A Design Method and System for Differentiated Configuration of Lightning Protection Equipment

Abstract

The present invention discloses a design method and system for differentially configuring lightning protection devices. The method includes: conducting a whole-device impulse aging test on lightning arresters to obtain the impulse withstand life of lightning arresters under different currents; drawing a lightning strike density distribution map based on the cloud-to-ground flash density in the area where lightning arresters need to be installed, obtaining the lightning strike density data for each section, and calculating the number of lightning strikes suffered by the line within a unit range; obtaining the lightning current amplitude probability formula based on the lightning current amplitude distribution in the area where lightning arresters need to be installed, and obtaining the number of lightning strikes suffered by lightning arresters under different lightning currents; comparing the impulse withstand life under different currents with the number of lightning strikes suffered by lightning arresters under different lightning currents to obtain the number of damaged lightning arresters within the design life; and further obtaining the required impulse withstand life value of the lightning arresters.

Description

Technical Field

[0001] The present invention relates to the technical field of power lightning protection, and particularly to a design method and system for differentially configuring lightning protection devices. Background Art

[0002] Lightning protection devices have been widely used in power systems, and zinc oxide varistors are the core components of lightning protection devices. Due to their excellent non-linear characteristics and tolerance, varistors are widely used in power system lightning protection. Under normal voltage, the varistor is a high-resistance resistor, playing an insulating role. Under lightning overvoltage, the varistor converts to a low resistance, and a large current flows through the varistor to release to the ground. After the lightning overvoltage, the resistance value quickly recovers, and the line resumes insulation.

[0003] A large current flowing through the varistor will generate a large amount of energy inside the varistor, and phenomena such as heating will occur in the varistor. When the impulse current exceeds the tolerance value of the varistor, phenomena such as thermal breakdown, thermal perforation, and rupture will occur. Once rupture occurs, the varistor fragments form an impact force and damage the structure, affecting safe operation.

[0004] Currently, the current-carrying capacity of lightning arresters is 65 kA according to standard requirements. Configuring a lightning arrester with a current-carrying capacity of 100 kA can significantly reduce the damage rate of lightning arresters and improve the lightning protection ability of the line, but the cost is higher than that of 65 kA. There is no effective standard for how to configure lightning arresters with different current-carrying capacities. The existing standard only recommends using 100 kA in multi-thunderstorm areas, and actual operation cannot be quantified, with a large degree of randomness.

[0005] In summary, there is an urgent need to propose a design method for differentially configuring lightning protection devices. Summary of the Invention

[0006] The present invention provides a design method and system for differentially configuring lightning protection devices to solve the technical problem of non-standard configuration of current-carrying capacity in existing lightning protection settings.

[0007] To solve the above technical problem, the technical solution proposed by the present invention is as follows:

[0008] A design method for differentially configuring lightning protection devices includes the following steps:

[0009] S1: Conduct a whole-device impulse aging test on the lightning arrester to obtain the impulse withstand life S of the lightning arrester at different currents;

[0010] S2: Draw a lightning strike density distribution map according to the ground flash density of the area where the lightning arrester needs to be installed to obtain the lightning strike density data N of each section, and calculate the number of times the line is struck by lightning within a unit range;

[0011] S3: Obtain the lightning current amplitude probability formula f according to the lightning current amplitude distribution in the area where lightning arresters need to be installed. The number of lightning strikes suffered by the lightning arrester under different lightning currents is n = f × the number of lightning strikes on the line within the unit range;

[0012] S4: Compare the impulse withstand life S under different currents and the number of lightning strikes n suffered by the lightning arrester under different lightning currents to obtain α the number of damaged lightning arresters within [design life] years;

[0013] S5: The design of the lightning arrester in this area is α the number of damages within [design life] years is not greater than w, then m > w, and the required impulse withstand life value of the lightning arrester is obtained.

[0014] Preferably, the number of lightning strikes on the line within the unit range is obtained through the following steps:

[0015] The lightning attracting width is equal to 4 times the conductor height plus the distance b between the lightning protection line and the conductor:

[0016] Y = 4h + b (1)

[0017] The number of lightning strikes on the line within the unit range is: the line length within the unit range · Y · N.

[0018] Preferably, α the number of damaged lightning arresters within [design life] years, the calculation formula is as follows:

[0019] m = α ·n - S

[0020] where m is α the number of damaged lightning arresters within [design life] years (usually the design life).

[0021] The present invention also provides a computer system, including a memory, a processor, and a computer program stored on the memory and operable on the processor. When the processor executes the computer program, the steps of any of the above methods are implemented.

[0022] The present invention has the following beneficial effects:

[0023] The design method of the lightning protection equipment with differential configuration of the present invention analyzes the impulse life of the whole lightning arrester instead of the resistor chip, which is closer to the actual situation; through comprehensive analysis of the impulse life and the lightning impact situation suffered by the lightning arrester, the operating life of the lightning arrester under different regions and different lightning strike conditions can be obtained; by comparing and analyzing the operating life of the lightning arrester obtained from experiments and calculations with the design life, the current-carrying capacity that the lightning arrester should possess under this design life can be obtained, which can effectively guide the differential configuration of lightning protection equipment.

[0024] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The following will refer to the accompanying drawings to further elaborate on the present invention in detail. Description of the Drawings

[0025] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0026] Figure 1 is a flowchart of the design method of the lightning protection device with differential configuration in the preferred embodiment of the present invention. Detailed Embodiments

[0027] The following will elaborate on the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the claims.

[0028] Figure 1 is a flowchart of the design method of the lightning protection device with differential configuration referred to in this embodiment.

[0029] See Figure 1 , the design method of the lightning protection device with differential configuration of the present invention includes the following steps:

[0030] S1: Conduct a full-impulse aging test on the lightning arrester to obtain the impulse withstand life S(I) of the lightning arrester under different currents;

[0031] (1)

[0032] S2: Draw a lightning strike density distribution map according to the cloud flash density in the area where the lightning arrester needs to be installed, and obtain the lightning strike density data of this section as 5 times / (km 2 .a).

[0033] The lightning attraction width is equal to 4 times the conductor height plus the distance between the shield wire and the conductor:

[0034] Y = 4h + b (2)

[0035] There is no shield wire for 10 kV, so the lightning attraction width is equal to 4 times the conductor height, and it can be obtained that the number of lightning strikes on the line within 100 km is 20 times.

[0036] S3: Obtain the lightning current amplitude probability formula f(I) according to the lightning current amplitude distribution in the area where the lightning arrester needs to be installed. The number of lightning strikes on the lightning arrester under different lightning currents is f(I)·L·Y·N;

[0037] (3)

[0038] Among them, L is the actual length of the line in the area where the lightning arrester is to be installed. The lightning current amplitude probability formula f(I) is the probability that the current appears in the section [I - 5, I + 5].

[0039] S4: By comparing S(I) and n, the number of damaged lightning arresters on this line within 1 - 10 years can be obtained, as shown in Table 1.

[0040] Table 1 Number of Damaged Lightning Arresters on the Line

[0041]

[0042] S5: If the design life of the lightning arrester in this area is that the number of damaged ones within 10 years is not more than 53, then the current - carrying capacity design of the lightning arrester meets the requirements. If the number of damaged ones within 10 years of the design life is less than 20, then the current - carrying capacity needs to be further increased.

[0043] The present invention also provides a computer system, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of any of the above - mentioned embodiments are implemented.

[0044] In summary, the present invention analyzes the impulse life of the whole lightning arrester instead of the varistor, which is closer to the actual situation; through comprehensive analysis of the impulse life and the lightning strike situation suffered by the lightning arrester, the operating life of the lightning arrester under different regions and different lightning strike conditions can be obtained; based on the operating life of the lightning arrester obtained from experiments and calculations, and through comparative analysis with the design life, the current - carrying capacity that the lightning arrester should possess under this design life can be obtained, which can effectively guide the differential configuration of lightning protection equipment.

[0045] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A design method for differentially configured lightning protection equipment, characterized in that, It includes the following steps: S1: Conduct a whole-impulse aging test on the arrester to obtain the impulse withstand life S of the arrester under different currents; S2: Draw a lightning strike density distribution map according to the cloud-to-ground flash density in the area where the arrester needs to be installed, obtain the lightning strike density data N for each section, and calculate the number of lightning strikes on the line within the unit range; S3: Obtain the lightning current amplitude probability formula f according to the lightning current amplitude distribution in the area where the arrester needs to be installed. The number of lightning strikes on the arrester under different lightning currents is n = f · the number of lightning strikes on the line within the unit range; S4: Compare the impulse withstand life S under different currents and the number of lightning strikes n suffered by the arrester under different lightning currents to obtain α the number of arrester damages m within [specific years], and the calculation formula is as follows: m = α ·n - S; S5: If α the number of times m that the lightning arrester is damaged within α years is not greater than the designed life w of the lightning arrester in this area within years, then the current-carrying design of the lightning arrester meets the requirements; when m > w, the current-carrying capacity of the lightning arrester needs to be further increased.

2. The design method for differentially configured lightning protection equipment according to claim 1, characterized in that, The number of lightning strikes on the line within the unit range is obtained through the following steps: The lightning attracting width is equal to 4 times the conductor height plus the distance b between the shield wire and the conductor: Y = 4h + b (1) The number of lightning strikes on the line within the unit range is: the line length within the unit range · Y · N.

3. A computer system, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method described in any one of claims 1 to 2 above.

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