CN105321027A - Lightning protection method and apparatus for power transmission line - Google Patents

Abstract

The invention discloses a lightning protection method and device for transmission lines. Among them, the lightning protection method of the transmission line includes: obtaining the lightning parameter of the transmission line; calculating the lightning protection degree of the transmission line tower by base according to the lightning parameter; and setting the lightning protection mode of the transmission line according to the lightning protection degree. The invention solves the problem of low lightning protection performance of the transmission line in the prior art, and further achieves the effect of improving the safety and stability of the transmission line.

Description

Lightning protection method and device for transmission line

technical field

The invention relates to the field of electric power technology, in particular to a lightning protection method and device for power transmission lines.

Background technique

In the prior art, the lightning risk assessment of transmission lines mainly relies on the calculation of the lightning resistance level and lightning trip rate of the transmission line, and generally only calculates the lightning trip rate of several typical towers in the line under typical topography and traditional lightning parameters. When evaluating the lightning flashover characteristics of the entire line, the calculated lightning trip rate of typical towers is generally only weighted and averaged according to the ratio of various topography and landforms in the line corridor. The relative risk of tower lightning flashover makes it impossible to accurately protect the transmission circuit against lightning, resulting in low lightning protection performance of the transmission line.

Aiming at the problem of low lightning protection performance of transmission lines in the related art, no effective solution has been proposed yet.

Contents of the invention

The main purpose of the present invention is to provide a lightning protection method and device for transmission lines to solve the problem of low lightning protection performance of transmission lines in the prior art.

According to one aspect of the present invention, a lightning protection method for a power transmission line is provided.

The lightning protection method for a power transmission line according to the present invention includes: obtaining the lightning parameters of the power transmission line; calculating the lightning protection degree of the power transmission line base-to-tower according to the lightning parameters; and setting the lightning protection degree according to the lightning protection degree Lightning protection methods for transmission lines.

Further, obtaining the lightning parameters of the transmission line includes: obtaining the shielding trip rate and the counter-attack trip rate of the transmission line, and calculating the lightning protection degree of the transmission line based on the base tower according to the lightning parameters includes: The shielding trip rate and the counter-attack trip rate are calculated based on the lightning protection degree of the transmission line base tower.

Further, calculating the lightning protection degree of the power transmission line tower by base according to the shielding tripping rate and the counterattack tripping rate includes: searching for the value of the shielding tripping rate from a plurality of first preset index ranges. The first range is obtained; the degree level corresponding to the first range is obtained to obtain the first level; the index range of the counter-attack tripping rate is found from a plurality of second preset index ranges, and the second range is obtained. Two ranges; obtain the degree level corresponding to the second range to obtain the second level; find the index range where the sum of the shielding trip rate and the counterattack trip rate is located in a plurality of third preset index ranges, obtaining the third range; obtaining the degree grade corresponding to the third range to obtain the third grade; and combining the first grade, the second grade and the third grade to obtain the lightning protection degree of the transmission line .

Further, the multiple first preset index ranges include [0,0.5S _r ), [0.5S _r ,S _r ), [S _r ,1.5S _r ) and [1.5S _r ,∞), wherein, S _r is the first preset parameter, and the multiple second preset index ranges include [0,0.5S _f ), [0.5S _f ,S _f ), [S _f ,1.5S _f ) and [1.5S _f ,∞), wherein, S _f is the second preset parameter, and the multiple third preset index ranges include [0,0.5(S _r +S _f )), [0.5(S _r +S _f ),( S _r +S _f )), [(S _r +S _f ),1.5(S _r +S _f )) and [1.5(S _r +S _f ),∞).

According to another aspect of the present invention, a lightning protection device for a power transmission line is provided.

The lightning protection device for a power transmission line according to the present invention includes: an acquisition unit for acquiring lightning parameters of the power transmission line; a calculation unit for calculating the lightning protection degree of the power transmission line base-to-tower according to the lightning parameters and a setting unit, configured to set the lightning protection mode of the transmission line according to the lightning protection degree.

Further, the acquisition unit includes: an acquisition subunit, configured to acquire the shielding trip rate and counter-attack trip rate of the transmission line, and the calculation unit includes: a calculation subunit, configured to obtain the shielding trip rate and counterattack trip rate according to the shielding trip rate and The counter-attack tripping rate is calculated based on the lightning protection degree of the transmission line base-to-tower.

Further, the calculation subunit includes: a first search module, configured to search the index range of the shielding trip rate from multiple first preset index ranges to obtain the first range; a first acquisition module, It is used to obtain the degree level corresponding to the first range to obtain the first level; the second search module is used to search for the index range of the counter-attack trip rate from a plurality of second preset index ranges to obtain the second range; the second acquisition module is used to obtain the degree level corresponding to the second range to obtain the second level; the third search module is used to find the shielding tripping rate and the shielding trip rate from multiple third preset index ranges The index range where the sum of the counterattack tripping rates is located is to obtain the third range; the third acquisition module is used to obtain the degree level corresponding to the third range to obtain the third level; and the synthesis module is used to synthesize the The first level, the second level and the third level obtain the lightning protection degree of the transmission line.

Further, the multiple first preset index ranges include [0,0.5S _r ), [0.5S _r ,S _r ), [S _r ,1.5S _r ) and [1.5S _r ,∞), wherein, S _r is the first preset parameter, and the multiple second preset index ranges include [0,0.5S _f ), [0.5S _f ,S _f ), [S _f ,1.5S _f ) and [1.5S _f ,∞), wherein, S _f is the second preset parameter, and the multiple third preset index ranges include [0,0.5(S _r +S _f )), [0.5(S _r +S _f ),( S _r +S _f )), [(S _r +S _f ),1.5(S _r +S _f )) and [1.5(S _r +S _f ),∞).

In the present invention, obtain the lightning parameters of the transmission line; calculate the lightning protection degree of the transmission line based on the base tower according to the lightning parameters; and set the lightning protection of the transmission line according to the lightning protection degree Way. By acquiring the radar parameters and calculating the lightning protection degree based on this, and then setting the lightning protection mode of the transmission line according to the lightning protection degree, it is possible to comprehensively consider various factors and characteristics such as lightning activities, line structure, and topography of the transmission line. Using the lightning parameters obtained based on the statistical analysis of the monitoring data of the lightning monitoring system, the lightning protection calculation is carried out for the base tower of the transmission line, which reflects the relative lightning protection performance of each base tower of a transmission line, which can effectively help the design and construction of the transmission line. The operation department takes more detailed and targeted lightning protection measures to improve the lightning protection performance of the line, manages the power grid more finely, solves the problem of low lightning protection performance of the transmission line in the prior art, and then achieves the improvement of the transmission line. safety and stability effects.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

Fig. 1 is the flowchart of the lightning protection method of transmission line according to the embodiment of the present invention; And

Fig. 2 is a schematic diagram of a lightning protection device for a power transmission line according to an embodiment of the present invention.

detailed description

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is an embodiment of a part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "first" and "second" in the description and claims of the present invention and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

In the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

Example 1

According to the embodiments of the present invention, a method embodiment that can be implemented or executed by the device embodiment of the present application can be provided. It should be noted that the steps shown in the flow charts of the drawings can be implemented in such as a set of computer-executable instructions and, although a logical order is shown in the flowcharts, in some cases the steps shown or described may be performed in an order different from that shown or described herein.

According to an embodiment of the present invention, a lightning protection method for a power transmission line is provided. The lightning protection method for a power transmission line provided by the embodiment of the present invention is described in detail below:

Fig. 1 is a flowchart of a lightning protection method for a power transmission line according to an embodiment of the present invention. As shown in Fig. 1, the method includes the following steps S102 to S106:

S102: Obtain the lightning parameters of the transmission line, wherein the lightning parameters are based on the lightning data accumulated by the operation of the lightning monitoring system, divide the line corridor in the form of a grid, count, analyze and obtain the data that can reflect the different time and different areas of the line corridor Lightning parameters such as lightning density, cumulative probability distribution of lightning current amplitude and other characteristics of lightning activity.

S104: Calculate the lightning protection degree of the base towers of the transmission line according to the lightning parameters, that is, according to the set evaluation standard, combined with the calculation results of the lightning trip rate of the base towers, evaluate the lightning resistance performance of each base tower, and combined with the tower. Analyze the reasons why towers with weak lightning resistance performance are prone to flashover based on the lightning activity parameters in the area, tower structure, insulation configuration, and topographic features.

S106: Set the lightning protection mode of the transmission line according to the lightning protection degree. Specifically, based on the evaluation results of lightning protection performance, combined with the analysis of the reasons for tower flashover and the characteristics of various lightning protection measures, targeted lightning protection measures and treatment plans were formulated, and after the implementation of the lightning protection transformation plan Calculate the lightning trip rate again to evaluate the effect of lightning protection transformation.

The lightning protection method of the transmission line provided by the embodiment of the present invention obtains the radar parameters, calculates the lightning protection degree based on this, and then sets the lightning protection mode of the transmission line according to the lightning protection degree, and realizes comprehensively considering the lightning of the transmission line Various factors and characteristics such as activity, line structure, terrain and landform, etc., using the lightning parameters obtained from the statistical analysis of the monitoring data of the lightning monitoring system, lightning protection calculations are carried out for the base towers of the transmission line, reflecting the relative strength of each base tower of a transmission line The strength of the lightning protection performance can effectively help the design and operation departments of transmission lines to take more detailed and targeted lightning protection measures to improve the lightning protection performance of the line, manage the power grid more finely, and solve the problems of transmission lines in the prior art. The problem of low lightning protection performance, and then achieve the effect of improving the safety and stability of transmission lines.

Among them, obtaining the lightning parameters of the transmission line includes: obtaining the shielding tripping rate P _r and the counterattack tripping rate P _f of the transmission line, and correspondingly, calculating the lightning protection degree of the transmission line tower by base according to the lightning parameters includes: according to the shielding The trip rate P _r and the counter trip rate P _f are used to calculate the lightning protection degree of the transmission line base tower.

Specifically, according to the shielding tripping rate _Pr and the counterattack tripping rate _Pf , the calculation of the lightning protection degree of the transmission line base tower includes: finding the shielding tripping rate _Pr from within a plurality of first preset index ranges The index range is obtained to obtain the first range; the degree level corresponding to the first range is obtained to obtain the first level; the index range of the counter-attack tripping rate P _f is found from multiple second preset index ranges to obtain the second range; The degree level corresponding to the second range is obtained to obtain the second level; the index range where the tripping rate P is located is searched from multiple third preset index ranges to obtain the third range, wherein the tripping rate P is the shielding tripping rate P _r and the sum of the counter-attack tripping rate P _f ; obtain the level corresponding to the third range to obtain the third level; and integrate the first level, the second level and the third level to obtain the lightning protection degree of the transmission line.

In the embodiment of the present invention, as shown in Table 1, multiple first preset index ranges can be set as [0,0.5S _r ), [0.5S _r ,S _r ), [S _r ,1.5S _r ) and [1.5S _r ,∞), multiple second preset index ranges can be set to [0,0.5S _f ), [0.5S _f ,S _f ), [S _f ,1.5S _f ) and [1.5S _f , ∞), multiple third preset index ranges can be set to [0,0.5(S _r +S _f )), [0.5(S _r +S _f ),(S _r +S _f )), [(S _r +S _f ),1.5(S _r +S _f )) and [1.5(S _r +S _f ),∞), wherein, S _r is the first preset parameter, and S _f is the second preset parameter.

Table 1

Among them, the first preset parameter Sr and the second preset parameter Sf are respectively the shielding risk control index and the counterattack risk control index; The specified value of the tripping rate in Article 89 of the Management Specifications for Transmission Lines (hereinafter referred to as the "Code") (40 thunderstorm days in the specification) × the proportion of shielding in the operating experience; the second preset parameter Sf can be The specified value of trip rate × the proportion of counterattack in operation experience. The lightning strike tripping rate of lines of each voltage level in the "Specification" (the standard is that the average annual ground-to-ground flash density is 2.78 times/(km2·a)), should reach the following indicators:

110kV: 0.525 times/100km·year; (this line is based on 110kV line).

Considering that shielding strikes account for 4.4% and counterattacks account for 95.6% of lightning faults, the shielding trip rate index value is set at 0.023 times/100 km·year, and the counterattack trip rate index value is set at 0.502 times/100 km·year, then the above Table 1 can be further expressed as the following table 2:

Table 2

The first default indicator range [0,0.012) [0.012,0.023) [0.023,0.035) [0.0.35,∞) grade A B C D. The second default indicator range [0,0.251) [0.251,0.502) [0.502,0.753) [0.753,∞) grade A B C D. The third preset indicator range [0,0.263) [0.263,0.525) [0.525,0.788) [0.788,∞) grade A B C D.

Through the above method, the lightning protection degree (that is, the lightning flashover risk) of each base tower of the transmission line is divided into A, B, C, and D, and the relative strength of each tower's shielding and counter-attack lightning protection performance is further improved. express it intuitively. Subsequently, the lightning protection mode of the transmission line can be set according to the level of lightning protection performance, and lightning protection measures can be strengthened for towers with relatively weak wind and lightning performance. Specifically, in the embodiment of the present invention, the following lightning protection measures can be adopted:

1. Reduce the protection angle

With the gradual reduction of the protection angle of the line, the shielding rate of the line shows a downward trend, and reducing the protection angle is a more effective method to reduce the shielding trip rate. However, for existing lines, it is not feasible to change the protection angle of the line, and for towers with a large ground inclination in mountainous areas, the protection angle cannot be greatly reduced due to the limitation of the tower head design, so other effective shielding protection measures should be taken.

2. Strengthen the line insulation level

Improving the insulation level of the line is also a method to enhance the lightning resistance level of the line. By improving the insulation level of the line, the U50% discharge voltage of the insulator can be increased, and the lightning resistance level of the line can be improved.

3. Reduce the tower grounding resistance

Reducing the grounding resistance of towers is a basic anti-counterattack measure for high-voltage transmission lines. Reducing the grounding resistance of towers can reduce the potential of lightning strikes on the top of towers, improve the lightning resistance level of lines, and effectively prevent counterattack accidents. There are many measures to reduce the grounding resistance of towers, such as horizontal extension grounding body, deep-buried grounding electrode, filling with low-resistance materials, and installing conductive grounding modules.

4. Set up the coupling ground wire

There are two main functions of the coupling ground wire: one is to increase the coupling coefficient between the lightning conductor and the conductor, thereby reducing the counterattack of the voltage at both ends of the insulator string and the component of the induced voltage; The shunting function of the tower reduces the voltage that the insulators bear and improves the lightning resistance level of the line. However, it is difficult to erect coupling ground wires. Limited by terrain conditions, the power consumption of line operation will be increased, and trees may need to be felled, which will increase the workload and difficulty of line operation and maintenance, and its economic cost is also high.

5. Set up the bypass ground wire

The erection of the bypass ground wire can enhance the shielding effect on the wires, and has a certain effect of reducing lightning shielding, but it needs to erect additional towers and wires, and the economic cost is very high.

6. Install protection gap

The main function of the protective gap is to protect the insulator from damage through arc flashover when lightning strikes occur, which can reduce the lightning strike accident rate of the line. For existing lines, the installation of parallel gaps will short-circuit some insulators, resulting in a decrease in the insulation level of the line, which in turn leads to an increase in the lightning trip rate.

7. Install wave-blocking lightning-termination device

In domestic and foreign operating experience, the lightning strike distance from the central lightning protection line and its vicinity cause a very small chance of flashover and tripping. Therefore, as long as the tower head of the transmission line and its vicinity are not subjected to lightning strikes, the lightning strike tripping rate of the transmission line will be greatly reduced. . It can be seen that the lightning protection of transmission lines can be attributed to the lightning protection centered on the tower to a large extent.

When the lightning receptor installed on the tower head, by increasing the height of the tower, it can not only improve the lightning induction ability of the tower top, but also improve the lightning induction ability of the lightning protection line, and attract the shielding attack near the tower to the tower head and transform it into a counterattack , thereby greatly reducing the siege rate.

8. Install nano-magnetoresistor

Corresponding protection should also be carried out on the incoming line section of the substation. In order to limit the intrusion wave steepness, a nano-magnetoresistor can be installed.

9. Install the line zinc oxide arrester

In order to reduce lightning accidents on lines and improve power supply reliability, installing zinc oxide arresters on lines is a very effective method to reduce lightning accidents on lines. Both theoretical calculation analysis and practice have proved that applying line arresters to lines with strong lightning activities or high soil resistivity and difficulty in reducing grounding resistance can greatly improve the lightning resistance level of lines and reduce the lightning tripping rate of lines, thereby reducing The unplanned power outage time of the line improves the reliability of power supply.

It should be noted that for the foregoing method embodiments, for the sake of simple description, they are expressed as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence. Because of the present invention, certain steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification belong to preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by means of software plus a necessary general-purpose hardware platform, and of course also by hardware, but in many cases the former is Better implementation. Based on such an understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art can be embodied in the form of software products, and the computer software products are stored in a storage medium (such as ROM/RAM, disk, CD) contains several instructions to enable a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in various embodiments of the present invention.

Example 2

According to an embodiment of the present invention, there is also provided a lightning protection device for a power transmission line for implementing the lightning protection method for a power transmission line described above. For the lightning protection method of the line, the lightning protection device for the transmission line provided by the embodiment of the present invention is described in detail below:

2 is a schematic diagram of a lightning protection device for a power transmission line according to an embodiment of the present invention. As shown in FIG. 2 , the lightning protection device for a power transmission line mainly includes an acquisition unit 10, a calculation unit 20, and a setting unit 30, wherein:

The acquisition unit 10 is used to acquire the lightning parameters of the transmission line, wherein the lightning parameters are based on the lightning data accumulated by the operation of the lightning monitoring system, divide the line corridor in the form of a grid, and make statistics, analyze and obtain data that can reflect the different time of the line corridor. , Lightning parameters such as ground flash density of lightning activity characteristics in different regions, cumulative probability distribution of lightning current amplitude, etc.

The calculation unit 20 is used to calculate the lightning protection degree of the base tower of the transmission line according to the lightning parameters, that is, according to the set evaluation standard, combined with the calculation results of the lightning trip rate of the base tower, evaluate the lightning resistance performance of each base tower, and Combined with the lightning activity parameters in the area where the tower is located, the structure of the tower, the insulation configuration, and the characteristics of the topography, the reasons for the flashover of the tower with weak lightning resistance are analyzed.

The setting unit 30 is used to set the lightning protection mode of the transmission line according to the lightning protection degree. Specifically, based on the evaluation results of lightning protection performance, combined with the analysis of the reasons for tower flashover and the characteristics of various lightning protection measures, targeted lightning protection measures and treatment plans were formulated, and after the implementation of the lightning protection transformation plan Calculate the lightning trip rate again to evaluate the effect of lightning protection transformation.

The lightning protection device for the transmission line provided by the embodiment of the present invention obtains the radar parameters, calculates the lightning protection degree based on this, and then sets the lightning protection mode of the transmission line according to the lightning protection degree, so as to realize the comprehensive consideration of the lightning of the transmission line Various factors and characteristics such as activity, line structure, terrain and landform, etc., using the lightning parameters obtained from the statistical analysis of the monitoring data of the lightning monitoring system, lightning protection calculations are carried out for the base towers of the transmission line, reflecting the relative strength of each base tower of a transmission line The strength of the lightning protection performance can effectively help the design and operation departments of transmission lines to take more detailed and targeted lightning protection measures to improve the lightning protection performance of the line, manage the power grid more finely, and solve the problems of transmission lines in the prior art. The problem of low lightning protection performance, and then achieve the effect of improving the safety and stability of transmission lines.

Wherein, the acquisition unit 10 includes an acquisition subunit, the calculation unit 20 includes a calculation subunit, and the acquisition subunit is used to acquire the shielding tripping rate P _r and the counterattack tripping rate P _f of the transmission line. The strike trip rate P _r and the counter strike trip rate P _f are used to calculate the lightning protection degree of the transmission line base tower.

Specifically, the calculation subunit mainly includes first to third search modules, first to third acquisition modules, and a comprehensive module, wherein the first search module is used to find the shielding trip rate from a plurality of first preset index ranges The index range where P _r is located is to obtain the first range; the first acquisition module is used to obtain the degree level corresponding to the first range to obtain the first level; the second search module is used to search from a plurality of second preset index ranges The index range where the counterattack tripping rate P _f is located is to obtain the second range; the second acquisition module is used to obtain the degree level corresponding to the second range to obtain the second level; the third search module is used to obtain the second level from a plurality of third preset indicators Find the index range where the trip rate P is located within the scope to obtain the third range, wherein the trip rate P is the sum of the shielding trip rate P _r and the counterattack trip rate P _f ; the third acquisition module is used to obtain the corresponding value of the third range degree level, to obtain the third level; the comprehensive module is used to integrate the first level, second level and third level, to obtain the lightning protection degree of the transmission line.

In the embodiment of the present invention, as shown in Table 1, multiple first preset index ranges can be set as [0,0.5S _r ), [0.5S _r ,S _r ), [S _r ,1.5S _r ) and [1.5S _r ,∞), multiple second preset index ranges can be set to [0,0.5S _f ), [0.5S _f ,S _f ), [S _f ,1.5S _f ) and [1.5S _f , ∞), multiple third preset index ranges can be set to [0,0.5(S _r +S _f )), [0.5(S _r +S _f ),(S _r +S _f )), [(S _r +S _f ),1.5(S _r +S _f )) and [1.5(S _r +S _f ),∞), wherein, S _r is the first preset parameter, and S _f is the second preset parameter.

Through the above method, the lightning protection degree (that is, the lightning flashover risk) of each base tower of the transmission line is divided into A, B, C, and D, and the relative strength of each tower's shielding and counter-attack lightning protection performance is further improved. express it intuitively. Subsequently, the lightning protection mode of the transmission line can be set according to the level of lightning protection performance, and lightning protection measures can be strengthened for towers with relatively weak wind and lightning performance. Specifically, in the embodiment of the present invention, the following lightning protection measures can be adopted:

1. Reduce the protection angle

With the gradual reduction of the protection angle of the line, the shielding rate of the line shows a downward trend, and reducing the protection angle is a more effective method to reduce the shielding trip rate. However, for existing lines, it is not feasible to change the protection angle of the line, and for towers with a large ground inclination in mountainous areas, the protection angle cannot be greatly reduced due to the limitation of the tower head design, so other effective shielding protection measures should be taken.

2. Strengthen the line insulation level

Improving the insulation level of the line is also a method to enhance the lightning resistance level of the line. By improving the insulation level of the line, the U50% discharge voltage of the insulator can be increased, and the lightning resistance level of the line can be improved.

3. Reduce the tower grounding resistance

Reducing the grounding resistance of towers is a basic anti-counterattack measure for high-voltage transmission lines. Reducing the grounding resistance of towers can reduce the potential of lightning strikes on the top of towers, improve the lightning resistance level of lines, and effectively prevent counterattack accidents. There are many measures to reduce the grounding resistance of towers, such as horizontal extension grounding body, deep-buried grounding electrode, filling with low-resistance materials, and installing conductive grounding modules.

4. Set up the coupling ground wire

There are two main functions of the coupling ground wire: one is to increase the coupling coefficient between the lightning conductor and the conductor, thereby reducing the counterattack of the voltage at both ends of the insulator string and the component of the induced voltage; The shunting function of the tower reduces the voltage that the insulators bear and improves the lightning resistance level of the line. However, it is difficult to erect coupling ground wires. Limited by terrain conditions, the power consumption of line operation will be increased, and trees may need to be felled, which will increase the workload and difficulty of line operation and maintenance, and its economic cost is also high.

5. Set up the bypass ground wire

The erection of the bypass ground wire can enhance the shielding effect on the wires, and has a certain effect of reducing lightning shielding, but it needs to erect additional towers and wires, and the economic cost is very high.

6. Install protection gap

The main function of the protective gap is to protect the insulator from damage through arc flashover when lightning strikes occur, which can reduce the lightning strike accident rate of the line. For existing lines, the installation of parallel gaps will short-circuit some insulators, resulting in a decrease in the insulation level of the line, which in turn leads to an increase in the lightning trip rate.

7. Install wave-blocking lightning-termination device

In domestic and foreign operating experience, the lightning strike distance from the central lightning protection line and its vicinity cause a very small chance of flashover and tripping. Therefore, as long as the tower head of the transmission line and its vicinity are not subjected to lightning strikes, the lightning strike tripping rate of the transmission line will be greatly reduced. . It can be seen that the lightning protection of transmission lines can be attributed to the lightning protection centered on the tower to a large extent.

When the lightning receptor installed on the tower head, by increasing the height of the tower, it can not only improve the lightning induction ability of the tower top, but also improve the lightning induction ability of the lightning protection line, and attract the shielding attack near the tower to the tower head and transform it into a counterattack , thereby greatly reducing the siege rate.

8. Install nano-magnetoresistor

Corresponding protection should also be carried out on the incoming line section of the substation. In order to limit the intrusion wave steepness, a nano-magnetoresistor can be installed.

9. Install the line zinc oxide arrester

In order to reduce lightning accidents on lines and improve power supply reliability, installing zinc oxide arresters on lines is a very effective method to reduce lightning accidents on lines. Both theoretical calculation analysis and practice have proved that applying line arresters to lines with strong lightning activities or high soil resistivity and difficulty in reducing grounding resistance can greatly improve the lightning resistance level of lines and reduce the lightning tripping rate of lines, thereby reducing The unplanned power outage time of the line improves the reliability of power supply.

From the above description, it can be seen that the present invention comprehensively considers various factors and characteristics such as lightning activity, line structure, topography and landform of the transmission line, and adopts the lightning parameters obtained based on the statistical analysis of the monitoring data of the lightning monitoring system. The lightning protection calculation is carried out on a base-to-base basis for the line, which reflects the relative lightning protection performance of each base tower of a transmission line, which can effectively help the design and operation departments of the transmission line to take more detailed and targeted lightning protection measures to improve Line lightning protection performance, more refined management of the power grid, solves the problem of low lightning protection performance of transmission lines in the prior art, and achieves the effect of improving the safety and stability of transmission lines.

Obviously, those skilled in the art should understand that each module or each step of the above-mentioned present invention can be realized by a general-purpose computing device, and they can be concentrated on a single computing device, or distributed in a network formed by multiple computing devices Optionally, they can be implemented with program codes executable by a computing device, so that they can be stored in a storage device and executed by a computing device, or they can be made into individual integrated circuit modules, or they can be integrated into Multiple modules or steps are fabricated into a single integrated circuit module to realize. As such, the present invention is not limited to any specific combination of hardware and software.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. A lightning protection method for transmission lines, characterized in that, comprising: Obtain the lightning parameters of the transmission line; Calculating the lightning protection degree of the transmission line base-to-tower according to the lightning parameters; and The lightning protection mode of the transmission line is set according to the lightning protection degree. 2. lightning protection method according to claim 1, is characterized in that, Obtaining the lightning parameters of the transmission line includes: obtaining the shielding trip rate and the counter-attack trip rate of the transmission line, Calculating the lightning protection degree of the transmission line base-to-tower according to the lightning parameters includes: calculating the base-to-tower lightning protection degree of the transmission line according to the shielding trip rate and the counter-attack trip rate. 3. The lightning protection method according to claim 2, wherein, according to the shielding tripping rate and the counterattack tripping rate, calculating the lightning protection degree of the power transmission line by base tower includes: Searching for the index range of the shielding trip rate from a plurality of first preset index ranges to obtain the first range; Acquiring the degree level corresponding to the first range to obtain the first level; Finding the index range of the counter-attack trip rate from multiple second preset index ranges to obtain the second range; Acquiring the degree level corresponding to the second range to obtain the second level; Searching for the index range where the sum of the shielding trip rate and the counterattack trip rate is located within multiple third preset index ranges to obtain a third range; Acquiring the degree level corresponding to the third range to obtain the third level; and The lightning protection degree of the transmission line is obtained by combining the first level, the second level and the third level. 4. lightning protection method according to claim 3, is characterized in that, The multiple first preset index ranges include [0,0.5S _r ), [0.5S _r ,S _r ), [S _r ,1.5S _r ) and [1.5S _r ,∞), wherein S _r is the first preset parameter, The plurality of second preset index ranges include [0,0.5S _f ), [0.5S _f ,S _f ), [S _f ,1.5S _f ), and [1.5S _f ,∞), wherein S _f is The second default parameter, The multiple third preset index ranges include [0,0.5(S _r +S _f )), [0.5(S _r +S _f ),(S _r +S _f )), [(S _r +S _f ), 1.5(S _r +S _f )) and [1.5(S _r +S _f ),∞). 5. A lightning protection device for transmission lines, characterized in that it comprises: an acquisition unit, configured to acquire lightning parameters of the transmission line; A calculation unit, configured to calculate the lightning protection degree of the transmission line base-to-tower according to the lightning parameters; and A setting unit, configured to set the lightning protection mode of the transmission line according to the lightning protection degree. 6. The lightning protection device according to claim 5, characterized in that, The acquisition unit includes: an acquisition subunit, configured to acquire the shielding trip rate and counter-attack trip rate of the transmission line, The calculation unit includes: a calculation subunit, configured to calculate the lightning protection degree of the power transmission line tower by base according to the shielding trip rate and the counter-attack trip rate. 7. The lightning protection device according to claim 6, wherein the calculation subunit comprises: The first search module is used to search for the index range of the shielding trip rate from multiple first preset index ranges to obtain the first range; The first acquisition module is configured to acquire the degree level corresponding to the first range to obtain the first level; The second search module is used to search for the index range of the counter-attack trip rate from multiple second preset index ranges to obtain the second range; The second acquisition module is configured to acquire the degree level corresponding to the second range to obtain the second level; The third search module is used to find the index range where the sum of the shielding trip rate and the counter-attack trip rate is located within a plurality of third preset index ranges to obtain a third range; A third acquiring module, configured to acquire a degree level corresponding to the third range to obtain a third level; and A synthesis module, configured to synthesize the first level, the second level and the third level to obtain the lightning protection degree of the transmission line. 8. The lightning protection device according to claim 7, characterized in that, The multiple first preset index ranges include [0,0.5S _r ), [0.5S _r ,S _r ), [S _r ,1.5S _r ) and [1.5S _r ,∞), wherein S _r is the first preset parameter, The plurality of second preset index ranges include [0,0.5S _f ), [0.5S _f ,S _f ), [S _f ,1.5S _f ), and [1.5S _f ,∞), wherein S _f is The second default parameter, The multiple third preset index ranges include [0,0.5(S _r +S _f )), [0.5(S _r +S _f ),(S _r +S _f )), [(S _r +S _f ), 1.5(S _r +S _f )) and [1.5(S _r +S _f ),∞).