JP6601678B2 - Lightning strike detection device and lightning strike detection method - Google Patents

Description

  The present invention, for example, when there is a lightning strike in an area centering on a structure such as a wind power generation facility, the lightning strike detection for determining whether the lightning strike is a lightning strike on the structure or a lightning strike on the periphery of the structure The present invention relates to a device and a lightning strike detection method.

  Lightning strikes (lightning strikes) are likely to occur in high-rise structures such as wind power generation facilities, and in such a case, the operation of the wind power generation facilities is forced to stop, resulting in a corresponding decrease in power generation. In this case, identify which wind power generation facilities had lightning strikes, lightning strikes on wind power generation facilities, or lightning strikes around wind power generation facilities, and promptly proceed with inspection and repair of the wind power generation facilities that received lightning strikes. There must be.

  As the current detection device, for example, a current detection device in an electronic device is disclosed in Patent Document 1. The current detection device includes a magnetic field detection unit that detects a magnetic field generated by a current, a calculation unit that calculates a current value based on a signal from the magnetic field detection unit, and an output unit that outputs the calculated current value. . The magnetic field detection unit includes first and second magnetic field sensors, and the calculation unit calculates a current value based on a magnetic field signal detected by the magnetic field sensor. According to this current detection device, it is possible to accurately calculate a current value while suppressing measurement errors due to the position of the magnetic field sensor.

JP 2013-210216 A

  In the current detection device having the conventional configuration described in Patent Document 1 described above, the measurement error due to the position of the magnetic field sensor is suppressed when measuring the current flowing through the wiring in the electronic device, and the current is measured accurately. It does not measure the current flowing through any other part. That is, it does not detect an excessive lightning current that flows suddenly through a structure such as a wind power generation facility, and does not measure a lightning current due to a lightning strike other than the structure.

Therefore, in this current detection device, it cannot be determined whether there is a lightning strike on the structure or whether there is a lightning strike around the structure, not the structure.
Accordingly, an object of the present invention is to provide a lightning strike detection device and a lightning strike detection method capable of easily discriminating whether a lightning strike to a structure or a lightning strike to the periphery of the structure with a simple configuration. It is in.

  In order to achieve the above object, the lightning strike detection device of the present invention has 3 to 20 magnetic field sensors arranged on the outer periphery of a structure that receives a lightning strike, and outputs signal signals measured by the magnetic field sensors during a lightning strike. Based on the polarity of the waveform, its integrated waveform, or its double integrated waveform, there is provided a discriminating device for discriminating whether it is a lightning strike on a structure or a lightning strike on its periphery.

The magnetic field waveform measured by each magnetic field sensor is preferably formed based on a magnetic field component extending in a tangential direction of a circle passing through each magnetic field sensor from the center of the structure.
Preferably, each magnetic field sensor is connected to a polarity detection circuit as a determination device that determines the polarity of the waveform of each magnetic field to be measured.

It is preferable that an integrating circuit or a double integrating circuit is connected to the magnetic field sensor, and the polarity detection circuit is connected to the integrating circuit or the double integrating circuit.
The lightning strike detection method using the lightning strike detection device determines that a lightning strike has occurred on a structure when the waveform of the output signal measured by each magnetic field sensor, its integrated waveform or its double integrated waveform have the same polarity. When it is of different polarity, it is determined that it is a lightning strike around the structure.

  The magnetic field waveform as an output signal measured by each magnetic field sensor has the same polarity when the direction of the magnetic field component extending in the tangential direction of the circle passing through the magnetic field sensor from the center of the structure is the same polarity, In some cases, it is preferable to have different polarity.

  It is preferable to select and discriminate a waveform from which the polarity can be determined among the waveform of the output signal, its integrated waveform, and its double integrated waveform.

  According to the lightning strike detection device and the lightning strike detection method of the present invention, there is an effect that it is possible to easily determine whether the lightning strike is on the structure or the lightning strike on the periphery of the structure with a simple configuration.

The schematic plan view which shows the case where a lightning strike was in the periphery of a tower body or a tower body in the state which has arrange | positioned three magnetic field sensors in the outer peripheral part of the tower body of the wind power generation equipment in 1st Embodiment. Explanatory drawing which shows an example of a magnetic field sensor. The schematic explanatory drawing which shows the whole wind power generation equipment. The graph which shows the waveform of a lightning strike current. The graph which shows the waveform of the magnetic field measured by three magnetic field sensors when there is a lightning stroke in the tower body. The graph which shows the waveform of the magnetic field measured by three magnetic field sensors when there was a lightning strike around the tower body y. The graph which shows the waveform of the magnetic field measured by three magnetic field sensors, when there is a lightning strike around the tower body z. The block diagram which shows the lightning strike detection apparatus in case the waveform of the voltage which is an output signal by a magnetic field sensor resembles the waveform of a lightning strike current. The block diagram which shows the lightning strike detection apparatus in case the waveform of the voltage which is an output signal by a magnetic field sensor resembles the differential waveform of a lightning strike current. The block diagram which shows the lightning strike detection apparatus in case the waveform of the voltage which is an output signal by a magnetic field sensor resembles the waveform of a lightning strike current. The block diagram which shows the lightning strike detection apparatus in case the waveform of the voltage which is an output signal by a magnetic field sensor resembles the differential waveform of a lightning strike current. The schematic plan view which shows the case where a lightning strike was in the periphery of a tower body or a tower body in the state which has arrange | positioned two magnetic field sensors in the outer peripheral part of the tower body of the wind power generation equipment in a reference form. The graph which shows the waveform of a lightning strike current. The graph which shows the waveform of the magnetic field measured by two magnetic field sensors when there is a lightning stroke in the tower body. The graph which shows the waveform of the magnetic field measured by two magnetic field sensors, when there is a lightning strike around the tower body y. The graph which shows the waveform of the magnetic field measured by two magnetic field sensors, when there is a lightning strike around the tower body z.

(First embodiment)
1st Embodiment of this invention is described in detail based on FIGS. In the first embodiment, a case where three magnetic field sensors 16 are used will be described.

  As shown in FIG. 3, the foundation 11 of the wind power generation facility 12 as a structure that receives lightning strikes is embedded in the ground 11, and a tower body 14 extends upward in the vertical direction from the foundation part 13. A plurality (three in this embodiment) of wind turbine blades 15 are attached to the top. The wind turbine blades 15 are configured to generate power by the wind power generation facility 12 by receiving wind and rotating.

  As shown in FIG. 1, three magnetic field sensors (magnetic sensors) 16 (16a, 16b, 16c) constituting a lightning strike detection device are located at positions 120 degrees apart in the circumferential direction of the outer peripheral portion of the tower body 14. The magnetic field generated by the lightning current flowing in the tower body 14 is detected when the tower body 14 has a lightning stroke. In FIG. 1, the mark “X” represents that the lightning current flows from the top of the tower body 14 to the base 13, that is, from the top to the bottom of the page.

  Here, the waveforms of the magnetic fields measured by the magnetic field sensors 16a, 16b, and 16c are magnetic field components m1, m2, and m3 that extend from the center x of the tower body 14 in the tangential direction of a circle that passes through the magnetic field sensors 16a, 16b, and 16c. Formed on the basis of Here, the polarities of the magnetic field sensors 16a, 16b, and 16c are positive in the clockwise direction around the tower body 14. Now, when a lightning strike current marked with a circle in the circle y flows in the periphery y, a clockwise magnetic field is generated around the periphery y, and the magnetic field component m1 of the magnetic field sensor 16a has a positive polarity (clockwise in FIG. 1). The magnetic field component m2 of the magnetic field sensor 16b has a negative polarity (counterclockwise in FIG. 1) and the magnetic field component m3 of the magnetic field sensor 16c has a positive polarity (clockwise in FIG. 1).

  As shown in FIG. 2, the magnetic field sensor 16 is configured by winding a conducting wire 18 such as an enameled wire around the outer periphery of a magnetic body 17 having a cylindrical shape, for example. By connecting an electric resistance wire 21 between the output terminals 19 and 20 of the conductor 18, an output signal is generated between the output terminals 19 and 20 based on a current flowing through the electric resistance wire 21 due to a magnetic field generated in the magnetic body 17. As a voltage is generated. The waveform of the generated voltage is output by an output device (display device) not shown. In addition, the electrical resistance value of the electrical resistance wire 21 is appropriately set according to measurement conditions and the like.

  This voltage waveform is similar to the current flowing through the tower 14 when the electric resistance value of the electric resistance line 21 between the output terminals 19 and 20 is small, and the electric resistance value between the output terminals 19 and 20 is When it is large or when the output terminals 19 and 20 are open, a waveform similar to the differential waveform of the current flowing through the tower body 14 is obtained. The waveform of the magnetic field or current as the output signal detected by the magnetic field sensor 16 is also similar to the current flowing through the tower body 14 or the differential waveform of the current flowing through the tower body 14. That is, the output signal of the magnetic field sensor 16 may be similar to the lightning current waveform or may be similar to the differential waveform of the lightning current.

The waveform of the lightning strike current due to the lightning strike is formed as shown in FIG. 4, for example, so that the current value increases immediately after the lightning strike to form a peak, and then the current value gradually decreases.
As shown in FIG. 5, when there is a lightning strike on the tower body 14, it can be considered that the lightning strike current passes through the center x of the tower body 14, and at that time, the tower body 14 is centered around the center x of the tower body 14 in the clockwise direction. Magnetic field is generated. In the magnetic field waveforms measured by the three magnetic field sensors 16a, 16b, and 16c, the magnetic field value increases immediately after a lightning strike to form a peak, and then the magnetic field value gradually decreases. That is, in this case, the polarities of the magnetic field waveforms obtained from the magnetic field sensors 16a, 16b, and 16c are the same.

  As shown in FIG. 6, when a lightning strike occurs around the tower body 14, a magnetic field is generated clockwise around the circumference y. At this time, in the waveform of the magnetic field measured by the magnetic field sensor 16b closest to the periphery y, the magnetic field value decreases and a bottom is formed immediately after a lightning strike, and then the magnetic field value gradually increases. The other two magnetic field sensors 16a and 16c are located approximately equidistant from the periphery y, and immediately after a lightning strike, the magnetic field rises to form a peak, and then the magnetic field gradually decreases. That is, the waveforms of the magnetic fields measured by one magnetic field sensor 16b and the other two magnetic field sensors 16a and 16c have opposite polarities.

  As shown in FIG. 1, the magnetic field waveform measured by each magnetic field sensor 16a, 16b, 16c extends from the center x of the tower body 14 in the tangential direction of a circle passing through each magnetic field sensor 16a, 16b, 16c. This is because the magnetic field components m1, m2, and m3 are formed. That is, the magnetic field components m1 and m3 of the magnetic field sensors 16a and 16c have a positive polarity, and the magnetic field component m2 of the magnetic field sensor 16b has a negative polarity.

  Subsequently, as shown by a two-dot chain line in FIG. 1, when a lightning strike occurs in the vicinity z of the tower body 14, a magnetic field is generated clockwise around the periphery z. At this time, the two magnetic field sensors 16a and 16b closest to the periphery z are located at approximately the same distance from the periphery z. For this reason, as shown in FIG. 7, the magnetic field waveform measured by these magnetic field sensors 16a and 16b has a magnetic field value that decreases and a bottom is formed immediately after a lightning strike, and then the magnetic field value gradually increases.

  As shown by the two-dot chain line in FIG. 1, the other one magnetic field sensor 16c is located farthest from the periphery z. Therefore, as shown in FIG. 7, the magnetic field value increases immediately after a lightning strike to form a peak, and then the magnetic field value gradually decreases. That is, the magnetic field waveforms measured by the two magnetic field sensors 16a and 16b and the other one magnetic field sensor 16c have opposite polarities.

  As described above, in the case of a lightning strike on the tower 14, the polarities of the magnetic field waveforms measured by the magnetic field sensors 16 a, 16 b, and 16 c match, and in the case of a lightning strike to the periphery, they do not match, It is possible to determine whether the lightning strikes the tower body 14 or the lightning strikes around the tower body 14. That is, by comparing the polarities of the waveforms of the output signals measured by the magnetic field sensors 16a, 16b, and 16c at the time of the lightning strike, it is possible to discriminate between the lightning strike on the tower body 14 and the lightning strike around it by the discrimination device. .

Next, a lightning strike detection apparatus and a lightning strike detection method for determining whether the magnetic field sensor 16 is a lightning strike on the tower body 14 or a lightning strike around the tower body 14 will be described.
As described above, the output signal of the magnetic field sensor 16 may be similar to the lightning strike current waveform or may be similar to the lightning strike differential waveform. When determining the polarity, the waveform similar to the lightning strike current waveform may be too steep to be difficult to determine. In that case, it is effective to smooth the waveform by integrating. By integrating a waveform similar to the lightning current waveform, a waveform similar to the lightning charge waveform is obtained. That is, the polarity determination may be performed with a waveform similar to the lightning strike current or with a waveform similar to the lightning strike waveform.

  FIG. 8 is a block diagram when the output signal of the magnetic field sensor 16 resembles the waveform of a lightning stroke current, and the polarity is determined with a waveform similar to the lightning stroke current. In this block diagram, when the voltages as the output signals of the three magnetic field sensors 16a, 16b, and 16c are similar to the lightning current waveform, each of the magnetic field sensors 16a, 16b, and 16c is a polarity detection circuit 22 as a discrimination device. Connected to. In this case, a waveform similar to the lightning current waveform is input to the polarity detection circuit 22 and the polarity is determined. The polarity detection circuit 22 is connected to the recording / warning device 23, and the GPS (Global Positioning System) 24 is also connected to the recording / warning device 23. Then, the polarity detection circuit 22 determines whether the lightning strike to the tower body 14 or the lightning strike to the periphery of the tower body 14 and if it is determined that the lightning strike to the tower body 14, the position of the tower body 14 is determined. Is recorded on the map and a warning is issued. Moreover, even if it does not use GPS, when it is discriminate | determined as the lightning strike to the tower body 14, the information regarding the tower body 14 can also be transmitted with an alarm.

  FIG. 9 is a block diagram in the case where the output signal of the magnetic field sensor 16 resembles the differential waveform of the lightning strike current, and the polarity is determined with a waveform similar to the lightning strike current waveform. As shown in this block diagram, when the voltage that is the output signal of each magnetic field sensor 16a, 16b, 16c is similar to the differential waveform of the lightning strike current, each magnetic field sensor 16a, 16b, 16c passes through an integration circuit 25, respectively. Are connected to the polarity detection circuit 22. That is, in this case, a waveform similar to the lightning strike waveform is input to the polarity detection circuit 22. The polarity detection circuit 22 is connected to the recording / warning device 23, and the GPS 24 is also connected to the recording / warning device 23.

  FIG. 10 is a block diagram when the output signal of the magnetic field sensor 16 resembles a lightning stroke current waveform and the polarity is determined with a waveform resembling the lightning stroke current waveform. As shown in this block diagram, when the waveform of the voltage, which is the output signal of each magnetic field sensor 16a, 16b, 16c, is similar to the waveform of the lightning current, each magnetic field sensor 16a, 16b, 16c passes through an integration circuit 25, respectively. Are connected to the polarity detection circuit 22. In this case, a waveform similar to a lightning strike charge waveform is input to the polarity detection circuit 22. The polarity detection circuit 22 is connected to the recording / warning device 23, and the GPS 24 is also connected to the recording / warning device 23.

  FIG. 11 is a block diagram in the case where the output signal of the magnetic field sensor 16 resembles a lightning stroke current waveform, and the polarity is determined with a waveform resembling the lightning stroke charge waveform. As shown in the block diagram, when the waveform of the voltage, which is the output signal of each magnetic field sensor 16a, 16b, 16c, is similar to the differential waveform of the lightning strike current, each magnetic field sensor 16a, 16b, 16c is double integrated. The polarity detection circuit 22 is connected through the circuit 26. In this case, a lightning strike waveform is input to the polarity detection circuit 22. The polarity detection circuit 22 is connected to the recording / warning device 23, and the GPS 24 is also connected to the recording / warning device 23.

An effect | action is demonstrated about the lightning strike detection apparatus of 1st Embodiment comprised as mentioned above.
As shown in FIGS. 1 and 3, when detecting whether the lightning strike is on the tower body 14 or on the periphery of the tower body 14, three magnetic field sensors are provided at the outer periphery of the lower end of the tower body 14. 16a, 16b, and 16c are arranged.

  When a lightning strike occurs in the tower body 14 or the vicinity thereof, the magnetic fields are measured by the magnetic field sensors 16a and 16b, respectively. When the magnetic field waveforms obtained by the magnetic field sensors 16a, 16b, and 16c have the same polarity as shown in FIG. 5, it can be determined that the lightning strike was at the center x of the tower body 14.

  On the other hand, as shown in FIG. 6 or FIG. 7, the waveform of the magnetic field obtained by any one of the magnetic field sensors 16 is opposite to the waveform of the magnetic field obtained by the other two magnetic field sensors 16. In the case of indicating the polarity, it can be easily determined that the lightning strike was around the tower body 14 due to the difference in magnetic field polarity.

  In this way, whether the lightning strike is to the tower body 14 or to the periphery of the tower body 14 is quickly determined based on the magnetic field polarities measured by the three magnetic field sensors 16a, 16b, and 16c. Can do.

Therefore, the effects exhibited by the first embodiment will be collectively described below.
(1) In the lightning strike detection device of the first embodiment, 3 to 20 magnetic field sensors 16 are arranged on the outer periphery of the tower body 14. Then, based on the waveform of the output signal measured by each magnetic field sensor 16 at the time of the lightning strike, the integral waveform thereof, or the polarity of the double integral waveform thereof, it is discriminated whether the lightning strikes the tower body 14 or the lightning strikes around the tower body 14. Is provided. For this reason, the lightning strike point can be easily determined by determining the polarity of the waveform based on the output signal by the determination device.

Therefore, according to the lightning strike detection apparatus of the first embodiment, it is possible to easily determine whether the lightning strikes the tower body 14 or the lightning strikes around the tower body 14 with a simple configuration.
(2) The waveform of the magnetic field measured by each magnetic field sensor 16 is formed based on a magnetic field component extending in the tangential direction of a circle passing through each magnetic field sensor 16 from the center of the tower body 14. Accordingly, it is possible to easily detect the polarity of the magnetic field with reference to the obtained magnetic field component.

  (3) Each magnetic field sensor 16 is connected to a polarity detection circuit 22 as a determination device for determining the polarity of the waveform of each magnetic field to be measured. Therefore, the polarity of the output signal of the magnetic field sensor 16 can be detected by the polarity detection circuit 22, and the lightning strike to the tower body 14 and the lightning strike to the periphery thereof can be easily discriminated.

  (4) An integrating circuit 25 or a double integrating circuit 26 is connected to the magnetic field sensor 16, and the polarity detection circuit 22 is connected to the integrating circuit 25 or the double integrating circuit 26. For this reason, the polarity can be determined more satisfactorily by integrating or double integrating the output signals of the magnetic field sensors 16 to obtain, for example, a charge waveform.

  (5) In the lightning strike detection method of the first embodiment, when the waveform of the output signal measured by each magnetic field sensor 16, its integrated waveform, or its double integrated waveform has the same polarity, it is a lightning strike to the tower body 14. If it is different polarity, it is determined that it is a lightning strike around the tower 14. Therefore, it is possible to easily determine whether the lightning strikes the tower body 14 or the lightning strikes around the tower body 14 only by determining the difference in polarity.

  (6) The magnetic field waveform measured by each magnetic field sensor 16 has the same polarity when the direction of the magnetic field component extending in the tangential direction of the circle passing through each magnetic field sensor 16 from the center of the tower body 14 is the same direction, and the reverse direction Is the case of different polarity. Based on such polarity criteria, the difference in polarity can be clearly determined.

  (7) Of the waveform of the output signal, its integrated waveform, and its double integrated waveform, a waveform capable of determining polarity is selected and determined. For this reason, for example, by integrating or double integrating the output signal to obtain a charge waveform, the waveform can be smoothed to improve the accuracy of polarity determination.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the second embodiment, the case where four or more magnetic field sensors 16 are used will be mainly described, and the description overlapping with the first embodiment will be omitted.

  When four or more magnetic field sensors 16 are arranged on the outer periphery of the tower body 14, the polarity of the magnetic field is set in the same manner as when the three magnetic field sensors 16a, 16b, 16c described in the first embodiment are arranged. By detecting, it is possible to determine whether the lightning strikes the tower body 14 or the lightning strikes around the tower body 14.

  The number of magnetic field sensors 16 is 3 to 20, and preferably 3 to 10, from the viewpoints of lightning strike detection accuracy, a configuration for lightning strike detection, cost, and the like. When the number of the magnetic field sensors 16 is two, as will be described later, the detection accuracy when the distance between the lightning strike point and the two magnetic field sensors 16a and 16b is equal decreases. On the other hand, when there are more than 20 magnetic field sensors 16, the configuration of the lightning strike detection device is complicated and the cost for lightning strike detection is undesirably high.

  (8) Therefore, according to the second embodiment, since four or more magnetic field sensors 16 are arranged, the polarity of the output signal of the magnetic field sensor 16 is accurate regardless of whether the lightning strike is around the tower body 14. It can be detected well.

(Reference form)
Hereinafter, the reference embodiment will be described with reference to FIGS. In this reference embodiment, the description overlapping with the first embodiment and the second embodiment is omitted.

In this reference embodiment, a case where two magnetic field sensors 16 are used will be described.
As shown in FIG. 12, a pair of magnetic field sensors 16 (16 a, 16 b) are disposed at positions facing the outer periphery of the lower end of the tower body 180 degrees. When these magnetic field sensors 16a and 16b have a lightning strike at the center x of the tower body 14 of the wind power generation facility 12, the periphery y or the periphery z of the tower body 14, the center x of the tower body 14, the periphery y or the periphery z A magnetic field as an output signal generated by a lightning strike current flowing through each is detected.

  For example, a case where a lightning strike occurs at the center x of the tower body 14 and a case where a lightning strike occurs around the tower body 14 will be described. The waveform of the lightning strike current due to the lightning strike to the tower 14 or the surrounding y is formed as shown in FIG. 13, and immediately after the lightning strike, the current value rises to form a peak, and then the current value gradually decreases.

  As shown in FIG. 14, when a lightning strike occurs in the tower body 14, the magnetic field waveform measured by both magnetic field sensors 16 a and 16 b increases immediately after the lightning strike, and a peak is formed. The value gradually decreases. In other words, in this case, since both the magnetic field sensors 16a and 16b are equidistant from the center x of the tower body 14, the waveform of the magnetic field is similar to the waveform of the lightning current. That is, since the polarities of the magnetic fields measured by the two magnetic field sensors 16a and 16b are the same, it can be determined by the polarity detection circuit 22 that the lightning strikes the tower body 14.

  As shown in FIG. 15, when there is a lightning strike in the vicinity y of the tower body 14, the magnetic field waveform measured by one magnetic field sensor 16 a is increased immediately after the lightning strike, and a peak is formed. Thereafter, the magnetic field value gradually decreases. On the other hand, in the waveform of the magnetic field measured by the other magnetic field sensor 16b, the magnetic field value decreases and a bottom is formed immediately after a lightning strike, and then the magnetic field value gradually increases. That is, in this case, the waveforms of the magnetic fields measured by the two magnetic field sensors 16a and 16b have opposite polarities. Therefore, based on the polarities of the magnetic fields measured by the two magnetic field sensors 16a and 16b, the polarity detection circuit 22 can determine that it is a lightning strike around the tower body 14.

  As shown in FIG. 12, the magnetic field component m1 of the magnetic field sensor 16a has a positive polarity (clockwise in FIG. 12), and the magnetic field component m2 of the magnetic field sensor 16b has a negative polarity (counterclockwise in FIG. 12). Indicates.

  Next, as shown in FIG. 12, a case where a lightning strike has occurred around the tower body 14 is described. In this case, as indicated by a two-dot chain line in FIG. 12, the circumference z of the tower body 14 and the pair of magnetic field sensors 16a and 16b are equidistant, so that measurement is performed by these magnetic field sensors 16a and 16b. The waveform of the magnetic field is the waveform shown in FIG. In other words, the magnetic field waveform obtained by both magnetic field sensors 16a and 16b increases immediately after a lightning strike and forms a peak, and then the magnetic field value gradually decreases. That is, in this case, the polarities of the magnetic field waveforms obtained from the magnetic field sensors 16a and 16b are the same.

  Thus, when the number of the magnetic field sensors 16 is two, in the lightning strike to the periphery of the tower body 14, the same polarity characteristic of the output signal as the case where the tower body 14 has a lightning strike may be shown. This is because the position of the magnetic field sensor 16 and the surrounding lightning strike is such that the line connecting the magnetic field sensor 16a and the surrounding z in FIG. 12 is closer to the tower body 14 side than the tangential direction of the tower body 14 at the magnetic field sensor 16a and the magnetic field sensor 16b. This occurs when the line connecting the periphery z is located closer to the tower body 14 than the tangential direction of the tower body 14 at the magnetic field sensor 16b. Briefly speaking, this occurs when the lightning strike position around the tower body 14 and the magnetic field sensors 16a and 16b are substantially equidistant.

As described above, when there are two magnetic field sensors 16, a false detection may occur in a lightning strike around the tower body 14.
It should be noted that the embodiment described above can be modified and embodied as follows.

-As said magnetic field sensor 16, you may use a Hall element, a magnetoresistive element, etc., for example.
In the first embodiment, the three magnetic field sensors 16a, 16b, and 16c may be provided at positions where the circumferential intervals are not uniform at the lower part of the tower body 14. Further, the magnetic field sensors 16a, 16b, and 16c may be provided at the upper and lower intermediate portions of the tower body 14.

  -As said structure, a power transmission tower, a high-rise building, etc. may be sufficient, for example.

  DESCRIPTION OF SYMBOLS 12 ... Wind power generation equipment as a structure, 14 ... Tower which comprises a structure, 16, 16a, 16b, 16c ... Magnetic field sensor, 22 ... Polarity detection circuit as a discrimination device, 25 ... Integration circuit, 26 ... Double Integration circuit, y, z ... peripheral.

Claims (7)

  Based on the polarity of the output signal waveform, its integrated waveform or its double integrated waveform measured by each magnetic field sensor during a lightning stroke, with 3-20 magnetic field sensors arranged on the outer periphery of the structure subjected to the lightning strike, A lightning strike detector provided with a discriminating device for discriminating whether it is a lightning strike to a structure or a surrounding lightning strike.   The lightning strike detection device according to claim 1, wherein the magnetic field waveform measured by each magnetic field sensor is formed based on a magnetic field component extending in a tangential direction of a circle passing through each magnetic field sensor from the center of the structure.   3. The lightning strike detection device according to claim 1, wherein a polarity detection circuit as a determination device that determines a polarity of a waveform of each magnetic field to be measured is connected to each magnetic field sensor.   The lightning strike detection device according to claim 3, wherein an integration circuit or a double integration circuit is connected to the magnetic field sensor, and the polarity detection circuit is connected to the integration circuit or the double integration circuit. A lightning strike detection method using the lightning strike detection device according to any one of claims 1 to 4,
When the waveform of the output signal measured by each magnetic field sensor, its integrated waveform or its double integrated waveform is the same polarity, it is determined that it is a lightning strike to the structure, and when it is different polarity, A lightning strike detection method for determining that a lightning strike.   The magnetic field waveform as an output signal measured by each magnetic field sensor has the same polarity when the direction of the magnetic field component extending in the tangential direction of the circle passing through the magnetic field sensor from the center of the structure is the same polarity, The lightning strike detection method according to claim 5, wherein a certain case has a different polarity.   The lightning strike detection method according to claim 5 or 6, wherein a waveform capable of determining polarity is selected and discriminated from among the waveform of the output signal, its integrated waveform and its double integrated waveform.

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