CN105207161A - Double earth wire ice melting system - Google Patents

Abstract

The embodiment of the present invention discloses a double-ground wire ice-melting system, which includes: the head tower of the target ice-covered section, the end tower, the middle tower, and the double ground wires erected on the towers, and the double ground wires located at the end towers. short circuit; ice-melting power supply that outputs three-phase alternating current; a rectifier that rectifies the three-phase alternating current output by the ice-melting power supply into direct current. The target ice-covered section is the insulation transformation section. Select the target ice-covered section for insulation transformation, avoiding the insulation transformation of the entire ground line, and reducing the cost of ice-melting transformation; the access point of the ice-melting power supply is not fixed, and it is connected according to the selected target ice-covered section , which avoids ice-melting power supply from the initial substation from the power supply, increases the flexibility of ice-melting power supply access, and does not require line power failure during the actual ground-line ice-melting process, which enhances the reliability of line power supply.

Description

A dual-ground ice-melting system

technical field

The invention relates to the field of ice melting for power grids, in particular to a double ground wire ice melting system.

Background technique

In the current power grid, when the temperature is low, the transmission lines are prone to ice coating, which may lead to overloading of transmission lines, ice flashover of insulator strings, conductor galloping, and uneven ice coating or out-of-schedule accidents, resulting in huge losses. Economic loss and serious social impact.

As the ice melting technology of overhead transmission lines matures day by day, icing on ground wires has become a bottleneck in the recovery of tripping lines after ice disasters. The hazards caused by the icing of overhead ground wires to transmission lines are mainly divided into two categories: first, the strands and wires of overhead ground wires are broken under the action of ice load. The broken ground wire may be suspended in the air or directly on the transmission line, which may easily cause the transmission line to discharge to the ground wire or directly short-circuit the fault, making the transmission line unable to transmit power normally. The breakage of the overhead ground wire will also cause the mechanical system of the transmission line to be unbalanced. The tower tilts or even collapses, burying hidden dangers. Second, the sag of the overhead ground wire is too low under the gravity of the ice load. Excessive sag, coupled with the special aerodynamic characteristics of ice-coated conductors, can easily lead to galloping of the ground conductors, thus increasing the risk of discharge between the conductors and ground conductors. However, the normal sag is restored, and the distance between the ground wire and the wire may be less than the safe distance because it cannot be deiced, which will cause discharge between the ground wires or even direct discharge.

The main factor that ground wire melting is different from wire melting is that the ground wire is directly connected to the tower and grounded, which is not convenient for applying voltage to the ground wire melting circuit. At present, the method of deicing the ground wire is to insulate the whole line of the ground wire, that is, to carry out the whole line insulation transformation of the overhead ground wire that needs to be melted. The wire heats up and the ice falls off.

However, due to the different terrains and climatic environments of transmission lines, the icing section of transmission lines in many places accounts for a small proportion of the total line length, and it is not necessary to insulate the entire line. Therefore, at this time, the entire line Insulation transformation will cause a lot of waste of resources. Therefore, how to melt the ground wire only for the ice-covered section and save the transformation cost is a technical problem to be solved by those skilled in the art.

Contents of the invention

The purpose of the present invention is to provide a dual-ground wire ice-melting system, which can only melt ice on the ground wire for the ice-covered section, and save the cost of ice-melting.

In order to solve the problems of the technologies described above, the present invention provides the following technical solutions:

A dual-ground deicing system comprising:

The first end tower, the end tower, the middle section tower and the double ground wires erected on the towers of the target ice-covered section, the double ground wires at the end towers are short-circuited;

An ice-melting power supply that outputs three-phase alternating current;

A rectifier for rectifying the three-phase alternating current output by the ice-melting power supply into direct current, the positive pole and negative pole of the output end of the rectifier are respectively connected to the double ground wires located at the head tower;

Wherein, the target ice-covered section where the pole tower in the middle section is located is an insulation transformation section.

Preferably, it also includes: a cable for leading down the double ground wire located at the head-end tower to the tower foot of the head-end tower; connecting the cable and the rectifier, and reliably grounding the down-leading connection device.

Preferably, the insulators erected on the tower in the middle section are gap insulators.

Preferably, the insulators at the head tower and the end tower are gap insulators.

Preferably, the downward connecting device includes a first downward connecting sub-device and a second downward connecting sub-device with the same structure, and each downward connecting sub-device includes:

Insulation partition;

The first single-pole high-voltage isolating switch and the second single-pole high-voltage isolating switch fixedly arranged on the insulating partition, wherein, the first end of the first single-pole high-voltage isolating switch and the first end of the second single-pole high-voltage isolating switch The first ends are connected, the second end of the first unipolar high-voltage isolating switch is connected to the output end of the rectifier, the first end of the second unipolar high-voltage isolating switch is connected to the cable, and the second unipolar high-voltage isolating switch is connected to the cable. The second end of the high voltage isolating switch is grounded.

Preferably, the ice-melting power supply is a generator car or a power distribution line.

Preferably, the rectifier is a thyristor ground wire ice-melting device that rectifies the three-phase alternating current output by the ice-melting power supply into an adjustable direct current.

Compared with the prior art, the above-mentioned technical solution has the following advantages:

In the double-ground deicing system provided by the embodiment of the present invention, since the double-ground wires at the terminal tower are short-circuited, and the positive and negative poles at the output end of the rectifier are respectively connected to the double-ground wires at the head-end tower, thus forming an ice-melting circuit. The target ice-covered section is selected for insulation transformation, which avoids the insulation transformation of the entire ground line, reduces the workload of tower transformation, and reduces the cost of ice-melting transformation; the number of transformation points is reduced, and the efficiency of the ice-melting circuit is improved. Overall reliability; the access point of the ice-melting power supply is not fixed, and it is connected according to the selected target ice-covered section, which avoids ice-melting power supply from the power supply from the initial substation, increases the flexibility of ice-melting power supply access, and In the process of actually melting the ice of the ground wire, there is no need for line power failure, which enhances the reliability of the line power supply.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are For some embodiments of the present invention, those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic structural diagram of a dual-ground deicing system provided by a specific embodiment of the present invention;

Fig. 2 is a schematic diagram of wiring of the down-leading connection device provided by a specific embodiment of the present invention;

Fig. 3 is a schematic diagram of the lead-down of the ground wire on the tower at the head end provided by a specific embodiment of the present invention.

Detailed ways

The core of the present invention is to provide a dual ground wire ice-melting system, which can reduce the cost of ice-melting reconstruction and enhance the reliability of line power supply.

In order to make the above objects, features and advantages of the present invention more comprehensible, the specific implementation manners of the present invention will be described in detail below in conjunction with the accompanying drawings.

In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways than those described here, and those skilled in the art can make similar extensions without departing from the connotation of the present invention. Accordingly, the present invention is not limited to the specific embodiments disclosed below.

Please refer to FIG. 1 , which is a schematic structural diagram of a dual-ground deicing system provided by a specific embodiment of the present invention.

In a specific embodiment of the present invention, a dual-ground wire ice-melting system includes: the head end tower 1, the end tower 2, the middle tower 3, and the double ground wire erected on the tower in the target ice-covered section 4. The double ground wires 4 located at the terminal tower 2 are short-circuited; the ice-melting power supply 5 that outputs three-phase alternating current; the rectifier 6 that rectifies the three-phase alternating current output by the ice-melting power supply 5 into direct current, and the rectifier 6 The positive pole and the negative pole of the output end are respectively connected to the double ground wire 4 located at the first pole tower 1; wherein, the target ice-covered section where the middle section pole tower 3 is located is an insulation reconstruction section.

In this embodiment, a three-phase alternating current is used as the ice-melting power supply 5 , wherein the ice-melting power supply 5 can be a generator car or a power distribution line. The rectifier 6 rectifies the three-phase alternating current output by the ice-melting power supply 5 into direct current. The rectifier 6 is preferably a thyristor ground ice-melting device with adjustable direct current output, that is, the three-phase alternating current is rectified through the thyristor ground ice-melting device, and the output current is adjustable. The positive and negative poles of the output terminal of the rectifier are respectively connected to the ground wire of the tower at the head end of the target ice-covered section, and the ground wire of the tower tower at the end of the target ice-covered section is short-circuited to form a loop. The ice-covered section is insulated.

In the specific implementation plan, it mainly includes three transformation processes:

The first is to modify the head-end tower: the head-end tower 1 uses gap insulators to modify the side of the ice-melting circuit; the cable 7 is used to lead the double ground wire 4 at the head-end tower to the tower foot of the head-end tower, so that For the access of the ice-melting power supply 5; connect the down-lead connection device 8 at the interface of the cable 7 to connect the rectifier 6. Since the ground wire of the target ice-covered section cannot be reliably grounded after the insulation transformation of the target ice-covered section, the lightning protection performance is poor. During the period, the ground wire has the function of lightning protection, and during the ice-melting period, the rectifier on the side of the ice-melting power supply is connected to the down-leading connection device 8, and can be connected to the above-mentioned cable 7 to form an ice-melting circuit.

The second is to transform the tower in the middle section: erect gap insulators on the tower in the middle section to insulate and transform the target ice-covered section where the tower in the middle section is located.

The third is to modify the terminal tower: the terminal tower also adopts gap insulators to modify the side of the ice-melting circuit, removes the connecting lead wire of the original tension section, and uses the lead wire to overlap between the two ground wires (that is, double ground wires), so that The positive and negative poles of the ice melting system are connected here to form a complete ice melting circuit.

Since the double ground wires at the end tower are short-circuited, and the positive and negative poles at the output end of the rectifier are respectively connected to the double ground wires at the head tower, an ice-melting loop is formed. The target ice-covered section is selected for insulation transformation, which avoids the insulation transformation of the entire ground line, reduces the workload of tower transformation, and reduces the cost of ice-melting transformation; the number of transformation points is reduced, and the efficiency of the ice-melting circuit is improved. Overall reliability; the access point of the ice-melting power supply is not fixed, and it is connected according to the selected target ice-covered section, which avoids ice-melting power supply from the power supply from the initial substation, increases the flexibility of ice-melting power supply access, and In the process of actually melting the ice of the ground wire, there is no need for line power failure, which enhances the reliability of the line power supply.

Please refer to Figure 2 and Figure 3, Figure 2 is a schematic diagram of the wiring of the down-leading connection device provided by a specific embodiment of the present invention; Figure 3 is a schematic diagram of the down-leading of the ground wire on the head tower provided by a specific embodiment of the present invention .

In one embodiment of the present invention, the above-mentioned down-leading connection device preferably includes a first down-leading connection sub-device and a second down-leading connection sub-device with the same structure, and each down-leading connection sub-device includes: an insulating partition 21; The first single-pole high-voltage isolating switch 22 and the second single-pole high-voltage isolating switch 23 on the insulating partition 21, wherein the first end of the first single-pole high-voltage isolating switch 22 is isolated from the second single-pole high-voltage The first ends of the switch 23 are connected, the second end of the first unipolar high-voltage isolating switch 22 is connected to the output end of the rectifier, and the first end of the second unipolar high-voltage isolating switch 23 is connected to the cable, so The second end of the second unipolar high voltage isolating switch 23 is grounded.

In this embodiment, as shown in Figure 3, when using a cable to lead the ground wire down, the cable 7 is usually led down along the edge of the head end tower 1, and the cable is fixed on the head end tower using a cable lead-down clamp , to prevent the cable from being affected by factors such as wind and drifting to affect the down-leading of the ground wire. In the power grid, the preferred cable is a 10kV single-core cable, and the copper-aluminum terminal is preferred between the ground wire and the cable, and the copper-aluminum terminal is fixed on the head-end pole tower through a copper-aluminum terminal clamp.

Due to the large distance between the two tower feet of the tower, in order to facilitate the connection between the ground wire and the positive and negative poles of the rectifier, a down-leading connection sub-device is respectively set at the two tower feet where the two wires lead down, as shown in Figure 2 As shown, the down-lead connection sub-device includes an insulating partition to prevent all parts on the down-lead connection sub-device from being grounded; the power supply wiring 24 on the ice-melting power supply side is fixed on the insulating column 25 on the insulation partition, and then the electrical Connected to the second end of the first single-pole high-voltage isolating switch, the first end of the first single-pole high-voltage isolating switch is connected to the first end of the second single-pole high-voltage isolating switch, and the first end of the second single-pole high-voltage isolating switch The cable 7 leading to the ground wire is led out from the end; the second end of the second single-pole high-voltage isolating switch is grounded and connected to the grounding grid of the tower.

It should be noted that in this embodiment, it is only preferred that the downward connection device includes the first downward connection sub-device and the second downward connection sub-device with the same structure, and the first downward connection sub-device and the second downward connection sub-device can also be The combination of the leading and connecting sub-devices depends on the circumstances, which is not limited in this embodiment.

In summary, the dual-ground wire ice-melting system provided by the embodiment of the present invention selects the target ice-covered section for insulation transformation, avoids the insulation transformation of the entire ground wire, reduces the workload of tower transformation, and reduces The cost of ice-melting transformation is reduced; the number of transformation points is reduced, which improves the overall reliability of the ice-melting circuit; The initial substation is used for ice-melting power supply, which increases the flexibility of ice-melting power supply access, and does not require line power failure during the actual ground line ice-melting process, which enhances the reliability of line power supply.

In addition, the transformation of the high altitude and serious ice-covered areas greatly reduces the workload of tower reconstruction. In low-altitude areas, only the target ice-covered area is reconstructed, and the length of the heating ground wire is reduced, avoiding the temperature rise of the ground wire. The possibility of line, the safety factor is greatly improved.

The dual-ground ice-melting system provided by the present invention can use a generator car or a distribution transformer as the ice-melting power supply, and can select the ice-melting current according to the actual situation or predict ice disasters, and use the same current to prevent the ground wire from icing. .

The above is a detailed introduction of the double ground wire deicing system provided by the present invention. In this paper, specific examples are used to illustrate the principles and implementation methods of the present invention, and the descriptions of the above embodiments are only used to help understand the present invention and its core ideas. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (7)

1. a double earth wire ice melting system, is characterized in that, comprising:

The head end shaft tower of target icing section, end shaft tower, interlude shaft tower and the double earth wire be erected on shaft tower, be positioned at the double earth wire short circuit at described end shaft tower place;

Export the ice-melt power supply of three-phase alternating current;

The three-phase alternating current that described ice-melt power supply exports is rectified into galvanic rectifier, and positive pole and the negative pole of described rectifier output end are connected the double earth wire being positioned at described head end shaft tower place respectively;

Wherein, described interlude shaft tower place target icing section is insulating transformation section.

2. double earth wire ice melting system according to claim 1, is characterized in that, also comprise:

For make to be positioned at described head end shaft tower place double earth wire under cause the cable of the column foot of described head end shaft tower;

Connect described cable and described rectifier, and draw jockey under reliable ground.

3. double earth wire ice melting system according to claim 2, is characterized in that, the tower-mounted insulator of described interlude bar is gap insulator.

4. double earth wire ice melting system according to claim 3, is characterized in that, the insulator at described head end shaft tower and described end shaft tower place is gap insulator.

5. the double earth wire ice melting system according to any one of claim 2 to 4, is characterized in that, draws jockey and comprises identical the drawing connexon device for first time and draw connexon device second time of structure, draw connexon device and comprise under each under described:

Insulating barrier;

Be fixedly installed on the first single-electrode high-voltage isolating switch on described insulating barrier and the second single-electrode high-voltage isolating switch, wherein, the first end of described first single-electrode high-voltage isolating switch is connected with the first end of the second single-electrode high-voltage isolating switch, second end of described first single-electrode high-voltage isolating switch connects the output of described rectifier, the first end of described second single-electrode high-voltage isolating switch connects described cable, the second end ground connection of described second single-electrode high-voltage isolating switch.

6. double earth wire ice melting system according to claim 5, is characterized in that, described ice-melt power supply is generator car or distribution line.

7. double earth wire ice melting system according to claim 6, is characterized in that, described rectifier is the thyristor ground wire deicing device three-phase alternating current that described ice-melt power supply exports being rectified into adjustable DC electricity.