JP2019004321A - Improvement method of lightning protection performance - Google Patents

Abstract

To provide an improvement method of lightning protection performance capable of preventing entry/inflow of a surge current into an electric circuit of an antenna side facility even when direct lightning strikes the antenna.SOLUTION: In a communication device that includes a photoelectric conversion unit 20 on the antenna side above a tower as an antenna side facility installed in the tower and a photoelectric conversion unit 10 on the wireless device side in a station building as a wireless device side facility installed outside the tower, a member having an electrical insulation performance is interposed between a module 21 or the like constituting the photoelectric conversion unit 20 on the antenna side and a casing for storing the module 21 and the like and installed in the tower.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for improving lightning resistance. More specifically, the present invention relates to a technique suitable for application to an antenna-side facility of an optical radio wave communication apparatus having a radio device-side facility and an antenna-side facility.

  Wireless communication has an excellent feature that communication is not interrupted for a long time due to disconnection, which is a concern in wired communication such as an optical fiber. Microwave radio has a parabolic antenna with a diameter of about 3 to 4 m installed on a steel tower and is facing each other to achieve communication of about several tens of kilometers, maintaining a stable communication line even in the event of a disaster such as an earthquake. It is a communication facility that can.

  Microwave wireless communication, which is a wireless communication technology between two points, is basically configured to perform line-of-sight communication with two parabolic antennas facing each other, and the antenna (in other words, aerial line) is a high tower such as a steel tower. It is attached to the place. In addition, when line-of-sight communication cannot be secured due to geographical restrictions, communication is often realized via a wireless relay station installed at the summit or mountainside. That is, a microwave radio equipment for performing microwave radio communication requires a high building such as a steel tower, and the relay station is constructed at a high place. For this reason, the microwave radio equipment is equipment that is easily subjected to lightning, and is easily damaged by lightning. In addition, in recent years, withstand voltage of equipment has been decreasing due to digitalization of communication facilities and introduction of systems using general-purpose communication devices. In other words, there is a need for improved lightning resistance.

  In the case of a facility configuration that has a tower with an antenna attached and a station building with a communication device, the specific contents of the equipment damage caused by lightning are mostly the surge current caused by the direct lightning strike on the tower. It passes through the tower leg and flows to the tower foundation, and a part is diverted to the feed line (waveguide). The current that flows to the grounding system of the tower causes a rise in the ground potential, creating a potential difference between the grounding system of the building and the grounding of the distribution line far away, and lightning occurs in various metal cables that connect them. A surge current is generated. An increase in ground potential can also cause breakdown of the equipment. Surge current that flows through ground bus bars and reinforcing bars near the floor of the office building causes inductive surges to the power cables and metal communication cables connected to the equipment, leading to the breakdown of weak voltage-resistant parts. In this way, lightning surge current enters (in other words, flows in) from many paths such as waveguides, ground lines, distribution lines, and steel frames of buildings. Not only power supply circuits and security devices, but also various devices.

  As a lightning protection design for microwave radio equipment, replace one of the main invasion paths of lightning surge current by replacing the waveguide between the antenna side equipment and the station side equipment of the microwave radio equipment with an optical fiber. It is possible to remove it. That is, in the equipment configuration where the antenna side equipment installed near the parabolic antenna at the top of the tower and the communication equipment installed in the station building are directly connected by the waveguide, surge current caused by lightning strike on the tower A part is diverted to the waveguide. Since the waveguide serves as a main path for carrying a large lightning surge current to the vicinity of the communication device in the office building, if this portion can be removed, it is effective for improving the lightning resistance. The outline of the surge current path when the waveguide between the antenna side equipment and the station side equipment is replaced with an optical fiber is as shown in FIG. 7, and the intrusion path from the waveguide is removed. Since it is possible to reduce the lightning surge current entering the station building and the communication machine room, it is possible to reduce the damage caused by the lightning strike on the station side equipment.

  When the waveguide between the antenna-side equipment and the station-side equipment is made into an optical fiber, the part connected by the waveguide is replaced with an optical fiber, and bidirectional for transmitting and receiving radio signals. Since communication is required, an optical / electrical (also denoted as “O / E”) converter and an electrical / optical (also denoted as “E / O”) converter are arranged at both ends of the optical fiber. Can be considered. Note that the existing antenna can be used as it is. In addition, since an O / E conversion unit and an E / O conversion unit are also required on the steel tower side (that is, the antenna side) that is a lightning strike point, it is important to prevent a lightning strike from occurring in this portion. . And in order to exclude the induction | guidance | derivation by the surge current used as the cause of a failure of an O / E conversion part and an E / O conversion part, it is desirable to set it as the structure which does not use a metal cable. In view of this, it is conceivable to employ optical power feeding using an optical fiber in order to ensure electrical insulation for the power line of the device. In addition to this method, as a power supply method capable of electrical insulation, a configuration in which solar power generation and a storage battery are used together, a wireless power feeding technology, and the like can be cited as candidates. By applying the above-described configuration, the metal cable is not connected to the O / E conversion unit and the E / O conversion unit on the antenna side, and electrical insulation can be ensured.

  As a conventional method for improving the lightning resistance performance of the microwave radio equipment, as a method of removing the surge current invasion via the waveguide connecting the antenna side equipment and the radio equipment in the office building, There are communication systems that use optical fibers instead. This communication system has equipment on the wireless device side and equipment on the antenna side, and as the equipment on the wireless device side, an electrical signal as a transmission signal output from the wireless device is input and the electrical signal is converted into an optical signal. An optical modulation unit that outputs, an optical amplifier that amplifies the light intensity of the optical signal as a transmission signal output from the optical modulation unit, and an optical power transmission unit that receives light and transmits light, As an antenna-side equipment, an optical detector connected to an optical amplifier and an optical fiber and that converts an optical signal as a transmission signal transmitted by the optical fiber into an electric signal, and an optical fiber that is connected to the optical power transmission unit by the optical fiber. An optical power receiving unit that receives light transmitted from the power transmitting unit and converts it into electric power, reduces the carrier frequency component of the optical signal modulated by the optical modulation unit, and receives optical power. Power converted by the Department is to be supplied to the optical detector (Patent Document 1).

  In the communication system disclosed in Patent Document 1, the antenna-side equipment and the station-side radio apparatus are connected by utilizing “optical radio wave fusion technology”, which is a technology for transmitting a radio signal through an optical fiber by analog modulation of light. The optical waveguide is replaced with an optical fiber, an optical / electrical converter and an electrical / optical converter are arranged at both ends of the optical fiber, and an optical fiber is used to supply power to the electrical circuit of the antenna side equipment. By adopting power supply and eliminating the power supply line, a metal cable is not used.

JP 2015-27020 A

  However, since the optical-wave fusion communication device of Patent Document 1 is configured not to use a waveguide, which is a main path of surge current that invades into the building, to the surge building that passes through the waveguide. Although it is possible to protect the equipment in the station from lightning strikes by removing the intrusion of the building, it is easy to receive lightning strikes. Current intrusion cannot be eliminated. For this reason, it is difficult to say that it is perfect as a lightning protection design for a communication device that uses optical wave fusion technology.

  Therefore, the present invention provides an electrical circuit of the antenna-side equipment (in other words, various modules constituting the antenna-side equipment; specifically, for example, an optical / electrical converter or an electrical / optical device) even when a direct lightning strike occurs on the antenna. It is an object of the present invention to provide a method for improving lightning resistance capable of preventing surge current from entering / inflowing into a converter.

  In order to achieve such an object, the lightning resistance improvement method of the present invention is an antenna side of a communication device configured to have an antenna side equipment installed on a steel tower and a radio equipment side equipment installed outside the steel tower. A member having electrical insulation performance is interposed between a module constituting the facility and a housing that stores the module and is installed on the steel tower.

  Further, the method for improving the lightning resistance performance of the present invention is a module that constitutes an antenna-side facility of a communication device configured to have an antenna-side facility installed on a steel tower and a radio device-side equipment installed outside the tower. And a member having electrical insulation performance is interposed between the casing installed on the steel tower and the steel tower.

  Therefore, according to these methods for improving lightning resistance, a member having electrical insulation performance is interposed on the route from the tower base to the ground after passing through the module from the antenna. Intrusion / inflow of surge current into the module is prevented even when lightning occurs.

  In the lightning resistance improvement method of the present invention, the member having electrical insulation performance may be formed in a mat shape and sandwiched between a module mounting plate to which the module is mounted and the housing. In this case, the lightning resistance of the antenna-side equipment can be improved with a relatively simple configuration and structure.

  Further, the method for improving the lightning resistance of the present invention is such that a member having electrical insulation performance is formed as an electrical insulation spacer and is partially installed between a module mounting plate to which the module is attached and the housing. Also good. In this case, the lightning resistance of the antenna-side equipment can be improved with a relatively simple configuration and structure.

  In the lightning resistance improvement method of the present invention, the member having electrical insulation performance may be formed in a plate shape as a module mounting plate to which the module is attached. In this case, the lightning resistance of the antenna-side equipment can be improved with a relatively simple configuration and structure.

  In the lightning resistance improvement method of the present invention, the member having electrical insulation performance may be formed as a fixture for attaching the casing to the steel tower. In these cases, the lightning resistance of the antenna-side equipment can be improved with a relatively simple configuration and structure.

  In the lightning resistance improvement method of the present invention, the member having electrical insulation performance may be formed as a case support member that is provided on the steel tower and to which the case is attached. In these cases, the lightning resistance of the antenna-side equipment can be improved with a relatively simple configuration and structure.

  According to the lightning resistance improvement method of the present invention, it is possible to prevent the surge current from entering / inflowing into the module even when a direct lightning strike occurs on the antenna. Therefore, it is possible to improve the lightning resistance performance of the antenna-side equipment. As a result, the stability and reliability of the communication apparatus can be improved.

  In the lightning resistance improvement method of the present invention, the member having electrical insulation performance is formed in a mat shape, formed as an electrical insulation spacer, formed in a plate shape as a module mounting plate, or formed as a fixture. Or, if it is formed as a case support member, it can improve the lightning resistance performance of the antenna-side equipment with a relatively simple configuration and structure, so as a technology for improving the lightning resistance performance of the communication device It becomes possible to improve the versatility.

It is a figure which shows the example of a structure of the communication system and apparatus with which this invention can be applied. It is a conceptual diagram explaining the path | route of the shunt current shunt | shrinking at the time of the direct lightning strike to an antenna. It is a conceptual diagram explaining the example of the aspect of the electrical insulation in the improvement method of the lightning resistance performance which concerns on this invention. It is a conceptual diagram explaining the other example of the aspect of the electrical insulation in the improvement method of the lightning resistance performance which concerns on this invention. It is a conceptual diagram explaining the further another example of the aspect of the electrical insulation in the improvement method of the lightning resistance performance which concerns on this invention. It is a conceptual diagram explaining the further another example of the aspect of the electrical insulation in the improvement method of the lightning resistance performance which concerns on this invention. It is a figure explaining the outline | summary of the lightning surge electric current path | route at the time of replacing the waveguide in a microwave radio communication facility (specifically, a steel tower and a station building) with the optical fiber.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.

  1 to 6 show an example of an embodiment of a method for improving lightning resistance according to the present invention.

(1) Configuration of Communication Facility and Communication System / Device In the present embodiment, a facility configuration having a station building and a steel tower will be described as an example, as in the example shown in FIG.

  Specifically, as in the example shown in FIG. 7, the radio / electricity / electricity / optical conversion unit (symbol 10 in FIG. 1) on the side of the wireless device installed in the station building and the upper part of the tower. The optical / electrical / electrical / optical conversion unit (symbol 20) on the antenna side is provided, and optical fibers (symbols 2A to 2D) are laid between these two optical / electrical / electrical / optical conversion units. Is done. The optical / electrical / electrical / optical conversion unit in the present invention converts an optical signal into an electrical signal or converts an electrical signal into an optical signal. In the description of the present invention, the light / electricity / electricity / light conversion unit is also simply referred to as “photoelectric conversion unit”.

  In the communication system of the present embodiment, an optical radio wave fusion technique, which is an optical analog transmission technique, is used for wireless signal transmission.

  FIG. 1 shows an example of the configuration of a communication system / device to which the present invention can be applied in the same facility configuration as the example shown in FIG.

  The communication system shown in FIG. 1 is configured as an optical wave fusion communication device, and the optical / electrical / electrical / optical conversion unit 10 (“photoelectric conversion” on the wireless device side in the station building as the wireless device side equipment. And an optical / electrical / electrical / optical conversion unit 20 (denoted as “photoelectric conversion unit 20”) on the antenna side at the top of the steel tower as the antenna-side equipment.

  In FIG. 1, the code | symbol 1 represents the radio | wireless apparatus in a station building, and the code | symbol 3 represents the antenna attached to the steel tower.

  As a specific example of the radio apparatus 1, for example, a microwave radio apparatus used for a fixed service radio station for public / telecommunications business or the like can be cited.

  As the antenna 3, an antenna (specifically, for example, a parabolic antenna) that has been used in conventional wireless communication can be used. Specifically, an electric wave that receives a radio wave and corresponds to the electric field strength of the radio wave is used. It is not limited to a specific one as long as it outputs a signal and transmits a radio wave having an electric field intensity corresponding to the input electric signal.

  The photoelectric conversion unit 10 on the wireless device side is attached to the waveguide portion for high-frequency input / output of the wireless device 1 in the office building, and the photoelectric conversion unit 20 on the antenna side is attached to the waveguide connection port of the antenna 3. These are connected by a multi-core optical fiber cable.

  In the communication system shown in FIG. 1, for example, it is not necessary to modify the existing microwave radio main body and the parabolic antenna, and a mode in which only the waveguide portion is replaced is used. The main invasion path of lightning surge current that penetrates into the inside of the station building (in other words, flows in) by replacing the waveguide between the station side facility and the antenna side facility of the microwave radio equipment with an optical fiber. One of them is removed, and a great effect is expected in protecting the device.

  Microwave wireless communication uses two sets of links of optical radio waves in opposite directions to perform full-duplex communication of transmission and reception by frequency division bidirectional transmission (also expressed as “FDD”). In order to share the antenna 3 with a transceiver, an antenna duplexer 26 composed of bandpass filters 22 and 24 and a circulator 23 is used.

  And the photoelectric conversion part 10 by the side of the radio | wireless apparatus in a station building receives the electrical signal as a transmission signal output from the radio | wireless apparatus 1 as a mechanism which sends a transmission signal from the radio | wireless apparatus 1 to the antenna 3. A circulator 11 that outputs the electric signal to the electric / optical converter 12, and an electric signal as a transmission signal output from the circulator 11 is input and the electric signal is converted into an optical signal to convert the electric signal on the antenna side. The electrical / optical conversion part 12 radiate | emitted to the conversion part 20 is provided.

  An optical signal as a transmission signal emitted from the electrical / optical conversion unit 12 of the photoelectric conversion unit 10 on the wireless device side in the office building is transmitted to the photoelectric conversion unit 20 on the antenna side above the steel tower through the optical fiber 2A. The

  The photoelectric conversion unit 10 on the wireless device side also transmits a reception signal from the antenna 3 to the wireless device 1 as a reception signal emitted from the photoelectric conversion unit 20 on the antenna side and transmitted by the optical fiber 2C. An optical / electrical conversion unit 13 that receives an optical signal and converts the optical signal into an electrical signal and outputs the electrical signal to the circulator 11 is provided.

  The circulator 11 outputs an electrical signal as a received signal output from the optical / electrical converter 13 and input to the wireless device 1.

  The photoelectric conversion unit 10 on the wireless device side further includes a power supply unit 15 that supplies power to the electrical / optical conversion unit 12, the optical / electrical conversion unit 13, and the optical power transmission / transmission unit 16, and power from the power supply unit 15. An optical power feeding transmission unit 16 that is supplied and emits light (high power light for power feeding) to the photoelectric conversion unit 20 on the antenna side is provided.

  High-power light for power feeding emitted from the optical power feeding / transmitting unit 16 of the photoelectric conversion unit 10 on the radio device side in the station building is transmitted to the photoelectric conversion unit 20 on the antenna side above the tower by the optical fibers 2B and 2D. Is done.

  One or a plurality of power supply units 15 for supplying power to the electrical / optical conversion unit 12, the optical / electrical conversion unit 13, and the optical power feeding / transmission unit 16 may be used, and light is emitted to the photoelectric conversion unit 20 on the antenna side. One or a plurality of optical power feeding / transmitting units 16 may be provided.

  In addition, the photoelectric conversion unit 20 on the antenna side on the tower is configured to send a transmission signal from the wireless device 1 to the antenna 3. Specifically, in the example shown in FIG. 1, the photoelectric conversion unit 10 on the wireless device side The optical / electrical conversion unit 12) and the optical fiber 2A connected to each other and an optical signal as a transmission signal transmitted by the optical fiber 2A is incident, and the optical signal is converted into an electrical signal and output. Only a predetermined electrical signal (specifically, an electrical signal in a frequency band used in wireless communication) of the electrical signal as a transmission signal output from the unit 21 and the optical / electrical conversion unit 21 is allowed to pass. A bandpass filter 22 and a circular circuit that receives an electric signal as a transmission signal output from the bandpass filter 22 and outputs the electric signal to the antenna 3. And a 23.

  The circulator 23 also receives an electric signal as a reception signal output from the antenna 3 and outputs the electric signal to the band pass filter 24.

  The antenna 3 transmits a radio wave having an electric field strength corresponding to an electric signal as a transmission signal output from the circulator 23 and input.

  The photoelectric conversion unit 20 on the antenna side is a mechanism for sending a reception signal from the antenna 3 to the wireless device 1, and a predetermined electric signal (specifically, an electric signal as a reception signal output from the circulator 23). Is a band-pass filter 24 that passes only an electric signal in a frequency band used in wireless communication, and an electric signal as a reception signal output from the band-pass filter 24 is input and the electric signal is converted into an optical signal. An electric / optical conversion unit 25 that converts the light into a light and emits the light is provided.

  An optical signal as a reception signal emitted from the electrical / optical conversion unit 25 of the photoelectric conversion unit 20 on the antenna side on the tower top is transmitted to the photoelectric conversion unit 10 on the wireless device side in the office via the optical fiber 2C. The

  The photoelectric conversion unit 20 on the antenna side is further connected to the optical power transmission / transmission unit 16 via the optical fibers 2B and 2D, and receives light (high output light for power supply) emitted from the optical power transmission / transmission unit 16 to generate electric power. An optical power receiving unit 27 that converts the power and supplies the electric power to the optical / electrical converter 21 and the electrical / optical converter 25 is provided.

  The electrical / optical conversion unit 25 is connected to the photoelectric conversion unit 10 (specifically, the optical / electrical conversion unit 13 in the example shown in FIG. 1) and the optical fiber 2C.

  The number of the optical power feeding receiving units 27 that are part of the mechanism for supplying the power of the power source unit 15 of the photoelectric conversion unit 10 on the wireless device side to the photoelectric conversion unit 20 on the antenna side may be one or more. The optical fibers 2B and 2D that connect the optical power transmission / reception unit 16 of the photoelectric conversion unit 10 on the wireless device side and the optical power reception unit 27 of the photoelectric conversion unit 20 on the antenna side are configured by a single optical fiber cable. Alternatively, it may be configured by a plurality of optical fiber cables.

  Here, as an example of the communication system / device as described above, for example, a technique described in Japanese Patent Application Laid-Open No. 2015-27020 can be cited.

  The electrical / optical converters 12 and 25 convert electrical signals into optical signals. Specifically, the electrical / optical converters 12 and 25 convert the intensity of incident light (that is, input light; also referred to as an optical carrier wave) into input electrical power. The light is modulated according to the electric field strength of the signal and emitted as a light modulation wave. The electrical / optical converters 12 and 25 include a semiconductor laser light source, for example.

  The optical / electrical converters 13 and 21 convert an optical signal into an electrical signal. Specifically, for example, a photodiode can be used.

  If necessary, the photoelectric conversion unit 10 on the wireless device side amplifies the light intensity of the optical signal emitted from the electrical / optical conversion unit 12 and emits the light from the photoelectric conversion unit 20 on the antenna side. An optical amplifier that amplifies and emits the light intensity of the optical signal transmitted by the optical fiber 2C may be further provided. An optical amplifier has a specific mechanism or object as long as it is capable of amplifying incident light (in other words, it has a gain in the wavelength band of light used and can be used as an amplifier). It is not limited.

  The photoelectric conversion unit 20 on the antenna side is output from a high-frequency amplifier that amplifies and outputs a transmission output of an electrical signal as a transmission signal output from the optical / electrical conversion unit 21 or a band pass filter 24 as necessary. You may make it further provide the high frequency amplifier which amplifies and outputs the received output of the electrical signal as a received signal. When the antenna-side photoelectric conversion unit 20 includes a high-frequency amplifier, the power converted by the optical power feeding / receiving unit 27 is also supplied to the high-frequency amplifier as driving power (in other words, the high-frequency amplifier). The driving power of the amplifier is supplied by optical fiber feeding).

  The high-frequency amplifier is provided between the optical / electrical converter 21 and the bandpass filter 22 and between the bandpass filter 24 and the electrical / optical converter 25.

  And, for example, in a communication system / device as shown in FIG. 1, even when a lightning strike to the antenna 3 occurs, a good lightning resistance performance is ensured so that the photoelectric conversion unit 20 on the antenna side operates without failure. For this reason, in this embodiment, the photoelectric conversion unit 20 on the antenna side in the upper part of the tower as the antenna side equipment installed in the tower 4 and the radio apparatus side in the station as the radio apparatus side equipment installed outside the tower 4 The communication device configured to include the photoelectric conversion unit 10, between the module 21 and the like constituting the antenna-side photoelectric conversion unit 20 and the housing 30 that stores the module 21 and the like and is installed on the tower 4. A member having electrical insulation performance (reference numeral 32 in FIG. 3, reference numeral 33 in FIG. 4, reference numeral 31i in FIG. 5) is interposed.

  In the present embodiment, the photoelectric conversion unit 20 on the antenna side at the top of the tower as the antenna side equipment installed on the tower 4 and the radio apparatus side in the station as the radio apparatus side equipment installed outside the tower 4 are also shown. The communication device configured to include the photoelectric conversion unit 10 stores the module 21 constituting the photoelectric conversion unit 20 on the antenna side and is electrically insulated between the casing 30 and the tower 4 installed on the tower 4. Members having performance (reference numerals 6 and 4b in FIG. 6) are interposed.

  Since the optical fibers 2A to 2D connecting the photoelectric conversion unit 20 on the antenna side of the tower and the photoelectric conversion unit 10 on the wireless device side in the office are insulators, the optical fibers 2A to 2D are lightning surge currents. There is no intrusion route.

  On the other hand, the antenna 3 and the photoelectric conversion unit 20 on the antenna side need to be connected by a short waveguide or a coaxial cable, and each of them includes the optical / electrical conversion unit 21 and the electrical / optical conversion unit 25. The housing for storing the module needs to be fixed to the steel tower. In addition, when the antenna mount 3a is provided on the back surface of the antenna 3 and the antenna mount 3a is directly fixed to the steel tower 4, the antenna 3 can be connected to the steel tower 4 in a state where the antenna 3 and the steel tower 4 can be electrically connected. It is attached to.

In the case of such a configuration / structure, according to the knowledge of the inventor, when a direct lightning strike 9 occurs on the antenna 3, the following two paths become the main paths of surge current (FIG. 2).
<Route i> Antenna 3 → Antenna mount 3a → Tower base 4a of tower 4 → Ground <Path ii> Antenna 3 → Antenna mount 3a → Waveguide / coaxial cable 5 → Photoelectric conversion unit 20 on the antenna side → Tower 4 tower Leg 4a → Earth

  2 to 6 are conceptual diagrams for explaining the outline of the device configuration / facility configuration related to the antenna-side equipment and the steel tower, to which the lightning protection performance improving method according to the present invention can be applied. It does not prescribe a dimensional relationship between members or a specific detailed structure.

(2) Electrical insulation between the module and the housing Prevents lightning surge current from flowing into the module inside the housing that houses the various equipment and devices that make up the antenna-side equipment (in other words, inflow) In order to sufficiently reduce the lightning surge current (the shunt current) that passes through each module, it is possible to realize a configuration that does not create a path through which the lightning surge current flows. Each module and the housing are electrically insulated so as not to be directly electrically connected to the body (see FIGS. 3 to 5).

  The casing 30 is installed on the upper part of the steel tower 4 to which the antenna 3 is attached, in order to store the antenna-side equipment (in other words, to store each module constituting the antenna-side equipment).

  In the present embodiment, the housing 30 stores the photoelectric conversion unit 20 on the antenna side as the antenna-side equipment. Therefore, as a module stored in the housing 30, specifically, for example, the optical / electrical conversion unit 21, the band pass filters 22 and 24, the circulator 23, the electric / optical conversion unit 25, the optical power feeding reception unit 27, and the like. (Denoted as “module 21 etc.”).

  The electrical insulation between the module 21 and the like and the case 30 (in other words, the case main body and the case itself) is performed so that the module 21 and the case 30 are not electrically connected directly. This is realized by interposing a member having an electrical insulation performance formed of an insulating material and an insulator between 21 and the like and the housing 30.

  The insulating material and insulator for forming a member interposed between the module 21 and the housing 30 are not limited to a specific type, and for example, durability and robustness may be ensured. An appropriate material is appropriately selected after being considered.

  The aspect of the member having the electrical insulation performance interposed between the module 21 and the housing 30 is such that the module 21 and the housing 30 are directly and electrically interposed between the module 21 and the housing 30. It is not limited to a specific mode as long as it can prevent connection and realize electrical insulation between them. For example, the structure of the housing (particularly the internal structure), the module 21, etc. In consideration of the above-mentioned form, an appropriate mode is appropriately selected.

  Specifically, as an aspect of a member having electrical insulation performance interposed between the module 21 or the like and the housing 30, for example, as an example only, the module 21 and the like are disposed inside the housing 30 and the like. A mat-like member (specifically, for example, a rubber-made member) is mounted between a module mounting plate 31 that functions as a module that is mounted and fixes the module 21 and the like in the housing 30 and a member constituting the housing 30 itself. It is conceivable that the mat 32) is sandwiched (FIG. 3). That is, the member having electrical insulation performance in the present invention may be formed in a mat shape and sandwiched between the module mounting plate 31 to which the module 21 or the like is mounted and the housing 30.

  As an aspect of a member having electrical insulation performance that is interposed between the module 21 and the like and the housing 30, or as an electrically insulating spacer between the module mounting plate 31 and a member constituting the housing 30 itself. In this case, a space is provided between the module mounting plate 31 and the members constituting the housing 30 itself. That is, the member having electrical insulation performance in the present invention is formed as the electrical insulation spacer 33 and is partially installed between the module attachment plate 31 to which the module 21 and the like are attached and the housing 30, and these module attachment plates 31. A space may be provided between the housing 30 and the housing 30.

  In the example shown in FIG. 4, the number of electrically insulating spacers 33 that are sandwiched between the module mounting plate 31 and the housing 30 is four, but the number of electrically insulating spacers 33 is However, the number is not limited to four, and the number is not limited to a specific number as long as the number is one or more (within a practical range where installation is possible). Moreover, in the example shown in FIG. 4, each electric insulation spacer 33 is formed in a columnar shape (in other words, a drum shape, a drum shape), but the form of the electric insulation spacer 33 is limited to a columnar shape. For example, a prismatic shape may be used. That is, the number and form of the electrically insulating spacers 33 can be used as long as the module mounting plate 31 can be fixed to the housing 30 and a space can be formed between the housing 30 and the module mounting plate 31. Any number and any form may be used.

  As an aspect of a member having electrical insulation performance interposed between the module 21 and the housing 30 or the module mounting plate itself is formed as a plate-like member (specifically, for example, a resin plate 31i). It is conceivable to do this (FIG. 5). That is, the member having electrical insulation performance in the present invention may be formed in a plate shape as the module mounting plate 31i to which the module 21 or the like is mounted.

  Note that when the module 21 and the like and the housing 30 storing the module 21 and the like are electrically insulated, when a direct lightning strike 9 occurs on the antenna 3, <path ii> in FIG. Is cut off and removed, and <path i> becomes a path of surge current.

(3) Electrical insulation between the housing and the tower Prevents lightning surge current from flowing into the housing that houses the various equipment and devices that make up the antenna-side equipment (in other words, incoming lightning surge) In order to sufficiently reduce the current (the shunt current)), the casing and the steel tower on which the casing is installed can be realized so that a configuration in which a lightning surge current does not flow through the casing itself can be realized. Electrical insulation is performed between the housing and the tower without being directly electrically connected (see FIG. 6).

  The electrical insulation between the casing 30 (in other words, the casing body, the casing itself) and the tower 4 (in other words, the members constituting the tower 4) is performed between the casing 30 and the tower 4. It implement | achieves by interposing the member provided with the electrical insulation performance formed of the insulating material and the insulator between these housing | casing 30 and the steel tower 4 so that it may not electrically connect directly.

  The insulating material and insulator for forming a member interposed between the housing 30 and the steel tower 4 are not limited to a specific type, and for example, it is considered that durability and robustness are ensured. Then, an appropriate material is appropriately selected.

  The aspect of the member having the electrical insulation performance interposed between the housing 30 and the steel tower 4 is that the housing 30 and the steel tower 4 are electrically connected directly between the housing 30 and the steel tower 4. Is not limited to a specific mode as long as electrical insulation can be realized between them, for example, a housing structure (especially an external structure) or a steel tower structure (especially, In consideration of the structure of the part to which the housing 30 is fixed and the form of the member), an appropriate mode is appropriately selected.

  Specifically, as an aspect of a member having electrical insulation performance interposed between the housing 30 and the steel tower 4, for example, the housing 30 is a constituent member of the steel tower 4 (example shown in FIG. 6). Then, it is conceivable to use a resin-made fixture (in other words, a gripping tool; a member denoted by reference numeral 6 in the example shown in FIG. 6) for attachment to the pole 4b for housing attachment. That is, the member having electrical insulation performance in the present invention may be formed as an attachment / gripping tool 6 for attaching the housing 30 to the steel tower 4.

  As an aspect of the member having electrical insulation performance interposed between the casing 30 and the steel tower 4, or a portion of the steel tower 4 to which the casing 30 is attached (the housing mounting pole in the example shown in FIG. 6). It is conceivable that 4b) is formed of a resin member. That is, the member having electrical insulation performance in the present invention is formed as a housing support member (a housing mounting pole 4b in the example shown in FIG. 6) that is provided in the steel tower 4 and to which the housing 30 is attached. May be.

  Therefore, in the example shown in FIG. 6, it is conceivable that at least one of the housing mounting pole 4b and the mounting tool / gripping tool 6 is formed of a member having electrical insulation performance.

  If the casing 30 and the steel tower 4 are electrically insulated, when a direct lightning strike 9 occurs on the antenna 3, <path ii> in FIG. 2 is blocked and removed, and < The path i> is a surge current path (see also FIG. 6).

  According to the lightning resistance improvement method configured as described above, a member (specifically, a member having electrical insulation performance on the path from the tower 4a to the ground via the module 21 and the like from the antenna 3 to the ground) For example, as shown in FIGS. 3 to 6, a rubber mat 32, an electrically insulating spacer 33, a resin plate 31i, a fixture / gripping tool 6, or a housing mounting pole 4b) are provided. Therefore, even if a direct lightning strike 9 occurs on the antenna 3, it is possible to prevent the surge current from entering / inflowing into the module 21 or the like. For this reason, it is possible to improve the lightning resistance performance of the photoelectric conversion unit 20 on the antenna side as the antenna-side equipment, and thus it is possible to improve the stability and reliability as the communication device.

  Although the above-described embodiment is an example of a preferred embodiment for carrying out the present invention, the embodiment of the present invention is not limited to the above-described embodiment, and the present invention is not limited to the scope of the present invention. The invention can be variously modified.

  For example, in the above-described embodiment, the present invention is applied to the facility configuration exemplified in FIG. 7 and the communication system / device exemplified in FIG. 1, but the facility to which the present invention can be applied. The configuration and the system configuration / device configuration are not limited to those in the above-described embodiment, but a communication device configured to have an antenna-side facility installed on the tower and a radio-device-side facility installed outside the tower. Can be widely applied in general.

  In the above-described embodiment, members (32, 33, 31i) having electrical insulation performance are interposed between the module 21 and the like and the housing 30, and electrical insulation performance is provided between the housing 30 and the steel tower 4. The members (6, 4b) provided are interposed, but members having electrical insulation performance are interposed both between the module 21 and the case 30 and between the case 30 and the steel tower 4. This is not an essential configuration in the present invention, and a member having electrical insulation performance is interposed between at least one of the module 21 and the like and the case 30 and between the case 30 and the steel tower 4. Also good. Only one of them can reduce the lightning surge current flowing into the module 21 or the like.

DESCRIPTION OF SYMBOLS 1 Radio | wireless apparatus 2A Optical fiber 2B Optical fiber 2C Optical fiber 2D Optical fiber 3 Antenna 3a Antenna mount 4 Steel tower 4a Tower leg 4b Case mounting pole 5 Waveguide, coaxial cable 6 Fixing / gripping tool 9 Direct strike lightning 10 Radio Optical / electrical / electrical / optical conversion unit on the device side, photoelectric conversion unit 11 on the wireless device side, circulator 12, electrical / optical conversion unit 13, optical / electrical conversion unit 15 power supply unit 16, optical power transmission / transmission unit 20 optical / electrical / electrical unit on the antenna side Electric / optical conversion unit, photoelectric conversion unit 21 on the antenna side optical / electrical conversion unit 22 band pass filter 23 circulator 24 band pass filter 25 electric / optical conversion unit 26 antenna duplexer 27 optical power receiving unit 30 housing 31 module mounting plate 31i Module mounting plate (resin plate) with electrical insulation performance
32 Mat 33 Electric insulating spacer

Claims (7)

  A communication device configured to have an antenna-side facility installed on a steel tower and a radio-device-side equipment installed outside the tower, stores the module constituting the antenna-side facility and the module, and stores the module in the tower A method for improving lightning resistance, characterized in that a member having electrical insulation performance is interposed between a housing to be installed.   The method for improving lightning resistance according to claim 1, wherein the member having electrical insulation performance is formed in a mat shape and is sandwiched between a module mounting plate to which the module is mounted and the housing.   The lightning-proof performance according to claim 1, wherein the member having electrical insulation performance is formed as an electrical insulation spacer and is partially installed between a module mounting plate to which the module is attached and the housing. How to improve.   The method for improving lightning resistance according to claim 1, wherein the member having electrical insulation performance is formed in a plate shape as a module mounting plate to which the module is mounted.   A communication device configured to have an antenna-side facility installed on a steel tower and a radio device-side equipment installed outside the steel tower, housing a module constituting the antenna-side equipment and installed on the steel tower A method for improving lightning resistance, wherein a member having electrical insulation performance is interposed between a body and the steel tower.   The method for improving lightning resistance according to claim 5, wherein the member having the electrical insulation performance is formed as a fixture for attaching the casing to the steel tower.   The method for improving lightning resistance according to claim 5, wherein the member having electrical insulation performance is formed as a housing support member that is provided on the tower and to which the housing is attached.