CN116131191A - Uninterrupted DC ice melting method for extra-high voltage DC line overhead ground wire - Google Patents
Uninterrupted DC ice melting method for extra-high voltage DC line overhead ground wire Download PDFInfo
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- CN116131191A CN116131191A CN202211605912.2A CN202211605912A CN116131191A CN 116131191 A CN116131191 A CN 116131191A CN 202211605912 A CN202211605912 A CN 202211605912A CN 116131191 A CN116131191 A CN 116131191A
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- ice melting
- ground wire
- overhead ground
- deicing
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G7/00—Overhead installations of electric lines or cables
- H02G7/16—Devices for removing snow or ice from lines or cables
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
- H02G1/02—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for overhead lines or cables
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Abstract
The invention discloses a uninterrupted DC deicing method for an extra-high voltage DC line overhead ground wire, which comprises the steps of determining a deicing section of the extra-high voltage DC line overhead ground wire; carrying out short circuit transformation and insulation transformation on the overhead ground wire of the ice melting section; connecting an overhead ground wire of the deicing section with a direct-current deicing device to perform direct-current deicing; and after the ice melting is finished, disconnecting the direct-current ice melting device from the overhead ground wire, and finishing the uninterrupted direct-current ice melting of the overhead ground wire of the extra-high voltage direct-current line. According to the invention, the ice melting of the overhead ground wire can be realized in the running state of the wire, the risk of faults of the ice coating of the extra-high voltage ground wire is effectively reduced, and the safe running of a power grid is kept; the insulation transformation and the short circuit transformation of the invention can not influence the normal operation and the function of the circuit, and have small influence; the invention suppresses the induced voltage and has higher safety; the method has smaller coverage, so the ice melting capacity is small and the cost is lower; therefore, the invention has high reliability, good practicability, convenience and rapidness.
Description
Technical Field
The invention belongs to the field of electrical automation, and particularly relates to a uninterrupted DC ice melting method for an extra-high voltage DC line overhead ground wire.
Background
Along with the development of economic technology and the improvement of living standard of people, electric energy becomes an indispensable secondary energy source in the production and living of people, and brings endless convenience to the production and living of people. Therefore, ensuring stable and reliable supply of electric energy becomes one of the most important tasks of the electric power system.
Currently, an extra-high voltage power grid is gradually developed into a backbone grid of the whole power grid; therefore, the transmission reliability of the extra-high voltage power grid is particularly important. The distance of the transmission line of the ultra-high voltage power grid is extremely long, and the climate conditions of the region are complex, so that serious icing is extremely easy to cause. In addition, the overhead ground wire of the extra-high voltage direct current line has no load current, so the thickness of the ice coating is generally thicker than that of the transmission wire, and the overhead ground wire is extremely easy to break, fall down or sag too much, thereby causing accidents such as discharging of the wire to the ground wire, and seriously affecting the safe and stable operation of the extra-high voltage direct current line.
However, for the ice melting scheme of the overhead ground wire of the extra-high voltage direct current line, an overhead ground wire full-insulation scheme is generally adopted, namely, after the overhead ground wire is fully insulated, an ice melting loop is formed through the ground wire, so that the melting of the overhead ground wire is realized; however, such a scheme requires a power failure to the wire during ice melting, which affects the normal supply of the load. In addition, research institutions research an externally wound type ground wire and an embedded type ground wire, the externally wound type ground wire is used for externally winding an insulation wire for heating on the surface of the ground wire, the embedded type ground wire is used for embedding the insulation wire for heating in a ground wire core wire, and the purpose of heating and deicing is achieved by applying voltage to the insulation wire to generate current, but the insulation wire is low in insulation strength, easy to break down, difficult to find a fault point after break down, and severely limited in practical application;
disclosure of Invention
The invention aims to provide the uninterrupted direct current deicing method for the extra-high voltage direct current line overhead ground wire, which has high reliability, good practicability, convenience and quickness.
The uninterrupted DC deicing method for the extra-high voltage DC line overhead ground wire provided by the invention comprises the following steps of:
s1, determining an ice melting section of an extra-high voltage direct current line overhead ground wire;
s2, carrying out short circuit transformation on the overhead ground wire of the ice melting section;
s3, insulating and reforming the overhead ground wire of the ice melting section;
s4, connecting the overhead ground wire of the ice melting section with a direct-current ice melting device to perform direct-current ice melting;
s5, after the deicing is completed, disconnecting the direct-current deicing device from the overhead ground wire, and finally completing uninterrupted direct-current deicing of the overhead ground wire of the extra-high voltage direct-current line.
And the ice melting section in the step S1 is a section between two adjacent towers of the extra-high voltage direct current line.
And step S2, carrying out short circuit transformation on the overhead ground wire of the ice melting section, and specifically comprising the following steps:
shorting the overhead ground wire at the first iron tower side in the ice melting section, and grounding the short contact;
in the ice melting section, a down lead is adopted to lead the overhead ground wire at the side of the second iron tower to the bottom of the tower; and the down lead at the side of the second iron tower is connected with the direct-current deicing device when the direct-current deicing is carried out on the line, and is directly grounded when the line works normally.
The short-circuit point is grounded, specifically, the short-circuit point is grounded through the tower body of the iron tower.
The short circuit transformation is permanent short circuit transformation or temporary short circuit transformation.
In the step S3, insulation transformation is performed on the overhead ground wire of the deicing section, specifically, insulation transformation is performed on the overhead ground wire of the deicing section, the overhead ground wire of the deicing section is insulated from the iron tower through an insulator, and meanwhile, the overhead ground wire of the deicing section is insulated from the overhead ground wires of other sections of the overhead line through the insulator; the insulator is used for insulating the deicing line from the iron tower during direct current deicing, insulating the deicing line from overhead ground wires of other sections during direct current deicing, and preventing lightning strike from penetrating to the ground during normal operation of the overhead ground wires.
The insulation transformation is permanent insulation transformation or temporary insulation transformation.
The direct-current ice melting device specifically comprises a power supply module, an ice melting transformer module, an ice melting standby power supply module, an ice melting switch module, an ice melting rectifying module and an induced voltage suppression module; the power supply module, the ice melting transformer module, the ice melting switch module and the ice melting rectification module are sequentially connected in series, the output end of the ice melting standby power supply module is connected with the output end of the ice melting transformer module in parallel, and the port of the induced voltage suppression module is connected with the output end of the ice melting rectification module in parallel; the power supply module is used for providing a power supply for ice melting, and after the output power supply is reduced by the ice melting transformer module, the power supply is input to the ice melting rectifying module by the ice melting switch module, and the ice melting rectifying module converts the received ice melting electric energy into direct current electric energy and outputs the direct current electric energy to the outside for ice melting operation; the ice melting standby power supply module is used for providing auxiliary standby ice melting power supply when the power supply module cannot supply power; the induced voltage suppression module is used for suppressing the induced voltage on the ground wire of the ice melting section in the ice melting process, so that the safety of the ice melting process is ensured.
The induced voltage suppression module comprises a voltage suppression negative electrode resistor, a voltage suppression negative electrode capacitor, a voltage suppression negative electrode voltage limiter, a voltage suppression positive electrode resistor, a voltage suppression positive electrode capacitor and a voltage suppression positive electrode voltage limiter; the voltage suppression negative electrode resistor, the voltage suppression negative electrode capacitor and the voltage suppression negative electrode voltage limiter are connected in parallel, one end of the parallel connection is grounded, and the other end of the parallel connection is connected with an output negative electrode of the ice melting rectification module; the voltage suppression positive electrode resistor, the voltage suppression positive electrode capacitor and the voltage suppression positive electrode voltage limiter are connected in parallel, one end of the voltage suppression positive electrode resistor, the voltage suppression positive electrode capacitor and the voltage suppression positive electrode voltage limiter are grounded after being connected in parallel, and the other end of the voltage suppression positive electrode resistor, the voltage suppression positive electrode capacitor and the voltage suppression positive electrode voltage limiter are connected with the output positive electrode of the ice melting rectifying module.
The uninterrupted direct current deicing method for the extra-high voltage direct current line overhead ground wire can realize deicing of the overhead ground wire in a wire running state, effectively reduce the risk of fault of the extra-high voltage ground wire icing, and keep the safe running of a power grid; the insulation transformation and the short circuit transformation related in the method can not influence the normal operation and the function of the circuit, and have small influence; the ice melting process of the method of the invention suppresses the induced voltage, and has higher safety; the method has smaller coverage, so the ice melting capacity is small and the cost is lower; therefore, the invention has high reliability, good practicability, convenience and rapidness.
Drawings
FIG. 1 is a schematic flow chart of the method of the present invention.
Fig. 2 is a schematic diagram of the ice melting process of the present invention.
Fig. 3 is a schematic diagram of functional modules of the dc ice melting apparatus of the present invention.
Fig. 4 is a circuit schematic diagram of the induced voltage suppression module according to the present invention.
Detailed Description
The process flow diagram of the present invention is shown in FIG. 1: the uninterrupted DC deicing method for the extra-high voltage DC line overhead ground wire provided by the invention comprises the following steps of:
s1, determining an ice melting section of an extra-high voltage direct current line overhead ground wire; the ice melting section is a section between two adjacent towers of the extra-high voltage direct current circuit;
s2, carrying out short circuit transformation on the overhead ground wire of the ice melting section; the method specifically comprises the following steps:
shorting the overhead ground wire at the first iron tower side in the ice melting section, and grounding the short contact; the short-circuit point is grounded through the tower body of the iron tower;
in the ice melting section, a down lead is adopted to lead the overhead ground wire at the side of the second iron tower to the bottom of the tower; the down lead at the side of the second iron tower is connected with a direct-current deicing device when the direct-current deicing is carried out on the line, and is directly grounded when the line works normally;
the short circuit transformation can be permanent short circuit transformation or temporary short circuit transformation;
s3, insulating and reforming the overhead ground wire of the ice melting section; the method comprises the steps of performing insulation transformation on the overhead ground wire of the deicing section, insulating the overhead ground wire of the deicing section from an iron tower through an insulator, and insulating the overhead ground wire of the deicing section from the overhead ground wires of other sections of the overhead line through the insulator; the insulator is used for insulating the deicing line from the iron tower during direct current deicing, insulating the deicing line from overhead ground wires of other sections during direct current deicing, and preventing lightning strike from penetrating to the ground during normal operation of the overhead ground wires;
the insulation transformation can be permanent insulation transformation or temporary insulation transformation;
s4, connecting the overhead ground wire of the ice melting section with a direct-current ice melting device to perform direct-current ice melting;
s5, after the deicing is completed, disconnecting the direct-current deicing device from the overhead ground wire, and finally completing uninterrupted direct-current deicing of the overhead ground wire of the extra-high voltage direct-current line.
Fig. 2 is a schematic diagram of the ice melting process according to the present invention: FIG. 2 is a process of simultaneously melting ice in two sections; wherein, the # N-L section to the # N section are the first section, and the # N section to the # N+L section are the second section;
in the first section, the overhead ground wire is insulated and reformed through an insulator (in the figure, a capacitor is exemplified), meanwhile, short circuit is carried out through a short circuit wire (thick black wire in the figure) in a # N-L section, and meanwhile, the short circuit wire is grounded at a short circuit point; the short circuit transformation is not carried out in the # N section, but the overhead ground wire is led to the bottom of the tower through the down wire, so that the overhead ground wire is conveniently connected with the direct current ice melting device; similarly, in the second section, shorting is performed in #n+l section by shorting lines (thick black lines in the drawing) while grounding is performed in the shorting point; the # N section is not subjected to short circuit transformation, but only the overhead ground wire is led to the bottom of the tower through the down wire, so that the overhead ground wire is conveniently connected with the direct-current deicing device.
When the ice is melted, the direct-current ice melting device is started, a loop is formed through the two overhead ground wires of the first section or the two overhead ground wires of the second section, and ice melting of each section is implemented.
Fig. 3 is a schematic diagram of functional modules of the dc ice melting device according to the present invention: the direct-current ice melting device comprises a power supply module 1, an ice melting transformer module 2, an ice melting standby power supply module 5, an ice melting switch module 3, an ice melting rectification module 4 and an induced voltage suppression module 6; the power supply module, the ice melting transformer module, the ice melting switch module and the ice melting rectification module are sequentially connected in series, the output end of the ice melting standby power supply module is connected with the output end of the ice melting transformer module in parallel, and the port of the induced voltage suppression module is connected with the output end of the ice melting rectification module in parallel; the power supply module is used for providing a power supply for ice melting, and after the output power supply is reduced by the ice melting transformer module, the power supply is input to the ice melting rectifying module by the ice melting switch module, and the ice melting rectifying module converts the received ice melting electric energy into direct current electric energy and outputs the direct current electric energy to the outside for ice melting operation; the ice melting standby power supply module is used for providing auxiliary standby ice melting power supply when the power supply module cannot supply power; the induced voltage suppression module is used for suppressing the induced voltage on the ground wire of the ice melting section in the ice melting process, so that the safety of the ice melting process is ensured.
Fig. 4 is a schematic circuit diagram of an induced voltage suppression module according to the present invention: the induced voltage suppression module comprises a voltage suppression negative electrode resistor, a voltage suppression negative electrode capacitor, a voltage suppression negative electrode voltage limiter, a voltage suppression positive electrode resistor, a voltage suppression positive electrode capacitor and a voltage suppression positive electrode voltage limiter; the voltage suppression negative electrode resistor, the voltage suppression negative electrode capacitor and the voltage suppression negative electrode voltage limiter are connected in parallel, one end of the parallel connection is grounded, and the other end of the parallel connection is connected with an output negative electrode of the ice melting rectification module; the voltage suppression positive electrode resistor, the voltage suppression positive electrode capacitor and the voltage suppression positive electrode voltage limiter are connected in parallel, one end of the voltage suppression positive electrode resistor, the voltage suppression positive electrode capacitor and the voltage suppression positive electrode voltage limiter are grounded after being connected in parallel, and the other end of the voltage suppression positive electrode resistor, the voltage suppression positive electrode capacitor and the voltage suppression positive electrode voltage limiter are connected with the output positive electrode of the ice melting rectifying module.
The method of the invention is further described in connection with one embodiment as follows:
a Lewis ice coating section of a certain + -800 kV extra-high voltage direct current wire is positioned in a #1507- #1514 section, the length is 3km, the ground wire model is LBGJ-150-20AC, and the ice melting current range is 280A-470A after the ice melting curve is checked. The method for melting ice is adopted for the section ground wire, a 10kV distribution line is led to the lower part of a tower nearby, a #1510 tower is led to be taken as an example, an ice melting device is arranged below the #1510 tower, two ground wires are led to the lower part of the tower at the #1510 tower, insulation transformation is carried out on the #1507- #1510 section and the #1510- #1514 section respectively through a gap insulator, and the two ground wires are grounded in a short circuit mode at the tail end of each section. Determining parameters of an ice melting device according to the length of ground wire ice melting, and taking an ice melting current 400A and a required ice melting voltage 600V when the ice is melted in the section #1507- # 1510; when the sections #1507- #1510 are subjected to ice melting, the ice melting current 400A is taken, the required ice melting voltage is 700V, the rated capacity of the ice melting rectifying device is designed to be 280kW, the output voltage is 700V, the output current is 400A, the ice melting voltage transformation device is 300kVA, ice melting can be respectively implemented on the two sections, the rated capacity of the ice melting rectifying device is designed to be 560kW, the output voltage is 700V, the output current is 800A, the ice melting voltage transformation device is 600kVA, the 2 sections can be connected in parallel and ice melting can be simultaneously implemented, and the capacity of the standby generator set can be equal in capacity according to the ice melting voltage transformation device. According to simulation calculation, the induced voltage of the circuit is about 1kV, the operation overvoltage is about 50kV, the resistance value of the positive electrode resistor and the negative electrode resistor in the induced voltage suppression component is 8.5kΩ, the capacitance value of the positive electrode capacitor is 400 mu F, the action voltage of the positive electrode voltage limiter is 1500V, the induced voltage or the operation overvoltage exists in the circuit in the ice melting process, and the induced voltage can be effectively limited, so that the equipment and the personal safety are protected.
Claims (9)
1. An uninterrupted DC deicing method for an extra-high voltage DC line overhead ground wire comprises the following steps:
s1, determining an ice melting section of an extra-high voltage direct current line overhead ground wire;
s2, carrying out short circuit transformation on the overhead ground wire of the ice melting section;
s3, insulating and reforming the overhead ground wire of the ice melting section;
s4, connecting the overhead ground wire of the ice melting section with a direct-current ice melting device to perform direct-current ice melting;
s5, after the deicing is completed, disconnecting the direct-current deicing device from the overhead ground wire, and finally completing uninterrupted direct-current deicing of the overhead ground wire of the extra-high voltage direct-current line.
2. The uninterruptible direct current deicing method for the extra-high voltage direct current line overhead ground wire according to claim 1, wherein the deicing section in the step S1 is a section between two adjacent towers of the extra-high voltage direct current line.
3. The uninterrupted direct current deicing method for the extra-high voltage direct current line overhead ground wire according to claim 2 is characterized in that the step S2 of shorting the overhead ground wire of the deicing section comprises the following steps:
shorting the overhead ground wire at the first iron tower side in the ice melting section, and grounding the short contact;
in the ice melting section, a down lead is adopted to lead the overhead ground wire at the side of the second iron tower to the bottom of the tower; and the down lead at the side of the second iron tower is connected with the direct-current deicing device when the direct-current deicing is carried out on the line, and is directly grounded when the line works normally.
4. The uninterrupted direct current deicing method for the extra-high voltage direct current line overhead ground wire according to claim 3, wherein the short-circuit point is grounded, in particular through an iron tower body.
5. The uninterruptible direct current deicing method for the extra-high voltage direct current line overhead ground wire according to claim 3, wherein the short circuit transformation is permanent short circuit transformation or temporary short circuit transformation.
6. The uninterrupted direct current deicing method for the extra-high voltage direct current line overhead ground wire according to claim 3, wherein in the step S3, insulation modification is performed on the overhead ground wire of the deicing section, specifically, insulation is performed on the overhead ground wire of the deicing section and an iron tower through an insulator, and meanwhile, insulation is performed on the overhead ground wire of the deicing section and overhead ground wires of other sections of the overhead line through insulators; the insulator is used for insulating the deicing line from the iron tower during direct current deicing, insulating the deicing line from overhead ground wires of other sections during direct current deicing, and preventing lightning strike from penetrating to the ground during normal operation of the overhead ground wires.
7. The uninterruptible direct current deicing method for the extra-high voltage direct current line overhead ground wire according to claim 6, wherein the insulation modification is a permanent insulation modification or a temporary insulation modification.
8. The uninterrupted direct current deicing method for the extra-high voltage direct current line overhead ground wire, which is disclosed in claim 6, is characterized in that the direct current deicing device comprises a power module, a deicing transformer module, a deicing standby power module, a deicing switch module, a deicing rectification module and an induced voltage suppression module; the power supply module, the ice melting transformer module, the ice melting switch module and the ice melting rectification module are sequentially connected in series, the output end of the ice melting standby power supply module is connected with the output end of the ice melting transformer module in parallel, and the port of the induced voltage suppression module is connected with the output end of the ice melting rectification module in parallel; the power supply module is used for providing a power supply for ice melting, and after the output power supply is reduced by the ice melting transformer module, the power supply is input to the ice melting rectifying module by the ice melting switch module, and the ice melting rectifying module converts the received ice melting electric energy into direct current electric energy and outputs the direct current electric energy to the outside for ice melting operation; the ice melting standby power supply module is used for providing auxiliary standby ice melting power supply when the power supply module cannot supply power; the induced voltage suppression module is used for suppressing the induced voltage on the ground wire of the ice melting section in the ice melting process, so that the safety of the ice melting process is ensured.
9. The uninterruptible direct current deicing method for the extra-high voltage direct current line overhead ground wire according to claim 8, wherein the induced voltage suppression module comprises a voltage suppression negative electrode resistor, a voltage suppression negative electrode capacitor, a voltage suppression negative electrode voltage limiter, a voltage suppression positive electrode resistor, a voltage suppression positive electrode capacitor and a voltage suppression positive electrode voltage limiter; the voltage suppression negative electrode resistor, the voltage suppression negative electrode capacitor and the voltage suppression negative electrode voltage limiter are connected in parallel, one end of the parallel connection is grounded, and the other end of the parallel connection is connected with an output negative electrode of the ice melting rectification module; the voltage suppression positive electrode resistor, the voltage suppression positive electrode capacitor and the voltage suppression positive electrode voltage limiter are connected in parallel, one end of the voltage suppression positive electrode resistor, the voltage suppression positive electrode capacitor and the voltage suppression positive electrode voltage limiter are grounded after being connected in parallel, and the other end of the voltage suppression positive electrode resistor, the voltage suppression positive electrode capacitor and the voltage suppression positive electrode voltage limiter are connected with the output positive electrode of the ice melting rectifying module.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211605912.2A CN116131191A (en) | 2022-12-14 | 2022-12-14 | Uninterrupted DC ice melting method for extra-high voltage DC line overhead ground wire |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211605912.2A CN116131191A (en) | 2022-12-14 | 2022-12-14 | Uninterrupted DC ice melting method for extra-high voltage DC line overhead ground wire |
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| CN116131191A true CN116131191A (en) | 2023-05-16 |
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| CN202211605912.2A Pending CN116131191A (en) | 2022-12-14 | 2022-12-14 | Uninterrupted DC ice melting method for extra-high voltage DC line overhead ground wire |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117175523A (en) * | 2023-11-03 | 2023-12-05 | 中国电力工程顾问集团西南电力设计院有限公司 | Method for inhibiting ice melting induced voltage of earth wire of uninterrupted AC line |
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2022
- 2022-12-14 CN CN202211605912.2A patent/CN116131191A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117175523A (en) * | 2023-11-03 | 2023-12-05 | 中国电力工程顾问集团西南电力设计院有限公司 | Method for inhibiting ice melting induced voltage of earth wire of uninterrupted AC line |
| CN117175523B (en) * | 2023-11-03 | 2024-01-26 | 中国电力工程顾问集团西南电力设计院有限公司 | Method for inhibiting ice melting induced voltage of earth wire of uninterrupted AC line |
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