and the two adjacent modular ice-melting vehicles are connected in series.

[0033] When rectifier unit 4 is connected in series with the rectifier unit of the adjacent modular ice-melting vehicle, the positive DC terminal of rectifier unit 4 is connected to the negative DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle, and the negative DC terminal of rectifier unit 4 is connected to the positive DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle.

[0034] When rectifier unit 4 is connected in series with the rectifier unit of the adjacent modular ice-melting vehicle, the line selection switch 5 corresponding to the positive DC terminal of rectifier unit 4 is closed, and the line selection switch 5 corresponding to the negative DC terminal of the adjacent modular ice-melting vehicle rectifier unit is closed. The line selection switch 5 closed at the positive DC terminal of rectifier unit 4 is not in the same phase as the line selection switch 5 closed at the negative DC terminal of the adjacent modular ice-melting vehicle rectifier unit. All other line selection switches 5 of rectifier unit 4 and the adjacent modular ice-melting vehicle rectifier unit are open, and the positive DC terminal and the negative DC terminal of rectifier unit 4 and the adjacent modular ice-melting vehicle rectifier unit are connected to the busbars of different phases in the ice-melting busbar 7.

[0035] like Figure 3 As shown, two adjacent modular ice-melting vehicles are connected in series. The positive terminal of the DC side of the rectifier unit 4 is closed to select the line selection switch 5 corresponding to phase A. The negative terminal of the DC side of the rectifier unit of the adjacent modular ice-melting vehicle is closed to select the line selection switch 5 corresponding to phase B. The positive terminal of the DC side of the rectifier unit 4 is connected to the phase A bus in the ice-melting busbar 7, and the negative terminal of the DC side of the rectifier unit of the adjacent modular ice-melting vehicle is connected to the phase B bus in the ice-melting busbar 7.

[0036] Preferably, the de-icing busbar 7 is connected to the line 9 to be de-iced via the line de-icing switch 8, and the line de-icing switches 8 corresponding to any three-phase line 9 to be de-iced are closed to de-ic the three-phase line 9.

[0037] like Figure 4 As shown, Embodiment 2 of the present invention provides a topology of four ultra-high voltage modular mobile ice-melting series-parallel systems, including:

[0038] Four modular ice-melting trucks are connected in series and parallel. Series connection increases the ice-melting voltage, while parallel connection increases the ice-melting current. The AC side of the rectifier unit of each modular ice-melting truck is connected to the AC power bus via a rectifier transformer. The positive (negative) terminals of the DC side are connected to the negative (positive) DC side of the rectifier unit of the adjacent modular ice-melting truck via a series-parallel switching switch, and are connected to the line to be melted via the ice-melting bus via a line selection switch.

[0039] Each of the modular ice-melting truck rectifier units uses a thyristor six-pulse rectifier.

[0040] Preferably, the series-parallel switching of the rectifier unit is achieved by using a series-parallel switching switch to switch the opening and closing states.

[0041] Preferably, when the rectifier unit is connected in parallel with the rectifier unit of the adjacent modular ice-melting vehicle, the series-parallel switching switch between the positive (negative) terminal of the DC side of the rectifier unit and the positive (negative) terminal of the DC side of the adjacent modular ice-melting vehicle rectifier unit is opened.

[0042] Preferably, when the rectifier unit is connected in series with the rectifier unit of the adjacent modular ice-melting vehicle, the series-parallel switching switch between the positive (negative) terminal of the DC side of the rectifier unit and the negative (positive) terminal of the DC side of the adjacent modular ice-melting vehicle rectifier unit is closed.

[0043] Preferably, all line selection switches on the series pole side of the rectifier unit are disconnected, and the line selection switches on the parallel pole side of the rectifier unit select the corresponding phase switch to be closed according to the line to be de-iced, so as to de-ic the three-phase lines respectively.

[0044] The beneficial effects of this utility model are as follows, compared with the prior art:

[0045] This invention improves the de-icing voltage through a topology structure with rectifier units connected in series and improves the de-icing current through a topology structure with rectifier units connected in parallel. Multiple de-icing devices can be connected in series and parallel in a modular manner to achieve adaptive switching of the topology, taking into account the de-icing needs of various line types and lengths of long-distance transmission lines, and achieving full coverage of de-icing capacity for ultra-high voltage transmission lines.

[0046] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A topology of an ultra-high voltage modular mobile ice-melting series-parallel system, comprising several modular mobile ice-melting vehicles, characterized in that: Each modular ice-melting vehicle includes a rectifier unit, a line selection switch, a series-parallel switching switch, and a wall bushing. The AC side of the rectifier unit is connected to the AC power bus via a rectifier transformer. The positive and negative DC sides are connected to the corresponding DC sides of the rectifier units of adjacent modular ice-melting vehicles via a series-parallel switching switch. The rectifier unit is then connected to the line to be melted via the wall bushing, the ice-melting bus, and the line ice-melting switch in sequence through the line selection switch.

2. The topology of the ultra-high voltage modular mobile ice-melting series-parallel system according to claim 1, characterized in that: Each modular ice-melting truck rectifier unit uses a thyristor six-pulse rectifier, with two thyristors in each phase connected to the corresponding phase output of the rectifier transformer via a through-wall bushing.

3. The topology of the ultra-high voltage modular mobile ice-melting series-parallel system according to claim 1, characterized in that: Each series-parallel switching switch, line selection switch, and line de-icing knife switch is set as an isolating switch. Adjacent modular de-icing trucks are connected through series-parallel switching switches. The line selection switch of each phase is connected to the de-icing busbar of the corresponding phase through the wall bushing of each phase. The de-icing busbar of each phase is connected to the line to be de-iced through the line de-icing knife switch of the corresponding phase.

4. The topology of the ultra-high voltage modular mobile ice-melting series-parallel system according to claim 1, characterized in that... The series-parallel switching switch between adjacent modular ice-melting trucks is set to open, and the rectifier unit is connected in parallel with the rectifier unit of the adjacent modular ice-melting truck. The two adjacent modular ice-melting trucks are connected in parallel.

5. The topology of an ultra-high voltage modular mobile ice-melting series-parallel system according to claim 4, characterized in that: When the rectifier unit is connected in parallel with the rectifier unit of the adjacent modular ice-melting vehicle, the positive DC terminal of the rectifier unit is connected to the positive DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle, and the negative DC terminal of the rectifier unit is connected to the negative DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle.

6. The topology of an ultra-high voltage modular mobile ice-melting series-parallel system according to claim 5, characterized in that: When the rectifier unit is connected in parallel with the rectifier unit of the adjacent modular ice-melting vehicle, the line selection switches corresponding to the positive and negative poles of the rectifier unit and the adjacent modular ice-melting vehicle rectifier unit are all closed. The line selection switches closed for the positive poles of the rectifier unit and the adjacent modular ice-melting vehicle rectifier unit are consistent, and the line selection switches closed for the negative poles are consistent. Furthermore, the positive and negative poles of the rectifier unit and the adjacent modular ice-melting vehicle rectifier unit are all connected to the same pair of busbars of the ice-melting busbar.

7. The topology of an ultra-high voltage modular mobile ice-melting series-parallel system according to claim 1, characterized in that: The series-parallel switching switch between adjacent modular ice-melting trucks is set to closed when it is open. The rectifier unit is connected in series with the rectifier unit of the adjacent modular ice-melting truck, and the two adjacent modular ice-melting trucks are connected in series.

8. The topology of an ultra-high voltage modular mobile ice-melting series-parallel system according to claim 7, characterized in that: When the rectifier unit is connected in series with the rectifier unit of the adjacent modular ice-melting vehicle, the positive DC terminal of the rectifier unit is connected to the negative DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle, and the negative DC terminal of the rectifier unit is connected to the positive DC terminal of the rectifier unit of the adjacent modular ice-melting vehicle.

9. The topology of an ultra-high voltage modular mobile ice-melting series-parallel system according to claim 8, characterized in that: When the rectifier unit is connected in series with the rectifier unit of the adjacent modular ice-melting truck, the line selection switch corresponding to the positive terminal of the rectifier unit is closed, and the line selection switch corresponding to the negative terminal of the adjacent modular ice-melting truck rectifier unit is closed. The line selection switch closed at the positive terminal of the rectifier unit is not in the same phase as the line selection switch closed at the negative terminal of the adjacent modular ice-melting truck rectifier unit. All other line selection switches of the rectifier unit and the adjacent modular ice-melting truck rectifier unit are open, and the positive and negative terminals of the rectifier unit and the adjacent modular ice-melting truck rectifier unit are connected to the busbars of different phases in the ice-melting busbar.

10. The topology of an ultra-high voltage modular mobile ice-melting series-parallel system according to claim 1, characterized in that: The de-icing busbar is connected to the line to be de-iced via a line de-icing switch. The de-icing switch is set to close any corresponding line of the three-phase line to be de-iced, and the ice on the three-phase line is de-iced.

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