CN110660548A - Lightning arresters and power transmission systems - Google Patents

Abstract

The invention discloses a lightning arrester and a power transmission system, which relate to the technical field of power equipment and are used for improving the heat dissipation efficiency of the lightning arrester, so that the lightning arrester can operate normally with a high charge rate for a long time in a power transmission system with a continuously improved power transmission voltage level or in other power transmission systems. . The arrester includes an insulating casing, and the insulating casing is provided with a plurality of resistance valve sheets, a plurality of metal spacers and at least one fan. The resistance valve sheets and the metal spacers are alternately stacked to form a lightning arrester core column. Each fan and the lightning arrester core The columns are arranged at intervals, and the air outlet of each fan faces the arrester stem. Through the technical scheme of the present invention, the heat dissipation efficiency of the arrester is improved, so that the resistance valve plate of the arrester is less likely to be thermally damaged.

Description

Lightning arresters and power transmission systems

technical field

The invention relates to the technical field of power equipment, and in particular to a lightning arrester and a power transmission system.

Background technique

At present, the main body of the arrester is usually wrapped and sealed by layers of epoxy resin and silicone rubber insulators. Due to the airtight structure of the arrester, the heat in the arrester cannot be dissipated in time, and the heat dissipation efficiency is extremely low. As a result, the components in the arrester are easily aged or damaged due to excessive temperature, and the charging rate of the arrester is limited. Therefore, it is difficult for the existing arrester to adapt to the continuous improvement of the transmission voltage level, and it is difficult to continue to operate normally for a long time with a high charge rate in the transmission system, while reducing the aging loss and failure rate of the arrester.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a lightning arrester and a power transmission system, which are used to improve the heat dissipation efficiency of the lightning arrester, so that the lightning arrester can operate normally for a long time with a high charge rate in a power transmission system whose transmission voltage level is continuously improved, and at the same time reduce the aging loss of the lightning arrester and failure rate.

In order to achieve the above object, the present invention provides the following technical solutions:

A first aspect of the present invention provides a surge arrester, the surge arrester includes an insulating housing, and the insulating housing is provided with a plurality of resistance valve plates, a plurality of metal spacers and at least one fan, the resistance valve plates and the metal spacers are alternately stacked in sequence A lightning arrester core column is constructed, each fan is arranged at intervals from the lightning arrester core column, and the air outlet of each fan faces the lightning arrester core column.

Optionally, the number of fans is two, and the two fans are respectively located on opposite sides of the arrester stem.

Optionally, one of the two fans is located at the upper right corner of the insulating housing, and the other is located at the lower left corner of the insulating housing.

Optionally, the insulating housing is airtight, and the insulating housing is filled with nitrogen gas.

Optionally, the top of the insulating housing is provided with a first air outlet, and the bottom of the insulating housing is provided with a second air outlet.

Optionally, an air guide bar is provided on the side wall of the insulating housing, and the air guide bar is arranged in a three-dimensional spiral shape with the axis of the arrester core column as the center; wherein, the first air outlet and the second air outlet are respectively located opposite to the air guide bar. both ends.

Optionally, the fan includes: an air duct shell, the air duct shell constructs an air duct with an air return port and an air outlet, and the air return port and the air outlet are respectively located on different sides of the air duct shell; a wind wheel arranged in the air duct shell, It is used to make the air flow in the air duct shell flow from the return air outlet to the air outlet.

Optionally, the fan further includes an air guide plate disposed at the air outlet and rotatably connected to the air duct housing.

Optionally, the arrester further includes a first electrode and a second electrode respectively connected to both ends of the arrester stem in the axial direction, and the first electrode and the second electrode respectively extend out of the insulating casing.

Based on the above technical solution of the arrester, a second aspect of the present invention provides a power transmission system, the power transmission system including the arrester in any of the above technical solutions.

Compared with the prior art, the arrester and the power transmission system provided by the present invention have the following beneficial effects:

The lightning arrester provided by the present invention includes the lightning arrester and an insulating casing. The insulating casing is provided with a plurality of resistance valve sheets, a plurality of metal pads and at least one fan, and the resistance valve sheets and the metal pads are alternately superimposed in sequence to form the arrester core column. The arrester stem can be connected between the power grid and the ground wire to protect electrical equipment from high transient overvoltage hazards. In addition, since each fan is spaced from the arrester stem, and the air outlet of each fan faces the arrester stem, at least one fan can make the air flow to the surge arrester stem to realize forced convection heat exchange, which can make the heat on the resistance valve sheet rapidly increase. Dispersion, greatly improve the heat dissipation efficiency of the arrester, thereby effectively reducing the temperature of the resistance valve plate, so that the arrester is not easily damaged due to excessive temperature, so that the arrester can be used in the transmission system where the transmission voltage level is continuously improved. High charge rate for a long time Normal and stable operation, while reducing the aging loss and failure rate of the arrester.

The beneficial effects that can be achieved by the power transmission system provided by the present invention are the same as the beneficial effects that can be achieved by the arrester provided by the above technical solution, and are not repeated here.

Description of drawings

The accompanying drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

1 is a schematic structural diagram of a lightning arrester according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a lightning arrester according to another embodiment of the present invention.

Reference number:

10- Arrester, 102- Insulation shell, 104- Resistor valve plate,

106-Metal spacer, 108-Fan, 110-Air deflector,

112-first electrode, 114-second electrode.

Detailed ways

For ease of understanding, the lightning arrester and the power transmission system provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIGS. 1 and 2 , the arrester 10 provided by the embodiment of the present invention includes an insulating housing 102 . The insulating housing 102 is provided with a plurality of resistance valve plates 104 , a plurality of metal spacers 106 and at least one fan 108 . The valve plate 104 and the metal spacer 106 are alternately stacked to form a surge arrester stem, each fan 108 is spaced from the surge arrester stem, and the air outlet of each fan 108 faces the surge arrester stem.

The arrester 10 provided by the present invention includes that the arrester 10 includes an insulating casing 102, and the insulating casing 102 is provided with a plurality of resistance valve plates 104, a plurality of metal spacers 106 and at least one fan 108, the resistance valve plates 104 and the metal spacers 106 is alternately superimposed to form a surge arrester core column, and the surge arrester core column can be connected between the power grid and the ground wire to protect the electrical equipment from high transient overvoltage hazards. Moreover, since each fan 108 is spaced from the arrester stem, and the air outlet of each fan 108 faces the surge arrester stem, at least one fan 108 can make the air flow to the surge arrester stem to realize forced convection heat exchange, which can make the resistance valve sheet The heat on the 104 is rapidly dissipated, which greatly improves the heat dissipation efficiency of the arrester 10, thereby effectively reducing the temperature of the resistance valve plate 104, so that the arrester 10 is not easily damaged due to excessive temperature, thereby enabling the arrester 10 to transmit power continuously at a higher transmission voltage level. The system operates normally and stably for a long time with a high charge rate.

It is worth mentioning that, with the continuous development of UHV transmission technology, combined with the grid commutated converter valve (LineCommutated Converter, hereinafter referred to as LCC) and voltage source converter valve (Voltage SourceConverter, hereinafter referred to as VSC) power transmission. The system has become an integral part of grid operation. For example, in a common structure of a power transmission system, the inverter side is usually provided with at least one level of LCC and at least one level of VSC in cascade; wherein, the LCC is used to carry the voltage of the high-voltage section, such as 400kV to 800kV; the VSC is used for Carry the voltage of the low voltage section, such as 0kV ~ 400kV. The LCC in the transmission system has a strong dependence on the receiving-end AC system, and is prone to commutation failure when the receiving-end AC system has an AC fault, and the voltage drops to zero, forming a short-circuit path. However, the VSC does not form a current path when an AC fault occurs in the AC system at the receiving end, which makes the LCC transfer the voltage and current of the cascaded VSCs and charge the capacitors in the VSCs. Therefore, as the fault current increases, the voltage on the capacitor in the VSC will increase rapidly. By arranging the arrester in the above-mentioned power transmission system, because the arrester has high heat dissipation efficiency and higher charge rate, the current in the continuous working state can be larger, the residual voltage is lower, and the current leakage effect is better, making the VSC The voltage and current carried on it is not easy to exceed its withstand voltage and current capacity, which improves the protection effect of the VSC.

The above-mentioned metal spacer 106 is used as a transmission medium for voltage and current, and is usually made of conductive materials such as copper or aluminum.

Exemplarily, the insulating case 102 may be an epoxy resin case made of epoxy resin material, or a ceramic case made of ceramic material; when the insulating case 102 is an epoxy resin case, epoxy resin case A silicone rubber shed can be set on the resin shell, and the epoxy resin shell can be integrally formed with the silicone rubber shed; when the insulating shell 102 is a porcelain shell, a porcelain shed can be set on the porcelain shell , the porcelain shell can be integrally formed with the porcelain shed.

In some embodiments, referring to FIGS. 1 and 2 , the number of fans 108 is two, and the two fans 108 are respectively located on opposite sides of the arrester stem.

In this embodiment, by setting the number of fans 108 to two, and the two fans 108 are respectively located on opposite sides of the arrester core column, less fans 108 can be used to make the airflow in the insulating housing 102 effectively and the arrester core. The column performs convection heat exchange, which has the advantages of simple structure, high economy, and good heat exchange effect, so that the heat on the resistance valve plate 104 can be rapidly dissipated, further improving the heat dissipation efficiency of the arrester 10, and reducing the temperature of the resistance valve plate 104. , so that the arrester 10 is not easily damaged due to excessive temperature, thereby improving the withstand voltage capability of the arrester 10, so that the arrester 10 can operate normally and stably for a long time in a power transmission system with an increasing transmission voltage level, and improve the protection effect on the VSC.

In some embodiments, referring to FIGS. 1 and 2 , one of the two fans 108 is located at the upper right corner of the insulating housing 102 and the other is located at the lower left corner of the insulating housing 102 .

In this embodiment, by arranging one of the two fans 108 at the upper right corner of the insulating housing 102 and the other at the lower left corner of the insulating housing 102 , the insulating housing 102 is less prone to dead spots and the airflow is improved. Therefore, the airflow of each part is fully contacted with the arrester stem, which further improves the heat dissipation effect and reduces the heat on the resistance valve sheet 104 of the arrester stem.

In some embodiments, the insulating housing 102 is hermetically sealed, and the insulating housing 102 is filled with nitrogen gas.

In this embodiment, by setting the insulating housing 102 to be airtight, and the insulating housing 102 is filled with nitrogen, on the one hand, the stem of the arrester can be protected, so that the stem of the arrester is not easily disturbed by the external environment, that is, dust, Various impurities such as sewage are not easily attached to the surface of the arrester stem, which improves the safety and reliability of the arrester stem; Convective heat transfer is performed. Due to the relatively small molecular mass of nitrogen and high thermal conductivity, the heat on the arrester stem can be more effectively transferred to the insulating shell 102, and then dissipated to the external environment through the insulating shell 102, thereby effectively reducing the resistance of the arrester stem The temperature on the valve plate 104 makes the resistance valve plate 104 less likely to be damaged due to excessive temperature, so as to improve the voltage withstand capability of the arrester 10, so that the arrester 10 can operate normally and stably for a long time in the power transmission system with the continuously improved transmission voltage level. , to improve the protection of VSC.

In some embodiments, the top of the insulating housing 102 is provided with a first air vent, and the bottom of the insulating housing 102 is provided with a second air vent.

In this embodiment, by arranging the first air outlet at the top of the insulating housing 102 and setting the second air outlet at the bottom of the insulating housing 102, the outside air can be introduced into the insulating housing 102 for convective heat exchange with the arrester core column, And the air after heat exchange can be discharged to the outside of the insulating housing 102, which enhances the heat exchange effect, so as to better protect the resistance valve piece 104 of the arrester core column, so that the resistance valve piece 104 of the arrester core column is not easy to be damaged. If the temperature is too high and it is damaged, the withstand voltage capability of the arrester 10 is improved.

The outside air enters the insulating housing 102 from the first air outlet, and then exits the insulating housing 102 from the second air opening;

As a possible design, a first volute is provided at the first tuyere, and the first volute is provided with a Coanda for leading the airflow in the insulating housing 102 from the first tuyere to the outside of the insulating housing 102 Alternatively, a second volute is provided at the second tuyere, and the second volute is provided with a Coanda surface for leading the airflow in the insulating housing 102 from the second tuyere to the outside of the insulating housing 102 .

In some embodiments, the side wall of the insulating housing 102 is provided with an air guide bar, and the air guide bar is arranged in a three-dimensional helical shape with the axis of the arrester stem as the center; wherein, the first air outlet and the second air outlet are respectively located at the air guide. opposite ends of the strip.

In this embodiment, by arranging an air guide bar on the side wall of the insulating housing 102, the air guide bar is arranged in a three-dimensional helical shape with the axis of the arrester stem as the center, and the first air outlet and the second air outlet are respectively located in the air guide bar. At the opposite ends of the arrester, after the outside air enters the insulating housing 102 , it can flow along the axial direction of the arrester stem in a rotating manner, and then be discharged to the outside of the insulating housing 102 . Through the above solution, the heat on the arrester core can be quickly taken away, the heat dissipation efficiency of the arrester 10 can be further improved, and the temperature of each resistance valve piece 104 of the arrester core can be reduced, so that the arrester 10 is less likely to be damaged due to excessive temperature, and further The voltage withstand capability of the arrester 10 is improved, so that the arrester 10 can operate normally and stably in a power transmission system whose power transmission voltage level is continuously improved, and the protection effect on the VSC is improved.

The outside air enters the insulating housing 102 from the first air outlet, and then forms a cyclone inside the insulating housing 102 through the air guide bars, surrounds the arrester core column around the rotation center of the cyclone, and finally is discharged from the second air outlet to the insulating housing 102 Or, the outside air enters the insulating housing 102 from the second air outlet, and then forms a cyclone inside the insulating housing 102 through the air guide bar, surrounds the arrester stem around the rotation center of the cyclone, and finally is discharged from the first air outlet to the insulating housing. outside of body 102. In this solution, the heat on the arrester stem can be quickly taken away by the outside air, thereby greatly improving the voltage withstand capability of the arrester 10, so that the resistance valve piece 104 on the arrester stem is less prone to high temperature damage, practicability and reliability. are relatively high.

Exemplarily, the air guide bar is inclined toward the first air outlet from the end connected to the insulating housing 102 to the end away from the insulating housing 102 . In this embodiment, the air flow can be effectively guided to flow from the second tuyere to the first tuyere through the air guide strip.

Exemplarily, the cross-sectional shape of the first tuyere is a circle, an ellipse or a rectangle, and the cross-sectional shape of the second tuyere is a circle, an ellipse or a rectangle. Here, it should be noted that the shapes of the first tuyere and the second tuyere are not limited to the above-mentioned regular shapes such as circle, ellipse or rectangle, and the above is only an example, that is, the first tuyere and the second tuyere only need As long as the airflow can pass through, the first tuyere and the second tuyere can also be arranged in irregular shapes.

In some embodiments, the fan 108 includes: an air duct casing, the air duct casing is configured with an air duct having a return air outlet and an air outlet, and the return air outlet and the air outlet are respectively located on different sides of the air duct casing; The wind wheel is used to make the air flow in the air duct shell flow from the air return port to the air outlet.

In this embodiment, the fan 108 includes an air duct housing and a wind wheel arranged in the air duct housing. By arranging the air return port and the air outlet on different sides of the air duct housing, the wind wheel is used to make the air flow in the air duct housing. Flowing from the air return port to the air outlet prevents dead corners from appearing in the insulating housing 102 , and more airflow in the insulating housing 102 can conduct convective heat exchange with the arrester core column, thereby improving the heat dissipation efficiency.

Exemplarily, the air return port and the air outlet are located on opposite sides of the air duct housing, which further improves the flow effect of airflow (eg, nitrogen, outside air, and the original air in the insulating housing 102 ).

Exemplarily, the impeller is a cross-flow impeller or an axial impeller.

In some embodiments, referring to FIG. 2 , the fan 108 further includes an air deflector 110 disposed at the air outlet and rotatably connected with the air duct shell.

In this embodiment, by arranging the air guide plate 110 rotatably connected to the air duct shell at the air outlet of the fan 108, the flow direction of the air flow discharged from the air outlet of the fan 108 can be adjusted, and the flexibility is high, so that more It is good to cool down the arrester stem.

Exemplarily, the air deflector 110 is rotatably connected to one side of the air outlet through a pivot, and the pivot can be set horizontally or at an angle to the horizontal plane, such as 30 degrees, 45 degrees, 60 degrees or 90 degrees. degree, etc.

In order to facilitate the control, the above-mentioned pivot shaft can also be connected with a motor, and the rotation control of the wind deflector 110 can be realized by the rotation of the motor.

In some embodiments, referring to FIG. 2 , the arrester 10 further includes a first electrode 112 and a second electrode 114 respectively connected to both ends of the arrester stem in the axial direction, the first electrode 112 and the second electrode 114 respectively extending to the insulation outside the housing 102 .

In this embodiment, by arranging the first electrode 112 and the second electrode 114, it is convenient to connect the arrester 10 with external equipment, for example, it is convenient to connect the arrester 10 between the power grid and the ground wire, that is, to connect multiple arresters 10 to the ground. The resistance valve plate 104 is connected in series between the power grid and the ground wire to protect the electrical equipment from high transient overvoltage hazards.

On the other hand, an embodiment of the present invention provides a power transmission system (not shown), the power transmission system includes the arrester 10 as in any one of the above technical solutions.

In the power transmission system provided by the present invention, since the arrester 10 has high heat dissipation efficiency, the temperature of each resistance valve plate 104 can be effectively lowered, and the heat on each resistance valve plate 104 can be rapidly dissipated, so the withstand voltage of the arrester 10 can be improved. Therefore, each resistor is not easily damaged due to excessively high temperature, so that the VSC can be effectively protected by the arrester 10 when the power transmission voltage level is continuously improved.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (10)

1. The utility model provides an arrester, its characterized in that, the arrester includes insulating housing, be equipped with a plurality of resistance valve blocks, a plurality of metal cushion and at least one fan in the insulating housing, the resistance valve block with metal cushion superposes in turn in proper order and constructs the arrester stem, every the fan with arrester stem interval sets up, and every the air outlet orientation of fan the arrester stem.

2. A surge arrester as claimed in claim 1 wherein the number of said wind turbines is two, the two wind turbines being located on opposite sides of the surge arrester stem.

3. A lightning arrester according to claim 2, characterized in that one of the two fans is located in the upper right corner of the insulating housing and the other is located in the lower left corner of the insulating housing.

4. A lightning arrester according to any of claims 1-3 characterized in that the insulating casing is closed and nitrogen is filled in the insulating casing.

5. A lightning arrester according to any one of claims 1-3, characterized in that the top of the insulating casing is provided with a first tuyere and the bottom of the insulating casing is provided with a second tuyere.

6. The arrester according to claim 5, wherein a wind guide strip is provided on a side wall of the insulating housing, and the wind guide strip is spirally provided in a three-dimensional manner with an axis of the arrester core column as a center;

the first air opening and the second air opening are respectively located at two opposite ends of the air guide strip.

7. A lightning arrester according to any one of claims 1-3, characterized in that the wind turbine comprises:

the air duct shell constructs an air duct with an air return inlet and the air outlet, and the air return inlet and the air outlet are respectively positioned on different sides of the air duct shell;

and the wind wheel is arranged in the air duct shell and used for enabling the air flow in the air duct shell to flow to the air outlet from the air return inlet.

8. The arrester of claim 7 wherein the fan further comprises a deflector disposed at the air outlet and rotatably coupled to the duct shell.

9. The surge arrester of any one of claims 1 to 3, further comprising a first electrode and a second electrode respectively connected to both ends of the surge arrester stem in an axial direction, the first electrode and the second electrode respectively extending outside the insulating housing.

10. An electric power transmission system, characterized in that the electric power transmission system comprises an arrester as claimed in any of claims 1-9.

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