Intelligent monitoring device based on outdoor disconnecting switch and networking system

Abstract

The utility model provides an intelligent monitoring device based on an outdoor disconnecting switch and a networking system, a moving contact and a static contact of an outdoor disconnecting switch body of the intelligent monitoring device are connected with a wire inlet busbar and a wire outlet busbar, the moving contact is connected with a rotating mechanism through a control rod, and the rotating mechanism is directly connected with an operating mechanism box through an operating rod. The operating mechanism box internally comprises a main shaft and a motor installed on the main shaft, the monitoring assembly comprises an isolating switch acquisition module and an operating mechanism box acquisition module which are installed in the outdoor isolating switch body and the operating mechanism box respectively, and the intelligent monitoring unit is electrically connected with the monitoring assembly. The intelligent monitoring unit correspondingly processes data collected by the monitoring assembly and then communicates with the display end through a Modbus, and the display end can check relevant information on site. The intelligent monitoring device monitors the action condition of the main contact of the disconnecting switch in real time, judges whether the connecting rod of the disconnecting switch mechanism is abnormal or not and whether the auxiliary contact is reliable and in place or not, and realizes accurate maintenance.

Description

Technical Field

[0001] The utility model relates to the technical field of disconnectors, and particularly relates to an intelligent monitoring device and system based on an outdoor disconnector. Background Art

[0002] Outdoor catenary disconnectors are mainly used in the DC traction power supply system of rail transit. They adopt a hanging structure and are installed on tunnels or catenary brackets. The disconnector adopts a split structure and is composed of three major parts: the disconnector body, the operating connecting rod, and the operating mechanism box. The disconnector is used to connect the DC fast circuit breaker of the DC switch cabinet with the catenary or contact rail, and can provide an effective path for DC traction power supply under no-load conditions or can provide an obvious isolation break point during equipment maintenance. The following are the main problems in the current user operation and maintenance process:

[0003] a) The mechanism failure cannot be effectively monitored

[0004] The mechanism failure includes abnormal contact resistance of the catenary disconnector, abnormal damage of the insulator of the disconnector body, abnormal fracture of the operating connecting rod, caused by the failure of the electric operating mechanism, and the auxiliary contact cannot be reliably in place. The disadvantages of traditional manual maintenance methods: After each failure or once a year for regular inspection, professional testing equipment needs to be carried, and the maintenance has no predictability; affected by human factors or restricted by maintenance means, there is a situation of missed inspection.

[0005] b) The health status of the disconnector motor cannot be evaluated

[0006] Currently, only after the motor fails, manual inspection or inspection based on professional instruments is carried out, and there are also human factor influences or maintenance means restrictions;

[0007] c) The change of the contact resistance between the moving and static contacts of the disconnector cannot be effectively monitored

[0008] Due to the limitations of manpower and time, this detection is an annual single planned maintenance, which may not cover the change of the contact resistance of the disconnector contacts throughout the year, and there is a possibility of missed inspection.

[0009] d) The temperature and humidity inside the disconnector operation box cannot be monitored in real time online and an early warning for abnormal situations cannot be given

[0010] Excessive humidity inside the disconnector operation box is likely to cause failures of electronic components inside the operation box;

[0011] e) The opening and closing states of the disconnector cannot be effectively identified;

[0012] f) The electrical interlock circuit is complex and the construction is cumbersome;

[0013] The electrical interlock of the disconnector is usually implemented by hard wiring. The interlock involves this substation and adjacent substations. The disadvantages of using hard wiring interlock are as follows: the interlock circuit is complex, the construction is cumbersome, and it is easy to make mistakes when connecting the circuit, which may cause circuit failures; the long line of the interlock control cable is vulnerable to interference, and the interlock control cable is prone to breakage and other abnormal conditions, increasing the cost of the interlock control cable in the initial stage of construction. Summary of the Invention

[0014] Object of the Invention: In order to overcome the deficiencies of the above-mentioned prior art, the present application provides an intelligent monitoring device based on an outdoor disconnector, which solves the problems existing in the background technology.

[0015] Technical Solution: The present utility model provides an intelligent monitoring device based on an outdoor disconnector, which includes an outdoor disconnector body, a monitoring component, an intelligent monitoring unit, a display terminal and an operating mechanism box. The outdoor disconnector body includes a moving contact and a static contact. An incoming line busbar and an outgoing line busbar are connected to the moving contact and the static contact. The moving contact is connected to a rotating mechanism through a control rod, and the rotating mechanism is directly connected to the operating mechanism box through an operating rod. The operating mechanism box includes a main shaft and a motor arranged circumferentially on the main shaft. The monitoring component includes a disconnector monitoring module and an operating mechanism box monitoring module, which are respectively installed in the outdoor disconnector body and the operating mechanism box. The intelligent monitoring unit is electrically connected to the monitoring component and is placed in the operating mechanism box. After the intelligent monitoring unit processes the data collected by the monitoring component correspondingly, it sends the data to the display terminal. Specifically:

[0016] The disconnector monitoring module includes a first temperature sensor, a second temperature sensor, a third temperature sensor and a fourth temperature sensor. The operating mechanism box monitoring module includes an angular displacement sensor, a first current sensor and a second current sensor. The first temperature sensor is installed on the incoming line busbar, the second temperature sensor is arranged on the outgoing line busbar, the third temperature sensor is arranged on the moving contact, and the fourth temperature sensor is installed on the static contact. The first temperature sensor, the second temperature sensor, the third temperature sensor and the fourth temperature sensor respectively collect the real-time temperatures of the incoming line busbar, the outgoing line busbar, the moving contact and the static contact, and send the relevant temperature data to the intelligent monitoring unit;

[0017] The angular displacement sensor is installed on the main shaft, and is used for measuring the angular displacement value of the main shaft in real time and uploading it to the intelligent monitoring unit. The intelligent monitoring unit judges and alarms abnormal values according to the real-time angular displacement value, and records the angular displacement signal;

[0018] The first current sensor is installed in the circuit loop formed by closing the motor, and the second current sensor is installed in the circuit loop formed by opening the motor. They respectively monitor the closing current and opening current of the disconnector motor in real time, and transmit the obtained analog current data signals to the intelligent monitoring unit in real time.

[0019] Furthermore, it includes:

[0020] The operating mechanism box monitoring module further includes a temperature and humidity sensor. The temperature and humidity sensor is arranged inside the operating mechanism box, and it is used to monitor the temperature and humidity inside the operating mechanism box and transmit them to the intelligent monitoring unit in real time through RS485.

[0021] Furthermore, it includes:

[0022] The device further includes a camera, which is arranged outside the outdoor disconnector body and its installation position is not lower than the highest point of the outdoor disconnector body, and is used to monitor the states of the moving contact of the disconnector and various components in real time.

[0023] Furthermore, it includes:

[0024] The temperature and humidity sensor is connected to the intelligent monitoring unit through an RS485 communication interface.

[0025] Furthermore, it includes:

[0026] The first temperature sensor, the second temperature sensor, the third temperature sensor and the fourth temperature sensor are all connected to the intelligent monitoring unit in a wireless transmission manner.

[0027] Furthermore, it includes:

[0028] The intelligent monitoring unit is a single-chip microcomputer.

[0029] On the other hand, the present invention also provides an intelligent monitoring networking system based on an outdoor disconnector, including the above-mentioned intelligent monitoring unit based on an outdoor disconnector, a first switch, a first optical fiber pigtail box and a substation integrated automation system. The intelligent monitoring device is connected to the first switch through an Ethernet cable, the first switch is connected to the first optical fiber pigtail box through an optical fiber, and the first optical fiber pigtail box is connected to the substation integrated automation system through an optical fiber.

[0030] Furthermore, it includes:

[0031] The substation integrated automation system includes a second switch, a second fiber optic pigtail box, and a communication controller. The first fiber optic pigtail box is interconnected with the second fiber optic pigtail box through an optical fiber. The second fiber optic pigtail box is connected to the second switch through an optical fiber. The second switch is connected to the communication controller through an Ethernet connection.

[0032] Beneficial effects: Compared with the prior art, the present utility model has the following advantages:

[0033] The present utility model can monitor the action of the main contact of the disconnector in real time, judge whether the connecting rod of the disconnector mechanism is abnormal, and whether the auxiliary contact is in place reliably, so as to achieve precise maintenance;

[0034] The present utility model can monitor the working conditions of the disconnector motor in real time, predict potential faults, identify early faults of equipment, give maintenance suggestions, avoid passive maintenance after faults, and ensure safe operation;

[0035] The present utility model can accurately analyze the temperature and humidity changes in the operation box, avoid the oxidation of the metal parts of the electronic components caused by excessive humidity, which may lead to unstable or ineffective operation of the electronic components, and avoid the short circuit or leakage of the electrical components caused by the damage of the insulation layer. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 It is a schematic structural diagram of the intelligent monitoring device described in the present utility model;

[0038] Figure 2 It is a schematic structural diagram of the installation position of the camera described in the present utility model;

[0039] Figure 3 It is a schematic connection diagram of the monitoring component and the intelligent monitoring unit described in the present utility model;

[0040] Figure 4 It is a schematic structural diagram of the intelligent monitoring networking system described in the present utility model;

[0041] The figure includes: outdoor disconnector body 1, incoming busbar 11, outgoing busbar 12, control rod 30, operating connecting rod 14, rotating mechanism 31, monitoring component 2, first temperature sensor 21, second temperature sensor 22, third temperature sensor 23, fourth temperature sensor 24, angular displacement sensor 25, first current sensor 26, second current sensor 27, temperature and humidity sensor 28, intelligent monitoring unit 3, display end 4, operating mechanism box 5, main shaft 51, camera 6, intelligent monitoring device 100, first switch 200, first optical fiber pigtail box 300, substation integrated automation system 400, second switch 401, second optical fiber pigtail box 402, communication controller 403. Detailed implementation

[0042] In order to enable those skilled in the art of this technology to better understand the solution of this application, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0043] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so as to describe the embodiments of this application here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0044] In this application, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe this application and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation.

[0045] Moreover, in addition to being used to indicate orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to the specific circumstances.

[0046] In addition, the terms "install", "set", "provided with", "connect", "connected", "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there is internal communication between two devices, components or parts. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0047] It should be noted that, without conflict, the embodiments and features in the embodiments of this application can be combined with each other. The following will detail this application with reference to the drawings and in combination with the embodiments.

[0048] Embodiment 1

[0049] On one hand of the present utility model, as Figure 1 shown, a smart monitoring device based on an outdoor disconnect switch is provided, which includes an outdoor disconnect switch body 1, a monitoring component 2, a smart monitoring unit 3, a display end 4 and an operating mechanism box 5. The outdoor disconnect switch body 1 includes a moving contact and a static contact. An incoming line busbar 11 and an outgoing line busbar 12 are connected to the moving contact and the static contact. The moving contact is connected to a rotating mechanism 31 through a control rod 30. The rotating mechanism 31 is directly connected to the operating mechanism box 5 through an operating rod 14. The operating mechanism box 5 includes a main shaft 51 and a motor 52 arranged circumferentially on the main shaft 51. The monitoring component 2 includes a disconnect switch acquisition module and an operating mechanism box acquisition module, which are respectively installed in the outdoor disconnect switch body 1 and the operating mechanism box 5. The smart monitoring unit 3 is electrically connected to the monitoring component 2 and is placed in the operating mechanism box 5. After the smart monitoring unit 3 processes the data collected by the monitoring component 2 correspondingly, it is sent to the display end 4. In this embodiment, the smart monitoring unit 3 can be a processor such as a single-chip microcomputer, and the display end 4 is an electronic device with a display screen such as a computer, a mobile phone, or a PAD.

[0050] Specifically:

[0051] The disconnect switch monitoring module includes a first temperature sensor 21, a second temperature sensor 22, a third temperature sensor 23 and a fourth temperature sensor (attached Figure 1(not shown in the figure), the operating mechanism box monitoring module includes an angular displacement sensor 25, a first current sensor 26, and a second current sensor 27. The first temperature sensor 21 is installed on the incoming line busbar 11, the second temperature sensor 22 is arranged on the outgoing line busbar 12, the third temperature sensor 23 is arranged on the moving contact, and the fourth temperature sensor 24 is installed on the static contact. The first temperature sensor 21, the second temperature sensor 22, the third temperature sensor 23, and the fourth temperature sensor 24 respectively collect the real-time temperatures of the incoming line busbar 11, the outgoing line busbar 12, the moving contact, and the static contact, and send the relevant temperature data to the intelligent monitoring unit 3. The first temperature sensor 21, the second temperature sensor 22, the third temperature sensor 23, and the fourth temperature sensor 24 are all connected to the intelligent monitoring unit 3 by means of wireless transmission.

[0052] Wireless temperature sensors are installed at the moving and static contacts of the disconnector and at the incoming and outgoing line busbars, which can real-time monitor the temperature values of the moving and static contacts of the disconnector and the incoming and outgoing busbars. The detected data is uploaded to the intelligent monitoring unit 3 through wireless transmission. The intelligent monitoring unit 3 reads and receives the data through RS485 or serial communication, etc., and real-time detects the current temperature of the measured part. When the measured data exceeds the set value, an alarm is given. The real-time temperature values and alarm signals of the moving and static contacts of the disconnector and the incoming and outgoing busbars are forwarded and uploaded through the MMS protocol.

[0053] The angular displacement sensor 25 is installed on the main shaft 51, which is used to measure the angular displacement value of the main shaft 51 in real time and upload it to the intelligent monitoring unit 3. The intelligent monitoring unit 3 gives an alarm for abnormal values according to the measured value and records and analyzes the angular displacement signal; after the intelligent monitoring unit 3 records and analyzes the angular displacement signal, it uploads the real-time angular displacement value and alarm signal of the main shaft of the disconnector operating mechanism through the MMS protocol. Therefore, it realizes real-time monitoring of the action of the main contact of the disconnector, judges whether the connecting rod of the disconnector mechanism is abnormal, and whether the auxiliary contact is in place reliably, so as to carry out precise maintenance.

[0054] Furthermore, in this embodiment, the first current sensor 26 is installed in the circuit loop formed by the motor closing, and the second current sensor 27 is installed in the circuit loop formed by the motor opening, which respectively monitor the closing current and opening current of the disconnector motor in real time, and send the obtained current data to the intelligent monitoring unit 3 in real time.

[0055] In the opening and closing circuits of the disconnector motor, current sensors are used to monitor the opening current and closing current of the disconnector motor in real time, and then transmit them to the intelligent monitoring unit 3 to form corresponding waveforms, support state-triggered wave recording, with a wave recording duration of not less than 10 s, and conduct wave recording analysis to obtain the peak value of the motor starting current, the peak and average values of the current during the opening and closing processes, the starting time of the motor, the maximum torque time, the opening and closing time of the motor, the current cut-off time, and evaluate the health status of the motor by comparing with the standard curve library. The analysis results are connected to the superior platform through the MMS protocol. Therefore, the utility model can monitor the working conditions of the disconnector motor in real time, predict potential faults, identify early faults of equipment, give maintenance suggestions, avoid passive maintenance after faults, and ensure safe operation.

[0056] Further, in this embodiment, the operating mechanism box monitoring module further includes a temperature and humidity sensor 28, which is arranged in the operating mechanism box 5 and is used to monitor the temperature and humidity in the operating mechanism box 5, and transmits them to the intelligent monitoring unit 3 in real time. The intelligent monitoring unit 3 forwards and uploads the temperature and humidity values in the operating box through the MMS protocol.

[0057] The intelligent monitoring unit 3 can accurately analyze the changes in temperature and humidity in the operating box, alarm for abnormal values, and timely start the anti-condensation device to avoid the oxidation of metal parts of electronic components caused by excessive humidity, resulting in unstable or ineffective operation of electronic components, and short circuits or electric leaks caused by damage to the insulation layer.

[0058] Further, in this embodiment, as Figure 2 shown, the intelligent monitoring device further includes a camera 6, which is arranged outside the outdoor disconnector body 1 and its installation position is preferably not lower than the highest point of the outdoor disconnector body 1, and is used to monitor the states of the moving contact and various components of the disconnector in real time.

[0059] The intelligent monitoring unit 3 supports accessing the video data of the camera through the Ethernet port, parsing the camera video data packet, performing intelligent recognition on the video data, comparing the video data with the switch state, and evaluating the health status of the disconnector contact. The real-time video of the disconnector opening and closing process and the intelligent recognition results are forwarded and uploaded through the MMS protocol. Therefore, this embodiment makes a secondary judgment and recognition on the abnormal switch position state, and the switch position state is accurate and reliable.

[0060] Moreover, further, in this embodiment, the operation locking of the disconnector body is replaced by the GOOSE network signal of the intelligent monitoring unit 3 instead of the hard-wired locking communication method between various devices in the conventional substation, which greatly simplifies the secondary cable wiring between various devices in this substation and adjacent substations. Therefore, this embodiment simplifies the secondary design, reduces the cable investment cost, and has strong anti-interference performance.

[0061] As Figure 3 shown, it is a schematic connection diagram of the monitoring component and the intelligent monitoring unit described in this embodiment, from which the corresponding communication method can be obtained.

[0062] Embodiment 2

[0063] Based on Embodiment 1, as Figure 4 shown, the present utility model further provides an intelligent monitoring networking system based on an outdoor disconnector, including the intelligent monitoring device 100 based on the outdoor disconnector, a first switch 200, a first fiber optic pigtail box 300, and a substation integrated automation system 400 described above. The intelligent monitoring device 100 is connected to the first switch 200 through an Ethernet cable. The first switch 200 is connected to the first fiber optic pigtail box 300 through an optical fiber. The first fiber optic pigtail box 300 is connected to the substation integrated automation system 400 through an optical fiber, forming an outdoor monitoring box.

[0064] The substation integrated automation system 400 includes a second switch 401, a second fiber optic pigtail box 402, and a communication controller 403. The first fiber optic pigtail box 300 is interconnected with the second fiber optic pigtail box 402 through an optical fiber. The second fiber optic pigtail box 402 is connected to the second switch 401 through an optical fiber. The second switch 401 is connected to the communication controller 403 through an Ethernet.

[0065] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An intelligent monitoring device based on an outdoor isolating switch, characterized in that: The invention comprises an outdoor isolating switch body (1), a monitoring component (2), an intelligent monitoring unit (3), a display terminal (4) and an operating mechanism box (5). The outdoor isolating switch body (1) comprises a moving contact and a stationary contact, the moving contact and the stationary contact are connected to an incoming busbar (11) and an outgoing busbar (12), the moving contact is connected to a rotating mechanism (31) via a control rod (30), the rotating mechanism (31) is directly connected to an operating mechanism box (5) via an operating rod (14), the operating mechanism box (5) comprises a main shaft (51) and a motor arranged in the circumference of the main shaft (51), the monitoring component (2) comprises an isolating switch monitoring module and an operating mechanism box monitoring module, which are respectively installed in the outdoor isolating switch body (1) and the operating mechanism box (5), the intelligent monitoring unit (3) is electrically connected to the monitoring component (2), the intelligent monitoring unit (3) processes the data collected by the monitoring component (2) accordingly and sends the data to the display terminal (4), specifically: The isolating switch monitoring module comprises a first temperature sensor (21), a second temperature sensor (22), a third temperature sensor (23) and a fourth temperature sensor (24); the operating mechanism box monitoring module comprises an angular displacement sensor (25), a first current sensor (26) and a second current sensor (27); the first temperature sensor (21) is mounted on the incoming busbar (11); the second temperature sensor (22) is arranged on the outgoing busbar (12); the third temperature sensor (23) is arranged on the moving contact; and the fourth temperature sensor (24) is mounted on the stationary contact; the first temperature sensor (21), the second temperature sensor (22), the third temperature sensor (23) and the fourth temperature sensor (24) respectively collect real-time temperatures of the incoming busbar (11), the outgoing busbar (12), the moving contact and the stationary contact, and send relevant temperature data to the intelligent monitoring unit (3); The angular displacement sensor (25) is installed on the main shaft (51) and is used to measure the angular displacement value of the main shaft (51) in real time and upload it to the intelligent monitoring unit (3) via RS422. The intelligent monitoring unit (3) determines and alarms abnormal values ​​based on the real-time angular displacement value and records the angular displacement signal. The first current sensor (26) is installed in a circuit loop formed by closing the motor, and the second current sensor (27) is installed in a circuit loop formed by opening the motor, respectively collecting the closing current and opening current of the isolating switch motor in real time, and transmitting the obtained current data analog signal to the intelligent monitoring unit (3) in real time.

2. The intelligent monitoring device based on outdoor disconnector according to claim 1 is characterized in that: The operating mechanism box monitoring module also includes a temperature and humidity sensor (28), which is arranged in the operating mechanism box (5) and is used to monitor the temperature and humidity in the operating mechanism box (5) and transmit the information to the intelligent monitoring unit (3) in real time via RS485.

3. The intelligent monitoring device based on outdoor disconnector according to claim 1 is characterized in that: It also comprises a camera (6), which is arranged outside the outdoor isolating switch body (1) and is used to monitor the status of various components of the isolating switch in real time.

4. The intelligent monitoring device based on outdoor disconnector according to claim 2 is characterized in that: The temperature and humidity sensor (28) is connected to the intelligent monitoring unit (3) using a 485 communication interface.

5. The intelligent monitoring device based on outdoor disconnector according to any one of claims 1 to 3, characterized in that: The first temperature sensor (21), the second temperature sensor (22), the third temperature sensor (23) and the fourth temperature sensor (24) are all connected to the intelligent monitoring unit (3) by wireless transmission.

6. The intelligent monitoring device based on outdoor disconnector according to any one of claims 1 to 3, characterized in that: The intelligent monitoring unit (3) is a single chip microcomputer.

7. An intelligent monitoring networking system based on outdoor isolating switches, characterized in that: The invention comprises an intelligent monitoring device (100) based on an outdoor isolating switch as described in any one of claims 1 to 3, a first switch (200), a first optical fiber pigtail box (300) and a substation integrated automation system (400), wherein the intelligent monitoring device (100) is connected to the first switch (200) via an Ethernet cable, the first switch (200) is connected to the first optical fiber pigtail box (300) via an optical fiber, and the first optical fiber pigtail box (300) is connected to the substation integrated automation system (400) via an optical fiber.

8. The intelligent monitoring networking system based on outdoor isolating switches according to claim 7 is characterized in that: The substation integrated automation system (400) comprises a second switch (401), a second optical fiber pigtail box (402) and a communication controller (403), wherein the first optical fiber pigtail box (300) and the second optical fiber pigtail box (402) are interconnected via optical fibers, the second optical fiber pigtail box (402) and the second switch (401) are connected via optical fibers, and the second switch (401) and the communication controller (403) are connected via Ethernet.

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