JP3399523B2 - Lightning protection method for electrical facilities - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning protection method for all electric facilities including wireless relay stations, advanced information-oriented buildings, high-tech factories, transmission and distribution lines, and information and communication systems. Lightning protection method for protecting electrical equipment such as semiconductor systems from lightning surges.

[0002]

2. Description of the Related Art In a wide range of electric facilities such as wireless relay stations, advanced information-oriented buildings, high-tech factories, transmission lines and information communication systems, lightning protection measures are required to protect electrical equipment such as semiconductor systems from lightning surges. is there. As a measure against this lightning protection, the lightning protection ring ground wire buried in the ground so as to surround the structure containing the electric equipment and the expected lightning point (lightning rod, ridge conductor, etc.) on the top of the structure are insulated. It has been practiced to connect with an electric wire and arrange the insulated electric wire along the inside and outside of the outer wall of the construction (Japanese Patent No. 2055174).

The lightning protection ring ground wire is installed in the ground so as to capture the ground current flowing toward the structure at the initial stage of lightning generation and prevent the ground current from flowing into the structure. In other words, as the thundercloud develops, the charge density on the ground surface also increases, and when the thundercloud side and the ground side are connected by a stepped leader from the thundercloud side, the charge on the wide ground surface passes through the shallow part of the ground and reaches the lightning point. As they gather and rise to neutralize the charges on the thundercloud side, at the beginning of this thunderstorm the lightning ground current is trapped by the lightning loop that wraps around the structure before it reaches the structure, As it flows from the insulated wire to the lightning strike point on the top of the structure,
The structure becomes a Faraday cage in the space where no lightning current flows, and electrical equipment such as semiconductor systems is protected from lightning surges.

[0004]

By the way, an input power supply line of an electric equipment is disposed inside and outside a structure surrounded by a lightning protection ground wire, and a lightning protection transformer is provided between the input power supply wire and the electric equipment. It is designed to prevent the lightning current flowing through the input power line from flowing into the electric equipment by inserting the. However, since the electric charge due to the lightning current blocked by the lightning-resistant transformer goes toward the lightning rod, which is the lightning strike point, a large overvoltage occurs in the lightning-resistant transformer, and this overvoltage not only damages the lightning-resistant transformer but also damages the electrical equipment. There is fear. Therefore, in order to protect the lightning protection transformer, a grounding arrester is provided in the input winding of the lightning protection transformer, and the grounding terminal of this grounding arrester is connected to the grounding pole that is separated from the grounding pole of the electrical equipment. However, there is a possibility that a part of the lightning current discharged to the ground by the ground arrester may damage the electric equipment from the ground electrode of the electric equipment and flow into the lightning rod.

Further, a ring ground wire for reducing surge impedance, which is buried around the structure so as to surround the structure, is connected to the steel frame of the structure, and the ring ground wire and the lightning protection ring ground wire outside thereof are doubled. It is also practiced to protect the electrical equipment in the structure from lightning surges.However, in this case as well, a lightning current may flow into the structure from the input power line, etc., which may make the Faraday cage inside the structure unstable. is there.

Further, the ground current of lightning not only passes through the input power line and the soil, but also when a continuous metal structure such as a gas pipe, a water pipe, and a groove lid is installed inside and outside the structure, Ground currents can also flow into the structure from the structure. Therefore, a part of the structure of the metal structure such as a water pipe is configured with an insulating member so that the lightning current flowing through the metal structure is blocked by the insulating member so as not to flow into the structure. It may flow from the body through the ground into the structure, and in this case also, the Faraday cage formation in the structure may become unstable.

It is an object of the present invention to provide a lightning protection method for an electric facility, in which a Faraday cage made of a steel frame of a structure in which a lightning current does not flow is embodied to stabilize electric facilities inside the structure.

[0008]

In order to achieve the above-mentioned object, the present invention provides a lightning protection ring ground wire buried in the ground so as to surround and surround the structure for housing electrical equipment away from the structure. In an electric facility having a lightning protection device in which a lightning strike point on the structure is connected to the structure by an electric wire arranged in the structure, the input side of a lightning protection transformer inserted into an input power line of the electric facility. The grounding terminal of the lightning arrester installed on the ground and the grounding electrode provided in the ground outside the lightning protection ground wire are connected by an insulated wire.

Here, the lightning protection transformer inserted in the input power line of the electric equipment in the structure is installed inside and / or outside the structure, and the ground arrester on the input side of this lightning protection transformer surrounds the structure. It is connected to a grounding pole provided in the ground outside the flexible lightning protection ring ground wire, and the grounding pole in this case includes the lightning protection ring ground wire itself. The lightning current that passes through a wide range of ground and goes to the lightning strike point of the structure is captured by the lightning protection ring ground wire that circulates around the structure, and flows in from the input power line and from the ground arrester to the lightning protection ground wire. Since the lightning current flowing into the ground outside of the lightning is also captured by the lightning protection ground wire, the lightning current does not flow in the ground inside the lightning protection ground wire, thus stabilizing the Faraday cage inside the structure. As a result, electrical equipment is safely protected from lightning strikes.

In the above-mentioned lightning protection method of the present invention, it is desirable that the separation distance of the ground electrode from the lightning protection ring ground wire is set within a range of 1 m to 30 m. Such a separation distance is selected according to the withstand voltage of an electric device such as a lightning resistant transformer that is protected from a lightning surge by a ground arrester.

Further, according to the present invention, in an electric facility in which the lightning protection transformer is installed outside a structure, a lightning protection ground wire is arranged so as to surround the structure including the installation location of the lightning protection transformer. It is characterized by having done. In other words, the lightning protection transformer is installed either inside or outside the structure, and when the lightning protection transformer is installed outside the structure, the location of the lightning protection transformer outside the structure is inside the lightning protection ring ground line. In this way, the ground arrester of this lightning protection transformer is connected to the ground electrode outside the lightning protection ground wire.

Further, in the present invention, in an electric facility in which the ground electrode of the electric equipment is installed outside the structure, a lightning protection ring ground is arranged so as to flex around the structure including the installation location of the ground electrode of the electric device. It is characterized by arranging lines. The grounding pole of the electrical equipment here is the grounding pole of the switchboard, etc. other than the lightning protection transformer, and when this grounding pole is outside the structure, the lightning protection ring ground wire is arranged so that this grounding pole also flexes. Set up.

Further, in the present invention, in the electric facility in which the input power supply line is an extra-high or high-voltage power supply line, the ground terminal of the ground arrester connected to the extra-high voltage or high-voltage input power line and the lightning protection ring ground line are connected. It is characterized in that the ground electrode provided in the ground outside of the is connected by an insulated wire. In other words, in an electric facility that receives high-voltage power, a ground arrester connected to the input line on the high-voltage side can be used not only when the high-voltage transformer that converts high-voltage or extra-high-voltage power into low-voltage power is outdoors, but also when it is indoors. The connected ground pole is located outside the lightning protection ground wire.

Further, according to the present invention, an insulating structure using an insulator is provided between the lightning protection ring ground wire and the structure, which is a metal structure extending from the outside of the lightning protection ring ground wire to the inside of the structure. And the metal structure outside the lightning protection ground wire is connected to the lightning protection ground wire. In this case, the metal structure is a gas pipe, water pipe, ditch cover, etc., and when lightning current flows into it, it flows into the lightning protection ring ground wire itself, but blocks up to the inside of the lightning protection ring ground wire with an insulating structure part. Faraday cage formation in the construct becomes stable without any inflow.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a lightning protection method for an electric facility according to the present invention will be described in detail below with reference to FIGS.

The structure 1 shown in FIG. 1 is a steel structure.
An electric equipment 4 such as a semiconductor system is housed inside. The lightning protection transformer 3 is inserted between the input power supply line 5 for supplying electric power to the electric equipment 4 and the electric equipment 4, and the ground arrester 6 is connected to the input winding side of the lightning protection transformer 3. A lightning protection ring ground wire 11 in which a wire, for example, a bare wire is buried in the ground so as to surround the structure 1 is arranged, and a lightning point arranged at the top of the lightning protection ring ground wire 11 and the structure 1, for example, The lightning rod 2 is connected by the electric wire 12 to construct a lightning protection device. The electric wire 12 is an insulated electric wire or the like and is arranged along the outer wall of the structure 1 in an insulated state from the steel frame of the structure 1. The lightning protection ground wire 11 is provided with grounding electrodes 13 connected to the lightning protection ground wire 11 and extending downward in the ground at predetermined intervals. This type of ground electrode is a rod-shaped ground electrode in FIG. 1, but a plate-shaped ground electrode is also possible.

Further, the construction 1 in the embodiment shown in FIG.
Is to embed a surge impedance lowering annular ground wire 15 around the structure 1 so as to surround the structure 1,
It is electrically connected to the steel frame of the structure 1. In the existing structure 1 including the ring ground wire 15, the lightning protection ring ground wire 11 is arranged outside the ring ground wire 15 at a distance. The present invention is also applied to an existing structure that does not include the surge impedance lowering annular ground wire, and the surge impedance lowering annular ground wire is omitted in FIGS. 2 to 4.

In the embodiment of FIG. 1, the lightning protection transformer 3 insulates the input power supply line 5 from the electric equipment 4 so that the lightning current flowing from the input power supply wire 5 does not flow to the electric equipment 4. Further, the electric charge existing in a wide range of ground with a polarity opposite to that of the thundercloud is sucked into the lightning protection ring ground line 11 before reaching the structure 1 as shown by the arrow in FIG.
From the electric wire 12 to the lightning rod 2,
The inside of the structure 1 is made into a Faraday cage, and the electric equipment 4 is protected from a lightning surge.

According to the present invention, the ground terminal of the lightning arrester 6 of the lightning protection transformer 3 is connected to the lightning protection ground wire 1 according to the present invention.
1 is connected to a ground electrode 9 provided at an arbitrary position outside 1 by an insulated wire 8. That is, the conventional ground arrester 6
The grounding terminal of 1 was grounded in the vicinity of the structure 1 similarly to the main grounding 10 of the electric equipment 4, but this grounding terminal is connected to the grounding electrode 9 outside the lightning protection ground wire 11. By doing so, the lightning current passing through the ground and heading for the structure 1 is captured by the lightning protection ground wire 11 and flows to the lightning rod 2, and also flows in from the input power supply line 5 as shown by the arrow in FIG. The lightning current flowing through the ground arrester 6 of the lightning resistant transformer 3 is
Flows into the ground outside and is captured by the lightning protection ring ground wire 11.
That is, the lightning current flowing from the distant place into the input power line 5 and flowing to the structure 1 is returned from the ground arrester 6 to the distant place outside the lightning protection ring ground line 11 so as to make a U-turn, and the lightning protection ring ground line 1 is returned.
There is no possibility of flowing in the ground inside the ground 1, so that the Faraday cage inside the structure 1 installed inside the lightning protection ground wire 11 becomes stable.

In the above-mentioned lightning protection method of the present invention, the separation distance of the ground electrode 9 from the lightning protection ring ground wire 11 is 0 m, that is,
A part of the lightning protection ground wire 11 may be the ground electrode 9,
Practically, it is desirable to set within the range of 1 m to 30 m. Such a separation distance is appropriately set based on the withstand voltage of the lightning protection transformer 3, and when the separation distance exceeds 30 m, the installation space of the electric facility becomes large and the installation place of the electric facility is restricted. .

The above embodiment has a structure in which the lightning protection transformer 3 is installed inside the building 1. However, the installation location of this type of lightning protection transformer 3 is often outside the building 1, and In an electric facility in which a lightning protection transformer is installed outside of the building 1, a lightning protection ring wire 11 is arranged so as to surround the structure 1 including an installation location of an external lightning protection transformer (not shown). Set up. That is, when the lightning protection transformer is installed outside the structure 1, the location of the lightning protection transformer outside the structure 1 is set inside the lightning protection ring ground wire 11, and the ground arrester of this lightning protection transformer is connected to the lightning protection ring. Grounding in the ground outside the ground wire 11 stabilizes the Faraday cage inside the structure.

Further, in an electric facility in which a plurality of various ground electrodes of the electric equipment 4 installed inside the structure 1 are installed outside the structure 1, a ground electrode (not shown) is installed outside the structure. The lightning protection ring-shaped ground wire 11 is arranged so as to surround the structure 1 including. In other words, if there is a grounding pole other than the main grounding 10 of the electrical equipment 4 that is installed in the ground outside the structure 1, the lightning protection ring ground should also be bent around the grounding pole outside the structure. A line 11 is provided. By doing this, the structure 1 is
The lightning current directed toward is not captured by the lightning protection ground wire 11 and does not flow to the ground electrode outside the structure of the electric equipment 4, thereby stabilizing the Faraday cage inside the structure.

Further, FIG. 4 shows an extra-high voltage or high voltage substation type electric facility in which the power converted into a low voltage of 100V to 200V by a high voltage transformer such as a pole transformer is supplied to the input power line 5. As described above, the ground terminal of the ground arrester 31 connected to the high voltage side (input side) of the high voltage transformer 30 inserted in the extra high or high voltage input power line 5 is connected to the ground electrode 32 outside the lightning protection ground wire 11. Connect to. That is, in a high-voltage substation type electric facility, if the high-voltage transformer 30 is installed on the ground inside the lightning protection ground wire 11, the ground arrester 31 of the high-voltage transformer 30 is installed outside the lightning protection ground wire 11. When grounded at, the lightning current flowing into the lightning arrester 31 flows into the ground outside the lightning protection ground wire 11 and is then captured by the lightning protection ground wire 11, which causes the electrical equipment 4 in the structure 1 to thunder surge. Protected from. In this case, the ground arrester of the lightning protection transformer 3 on the low voltage side (output side) of the high voltage transformer 30 is not necessarily required.

In addition, as shown in FIGS.
In an electric facility in which a continuous metal structure 20, such as a gas pipe, a water pipe, and a groove cover, is installed, an insulating structure part of an insulator is provided between the lightning protection ring ground wire 11 of the metal structure 20 and the structure 1. Two
1, and the metal structure 20 outside the lightning protection ground wire 11
Is grounded to the lightning protection ring wire 11. For example, the metal structure 20
Is a long metal pipe and is laid from the outer side of the lightning protection ring ground wire 11 to the inside of the structure 1, the insulation pipe is replaced only between the lightning protection ring ground wire 11 and the structure 1 of this metal pipe. To form the insulating structure portion 21. It is desirable that both ends of the insulating structure 21 slightly protrude into the inside of the structure 1 and the outside of the lightning protection ground wire 11 in order to more reliably prevent the flow of lightning current.

That is, when a lightning current flows into the metal tube of the metal structure 20 from a distance from the outside of the lightning protection ground wire 11, this lightning current is captured by the lightning protection ground wire 11 and flows to the lightning rod 2. , Insulation structure 2 up to the inner side of the lightning protection ground wire 11
1 is blocked and does not flow in, which stabilizes the Faraday cage formation in the structure 1, and the metal structure 2
The electrical installation 4 in the structure 1 is reliably protected from lightning surges flowing through zero.

[0026]

According to the present invention, a lightning current that is about to flow from an input power line into a structure containing electric equipment or a metal structure such as a gas pipe or a water pipe will flow into the structure. And the lightning current that is about to flow directly into the structure through the soil are captured by the lightning protection ring ground wire during the flow and flow through the ground inside the lightning protection ground wire. Since it has no Faraday cage inside the structure inside the lightning protection ring ground line, it is highly stable, and it is possible to reliably protect electrical equipment such as semiconductor systems installed in the structure from lightning surges. The lightning protection effect is exhibited.

[0027]

[Brief description of drawings]

FIG. 1 is a perspective view showing an overview of an entire electric facility according to an embodiment of the present invention.

FIG. 2 is a plan view showing an overview of the entire electric facility of FIG.

FIG. 3 is a side view showing an overview of the entire electric facility of FIG.

FIG. 4 is a side view showing an outline of an entire electric facility according to another embodiment.

[Explanation of symbols]

1 construction 2 Lightning strike points, lightning rod 3 Lightning protection transformer 4 electrical equipment 5 Input power line 6 Ground arrester 8 insulated wires 9 Ground pole 11 Lightning protection ring ground line 12 electric wires 15 Ring ground wire for surge impedance reduction 20 Metal structure (gas pipe, water pipe, etc.) 21 Insulation structure 30 high voltage transformer 31 Ground arrester 32 ground pole

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Kudo 3-7-18 Meishin-cho, Amagasaki City, Hyogo Prefecture Otowa Denki Kogyo Co., Ltd. (56) Reference JP-A-11-176591 (JP, A) ) JP-A-8-31668 (JP, A) JP-A-3-86017 (JP, A) JP-A-2-296310 (JP, A) JP-A-6-53056 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H02G 13/00

Claims (4)

(57) [Claims] 1. A lightning protection ring ground wire buried in the ground so that the periphery of a structure accommodating electrical equipment is separated from the structure and flexed, and the lightning point on the structure is the same as the structure. In an electric facility having a lightning protection device connected by an electric wire arranged in a structure, the ground terminal of the lightning arrester installed on the input side of the lightning protection transformer inserted in the input power line of the electric facility and the lightning protection ring A lightning protection method for an electric facility, characterized in that a ground electrode provided in the ground outside the ground wire is connected by an insulated wire. 2. In an electric facility in which the lightning protection transformer is installed outside a structure, a lightning protection ground wire is arranged so as to surround the structure including the installation location of the lightning protection transformer. The lightning protection method for an electric facility according to claim 1. 3. In an electric facility in which the ground electrode of the electrical equipment is installed outside the structure, a lightning protection ground wire is arranged so as to surround the structure including the installation location of the ground electrode. The lightning protection method for an electric facility according to claim 1 or 2, which is characterized. 4. An insulating structure part made of an insulator is provided between the structure and the lightning protection ground wire of the metal structure extending from the outside of the lightning protection ground wire to the inside of the structure. The lightning protection method for an electric facility according to any one of claims 1 to 3, wherein a metal structure outside the lightning protection ground wire is connected to the lightning protection ground wire.