KR102454187B1 - IoT system for sensing electric arc fire of power line - Google Patents

Abstract

The present invention relates to a powerline arc fire monitoring system. More specifically, powerlines installed in rural areas often pass through densely forested mountainous areas. There is a risk that arc discharges caused by poor contact in powerlines crossing mountainous areas can lead to large fires such as forest fires. The present invention relates to a monitoring system including an IoT sensor module and a monitoring server, which can detect arc discharges occurring at connection points of wires in the powerline and alert a fire risk through an IoT communication network. The IoT sensor module included in the present invention is installed on a processed powerline of a power pole or tower which has a connection part for a jumper wire or a load wire. When a serial arc discharge occurs due to poor contact or wire breakage at the connection part, the module can automatically detect the arc discharge and transmit a fire risk signal through the IoT communication network. Therefore, a manager of the powerline can quickly find and inspect the area where the fire risk signal is generated or the area where a fire is expected. Therefore, the present invention can prevent a fire from spreading and becoming a large scale of fire such as forest fires.

Description

Distribution line arc fire monitoring system {IoT system for sensing electric arc fire of power line}

The present invention relates to a distribution line arc fire monitoring system. Distribution lines often pass through mountainous areas with dense trees. If arc discharge occurs due to poor contact in distribution lines passing through mountainous areas, there is a risk of spreading to large-scale fires such as forest fires. The present invention relates to a monitoring system comprising a plurality of sensor modules and a monitoring server capable of detecting arc discharge when an arc discharge occurs in a connection portion of an electric wire among distribution lines and sending a detection signal through an IoT communication network. The sensor module included in the present invention is a composite sensor module that combines IoT sensors, and is mounted on overhead wires of electric poles or pylons. It can detect and transmit signals through the IoT communication network, and the monitoring server receives the signal and identifies the place where there is a risk of arc fire. Therefore, the manager of the distribution line can quickly find and check the location where a fire occurs or a location where fire risk is expected, and through this, it is possible to prevent the development of a large fire such as a forest fire.

Distribution lines often pass through mountainous areas where trees are dense. In particular, in rural areas, many distribution lines cross mountainous areas or thick forests. When a ground fault or short circuit accident occurs in a distribution line that crosses an area with many trees, such as a mountainous area, overheating or arc discharge may occur due to overcurrent, which may lead to a wildfire. However, in the case of 'parallel arc discharge', which is an arc discharge due to a short circuit accident between the electric lines or a ground fault that occurs due to disconnection of the electric wire itself, the traditional protection developed with high reliability such as a ground fault relay or an overload relay Because the system is activated and the line can be cut off quickly, there are not many cases that lead to actual fire or casualties.

On the other hand, among poles and pylons built on distribution lines, there are 'tension imbalance points' where the tensions on both sides are different. have. In such a tension imbalanced location or long span section, the tension applied to the pylon or pole due to the weight or wind of the overhead wire is very large. It is fixed by pulling the overhead wire with an insulator, and the iron tower or electric pole to which the disabled person is mounted is also called a built-in iron tower or a built-in electric pole. In addition, a built-in iron tower or a built-in electric pole is installed in a place where the horizontal direction of the distribution line is changed by more than a certain angle, or the vertical angle is raised or lowered by more than a certain angle. In addition, electric poles installed with power equipment such as reclosing circuit breakers or pole transformers are often built-in poles, and built-in pylons or built-in poles are also installed at regular spans for stable support of distribution lines. Therefore, at least one or two built-in pylons or built-in electric poles per 10 spans exist in the distribution line.

In a built-in pylon or built-in electric pole, the overhead wire and the obstacle-resistant person are fixed with a clamp to withstand the weight of the overhead wire or the tension caused by the wind. connected through Therefore, severe tension is continuously applied to the part where the overhead wire and the clamp are connected, and as time goes by in the state where the tension is applied, it deteriorates due to fatigue or corrosion caused by the accumulation of vibrations. In one part, poor contact or damage to the wire occurs due to fatigue failure, and in severe cases, it may even result in temporary or intermittent disconnection. In particular, in the case of windy valleys, river crossing sections, or mountain ridges, when wind vibrations occur in overhead wires, the frequency of wind vibrations generated in the wires and the frequencies of wind vibrations generated in connecting wires or down-cut wires are different from each other. For this reason, fatigue is more severe in the areas where wires, clamps, and connecting wires are connected, and wear and deterioration tends to proceed more easily. In other words, in a pylon or electric pole where a person with a disability is installed, wear and damage due to fatigue accumulation, corrosion due to weathering, etc. occur at the connection point between the obstacle-resistant and overhead wire or at the connection point of the connection line called jumper wire, resulting in poor contact or disconnection, etc. In this case, a series arc discharge occurs, which is the same not only in places where people with disabilities are installed, but also in places where there are many connection points of down-duty wires that connect pole power equipment and overhead wires, such as pole transformers or reclosing circuit breakers.

Unlike parallel arc discharge, the series arc discharge is not detected by an overload relay or a ground fault relay, so it is very difficult to detect or prevent it. Therefore, there is a case in which a series arc discharge occurring in a distribution line in a windy and dry season such as springtime leads to a large forest fire, and countermeasures are required. In the case of the forest fire that occurred in Toseong-myeon, Goseong-gun, Gangwon-do in 2019, it was ignited by a series arc discharge that occurred at the connection point of the 22.9kv special high-voltage distribution line, and developed into a very large forest fire that damaged a whopping 1,757ha of forest. Therefore, there is a high need to detect a series arc discharge accident occurring on a distribution line installed in a mountainous area at an early stage and prevent the spread of a forest fire, personal injury, or property damage. The Board of Audit and Inspection also pointed out such a problem (the problem of fire risk due to the connection clamp for the disabled) in the audit report on the safety management of power supply facilities issued in December 2019.

The reason why the arc discharge occurs will be described in more detail with reference to FIG. 1 . Arc discharge refers to a discharge phenomenon in which electricity breaks down insulating layers such as air and flows, generating sparks continuously to generate heat and flame. Arc discharge can be divided into parallel arc discharge and series arc discharge according to the mechanism of its occurrence. As shown in Fig. 1(a), when the wires of each phase are close to each other, such as between phase A and phase B, the parallel arc discharge occurs as the insulation between phases is broken, or when the wire of each phase comes into contact with or close to the ground wire or the ground. This is what happens when the insulation is broken. In other words, parallel arc discharge is a discharge that occurs between wires having a high potential difference, coming into contact with each other in the absence or damaged state, or in the gap between two wires while approaching them too closely. In parallel arc discharge, since the phase-to-phase voltage is directly applied to the arc discharge area, an excessive current flows in the area where the arc discharge occurs. However, in the case of parallel arc discharge, a very large overcurrent is generated in an instant, so it can be detected quickly in a substation or various line protection facilities. damage can be prevented from spreading.

On the other hand, series arc discharge occurs at the incomplete connection of a single conductor, such as poor connection at a connection point or damage to an internal line. That is, as shown in Fig. 1(b), the series arc discharge is an arc discharge generated in a gap formed due to a contact failure or disconnection in one of the wires of each phase. Therefore, the spark or flame generated by the series arc discharge depends on the magnitude of the load current, and is not generated by the potential difference between phases, so it is generated in a smaller size than in the parallel arc discharge. And since it is connected in series with the load, the arc current increases in proportion to the load current, so it is difficult to determine whether an arc discharge has occurred only by understanding the increase or decrease of the current. However, since series arc discharge also causes sparks and flames like parallel arc discharge, there is a possibility that not only power equipment is damaged, but the flame or flame is transferred to surrounding trees or buildings, and it is likely to spread to general fires or wildfires. Nevertheless, there is a problem in that it is difficult to quickly determine whether the occurrence of a series arc discharge occurs at the initial stage of the occurrence of the series arc discharge, as it is rare that it is accompanied by an overcurrent enough to be detected in the power supply stage, such as in a substation.

As such, arc discharge causes fire hazard as well as casualties, so the rapid detection of arc discharge is very important in preventing large-scale accidents such as forest fires. In particular, it is necessary to develop a technology to detect a series arc discharge occurring in a distribution line that cannot be detected by an overcurrent relay or the like. As a conventional method for detecting arc discharge, it is possible to detect the occurrence of a spark by using a light receiving element near a region where arc discharge is likely to occur, or to detect the occurrence of arc discharge by detecting the ripple voltage or the frequency of the arc waveform. There is a method, and there is also a method of detecting and measuring electromagnetic waves emitted during the arc discharge generation process.

However, the method of using a light receiving element is appropriate in a dark indoor such as a substation or a switchboard, but it is difficult to detect the occurrence of a spark outdoors in the presence of sunlight, so it is difficult to use in a transmission line or a distribution line. In addition, the method of detecting arc discharge by analyzing the frequency of the ripple voltage or arc waveform is installed in each supply area or branch circuit to operate a circuit breaker when arc discharge is detected. When arc discharge is detected, it is possible to prevent the spread of arc discharge accidents by blocking the branch line itself, but it becomes impossible to detect the point where the arc discharge occurred among long-distance lines such as transmission lines or distribution lines. That is, the method of detecting and analyzing the frequency of the arc waveform can detect that the arc discharge has occurred at any point in any one line, but it is difficult to detect exactly at which point it occurred, and the There is also the problem that expensive parts are required because analysis and judgment are required.

In the detection method using radiated electromagnetic waves, not only the arrival distance of the radiated electromagnetic waves is short, but also in places where electromagnetic radiation due to other reasons such as lightning, thundercloud or corona discharge occurs, there is a possibility of false detection due to noise caused by them. There are disadvantages. Therefore, it is useful in a closed space such as a switchboard, but it is not suitable for a transmission line or a distribution line installed across a mountainous terrain and a field over a long-distance section. This is because lightning or thunderclouds occur in mountains or fields, and noise due to flashover, reverse flashover, or corona discharge is generated. It is also a very difficult problem to find out where the radiated electromagnetic wave was generated.

Also, there is a method of detecting the occurrence of arc discharge using harmonics. When an arc discharge occurs, harmonics are generated on the wire path. Harmonics generated by arc discharge sometimes flow to the wire of the phase in which the arc discharge occurred, but harmonics generated in each phase flow into the neutral wire to form zero harmonic current. Therefore, it is also possible to determine whether arc discharge has occurred by measuring the third harmonic, which is the zero harmonic current flowing through the neutral wire. However, since harmonics generated in transmission lines or distribution lines are generated by various causes, there is a problem in that it cannot be concluded that the occurrence of harmonics is caused by arc discharge. Therefore, it was difficult to apply the arc discharge detection method through the detection of harmonics.

On the other hand, when wind blows on overhead wires or overhead wires used in distribution lines or transmission lines, wind vibration occurs in which the overhead wire vibrates up and down, and this vibration is called aeolian vibration. Aeolian vibrations are vibrations that always occur when a breeze blows. When a breeze blows within the range of 1 m/s to 7 m/s against an overhead branch or overhead wire, vibration with a frequency of 3 Hz to 150 Hz is generated in the direction perpendicular to the wind direction due to the vortex shedding phenomenon. about cm. These vibrations are called aeolian vibrations. Wind vibrations generated on electric wires and overhead branches in distribution lines or transmission lines can cause damage that negatively affects the reliability or serviceability of electric lines. In other words, if wind vibration continues, fatigue failure occurs in stranded wires used for electric wires and overhead branch wires. In particular, where there is a connection part by clamps, such as a built-in electric pole or a built-in pylon, the possibility of fatigue failure increases.

Fatigue failure due to wind vibration causes damage or partial disconnection of the connection part or connection point of the connecting wire or clamp. This is because, if there is a contact failure or partial disconnection, arc discharge occurs as the contact area touches and falls at the moment of wind vibration. Therefore, it may be possible to consider using wind vibration to determine whether a series arc discharge has occurred. However, it is difficult to use only wind vibration as a means for detecting a series arc discharge because the occurrence of wind vibration does not cause series arc discharge. However, if contact failure occurs, it appears normally normally, but when wind vibration occurs, a series arc discharge occurs. In other words, wind vibration is not only the cause of arc discharge, but also a clue to the discovery. Therefore, in the present invention, arc discharge is determined in consideration of even such a wind vibration phenomenon.

The distribution line arc fire monitoring system according to the present invention, which was created to solve the above problems, is a fire monitoring system that can prevent fires such as forest fires by quickly detecting and notifying when a series arc discharge occurs on a distribution line. intended to provide

Another object of the present invention is to provide a distribution line arc fire monitoring system capable of determining whether a series arc discharge has occurred using electromagnetic waves and wind vibration.

Another object of the present invention is that not only can the monitoring server determine whether a series arc discharge has occurred, but also several It is to provide a distribution line arc fire monitoring system that can identify the overhead wire where arc discharge has occurred among overhead wires of (phase).

Another object of the present invention is that when an arc discharge occurs in a distribution line, it is possible to determine even the occurrence pattern of an arc discharge, such as whether it is a continuous arc discharge, a temporary arc discharge, or an intermittently repeated arc discharge. , to provide a distribution line arc fire monitoring system.

Another object of the present invention is to transmit a signal together with location information measured by GPS when a sensor module mounted on a distribution line transmits a signal, thereby transmitting a signal from a monitoring server that receives a related signal. It is to provide a distribution line arc fire monitoring system that can accurately identify the location and, through this, quickly and accurately find a location with a high risk of fire.

Another object of the present invention is to provide a distribution line arc fire monitoring system that can prevent erroneous detection by filtering when a signal similar to arc discharge is received even though a series arc discharge has not occurred and can increase the reliability of the fire danger signal through this. will provide

Another object of the present invention is to provide a distribution line arc fire monitoring system, which has high durability and low maintenance costs, thereby providing a high economical efficiency by semi-permanently supplying power for operating the sensor module included in the present invention.

Another object of the present invention is to provide a distribution line arc fire monitoring system capable of highly reliable serial arc discharge detection without using expensive components for analyzing arc discharge waveforms.

Another object of the present invention is to automatically detect when the secondary side of the current transformer is opened so that a high voltage is not generated and destroyed or a fire occurs due to the occurrence of high voltage on the secondary side of the current transformer in the sensor module mounted on the distribution line. It is to provide a distribution line arc fire monitoring system with a safety means that can be short-circuited to

Another object of the present invention is to provide a distribution line arc fire monitoring system that can quickly and easily identify the sensor module when it does not operate normally in the monitoring server.

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 of ordinary skill in the art to which the present invention belongs from the description below. There will be.

In order to achieve the above object, the present invention includes a plurality of sensor modules mounted on overhead wires of a distribution line to transmit monitoring results to an IoT communication network and a monitoring server communicating with the plurality of sensor modules, distribution line arc A system for monitoring fire occurrence, each of the plurality of sensor modules comprising: - wind vibration amount measuring means capable of measuring the amount of wind vibration generated in the overhead wire; - Electromagnetic wave measuring means capable of measuring the radiated electromagnetic wave generated during arc discharge; - Communication means for transmitting and receiving data by connecting to the Internet of Things (IoT) communication network; - GPS receiving means capable of measuring the location value and the current time; and - a control means having an identification code for identifying itself; wherein the control means includes: - while accumulating the amount of wind vibration measured by the wind vibration amount measuring means at a first time interval, the first time period ends Each time it occurs, a first signal including a first wind vibration amount that is the accumulated amount of wind vibration for the first time, the identification code, the position value, and the end time of the first time is generated and transmitted through the communication means, - When the measured value is measured higher than the reference value while monitoring the measured value of the electromagnetic wave measured by the electromagnetic wave measuring means, the start time from the first hour before the start time at which the measured value starts to be measured higher than the reference value A second signal including a second wind vibration amount that is the accumulated wind vibration amount up to the time, the identification code, the position value, the measured value, and the start time is generated and transmitted to the monitoring server through the communication means, and the monitoring The server separates and stores the first wind vibration amount included in the first signal for each of the plurality of sensor modules when the first signal is received, - When the second signal is received, the second By comparing the signal with the first signal, it is determined whether arc discharge has occurred, It is preferable to use a distribution line arc fire monitoring system, characterized in that.

The present invention also provides, in addition to the above-described features, when the second signal is received, the monitoring server is, When the included first wind vibration amount is smaller than the second wind vibration amount, it is determined that an arc discharge has occurred at the location where the sensor module that has transmitted the second signal is mounted, When the included end time is the same as the start time, when the first wind vibration amount included in the received first signal received immediately before it is smaller than the second wind vibration amount, the sensor module that transmitted the second signal It is also desirable to set it as a distribution line arc fire monitoring system, characterized in that it is determined that an arc discharge has occurred at the mounted position.

In the present invention, in addition to the above-described features, the control means updates the start time to the current time when the state in which the measured value is higher than the reference value continues for more than a second time after the second signal is transmitted. A second signal is newly generated and transmitted, and is repeatedly transmitted at the second time interval. - When the measured value is measured to be lower than the reference value after transmitting the second signal, the second signal is transmitted last The second signal is repeatedly transmitted for a predetermined time at the second time interval, and after determining that the arc discharge has occurred, the monitoring server, - When repeatedly receiving the second signal that the start time is updated, It is determined as an arc discharge, - If the second signal whose start time is not updated is repeatedly received, it is determined as a one-time arc discharge, - The second signal whose start time is not updated and the start time are updated It is also preferable to use a distribution line arc fire monitoring system, characterized in that when the second signal is alternately received, it is determined as an intermittent arc discharge.

The present invention also further includes, in each of the plurality of sensor modules, a harmonic measuring means for measuring a harmonic current flowing in the overhead wire, in addition to the above-described features, wherein the control means is, - the harmonic measuring means measures By calculating the average value for the first time with respect to the harmonic measurement values of Produced by further including a harmonic measurement value, the monitoring server, - When the first signal is received, the average value included in the first signal is stored separately for each of the plurality of sensor modules, - The arc discharge occurs If it is determined that the harmonic measurement value measured at the start time exceeds a certain range than the average value included in the most recently received first signal among the first signals received from the sensor module that has transmitted the second signal, In this case, it is also preferable to use a distribution line arc fire monitoring system, characterized in that it is determined as an arc discharge generated in the overhead wire of the phase in which the sensor module that has transmitted the second signal is mounted.

The present invention also provides, in addition to the above features, the harmonic measuring means includes: - a current transformer fixed to surround the overhead wire; - a current measuring device connected to both ends of the secondary side of the current transformer to measure a harmonic current; An NTC (Negative Temperature Coefficient) thermistor that is attached to the iron core and makes itself short-circuited by lowering the resistance value when the temperature of the iron core rises, and - to heat the NTC thermistor by generating heat when current flows. a heating resistor attached to the surface, wherein the NTC thermistor and the heating resistor are configured in a series circuit and are connected to both ends of the secondary side of the current transformer, and a disconnection occurs between the secondary side of the current transformer and the current measuring device , When the NTC thermistor is short-circuited due to the temperature rise of the iron core and a current flows in the series circuit, the short circuit state of the NTC thermistor is continuously maintained by the heating of the heating resistor. It is also desirable to set it as a monitoring system.

In addition to the above features, the present invention also includes a dipole antenna in the electromagnetic wave measuring means, and the dipole antenna is a wire of an elastic material protruding from the body of the sensor module in both directions at right angles to the overhead wire. , It is also preferable to use a distribution line arc fire monitoring system, characterized in that inertial masses are respectively fixed to both ends of the dipole antenna, and the wind vibration amount measuring means is included in each of the inertial masses.

As described above, in the distribution line arc fire monitoring system according to the present invention, when the sensor module measures the magnitudes of radiated electromagnetic waves and wind vibrations and transmits them to the monitoring server, the monitoring server detects the changes in wind vibrations at the same time even if the radiation electromagnetic waves are detected. Because it is judged that an arc discharge has occurred only when it does, it is possible to filter out electromagnetic noise that may occur due to various reasons including lightning, thunderclouds, or corona discharge. Therefore, there is an effect of increasing the reliability of arc discharge detection, so even if a 'series arc discharge', which is difficult to detect at the beginning of the occurrence, occurs on the distribution line, the monitoring server can detect it quickly and accurately, and it can prevent a fire. It works.

In the present invention, when the monitoring server determines whether a series arc discharge occurs, the monitoring server can determine whether a series arc discharge occurs on the distribution line because it can determine whether or not there is a change in harmonic current as well as radiation electromagnetic waves and wind vibration. Not only can this be determined more accurately, but there is an effect that the monitoring server can identify the overhead wire where the arc discharge has occurred among the overhead wires of various phases.

The present invention also provides a monitoring server that receives a second signal because the sensor module generates and transmits a second signal including its own position value and wind vibration measured by GPS when a radiation electromagnetic wave is detected on a distribution line It has the effect of quickly identifying the exact location where the arc discharge occurred and notifying the manager, etc.

In addition, only a means for measuring the intensity of electromagnetic waves and a means for measuring the intensity of wind vibration can make a configuration that detects the occurrence of an arc discharge relatively simply, economically and reliably, so that the arc discharge waveform can be analyzed There is an effect that it is possible to provide a sensor module capable of detecting arc discharge with high reliability even without using expensive parts for this purpose.

In addition, since the sensor module normally generates and transmits the first signal including the identification code and the position value at regular time intervals, there is an effect that the monitoring server can quickly and easily identify when the sensor module fails.

In addition, since the first signal sent by the sensor module included in the present invention also includes the amount of wind vibration, the monitoring server that received it measures, compares, and analyzes the accumulated vibration amount due to wind vibration generated in each section of the distribution line. There is an effect of being able to identify in advance the poles that are highly likely to undergo wear or fatigue failure due to fatigue in the near future by using this.

In addition, since the first signal sent by the sensor module included in the present invention may include a harmonic measurement value, it is possible to monitor the harmonic current flowing in the distribution line at all times in the monitoring server, and accordingly, as a zero-phase current flowing in the distribution line It can even achieve the effect of blocking in advance the occurrence of various problems such as overheating of the neutral wire and malfunction of the relay.

In addition, since the sensor module included in the present invention may be equipped with a mass body and a vibration amount measuring means at both ends of the dipole antenna for measuring electromagnetic waves, the sensor module can measure the intensity of wind vibration generated at the corresponding point very easily. Of course, since the dipole antenna and the mass also act as a damper that absorbs vibrations, the sensor module can attenuate vibrations applied to overhead wires at the same time.

In addition, an NTC thermistor is connected to both ends of the secondary side of the current transformer in the sensor module included in the present invention, and the NTC thermistor is operated according to the iron core temperature of the current transformer to be short-circuited. Therefore, when a disconnection occurs between the secondary side of the current transformer and the current measuring device and the magnetic flux of the current transformer increases and overheats, the NTC thermistor is short-circuited to form a closed circuit, preventing the increase in overheating of the iron core, and a high voltage on the secondary side of the current transformer. organic can be prevented. Therefore, even if the secondary side of the current transformer is opened due to a failure of the current measuring device or the band filter, overheating or high voltage is generated so that the sensor module is not destroyed or fire does not occur. Since the present invention has such a structure, it is possible to provide a sensor module with enhanced safety even though the IoT sensor is installed at a very high voltage higher than a special high voltage, and thus a highly reliable sensor module can be provided.

In addition, the NTC thermistor included in the sensor module has a heating resistor connected in series, and when the heating resistor heats up, the NTC thermistor is heated. This heats up and heats the NTC thermistor. Therefore, even if the NTC thermistor is short-circuited and the temperature of the iron core is lowered, the short-circuit state of the NTC thermistor can be continuously maintained because the heating resistor generates heat. If there is no heating resistance, the NTC thermistor is opened when the NTC thermistor is short-circuited and the iron core temperature goes down. Not only can the thermistor fail easily, but there is also a risk that the sensor module may be destroyed or burned due to repeated induced high voltage on the secondary side of the current transformer and repeated overheating of the iron core. Since the heating resistor has a structure that heats the NTC thermistor, the short circuit of the NTC thermistor can be continuously maintained as soon as the current transformer secondary terminal is opened.

In addition, the inside of the sensor module included in the present invention is equipped with a current transformer for measuring harmonic current, and since it includes a power supply means constituting a charging circuit with power supplied through the current transformer, operating power can be supplied semi-permanently, Accordingly, there is an effect that it is possible to provide a sensor module having high durability, low maintenance cost, and high economic feasibility.

In addition, the sensor module included in the present invention has a configuration for repeatedly transmitting the second signal according to the change in the measured value of the radiated electromagnetic wave after transmitting the second signal, and the monitoring server is configured to repeatedly transmit the second signal according to the received second signal. Because it can determine whether the discharge is continuous, one-time, or even intermittent, it has the effect of allowing managers to select and take urgent measures depending on the type of arc discharge.

1 shows a conceptual diagram of generation of a parallel arc discharge (a) and a series arc discharge (b).
Figure 2 shows a pole equipped with a disabled person.
Figure 3 shows an electric pole having a circuit breaker and a person with disabilities.
Figure 4 is a detailed view of the installation site for the disabled.
5 is a block diagram of a distribution line arc fire monitoring system according to the present invention.
6 shows a state in which the sensor module included in the present invention is mounted on a distribution line.
7 is a view showing another state in which the sensor module included in the present invention is mounted on the distribution line.
8 is a close-up view of the sensor module included in the present invention mounted on an electric wire.
9 is an internal configuration diagram of a sensor module included in the present invention.
10 is an internal configuration diagram of an embodiment in which a harmonic measuring means is further included in the sensor module included in the present invention.
11 is a circuit diagram showing a harmonic measuring means of the sensor module included in the present invention.
12 shows a current transformer of the sensor module included in the present invention.
13 is a view for explaining the operating principle of the NTC thermistor and the heating resistor in the harmonic measuring means included in the present invention.
14 is an embodiment in which a mass body is mounted on a sensor module included in the present invention.
15 is an embodiment in which a power supply means connected to a CT is included in the sensor module included in the present invention.

Hereinafter, the present invention will be described in detail so that the above-described objects and features become clear, and accordingly, those skilled in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In addition, in the description of the present invention, if it is determined that the detailed description of the known technology may unnecessarily obscure the gist of the present invention as it is already well known in the technical field among the known technologies related to the present invention, the detailed description thereof is omitted. to be omitted.

In addition, the terms used in the present invention have been selected as widely used general terms as possible, but in certain cases, there are also terms arbitrarily selected by the applicant. It is intended to clarify that the present invention should be understood as the meaning of the term, not the name. Terms used in the description of the embodiments are only used to describe specific embodiments, and are not intended to limit the embodiments. The singular expression includes the plural expression unless the context clearly dictates otherwise.

Embodiments may be modified in various forms and may have various additional embodiments, in which specific embodiments are shown in the drawings and related detailed descriptions are given. However, this is not intended to limit the embodiments to specific forms, and it should be understood to include all changes or equivalents or substitutes included in the spirit and scope of the embodiments.

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

Hereinafter, the present invention will be described with reference to the accompanying drawings. 1 shows a conceptual diagram for a situation in which parallel arc discharge (a) and series arc discharge (b) occur. As described above, in the parallel arc discharge as shown in FIG. 1(a), due to a short circuit or a ground fault between phases, an overcurrent rapidly flows while a high voltage is applied to a short circuit or a ground fault, so that an arc discharge of a considerable size occurs. However, due to such overcurrent, parallel arc discharge is not only quickly detected by various protection systems such as overcurrent protection facilities or ground fault protection facilities, but also the location of short circuits or ground faults in overcurrent protection facilities or systems. Since even the technology has been developed and applied, in the case of parallel arc discharge, it can be taken rather quickly compared to its size and risk.

However, since the series arc discharge as shown in FIG. 1 (b) is a state connected in series to the load, the voltage applied to the gaps at both ends of the discharged wire is small, so the current value that increases due to the arc is not large, and it is a case that proceeds slowly. In many cases, since the normal state and the arc discharge state alternately occur, there has been a problem in that it is difficult to detect this in the protective equipment installed on the power supply side such as a substation. Even if an arc waveform analysis or ripple voltage analysis device is installed in a substation, etc.

The present invention is to solve this problem, and it is mounted on an overhead wire in a place where a series arc discharge is likely to occur among distribution lines and monitors whether an arc discharge occurs, and when a series arc discharge occurs, a related signal including the location It relates to a distribution line arc fire monitoring system that includes a 'multiple sensor module' that generates and transmits and a 'monitoring device' that compares the signals they send to determine whether an arc discharge has occurred and quickly provides the location of the occurrence. Among distribution lines, in electric poles or pylons equipped with disabled persons or poles or pylons installed with pole power equipment, there are many parts where the wires are connected to each other by clamps, connecting wires (jumper wires), and down wires, etc., and fatigue caused by wind vibration, etc. The risk of arc discharge is high because there is a high possibility of abrasion of the connection part and cutting of the wire due to the destruction phenomenon. It is installed to determine whether an arc discharge occurs, and transmits a related signal when an arc discharge occurs, so that the monitoring server can determine this.

2, an electric pole 210 equipped with a disability-resistant 280 is shown among the distribution lines 200, and in FIG. 3, an electric pole 210 having a pole power device such as a reclosing circuit breaker 260 is shown . And, FIG. 4 shows a detailed view of the disabled person 280 mounting portion. The pole 210 or the pylon on which the disabled person 280 is mounted is a 'tension imbalance point' with different tensions on both sides, or a 'long span pole' that is much longer than the standard span due to valleys or rivers, or the horizontal of the distribution line It is a 'pole having an angle' in which the direction is changed by more than a certain angle, or the vertical angle is raised or lowered by more than a certain angle. And, as shown in FIG. 3, the obstacle-resistant person is also mounted on a pole in which a pole power device such as a reclosing circuit breaker is installed.

In a pole 210 or a pylon equipped with a disabled person, since the tension applied to the pylon or pole 210 due to the weight or wind of the overhead wire 220 is large, it can withstand large tension and has an appropriate dip It is fixed by pulling the wire with the handicapped person 280 to maintain it. That is, as shown in FIG. 4, one overhead wire 220a and an obstacle-resistant person 280a are fixed with a clamp 282 to withstand the tension pulled by the weight or wind of the overhead wire 220, and the clamp ( The remaining part of the overhead wire 220a passing through 282 becomes a connection wire 250 (jumper wire), and one end of the connection wire 250 is coupled to the overhead wire 220b connected to the opposite side obstacle resistant 280b. (283), etc. is fastened to connect. Therefore, a state in which severe tension is applied to the portion where the overhead wire 220 and the clamp 282 are connected continues, and the tension is applied to the U-bolt 282a that fastens the clamp 282 to a significant portion. In this state, when wind vibration by wind is generated in the overhead wire 220, the U-bolt 282a fastening portion, the connection portion 255 where the clamp 282 and the connection wire 250 are connected, or the overhead wire 220 and the connection wire Fatigue caused by wind vibration accumulates in the coupling bolts 283 and the like that connect the 250, and in addition to this fatigue phenomenon, corrosion or deterioration that occurs over time is added. , even when tension is applied to the connecting wire 250 due to the relaxation of the U-bolt 282a due to wind vibration. If these phenomena are accumulated, poor contact or disconnection of the wire may occur, and even the connection line 250 may be disconnected.

In particular, in the case of a valley, river crossing section, or ridge area where there is a lot of wind, wind vibration is generated in the overhead wire 220 due to the wind, Since the frequency of the wind vibration generated in the electric wire 270 is different from each other, the overhead wire 220 and the clamp 282, the U-bolt 282a, the overhead wire 220a and the connection part 255 of the connecting wire 250 and the coupling bolt (283) There is a tendency for wear and deterioration to proceed more easily due to the more severe fatigue failure of the fastening parts. Therefore, there is a high possibility that temporary or intermittent disconnection occurs at these connection points or connections.

When a temporary or intermittent disconnection occurs at the connection point or connection part of the overhead wire 220, a series arc discharge occurs. the risk will increase In particular, when an arc discharge occurs in a dry season such as spring in a mountainous area with dense trees, sparks or flame dispersion caused by the arc discharge comes into contact with dry leaves, etc. If a fire occurs due to this, there is a very high possibility that it will develop into a fatal forest fire. Because there are inevitably many built-in electric poles or built-in pylons equipped with disabled persons 280 due to tension imbalances, long span electric poles, etc. A technology capable of quickly detecting arc discharge occurring in the electric pole 210 or the pylon connected to is required.

In addition, as shown in FIG. 3 , in the electric pole 210 in which the pole power device such as the reclosing circuit breaker 260 is installed, the cut-down wire 270 branched from the overhead wire 220 and the COS (Cut Out) connected thereto Switch, 240), a down wire 270 for connecting the COS 240 and the reclosing circuit breaker 260, etc. are connected. , there is a possibility that poor contact may occur at the connection part fastened with screws, etc., and when it is shaken by wind or vibration, the fatigue applied to the down wire 270 causes several strands of the down wire 270 to There is a high possibility that some of the stranded wires will be disconnected. When some strands of the stranded wire constituting the cut-down wire 270 are disconnected, heat is generated, and damage or fatigue fracture caused by heat is aggravated, so that the entire wire is temporarily or intermittently disconnected. In this way, when an air gap is generated due to poor contact or disconnection at the portion where the electric wire 270 and the power device are connected, a series arc discharge phenomenon occurs.

This possibility is the same even in places where switchgear, pole transformer, lightning arrester, power fuse, cable head, circuit breaker or branch line are installed. In a place where such a pole power device is installed, the point where the down-duty wire 270 is connected to the overhead wire 220, the connection part with the power fuse or COS 240, the hot clamp, the screw fastened to the power device connection part, such as a transformer bushing, etc. This is because if it is shaken by wind or vibration, it may become loose, and there is a high possibility of contact failure due to corrosion caused by wind and rain. Therefore, the possibility of a series arc discharge is increased even in a pylon or electric pole 210 in which a pole power device is installed. will rise

As shown in FIG. 5, the distribution line arc fire monitoring system according to the present invention, devised to solve such a problem, is mounted on an overhead line of the distribution line and transmits the monitoring result to the IoT communication network 700. It is preferable to include a 'monitoring server 500' that communicates with the sensor module 100 of 'and the plurality of sensor modules 100 and the Internet of Things (IoT) communication network 700'. And each of the plurality of sensor modules 100 is a location where a series arc discharge is highly likely to occur in the distribution line, that is, an electric pole 210 in which the disabled person 280 is installed or an electric pole 210 in which a pole power device is installed. It is most preferable to be mounted on the electric wire 220 .

6 and 7 show a state in which the sensor module 100 included in the present invention is mounted on the distribution line 200 . As shown in the drawing, the sensor module 100 included in the present invention is preferably mounted on overhead wires of all phases in the case of a three-phase distribution line. In this case, there is an advantage in that it is easy to know which phase of the wire the series arc discharge occurred in by measuring the harmonic current. However, it is also possible to mount only one of the overhead wires 220 .

Meanwhile, FIG. 8 shows an enlarged view of the sensor module 100 included in the present invention mounted on the overhead wire 220 . As will be described later, the sensor module 100 included in the present invention requires a means for measuring wind vibration generated in the overhead wire 220 . Therefore, it is preferable that the sensor module 100 is mounted on the overhead wire 220 for this purpose. And in addition to this, since it is more preferable to measure the harmonic component flowing in the electric wire, it is more preferable to provide a current measuring means and a current transformer (CT) for this so that the harmonic current flowing in the overhead wire 220 can be measured. However, in the case of a current transformer (CT), since it is preferable to be mounted while surrounding the overhead wire 220, as shown in FIG. 8, the body 101 of the sensor module 100 wraps the conductor of the overhead wire 220 and can be fixed. It is preferable to include a fixing clamp (102). And it is preferable that the fixing clamp 102 can be firmly fastened to the overhead wire 220 by the fastening means 103 .

9 shows an internal configuration diagram of the sensor module 100 included in the present invention. As described above, the sensor module 100 included in the present invention is mounted on the overhead wire 220 of the distribution line 200, and the connection part or connection point or cut of the handicapped person 280 installed on the electric pole 210 or the pylon. It is a sensor module 100 that monitors the series arc discharge generated from the electric wire 270 and the like and transmits a fire danger signal. Accordingly, the wind vibration amount measuring means 150 capable of measuring the amount of wind vibration generated in the overhead wire 220, the electromagnetic wave measuring means 120 capable of measuring the radiated electromagnetic waves generated during arc discharge, and the Internet of Things communication network ( 700), the communication means 130 that can transmit and receive data, the GPS receiver 170 that can measure the location value and the current time, and these components can be controlled, and can be identified It is preferable to include a control means 190 having a possible identification code. It is also possible not to have the identification code in the control means 190, but to a UID or the like that the communication means 130 has. In addition, the IoT communication network 700 may use a conventional LPWA (Low Power Wide Area) communication network such as LoRa, but it is also possible to use a communication network such as LTE-M.

In addition, the electromagnetic wave measuring means 120 includes an electromagnetic wave receiving antenna 121 for receiving the radiated electromagnetic waves emitted due to the serial arc discharge, and the communication means 130 includes transmitting and receiving Internet of Things (IoT) communication data. It is preferable to include an IoT antenna 131 for In the case of the electromagnetic wave receiving antenna 121, a directional antenna capable of receiving electromagnetic waves toward the handicap-resistant 280 of the electric pole 210, the connection line 250, so-called jumper wire, the pole power device or the cut-down wire 270, etc. It is more preferable to use a dipole antenna 121 protruding in both directions at right angles to the overhead wire 220 as shown in FIG. 8 for this purpose.

When the series arc discharge phenomenon occurs, it is accompanied by high-frequency pulse current, vibration, light, gas, ultrasonic wave, and radiation electromagnetic wave. Therefore, it is possible to determine whether a series arc discharge has occurred by measuring one of the radiated electromagnetic waves. When a series arc discharge occurs, radiation electromagnetic waves are measured in a very wide band of 30Mhz to 500Mhz, and high electric field strength is shown in a band of 100Mhz to 160Mhz. Therefore, in the present invention, the electromagnetic wave measuring means 120 is provided to measure the radiated electromagnetic wave, and when a radiated electromagnetic wave having a high electric field strength is emitted due to the occurrence of a series arc discharge, it is sensed to determine whether a series arc discharge has occurred. On the other hand, in the case of radiated electromagnetic waves due to series arc discharge, as described above, since the frequency band is very high (microwaves and microwaves), the straightness is high and there is no reflection in the ionosphere. And since the radiation output of the electromagnetic wave by the series arc discharge is not so high, the radiation electromagnetic wave caused by the series arc discharge cannot reach far. Therefore, measurement is possible only in the vicinity or the electromagnetic wave measuring means 120 located in the vicinity.

However, the radiation electromagnetic wave in the distribution line 200 is generated not only in series arc discharge or parallel arc discharge, but also by other causes. For example, it is also generated by lightning or thunderclouds, and radiated electromagnetic waves are also generated by surges or reverse surges caused by lightning strikes, or corona discharges generated when the insulation of the air layer is destroyed by high voltage around the conductor. Therefore, when the electromagnetic wave measuring means 120 receives these radiation electromagnetic waves, there is a risk of erroneous determination as a series arc discharge. Therefore, if the series arc discharge is sensed only with radiated electromagnetic waves in an environment such as a distribution line, the probability of erroneous detection is very high and effectiveness is reduced.

Accordingly, the sensor module 100 included in the present invention further includes the wind vibration amount measuring means 150 in addition to the electromagnetic wave measuring means 120 . If there is a contact defect or a partly disconnected portion of the overhead wire 220, if there is a contact failure or a partly disconnected portion, if the wind vibration occurs even though the current normally flows through contact, the moment when the change in wind vibration occurs or instantaneously due to intermittent wind vibration A series arc discharge occurs as the contact part touches and falls. In other words, wind vibration is not only a cause of arc discharge as described above, but also a clue to the discovery of arc discharge. Therefore, in the present invention, the arc discharge is determined in consideration of such a wind vibration phenomenon.

In the present invention, when a contact defect or a fatigue fracture site occurs, the normal state is normally maintained, but when wind vibration occurs, a series arc discharge occurs due to the wind vibration, and wind vibration is used for arc discharge monitoring. did. However, since the occurrence of wind vibration does not mean that series arc discharge occurs, only wind vibration cannot be used as a means for detecting series arc discharge. Therefore, in the sensor module 100 according to the present invention, the series arc discharge is generated by using the wind vibration amount measured by the wind vibration amount measuring means 150 together with the electromagnetic wave measurement result measured by the electromagnetic wave measuring means 120 . was able to accurately determine whether That is, when an increase in the amount of wind vibration is sensed at the moment when the electromagnetic wave measuring means 120 detects the electromagnetic wave, it is determined that a series arc discharge occurs.

To this end, first, the control means 190 accumulates the amount of wind vibration measured by the wind vibration amount measuring means 150 at first time intervals, and whenever the first time ends, the wind vibration for the first time period is accumulated. Preferably, the first signal including the accumulated first wind vibration amount, the identification code, the position value, and the end time of the first time is generated and transmitted through the communication means 130 . As the end time, it is preferable to use the current time measured by the GPS receiving means 170 . Here, it is preferable that the first time period be short, for example, 5 seconds or 10 seconds. However, it is possible to make relatively long distances in tens of seconds or minutes. It is also preferable that the wind vibration amount measuring means 150 is a vibration generator. That is, the amount of power generated during the first time (wh) by the vibration generator is the amount of wind vibration for the first time.

The first signal is also a signal including data used when the monitoring server 500 determines the occurrence of an arc discharge, but a signal notifying the monitoring server 500 whether the sensor module 100 is operating normally. It is also Accordingly, the monitoring server 500 can determine whether the sensor module 100 is operating normally by receiving the first signal. Since the first signal includes the identification code and the position value, the monitoring server 500 can identify the operation signal transmitted from the sensor module 100 installed in which position.

And since the first signal includes a first wind vibration amount, which is the accumulated amount of wind vibration for the first time, the monitoring server 500 calculates the accumulated wind vibration amount collected by each of the sensor modules 100. It is possible to know for each of the plurality of sensor modules. Accordingly, the managers of the distribution line 200 can identify a location where a lot of fatigue due to wind vibration is accumulated while monitoring the distribution status of the wind vibration of the distribution line 200 through the monitoring server 500 . , it is possible to identify a location where fatigue failure due to wind vibration is likely to occur in the near future among the distribution lines 200 , and by using this, the distribution line 200 can be maintained in a timely manner.

And the control means 190, when the measured value is measured higher than the reference value while monitoring the radiation electromagnetic wave measurement value measured by the electromagnetic wave measuring means 120, the measured value starts to be measured higher than the reference value The communication means by generating a second signal including a second wind vibration amount that is the accumulated wind vibration amount from the first time to the start time based on the time, the identification code, the position value, the measured value, and the start time It is preferable to transmit to the monitoring server 500 through That is, by measuring the amount of wind vibration when the radiated electromagnetic wave increases and providing it to the monitoring server 500, the monitoring server 500 can determine whether there is a difference from when the radiated electromagnetic wave is not measured. to be.

Here, the 'reference value' compared with the measured value of the radiated electromagnetic wave takes into account the measurement level of the radiated electromagnetic wave that can be normally received and the radiated electromagnetic wave noise generated by corona discharge, etc., from the sensor module 100 to the It is preferable to set the minimum value that can be measured when a series arc discharge actually occurs in consideration of the distance to the disabled person 280, the connection line 250, the pole power device, or the down-duty wire 270. In addition, it is also preferable to limit the measured value of the radiated electromagnetic wave measured by the electromagnetic wave measuring means 120 to a value measured in a specific frequency band. For example, if it is limited to a band of 100Mhz to 160Mhz that can represent a high electric field strength among the radiated electromagnetic waves of the series arc discharge, it will be a method to increase the precision of measurement and reduce the manufacturing cost.

In addition, when the first signal is received, it is preferable that the monitoring server 500 divides and stores the first wind vibration amount included in the first signal for each of the plurality of sensor modules 100 . In addition, the monitoring server 500, when the second signal is received, compares the second signal with the first signal to determine whether an arc discharge occurs, and when it is determined that the arc discharge occurs, the second signal It is preferable to identify and express the location where the sensor module 100 that has transmitted the 2 signals is mounted as a fire risk location.

To this end, the monitoring server 500, when the second signal is received, is included in the most recently received first signal among the first signals sent by the sensor module 100 that has transmitted the second signal. When the first wind vibration amount is smaller than the second wind vibration amount, it is preferable to determine that the arc discharge has occurred at the position where the sensor module 100 that has transmitted the second signal is mounted. However, when the end time included in the most recently received first signal is the same as the start time, in this case, the second wind vibration amount and the same section as the first wind vibration amount are measured. can't Therefore, in this case, when the first wind vibration amount included in the received first signal received immediately before that is smaller than the second wind vibration amount, the arc discharge occurs at the position where the sensor module that transmitted the second signal is mounted. It is preferable to judge that it has occurred.

Even in a state where intermittent or temporary disconnection occurs due to fatigue failure occurring at the connection point or connection part of the electric wire, arc discharge does not normally occur. As a result, arc discharge occurs. In particular, when the magnitude of wind vibration changes, the separation distance or contact resistance changes. Therefore, in the present invention, when a radiation electromagnetic wave is observed at a specific location and an increase in wind vibration is sensed at the location, it is determined that an arc discharge occurs. That is, in the present invention, if the measured value of the radiated electromagnetic wave is in a state in which wind vibration increases at the moment it is observed, it is determined that an arc discharge has occurred. It is not a series arc discharge, but an electromagnetic wave received by other factors.

On the other hand, in the present invention, it has a configuration that can distinguish and determine whether the arc discharge is continuously occurring, is in a state that has occurred temporarily and is stopped, or is in a state that occurs intermittently and repeatedly. To this end, when the state in which the measured value is higher than the reference value continues for more than a second time even after transmitting the second signal, the control means 190 renews a second signal that has updated the start time to the current time. It is preferable to generate and transmit, but to transmit repeatedly at the second time interval. Here, the second time is preferably set to a very short time, such as 0,5 seconds, 1 second, or 2 seconds. That is, when the arc discharge continues to occur, only the time information is changed and the second signal is continuously transmitted. And, when the measured value is lower than the reference value after transmitting the second signal, since the arc discharge is stopped, the last second signal among the second signals is transmitted for a predetermined time at the second time interval. It is preferable to transmit repeatedly during the period.

And the monitoring server 500, after determining that the arc discharge has occurred, when repeatedly receiving the second signal that the start time is updated, it is determined as a continuous arc discharge, and the start time is not updated. When the two signals are repeatedly received, it is determined as a one-time arc discharge, and when the second signal whose start time is not updated and the second signal whose start time is updated are alternately received, it is determined as an intermittent arc discharge It is preferable to do so. As such, the present invention has the advantage of being able to discriminate and discriminate even the form of arc discharge. Therefore, the monitoring server 500 can inform the administrator, etc. whether the arc discharge is continuously occurring, is in a state that has occurred temporarily and is stopped, or is in a state that occurs repeatedly intermittently.

On the other hand, as shown in FIG. 10, the sensor module 100 included in the present invention may further include a harmonic measuring means 110 for measuring a harmonic current flowing in the overhead wire 220. When a series arc discharge occurs in the overhead wire 220, harmonics are generated, and in general, the content of the third harmonic component in addition to the fundamental is the highest. The third harmonic flows through the overhead wire 220 of the phase in which the series arc discharge occurs, and the third harmonic generated in each phase flows into the overhead neutral wire 221 to form a zero-phase current. Therefore, in the sensor module 100 according to the present invention, the harmonic measuring means 110 measured together with the measurement result of the electromagnetic wave measured by the electromagnetic wave measuring means 120 and the measurement result of the wind vibration amount measuring means 150 Harmonic measurement results were also used to more accurately determine whether a series arc discharge occurred. Theoretically, by measuring the third harmonic component flowing through the overhead wire, it is possible to determine whether a series arc discharge has occurred. However, since harmonic components are generated by various causes in the distribution line, it is impossible to determine whether a series arc discharge has occurred only by measuring the harmonics. Therefore, in the present invention, the result values for three types of electromagnetic waves measured by the electromagnetic wave measuring means 120, wind vibration measured by the wind vibration amount measuring means 150, and harmonics measured by the harmonic measuring means 110 are obtained. In summary, the occurrence of series arc discharge is judged, and reliable results can be obtained through this.

For this purpose, it is preferable that the control means 190 calculates an average value for the first time with respect to the harmonic measurement values measured by the harmonic measurement means 190 . And when the control means 190 generates the first signal, the average value for the first time for the harmonic measurement value in addition to the first wind vibration amount, the identification code, the position value, and the end time It is preferable to include more to generate. In this case, the monitoring server 500 receives the first signal, and not only can check whether the sensor modules 100 are operating normally, but also monitor the third harmonic value flowing through the distribution line 200 at all times. Since it can be monitored, it has a means for monitoring the zero-phase current flowing in the neutral line of the distribution line 200 .

In addition, when generating the second signal, it is preferable that the control means 190 further includes a harmonic measurement value measured at the start time. That is, when the measured value of the radiated electromagnetic wave is higher than the reference value, the measured value of harmonics at that moment (the start time) is measured, and the second signal includes the second wind vibration amount, the identification code, the position value, the In addition to the measurement value and the start time, the harmonic measurement value of the start time is further included to generate and transmit.

In addition, when the first signal is received, the monitoring server 500 divides and stores the average value (average harmonic measurement for the first time) included in the first signal for each of the plurality of sensor modules. desirable. And, when it is determined that the arc discharge occurs by using the first signal and the second signal, the harmonic measurement value measured at the start time is the first received from the sensor module 100 that transmitted the second signal. When it exceeds a certain range than the average value included in the most recently received first signal among the signals, arc discharge generated in the overhead wire of the phase in which the sensor module 100 that has transmitted the second signal is mounted. It is preferable to judge as For this purpose, it is more preferable that the monitoring server 500 has a table that can identify which phase the overhead wire 220 is mounted on for each identification code of the sensor module 100 .

Since the present invention has such a configuration, the amount of wind vibration is measured while the electromagnetic wave is measured, and when the harmonics increase, it is determined that a series arc discharge has occurred, so the monitoring server 500 is the sensor module 100. Using these transmitted signals, it is possible to make a more accurate judgment as to whether a series arc discharge has occurred, thereby increasing the reliability of the fire hazard identification result and enhancing the fire prevention effect.

In addition, as shown in FIGS. 6 and 7 , when the sensor module 100 is mounted on each phase of the overhead wire 220, when a series arc discharge occurs, only the phase in which the arc discharge occurs is converted to arc current. Since the increase in harmonic current will appear, it is possible to easily identify the overhead wire 220 where the arc discharge has occurred among the three overhead wires 220, and after receiving the resulting fire danger signal, the processing of the corresponding phase during on-site inspection Since the wire 220 can be looked at particularly closely, there is an effect of quickly discovering the overhead wire in which the arc discharge has occurred.

And, as described above, it is also possible to mount only one sensor module 100 instead of three for each pole. In this case, it is preferable to alternately install the A, B, and C phases for each electric pole 210 . 5, for example, 100a is mounted on the overhead wire 220 of the A phase, 100b is mounted on the overhead wire 220 of the B phase, 100c is mounted on the overhead wire 220 of the C phase, 100d is to be mounted on the overhead wire 220 of the A phase again. In this case, it is not the same as having the sensor module 100 mounted on all of the three-phase overhead wires 220 in the electric pole 210 of one location, but a similar effect can be seen. For example, when mounting while changing the phase in this way, the monitoring server 500 receiving the second signal requests to send the harmonic measurement value measured at the start time to all of the plurality of sensor modules 100 . Preferably, the phase in which the arc discharge occurred can be confirmed by using the harmonic measurement values sent from each of the plurality of sensor modules 100 . To this end, it is preferable that the monitoring server 500 has identification code information for each of the plurality of sensor modules 100 and information on a phase mounted for each identification code.

On the other hand, "when the harmonic measurement value measured at the start time exceeds a certain range than the average value of the most recently received first signal among the average values included in the first signal" means 'radiation electromagnetic wave measurement value The harmonic measurement value at the moment of measurement higher than this reference value is higher than the “average value for the first time period for the harmonic measurement values” included in the first signal received immediately before that value within a certain range - for example It means that the effective value of the third harmonic current is set to a value that is 10% or more higher than the previous value. Here, the immediately preceding value may be an average value of the first signal received immediately before, but may also be an average value of several previously received average values.

Meanwhile, a configuration diagram of the harmonic measuring means 110 included in the sensor module 100 is shown in the lower right of FIG. 10 , and a circuit diagram of the harmonic measuring means 110 is shown in FIG. 11 . And FIG. 12 shows the internal and external structures of the current transformer 111 included in the harmonic measuring means 110 . Hereinafter, a detailed configuration of the harmonic measuring means 110 included in the present invention will be described with reference to FIGS. 10 to 12 . As shown in FIGS. 10 and 11 , the harmonic measuring means 110 is connected to both ends of the secondary side of the current transformer 111 fixed to surround the overhead wire 220 and the current transformer 111 to measure the harmonic current. An NTC (Negative Temperature Coefficient) thermistor 114 that is attached to the iron core 111a of the current transformer 111 and lowers the resistance value when the temperature of the iron core 111a rises and makes itself short-circuited. ) and a heating resistor 115 attached to the outer surface of the NTC thermistor 114 to heat the NTC thermistor 114 by generating heat when a current flows.

In addition, the NTC thermistor 114 and the heating resistor 115 are configured in a series circuit and connected to both ends of the secondary side of the current transformer 111 , so that between the secondary side of the current transformer 111 and the current measuring device 113 . When a disconnection occurs in the NTC thermistor 114 due to the temperature rise of the iron core 111a, when a current flows in the series circuit, the NTC thermistor 114 is heated by the heating resistor 115. It is desirable to keep the short circuit state of In addition, since the harmonic current is preferably set to the third harmonic, a band filter 112 is provided between the current measuring device 113 and the current transformer 111 so that the current measuring device 113 can measure only the third harmonic. ) is preferably included.

As shown in FIG. 12 , the current transformers 111 and CT are preferably formed of an annular iron core 111a surrounding the conductor 221 of the electric wire and a secondary winding 111b wound around the iron core 111a. In this way, the primary side of the current transformer 111 (CT) becomes the conductor 221 of the electric wire, and the secondary side becomes the secondary winding 111b wound around the iron core 111a, thereby connecting the conductor 221 of the electric wire. The current flowing through the secondary winding 111b is lowered at a constant rate to flow through both ends. The iron core 111a constituting the current transformer 111 is connected to the body 101 of the sensor module 100 and positioned inside the fixing clamp 102 surrounding the conductor 221, so that the fixing clamp ( 102) is spread and wrapped around the conductor 221 of the electric wire, the iron core 111a surrounds the conductor 221, and the current induced through the iron core 111a and the secondary winding 111b It flows to the band filter 112 and the current meter 113 . The iron core 111a is opened when the fixing clamp 102 is opened, and when the fixing clamp 102 is tightened and combined, the annular shape can be completed, as shown in FIG. It is also preferable to combine the semi-annular iron cores to form a single annular iron core 111a.

Meanwhile, FIG. 13 is a view for explaining the operating principle of the NTC thermistor 114 and the heating resistor 115 in the harmonic measuring means 110 included in the sensor module according to the present invention. In the case of the current transformer 111, when the secondary side is opened, the magnetic flux of the iron core 111a constituting the current transformer 111 is rapidly increased, so that a high voltage is applied to the secondary side of the current transformer 111, and the iron core 111a Overheating occurs due to magnetic saturation. Therefore, when the part A connected to the current measuring device is disconnected and the secondary side of the current transformer 111 is in an open state, the sensor module 100 may be burned and a local flame may occur. However, the sensor module 100 according to the present invention includes the NTC thermistor 114 and the heating resistor 115 configured as a series circuit as a means to prevent this. The NTC thermistor 140 is an element whose resistance value decreases when the temperature rises. And the NTC thermistor 140 is attached to the iron core 111a of the current transformer 111 so as to operate according to the temperature of the iron core 111a constituting the current transformer 111, so that the temperature of the current transformer 111 is When it rises, the resistance value goes down and it is a configuration in which it is short circuited by itself.

In the present invention, as shown in FIGS. 10 and 11 , the NTC thermistor 114 and the heating resistor 115 are configured in a series circuit and are connected to both ends of the secondary side of the current transformer 111 . Therefore, when a disconnection A occurs between the secondary side of the current transformer 111 and the current measuring device 113, the temperature of the iron core 111a increases, and the heat h1 generated from the iron core 111a. ) is applied to the NTC thermistor 114, and when the temperature of the NTC thermistor 114 is increased by the heat h1 generated in the iron core 111a, the NTC thermistor 114 is short-circuited or in a conduction state. becomes When the NTC thermistor 114 conducts or is short-circuited, a current flows in the series circuit, so that the heating resistor 115 generates heat h2 to heat the NTC thermistor 114 . Therefore, even if the heat h1 generated from the iron core disappears according to the short circuit of the NTC thermistor 114, the conduction or short circuit of the NTC thermistor 114 continues due to the heat h2 of the heating resistor 115. maintain.

If only the NTC thermistor 114 is used without the heating resistor 115, the NTC thermistor 114 is short-circuited by the heat h1 generated from the iron core, and when the NTC thermistor 114 is short-circuited, the iron core Since the heat h1 is removed from the NTC thermistor 114 is again in the open state, and when the NTC thermistor 114 is in the open state, the iron core is heated. There is a risk that the function of the NTC thermistor 114 is lost in an instant. However, in the present invention, since the NTC thermistor 114 and the heating resistor 115 are configured in a series circuit, there is no risk of this, and from the moment the secondary side of the current transformer 111 is opened, the NTC thermistor 114 conducts or Since the short-circuit condition can be continuously maintained, there is no risk of failure or secondary accident.

And when the NTC thermistor 114 short-circuits both ends of the secondary side of the current transformer 111, the control means 190 generates a fault signal including the identification code and then through the communication means 130 It is preferable to transmit the data to the IoT communication network 700 . The control means 190 determines whether the current flowing through the current meter 113 is suddenly changed to zero or a very low current value, measures the current value flowing through the NTC thermistor 114, or the NTC thermistor ( 114) It is possible to know whether the series circuit has short-circuited both ends of the secondary side of the current transformer 111 due to the method of measuring the voltage across both ends, the heating state of the heating resistor 115 or the iron core 111a, and the like. The monitoring server 500, which has received the failure signal through the IoT communication network 700, identifies the location where the sensor module 100 that transmits the failure signal with the identification code included in the failure signal is mounted, and , it can be notified to the manager, etc., so that the necessary action can be taken.

On the other hand, the band filter 112 is connected to both ends of the secondary winding 111b wound around the iron core 111a which is the secondary side of the current transformer 111, It is a configuration that filters out only the harmonic, preferably the third harmonic component. Therefore, the bandpass filter 112 is a bandpass filter that passes only the frequency band of 180hz so that all of the fundamental wave and other harmonic components among the currents transformed by the current transformer 111 can pass and only the third harmonic component can pass. It is preferable to do Since the band filter 112 passes only the third harmonic component, the value measured by the current measuring device 113 may be the effective value of the current of the third harmonic. It is more preferable to transmit the value measured by the current meter 113 to the control means 190 . As such, the present invention can implement the harmonic measuring means 110 for measuring only the third harmonic component with a simple configuration of the CT 111, the band filter 112, and the current measuring instrument 113, so the number of parts is small, so durability There is an effect that can provide this high and economical sensor module (100).

14 shows another embodiment of the present invention. This embodiment is an embodiment applicable to a case in which a dipole antenna is employed in the electromagnetic wave receiving antenna 121 included in the electromagnetic wave measuring means 120 . In this embodiment, the dipole antenna 121 is preferably a wire made of an elastic material protruding from the main body 101 of the sensor module 100 to both sides at right angles to the overhead wire 220 . It is preferable that inertial masses 171 are respectively fixed to both ends of the dipole antenna 121 , and the wind vibration amount measuring means 150 is included in each of the inertial masses 171 . In this case, when wind vibration occurs in the overhead wire 220, the dipole antenna 121 serves as a messenger cable, and an inertial mass 171 at both ends of the dipole antenna 121 vibrates while the overhead wire ( 220), so that the sensor module 100 can also serve as a damper for absorbing wind vibration of the overhead wire 220. In addition, since the wind vibration amount measuring means 150 is included in each of the inertial masses 171, the amount of vibration is increased, so it is easier to measure the amount of vibration energy, and since it can act sensitively to the change amount, the wind vibration amount There is also an effect of increasing the measurement accuracy of the measuring means 150 .

15 shows another embodiment of the present invention. As shown in FIG. 15, between the current transformer 111 and the band filter 112, a power supply means 180 capable of supplying power required for operation of each component (communication unit, control unit, etc.) of the sensor module 100. It is more preferable to connect It is preferable that the power supply means 180 includes a storage battery (not shown) that can be charged with the current supplied from the current transformer 111 and a charging circuit (not shown) for this. In this configuration, the power required for the operation of the sensor module 100 can be used semi-permanently.

Although the present invention has been described with the various examples described above, the present invention is not necessarily limited to these examples, and various modifications may be made within the scope without departing from the technical spirit of the present invention. Therefore, the examples disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these examples. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100 sensor module
101 Body 102 Fixing Clamp
103 Fastening means 110 Harmonic measuring means
111 current transformer 111a iron core
111b secondary winding 112 bandpass filter
113 Current Meter 114 NTC Thermistor
115 Heating resistance 120 Electromagnetic wave measuring means
121 electromagnetic wave receiving antenna 130 communication means
131 IoT antenna 150 Wind vibration measurement means
170 GPS receiving means 171 Inertial mass
180 power supply means
190 Control means
200 distribution lines
210 Jeonju 220 overhead wire
221 overhead neutral
240 COS 250 connection wire (jumper wire)
255 Connection part 260 Reclosing circuit breaker
270 Inha wire 290 Wanggeum
280 Disabled person 282 Clamp
282a U bolt 283 coupling bolt
500 monitoring server
700 Internet of Things Network

Claims (6)

A system for monitoring the occurrence of an arc fire in a distribution line, comprising a plurality of sensor modules mounted on overhead wires of a distribution line and transmitting a monitoring result to an Internet of Things communication network, and a monitoring server communicating with the plurality of sensor modules,
Each of the plurality of sensor modules,
- wind vibration amount measuring means capable of measuring the amount of wind vibration generated in the overhead wire;
- Electromagnetic wave measuring means capable of measuring the radiated electromagnetic wave generated during arc discharge;
- Communication means for transmitting and receiving data by connecting to the Internet of Things (IoT) communication network;
- GPS receiving means capable of measuring the location value and the current time; and
- Control means having an identification code that can identify itself; includes;
The control means,
- While accumulating the amount of wind vibration measured by the wind vibration amount measuring means at first time intervals, whenever the first time ends, the first wind vibration amount that is the accumulated amount of wind vibration for the first time, the identification code, and the location A first signal including a value and the end time of the first time is generated and transmitted through the communication means,
- When the measured value is measured higher than the reference value while monitoring the measured value of the electromagnetic wave measured by the electromagnetic wave measuring means, the start time from the first hour before the start time at which the measured value starts to be measured higher than the reference value A second signal including a second wind vibration amount that is the accumulated wind vibration amount up to the time, the identification code, the position value, the measured value, and the start time is generated and transmitted to the monitoring server through the communication means,
The monitoring server,
- When the first signal is received, the first wind vibration amount included in the first signal is stored separately for each of the plurality of sensor modules,
- When the second signal is received, the second signal is compared with the first signal to determine whether an arc discharge has occurred,
- Distribution line arc fire monitoring system, characterized in that when it is determined that the arc discharge has occurred, the location where the sensor module that has transmitted the second signal is mounted is identified as a fire risk location and displayed According to claim 1,
When the second signal is received, the monitoring server,
- When the first wind vibration amount included in the most recently received first signal among the first signals sent by the sensor module that has transmitted the second signal is smaller than the second wind vibration amount, the second signal is transmitted It is judged that arc discharge has occurred at the location where the sensor module is installed,
- When the end time included in the most recently received first signal is the same as the start time, when the first wind vibration amount included in the received first signal immediately before that is smaller than the second wind vibration amount , A distribution line arc fire monitoring system, characterized in that it is determined that an arc discharge has occurred at a location where the sensor module that has transmitted the second signal is mounted According to claim 1,
The control means
- If the state in which the measured value is higher than the reference value continues for more than a second time even after transmitting the second signal, a second signal updated by updating the start time to the current time is newly generated and transmitted, but the second time Repeatedly sending at intervals,
- If the measured value is measured to be lower than the reference value after transmitting the second signal, the second signal transmitted last among the second signals is repeatedly transmitted for a predetermined time at the second time interval,
After determining that the arc discharge has occurred, the monitoring server,
- In the case of repeatedly receiving the second signal in which the start time is updated, it is determined as a continuous arc discharge,
- In the case of repeatedly receiving the second signal for which the start time is not updated, it is determined as a one-time arc discharge,
- Distribution line arc fire monitoring system, characterized in that it is determined as an intermittent arc discharge when the second signal whose start time is not updated and the second signal whose start time is updated are alternately received According to claim 1,
In each of the plurality of sensor modules, a harmonic measuring means for measuring a harmonic current flowing in the overhead wire; further comprising,
The control means,
- When generating the first signal by calculating the average value for the first time with respect to the harmonic measurement value measured by the harmonic measurement means, it is generated including the average value,
- When generating the second signal, it is generated by further including the harmonic measurement value measured at the start time,
The monitoring server,
- When the first signal is received, the average value included in the first signal is stored separately for each of the plurality of sensor modules,
- When it is determined that the arc discharge has occurred, the harmonic measurement value measured at the start time is higher than the average value included in the most recently received first signal among the first signals received from the sensor module that transmitted the second signal. Distribution line arc fire monitoring system, characterized in that when it exceeds a certain range, it is determined as an arc discharge generated in the overhead wire of the phase in which the sensor module that has transmitted the second signal is mounted. 5. The method of claim 4,
The harmonic measurement means,
- a current transformer that surrounds the overhead wire and is fixed;
- A current measuring device connected to both ends of the secondary side of the current transformer to measure the harmonic current;
- A Negative Temperature Coefficient (NTC) thermistor that is attached to the iron core of the current transformer and makes itself short-circuited by lowering the resistance value when the temperature of the iron core rises; and
- A heating resistor attached to the outer surface of the NTC thermistor to heat the NTC thermistor by generating heat when current flows,
- The NTC thermistor and the heating resistor are configured in a series circuit and are connected to both ends of the secondary side of the current transformer. Distribution line arc fire monitoring system, characterized in that when the thermistor is short-circuited and current flows in the series circuit, the short-circuit state of the NTC thermistor is continuously maintained by the heating of the heating resistor. According to claim 1,
The electromagnetic wave measuring means includes a dipole antenna,
The dipole antenna is made of a wire of an elastic material protruding from the body of the sensor module in both directions at right angles to the overhead wire,
An inertial mass is fixed to both ends of the dipole antenna,
The wind vibration amount measuring means is characterized in that included in each of the inertial mass, distribution line arc fire monitoring system

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