JP6573330B2 - Coulomb amount measuring device - Google Patents

Description

  The present invention relates to a coulomb amount measuring apparatus that measures the amount of coulomb during a lightning strike on an object.

  For example, there is a device that detects a surge current that flows through a structure due to a lightning strike when a lightning strike occurs on a structure such as a windmill tower or a power transmission tower of a wind power generation system (see, for example, Patent Document 1).

  The simple surge current detector disclosed in Patent Document 1 has a configuration in which a current sensor such as a CT (current transformer) or a Rogowski coil is attached to a structure such as a windmill tower or a power transmission tower.

  In this simple surge current detector, the current sensor detects the surge current that flows through the structure during a lightning strike on the structure, and manages the level information, propagation direction information, and time information of the surge current based on the detection signal. ing.

  When measuring the amount of coulomb during a lightning strike using such a current sensor, the area of the current waveform is calculated based on the current waveform of the detection signal output from the current sensor. Can be obtained.

JP 2008-96336 A

  By the way, in the simple surge current detector disclosed in Patent Document 1, a current sensor such as a CT (current transformer) or a Rogowski coil is used to detect a surge current flowing through the structure during a lightning strike.

  However, a current sensor such as a CT (current transformer) or a Rogowski coil needs to be attached so as to surround a structure such as a windmill tower or a power transmission tower.

  As a result, it is necessary to prepare a plurality of types of current sensors according to the size of the structure, and it is difficult to respond quickly to changes in the structure. In addition, when the structure becomes large, the current sensor must be increased in size, resulting in an increase in cost. Furthermore, the current sensor becomes a heavy object, and handling at the time of installation on the structure becomes difficult.

  In the case of a current sensor, if the duration of the surge current is long, the current sensor coil itself is magnetically saturated. When such magnetic saturation occurs, the amount of coulomb obtained by calculating the area of the current waveform of the detection signal can be obtained only until the time when the current sensor is magnetically saturated. As a result, it becomes difficult to accurately measure the coulomb amount.

  Therefore, the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is a small size capable of quickly responding to a change in the structure and capable of measuring the coulomb amount at the time of lightning with high accuracy. It is to provide an inexpensive coulomb amount measuring device.

As a technical means for achieving the above-mentioned object, a coulomb amount measuring device according to the present invention is arranged in the vicinity of an object and a Hall element that detects a magnetic field generated by a lightning strike on the object. A magnetic field sensor connected to the output of the Hall element and an amplifier for amplifying the detection signal output from the Hall element, and connected to the output of the magnetic field sensor to generate a voltage waveform of the detection signal output from the amplifier. A controller that calculates the amount of coulomb at the time of lightning strike on the object, and the controller is set and inputted with the size of the object and the separation distance between the object and the Hall element It is characterized by.

  In the coulomb amount measuring device of the present invention, a Hall element is used as a magnetic field sensor. As described above, by using the Hall element, it is not necessary to attach the object to surround the object as in the conventional current sensor, and it is only necessary to arrange the Hall element close to the object.

  As a result, it becomes easy to quickly respond to the change of the structure, and even if the structure becomes large, a small Hall element can be used, and the cost of the apparatus can be reduced. Moreover, the use at the time of installation to a structure becomes easy by using a small Hall element.

  The magnetic field sensor according to the present invention can have a structure in which a plurality of Hall elements are arranged at the same distance from the object, and an amplifier is connected to the output of each Hall element so that the amplification factor of each amplifier is different. It is.

  As another structure, it is possible to arrange a single Hall element with respect to an object and connect a plurality of amplifiers having different amplification factors to the output of the Hall element.

  Furthermore, as another structure, a plurality of Hall elements can be arranged at different distances from the object, and an amplifier can be connected to the output of each Hall element so that the amplification factor of each amplifier is the same. It is.

  By adopting the configuration as described above, the controller selects the optimum amplifier output according to the magnitude of the magnetic field generated by lightning strikes, and adds up the outputs of these amplifiers to approximate the current waveform of the lightning surge. By calculating the area of the voltage waveform, the coulomb amount can be calculated with high accuracy.

  According to the present invention, by using a Hall element as a magnetic field sensor, it is not necessary to surround the object as in the case of a conventional current sensor, and only the Hall element is arranged close to the object. That's it.

  As a result, it becomes easy to quickly respond to the change of the structure, and even if the structure becomes large, a small Hall element can be used, and the cost of the apparatus can be reduced. Moreover, the use at the time of installation to a structure becomes easy by using a small Hall element.

1 is a circuit block diagram illustrating a schematic configuration of a coulomb amount measuring device according to an embodiment of the present invention. It is a circuit block diagram which shows schematic structure of the coulomb amount measuring device in other embodiment of this invention. It is a wave form diagram for demonstrating the operation example of the coulomb amount measuring apparatus of FIG. 1 and FIG. (A) is a wave form diagram which shows the measurable area | region by the conventional Rogowski coil, (B) is a wave form diagram which shows the measurable area | region by the Hall element of this invention. It is a circuit block diagram which shows schematic structure of the coulomb amount measuring device in other embodiment of this invention. It is a perspective view which shows the example which installed the coulomb amount measuring device in each embodiment of this invention in the windmill tower.

  An embodiment of a coulomb amount measuring device according to the present invention will be described below in detail with reference to the drawings. In the following embodiment, as illustrated in FIG. 6, a case where a coulomb amount measuring device 12 is installed in a wind turbine tower 11 of a wind power generation system is illustrated, but this coulomb amount measuring device 12 may be another type such as a power transmission tower. It can also be installed on structures.

  As shown in FIG. 1, the coulomb amount measuring device 12 of this embodiment includes a plurality (four in the figure) of Hall elements 13 arranged close to a wind turbine tower 11 (see FIG. 6) that is an object. And a magnetic field sensor 15 composed of a plurality (four in the figure) of amplifiers 14 connected to the output of each Hall element 13, and a controller 16 connected to the output of the magnetic field sensor 15.

  The Hall element 13 and the controller 16 of the magnetic field sensor 15 are supplied with a driving voltage by a power source 17. In this embodiment, four Hall elements 13 and amplifiers 14 are exemplified, but the number may be other than four and the number is arbitrary.

  The hall element 13 of the magnetic field sensor 15 detects a magnetic field generated by a lightning strike on the windmill tower 11. The amplifier 14 of the magnetic field sensor 15 amplifies the detection signal output from the Hall element 13 with a predetermined amplification factor. The four amplifiers 14 in this embodiment have different amplification factors. The controller 16 calculates the amount of coulomb during a lightning strike to the wind turbine tower 11 based on the voltage waveform of the detection signal output from the amplifier 14 of the magnetic field sensor 15.

  The controller 16 is connected to the A / D converter 18 connected to the output of the amplifier 14 of the magnetic field sensor 15, the memory 19 connected to the output of each A / D converter 18, and the output of each memory 19. And the arithmetic unit 20. The controller 16 includes the same number of A / D converters 18 and memories 19 as the Hall elements 13 and amplifiers 14 of the magnetic field sensor 15.

  The A / D converter 18 of the controller 16 digitally converts the analog detection signal output from the amplifier 14 of the magnetic field sensor 15. The memory 19 of the controller 16 stores the detection signal digitally converted by the A / D converter 18 as data. The computing unit 20 of the controller 16 calculates the amount of coulomb at the time of lightning strike to the windmill tower 11 based on the voltage waveform of the detection signal stored in the memory 19.

  A display unit 21, a signal unit 22, and a transmission unit 23 are connected to the output of the calculation unit 20 of the controller 16. The display unit 21 displays the coulomb amount and time calculated by the calculation unit 20 as a history. The transmission unit 23 transmits the coulomb amount and time calculated by the calculation unit 20 to a remote location via the Internet or the like.

  The signal unit 22 outputs a voltage contact signal when, for example, a predetermined amount of coulomb is calculated. For example, by connecting the signal unit 22 to the relay circuit of the wind power generation system, when the coulomb amount exceeds a predetermined value, a voltage contact signal is output to the relay circuit, so that the operation of the wind power generation system can be safely performed. Can be stopped. Thereby, damage to the windmill due to lightning strikes can be prevented, and for example, a serious accident in which the blades of the windmill are scattered can be prevented.

  Here, the output voltage of the magnetic field sensor 15 varies depending on the magnitude of the magnetic field. Therefore, the magnitude of the magnetic field varies depending on the size (outer diameter) of the windmill tower 11 through which the surge current flows and the separation distance between the windmill tower 11 and the Hall element 13, and the output voltage of the Hall element 13 varies.

  Accordingly, the coulomb amount can be appropriately corrected by inputting the size of the windmill tower 11 and the separation distance between the windmill tower 11 and the hall element 13 in advance to the calculation unit 20 of the controller 16. .

  In the coulomb amount measuring device 12 of the embodiment shown in FIG. 1, the magnetic field sensor 15 in which a plurality of Hall elements 13 are incorporated is illustrated, but the present invention is not limited to this, and the embodiment of the embodiment shown in FIG. Thus, the magnetic field sensor 15 in which the single Hall element 13 is incorporated may be used. In FIG. 2, the same parts as those in FIG.

  The coulomb amount measuring device 12 of the embodiment shown in FIG. 2 has a structure in which the output of a single Hall element 13 is input-connected to each of a plurality (four) of amplifiers 14. The four amplifiers 14 in this embodiment have different amplification factors as in the embodiment of FIG.

  In the coulomb amount measuring device 12 (see FIGS. 1 and 2) configured as described above, the coulomb amount at the time of lightning strike to the wind turbine tower 11 is measured in the following manner.

  First, prior to measuring the coulomb amount, the coulomb amount measuring device 12 is installed on the wind turbine tower 11 (see FIG. 6). The coulomb amount measuring device 12 is attached to the wind turbine tower 11 by using an appropriate means such as a mounting bracket.

  In the coulomb amount measuring device 12 of this embodiment, by using the Hall element 13 as the magnetic field sensor 15, it is not necessary to mount the Hall element 13 so as to surround the windmill tower 11 unlike the conventional current sensor, and the Hall element 13 is attached to the windmill tower 11. You just need to be close to

  As a result, it becomes easy to quickly respond to the change of the structure, for example, the application to the wind turbine tower 11 having a different outer diameter or the power transmission tower, and the small hall element 13 is used even if the structure becomes large. The cost of the apparatus can be reduced. In addition, the use of the small Hall element 13 facilitates the handling during installation on the structure.

  In the magnetic field sensor 15 of the coulomb measuring device 12 attached to the windmill tower 11 as described above, when a surge current flows through the windmill tower 11 due to a lightning strike on the windmill tower 11 (see arrows in FIGS. 1 and 2), The Hall element 13 detects the magnetic field from the surge current. The detection signal (voltage) output from the hall element 13 is amplified by the amplifier 14 with a predetermined amplification factor.

  The controller 16 of the coulomb amount measuring device 12 calculates the coulomb amount at the time of lightning strike to the wind turbine tower 11 based on the voltage waveform of the detection signal output from the amplifier 14 of the magnetic field sensor 15. That is, the analog detection signal output from the amplifier 14 is digitally converted by the A / D converter 18. The detection signal digitally converted by the A / D converter 18 is stored in the memory 19 as data. Based on the voltage waveform of the detection signal stored in the memory 19, the arithmetic unit 20 calculates the amount of coulomb during a lightning strike on the windmill tower 11.

  In the coulomb amount measuring device 12 of this embodiment, a magnetic field sensor 15 including four amplifiers 14 having different amplification factors is used. As described above, by using the four amplifiers 14 having different amplification factors, the calculation unit 20 of the controller 16 selects the optimum output of the amplifier 14 in accordance with the magnitude of the magnetic field generated by the lightning strike. Add 14 outputs together.

  That is, with respect to the current waveform of the lightning surge, there are four different amplification factors in the detected voltage (voltage waveform) stored in the memory 19 as shown in FIG. 3 according to the magnitude of the current value in the current waveform. The maximum voltage in the measurement ranges A to D set by the amplifier 14 is discriminated every time, and the optimum output voltage of the amplifier 14 is selected.

  Here, if the amplification factors of the four amplifiers 14 are, for example, 10 times, 50 times, 100 times, and 1000 times, the amplifier 14 having the amplification rate of 10 times is selected in the region a (measurement range A) of the voltage waveform. In the b region of the voltage waveform (measurement range B), the amplifier 14 having an amplification factor of 50 is selected, and in the c region of the voltage waveform (measurement range C), the amplifier 14 having an amplification factor of 100 is selected. In the d region (measurement range D), the amplifier 14 having an amplification factor of 1000 is selected.

  By adding up the output voltages of these four amplifiers 14, the voltage waveform output from the Hall element 13 of the magnetic field sensor 15 approximates the current waveform of lightning surge. Thus, the amount of coulomb can be calculated with high accuracy by calculating the area of the voltage waveform (shaded portion in the figure) that approximates the current waveform of the lightning surge.

  In addition, although the case where all four amplifiers 14 were selected was illustrated above, one amplifier 14, two amplifiers 14 or three of the four amplifiers 14 depending on the current waveform of the lightning surge. The amplifier 14 may be selected.

  Moreover, it is preferable to arrange | position magnetic bodies, such as a ferrite core, for example between the magnetic field which generate | occur | produces with the surge current which flows into the windmill tower 11 by a lightning strike, and the Hall element 13. By adopting such a structure, the lines of magnetic force applied to the Hall element 13 can be reduced.

  As a result, the voltage waveform output from the Hall element 13 can be approximated to the current waveform of a lightning surge, even for an excessive lightning surge that cannot be measured even with an amplifier having an amplification factor of 1, for example.

  As described above, in the coulomb amount measuring device 12 of this embodiment, the voltage waveform output from the hall element 13 of the magnetic field sensor 15 approximates the current waveform of the lightning surge, so that the coulomb amount can be calculated with high accuracy. Can do.

  When a current sensor such as a CT (current transformer) or Rogowski coil is used as in the prior art, as shown in FIG. 4A, if the duration of the surge current is long, the coil of the current sensor itself By magnetic saturation, the amount of coulomb (shaded portion in the figure) can be obtained only until time T when the current sensor is magnetically saturated. As a result, it becomes difficult to accurately measure the coulomb amount.

  On the other hand, by using the Hall element 13 as the magnetic field sensor 15 as in this embodiment, as shown in FIG. 4B, the Hall element 13 itself even if the duration of the surge current is long. Is not magnetically saturated, the voltage waveform output from the Hall element 13 approximates the current waveform of the lightning surge, so that it becomes easy to accurately measure the amount of coulomb (the hatched portion in the figure).

  Moreover, in the coulomb amount measuring device of this embodiment, a structure in which the hall element 13 is bent with a metal capable of blocking electromagnetic waves, for example, a copper shield, is preferable. By adopting such a shield structure, it is possible to reduce a strong electromagnetic wave generated during a lightning strike.

  Thereby, the noise component of the electromagnetic wave at the time of a lightning strike can be removed. As a result, the voltage waveform output from the Hall element 13 shielded by the shield body can be approximated to the current waveform of lightning surge without being adversely affected by electromagnetic waves, and the amount of coulomb can be accurately measured. .

  In the embodiment shown in FIG. 1, the magnetic field sensor 15 in which a plurality of (four) Hall elements 13 are arranged at the same distance from the wind turbine tower 11 has been described, but the present invention is not limited to this, The magnetic field sensor 15 having the structure shown in FIG. In FIG. 5, the same parts as those in FIG.

  The coulomb amount measuring device 12 of the embodiment shown in FIG. 5 includes a magnetic field sensor 15 in which a plurality (four) of hall elements 13 are arranged at different distances from the wind turbine tower 11. In this case, the amplification factor of the amplifier 14 connected to the output of each Hall element 13 is set to be the same.

  Here, in the coulomb amount measuring device 12 of the embodiment shown in FIG. 1, a plurality of amplifiers connected to the output of each hall element 13 by arranging a plurality of hall elements 13 at the same distance from the wind turbine tower 11. 14 includes a magnetic field sensor 15 having different gains.

  In the coulomb amount measuring device 12, the level of the detection signal output from the magnetic field sensor 15 is varied by varying the amplification factor of the amplifier 14.

  As a result, the controller 16 selects the optimum output of the amplifier 14 in accordance with the magnitude of the magnetic field generated by the lightning strike, and adds the outputs of the amplifiers 14 to obtain a voltage waveform that approximates the current waveform of the lightning surge. Thus, the amount of coulomb is calculated with high accuracy.

  On the other hand, in the coulomb amount measuring device 12 of the embodiment shown in FIG. 5, a plurality of hall elements 13 are arranged at different distances from the wind turbine tower 11 and a plurality of hall elements 13 connected to the outputs of the hall elements 13 are arranged. The magnetic field sensor 15 having the same amplification factor of the amplifier 14 is provided.

  In this coulomb amount measuring device 12, the plurality of hall elements 13 are arranged at different distances from the wind turbine tower 11, so that the level of the detection signal output from the magnetic field sensor 15 is varied.

  As a result, the controller 16 selects the optimum output of the amplifier 14 in accordance with the magnitude of the magnetic field generated by the lightning strike, and adds the outputs of the amplifiers 14 to obtain a voltage waveform that approximates the current waveform of the lightning surge. Thus, the amount of coulomb is calculated with high accuracy.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

11 Object (windmill tower)
12 Coulomb measuring device 13 Hall element 14 Amplifier 15 Magnetic field sensor 16 Controller

Claims (4)

A Hall element that is disposed in proximity to the object and detects a magnetic field generated by a lightning strike on the object; and an amplifier that is connected to the output of the Hall element and amplifies a detection signal output from the Hall element Comprising a magnetic field sensor comprising: a controller connected to the output of the magnetic field sensor, and calculating a coulomb amount during a lightning strike on the object based on a voltage waveform of a detection signal output from the amplifier ; The controller is configured to input the size of the object and the separation distance between the object and the Hall element .   The magnetic field sensor has a structure in which a plurality of Hall elements are arranged at the same distance from an object, amplifiers are connected to outputs of the Hall elements, and amplification factors of the amplifiers are different from each other. 1. The coulomb amount measuring device according to 1.   2. The coulomb amount according to claim 1, wherein the magnetic field sensor has a structure in which a single Hall element is arranged with respect to an object and a plurality of amplifiers having different amplification factors are connected to the output of the Hall element. Measuring device.   The magnetic field sensor has a structure in which a plurality of Hall elements are arranged at different distances from an object, amplifiers are connected to outputs of the Hall elements, and amplification factors of the amplifiers are the same. 1. The coulomb amount measuring device according to 1.

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