JP6775892B2 - Lightning surge detection circuit and lightning surge detection system - Google Patents

Description

The present invention relates to a lightning surge detection circuit for detecting a lightning surge and a lightning surge detection system.

It is known that if a lightning surge occurs due to the influence of lightning, the circuit may be damaged. Further, as described in Patent Document 1, a technique for protecting a circuit from a lightning surge is also known. In the technique described in Patent Document 1, when the lightning arrester is activated, a ground fault current flows, and this is detected as lightning information which is a kind of fault information.

Japanese Unexamined Patent Publication No. 2016-39714

By the way, in the technique described in Patent Document 1, the polarity of the lightning surge cannot be known, and the intrusion route of the lightning surge cannot be known.

The inventor of this case tried to solve this problem by diligently examining this point. An object of the present invention is to provide a lightning surge detection circuit capable of grasping a lightning surge intrusion route.

In order to solve the above problems, the following means will be adopted. The first means is a lightning surge detection circuit provided with a measurement unit capable of measuring the current of the ground wire, and the detection unit capable of detecting the value output from the measurement unit is on the positive side of the reference value. The detection unit is provided with a first detection unit in which a specific threshold value is set and a second detection unit in which a specific threshold value having the same value range as the specific threshold value of the first detection unit is set on the negative side of the reference value. It is a lightning surge detection circuit that determines which of the first detection unit and the second detection unit reaches the specific threshold value first by the connected determination unit, and determines the intrusion route of the lightning surge.

In the first means, the calculation unit connected to the measurement unit measures the time when the value output from the measurement unit exceeds a specific threshold value, and the determination unit connected to the calculation unit measures the time measured by the calculation unit. It is preferable that the configuration is such that a lightning surge is determined when the time exceeds the specified time.

In the first means, each of the first detection unit and the second detection unit has a plurality of threshold values, and the calculation unit is a value output from the measurement unit when the value output from the measurement unit exceeds the threshold value. The product of the absolute value of the difference between the maximum threshold value, which is the threshold value having the largest difference from the reference value, and the reference value among the threshold values reached by is obtained over time exceeding the maximum threshold value, is obtained, and the determination unit Is preferably configured to determine that it is a lightning surge when the product obtained by the calculation unit exceeds the determination value.

A lightning surge detection system including a plurality of lightning surge detection circuits according to the first means, which collects judgment information and position information of each lightning surge detection circuit, and collects judgment information and position information. It is preferable to use a lightning surge detection system including a mapping means for mapping. Further, it is preferable that the lightning surge detection system is provided with a specific means for identifying the central portion of the determination information. Further, it is preferable that the specifying means has a configuration in which the central portion is specified by using the negative electrode property determination value.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a lightning surge detection circuit capable of grasping an intrusion route of a lightning surge.

It is a conceptual diagram around the lightning surge detection circuit of this embodiment. It is a figure which showed the behavior of the voltage value when the current flows from the commercial power source side. It is a figure which showed the behavior of the voltage value when the current flows from the earth side. It is a flowchart which shows an example of the procedure of polarity determination. In the first example, it is a figure which shows the concept of the value to be compared with the determination value in the case where the voltage exceeding the threshold value V3 is detected. However, the shaded area represents the product. In the first example, it is a figure which shows the concept of the value to be compared with the determination value in the case where the detected maximum voltage value is V2 or more and less than V3. However, the shaded area represents the product. In the first example, it is a figure which shows the concept of the value to be compared with the determination value when the detected maximum voltage value is more than V1 and less than V2. However, the shaded area represents the product. It is a flowchart which shows an example of the lightning surge determination procedure. In the second example, it is a figure which shows the concept of the value to be compared with the judgment value. However, the shaded area represents the product. In the third example, it is a figure which shows the concept of the value to be compared with the determination value. However, the shaded area represents the product. It is an image diagram showing a state in which a thunderstorm is generated from a thunderstorm toward the ground. This is an example of mapping when a thunderstorm occurs from a thunderstorm to the ground. It is an image diagram showing a state where lightning is generated from the ground toward clouds. This is an example of mapping when lightning strikes from the ground toward clouds.

A mode for carrying out the invention is shown below. The lightning surge detection circuit 1 of the present embodiment is a lightning surge detection circuit 1 provided with a measuring unit 21 capable of measuring the current of the ground wire. The detection unit 22 capable of detecting the value output from the measurement unit 21 includes a first detection unit 13 in which a specific threshold value is set on the positive side of the reference value and a first detection unit 13 on the negative side of the reference value. The second detection unit 14 is provided with a specific threshold value having the same price range as the specific threshold value of the above. Further, the determination unit 15 connected to the detection unit 22 determines which of the first detection unit 13 and the second detection unit 14 first reaches the specific threshold value, and determines the intrusion route of the lightning surge. Therefore, the lightning surge detection circuit 1 can be used to grasp the intrusion route of the lightning surge.

As shown in FIG. 1, the ground wire 94 extending from the distribution board 92 connected to the commercial power supply 91 is provided with a lightning arrester 93 called an SPD (Surge Protective Device), and the current measuring unit 11 uses this lightning arrester. It is installed so as to measure the current on the ground plane side of 93. Further, the lightning surge detection circuit 1 of the present embodiment includes a waveform processing unit 12 that obtains current information from the current measurement unit 11. The first detection unit 13 and the second detection unit 14 obtain voltage information from the waveform processing unit 12. A calculation unit 16 that performs a calculation from the information of the waveform processing unit 12 is connected to the waveform processing unit 12. The lightning surge detection circuit 1 of the present embodiment includes a display unit 17 that displays information of the calculation unit 16 and information of the determination unit 15, and also includes a communication unit 18 that communicates each information to an external device or the like. .. The determination unit 15 that determines the lightning surge is connected to the first detection unit 13 and the second detection unit 14.

The calculation unit 16 of the present embodiment is a microcomputer, and calculates the voltage value and the integrated voltage value in time units by AD conversion from the voltage information from the waveform processing unit 12. With such a calculation unit 16, it can be used as a material for determining the deterioration state of the lightning arrester 93. This calculation information is output to the display unit 17 and the communication unit 18. Further, the calculation unit 16 may calculate the voltage information for the determination by the determination unit 15.

The display unit 17 of the present embodiment can detect and display a lightning surge. Further, the display unit 17 can also display the polarity, display the calculation information, and the like.

The communication unit 18 of the present embodiment can communicate with an external server or a communication terminal. Further, the communication unit 18 can also communicate the display contents of the display unit 17 and the location information.

The waveform processing unit 12 of the present embodiment converts current information into voltage information. The waveform processing unit 12 of this embodiment is set with a reference voltage V0, which is a voltage value when no measurement information is input.

The first detection unit 13 of the present embodiment provides a threshold value on the positive side from the reference voltage V0 set by the waveform processing unit 12. Further, the second detection unit 14 of the present embodiment provides a threshold value on the negative side from the reference voltage V0 set by the waveform processing unit 12.

When a current flows from the power supply side, as shown in FIG. 2, the voltage value is initially on the positive side of the reference voltage V0. Further, when a current flows from the ground side, as shown in FIG. 3, the voltage value is initially on the negative side of the reference voltage V0. Therefore, when the voltage value first reaches the threshold value of the first detection unit 13, it is known that the current is flowing from the power supply side, and when the voltage value first reaches the threshold value of the second detection unit 14, the current is from the ground side. You can see that is flowing.

The determination unit 15 of the present embodiment sets the detection unit on the side where the detected voltage reaches the threshold value first as the determination target of the lightning surge. With such a configuration, the polarity of the lightning surge can be known, so that the intrusion route of the lightning surge can be known.

Here, the procedure for determining the polarity will be described with reference to the flowchart shown in FIG. First, the current is detected by the current sensor used as the current measuring unit 11 (ST101). Next, the waveform processing unit 12 converts the current information into voltage information (ST102). It is confirmed whether or not the voltage information obtained from the waveform processing unit 12 reaches the threshold value of either the first detection unit 13 or the second detection unit 14 (ST103). When the voltage information reaches the threshold value on the second detection unit 14 side, it is determined that the intrusion is from the negative side (ST104). This polarity information is transmitted using a communication means (ST105). When the transmission is performed, the procedure for determining the polarity is completed.

When the voltage information reaches the threshold value on the first detection unit 13 side in step 103, it is determined that the intrusion is from the positive side (ST106). This polarity information is transmitted using a communication means (ST105). When the transmission is performed, the procedure for determining the polarity is completed.

In step 103, if the voltage information does not reach either the threshold value on the first detection unit 13 side or the threshold value on the second detection unit 14 side under a predetermined condition, it is determined that it is not lightning (ST107). After this determination is made, the procedure for determining the polarity ends.

Next, an example of conditions under which the determination unit 15 determines the lightning surge will be described. When the value output from the measurement unit 21 exceeds the threshold value, the calculation unit 16 integrates the output value over time to calculate the integral value, and the determination unit 15 calculates the integral value obtained by the calculation unit 16. When the value exceeds the judgment value, it is judged to be a lightning surge. As a result, the noise generated instantaneously can be excluded from the lightning surge determination, and the lightning surge can be detected with high accuracy. The first example, the second example, and the third example will be described below. In the first example, a plurality of threshold values are provided on the positive side or the negative side of the reference voltage V0. That is, each of the first detection unit 13 and the second detection unit 14 has a plurality of threshold values. Of these thresholds, for "the absolute value of the difference between the threshold (maximum threshold) and the reference voltage V0 having the largest difference from the reference voltage V0 at which the voltage has reached", "the voltage is equal to or higher than the threshold (maximum threshold)". The product is obtained by multiplying the "detected time", and when this product exceeds a predetermined determination value, it is determined that a lightning surge has occurred. This will be described with reference to FIGS. 5 to 7. In this example, three threshold values, V1, V2, and V3, are set. As shown in FIG. 5, when the voltage information obtained from the waveform processing unit 12 exceeds V3, the absolute value of the difference between the value of V3 and the reference voltage V0 and the voltage above V3 are detected. By multiplying the time, a value similar to the area of the shaded portion in FIG. 5 can be obtained. When this value exceeds the specified determination value, it is determined that a lightning surge has occurred.

As shown in FIG. 6, when the maximum voltage value of the voltage information obtained from the waveform processing unit 12 is V2 or more and less than V3, the absolute value of the difference between the value of V2 and the reference voltage V0 and the voltage above V2 When the value obtained by multiplying the detected times exceeds the predetermined determination value, it is determined that a lightning surge has occurred. As shown in FIG. 7, when the maximum voltage value of the voltage information obtained from the waveform processing unit 12 is V1 or more and less than V2, the absolute value of the difference between the value of V1 and the reference voltage V0 and the voltage above V1 When the value obtained by multiplying the detected times exceeds the predetermined determination value, it is determined that a lightning surge has occurred.

In this example, the determination value is set as one regardless of the magnitude of the voltage value. That is, the determination value is the same in any of the states shown in FIGS. 5 to 7. In this way, even if the maximum threshold value differs due to the difference in waveform, the lightning surge can be determined depending on whether the product (area) exceeds or does not exceed the unified determination value. Therefore, even if a lightning surge having a different waveform such as a pattern in which the voltage becomes high instantaneously or a pattern in which the low voltage continues for a certain period of time is input, it is possible to determine under the same conditions. Further, the calculation unit 16 connected to the measurement unit 21 measures the time when the value output from the measurement unit 21 exceeds the specific threshold value, and the determination unit 15 connected to the calculation unit 16 measures by the calculation unit 16. Since it is determined that the lightning surge occurs when the set time exceeds a predetermined time, the noise generated instantaneously can be excluded from the lightning surge determination, and the lightning surge can be detected with high accuracy.

Here, an example of the lightning surge determination procedure will be described with reference to the flowchart shown in FIG. First, it is confirmed that the voltage has reached V1 (ST201). After that, the area calculation for obtaining the above-mentioned product is performed (ST202). When it is confirmed that the voltage has reached V2 when the result of the area calculation has not reached the determination value (ST203), the area calculation for calculating the product is performed again (ST204). When it is confirmed that the voltage has reached V3 when the result of the area calculation has not reached the determination value (ST205), the area calculation for calculating the product is performed again (ST206). After that, if the determination value has not been reached under a predetermined condition, the lightning surge is not determined (ST207).

In step 202, if the result of the area calculation reaches the determination value, the lightning surge is determined (ST208). Further, in step 204, if the result of the area calculation reaches the determination value, the lightning surge is determined (ST209). Similarly, in step 206, if the result of the area calculation reaches the determination value, the lightning surge is determined (ST210).

In step 202, if the determination value is not reached under a predetermined condition as a result of the area calculation, the lightning surge is not determined (ST211). Further, in step 204, if the determination value is not reached under a predetermined condition as a result of the area calculation, the lightning surge is not determined (ST212). The predetermined condition for not determining the lightning surge is, in the first example, when the voltage falls below the maximum threshold value reached. Specifically, it is when it is below V3 in ST207, when it is below V1 in ST211 and when it is below V2 in ST212.

Next, a second example will be described with respect to an example of the condition under which the determination unit 15 determines the lightning surge. Also in the second example, a plurality of threshold values are set for each of the first detection unit 13 and the second detection unit 14. However, in the second example, as shown in FIG. 9, "the time from the time when a certain threshold value is exceeded to the time when the threshold value is lowered" or "from the time when a certain threshold value is exceeded, the reference voltage is V0". For the product obtained by multiplying a certain threshold value by "the time until the threshold value set so that the difference becomes large" is obtained, the sum of the products until the reference voltage V0 is reached again is the judgment value. When the value exceeds, the lightning surge is judged. In this way, since the area calculation is performed at each of the plurality of threshold values, the lightning surge can be determined with higher accuracy.

In addition, a third example will be described with respect to an example of the condition under which the determination unit 15 determines the lightning surge. Also in the third example, a plurality of threshold values are set for each of the first detection unit 13 and the second detection unit 14. However, in the third example, as shown in FIG. 10, the product of "the time from the threshold value at which the difference from the reference voltage V0 at which the voltage reached is the largest to below this threshold value" is multiplied by this threshold value. The product is calculated by multiplying the "threshold with the largest difference from the reference voltage V0 that the voltage at that time exceeds" and the "time until the voltage falls below this threshold" until the reference voltage V0 is reached again in order. When the sum of the products exceeds the judgment value, the lightning surge is judged. In the case of a lightning surge, it is assumed that the initial rise of the voltage value becomes steep, so after the voltage reaches the threshold value with the largest difference from the reference voltage V0, the area calculation is performed at multiple threshold values. When each of the above is performed, the lightning surge can be determined with high accuracy without requiring a highly accurate area calculation capability.

Note that, unlike the first to third examples, the lightning surge may be determined when the voltage reaches the threshold value.

When a plurality of such lightning surge detection circuits 1 are used, it is possible to collect big data of the polarity of the lightning surge. For example, a lightning surge detection system including a collecting means for collecting judgment information and position information for each lightning surge detection circuit 1 provided in a specific area, and a mapping means for mapping the collected judgment information and position information. If so, it is possible to collect big data on the polarity of lightning surges in a specific area.

The collecting means of the present embodiment collects determination information and position information of each lightning surge detection circuit 1 in a specific area. In addition, the calculation information of lightning in the calculation unit 16 can be collected. Therefore, the deterioration of the lightning arrester 93 can be estimated. Further, the mapping means of the present embodiment maps so that the information from the collecting means can be visually recognized.

By the way, in general, a thunderstorm has a negative charge in the lower layer of the cloud and a positive charge in the upper layer. In this case, as shown in FIG. 11, the negative charge collected in the lower layer of the thunderstorm attracts the positive charge on the ground, and a thunderstorm is generated from the thunderstorm toward the ground through a steel tower or a lightning rod. When a lightning strike occurs in this way, a lightning surge flows as shown in FIG. 11, and a lightning surge flows from the ground side in the building A near the lightning strike point. Further, the lightning surge flowing through the building A flows to the building B farther from the lightning strike point than the building A through the communication line or the electric wire. The lightning surge that flows through this building B flows to the ground.

Therefore, the lightning surge detection circuit 1 installed in the building A determines that the lightning surge has entered from the ground side. Further, the lightning surge detection circuit 1 installed in the building B determines that the lightning surge has entered from the power supply side.

When information is collected from these plurality of lightning surge detection circuits 1 and mapped, as shown in FIG. 12, a negative electrode property judgment (intrusion from the ground side) is located near the lightning strike point, and a positive electrode property judgment is performed outside the lightning surge detection circuit 1. (Intrusion from the power supply side) is located. Further outside, a point where a lightning surge is not determined is located. In FIG. 12, the black circle represents the point where the negative electrode property judgment was made, the white circle represents the point where the positive electrode property judgment was made, the triangle represents the point where the lightning surge was not judged, and the star mark is the central portion. Represents the point estimated as.

In addition, because the wind strength is different between the upper and lower layers, the clouds rise diagonally, and the positive charges accumulated in the upper layers attract the negative charges on the ground, causing thunderstorms from the ground toward the thunderstorms. .. In this case, as shown in FIG. 13, a lightning surge flows, and a lightning surge flows from the ground side of the building B. Further, the lightning surge that has flowed to the building B flows to the building A through the communication line or the electric wire. The lightning surge that flows through this building A flows to the ground.

Therefore, the lightning surge detection circuit 1 installed in the building B determines that the lightning surge has entered from the ground side. Further, the lightning surge detection circuit 1 installed in the building A determines that the lightning surge has entered from the power supply side.

When information is collected from these plurality of lightning surge detection circuits 1 and mapped, as shown in FIG. 14, a positive electrode property determination (intrusion from the power supply side) is located near the lightning strike point, and a negative electrode property determination is performed outside the lightning surge detection circuit 1. (Invasion from the ground side) is located. Further outside, a point where a lightning surge is not determined is located. In FIG. 14, the black circle represents the point where the negative electrode property judgment was made, the white circle represents the point where the positive electrode property judgment was made, the triangle represents the point where the lightning surge was not judged, and the star mark is the central portion. Represents the point estimated as.

By the way, by knowing the intrusion route of the lightning surge, it can be inferred that the central part is the lightning strike point when the polarity of the specific area is mapped. Therefore, the lightning surge detection system of the present embodiment is configured to include a specific means capable of identifying the central portion of the determination information from the mapping information. Since it can be inferred that the central part specified by using this specific means is the lightning strike point, it is possible to predict the movement of lightning. Further, when the central part is specified by the specific means, if the central part is specified by using the information of the negative electrode property determination place without using the information of the positive electrode property determination place, the lightning strike point can be easily specified. In this embodiment, mapping and central information are transmitted to a PC or the like via a network.

In this embodiment, the rectifier circuit is not provided. If a rectifier circuit is provided, a voltage drop occurs due to the resistance, and a weak current cannot be detected. However, if a rectifier circuit is not provided, such a situation can be avoided. Further, instead of providing the rectifier circuit, the first detection unit 13 and the second detection unit 14 are provided. With such a configuration, positive and negative polarities can be detected separately. Moreover, positive and negative polarities can be detected with a simple structure. Further, since it is not necessary to provide a large resistor like the diode of the rectifier circuit, the voltage drop is small and a weak current can be detected.

Although some embodiments have been described above, the present invention is not limited to the above embodiments and can be in various embodiments. For example, the function of the second detection unit may be provided in the first detection unit. It is also possible to provide a first detection unit and a second detection unit in the microcomputer.

The threshold values set by the first detection unit and the second detection unit can be changed according to the environment for detecting lightning surges such as noise.

The determination unit may be arranged anywhere, and may be, for example, in the detection unit or in the microcomputer.

The lightning surge detection circuit is not limited to the one via the SPD, the distribution board, and the system power supply as in the present embodiment. For example, it may be provided between the steel tower and the ground.

The first detection unit and the second detection unit may perform either the positive side detection or the negative side detection.

1 Lightning surge detection circuit 11 Current measurement unit 12 Waveform processing unit 13 First detection unit 14 Second detection unit 15 Judgment unit 16 Calculation unit 17 Display unit 18 Communication unit

Claims (6)

A lightning surge detection circuit equipped with a measuring unit that can measure the current of the ground wire.
The detection unit that can detect the value output from the measurement unit
The first detector with a specific threshold set on the positive side of the reference value,
And a second detection unit for the specific threshold specified threshold and width are the same of the first detection portion to the negative side is set than the reference value,
Wherein the detecting unit connected to the judging unit, the first one sensing unit and the second detection unit determines whether reaches the specified threshold above, the lightning surge detecting circuit for determining the entry pathway of lightning surge .. The connected operational unit and the measurement unit, the value output from the measurement unit measures the time that has exceeded the specific threshold,
The evaluation unit connected to said arithmetic unit, when exceeding the time period measured by the arithmetic unit is determined, the lightning surge detecting circuit of claim 1 wherein the determination that the lightning surge. Calculation unit, when the value output from the measurement unit exceeds a threshold value, integrating calculate the integrated value output value in time,
The determination unit, the lightning surge detecting circuit of claim 1, wherein the integral value obtained by the arithmetic unit is determined to be the lightning surge when exceeding the determination value. A lightning surge detection system including a plurality of lightning surge detection circuits according to claim 1.
Collecting means for collecting position information and determination information of the lightning surge detecting circuit of each
And mapping means for mapping collected the determination information and the position information,
Lightning surge detection system with. The lightning surge detection system according to claim 4, further comprising a specific means for identifying the central portion of the determination information. The lightning surge detection system according to claim 5, wherein the specific means identifies the central portion using a negative electrode property determination value.

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