A method for determining the protection range based on the principle of plasma lightning arrester charge accumulation and lightning elimination

Abstract

The present application relates to the technical field of relay protection control of power systems, and in particular to a method for determining the protection range based on the principle of concentrated charge and lightning elimination of plasma lightning arresters. The method comprises: measuring the installation height, protection angle and height of the protected object of the PLP; calculating the complementary angle value of the protection angle, and calculating the tangent value of the complementary angle value; calculating the protection radius corresponding to the height of the protected object and the maximum protection radius on the ground according to the installation height, the tangent value and / or the height of the protected object; determining the protection range of the PLP according to the protection radius and the maximum protection radius on the ground. It aims to solve the problem of how to accurately calculate the protection range of a plasma lightning arrester.

Description

Technical Field

[0001] The present application relates to the technical field of relay protection control of power systems, and in particular to a method for determining a protection range based on the charge accumulation and lightning elimination principle of a plasma lightning arrester. Background Art

[0002] Plasma Lightning Protector (PLP) is a lightning protection device that has been widely used in recent years. Its protection angle can even reach 10 to 14 times or more in high-altitude areas. Its principle is to ionize the air around the device to produce high-concentration ions to neutralize the thundercloud charge and its induced charge on the ground, so that the equivalent electrode plate between the thundercloud and the ground becomes a bad capacitor with leakage and cannot be fully charged. Unlike traditional lightning protection devices that lead lightning into the ground, PLP devices do not generate induced overvoltage. In the distorted electric field range formed within its protection angle range, the generated ions will diverge upward to offset the negative (positive) charge that develops downward from the thundercloud electric field ionization, and diverge downward to offset the positive (negative) charge that develops upward from the ionization of the ground or the protected object, so that the field strength in this range is weakened, effectively suppressing the formation and development of conductivity and suppressing the lightning strike caused by it.

[0003] Traditional protection range calculation methods such as the rolling ball method and the broken line method are mainly used to calculate the protection range of lightning rods or lightning conductors. The calculation is based on the lightning rod lightning induction principle and calculates the protection range through the final jump distance of the lightning leader, that is, the strike distance.

[0004] However, since PLP does not have a lightning-attracting effect, the protection range calculation of traditional lightning arresters is not completely applicable to PLP. In actual working conditions, the farther away from PLP, the lower its protection capability. The farther along the protection angle, i.e., the asymptote, the worse its protection capability is. It does not always maintain a linear relationship. When the traditional method is used to calculate the protection range, the protected objects at the edge of the protection range will still be at risk of being struck by lightning.

[0005] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0006] The main purpose of this application is to provide a method for determining the protection range based on the charge aggregation and lightning elimination principle of a plasma lightning arrester, aiming to solve the problem of how to accurately calculate the protection range of a plasma lightning arrester.

[0007] To achieve the above-mentioned purpose, the present application provides a method for determining a protection range based on the charge accumulation and lightning elimination principle of a plasma lightning arrester, the method comprising:

[0008] Measure the installation height, protection angle and height of the protected object of the PLP;

[0009] Calculating the complementary angle value of the protection angle, and calculating the tangent value of the complementary angle value;

[0010] Calculate the protection radius corresponding to the height of the protected object and the maximum protection radius on the ground according to the installation height, the tangent value and / or the height of the protected object;

[0011] Determining a protection range of the PLP according to the protection radius and the maximum ground protection radius;

[0012] Wherein, the expression of the protection radius is:

[0013]

[0014] The expression of the maximum ground protection radius is:

[0015]

[0016] In the formula, For height The protection radius at the point, R is the maximum protection radius on the ground, is the height of the protected object, h is the installation height, and m is the complementary angle of the PLP protection angle The tangent value of , n=m+1.

[0017] Optionally, the expression of the protection radius is derived from an equivalent hyperbolic equation, and the expression of the equivalent hyperbolic equation is:

[0018]

[0019] In the formula, , .

[0020] Optionally, the process of constructing the equivalent hyperbolic equation includes:

[0021] S1, establish the equivalent hyperbolic equation and its asymptote model with the vertex of the PLP installation:

[0022]

[0023]

[0024]

[0025] In the formula, a is the length of the real semi-axis of the hyperbola equation, b is the length of the imaginary semi-axis of the hyperbola equation, and c is the distance from the focus to the origin;

[0026] S2, the complementary angle of the protection angle is equal to the slope angle of the hyperbola asymptote, that is ,get:

[0027]

[0028] S3, order , that is, the focal distance is equal to the installation height of PLP, then:

[0029]

[0030] S4, order , then the expressions of a and b when the installation height is h are calculated as:

[0031]

[0032] S5, substitute a and b into , we get the equivalent hyperbolic equation:

[0033] .

[0034] Optionally, the maximum ground protection radius is half of the path of the equivalent hyperbolic equation, and the expression of the path is:

[0035] .

[0036] Optionally, the protection angle of the PLP is associated with the altitude, air density, humidity, and temperature of the PLP.

[0037] Optionally, the protection angle ranges from 84° to 86°.

[0038] This application has at least the following technical effects:

[0039] 1. By establishing an equivalent hyperbolic model for the charge removal principle and range in thunderclouds and ground electric fields during the actual working process of PLP, the calculated protection range of plasma lightning arrester is closer to reality;

[0040] 2. By accurately calculating the protection range of the plasma lightning arrester, when determining the protection range according to the PLP protection angle, some margin is reserved for the protected objects at the edge of the protection range to avoid lightning strikes on the protected objects at the edge of the protection range. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a flow chart of the first embodiment of the method for determining the protection range based on the charge accumulation and lightning elimination principle of the plasma lightning arrester of the present application;

[0042] Figure 2 This is a schematic diagram of the PLP protection range involved in the embodiment of the present application;

[0043] Figure 3 A top view of a single PLP protection range under a hyperbolic model according to an embodiment of the present application;

[0044] Figure 4 Schematic diagram of an equivalent hyperbolic model of the PLP protection range involved in an embodiment of the present application.

[0045] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0046] In order to better understand the above technical solution, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0047] First embodiment

[0048] Reference Figure 1 In the first embodiment, the method for determining the protection range based on the principle of plasma lightning arrester charge accumulation and lightning elimination includes the following steps:

[0049] Step S10, measuring the installation height, protection angle and height of the protected object of the PLP;

[0050] In this embodiment, the installation height of the PLP refers to the height from the bottom to the top of the PLP after it is installed in the lightning protection field, the protection angle refers to the angle between the lightning protection wire and the conductor and the vertical line, and the height of the protected object refers to the height of the protected object itself.

[0051] Step S20, calculating the complementary angle value of the protection angle, and calculating the tangent value of the complementary angle value;

[0052] After measuring the installation height, protection angle and height of the protected object of the PLP, the protection angle is set to , the remaining angle values , the tangent value is .

[0053] Step S30, calculating the protection radius corresponding to the height of the protected object and the maximum protection radius on the ground according to the installation height, the tangent value and / or the height of the protected object;

[0054] After the installation height, the tangent value and the height of the protected object are obtained, the protection radius corresponding to the height of the protected object and the maximum protection radius on the ground are calculated according to the installation height, the tangent value and / or the height of the protected object.

[0055] The expression of protection radius is:

[0056]

[0057] The expression of the maximum ground protection radius is:

[0058]

[0059] In the formula, For height The protection radius at is the height of the protected object, h is the installation height, and m is the complementary angle of the PLP protection angle The tangent value of , n=m+1.

[0060] Step S40, determining the protection range of the PLP according to the protection radius and the maximum ground protection radius;

[0061] After calculating the protection radius and the maximum ground protection radius, the protection range of the PLP can be determined based on these two radii.

[0062] Specifically, refer to Figure 2 A schematic diagram of the PLP protection range is shown, and Figure 3 The top view of the protection range of a single PLP under the hyperbolic model is shown. The PLP distorts the electric field shape through the "needle tip array" on its surface, which increases the surrounding electric field strength and forms strong ionization. The generated ions will diverge upward to offset the negative (positive) charge ionized by the thundercloud electric field, and diverge downward to offset the positive (negative) charge generated by the ionization of the ground or the protected object. The distorted shape of the electric field and the charge dissipation range can be approximately equivalent to the curve envelope range of the hyperbola equation, which is a structure that is approximately symmetrical up and down on the horizontal plane where the PLP vertex is located.

[0063] The protection range corresponding to the protected object depends on whether it is within the protection circle formed by the protection radius at the height of the protected object and the maximum protection radius on the ground. Therefore, by calculating the protection radius at the height of the protected object on the PLP and the maximum protection radius on the ground, it can be determined whether the protected object is within the protection range formed by the PLP.

[0064] It should be noted that the expression of the protection radius is derived from the equivalent hyperbolic equation, and the expression of the equivalent hyperbolic equation is:

[0065]

[0066] In the formula, , ;

[0067] After transformation, we can get .

[0068] Further, for how to obtain the equivalent hyperbolic equation, refer to Figure 4 The schematic diagram of the equivalent hyperbolic model of the PLP protection range is shown, and the construction process is as follows:

[0069] S1, establish the equivalent hyperbolic equation and its asymptote model with the vertex of the PLP installation:

[0070]

[0071]

[0072]

[0073] In the formula, a is the length of the real semi-axis of the hyperbola equation, b is the length of the imaginary semi-axis of the hyperbola equation, and c is the distance from the focus to the origin;

[0074] S2, the complementary angle of the protection angle is equal to the slope angle of the hyperbola asymptote, that is ,get:

[0075]

[0076] S3, order , that is, the focal distance is equal to the installation height of PLP, then:

[0077]

[0078] S4, order , then the expressions of a and b when the installation height is h are calculated as:

[0079]

[0080] S5, substitute a and b into , we get the equivalent hyperbolic equation:

[0081] .

[0082] It should be noted that the maximum ground protection radius is half of the path of the equivalent hyperbolic equation, that is:

[0083]

[0084] The expression of the path is:

[0085]

[0086] In addition, optionally, in this embodiment, the protection angle of the PLP is associated with the altitude, air density, humidity, and temperature of the PLP. In some specific embodiments, the protection angle has a value range of 84° to 86°.

[0087] Second embodiment

[0088] Based on the first embodiment, in some specific implementations, the PLP protection angle is set to , , the installation height is h=20m, then the solution is:

[0089] a 2 =4.35,b 2 =395.65.

[0090] Substituting a and b into the expression of the maximum ground protection radius R, we get R=189.7m.

[0091] The traditional calculation formula for the maximum ground protection radius is:

[0092]

[0093] Compared with the original calculated installation height of 200m, a margin of about 5.15% is retained.

[0094] Furthermore, the height of the protected object is h x =10m, substitute it into the expression of protection radius, and we get:

[0095] R x =93.27m

[0096] The traditional radius calculation formula for the height of the protected object is:

[0097]

[0098] At this height, a margin of 6.73% is retained compared to the original 100m.

[0099] It should be noted that, although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0100] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for determining the protection range based on the principle of plasma lightning arrester charge accumulation and lightning elimination, characterized in that: The method comprises the following steps: Measure the installation height, protection angle and height of the protected object of the PLP; Calculating the complementary angle value of the protection angle, and calculating the tangent value of the complementary angle value; Calculate the protection radius corresponding to the height of the protected object and the maximum protection radius on the ground according to the installation height, the tangent value and / or the height of the protected object; Determining a protection range of the PLP according to the protection radius and the maximum ground protection radius; Wherein, the expression of the protection radius is: ； The expression of the maximum ground protection radius is: ； In the formula, For height The protection radius at the point, R is the maximum protection radius on the ground, is the height of the protected object, h is the installation height, and m is the complementary angle of the PLP protection angle The tangent value of ,n=m 2 +1.

2. The method according to claim 1, characterized in that The expression of the protection radius is derived from the equivalent hyperbolic equation, and the expression of the equivalent hyperbolic equation is: ； In the formula, , .

3. The method according to claim 2, characterized in that The construction process of the equivalent hyperbolic equation includes: S1, establish the equivalent hyperbolic equation and its asymptote model with the vertex of the PLP installation: ； ； ； In the formula, a is the length of the real semi-axis of the hyperbola equation, b is the length of the imaginary semi-axis of the hyperbola equation, and c is the distance from the focus to the origin; S2, the complementary angle of the protection angle is equal to the slope angle of the hyperbola asymptote, that is , where θ is the protection angle, we get: ； S3, order , that is, the focal distance is equal to the installation height of PLP, then: ； S4, order , then the expressions of a and b when the installation height is h are calculated as: ； S5, substitute a and b into , we get the equivalent hyperbolic equation: 。 4. The method according to claim 3, characterized in that The maximum ground protection radius is half of the path of the equivalent hyperbolic equation, and the expression of the path is: 。 5. The method according to claim 1, characterized in that The protection angle of the PLP is associated with the altitude, air density, humidity, and temperature at which the PLP is located.

6. The method according to claim 5, characterized in that The protection angle ranges from 84° to 86°.

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