A method for optimizing the layout of PLP lightning protection for photovoltaic stations

Abstract

The present invention discloses a method for optimizing the layout of PLP lightning protection for photovoltaic stations, and belongs to the field of lightning protection for power systems. The method comprises: determining the size of the protected area required for the photovoltaic station; determining the height of the protected electrical equipment; determining the protection distance of a single PLP device at the protected height; determining the external protection range and the internal protection range when multiple PLP devices are jointly protected; and calculating the optimal PLP layout scheme in combination with each maximum horizontal distance to achieve effective lightning protection for the photovoltaic station. The method of the present invention can be widely used in optimizing the layout of lightning protection for photovoltaic stations.

Description

Technical Field

[0001] The present invention belongs to the field of lightning protection for power systems, and in particular relates to a method for optimizing the layout of PLP lightning protection for photovoltaic stations. Background Art

[0002] Photovoltaic stations are widely distributed and cover a large area. Most of them are installed outdoors and dispersed. Photovoltaic modules, secondary equipment and communication equipment in the field are subject to the risk of direct and indirect lightning strikes. Lightning strikes pose a huge threat to the safe and stable operation of photovoltaic stations and the safety of equipment and personnel. The principle of traditional lightning arresters and lightning rods is to use the tip discharge phenomenon to lead the charge of lightning clouds in the atmosphere to the lightning rod, and discharge in advance, and transmit the lightning current to the ground through its own grounding conductor to avoid direct lightning strikes on the protected objects. Although this method is simple, it has many defects: for example, large current entering the ground causes the ground potential to rise, causing hazards such as equipment counter-voltage, induced lightning overvoltage, and electric shock to people.

[0003] In recent years, the PLP passive plasma lightning protection device has been widely used due to its unique "lightning elimination" principle and the advantage of not needing to lead lightning into the ground. The new lightning protection device, the Plasma Lightning Protector (PLP), has a good effect in lightning protection. It uses the "tip-like effect" to make its own electric field strength under the thundercloud 2 orders of magnitude higher than the protected object, and attracts the thundercloud charge, so that the protected target is in a relatively low electric field safety position. It uses an induction array lightning rod and a dielectric barrier strong ionization composite discharger, and uses the thundercloud electric field to achieve passive strong ionization. The strong ionization discharger generates and radiates high-concentration plasma in both directions from the cloud to the ground, and efficiently neutralizes the thundercloud charge attracted by the lightning rod, solving the fatal problem that the traditional lightning elimination device array needle electric field self-shielding effect suppresses the increase of divergent current and is easily struck by lightning. Attracted by the thundercloud electric field and its induced ground reverse electric field, the positive (negative) ions in the plasma drift upward to neutralize the thundercloud negative (positive) ions above the needle end, and the negative (positive) ions in the plasma drift downward to neutralize the thundercloud induced positive (negative) ions below the needle end, continuously attracting and bidirectionally neutralizing the thundercloud negative (positive) ions and their induced positive (negative) ions in and around the discharger body, causing the capacitor plates equivalent to the thundercloud and the ground to leak electricity efficiently and become a "bad capacitor" which cannot be charged to form a lightning leader and develop into the electric field strength of subsequent breakdown discharge.

[0004] However, the installation and optimal placement of PLP devices cannot simply copy the optimization of lightning rod placement. It is necessary to consider the protection range of a single PLP and the protection range of multiple PLP devices together, and also to select according to the economic efficiency in combination with the protection range of PLP. At present, there is still a lack of optimal placement methods for PLP devices in photovoltaic stations. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for optimizing the layout of PLP lightning protection for photovoltaic stations, comprising:

[0006] Step 1. Measure the area of ​​the photovoltaic site that needs to be protected;

[0007] Step 2: Determine the height of the protected object ;

[0008] Step 3: Calculate the protection distance of a single PLP device , , where the protection angle of the PLP device is 84-86° and the protection radius , h is the installation height of the PLP device;

[0009] Step 4: When a single PLP device cannot protect the entire area of ​​the PV site, two PLP devices are added and the minimum protection height between the two PLP devices is calculated. :

[0010]

[0011] when The maximum distance between two PLPs of equal height can be determined when , P is the correction coefficient considering the influence of PLP height, when h≤30m, P=1; when 30m<h≤120m, ;

[0012] Step 5. If two PLP devices still do not meet the protection requirements, continue to increase to three PLP devices. When the three PLP devices form a triangle, the outer protection range is determined according to the method of two PLP devices, and the inner protection range is determined according to the height of the protected object. , calculate the minimum protection range of each adjacent PLP device ,if only , then the inner protection range can meet the needs;

[0013] Step 6. If the number of PLP devices continues to increase, the protected photovoltaic field will be divided into two or more triangles, and then calculated according to the method of three PLP devices. Refer to Step 3-Step 5 to calculate the protection range of each triangle, and then comprehensively obtain the protection range of n PLP devices, n>3, until the required protection range of the photovoltaic field is met.

[0014] Furthermore, Step 2 determines the height of the protected object When considering the vertical and horizontal dimensions and creepage distance of the outdoor high-voltage power distribution device, if the height of the protected equipment is inconsistent, there is When not unique, take the largest In general, the protected height of photovoltaic panels is 5m, and the protected height of wind turbines is 110m.

[0015] Furthermore, Step 3 obtains the height of the protected object Scope of protection When installing, make the installation height h of PLP less than 30m as much as possible. If the installation height is too high, more wires will be needed to fix the PLP device.

[0016] Furthermore, the Step 4 determines the maximum distance between two equal-height PLPs. When the two devices .

[0017] Furthermore, if the protected range is slightly smaller than the protection area, the method of increasing the installation height of the local PLP device can be adopted to increase the protection range and form the best combination of unequal height PLP groups.

[0018] Furthermore, when three or more PLP devices are installed, a 10% margin can be reserved to avoid calculating whether the local edge area is protected.

[0019] Beneficial effects:

[0020] 1. The maximum distance between multiple PLP devices is determined to maximize the protection range and achieve good economy. Compared with the traditional configuration scheme, the technical and economic efficiency of PLP installation can be achieved.

[0021] 2. When multiple PLP devices work together, the protection range of the middle area is enhanced. This method qualitatively calculates the expansion of the protection range, making up for the deficiency of the original PLP protection range calculation that only calculates the protection range of a single PLP.

[0022] 3. For the optimal layout of any complex terrain, it can be divided into multiple triangular areas for analysis and calculation of the protection range. This method is applicable to any irregular area. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without carrying out creative work.

[0024] Figure 1 It is a diagram of the protection range of two PLPs;

[0025] Figure 2It is a schematic diagram of the first protection scope of the PLP device in Example 1;

[0026] Figure 3 It is a schematic diagram of the second protection scope of the PLP device in Example 1;

[0027] Figure 4 is a schematic diagram of the protection range of the PLP device in Example 2;

[0028] Figure 5 is a schematic diagram of a protected area in Example 3;

[0029] Figure 6 This is a schematic diagram of the first protection scope of the PLP device in Example 3;

[0030] Figure 7 This is a schematic diagram of the second part of the protection scope of the PLP device in Example 3. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Embodiment 1

[0033] Referring to the above method, this embodiment protects a photovoltaic station in a right-angle trapezoidal area with an upper base of 400m, a lower base of 800m, and a height of 400m. First, the trapezoidal area is cut into two triangular areas, and a PLP lightning protection device is arranged in the first triangular area, i.e., the upper left corner. Figure 2 shown.

[0034] For 1-1' section:

[0035] Step 1: Determine the protected height of the photovoltaic panel

[0036] (1)

[0037] Step 2: Given the initial PLP installation height of 15m; according to the formula

[0038] (2)

[0039] The outer protection radius of the PLP device can be determined.

[0040] Step 3, press

[0041] (3)

[0042] The maximum distance between the two devices can be determined, at which the protection range can be increased, the lightning protection requirements of the central area can be met, and a certain margin can be left for the inner area. Figure 1 Shown are the protection ranges of two PLPs.

[0043] like Figure 2 As shown, three PLP devices are arranged, namely ①②③ as shown in the figure, and the three intersecting circles completely protect the triangle.

[0044] like Figure 3 As shown in the figure, the steps of section 2-2' are the same as those of section 1-1'. Similarly, PLP lightning protection devices can be arranged for the second triangular area. According to the calculation, three PLP devices are also arranged. The long side of the hypotenuse of the triangle is 800m. Arranging two PLPs cannot meet the protection requirements. Therefore, one PLP is added at the hypotenuse, for a total of Figure 3 The protection range formed by the four PLPs ④⑤⑥⑦ shown can meet the protection requirements of the second triangular area.

[0045] Embodiment 2

[0046] In this embodiment, a photovoltaic station in an equilateral triangle area with a side length of 900 m is protected, and the method includes the following specific steps:

[0047] Step 1: Determine the protected height of the photovoltaic panel

[0048] (1)

[0049] Step 2: Given the initial PLP installation height of 25m; according to the formula

[0050] (2)

[0051] The outer protection radius of the PLP device can be determined.

[0052] Step 3, press

[0053] (3)

[0054] The maximum distance between the two devices can be determined, at which the protection range can be increased and the lightning protection requirements of the central area can be met.

[0055] like Figure 4 As shown, a total of 3 PLP devices are set up at the points ①②③ marked within the triangle range, so that the equilateral triangle area in this embodiment can be completely protected.

[0056] Embodiment 3

[0057] In this embodiment, a photovoltaic station in a regular hexagonal area with a side length of 500m is protected. The hexagonal area is first cut into four triangular areas. It is easy to know that two right triangles are congruent and two obtuse triangles are also congruent. Therefore, the PLP devices in a right triangle and an obtuse triangle area can be arranged first, such as Figure 6 shown.

[0058] The method comprises the following specific steps:

[0059] Step 1. Determine the protected height of the photovoltaic panel;

[0060] (1)

[0061] Step 2. Given the initial PLP installation height of 15m, according to the formula:

[0062] (2)

[0063] The outer protection radius of the PLP device can be determined.

[0064] Step 3, press the formula:

[0065] (3)

[0066] The protection distance of two PLP devices in a straight line is 400+100×2=600m, and the protection distance of three PLP devices in a straight line is 400×2+100×2=1000m.

[0067] Because the protection range of a single PLP is a circle, when the lengths of each side of the protection area are smaller than the protection distance of the PLP on a straight line, all devices in the protection area will be protected.

[0068] like Figure 6 As shown, for the right triangle area, two PLP devices are sufficient for a side length of 500m, three PLP devices are required for a right side length of 866m, and three PLP devices are also required for a hypotenuse length of 1000m. A total of 5 PLP devices are set up at the ①②③④⑤ points marked within the right triangle. For the obtuse triangle area, the two short sides are both 500m, and two PLPs need to be installed. The long side is 866m long, and three PLP devices are installed. A total of 4 PLP devices are set up at the ⑥⑦⑧⑨ points marked within the obtuse triangle.

[0069] It is easy to see that the layout of the other two triangular areas is exactly the same as the previous two, such as Figure 7 As shown, arranging 18 PLP devices can completely protect the regular hexagonal area.

[0070] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for optimizing the layout of PLP lightning protection for photovoltaic stations. It is characterized in that include: Step 1. Measure the area of ​​the photovoltaic site that needs to be protected; Step 2: Determine the height of the protected object ; Step 3: Calculate the protection distance of a single PLP device , , where the protection angle of the PLP device is 84-86° and the protection radius , h is the installation height of the PLP device; Step 4: When a single PLP device cannot protect the entire area of ​​the PV site, add two PLP devices and calculate the minimum protection height between the two PLP devices. : ； when The maximum distance between two PLPs of equal height can be determined when , P To consider the correction factor of the PLP height, when h≤30m, P =1; when 30m<h≤120m, ; Step 5. If two PLP devices still do not meet the protection requirements, continue to increase to three PLP devices. When the three PLP devices form a triangle, the outer protection range is determined according to the method of two PLP devices, and the inner protection range is determined according to the height of the protected object. , calculate the minimum protection range of each adjacent PLP device ,if only , then the inner protection range can meet the needs; Step 6. If the number of PLP devices continues to increase, the protected photovoltaic field will be divided into two or more triangles, and then calculated according to the method of three PLP devices. Refer to Step 3-Step 5 to calculate the protection range of each triangle, and then comprehensively obtain the protection range of n PLP devices, n>3, until the required protection range of the photovoltaic field is met.

2. According to the photovoltaic station PLP lightning protection optimization layout method of claim 1, It is characterized in that Step 2 determines the height of the protected object If the height of the protected equipment is inconsistent, there is When not unique, take the largest .

3. According to claim 1, a photovoltaic station PLP lightning protection optimization layout method, It is characterized in that Step 3 obtains the height of the protected object Scope of protection When installing, make the installation height h of PLP less than 30m.

4. According to claim 1, a photovoltaic station PLP lightning protection optimization layout method, It is characterized in that Step 4 determines the maximum distance between two PLPs of equal height When the two devices .

5. According to claim 1, a photovoltaic station PLP lightning protection optimization layout method, It is characterized in that The method of increasing the installation height of the local PLP device is adopted to increase the protection range and form the best combination of PLP groups with different heights.

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