KR102254312B1 - streetlight portal operating system based on bigdata and AI - Google Patents

Abstract

The present invention relates to a street light and, more particularly, to a technology for integrating and operating a plurality of street light sites based on big data and artificial intelligence (AI). A street light portal operating system based on big data and AI according to a preferred embodiment of the present invention includes: a big data part for collecting the total current from at least one street light distribution network in real time; and an AI part for using the total current on the big data part to determine an abnormality in the street light distribution network. It is possible to determine whether there is an abnormality in the streetlight distribution network and at the same time identify the cause of the abnormality.

Description

Streetlight portal operating system based on bigdata and AI}

The present invention relates to a streetlight, and more particularly, to a technology for integrated operation of a plurality of streetlight sites based on big data and artificial intelligence (AI).

Street lights can be turned on and off using commercial power. At this time, in order to supply commercial power to the street light, a street light distribution board may be installed. The street light distribution board can receive commercial power through the main power line and supply it to the street light through the branch power line.

At least one street light may be connected to the single branch power line. When a plurality of street lights are installed, a plurality of street lights may be installed in parallel on a single branch power line.

Currently, streetlight maintenance is performed in the form of on-site inspection when an abnormality occurs after installation. This maintenance method can generate frequent complaints. And, such a maintenance method can lower the reliability of the infrastructure of a national or local government.

As a related technology, there is Korean Patent Registration No. 10-0833683. Korean Patent Registration No. 10-0833683 relates to a daytime monitoring system using ZigBee communication, and is characterized by monitoring a line using a safety voltage and transmitting the monitoring result through a ZigBee communication method. In addition, Korean Patent Registration No. 10-0833683 is characterized in that the deungju control monitor uses a battery as an emergency power source.

In monitoring the streetlight distribution network, the existing technology only determined whether there was an abnormality in the streetlight distribution network, and it was not possible to clarify the cause of the abnormality. Accordingly, when an abnormality occurs, there is a problem that additional cost and manpower consumption are required for determining the cause of the abnormality. In addition, there is a problem that excessive and unnecessary maintenance costs are generated when the exact cause of the abnormality cannot be determined.

together. In the past, only passive measures have been taken to repair when an abnormality occurs in the streetlight distribution network.

1. Korean Patent Registration No. 10-0833683 (Name of invention: Dungju weekly monitoring system using Zigbee communication)

An object of the present invention is to provide a big data and AI-based street light portal operating system capable of determining whether or not an abnormality in a streetlight distribution network is present and at the same time identifying the cause of the abnormality.

In addition, it is an object of the present invention to provide a big data and AI-based street light portal operating system capable of determining the number of street lights failure and the location of the failure when a street light failure occurs.

In addition, an object of the present invention is to provide a big data and AI-based street light portal operating system capable of monitoring signs of abnormality before an abnormality occurs in a streetlight distribution network.

Big data and AI-based street light portal operating system according to an embodiment of the present invention includes a big data unit for collecting the total current from at least one street light distribution network in real time; And an AI unit that uses the total current on the big data unit to determine signs of abnormalities in the streetlight distribution network.

Here, the AI unit may determine an abnormal symptom using a street light failure probability, a short circuit rate, and a ground fault rate.

And, the probability of failure of the street light is the following equation

[Equation]

here,

i: Total current flowing through the branch power line in response to the safety voltage for each branch power line measured by the measuring unit

in: Total current flowing through the branch power line in response to the safety voltage in a normal state

iz: Attenuation of the total current of the branch power line in response to a failure of a street light that causes the streetlight failure event with the smallest attenuation of the total current of the branch power line among street lights connected to the branch power line.

Can be calculated by

In addition, the ground fault rate is the following equation

[Equation]

Can be calculated by

In addition, the short circuit rate is the following equation

[Equation]

Can be calculated by

In the present invention, it is possible to determine the cause of the abnormality while determining whether or not the streetlight distribution network is abnormal by using a safety voltage.

In addition, the present invention can determine the number of failures and the location of the failure in the case of a failure of the street light.

According to the present invention, as information on indications of an abnormality in a streetlight distribution network, by providing a streetlight failure probability, a ground fault rate, and a short circuit rate, it is possible to smoothly proceed with maintenance and repair work before occurrence of a streetlight distribution network abnormality.

1 is a schematic diagram of an operating system according to a preferred embodiment of the present invention.
Figure 2 is a functional block diagram of the operating system of Figure 1;
3 is a schematic diagram of a second branch power line in FIG. 2.
4 is a circuit diagram of FIG. 3.
5 is a reference value table for determining the type of abnormality.
6 is a table specifying the number of streetlight failures and current values according to the failures of the streetlights for each failure location.
7 is a matching table of the total current i flowing through the branch power line in response to the safety voltage frequency and safety voltage, the number of failures, and the location of the failure.
8 is a diagram for explaining a method of classifying a short circuit and a ground fault.
9 is a schematic diagram of an operating system according to another embodiment of the present invention.
10 is a flowchart of a method for monitoring a diagnosis unit using a safety voltage.

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and will be described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all changes, equivalents, or substitutes included in the spirit and scope of the present invention.

In describing each drawing, similar reference numerals have been used for similar elements. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Terms such as first and second may be used to describe various constituent elements, but the constituent elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component.

For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

The term and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as'comprise' or'have' are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

Unless otherwise defined, all terms used herein including technical or scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

Hereinafter, a big data and AI-based street light portal operating system (hereinafter, referred to as “operating system”) according to a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 8. In order to clarify the gist of the present invention, a description of conventionally well-known matters will be omitted or simplified.

Referring to FIG. 1, the operating system includes at least one street light distribution network (1000-1, 1000-2, ..., 1000-n, hereinafter, collectively referred to as '1000'), a diagnostic service device 200, and a communication network. It may include (300). One street light distribution network can form one street light distribution site. A streetlight distribution site can supply power to streetlights belonging to that site.

2, the street light distribution network may include a street light distribution panel 10 and a street light (L11, L12, L13, L14, L21, L22, L23, L31, L32) receiving power from the streetlight distribution panel 10. have.

The street light distribution board 10 includes a main circuit breaker 11 and MCCB that can cut off the supply of power to the street light by branching the power supplied through the main power line 1 to the branch power lines 2a, 2b, 2c. can do.

There may be at least one branch power line. 2 illustrates a case where there are three branch power lines. In FIG. 2, reference numeral 2a denotes a first branch power line, 2b denotes a second branch power line, and 2c denotes a third branch power line.

At least one street light may be connected to the branch power line. When a plurality of street lights are installed on a single branch power line, the plurality of street lights may be electrically connected in parallel to the single branch power line. 2 shows that four street lights are installed on the first branch power line 2a, three street lights are installed on the second branch power line 2b, and two street lights are installed on the third branch power line 2c. Illustrate the case.

An intelligent street light distribution network monitoring device 100 (hereinafter, referred to as a “monitoring device”) using a safety voltage may be installed on the street light distribution panel 10 side.

The monitoring device 100 may include a safety voltage supply unit 110, a measurement unit 120, a diagnosis unit 130, and a first communication unit 140.

The safety voltage supply unit 110 may supply a safety voltage to the branch power line. The safety voltage may be an AC voltage that does not have the risk of electric shock and has a voltage level lower than that of the commercial power supply. The safety voltage may be, for example, 30 [V]. In consideration of the risk of electric shock, a voltage lower than 30 [V} may be selected. When the supply of the safety voltage is started, the frequency of the safety voltage may be a reference frequency. Here, the reference frequency may be 20 kHz. Safe voltage can be supplied during the daytime when streetlights are turned off. The safety voltage supply unit 110 may supply a safety voltage at a preset time for diagnosis of a streetlight distribution network.

The measurement unit 120 may detect the total current flowing through the branch power lines in response to the safety voltage for each branch power line using the CTs 21, 22, 23, and Current Transformer. To this end, the CTs 21, 22, and 23 may be installed at the branch start point of the branch power line. Hereinafter, the total current flowing through the branch power lines corresponding to the safety voltage for each branch power line measured by the measurement unit is collectively referred to as i.

The diagnosis unit 130 may determine whether or not the street light distribution network is abnormal and the type of the abnormality by using the total current flowing through the branch power line in response to the safety voltage for each branch power line detected through the measurement unit 120. To this end, a reference value for determining the type of abnormality may be set. In FIG. 5,'in' may be a total current value (hereinafter referred to as a'first reference value') flowing through the branch power line in response to a safety voltage in a normal state. in may be 30 A, for example. Here, the "normal state" means a state in which an abnormality such as a street light failure, a ground fault, and a short circuit does not occur on the separate power line.

'In+ix' may be a lower limit value of the total current flowing through the branch power line in response to the safety voltage determined as a ground fault (hereinafter, referred to as a'second reference value'). ix may be, for example, 10 A. ix may be arbitrarily selected by the designer, and may be an additional current value corresponding to a ground fault added to in in consideration of the field situation. 'In+iy' may be a lower limit value of the total current flowing through the branch power line in response to the safety voltage determined as a short circuit (hereinafter, referred to as a'third reference value'). iy may be, for example, 20 A. iy may be arbitrarily selected by a designer, and may be an additional current value corresponding to a short-circuit lost to in in consideration of field conditions. 'In-iz' may be an upper limit value of the total current flowing through the branch power line (hereinafter referred to as the'fourth reference value') in response to the safety voltage determined as a street light failure. iz can be, for example, 0.96 A. iz can be set by field survey. iz may be an amount of attenuation of the total current of the branch power line corresponding to a failure of a street light that causes a street light failure event in which the attenuation of the total current of the branch power line is the least among street lights connected to the branch power line. For example, iz in FIG. 4 may be i31 in FIG. 3.

If the total current i flowing through the branch power line in response to the safety voltage is less than or equal to the fourth reference value, the diagnosis unit 130 may determine that a failure has occurred in the street light connected to the branch power line. In contrast, if the total current flowing through the branch power line in response to the safety voltage exceeds the fourth reference value, the diagnosis unit 130 may determine that a failure has not occurred in the street light connected to the branch power line. When it is determined that the street light is not broken, the diagnosis unit 130 may determine whether there is a ground fault or a short circuit. In this case, if the total current flowing through the branch power line in response to the safety voltage is equal to or greater than the second reference value and less than the third reference value, the diagnosis unit 130 may determine that a ground fault has occurred in the corresponding branch power line. In contrast, if the current flowing through the branch power line corresponding to the safety voltage is equal to or greater than the third reference value, the diagnosis unit 130 may determine that a short circuit has occurred in the corresponding branch power line. In contrast, if the current flowing through the branch power line in response to the safety voltage exceeds the fourth reference value and is less than the second reference value, the diagnosis unit 130 may determine that an abnormality in the streetlight distribution network has not occurred in the corresponding branch power line. . When it is determined as a ground fault or short circuit, the diagnostic unit 130 may provide an alarm notifying that the fault or short circuit is external. Alternatively, the diagnosis unit 130 may determine whether a ground fault or a short circuit occurs prior to determining whether a street light is broken. On the contrary, the diagnostic unit 130 has the total current i flowing through the branch power line in response to the safety voltage regardless of short-circuit, ground fault, normal, and street light failure determination. It is possible to determine whether a short circuit, a ground fault, a normal, or a street light is broken by determining which of the current values corresponding to.

When it is determined by the diagnosis unit 130 that a streetlight failure event has occurred, the safety voltage supply unit 110 may change the frequency. In this case, the safety voltage supply unit 110 may change the frequency of the safety voltage in a form of lowering the frequency from the reference frequency. Hereinafter, for convenience of description, the description will be made based on the second branch power line. Referring to FIG. 3, it can be seen that the 2-1 street lamp L21, the 2-2 street lamp L22, and the 2-3 street lamp L23 are connected in parallel to the second branch power line 2b. . FIG. 4 shows currents (i, i11, i12, i21, i22, i31) in the current path in consideration of line impedance (ZL1, ZL2, ZL3) and street light impedance (Zlamp) in the circuit of FIG. 3. In this case, the equivalent impedance of the branch power line viewed in the X direction may be as shown in the following equation.

here,

X: Inductive reactance of the line

R: equivalent resistance

In addition, the total current i flowing through the branch power line in response to the safety voltage calculated based on the equivalent impedance may be as shown in the following equation.

here,

V: safety voltage

Z: equivalent impedance of branch power line

i: Total current flowing through the branch power line in response to the safety voltage

As shown in Equation 2, the magnitude of the total current flowing through the branch power line in response to the safety voltage has a large influence on the frequency (f). Therefore, when a diagnosis is performed using a high frequency such as 20 kHz, the magnitude of the total current flowing through the branch power line in response to the safety voltage may be very small. Therefore, the reliability of diagnosis may be low due to the limitation of the detection capability of the CT.

Referring to FIG. 6, depending on the number of faults and the location of the faults, the total current flowing through the branch power line may be different in response to the safety voltage. For example, when only the 2-3rd street light L23 fails, the total current i flowing through the branch power line in response to the safety voltage may be'in-i31'. Here, in may be the total current flowing through the branch power line in response to a safety voltage when a street light wired to the branch power line has no failure. Accordingly, when a current corresponding to in-i31 is detected, the diagnosis unit 130 can recognize that the number of streetlight failures is one, and the failure location is the 2-3rd street light L23.

Based on this point, it is possible to specify the current value according to the fault by the number of faults and the fault location. In this case, it is assumed that the frequency of the safety voltage is fixed to a single frequency (eg, 20 kHz).

6 is a table specifying the number of faults and current values according to faults for each fault location. FIG. 6 was created based on the currents i, i11, i12, i21, i22, i31 shown in FIG. 4. In FIG. 6,'in' may be the total current flowing through the branch power line in response to the safety voltage when no abnormality such as a street light failure, ground fault, or short circuit occurs in the branch power line. 'i' may be the total current flowing through the branch power line in response to the safety voltage measured through the measurement unit. In FIG. 5, the fault location column represents a street light in which a fault has occurred in L21, L22, and L23, and i11, i21, and i31 represent the current flowing through the street light in a state where there is no street light fault.

However, as previously seen, the total current i flowing through the branch power line in response to the safety voltage measured through the measurement unit 120 is greatly affected by the frequency of the safety voltage. If a single high-frequency safety voltage is used, the inductive reactance (X) can be large. Accordingly, the magnitude of the total current flowing through the branch power line may be small in response to the safety voltage. Therefore, when the number of faults and the fault section are classified using the total current of the branch power line corresponding to a single high-frequency safety voltage, it may not be easy to distinguish the number of faults and the fault section. In other words, the number of failures and the resolution for the failure section may be lowered. In order to increase the resolution, it is not possible to increase the size of the safety voltage. This is because the higher the level of the safety voltage, the higher the risk of electric shock. Also, it is not possible to lower the frequency of the safety voltage. This is because inductive reactance reflects factors such as changes in the aging of the line and must be detected again. In addition, there is a limit to increasing the detection capability of CT. This is because the product cost is very high, and there is a limiting performance even in the increase of the detection capability of CT.

That is, it may be difficult to determine the exact number of failures and failure sections by having a table as shown in FIG. 6 and determining which row of the tables corresponds to.

Referring to FIG. 7, a matching table of the total current i flowing through the branch power line in response to the safety voltage frequency and the safety voltage, the number of failures, and the location of the failures is shown.

When it is determined that a street light failure event has occurred, the diagnosis unit 130 may change the safety voltage frequency. When a streetlight failure event occurs, the diagnosis unit 130 may control the safety voltage supply unit 110 to continuously lower the safety voltage frequency. In addition, the diagnostic unit 130 varies the frequency of the safety voltage, and the total current i flowing through the branch power line in response to the safety voltage is the first reference value (in response to the safety voltage in the normal state). It is possible to extract the safe voltage frequency or frequency range which is the total current value flowing through the device.

7 shows an example of extracting the number of failures and the failure section with a safe voltage frequency. In the event of such a streetlight failure, the total current (i) flowing through the branch power line in response to the safety voltage is the first reference value (total current flowing through the branch power line in response to the safety voltage in a normal state). By selecting the safety voltage frequency or frequency range to be used, the resolution for the fault section and fault location can be increased. This is because the intervals of frequencies or frequency ranges that specify a plurality of fault sections and fault locations, respectively, are considerably larger than the intervals of the total current flowing through the branch power line in response to the safety voltage. The diagnostic unit 130 determines whether the total current i flowing through the branch power line reaches a first reference value in response to the safety voltage while lowering the safety voltage frequency, and when reaching the first reference value, the frequency of the safety voltage You can stop controlling to vary.

In addition, the diagnostic unit 130 determines that the total current i flowing through the branch power line in response to the safety voltage becomes the first reference value (the total current value flowing through the branch power line in response to the safety voltage when in a normal state). You can select a safety voltage frequency or frequency range, and determine the number of faults and fault section information matching the frequency or frequency range. In this case, the matching table as shown in FIG. 7 may be used to determine the number of failures and information on the failure section of the diagnosis unit 130. Alternatively, a separate determination algorithm, an AI engine, etc. for determining the number of failures and the failure section may be introduced.

The operator uses any one of field measurement, experimental data, and simulation to measure the total current (i) flowing through the branch power line in response to the safety voltage as the first reference value (the branch power line in response to the safety voltage when it is in a normal state). The safety voltage frequency or frequency range can be determined.

The diagnosis unit 130 may provide the total current flowing through the branch power line (hereinafter, referred to as “total current”) to the diagnosis service device 200 in response to the safety voltage measured by the measurement unit 120.

The first communication unit 140 may provide communication between the diagnostic service device 200 and the monitoring device 100.

The diagnostic service device 200 may include a second communication unit 210, a big data unit 220, and an AI unit 230.

The second communication unit 210 may provide communication with the monitoring device 100. In this case, the communication network may have a wired, wireless, wired/wireless mixed form, and the present invention does not limit the applied communication standard.

The big data unit 220 may collect the total current from at least one streetlight distribution network 1000 in real time. The big data unit 220 may manage total current data by dividing it into a streetlight distribution network identifier, a branch power line identifier, and a data collection time.

The AI unit 230 may use the total current on the big data unit 220 to determine the signs of an abnormality in the streetlight distribution network. The AI unit 230 may evaluate the abnormal event index of the streetlight distribution network using the total current on the big data unit 220. Here, the abnormal event index may be 1) a street light failure probability 2) a short circuit rate 3) a ground fault rate, and the like. And, if the event index exceeds a preset criterion, an alarm may be provided to the outside.

Hereinafter, a function of determining the probability of a street light failure of the AI unit 230 will be described.

AI unit 230 according to the following equation. You can judge the probability of a street light failure.

here,

i: Total current flowing through the branch power line in response to the safety voltage for each branch power line measured by the measuring unit

in: Total current flowing through the branch power line in response to the safety voltage in a normal state

iz: Attenuation of the total current of the branch power line in response to a failure of a street light that causes the streetlight failure event with the smallest attenuation of the total current of the branch power line among street lights connected to the branch power line.

In Equation 3,'i','in', and'iz' may be as seen in FIG. 5 previously.

The AI unit 230 may provide the probability of a street light failure to the outside through an interface. This allows the operator to establish a street light maintenance plan before the street light breaks down.

The AI unit 230 branches in response to the safety voltage for each branch power line measured by the measurement unit before determining the short-circuit rate and the ground fault rate, and branch in response to the safety voltage when the total current i flowing through the power line is in a normal state. It is possible to determine whether the cause of exceeding the total current value (in) flowing through the power line is either a short-circuit event or a ground fault event. In this case, the AI unit 230 may distinguish between a short-circuit event and a ground fault event by using the current rising property.

’는 단락에 대응한 전체 전류 곡선을 나타낸다. t1은 전체 전류가 ‘정상상태일 때 안전 전압에 대응해 분기 전원 라인에 흐르는 전체 전류값(in)’을 초과하기 시작한 시점을 나타낸다. t2는 AI부(230)가 단락 징후와 지락 징후 여부를 판단하는 시점을 나타낸다. 도 8에서와 같이 지락은 단락 대비 상대적으로 장주기로 전체 전류가 변화하고, 단락은 지락 대비 상대적으로 단주기로 전체 전류가 변화할 수 있다. In the graph of FIG. 8, the x-axis represents'time', and the y-axis represents'the total current flowing through the branch power line in response to the safety voltage for each branch power line measured by the measuring unit (i, hereinafter referred to as'total current')'. Show. And, in FIG. 8,'curve η'is the total current curve corresponding to the ground fault, and'curve η'

'Represents the total current curve corresponding to the short circuit. t1 represents the point in time when the total current begins to exceed'the total current value (in) flowing through the branch power line in response to the safety voltage when it is in a steady state'. t2 represents a point in time when the AI unit 230 determines whether there is a short-circuit sign or a ground fault sign. As shown in FIG. 8, the total current may change in a relatively long period compared to a short circuit, and in a short circuit, the total current may change in a relatively short period compared to the ground fault.

The AI unit 230 may calculate the current rise slope at each preset time according to the following equation.

here,

Δt: Time from when the total current value (i) exceeds the total current value (in) flowing through the branch power line in response to the safety voltage when the total current value (i) is in a normal state to the time when a short circuit or ground fault is judged

Δt: Excess of the total current value (in) flowing through the branch power line in response to the safety voltage in the normal state in the total current value (i)

The AI unit 230 may determine that it is a short-circuit symptom when the current rising slope exceeds a preset reference slope.

The AI unit 230 may determine that it is a ground fault if the current rising slope is less than or equal to a preset reference slope.

In response to determining that it is a ground fault indication, the AI unit 230 may determine the ground fault rate according to the following equation.

In Equation 5,'the lower limit value of the total current flowing through the branch power line in response to the safety voltage determined as a ground fault' may be the same as'in+ix' in FIG. 5.

The AI unit 230 may provide the calculated ground fault rate to the outside through an interface. This allows the operator to establish a street light maintenance plan before the ground fault.

In response to determining that there is a short circuit indication, the AI unit 230 may determine the short circuit rate according to the following equation.

In Equation 6,'the lower limit value of the total current flowing through the branch power line corresponding to the safety voltage determined as a short circuit' may be the same as'in+iy' in FIG. 5.

The AI unit 230 may provide the calculated short circuit rate to the outside through an interface. This allows the operator to establish a street light maintenance plan before the short circuit.

Hereinafter, an operating system according to another embodiment of the present invention will be described with reference to FIGS. 1 to 9. In order to clarify the gist of the present invention, matters overlapping with those described above are omitted or simplified. Configurations having the same function and operation as those described above are given the same reference numerals in FIG. 9.

Referring to FIG. 9, the operating system may include a street light distribution panel 10 and a street light (L11, L12, L13, L14, L21, L22, L23, L31, L32) receiving power from the streetlight distribution panel 10. . In addition, a street light monitoring device 100' using a safety voltage may be provided on the side of the street light distribution panel 10. The monitoring device 100 ′ may include a safety voltage supply unit 110, a measurement unit 120, and a first communication unit 140. The first communication unit 140 may transmit the measured value of the measurement unit 120 to the diagnostic service device 200 ′. Here, the measured value may be a total current value flowing through the branch power line in response to the safety voltage previously seen. Functions and operations of the safety voltage supply unit 110 and the measurement unit 120 may be the same as in FIG. 2.

The monitoring device 100' and the diagnostic service device 200' may communicate with each other through the communication network 300. In this case, the communication network may have a wired, wireless, wired/wireless mixed form, and the present invention does not limit the applied communication standard.

The diagnostic service device 200' may include a second communication unit 210, a big data unit 220, an AI unit 230, and a diagnosis unit 130'. The second communication unit 210 may provide communication between the diagnosis unit 130 ′ and the monitoring device 100 ′. The function and operation of the diagnosis unit 130' may be the same as in FIG. 2. However, the diagnostic unit 130' collects the measured values of the measurement unit 120 through the communication network 300, and transmits and receives a control command between the safety voltage supply unit 110 and the measurement unit 120 through the communication network 300. In this regard, it may have a difference from the diagnosis unit 130 of FIG. 2. The functions and operations of the big data unit 220 and the AI unit 230 may be the same as in FIG. 2.

Hereinafter, a method of diagnosing a diagnosis unit according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1 to 10. The configuration of the above operating system may be more clearly defined by the following description. The following description may be applied in common to the diagnosis unit of FIGS. 2 and 9.

First, referring to FIG. 10, the safety voltage supply unit 110 may supply a safety voltage to the branch power line (S1). The safety voltage may be an AC voltage that does not have the risk of electric shock and has a lower voltage level than the commercial power level. The safety voltage may be, for example, 30 [V]. In consideration of the risk of electric shock, a voltage lower than 30 [V] may be selected. When the supply of the safety voltage is started in S1, the frequency of the safety voltage may be a reference frequency. Here, the reference frequency may be 20 kHz. Safe voltage can be supplied during the daytime when streetlights are turned off.

The measurement unit 120 may detect the total current flowing through the branch power line in response to the safety voltage for each branch power line using the CTs 21, 22, and 23 (Current Transformer) (S2). To this end, the CTs 21, 22, and 23 may be installed at the branch start point of the branch power line. Hereinafter, the total current flowing through the branch power lines corresponding to the safety voltage for each branch power line is collectively referred to as i.

The diagnosis unit 130 may determine whether or not the streetlight distribution network is abnormal and the type of the abnormality by using the total current flowing through the branch power line in response to the safety voltage for each branch power line measured by the measurement unit in S2 (S3, S4). ). S3 and S4 may be performed in different order. Referring to FIG. 5, a reference value for determining the type of abnormality may be set. In FIG. 5,'in' may be a total current value flowing through the branch power line in response to a safety voltage in a normal state (hereinafter, referred to as a'first reference value'). in may be 30 A, for example. Here, the "normal state" means a state in which an abnormality such as a street light failure, a ground fault, and a short circuit does not occur on the separated power line.

'In+ix' may be a lower limit value of the total current flowing through the branch power line in response to the safety voltage determined as a ground fault (hereinafter, referred to as a'second reference value'). ix may be, for example, 10 A. ix may be arbitrarily selected by the designer, and may be an additional current value corresponding to a ground fault added to in in consideration of the field situation. 'In+iy' may be a lower limit value of the total current flowing through the branch power line in response to the safety voltage determined as a short circuit (hereinafter, referred to as a'third reference value'). iy may be, for example, 20 A. iy may be arbitrarily selected by a designer, and may be an additional current value corresponding to a short-circuit lost to in in consideration of field conditions. 'In-iz' may be an upper limit value of the total current flowing through the branch power line (hereinafter referred to as a'fourth reference value') in response to a safety voltage determined as a street light failure. iz can be, for example, 0.96 A. iz can be set by field survey. iz may be an amount of attenuation of the total current of the branch power line corresponding to a failure of a street light that causes a street light failure event in which the attenuation of the total current of the branch power line is the least among street lights connected to the branch power line. For example, iz in FIG. 5 may be i31 in FIG. 4.

In S3, if the total current i flowing through the branch power line in response to the safety voltage is less than or equal to the fourth reference value, the diagnosis unit 130 may determine that a failure has occurred in the street light connected to the branch power line. In contrast, if the total current flowing through the branch power line in response to the safety voltage exceeds the fourth reference value, the diagnosis unit 130 may determine that a failure has not occurred in the street light connected to the branch power line. If it is determined in S3 that the street light is not broken, the diagnosis unit 130 may determine whether there is a ground fault or a short circuit (S4). In this case, if the total current flowing through the branch power line in response to the safety voltage is equal to or greater than the second reference value and less than the third reference value, the diagnosis unit 130 may determine that a ground fault has occurred in the corresponding branch power line. In contrast, if the current flowing through the branch power line corresponding to the safety voltage is equal to or greater than the third reference value, the diagnosis unit 130 may determine that a short circuit has occurred in the corresponding branch power line. In contrast, in S4, if the current flowing through the branch power line in response to the safety voltage exceeds the fourth reference value and is less than the second reference value, it may be determined that an abnormality in the streetlight distribution network has not occurred in the branch power line. I can. When it is determined in S4 as a ground fault or a short circuit, the diagnostic unit 130 may provide an alarm notifying that there is a ground fault or a short circuit to the outside.

When it is determined that a streetlight failure event has occurred in S3, the safety voltage supply unit 110 may change the frequency. In this case, the safety voltage supply unit 110 may change the frequency of the safety voltage in a form of lowering the frequency from the reference frequency. Hereinafter, for convenience of description, the description will be made based on the second branch power line. Referring to FIG. 3, it can be seen that a 2-1 street lamp L21, a 2-2 street lamp L22, and a 2-3 street lamp L23 are connected in parallel to the second branch power line 2b. . FIG. 4 shows currents (i, i11, i12, i21, i22, i31) in the current path in consideration of the line impedance (ZL1, ZL2, ZL3) and streetlight impedance (Zlamp) in the circuit of FIG. 3. In this case, the equivalent impedance of the branch power line viewed in the X direction may be as shown in the following equation.

here,

X: Inductive reactance of the line

R: equivalent resistance

In addition, the total current i flowing through the branch power line in response to the safety voltage calculated based on the equivalent impedance may be as shown in the following equation.

here,

V: safety voltage

Z: equivalent impedance of branch power line

i: Total current flowing through the branch power line in response to the safety voltage

As shown in Equation 8, the magnitude of the total current flowing through the branch power line in response to the safety voltage has a large influence on the frequency (f). Therefore, when a diagnosis is performed using a high frequency such as 20 kHz, the magnitude of the total current flowing through the branch power line in response to the safety voltage may be very small. Therefore, the reliability of diagnosis may be low due to the limitation of the detection capability of the CT.

Referring to FIG. 4, according to the number of faults and the location of the faults, the total current flowing through the branch power line may be different in response to the safety voltage. For example, when only the 2-3rd street light L23 fails, the total current i flowing through the branch power line in response to the safety voltage may be'in-i31'. Here, in may be the total current flowing through the branch power line in response to a safety voltage when a street light wired to the branch power line has no failure. Accordingly, when a current corresponding to in-i31 is detected, the diagnosis unit 130 can recognize that the number of streetlight failures is one, and the failure location is the 2-3rd street light L23.

Based on this point, it is possible to specify the current value according to the fault by the number of faults and the fault location. In this case, it is assumed that the frequency of the safety voltage is fixed to a single frequency (eg, 20 kHz).

6 is a table specifying the number of streetlight failures and current values according to the failures of the streetlights for each failure location. FIG. 6 was created based on the currents i, i11, i12, i21, i22, i31 shown in FIG. 4. In FIG. 6,'in' may be the total current flowing through the branch power line in response to the safety voltage when no abnormality such as a street light failure, ground fault, or short circuit occurs in the branch power line. 'i' may be the total current flowing through the branch power line in response to the safety voltage measured through the measurement unit. In FIG. 6, the fault location column represents a street light in which a fault occurs in L21, L22, and L23, and i11, i21, and i31 represent the current flowing through the street light in a state where there is no street light fault.

However, as previously seen, the total current i flowing through the branch power line in response to the safety voltage measured through the measurement unit 120 is greatly affected by the frequency of the safety voltage. If a single high-frequency safety voltage is used, the inductive reactance (X) can be large. Accordingly, the magnitude of the total current flowing through the branch power line may be small in response to the safety voltage. Therefore, when the number of faults and the fault section are classified using the total current of the branch power line corresponding to a single high-frequency safety voltage, it may not be easy to distinguish the number of faults and the fault section. In other words, the number of failures and the resolution for the failure section may be lowered. In order to increase the resolution, it is not possible to increase the size of the safety voltage. This is because the higher the level of the safety voltage, the higher the risk of electric shock. Also, it is not possible to lower the frequency of the safety voltage. This is because inductive reactance reflects factors such as changes in the aging of the line and must be detected again. In addition, there is a limit to increasing the detection capability of CT. This is because the product cost is very high, and there is a limiting performance even in the increase of the detection capability of CT.

That is, it may be difficult to determine the exact number of failures and failure sections by having a table as shown in FIG. 6 and determining which row of the tables corresponds to.

Referring to FIG. 7, a matching table of the total current i flowing through the branch power line in response to the safety voltage frequency and the safety voltage, the number of failures, and the location of the failures is shown.

When it is determined that the streetlight failure event has occurred in S3, the diagnosis unit 130 may change the safety voltage frequency (S6). When a streetlight failure event occurs, the diagnosis unit 130 may control the safety voltage supply unit 110 to continuously lower the safety voltage frequency. In addition, the diagnostic unit 130 varies the frequency of the safety voltage, and the total current i flowing through the branch power line in response to the safety voltage is the first reference value (the branch power line in response to the safety voltage when in a normal state). It is possible to extract the safe voltage frequency or frequency range that is the total current value flowing in the (S7).

7 shows an example of extracting the number of failures and the failure section with a safe voltage frequency. In the event of such a street light failure, the total current (i) flowing through the branch power line in response to the safety voltage is the first reference value (total current flowing through the branch power line in response to the safety voltage in a normal state). By selecting the safety voltage frequency or frequency range to be used, the resolution for the fault section and fault location can be increased. This is because the intervals of frequencies or frequency ranges that specify a plurality of fault sections and fault locations, respectively, are considerably larger than the intervals of the total current flowing through the branch power line corresponding to the safety voltage. The diagnostic unit 130 determines whether the total current i flowing through the branch power line reaches a first reference value in response to the safety voltage while lowering the safety voltage frequency, and when reaching the first reference value, the frequency of the safety voltage You can stop controlling to vary.

In addition, the diagnostic unit 130 makes the total current i flowing through the branch power line in response to the safety voltage become the first reference value (total current value flowing through the branch power line in response to the safety voltage when in a normal state). The safety voltage frequency or frequency range may be selected, and the number of faults and fault section information matching the frequency or frequency range may be determined (S8). In this case, the matching table as shown in FIG. 7 may be used to determine the number of failures and information on the failure section of the diagnosis unit 130. Alternatively, a separate determination algorithm, an AI engine, etc. for determining the number of failures and the failure section may be introduced.

The operator uses any one of field measurement, experimental data, and simulation to measure the total current (i) flowing through the branch power line in response to the safety voltage as the first reference value (the branch power line in response to the safety voltage when it is in a normal state). The safety voltage frequency or frequency range can be determined.

The method may be performed in whole or in part. And, if necessary, it may be performed in a different order.

1: main power line
2a, 2b, 2c: sub power line
L11, L12, L13, L21, L22, L23, L31, L32: Street light
ZL1, ZL2, ZL2: line impedance
Zlamp: streetlight impedance
10: Street light distribution board
100, 100': Street light distribution network monitoring device
110: safety voltage supply unit
120: measurement unit
130, 130': diagnosis department
200, 200': diagnostic service device
210: communication department
220: Big Data Department
230: AI part
300: communication network

Claims (5)

A big data unit that collects the total current from at least one streetlight distribution network in real time; And
It includes an AI section that uses the total current on the big data section to determine signs of abnormalities in the streetlight distribution network,
The AI unit judges abnormal signs using the streetlight failure probability, short circuit rate, and ground fault rate,
The probability of failure of the street light is the following equation
[Equation]

here,
i: Total current flowing through the branch power line in response to the safety voltage for each branch power line measured by the measuring unit
in: Total current flowing through the branch power line in response to the safety voltage in a normal state
iz: Attenuation of the total current of the branch power line in response to the failure of the street light that causes the streetlight failure event with the smallest attenuation of the total current of the branch power line among streetlights connected to the branch power line.
Big data and AI-based streetlight portal operation system, characterized in that calculated by.
delete delete The method of claim 1,
The ground fault rate is the following equation
[Equation]

Big data and AI-based streetlight portal operation system, characterized in that calculated by.
The method of claim 1,
The short circuit rate is the following equation
[Equation]

Big data and AI-based streetlight portal operation system, characterized in that calculated by.

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