JP6628641B2 - Method for estimating charge amount, estimation device, and estimation program - Google Patents

Description

  The present invention relates to a method for estimating a charge amount, an estimating device, and an estimating program. More specifically, the present invention relates to a technique for estimating a charge amount of a lightning strike accompanied by a large charge amount that causes damage to infrastructure facilities on the ground.

  As a conventional method of estimating the amount of lightning charge when a lightning strike occurs, there is known a method of observing a time change of an electric field or a magnetic field caused by a lightning strike on the ground and estimating the height of the lightning charge and the amount of lightning charge (for example, Patent Document 1).

JP 2012-103209 A

  However, the conventional method has a problem in that the estimated charge amount has a large error, and it is not possible to efficiently extract a lightning strike having a charge amount large enough to damage infrastructure on the ground. In order to estimate the charge, it is necessary to know the horizontal position and altitude of the charge in the cloud, but the conventional method has a large estimation error related to this position, so the estimated charge also has a large error. This is because it is not possible to accurately extract only the lightning that can cause damage.

  In addition, a commonly used lightning location system (also called LLS (Lightning Location System)) has a location error of about several hundred meters, and it is difficult to find damaged infrastructure equipment. Is not easy. This means that a distance of several hundred meters is required to climb several mountains if the lightning strike point is a mountainous area, even if the transmission tower is relatively large, even if the distance is relatively large. This is because there are dozens of utility poles in the area where the lightning strikes, and a great deal of effort is required to find out which device has failed due to a lightning strike.

  Due to these issues, the maintenance of infrastructure equipment that has received lightning strikes requires a great deal of labor.In addition, it is statistically possible to determine where lightning strikes with a large amount of electric charge are large enough to damage the equipment. However, there is a problem that it is not possible to take measures such as taking necessary measures based on the judgment made in the above.

  Therefore, an object of the present invention is to provide a charge amount estimating method, an estimating device, and an estimating program capable of accurately estimating a charge amount caused by a lightning strike.

  In the description of the present invention, in order to clarify that the unit is a unit, a symbol or a character as a unit may be described in parentheses.

  In the description of the present invention, the horizontal position on the ground surface (earth) and the sky is defined by a horizontal X direction axis and a horizontal Y direction axis which are set as two axes which are common to each other in a horizontal plane. Let it be represented by two-dimensional coordinates (X, Y). Further, it is assumed that the altitude from the ground surface (the earth) is represented by coordinates (Z) defined by a vertical Z-direction axis which is a vertical direction (the origin and direction of two axes orthogonal to each other in a horizontal plane are Arbitrarily set). Therefore, a position on the ground surface is represented as position coordinates (X, Y, 0), and a position in the sky is represented as position coordinates (X, Y, Z).

Estimation of the amount of charge associated with the lightning discharge is performed using, for example, data obtained by an observation device called a slow antenna. A slow antenna is a measurement device combining an electrostatic antenna and an amplifier for observing a quasi-static electric field (hereinafter referred to as a quasi-static electric field) over a frequency band of less than 1 Hz to several tens of kHz. is there.

A point charge model is often used as a method for estimating the amount of charge neutralized due to a lightning strike. More specifically, the quasi-static electric field change ΔE due to a lightning strike observed by a slow antenna or the like is expressed by Expression 1 using a point charge model. Since the phenomenon that is sufficiently slower than the relaxation time of the charge on the ground is to be analyzed, the ground is treated as a perfect conductor.

In Equation 1, x, y, and z represent distances [m] in the X, Y, and Z directions between an observation device such as a slow antenna and charges in the cloud, respectively, and Q represents a charge amount [C that disappears due to a lightning strike. ]. Further, ε ₀ is a dielectric constant of a vacuum, and π is a circular constant. The position coordinates of the observation equipment such as the slow antenna are known as the installation points.

FIG. 3 shows a conceptual diagram of Expression 1. First, since the ground is considered to be a perfect conductor, the quasi-electrostatic field around the charge in the cloud is, as shown in FIG. 3A, the charge Q (position coordinates: x, y, z) in the cloud. It can be regarded as a quasi-electrostatic field formed by mirror image charges of the same sign (ie, -Q; position coordinates: x, y, -z) having the same magnitude with respect to the ground with the potential V = 0. As a result, the lines of electric force obtained on the ground are perpendicular to the ground as shown in FIG. 3B, and the change in the quasi-electrostatic field can be obtained by observing only the component perpendicular to the ground. Then, from the change ΔE of the quasi-electrostatic field obtained at each observation point (that is, each slow antenna or the like), the charge amount Q [C] is obtained by Expression 1.

FIG. 4 shows a conceptual diagram of each parameter of Expression 1. FIG. 4A is an example of a change waveform of a quasi-electrostatic field observed by a slow antenna, for example. Common lightning strikes in summer are classified as the first lightning strike that creates a new discharge path, followed by subsequent lightning strikes. FIG. 4 (A) shows an example in which several subsequent lightning strikes occur several tens of ms after the first strike. When the first or subsequent lightning strike of negative polarity occurs, the negative charges in the cloud flow into the ground and the negative charges disappear. This is equivalent to the sudden appearance of a positive charge in the air, so that a negative lightning strike changes the quasi-electrostatic field on the surrounding ground plane to positive. Here, the magnitude of the change ΔE of the quasi-electrostatic field shown in FIG. 4 (A) is calculated by using the mathematical expression 1, and the position coordinates (x, y, z) and the charge amount Q. Conversely, since Equation 1 is a function of the four parameters x, y, z, and Q, if the change ΔE of the quasi-electrostatic field is observed at four points shown in FIG. , Y, z) and the amount of charge Q are calculated.

Based on the above, the lightning point (specifically, the position coordinates of the lightning point on the ground surface) is specified, and the altitude of the electric charge in the cloud is specified. The charge amount Q is obtained by substituting the change ΔE of the quasi-electrostatic field thus obtained. Note that x, y, and z in Equation 1 are the distances in the X, Y, and Z directions between the observation device and the charges in the cloud. If the position of the observation device is the origin (0, 0, 0), This is the position coordinates of the charge in the cloud.

Alternatively, by simultaneously observing four or more quasi-electrostatic fields, the position coordinates and the charge amount Q of the charges in the cloud can be obtained by, for example, optimization calculation.

When it is necessary to consider the shape of the ground surface in applying the formula 1, the calculation of the quasi-electrostatic field is performed in advance, and the error is corrected.

The method for estimating the charge amount of the present invention also utilizes the above-described concept of calculating the charge amount. The distance in the horizontal X direction and the distance in the horizontal Y direction between the observation point of the quasi-electrostatic field and the lightning charge, and When the charge amount of the lightning charge is estimated using the distance in the vertical Z direction and the change in the quasi-electrostatic field observed at the observation point, the distance in the horizontal X direction between the observation point and the lightning charge And the distance in the horizontal X direction and the distance in the horizontal Y direction between the observation point and the lightning strike point are used as the distance in the horizontal Y direction, and 20 km from the lightning strike point among the observation points where the change in the quasi-static field is observed. Only the change in the quasi-electrostatic field observed at the distant observation point is used.

In addition, the charge amount estimating apparatus of the present invention measures the distance in the horizontal X direction, the distance in the horizontal Y direction, the distance in the vertical Z direction, and the distance between the observation point of the quasi-electrostatic field and the lightning charge at the observation point. A charge amount estimating unit for estimating the charge amount of the lightning charge using the change in the quasi-static electric field, wherein the charge amount estimating unit includes a distance in the horizontal X direction between the observation point and the lightning charge and a horizontal Y The distance between the observation point and the lightning strike point in the horizontal X direction and the distance in the horizontal Y direction between the observation point and the lightning strike point are used, and among the observation points where the change of the quasi-electrostatic field is observed, the observation point which is more than 20 km away from the lightning strike point Only the change in the quasi-electrostatic field observed at (1) is used.

In addition, the charge amount estimation program of the present invention measures the distance in the horizontal X direction, the distance in the horizontal Y direction, the distance in the vertical Z direction, and the distance between the observation point of the quasi-electrostatic field and the lightning charge, and the observation point. Using the change in the quasi-electrostatic field, the computer is caused to perform a process of estimating the charge amount of the lightning charge, and in the process of estimating the charge amount, the distance in the horizontal X direction between the observation point and the lightning charge and the horizontal with the distance in the horizontal X direction distance and the horizontal Y direction between the lightning point and the observation point as a distance in the Y direction is used, the lightning point of the observation point change in the quasi-electrostatic field has been observed in 20 miles beyond Only the change in the quasi-electrostatic field observed at the observation point is used.

  Therefore, according to the estimation method, the estimation device, and the estimation program for the charge amount, the lightning discharge path is not vertical but is normally inclined, so that the position coordinates of the charge in the cloud in FIG. When (x, y, z), the position coordinates of the lightning point on the ground surface are not usually (x, y, 0), but only the observation data of observation points beyond 20 km is used. Therefore, the influence of the difference between the horizontal position of the electric charge in the cloud and the horizontal position of the lightning point on the ground surface on the estimation of the electric charge is suppressed.

In the method for estimating a charge amount according to the present invention, an altitude at a predetermined temperature in the sky may be used as a distance in the vertical Z direction between the observation point and the lightning charge. In the charge amount estimating apparatus of the present invention, the charge amount estimating unit may use an altitude at a predetermined temperature in the sky as a distance between the observation point and the lightning charge in the vertical Z direction. . The charge amount estimation program according to the present invention is arranged such that, in the process of estimating the charge amount, an altitude at a predetermined temperature in the sky is used as a distance in the vertical Z direction between the observation point and the lightning charge. May be. These cases, the distance in the vertical Z direction between the observation point and the lightning charges so that lightning charge is highly set the specific temperature that is present, for example, quasi-electrostatic field of observation data Thus, the effect of the estimation error in estimating the altitude of the lightning charge on the estimation of the charge amount is avoided.

  According to the charge amount estimation method, the estimation device, and the estimation program of the present invention, it is possible to reduce the influence of the difference between the horizontal position of the charge in the cloud and the horizontal position of the lightning point on the ground surface on the charge amount estimation. Therefore, it is possible to accurately estimate the amount of charge due to the lightning strike.

  According to the charge amount estimation method, the estimation device, and the estimation program of the present invention, it is possible to accurately estimate the charge amount associated with a lightning strike, so that a lightning strike determined based on the magnitude of the charge amount This allows the location of the damaged device to be clearly indicated. In addition, by accumulating these data, it is possible to extract areas with a large amount of charge and areas where lightning strikes are likely to occur on infrastructure facilities.Based on this data, it is possible to determine reasonable lightning protection design and maintenance frequency, etc. Becomes possible.

The charge amount estimating method, the estimating device, and the estimating program according to the present invention are configured such that an altitude at a predetermined temperature in the sky is used as a distance in the vertical Z direction between the observation point and the lightning charge. For example, when estimating the altitude of the lightning electric field based on the observation data of the quasi-electrostatic field, it is possible to avoid the influence of the estimation error on the estimation of the charge amount, and thus more accurately estimate the charge amount due to the lightning strike. It becomes possible to do.

4 is a flowchart illustrating an example of an embodiment of a method for estimating a charge amount according to the present invention. FIG. 4 is a functional block diagram of a charge amount estimating apparatus realized by the charge amount estimation program when the charge amount estimation method of the embodiment is implemented using the charge amount estimation program. It is a figure explaining the quasi-electrostatic field observation required for charge position estimation by a slow antenna. (A) is a diagram for explaining the relationship between the ground and the charge in the cloud and the mirror image charge. (B) is a diagram showing electric lines of force perpendicular to the ground at each observation point. FIG. 3 is a diagram for explaining the concept of each parameter of Expression 1. (A) is a diagram illustrating the concept of ΔE. (B) is a diagram illustrating the concept of x, y, z. FIG. 3 is a diagram illustrating an example of a method of arranging a plurality of observation points (observation devices) and a relation between the observation points and a lightning strike point. FIG. 6 is a diagram (horizontal projection) illustrating the azimuth parameter used for the error in the horizontal direction in the first embodiment. FIG. 4 is a diagram showing a relationship between an average value of the charge amount obtained as a result of the simulation in the first embodiment (100 C if there is no error) and a distance from an observation point to a lightning strike point; FIG. 7 is a diagram showing a relationship when the distance is 2 km. FIG. 4 is a diagram showing a relationship between an average value of the charge amount obtained as a result of the simulation in the first embodiment (100 C if there is no error) and a distance from an observation point to a lightning strike point; FIG. 7 is a diagram showing a relationship when the distance is 3 km. FIG. 4 is a diagram showing a relationship between an average value of the charge amount obtained as a result of the simulation in the first embodiment (100 C if there is no error) and a distance from an observation point to a lightning strike point; FIG. 7 is a diagram showing a relationship when the distance is 5 km. FIG. 4 is a diagram showing a relationship between an average value of the charge amount obtained as a result of the simulation in the first embodiment (100 C if there is no error) and a distance from an observation point to a lightning strike point; FIG. 7 is a diagram showing a relationship when the distance is 8 km. FIG. 9 is a diagram illustrating a relationship between a standard deviation of an error of a charge amount (in the case of a charge amount of 100 C) obtained as a result of the simulation in the first embodiment and a distance from an observation point to a lightning strike point. It is a figure which shows the relationship when (degreeC altitude) is 2 km. FIG. 9 is a diagram illustrating a relationship between a standard deviation of an error of a charge amount (in the case of a charge amount of 100 C) obtained as a result of the simulation in the first embodiment and a distance from an observation point to a lightning strike point. It is a figure which shows the relationship when (degree C altitude) is 3 km. FIG. 9 is a diagram illustrating a relationship between a standard deviation of an error of a charge amount (in the case of a charge amount of 100 C) obtained as a result of the simulation in the first embodiment and a distance from an observation point to a lightning strike point. It is a figure which shows the relationship when (degreeC altitude) is 5 km. FIG. 9 is a diagram illustrating a relationship between a standard deviation of an error of a charge amount (in the case of a charge amount of 100 C) obtained as a result of the simulation in the first embodiment and a distance from an observation point to a lightning strike point. It is a figure which shows the relationship when (degree C altitude) is 8 km.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.

  1 to 4 show an example of an embodiment of a method for estimating a charge amount, an estimating device, and an estimating program according to the present invention.

Quasi method of estimating the charge amount of the present embodiment, the distance in the horizontal X direction distance and the horizontal Y-direction distance and the vertical Z direction between the observation point and the lightning charges of the quasi-electrostatic field, which is observed at the observation point When the charge amount Q of the lightning charge is estimated using the change ΔE of the electrostatic field (S1, S5), the distance in the horizontal X direction and the distance in the horizontal Y direction between the observation point and the lightning charge are calculated. The distance in the horizontal X direction and the distance in the horizontal Y direction between the observation point and the lightning strike point are used (S2), and the altitude at a predetermined temperature in the sky is used as the distance in the vertical Z direction (S3). and, so that only the change ΔE in the quasi-electrostatic field which is observed by the observation point of 20 miles beyond the lightning point of the observation point change ΔE of the quasi-electrostatic field is observed is used (S4) (Fig. 1 reference).

Quasi charge amount estimation apparatus of the present embodiment, the distance in the horizontal X direction distance and the horizontal Y-direction distance and the vertical Z direction between the observation point and the lightning charges of the quasi-electrostatic field, which is observed at the observation point A charge amount estimating unit 11d for estimating the charge amount of the lightning charge using the change in the electrostatic field, and the charge amount estimating unit 11d includes a distance in the horizontal X direction between the observation point and the lightning charge, The distance in the horizontal X direction between the observation point and the lightning strike point and the distance in the horizontal Y direction between the observation point and the lightning strike point are used as the distance in the Y direction, and the observation point at which the change of the quasi-electrostatic field is observed is more than 20 km from the lightning strike point. Only the change in the quasi-electrostatic field observed at the point is used.

  The above-described charge amount estimation method and charge amount estimation device can also be implemented and realized by executing a charge amount estimation program on a computer. Here, a case will be described in which the charge amount estimation method is executed by executing the charge amount estimation program on a computer, and the charge amount estimation device is realized.

  FIG. 2 shows the overall configuration of a computer 10 (which is also the charge amount estimation device 10 in the present embodiment) for executing the charge amount estimation program 17 of the present embodiment.

  The computer 10 (charge amount estimating apparatus 10) includes a control unit 11, a storage unit 12, an input unit 13, a display unit 14, and a memory 15, which are mutually connected by a signal line such as a bus.

  The control unit 11 controls the entire computer 10 and performs calculations related to the estimation of the charge amount according to the charge amount estimation program 17 stored in the storage unit 12, and is, for example, a CPU (Central Processing Unit).

  The storage unit 12 is a device that can store at least data and programs, and is, for example, a hard disk.

  The input unit 13 is an interface (that is, an information input mechanism) for providing at least an operator's command and various information to the control unit 11, and is, for example, a keyboard and a mouse. Note that a plurality of types of interfaces such as both a keyboard and a mouse may be provided as the input unit 13.

  The display unit 14 performs drawing and display of characters, graphics, images, and the like under the control of the control unit 11, and is, for example, a display.

  The memory 15 is a memory space that is a work area when the control unit 11 executes various controls and calculations, and is, for example, a RAM (Random Access Memory).

  Also, the computer 10 can transmit and receive signals such as data and control commands (that is, input and output) to and from the computer 10 as necessary by using a signal line such as a bus or a wide area network line. The data server 18 may be connected.

The control unit 11 of the computer 10 (hereinafter, referred to as the “charge amount estimating device 10”) executes the charge amount estimating program 17 so that the distance between the observation point of the quasi-electrostatic field and the lightning charge is increased. A horizontal position setting unit 11a for setting the horizontal X-direction distance and horizontal Y-direction distance to the horizontal X-direction distance and the horizontal Y-direction distance between the observation point and the lightning strike point; An altitude setting unit 11b for performing a process of setting a distance in the vertical Z direction between the electric charge and an altitude of a specific temperature at which a lightning charge is assumed to exist, and a horizontal distance between a lightning strike point and an observation point is 20 km or more. A data selection unit 11c that performs a process of extracting the observation point that is set as described above, a distance in the horizontal X direction, a distance in the horizontal Y direction, and a distance in the vertical Z direction between the observation point and the lightning charge; Observed at the observation point extracted by By using the change of the quasi-electrostatic field, the charge amount estimation unit 11d and is configured to perform the processing for estimating the amount of charge of the lightning charges.

Then, as a procedure for implementing the method for estimating the charge amount, first, a quasi-static field is observed (S1).

The observation of the quasi-electrostatic field as the processing of S1 is performed to detect a time change of the quasi-electrostatic field due to a lightning strike.

Observation of the quasi-electrostatic field is performed using, for example, an observation device called a slow antenna. Specifically, for example, it may be performed by a lightning strike position locating system (also called LLS).

Observation of the quasi-electrostatic field is performed, for example, at a plurality of observation points, in other words, by a plurality of observation devices separately installed. The number of observation points and the interval between observation points are not limited to specific numbers and intervals. For example, the sensitivity of observation equipment (that is, the range in which the quasi-electrostatic field change due to lightning can be observed) is taken into consideration. The number and interval are appropriately set, taking into account the number and interval required to cover the range in which lightning detection and estimation of the amount of charge associated with lightning are required. You.

Specifically, for example, as an example only, the sensitivity of the observation device is such that the horizontal distance at which the quasi-electrostatic field change accompanying the electric charge of 200 C existing at an altitude of 5 km can be observed is 40 km at the maximum. As shown in FIG. 5, a plurality of observation points 1A to 1E are arranged so as to form a triangular grid with an interval of about 50 km (in other words, at the intersection (vertex) position of the triangular grid). Can be considered. Of course, only the observation points 1A, 1B, and 1C among the observation points shown in FIG. 5 may be arranged and only one triangle observation area may be set, or more triangle observation areas may be set. May be set continuously.

  The horizontal position of each observation point is, for example, the position of an installation point of observation equipment such as a slow antenna and is known. The position coordinate data relating to the horizontal position of each observation point is, for example, a data file in which combination data of an identifier for each observation point and the horizontal position coordinates (xo, yo) of the observation point is recorded as the storage unit 12 or the data server. 18 and so on.

Results of the observation of the quasi-electrostatic field, a predetermined frequency band (e.g., less than several Hz of frequency bands) are organized as data capable of grasping the time variation of the quasi-electrostatic field at, for specifically, for example, quasi-electrostatic field change waveform Organized as time-series data.

Observation data as an observation result of the quasi-electrostatic field is stored in, for example, the storage unit 12 or the data server 18 as a data file for each observation point.

  In addition, the processing after S2 may be performed immediately (in other words, every time a lightning strike occurs), for example, triggered by detection of a lightning strike at an observation point, or may be performed over a predetermined period. After the observation data is stored, the observation data for the predetermined period may be collectively performed.

It should be noted that the method of detecting the occurrence of a lightning strike is not an important point in the present invention, and an existing or new technique capable of detecting the occurrence of a lightning strike based on, for example, the shape of a radiation electromagnetic field change waveform can be used. In addition, since the time of occurrence of a lightning strike can usually be specified when detecting the occurrence of a lightning strike, the present invention assumes that the time of occurrence of a lightning strike is known.

  Next, the horizontal position of the lightning charge is set (S2).

  As the horizontal position of the lightning charge (specifically, the horizontal position coordinates xc, yc of the charge existing in the cloud above the sky (also referred to as “lightning charge”)), the horizontal position of the lightning strike point (that is, the lightning strike point on the ground surface) The horizontal position coordinates (xl, yl) are used. Therefore, the setting of the horizontal position of the lightning charge as the process of S2 is performed by specifying the horizontal position of the lightning strike point.

The setting of the horizontal position of the lightning charge (in other words, the specification of the horizontal position of the lightning strike point) is performed, for example, by observing the observation point that observed the situation corresponding to the lightning strike (specifically, for example, the time change of the radiated electromagnetic field ). This is performed using data.

  Specifically, the horizontal position of the lightning strike point can be specified, for example, by applying the arrival time difference method or the resection method to observation data obtained by the lightning strike location system (LLS) (for example, Saito Mikihisa et al., "Basic Study for Development of New Lightning Lightning Location System (New LLS) (1)-Analysis of Factors of Location Error-", Central Research Institute of Electric Power Industry Research Report H14007, 2015).

The arrival time difference method is a method of locating the radiated electromagnetic field signals simultaneously observed at three or more observation points, assuming that the intersection of the hyperbolas drawn from the time difference between each of the two selected observation points is the lightning strike point. It is. Note that the arrival time difference method has an advantage that the error is relatively small because the measurement of the electromagnetic wave arrival time at the observation point is hardly affected by surrounding obstacles and terrain.

  The resection method receives a magnetic field signal generated by a lightning discharge with a quadrature loop antenna, calculates the direction of the horizontal magnetic field, estimates the direction of arrival of the electromagnetic wave, and calculates the direction at two or more observation points. This is a method for locating the lightning discharge by the method. Note that the resection method has an advantage in that the position can be located if effective data is observed at two or more observation points.

  However, the setting of the horizontal position of the lightning charge (in other words, the specification of the horizontal position of the lightning strike point) is not limited to a specific method in the present invention, but specifies the horizontal position coordinates of the lightning strike point on the ground surface. Any method may be used as long as it can be obtained.

  In the present embodiment, the horizontal position setting unit 11a of the control unit 11 uses the information necessary for specifying the horizontal position coordinates of the lightning strike point on the ground surface (for example, observation data stored in the storage unit 12, the data server 18, or the like). Is read, and the horizontal position of the lightning strike point (specifically, the position coordinate xl in the horizontal X direction and the position coordinate yl in the horizontal Y direction) are specified.

  Then, the horizontal position coordinates (xl, yl) of the specified lightning strike point are stored in the memory 15 as the horizontal position coordinates (xc, yc) of the lightning charge by the horizontal position setting unit 11a.

  Next, the altitude of the lightning charge is set (S3).

  The altitude of lightning charge is a specific temperature in various weather data, high-rise observation data, etc., utilizing the knowledge that lightning charge exists in a specific temperature region in the cloud (in other words, altitude layer). Set to the altitude of the area.

  The specific temperature at which a lightning charge is assumed is appropriately set based on existing or new analysis results. Specifically, for example, the altitude of the lightning charge is set to an altitude of −10 ° C. in weather data or the like (for example, Masaru Ishii et al. “Positive winter lightning discharge with large current”, IEEJ High Voltage Research meeting material HV-06-47, 2006).

  As weather data, high-rise observation data, etc. for specifying the altitude of a specific temperature at which a lightning charge is present (referred to as “lightning charge height identification data”), specifically, for example, only as an example, Data called GPV (short for Grid Point Value) created by the Japan Meteorological Agency may be used.

  The lightning charge altitude specifying data is stored in the storage unit 12, the data server 18, or the like, for example, as a data file in which a combination data of the observation date and time and the temperature for each altitude is recorded.

  Specifically, the altitude of the lightning charge is set, for example, at an altitude above the lightning strike point at which the temperature is at a specific temperature (specifically, for example, −10 ° C.) at the time of the lightning strike. The altitude is set to the altitude of the lightning charge.

  In the present embodiment, the altitude setting unit 11b of the control unit 11 reads the lightning charge altitude specifying data stored in the storage unit 12, the data server 18, and the like, and also stores the lightning charge altitude stored in the memory 15 in the process of S2. The horizontal position coordinates (xc, yc) of the electric charge are read, and the charge altitude specifying data at the lightning strike occurrence time regarding the horizontal position of the lightning charge (in other words, above the horizontal position of the lightning strike point) is read.

  Then, the altitude setting unit 11b specifies the altitude z at which a specific temperature (specifically, for example, −10 ° C.) is reached, and the altitude z is stored in the memory 15 as the altitude zc of the lightning charge.

  The value of the specific temperature at which the lightning charge is present may be input by the operator via the input unit 13 or may be specified in advance in the charge amount estimation program 17. May be.

Next, observation data of the quasi-electrostatic field is selected (S4).

In the present invention, the charge amount of the lightning charge is estimated using only the observation data (specifically, the change ΔE of the quasi-electrostatic field) of the observation point located 20 km or more from the lightning strike point. For this reason, an observation point that is located more than 20 km from the lightning strike point is extracted from the observation points that observe the situation corresponding to the lightning strike (specifically, for example, a time change of the quasi-static field).

  Specifically, in the present embodiment, the horizontal position coordinates (xl) of the lightning strike point stored in the memory 15 as the horizontal position coordinates (xc, yc) of the lightning charge in the process of S2 by the data selection unit 11c of the control unit 11. , Yl) is read, and data on the horizontal position coordinates (xo, yo) of each observation point stored in the storage unit 12, the data server 18, or the like is read.

  Then, the horizontal distance between the lightning strike point and each observation point is calculated by the data selection unit 11c, and the observation point whose horizontal distance is equal to or more than 20 km is extracted.

  A specific example of the observation point extraction (in other words, selection) will be described with reference to FIG. 5 showing an example of a method of arranging a plurality of observation points (observation devices). In FIG. 5, a dashed line denoted by reference numeral 2 indicates a boundary at a distance of 20 km from each of the observation points 1A to 1E.

  When the position of reference numeral 4A in FIG. 5 is a lightning strike point, since the distance from the observation point 1A is within the boundary circle of 20 km, the observation point 1A is not extracted, and the observation points 1B and 1C are not extracted. Is extracted.

  In the arrangement example shown in FIG. 5, it is assumed that the maximum observable distance between the observation points 1A to 1E is 40 km. Since the lightning strike point 4A is included in the observable range of the observation point 1B and the observation point 1C, the observation points 1B and 1C are extracted. However, if the maximum observable distance is longer, the observation points 1D and 1E are also extracted.

  On the other hand, when the position of reference numeral 4B in FIG. 5 is a lightning strike point, the distance from each of the observation points 1A to 1E is not included in any of the 20 km-boundary circles. 1B and an observation point 1D are extracted. If the maximum observable distance is long, the observation point 1C is also extracted.

  In the present invention, since the lightning discharge path is not vertical but inclined normally, the lightning strike on the ground surface occurs when the position coordinates of the charges in the cloud are (x, y, z) in FIG. The position coordinates of the point are such that only the observation data of the observation point located more than 20 km from the lightning strike point is used in order to suppress the error caused by the fact that it is not usually (x, y, 0). It is preferable that only observation data at observation points as far as possible from the lightning strike point (that is, as far as the observation sensitivity of the observation point allows) is used. At this point, the distance as a reference for extracting (in other words, selecting) an observation point is not limited to 20 km, but may be set to 25 km.

  In the present embodiment, the identifier of the observation point (referred to as “selected observation point”) whose horizontal distance from the lightning strike point is 20 km or more is stored in the memory 15 by the data selection unit 11c.

  Next, the charge amount is estimated (S5).

  Specifically, first, the identifier of the selected observation point stored in the memory 15 in the process of S4 is read by the charge amount estimation unit 11d.

  Subsequently, the horizontal position coordinates (xl, yl) of the lightning strike point stored in the memory 15 as the horizontal position coordinates (xc, yc) of the lightning charge in the process of S2 are read by the charge amount estimation unit 11d, and the storage unit Data about the horizontal position coordinates (xo, yo) of the selected observation point is read from the data about the horizontal position coordinates (xo, yo) of each observation point stored in the data server 12 or the data server 18 and the like. The horizontal distance dx in the X direction and the horizontal distance dy in the Y direction between the and the observation point are calculated.

  The charge amount estimating unit 11d reads the altitude zc of the lightning charge stored in the memory 15 in the process of S3.

The charge amount estimating unit 11d further reads the observation data (specifically, the quasi-electrostatic field change ΔE) of the selected observation point from the observation data stored in the storage unit 12, the data server 18, and the like.

  Then, the charge amount estimating unit 11d substitutes the above data (specifically, the values of dx, dy, zc, and ΔE regarding the selected observation point in the process of S4) into Expression 2, and the charge amount Q is calculated. Is calculated. Expression 2 is an expression obtained by solving Expression 1 for the charge amount Q.

  Here, when there is only one selected observation point, the charge amount Q calculated using each data item regarding the one selected observation point is used as the estimation result.

On the other hand, when the number of selected observation points is two or more, as a method of determining the final estimation result, for example, the following methods a to c are cited.
A) Of the plurality of selected observation points, the charge amount Q calculated using each data of the selected observation point having the longest horizontal distance to the lightning strike point (that is, the furthest from the lightning strike point) is finalized. It is the estimation result.
B) The average value of the charge amount Q for each of the plurality of selected observation points calculated using the data for each of the plurality of selected observation points is used as the final estimation result.
C) When the number of the selected observation points is three or more, the minimum value of the charge amount Q for each of the three or more selected observation points calculated by using the data on each of the three or more selected observation points. The remaining average value excluding and the maximum value is used as the final estimation result.

  Then, the control unit 11 displays the value of the charge amount Q as the estimation result on the display unit 14 or saves the value as a data file in the storage unit 12, and then performs a process related to the estimation of the charge amount related to the lightning strike. finish.

  According to the charge amount estimating method, the estimating device, and the estimating program configured as described above, the lightning discharge path is not inclined in the vertical direction but is usually inclined, so that the position coordinates of the lightning charge are (xc, yc, When zc), the position coordinates of the lightning strike point on the ground surface are not usually (xc, yc, 0), but only the observation data of the observation points beyond 20 km (or 25 km) are used. , The effect of the difference between the horizontal position of the lightning charge and the horizontal position of the lightning point on the ground surface on the estimation of the charge amount can be reduced, and therefore, the charge amount associated with the lightning strike can be accurately estimated. It becomes possible.

  Although the above-described embodiment is an example of a preferred embodiment for carrying out the present invention, the embodiment of the present invention is not limited to the above-described embodiment, and the present invention is not limited thereto without departing from the gist of the present invention. The invention can be variously modified.

That is, the gist of the present invention is that, when the amount of charge due to lightning (in other words, the amount of lightning charge) is estimated, it is observed at an observation point 20 km or more (or 25 km or more) from the lightning point. The data (specifically, the time change of the quasi-electrostatic field) is used, and the other processing content is that if the data necessary for calculating the charge amount Q by Formula 1 or Formula 2 is available, The present invention is not limited to the contents described as the processing of S1 to S5.

For example, although in the embodiment described above are mentioned slow antenna and lightning location system as an example of a mechanism used in observation (S1) of the quasi-electrostatic field, the mechanisms used in the observation of the quasi-electrostatic field, lightning The present invention is not limited to the slow antenna and the lightning strike position locating system exemplified in the above-described embodiment as long as the time change of the quasi-electrostatic field due to the above can be grasped.

  In the above-described embodiment, the lightning strike position locating system is given as an example of the mechanism used in setting the horizontal position of the lightning charge (S2). However, the mechanism used in setting the horizontal position of the lightning charge is as follows. As long as the horizontal position coordinates (xl, yl) of the lightning strike point can be specified, the present invention is not limited to the lightning strike position locating system described as an example in the above embodiment.

  Further, in the above-described embodiment, the altitude of the lightning charge is set to the altitude of a region in the sky where the specific temperature at which the lightning charge is assumed to be present in the process of S3. The setting method is not limited to the method in the above embodiment as long as the altitude of the lightning charge can be specified (set). Specifically, for example, data obtained as a result of radar observation and data obtained as a result of observation using electromagnetic waves in the VHF band are used to determine the altitude of the lightning charge in the cloud, and the altitude of the lightning to the specified altitude is determined. The height of the charge may be set.

Equation 2 used for estimating the amount of charge in the process of S5 in the above embodiment is the horizontal distance dx and Y in the X direction between the lightning charge (position coordinates are unknown) and the observation point (position coordinates are known). Since the horizontal distance dy in the direction, the altitude zc of the lightning charge, and the charge amount Q are functions of four parameters, if the quasi-electrostatic field change ΔE is observed at four or more observation points, the position coordinates (xc , Yc, zc) and the parameters of the charge Q can be calculated. Therefore, when the quasi-electrostatic field change ΔE is observed at four or more observation points, the position coordinates (xc, yc, zc) of the lightning charge are calculated using the observation data, and based on the calculation result. An observation point (or a selected observation point) 20 km or more (or 25 km or more) from the lightning strike point is extracted, and the quasi-electrostatic field change ΔE observed at the selected observation point is used to calculate the charge amount Q according to Expression 2. It may be calculated again. In this case, as the altitude zc of the lightning charge, the value of zc calculated using the observation data may be used, or it is assumed that the lightning charge exists as in the above-described embodiment. An altitude at a specific temperature may be used.

  An example of evaluating the error of the estimated value of the charge amount for verifying the validity of the method of estimating the charge amount according to the present invention will be described with reference to FIGS.

In this embodiment, specifically, when the quasi-electrostatic field changes the amount of charge if the assumption that there is no specific position error of the lightning charges are estimated to be 100 C was observed (i.e., quasi The static electric field change was assumed to be constant), however, due to the specific error of the position of the lightning charge, it was evaluated how much C lightning strike actually caused the quasi-static electric field change. .

  Since the displacement of the position of the lightning charge is added in both the horizontal direction and the vertical direction, each displacement is given by a random number and evaluated by Monte Carlo simulation.

  When the horizontal deviation is compared with the content (procedure) of the processing of S2 in the above-described embodiment, the horizontal displacement of the lightning point located (specified) based on the observation data obtained by the lightning location system (LLS) is described. The difference between the position and the horizontal position of the lightning charge.

  When the vertical displacement is compared with the content (procedure) of the processing of S3 in the above-described embodiment, the altitude at a specific temperature at which lightning charges are assumed to exist (specifically, the altitude at −10 ° C. in the sky). And the altitude of the lightning charge.

  As for the width of the shift, the shift in the horizontal direction was uniformly distributed in a range of ± 6 km, and the shift in the vertical direction was uniformly distributed in a range of ± 1 km. Further, since the azimuth of the deviation in the horizontal direction is also one parameter, the parameter of the azimuth θ as shown in FIG. 6 is considered, and the azimuth of the deviation is uniformly distributed in the range of 0 to 2π rad.

  Then, the displacement (xc, yc, zc) of the position of the lightning charge is set based on the result of generating the azimuth θ of the horizontal displacement, the vertical displacement, and the horizontal displacement 10,000 times with random numbers without correlation. A Monte Carlo simulation of calculating the amount of charge was performed. The position (xc, yc, zc) of the lightning charge is a position coordinate when the position of the virtual observation point is set to the origin (0, 0, 0).

  For calculation of the charge amount, Expression 3 which is a formula obtained by solving Expression 1 for the charge amount Q was used.

In the simulation, since the quasi-electrostatic field change ΔE was constant as described above, the position (xc, yc, zc) of the lightning charge was shifted and changed.

The quasi-electrostatic field change ΔE has no vertical / horizontal position shift (that is, when the horizontal position of the lightning charge is directly above the lightning strike point and the height of the lightning charge is the same as the altitude of -10 ° C). Is a calculation result when the quasi-electrostatic field strength is such that a lightning charge having a charge amount of 100 C exists.

  A simulation is performed at each altitude where lightning charge is assumed to exist, and the results shown in FIGS. 7A to 7D are obtained for the average value of the estimated charge amount, and FIG. 8A shows the standard deviation of the estimated charge amount. 8D were obtained.

  7A to 7D and FIGS. 8A to 8D, when the height of the electric charge is 2 km, the influence of the displacement of the lightning charge is remarkable, and the horizontal distance between the observation point and the lightning strike point is 20 km. Below, there is an error of about 20 C (that is, 20% because there is no error, 100 C) with respect to the average value, and 50 C (that is, 100 C, where there is no error) with respect to the standard deviation. %) Or more.

  From the results shown in FIGS. 7A to 7D and FIGS. 8A to 8D, when the horizontal distance between the observation point and the lightning point is less than 20 km, the error in the estimated charge amount is large. It was confirmed that the charge amount can be estimated with high accuracy by using the data, and that the charge amount can be estimated with higher accuracy by using only the data separated by 25 km or more.

  The method for estimating the amount of charge, the estimation device, and the estimation program according to the present invention can accurately estimate the amount of charge associated with a lightning strike. It has high utility value in fields such as power distribution.

S1 Observation of quasi-electrostatic field S2 Setting of horizontal position of lightning charge S3 Setting of altitude of lightning charge S4 Selection of observation data of quasi-static electric field S5 Estimation of charge amount 10 Estimation device of charge amount 17 Estimation program of charge amount

Claims (6)

The distance in the horizontal X direction, the distance in the horizontal Y direction, the distance in the vertical Z direction between the observation point of the quasi-static field and the lightning charge, and the change in the quasi-electrostatic field observed at the observation point are used. When the charge amount of the lightning charge is estimated, a horizontal distance between the observation point and the lightning point is defined as a distance in the horizontal X direction and a distance in the horizontal Y direction between the observation point and the lightning charge. with the distance in the X direction of the distance and horizontal Y direction is used, the quasi electrostatic field changes observed the from the lightning strike point of the observation point 20 miles beyond the observed at the observation point was of the quasi-electrostatic field of A method for estimating a charge amount, wherein only a change is used.   2. The method according to claim 1, wherein an altitude at a predetermined temperature in the sky is used as the distance between the observation point and the lightning charge in the vertical Z direction. Using the distance in the horizontal X direction and the distance in the horizontal Y direction and the distance in the vertical Z direction between the observation point of the quasi-static field and the lightning charge, and the change in the quasi-electrostatic field observed at the observation point, A charge amount estimating unit for estimating a charge amount of the lightning charge, wherein the charge amount estimating unit calculates the distance in the horizontal X direction and the distance in the horizontal Y direction between the observation point and the lightning charge. The distance in the horizontal X direction and the distance in the horizontal Y direction between the observation point and the lightning strike point is used, and the observation point at least 20 km away from the lightning strike point among the observation points where the change of the quasi-static field is observed. A charge amount estimating apparatus using only the change in the quasi-electrostatic field observed in (1).   The charge amount estimating unit according to claim 3, wherein the charge amount estimating unit uses an altitude at a predetermined temperature in the sky as the distance in the vertical Z direction between the observation point and the lightning charge. Estimation device. Using the distance in the horizontal X direction and the distance in the horizontal Y direction and the distance in the vertical Z direction between the observation point of the quasi-static field and the lightning charge, and the change in the quasi-electrostatic field observed at the observation point, The computer performs a process of estimating the charge amount of the lightning charge, and in the process of estimating the charge amount, the distance in the horizontal X direction and the distance in the horizontal Y direction between the observation point and the lightning charge. The distance in the horizontal X direction and the distance in the horizontal Y direction between the observation point and the lightning strike point are used, and among the observation points where the change of the quasi-static field is observed, the distance of 20 km or more from the lightning strike point A charge amount estimating program, wherein only a change in the quasi-electrostatic field observed at an observation point is used.   The altitude at which a predetermined temperature is obtained in the sky is used as the distance in the vertical Z direction between the observation point and the lightning charge in the processing of estimating the charge amount. Charge estimation program.

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