KR102621072B1 - Monitoring system for underground electric power line - Google Patents

Abstract

The present invention relates to an underground distribution line monitoring system. More specifically, it relates to a monitoring system to prevent secondary accidents due to subsidence of conduits in underground distribution lines where power cables are laid in conduits buried underground. In the present invention, the sinking of the conduit is detected using a detection wire that is installed inside the conduit like a power cable, and is made up of a single strand and breaks when a tensile force exceeding a certain limit is applied. A pair of wires at both ends of the detection wire The IoT detection module uses the voltage applied to the sensing resistor connected to both ends of the sensing line to determine whether the conduit has settled, and if it is judged to have settled, it generates an alarm signal containing its own identification code and sends MQTT (Message Queuing Telemetry Transport). ) is transmitted through IoT communication that applies the protocol.

Description

{Monitoring system for underground electric power line}

The present invention relates to an underground distribution line monitoring system. More specifically, it relates to a monitoring system to prevent secondary accidents due to subsidence of conduits in underground distribution lines where power cables are laid in conduits buried underground. In the present invention, the sinking of the conduit is detected using a detection wire that is installed inside the conduit like a power cable, and is made up of a single strand and breaks when a tensile force exceeding a certain limit is applied. A pair of wires at both ends of the detection wire The IoT detection module determines whether the conduit has settled by using the voltage applied to both ends of the sensing resistor connected to both ends of the detection line, and if it is judged to have settled, it generates an alarm signal containing its own identification code and detects MQTT (Message Queuing Telemetry). It is transmitted through IoT communication that applies the Transport) protocol.

Underground distribution lines are sometimes laid in underground utility or underground power outlets, but a significant portion of underground distribution lines are laid in power conduits using conduits buried in the ground. In particular, in short-distance distribution lines or intra-premises lines, most of them are installed in power conduits using electrical conduits.

However, underground pipes, including power pipes, are exposed to the risk of subsidence for various reasons. Underground pipes subside for various reasons, such as soil movement, among which movement of soil or soil is one of the common causes of underground pipe subsidence. Earth movement refers to the shaking or erosion of the soil around underground structures, which can destabilize underground pipes or underground structures and cause them to move to deeper and deeper locations. In addition, underground construction activities such as road or subway construction or excavation work for new building construction are also a major cause of underground pipe subsidence.

Additionally, fluctuations in groundwater levels may cause subsidence of underground pipes. When groundwater is suddenly depleted due to excessive extraction or other causes, the space occupied by groundwater becomes empty and the ground above it rapidly subsides. This causes underground pipes to gradually move downward from the ground, causing severe damage. In this case, sinkholes, etc. may occur, causing subsidence and damage in an exposed state. In addition, earthquakes or ground movements can also affect underground pipes.

For these various reasons, underground pipes can easily sink, which can cause problems in various underground infrastructure, including power cables, communication cables, and water pipes. Therefore, attention must be paid to the design, management, and maintenance of underground structures, and constant monitoring activities are required. In particular, in the case of underground distribution lines, if the conduit subsides and is deformed or damaged, this can cause secondary accidents such as damage or damage to the power cables laid inside or fire, so special caution is required.

Figure 1 shows a plan view of a typical underground distribution line installed in a conduit. As shown in Figure 1, the underground distribution line has a structure in which a manhole 10 installed underground and a conduit 20 connecting the manholes 10 are buried, and a power cable 30 is laid in the conduit 20. . Such an underground distribution line first performs construction to install the manhole 10 and the conduit 20 underground, and then inserts a wire into the conduit between the manhole 10 and the manhole 10. ) By connecting the power cable 30 to the end of the wire on one side and pulling the wire on the other side, the power cable 30 can be installed by entering the conduit.

However, since the length of the power cable 30 is limited, a connection point 31 between the power cables 30 occurs in the middle, and the connection point 31 is mostly located within the manhole 10. I do it. When connecting the power cables 30 to each other at the connection point 31, a connection sleeve (not shown), etc. may be used, a cable head (not shown), etc. may be used, or various other connection devices may be used to connect them. do.

Meanwhile, as shown in FIG. 2(a), when the ground is normal, the conduit 20 is buried in an almost horizontal state parallel to the ground surface G.L. between the manholes 10 and the manholes 10. Of course, if there is a difference in elevation between the manhole 10 and the manhole 10, it is buried at an angle, but this also maintains a straight line inclined parallel to the ground surface (G.L.). However, when a sinkhole 15 or the like occurs and the conduit 20 sinks, the conduit 20 is deformed and bent downward, as shown in FIG. 2(b), and thus enters the conduit 20. The power cable 30 is also deformed.

When the conduit 20 and the power cable 30 are deformed and change from a straight line to a curve, the path becomes longer, so a tensile force is applied to the conduit 20 and the power cable 30 by pulling forces from both sides. This occurs. In this case, since the conduit 20 uses a corrugated pipe, etc., it has elasticity and may stretch somewhat. However, if the settlement becomes severe, the conduit 20 may be damaged. However, since the power cable 30 lacks elasticity compared to the conduit 20, a significant tensile force is generated in the power cable 30, thereby increasing the risk of damage to the power cable 30. . In particular, since the connection point 31 is weak against tensile force, the risk of damage due to tension applied to the connection sleeve or cable head is very high. As a result, as shown in FIG. 2(c), disconnection, short circuit, or damage occurs at the connection point 31. The risk of secondary accidents such as ground faults increases.

Since the sinking of underground conduit pipes of underground distribution lines can cause serious secondary accidents, there is a need to monitor, monitor, and inspect them with special attention on a regular basis. A technology that can monitor underground pipes includes a technology that observes the ground surface. When an underground pipe subsides, changes may appear in the ground surface, and these changes are measured within the tolerance range of the ground surface. Subsidence is measured by measuring ground surface intervals. can be detected. This can be accomplished using markers installed on the earth's surface or a Global Navigation Satellite System (GNSS) that tracks the location of the markers. In addition, when subsidence occurs, there may be a change in the slope of the underground pipe. There is also a technology that can indirectly determine the settlement of the underground pipe by detecting the change in slope based on the horizontal plane using an inclinometer. However, these methods are not only impossible to use in places with frequent traffic of vehicles or people, such as roads, but also require installing and monitoring numerous markers and inclinometers, so they cannot be applied except in very specific places.

There is also a technology that precisely measures and monitors the shape and location of underground pipes using laser scanning or 3D scanning technology. This uses a laser scanner to scan the terrain around the underground pipe and creates a 3D model to check for subsidence. There will be. However, this is a method that can only be used in special cases, such as when regular monitoring is impossible and a subsidence accident is suspected.

Additionally, there is a method of directly measuring the displacement of the underground pipe, which involves installing a displacement measuring device in the underground pipe to measure the displacement of the underground pipe. This displacement measuring device is installed in or around an underground pipe and monitors it by detecting and recording the displacement. However, this also has the problem of being difficult to apply unless it is an underground pipe that requires special management because it is difficult to accurately monitor and is expensive unless a displacement measuring device is installed throughout the entire section of the underground pipe where there is a risk of subsidence.

Specifically, as a prior art related to this, there is Korean Patent Publication No. 10-2018-0102898 (2018. 09. 18), a sensor and sensing method for detecting deformation and damage signs, and a manufacturing method thereof, which includes the electrical resistance value of the sensor. It relates to a sensor element that can detect deformation of a structure using . And Korean Patent No. 10-2171735 (2020.10.29) relates to an inversion tube for pipe repair with a deformation or floating settlement monitoring function and an inversion pipe repair device using the same, which detects deformation or floating settlement using an optical fiber sensor. It is about a device that does. In addition, Korean Patent No. 10-0983015 (2010.09.17) relates to a device for detecting damage to underground electric wires for distribution in apartment complexes, and relates to a device that detects damage to underground electric wires using a wire and a pressure sensor.

Meanwhile, MQTT (Message Queuing Telemetry Transport) is a lightweight protocol for IoT communication and is an Internet protocol that operates in an environment with limited network bandwidth and client device resources. MQTT is designed for Internet of Things (IoT) and Machine-to-Machine (M2M) communications and is used to quickly transfer data between low-power devices and devices with limited network connectivity. And MQTT operates based on the client/server model and uses the publish-subscribe messaging pattern. In this pattern, the publisher publishes messages about a specific topic, and the subscriber subscribes to the topic of interest and receives messages about that topic.

And in MQTT, there is a concept called a broker, which mediates connections between clients and delivers messages. It operates in a none TCP/IP environment between the MQTT broker and the publish device. However, it operates on the TCP/IP protocol for simple and efficient message delivery between the MQTT broker and the server or subscribe device. This enables efficient communication using small packet sizes and minimal bandwidth. In addition, MQTT is connection-oriented and has the advantage of providing functions for low-power devices to minimize energy consumption and enable stable communication. Prior technology related to MQTT includes Korean Patent No. 10-2129456 (2020.07.02), which concerns an MQTT protocol-based server system in an Internet of Things environment. However, because the existing MQTT is optimized for M2M-based communication that presupposes numerous messages exchanged between a large number of client devices and a large number of brokers, only a small number of messages are transmitted between a relatively small number of client devices and a small number of brokers. This requires some customization.

Meanwhile, wireless communication networks are generally used in IoT communication, but there are also various technologies for implementing the Internet of Things (IoT) using wired communication networks. These technologies are applied to various industrial fields considering reliability, bandwidth, power consumption, etc. These communication methods include Ethernet, Power Line Communication (PLC), DSL (Digital Subscriber Line), and optical fiber. (Fiber Optic), etc.

Among them, Ethernet is the most common wired network technology and transmits data using copper wires or optical fiber cables. Ethernet connects network devices to enable data communication, and the Internet of Things often uses Ethernet to connect devices and transmit data. Recently, a protocol called PoE (Power over Ethernet) has emerged, and technology to transmit power to IoT sensors through a single data line has also been developed and utilized. The prior technology for implementing the Internet of Things using PoE is a Korean registered patent. There is No. 10-2546893 (June 23, 2023).

Power Line Communication (PLC) is a technology that transmits data using wires in the electric distribution network. PLC transmits data through power lines, so there is no need to build a separate communication infrastructure. It is mainly used in home, commercial, and industrial power grids. PLC can be used to connect IoT devices and transmit data. Prior technology for implementing the Internet of Things with PLC includes Korea Registered Patent No. 10-2083114 (April 23, 2020).

And DSL (Digital Subscriber Line) is a technology that provides high-speed Internet connections through phone lines. DSL transmits data using a high frequency band on a phone line, making it possible to connect IoT devices using existing phone infrastructure. DSL is mainly used in homes and offices, and IoT devices are also connected to the Internet through DSL. You can connect and exchange data. Additionally, Fiber Optic is a technology that transmits data using light, providing high-speed bandwidth and multi-mode or single-mode transmission. Optical fiber is suitable for long-distance communication and is a technology suitable for the IoT environment where large amounts of data must be processed. These above technologies provide a method to connect various devices and transmit data using a wired communication network in the Internet of Things. IoT solutions based on wired communication networks are being developed and applied in various fields such as industrial automation, smart homes, and smart cities.

Republic of Korea Patent Publication No. 10-2018-0102898 (2018.09.18) Republic of Korea Patent No. 10-2171735 (2020.10.29) Republic of Korea Patent No. 10-0983015 (2010.09.17) Republic of Korea Patent No. 10-2129456 (2020.07.02) Republic of Korea Patent No. 10-0821989 (April 15, 2008) Republic of Korea Patent No. 10-2546893 (2023.06.23.) Republic of Korea Patent No. 10-2083114 (2020. 04. 23)

The present invention, created to solve the above-mentioned problems, provides an underground distribution line monitoring system that detects settlement of conduits in underground distribution lines, thereby preventing secondary accidents such as damage to power cables due to subsidence of conduits. The purpose is to provide

Another object of the present invention is to provide an underground distribution line monitoring system that can accurately detect the subsidence of the underground distribution line at the initial stage when the subsidence begins.

The present invention also provides an underground distribution line monitoring system that can be constructed relatively simply at an economical cost, even without using expensive and complicated methods such as laser scanning, 3D scanning technology, or displacement measurement using multiple displacement sensors. The purpose is to

Another object of the present invention is to provide an underground distribution line monitoring system that can report subsidence of an underground distribution line using only a single sensing line, without using multiple complex sensing lines.

The present invention is also capable of not only partially monitoring a specific or short section of an underground distribution line, but also detecting and monitoring areas where settlement occurs among all conduits laid across the entire section of an underground distribution line. The purpose is to provide a comprehensive monitoring system for underground distribution lines.

The present invention also aims to provide an underground distribution line monitoring system that can notify the monitoring server of the subsidence of the underground distribution line through Internet of Things communication.

The purpose of the present invention is also to provide an underground distribution line monitoring system that can quickly and accurately inform whether the underground distribution line has subsided by optimizing and communicating with the Internet of Things communication protocol.

The purpose of the present invention is also to provide an underground distribution line monitoring system that can detect subsidence of the underground distribution line from a monitoring server even after the Internet of Things monitoring device is depleted of power and communication is impossible.

The present invention also aims to provide an underground distribution line monitoring system that can continuously supply power to an Internet of Things monitoring device without an external power source when the underground distribution line is not subsiding.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

The present invention, created to achieve the above-described purpose, is a monitoring system for preventing secondary accidents due to sinking of the conduit in an underground distribution line in which power cables are laid in conduits buried underground, wherein the power cable and Likewise, a sensing wire installed inside the conduit, which consists of a single strand and is disconnected when a tensile force exceeding a certain limit is applied; A pair of sensing resistors connected to both ends of a sensing line installed between two adjacent manholes; a pair of grounding means connecting one end of each of the pair of sensing resistors opposite to the end connected to the one sensing line and grounding one end of each of the pair of sensing resistors; It is connected to both ends of the pair of sensing resistors, and detects settlement of the conduit using the both-end voltage, which is the voltage measured at both ends of each sensing resistor. If settlement is determined, an alarm signal containing its identification code is sent. A pair of IoT detection modules that generate and transmit; And the alarm signal transmitted by the IoT detection module can be received, and when the alarm signal is received, the transmission location of the alarm signal is identified using the identification code included in the alarm signal, and the transmission location is included. a monitoring server that generates and displays subsidence information; each of the pair of IoT detection modules includes: - a voltage measuring unit that measures the voltage at both ends; - A signal generator that repeatedly generates the warning signal at first time intervals when the voltage at both ends falls below a certain value; and - a signal transmitting unit that transmits the warning signal through Internet of Things communication whenever the warning signal is generated.

In addition to the above-described features, the present invention also provides an underground distribution line monitoring system, wherein the resistance value of each of the pair of sensing resistors is greater than the grounding resistance of each of the pair of grounding means, or in addition to the monitoring server. It is also desirable to use an underground distribution line monitoring system that generates the subsidence information only when the alarm signal is received from both of the pair of IoT detection modules.

The present invention also provides that, in addition to the above-described features, the IoT communication is IoT communication using the MQTT (Message Queuing Telemetry Transport) protocol, and further includes an MQTT broker that relays the alarm signal, and the IoT detection module The alarm signal is transmitted to the MQTT broker, and the monitoring server receives the alarm signal through the MQTT broker. The data format of the alarm signal used in the MQTT protocol is as follows,

- QoS is set to 0, - LWT (Last Will Testament) is a message containing the meaning of 'communication was interrupted due to subsidence', - Topic is the name of the distribution line in a hierarchical structure and the IoT detection module. It is also desirable to use an underground distribution line monitoring system that combines identification codes in the form of feeder line name/main line name/branch line name/branch line name/identification code.

The present invention also provides that, in addition to the above-described features, the IoT detection module is divided into a first detection module installed at one end of the one detection line and a second detection module installed at the other end of the one detection line. Each of the first detection module and the second detection module further includes a relay signal receiver and a control unit, and the signal transmission unit of the first detection module transmits the alarm signal through the one detection line, and the second detection module The relay signal receiver can receive the alarm signal transmitted by the first detection module through the one detection line, and the signal transmitter of the second detection module can be connected to the relay signal receiver of the first detection module in the same manhole. is connected to and transmits the alarm signal through the connection line, and the relay signal receiving unit of the first detection module can receive the alarm signal transmitted by the second detection module through the connection line, and the first detection module And the control unit of the second detection module, when receiving an alarm signal transmitted by the second detection module or the first detection module from the relay signal reception unit, controls to relay and transmit it through the signal transmission unit. It is also desirable to use an underground distribution line monitoring system.

In addition to the above-mentioned features, the present invention also provides an underground distribution line monitoring system, wherein one point of each end of the single sensing line is fixed to the conduit, or in addition, the pair of IoT detection systems is provided. It further includes a power module that supplies operating power to each module, wherein each power module includes a storage battery and a charging circuit for charging the storage battery, and the charging circuit is located at both ends of the sensing resistor. It is also desirable to use an underground distribution line monitoring system that operates with an applied voltage to charge the storage battery.

As discussed above, in the present invention, a detection wire that is disconnected when a tensile force exceeding a certain limit is applied is placed inside the conduit, and when the conduit sinks, the detection wire is disconnected due to the tensile force applied to both ends of the detection wire. If the sensing line is disconnected while monitoring for wire disconnection, the IoT detection module determines that the conduit has settled and generates an alarm signal, so it is effective in quickly and accurately detecting the sinking of the conduit at the beginning.

In addition, the sensing line included in the present invention consists of only one strand, and the sensing line is placed in parallel with the power cable inside the conduit, and a sensing resistor with one side grounded is connected to both ends of the sensing line, and the voltage applied to both ends of each sensing resistor is connected. It has a configuration that includes an IoT detection module that monitors the voltage across both ends. Accordingly, in normal times, an induced voltage is generated in the sensing line due to the zero-phase current flowing in the power cable, and since the induced current flows in the sensing line and the sensing resistor due to the induced voltage, a potential difference is generated across the sensing resistor. However, when the conduit sinks, the sensing wire is disconnected due to the tensile force applied to both ends of the sensing wire. When the sensing wire is disconnected, the circuit is opened and current does not flow, so the voltage across the sensing resistor becomes 0V. Additionally, the IoT detection module determines sinking when the voltage across the sensing resistor falls below a certain value (0V) and sends out an alarm signal. Therefore, the present invention has the effect of detecting and warning the sinking of the conduit through a simple configuration that inserts only a single sensing wire and sensing resistance at both ends of the conduit without complex devices such as multiple displacement detection sensors or scanners. .

In addition, the IoT detection module included in the present invention transmits an alarm signal through Internet of Things communication. The IoT communication protocol used in the present invention uses the MQTT (Message Queuing Telemetry Transport) protocol, and accordingly, the IoT detection module transmits an alarm signal to the MQTT broker, and the monitoring server receives the alarm signal through the MQTT broker. The LWT (Last Will Testament) included in the alarm signal contains the meaning “communication was interrupted due to subsidence.” Because it has a structure that includes a message, even if the IoT monitoring module's power is depleted due to repeated transmission of the alarm signal and the transmission of the alarm signal is stopped, the monitoring server has the effect of being able to know the reason for the interruption. there is.

In addition, the topic included in the alarm signal is included in the form of feeder line name/main line name/branch line name/branch line name/identification code by combining the name of the hierarchically structured distribution line and the identification code of the IoT detection module, so there are numerous IoT From the perspective of the monitoring server that receives the message from the detection module, it is possible to find only the Topic with an error status code and find the installation location of the IoT monitoring module with the corresponding identification code in the distribution line. Therefore, the distribution line where the conduit has sunk and the You can quickly find the location. In addition, it becomes possible to determine the subsidence status of a specific main line or branch line as a whole, or to determine the overall status of subsidence at specific times.

In addition, the IoT detection module included in the present invention can be divided into a first detection module and a second detection module, which further include a relay signal receiver and a control unit, and the signal transmission unit of the first detection module is connected to another manhole through a detection line. An alarm signal is transmitted to the second detection module located in the second detection module, and the relay signal receiver of the second detection module located in the other manhole can receive the alarm signal through the detection line, and the signal transmission unit of the second detection module is located in the same manhole. It is connected to the relay signal receiver of another first detection module by a connection line, and an alarm signal is transmitted through the connection line. The alarm signal transmitted through the connection line can be received by the relay signal receiver of the first detection module through the connection line, The control unit of the first detection module or the second detection module has a configuration that can control the relay signal reception unit to relay and transmit the alarm signal transmitted by another IoT detection module through the signal transmission unit. Therefore, in the present invention, the alarm signal transmitted from one IoT detection module is sequentially relayed by wire through the detection line and other IoT detection modules, so that it can reach the manhole where the gateway or MQTT broker is installed in the underground distribution line. , the gateway or MQTT broker can transmit the relayed alarm signal to the monitoring server. Therefore, the present invention can provide a comprehensive monitoring system that detects settlement of all sections of the underground distribution line.

In addition, the present invention has the characteristic that one point of each end of a sensing line is fixed to the conduit, so when the conduit is deformed and curved due to sinking of the conduit, both ends are fixed when the length of the conduit increases. Tensile force is applied to the sensing line, and when the deformation of the conduit exceeds a certain limit, the sensing line is disconnected, which has the effect of immediately detecting the sinking of the conduit.

The present invention further includes power modules that supply operating power to each of a pair of IoT sensing modules, and each power module includes a storage battery and a charging circuit, and the charging circuit is connected to both ends of the sensing resistor. Since the battery is charged by operating the charging circuit with the voltage applied to the sensing resistor and the output power of the storage battery is used to operate the IoT sensing module, even if there is no separate external power supply to the IoT sensing module, the induced current flowing in the sensing line is used. It is constantly charged, which has the effect of continuously supplying power to the IoT detection module without an external power source.

In addition, the present invention also has the characteristic that the resistance value of each pair of sensing resistors is greater than the grounding resistance of each pair of grounding means, so the voltage value across the sensing resistors may be larger, resulting in disconnection of the sensing line. If this is not the case, the voltage value across the sensing resistor can be easily detected.

Figure 1 is a plan cross-sectional view from above of an underground distribution line to which the present invention is applied.
Figure 2 is a side cross-sectional view of an underground distribution line to show the phenomenon that occurs when the conduit subsides.
Figure 3 is a side cross-sectional view of an underground distribution line to show the concept of the detection line according to the present invention.
Figure 4 shows a perspective view of an underground distribution line to show the concept of the detection line according to the present invention.
Figure 5 shows a connection diagram of a sensing line, sensing resistor, IoT sensing module, and monitoring server according to the present invention.
Figure 6 shows the detailed configuration of the IoT sensing module according to the present invention.
Figure 7 shows a closed circuit formed in a state where the conduit does not sink as an equivalent circuit.
Figure 8 shows the state in which the conduit is sunk and the closed circuit is opened and its equivalent circuit.
Figure 9 shows an example of a distribution line complexly formed in the shape of a tree branch.
Figure 10 shows an example of hierarchical structure of distribution line names for inclusion in the Topic in the present invention.
Figure 11 shows a conceptual diagram of the MQTT protocol applied to the present invention.
Figure 12 shows an embodiment including a first detection module and a second detection module in the present invention.
Figure 13 shows the concept of signal relay in an embodiment including a first detection module and a second detection module.
Figure 14 shows an embodiment including a power module in the present invention.
Figure 15 shows an embodiment in which an external power source is included in the sensing line in the present invention.

Hereinafter, the present invention will be described in detail so that the above-mentioned purpose and features become clear, so that those skilled in the art will be able to easily implement the technical idea of the present invention. In addition, when describing the present invention, if a detailed description of the known technology related to the present invention is already well known in the technical field, and it is judged that the detailed description of the known technology may unnecessarily obscure the gist of the present invention, the detailed description will be provided. Decided to omit it.

In addition, the terms used in the present invention are general terms that are currently widely used as much as possible, but in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning is described in detail in the description of the relevant invention, so it is a simple term. We would like to make it clear that the present invention should be understood by the meaning of the term, not by its name. Terms used in the description of the embodiments are merely used to describe specific embodiments and are not intended to limit the embodiments. Singular expressions include plural expressions unless the context clearly dictates otherwise.

The embodiments can be modified in various forms and have various additional embodiments, where specific embodiments are shown in the drawings and related detailed descriptions are described. However, this is not intended to limit the embodiments to a specific form, and should be understood to include all changes, equivalents, or substitutes included in the spirit and technical scope of the embodiments.

In the description of various embodiments, expressions such as “first,” “second,” “first,” or “second” may modify various elements of the embodiments, but do not limit the elements. For example, the above expressions do not limit the order and/or importance of the corresponding components. The above expressions can be used to distinguish one component from another.

Hereinafter, the present invention will be described with reference to the attached drawings. Figure 1 is a plan view from above of an underground distribution line to which the present invention is applied. As shown in Figure 1, the underground distribution line has a structure in which a manhole 10 installed underground and a conduit 20 connecting the manhole 10 are buried, and a power cable 30 is laid inside the conduit 20. am.

In such an underground distribution line, a manhole (10) is first installed, a manhole (10) is installed by excavation work to bury the conduit (20), and a conduit (20) is installed between the manhole (10) and the manhole (10). After performing the burial and backfilling work, a pulling wire (not shown) is inserted into the conduit 20 between the manhole 10 and the power cable 30 is connected to the end of the wire from one side of the manhole 10. By connecting and pulling the wire with a pulling machine (not shown) from the other side, the power cable 30 can be placed inside the conduit 20.

However, since the power cable 30 is limited in length, many connection points 31 between the power cables 30 occur in the middle, and most of the connection points 31 are located within the manhole 10. . When connecting the power cables 30 to each other at the connection point 31 of the manhole 10, a connection sleeve (not shown), etc. may be used, a cable head (not shown), etc. may be used, or various other connection devices may be used. It can also be connected.

Meanwhile, Figure 2 shows a side cross-sectional view to show the concept of an accident that occurs when the conduit of an underground distribution line sinks. As shown in FIG. 2(a), when the ground inside the ground surface (G.L.) is normal, the conduit (20) is buried in an almost horizontal state parallel to the ground surface (G.L.) between the manholes (10) and the manhole (10). there is. Of course, if there is a difference in elevation between the manhole 10 and the manhole 10, it is buried at an angle, but this also maintains a straight line inclined parallel to the ground surface (G.L.). However, when a sinkhole 15, etc. occurs and the conduit 20 sinks, the conduit 20 is deformed and bent downward, as shown in FIG. 2(b), and accordingly, the conduit 20 contained in the conduit 20 The power cable 30 is also modified.

When the conduit 20 and the power cable 30 are deformed in this way and change into a curve, the path becomes longer, so the conduit 20 and the power cable 30 have a pulling force (f) on both sides, that is, a tensile force (f ) occurs. At this time, in the case of the conduit (20), since corrugated pipes, etc. are used, it has elasticity and may stretch somewhat (however, it is damaged if the settlement becomes severe), but in the case of the power cable (30), the conduit (20) Because of the lack of elasticity, a significant tensile force (f) is generated at both ends of the power cable (30), thereby increasing the risk of damage to the power cable (30). In addition, since the connection point 31 is particularly weak against the tensile force f, the risk of damage due to tension applied to the connection sleeve or cable head is very high. As a result, as shown in FIG. 2(c), the connection point 31 is In the manhole 10, the risk of secondary accidents such as disconnection, short circuit, or ground fault increases.

The present invention, which was created to solve this problem, prevents secondary accidents due to sinking of the conduit (20) in an underground distribution line in which the power cable (30) is laid in the conduit (20) buried underground. As a monitoring system for IoT, a detection wire 100 is inserted into the conduit 20 like the power cable 30, and when the detection wire 100 is pulled and disconnected due to the sinking of the conduit 20, IoT The detection module 300 is configured to detect this, generate an alarm signal, and transmit it to the monitoring server 500 through Internet of Things communication. In order to show the concept of the detection line 100 according to the present invention, Figure 3 shows a side cross-sectional view of an underground distribution line, and Figure 4 shows a perspective view.

The detection line 100 included in the present invention is installed inside the conduit 20 like the power cable 30, as shown in FIGS. 3 and 4, but is made of one strand and exceeds a certain limit. It is desirable to use a wire made of a material that can be easily broken when tensile force (F) is applied. That is, as shown in FIGS. 3(a) and 4, the detection line 100 is located inside the conduit 20 like the power cable 30, in the same direction parallel to the power cable 30. It is desirable to place it along . In addition, when the ground subsides due to movement of soil or sinkholes, and the conduit 20 also subsides accordingly, and the conduit 20 is deformed and turns into a curve as shown in FIG. 3(b), the conduit 20 A tensile force (F) exceeding the certain limit is applied to both ends of the sensing line 100 lying inside, and accordingly, it is desirable to cause a disconnection point (X) in the sensing line 100. Here, the 'certain limit' refers to the 'permissible length range' within which the conduit 20 can be extended to some extent when the conduit 20 is deformed due to sinking, and the detection line 100 is set to the ' It is desirable to set a limit on the tensile force (F) so that it breaks if it exceeds the 'permissible length range'.

Meanwhile, since the detection line 100 is preferably placed together with the power cable 30 as shown in FIG. 4, the detection line 100 is connected to the power cable 30 in the conduit 20. This results in many places being pressed or stuck. Therefore, when the conduit 20 begins to deform, before the tensile force pulling from the vicinity of both manholes 10, which are both ends of the sensing line 100, is generated, a partial tensile force occurs at the place where the conduit 20 is deformed. This occurs first, and accordingly, there is a high probability that the disconnection point (X) will occur first in the place where the conduit 20 is most deformed. In some cases, multiple disconnection points (X) may occur here and there on the sensing line 100. However, regardless of where the disconnection point (X) occurs, it is preferable that the disconnection point (X) is electrically disconnected and insulated. That is, when a tensile force exceeding the certain limit acts on the detection line 100, the detection line 100 is located between the manhole 10 at both ends of the detection line 100 and another manhole 10. It is desirable to ensure that at least one point is completely cut off so that no current flows between both ends of the sensing line 100.

In this way, even if there are many places in the conduit 20 where the sensing line 100 is pressed or caught by the power cable 30, one point at each end of the single sensing line 100 is, It is more preferable to fix it to the conduit 20. In this case, when a tensile force exceeding the certain limit acts on the detection line 100, the detection line 100 is between the manholes 10 at both ends of the detection line 100 and another manhole 10. It is completely cut off in one or more places. However, it is also possible to attach the sensing line 100 to the inner peripheral surface of the conduit 20 not only at both ends of the sensing line 100 but also over the entire section of the conduit 20. In this case, the accuracy of disconnection of the detection line 100 when the conduit 20 sinks can be further increased.

Figure 5 shows the sensing line 100, a pair of sensing resistors 200 connected to both ends of the sensing line 100 and grounded, and a pair of IoT devices connected to both ends of each of the pair of sensing resistors 200. A sensing module 300 is shown. As shown in FIG. 5, it is preferable to connect a pair of sensing resistors 200 to each end of the single sensing line 100 installed between two adjacent manholes 10. And, among both terminals of each of the pair of sensing resistors 200, a pair of grounding means 400 for grounding each of the sensing resistors 200 is provided at the terminal opposite to the terminal to which the one sensing line 100 is connected. It is desirable to connect them separately. That is, it is preferable that one end of both terminals of each of the pair of sensing resistors 200 is connected to the one sensing line 100 and the other end is grounded through the grounding means 400.

In addition, it is preferable that two wires drawn from each IoT sensing module 300 are connected to both ends of each terminal of the pair of sensing resistors 200. This means that each of the IoT sensing modules 300 has a voltage across both ends of the sensing resistor 200, which is a voltage value measured between both terminals of the sensing resistor 200 ( This is because it is desirable to detect the sinking of the conduit 20 using ). And the IoT detection module 300 applies the voltage at both ends of the detection resistor 200 ( ), if it is determined to be subsidence as a result of measurement, it is desirable to generate an alarm signal including its own identification code and transmit it to the monitoring server 500 through the communication network 700. It is also desirable for the alarm signal to include distribution line information, status code, or judgment time. Additionally, the communication network 700 can be a wired communication network or a wireless communication network. More preferably, it is better to use an Internet of Things (IoT) communication network, whether wired or wireless.

Meanwhile, the IoT detection module 300 applies a voltage at both ends of the detection resistor 200 ( ), if it is not judged to be subsidence as a result of the measurement, an inspection signal containing its identification code, normal code, and judgment time is generated at regular time intervals and transmitted to the monitoring server 500 through the communication network 700. It is also desirable. In this case, the monitoring server can also know whether the IoT detection module 300 is operating normally.

And the monitoring server 500 can receive the alarm signal and/or the inspection signal transmitted by the IoT detection module 300, and when the monitoring server 500 receives the warning signal, the It is desirable to use the identification code included in the alarm signal to determine the transmission location of the alarm signal, that is, the location of the IoT detection module that transmitted the alarm signal, and to generate and display subsidence information including the transmission location. . The display means for expressing the subsidence information is preferably a display means such as an LCD monitor, but it is also possible to express the warning signal by voice, etc., and it can also be used as a communication means that can notify terminals such as managers of underground distribution lines. desirable

Meanwhile, Figure 6 shows the detailed configuration of the IoT detection module 300. As shown in FIG. 6, each of the IoT sensing modules 300 has the voltage across both ends of the sensing resistor 200 ( ), the voltage measuring unit 310 measuring the voltage across both ends measured by the voltage measuring unit 310 ( ) is below a certain value, a signal generator 320 that repeatedly generates the alarm signal at first time intervals, and a signal generator 320 that transmits the alarm signal through IoT communication 700 each time the alarm signal is generated. It is desirable to include a signal transmission unit 330. When the IoT communication 700 that transmits the warning signal is wireless, it is preferable that the signal transmission unit 330 includes an antenna 331.

Here, the first time can be appropriately set, such as 1 minute or 5 minutes, within a range that does not cause excessive power consumption, taking into account the status, consumption rate, and depletion time of the operating power of the IoT sensing module 300. Also, it is preferable that the first time becomes longer as time passes from when the warning signal is first generated. In this case, when the operating power of the IoT detection module 300 is limited, the warning signal can be continuously transmitted for a longer period of time until measures against subsidence are taken.

In the present invention having the above configuration, conceptual diagrams explaining the operating principle of sinking detection of the conduit 20 are shown in FIGS. 7 and 8. Figure 7(a) shows a state in which the sensing line 100 is not broken in the present invention, and Figure 7(b) shows an equivalent circuit for Figure 7(a). As shown in Figure 7(a), in the present invention, both ends of the single sensing line 100 are grounded through respective sensing resistors 200. Therefore, when the conduit 20 does not sink, the sensing line 100 is not broken, so as shown in the equivalent circuit of FIG. 7(b), the sensing line 100 - sensing resistance 200b - grounding means 400b - Grounding means 400a - Forms an electrical closed circuit that passes through the sensing resistance 200a and is connected back to the sensing line 100.

In addition, an induced voltage is induced in the sensing line 100 by the current or zero phase current flowing in the power cable 30, and the potential at both ends of the sensing line 100 ( ) is somewhat different, so the potential difference ( ) is generated, and both ends of the sensing line 100 are grounded by the grounding means 400 via the sensing resistor 200, so the potential difference between both ends of the sensing line 100 ( ) is a voltage source ( ) acts as follows. Therefore, in the closed circuit consisting of the sensing line 100, the sensing resistor 200, and the grounding means 400, a circulating current ( ) flows.

At this time, the circulating current ( ) The current value of Therefore, the potential difference between both ends of the sensing line 100 ( ) and the resistance values of each of the sensing resistors 200 connected to both ends of the sensing line 100 ( ) And the line resistance of the detection line 100 ( ) and the grounding resistance of each of the grounding means 400 ( ) and can be calculated using the following equation.

And both ends of each of the sensing resistors 200 connected to both ends of the sensing line 100 have their resistance values ( ) and circulating current ( ) by the voltage at both ends ( ) is formed. The voltage at both ends ( ) The voltage value can be calculated by the following equation.

However, as shown in FIG. 8(a), when one or more of the sensing lines 100 are disconnected due to the sinking of the conduit 20 and the disconnection point X occurs, FIG. 8(b) As shown in the equivalent circuit of ), the closed circuit consisting of the sensing line 100, the sensing resistor 200, and the grounding means 400 is opened and no induced current is generated, so the circulating current ( ) also stops flowing, so the circulating current ( ) The current value becomes 0A. Therefore, the voltage at both ends ( ) The voltage value also becomes 0V. And an induced voltage ( ) Even if the current value is 0, the potential at both ends of the sensing resistor 200 is the same. Therefore, the potential difference between both ends of the sensing resistor 200 becomes 0V.

Therefore, in the state shown in FIG. 8, the voltage measurement unit 310 in the IoT detection module 300 measures the voltage value across the detection resistor 200 as less than a certain voltage (0V), so the signal generator 320 The alarm signal is repeatedly generated at first time intervals, and the signal transmission unit 330 transmits the alarm signal through IoT communication.

Meanwhile, the resistance value of the pair of sensing resistors 200 ( ) is the grounding resistance of each of the grounding means 400 ( ) It is desirable to make it larger. In this way, the voltage applied to both ends of each of the sensing resistors 200 ( ) becomes higher, making it possible to more easily detect the voltage value across both ends of the sensing resistor 200.

For example, the potential difference between both ends of the detection line 100 ( ) is 3V, and the line resistance of the detection line 100 ( ) is 10Ω, and the grounding resistance of each of the grounding means 400 ( ) is 100Ω, the resistance value of each of the sensing resistors (200) ( ) is the same as 10Ω, the voltage at both ends of each of the sensing resistors (200) ( ) is (3V x 10Ω)/(10Ω + 10Ω + 10Ω + 100Ω + 100Ω) = 0.13V, which may make voltage detection difficult. However, the resistance value of each of the sensing resistors 200 ( ) is the ground resistance ( ), the voltage applied to both ends of each of the sensing resistors (200) is 200Ω ( )'s voltage value is (3V

In addition, it is preferable that the monitoring server 500 generates the subsidence information only when the alarm signal is received from both of a pair of IoT detection modules 300 connected to both ends of the single detection line 100. do. In this case, not only can the reliability of the subsidence information generated by the monitoring server 500 be increased, but also information on the need for maintenance for the pair of IoT detection modules 300 can be collected. . That is, when only one of the pair of IoT detection modules 300 transmits an alarm signal, it can be regarded as a signal requiring inspection of the IoT detection module 300.

Because it consists of a closed circuit consisting of the sensing line 100, the sensing resistor 200, and the grounding means 400, if the closed circuit is opened due to the sinking of the conduit 20, the both ends voltage ( ) is normal for both voltage values to be measured as 0V, and if both are 0V, both should transmit an alarm signal. However, if only one of them transmits an alarm signal, it means that the IoT detection module 300 that transmits the alarm signal is broken. Otherwise, the IoT detection module (300) that did not transmit the above alarm signal could not detect the voltage value, or one of the two was broken.

Meanwhile, the IoT communication used when the IoT detection module 300 transmits the alarm signal or inspection signal to the monitoring server 500 is IoT communication using the MQTT (Message Queuing Telemetry Transport) protocol. desirable. When using the MQTT protocol in this way, as shown in FIG. 9, in a distribution line that has a very complex structure like a tree branch with feed lines, trunk lines, branch lines, branch lines, etc., the IoT detection module 300 When transmitting the above alarm signal to the monitoring server 500, the name of the distribution line on which it is located can be displayed in a hierarchy such as 'feeder line name/main line name/branch line name/branch line name', etc., as shown in Figure 10. Not only that, but you can also include your own identification code and send it to Topic. In addition, the data transmitted with Topic can include detailed information such as status code (error) and judgment time of sinking.

Accordingly, from the perspective of the monitoring server 500, which receives the alarm signal or the inspection signal from numerous IoT detection modules 300, only Topics with an error status code are found and an IoT monitoring module with the corresponding identification code is detected in the distribution line ( Since the installation location of 300) can be found, it is possible to quickly find the distribution line where the conduit 20 has sunk and its location. In addition, it becomes possible to determine the subsidence status of a specific main line or branch line as a whole, or to determine the overall status of subsidence at specific times. In this case, it is desirable that the data included in the warning signal further include the judgment time at which sinking was determined.

When using the MQTT protocol in this way, as shown in FIG. 11(a), an MQTT broker 600 that relays the alarm signal or the inspection signal between the IoT detection module 300 and the monitoring server 500 is further included. It is desirable to do so. And the IoT detection module 300 transmits the alarm signal to the MQTT broker 600, and the monitoring server 500 is configured to receive the alarm signal or the inspection signal through the MQTT broker 600. It is desirable. Accordingly, when the IoT detection module 300 needs to transmit the alarm signal or the inspection signal, it becomes a publisher on the MQTT protocol and connects to the MQTT broker 600 to publish topics and data, and then becomes a subscriber. The monitoring server 500 can connect to the MQTT broker 600 and subscribe to topics and data published by the IoT detection module 300.

Additionally, it is possible for the monitoring server 500 to become a publisher and publish its own topics and data. However, in the present invention, it is preferable that the IoT detection module 300 only performs the role of a subscriber, so the topics and data published by the monitoring server 500 are not intended to enable the IoT detection module 300 to subscribe, but are instead used by other monitoring servers. (500) Alternatively, it will be published for the purpose of allowing the administrator terminal (not shown) to subscribe. It is desirable to embed the MQTT broker 600 in a specific device or apparatus and install it in a location where signals can reach both the IoT detection module 300 and the monitoring server 500.

Meanwhile, the general data format used in the MQTT protocol is as shown in FIG. 11(b), and it is desirable to customize the data format of the alarm signal included in the present invention as shown in FIG. 11(c). Here, it is desirable to set QoS (Quality of Service) to 0. The reason why QoS is set to 0 is because when subsidence is determined, the warning signal is repeatedly generated and transmitted at first time intervals. Therefore, every time the alarm signal is transmitted, it is only necessary to publish it to the MQTT broker 600. In other words, since the alarm signal is repeatedly generated and transmitted at first time intervals, there is no need for the IoT detection module 300 to store the alarm signal (QoS = 2) each time it transmits the alarm signal. This is because there is no need to perform a handshake process like TCP (QoS=2) every time it is transmitted. This is because it only causes unnecessary overload.

In addition, it is desirable that the LWT (Last Will Testament) of the warning signal includes a message with a special meaning. In the MQTT protocol, LWT means will, which means sending messages in advance when the network is disconnected. Therefore, in case the IoT detection module 300 transmits the alarm signal at the first time interval and the power of the IoT detection module 300 is depleted and communication is interrupted, the LWT contains the message “Communication is interrupted due to subsidence.” It is desirable to configure it to include a message (e.g. “batt_out”) that means “stopped.”

Meanwhile, in Figures 12 and 13, the alarm signal or the inspection signal transmitted from one IoT detection module 300 is sequentially relayed through the detection line 100 and other IoT detection modules 300. , so that it can be relayed to a location where it can reach the gateway (not shown) or the MQTT broker 600, and the gateway or the MQTT broker 600 relays the received alarm signal or the inspection signal to the monitoring server. An embodiment that allows transmission to 500 is shown. When using this embodiment, the detection line 100 can be used for subsidence detection and can also be used as a wired communication network, so by sending an Internet of Things relay signal to the detection line 100, settlement of the entire section of the distribution line can be reduced. It is possible to provide a comprehensive surveillance system that can comprehensively perform detection.

For this purpose, as shown in FIG. 12, the IoT detection module 300 includes a first detection module 300b installed on one end of the one detection line 100 and a second detection module installed on the other end of the one detection line 100. It is desirable to divide it into two detection modules (300a). That is, the first sensing module 300b is connected to one side of the single sensing line 100, and the second sensing module 300a is connected to the other side.

In addition, each of the first detection module 300b and the second detection module 300a further includes a relay signal reception unit 340 and a control unit 350, and the signal transmission unit of the first detection module 300b (330) transmits the alarm signal or the inspection signal through the one detection line 100 - if necessary, via the coupling condenser 333, and the relay signal reception unit of the second detection module 300a (340) is designed to receive the alarm signal or inspection signal transmitted by the first detection module (300b) through the single detection line (100) - if necessary, via the coupling condenser (343). desirable.

In addition, the signal transmission unit 330 of the second detection module 300a is connected to the relay signal reception unit 340 of the first detection module 300b within the same manhole 10 through a connection line 332. The alarm signal or the inspection signal is transmitted through (332), and the relay signal receiver 340 of the first detection module (300b) recalls the alarm signal or inspection signal transmitted by the second detection module (300a). It can be received through the connection line 332, and the control unit 350 of the first detection module 300b and the second detection module 300a is connected to the second detection module 300a in the relay signal reception unit 340. Alternatively, when receiving an alarm signal or inspection signal transmitted by the first detection module 300b, it is preferable to control it to be relayed and transmitted through the signal transmission unit 330.

In this case, as shown in FIG. 13, the alarm signal or the inspection signal transmitted from one of the IoT detection modules 300 continues sequentially through the detection line 100 and other IoT detection modules 300. It is relayed to a location where the signal can reach the gateway (not shown) or the MQTT broker 600, and the signal that reaches the gateway or the MQTT broker 600 can be received by the monitoring server 500. There will be a number. Therefore, the present invention can provide a comprehensive monitoring system that detects settlement of all sections of the underground distribution line.

Meanwhile, Figure 14 shows an embodiment in which power can be supplied to the IoT detection module 300 without external power supply. To this end, the present embodiment includes each power module 900 that supplies operating power to each of the pair of IoT detection modules 300, and each of the power modules 900 includes a storage battery 920 and the It is desirable to include a charging circuit 910 that charges the storage battery 920. And the charging circuit 910 connects the power connection line 911 to both ends of the sensing resistor 200, and the both ends voltage applied to both ends of the sensing resistor 200 ( ), it is desirable to operate the charging circuit 910 to charge the storage battery 920. And the storage battery 920 supplies operating power to the IoT detection module 300 through the operating power supply line 930.

In this case, the IoT detection module 300 can operate at all times even if power is not supplied from the outside. However, if the sensing line 100 is disconnected due to the sinking of the conduit 20, further charging of the power module 900 is impossible, so the IoT sensing module 300 requires the storage battery 920. The alarm signal is transmitted at the first time interval until discharge.

Figure 15 shows an embodiment of supplying external power to a closed circuit including the sensing line 100 in the present invention. This embodiment is applicable when the induced current induced in the sensing line 100 is too small for reasons such as the short length of the conduit 20 and the power cable 30 or the low zero phase current. . In this embodiment, power is supplied through a battery or external power source 950 between one end of the sensing line 100 and one of the sensing resistors 200, thereby forcing the circulating current (I) on the closing circuit. By allowing to flow, the both ends voltage ( ) is formed and the IoT detection module 300 monitors it.

Although the present invention has been described with the above-described various examples, the present invention is not necessarily limited to these examples, and may be modified and implemented in various ways without departing from the technical spirit of the present invention. Accordingly, the examples disclosed in the present invention are not intended to limit the technical idea of the present invention but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these examples. The scope of protection of the present invention shall be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope thereof shall be construed as being included in the scope of rights of the present invention.

10 Manhole 15 Sinkhole
20 conduit 30 power cable
31 connection points
100 sensing line 200 sensing resistance
300 IoT detection module
310 Voltage measurement unit 320 Signal generation unit
330 Signal transmitter 331 Antenna
332 connection line 333 coupling condenser
340 Relay signal receiver 343 Coupling condenser
350 control unit
400 grounding means
500 monitoring servers 600 MQTT brokers
700 communication network
900 power module
910 Charging circuit 911 Power connection line
920 storage battery 930 operating power supply line
950 external power

Claims (7)

As a monitoring system to prevent secondary accidents due to sinking of the conduit in an underground distribution line where power cables are laid in conduits buried underground,
A detection wire installed inside the conduit like the power cable, but made of one strand and disconnected when a tensile force exceeding a certain limit is applied;
A pair of sensing resistors connected to both ends of a sensing line installed between two adjacent manholes;
a pair of grounding means connecting one end of each of the pair of sensing resistors opposite to the end connected to the one sensing line and grounding one end of each of the pair of sensing resistors;
It is connected to both ends of the pair of sensing resistors, and detects settlement of the conduit using the both-end voltage, which is the voltage measured at both ends of each sensing resistor. If settlement is determined, an alarm signal containing its identification code is sent. A pair of IoT detection modules that generate and transmit; and
It is possible to receive the alarm signal transmitted by the IoT detection module, and when receiving the alarm signal, the transmission location of the alarm signal is identified using the identification code included in the alarm signal, and the transmission location is included. Includes a monitoring server that generates and displays subsidence information,
Each of the pair of IoT sensing modules,
- A voltage measuring unit that measures the voltage at both ends;
- A signal generator that repeatedly generates the alarm signal at first time intervals when the voltage at both ends falls below a certain value; and
- A signal transmission unit that transmits the warning signal through Internet of Things communication whenever the warning signal is generated;
An underground distribution line monitoring system, characterized in that the resistance value of each of the pair of sensing resistors is greater than the grounding resistance of each of the pair of grounding means. delete According to paragraph 1,
The monitoring server is an underground distribution line monitoring system, characterized in that it generates the subsidence information only when the alarm signal is received from both of the pair of IoT detection modules. According to paragraph 1,
The IoT communication is IoT communication using the MQTT (Message Queuing Telemetry Transport) protocol,
It further includes an MQTT broker that relays the alarm signal,
The IoT detection module transmits the alarm signal to the MQTT broker,
The monitoring server receives the alarm signal through the MQTT broker,
The data format of the alarm signal used in the MQTT protocol is as follows,

- QoS is set to 0,
- LWT (Last Will Testament) is a message containing the meaning that ‘communication has been interrupted due to subsidence.’
- Topic is an underground distribution line monitoring system that combines the hierarchical distribution line name and the identification code of the IoT detection module in the form of feeder line name/main line name/branch line name/branch line name/identification code. According to paragraph 1,
The IoT detection module is divided into a first detection module installed at one end of the one detection line and a second detection module installed at the other end of the one detection line,
Each of the first detection module and the second detection module further includes a relay signal receiver and a control unit,
The signal transmission unit of the first detection module transmits the alarm signal through the one detection line,
The relay signal receiver of the second detection module can receive the alarm signal transmitted by the first detection module through the one detection line,
The signal transmission unit of the second detection module is connected to the relay signal reception unit of the first detection module within the same manhole by a connection line and transmits the alarm signal through the connection line,
The relay signal receiver of the first detection module can receive the alarm signal transmitted by the second detection module through the connection line,
The control unit of the first detection module and the second detection module controls the relay signal reception unit to relay and transmit the alarm signal transmitted by the second detection module or the first detection module through the signal transmission unit. An underground distribution line monitoring system characterized by According to any one of paragraphs 1, 3, 4 or 5,
An underground distribution line monitoring system, characterized in that one point of each end of the one detection line is fixed to the conduit. According to any one of paragraphs 1, 3, 4 or 5,
It further includes: each power module supplying operating power to each of the pair of IoT sensing modules,
Each of the above power modules is
- Storage batteries and
- Includes a charging circuit for charging the storage battery,
- The charging circuit operates with a voltage applied to both ends of the sensing resistor to charge the storage battery.