JP2990663B2 - Large-diameter Rogowski coil device and large current detection device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-diameter Rogowski coil device suitable for detecting a large current, and a large current which can be used to observe an event such as a lightning current in which a large current flows instantaneously. It relates to a detection device.

[0002]

2. Description of the Related Art A coaxial shunt is used as a sensor for observing a large current having a large value of several tens of kA, such as a lightning current, and a large value of 100 kA or more, such as a lightning current. CT, light C
T, Hall element, Rogowski coil and the like. However, these conventional sensors include towers, which are ground structures,
Since there is nothing to collectively measure the entire large area such as a radio relay station, building, etc., it is individually observed by multiple observation devices consisting of sensors and detection devices, and the waveforms of all observation devices are added. And seek the main current flowing by the lightning strike.

For example, as shown in FIG. 1, when a radar dome 4 and a lightning rod 5 are installed on a rooftop of a building 1 via a steel tower 2 and a scaffold 3, lightning strikes the lightning rod 5 and the surface of the radar dome 4 (Actually, the radar dome 4 is formed by connecting the FRP resin plates with connecting metal fittings into a bow shape, combining a plurality of these and forming a spherical shape, and the current flows through the connecting metal fittings). When observing,
In the conventional observation mode, four observation devices 6 each consisting of a coaxial shunt and the like are arranged on the four legs of the tower 2 in total, and one inspection ladder and one waveguide are installed. I am observing. For this reason, the general current situation is that observation costs such as equipment costs are too high and only small-scale observations can be performed.

It is said that it is desirable to attach a Rogowski coil constituting an observation device 6 to a lightning arrester 5 to observe a lightning current due to a lightning strike on the radar dome 4 as shown in FIG. However, if the Rogowski coil is to be mounted so as to have sufficient safety against strong winds, etc., the strength of the radar dome 4 must be considerably increased. Therefore, the strength of the radar dome 4 was not so large, and it was difficult to mount it. In addition, even if the strength of the radar dome 4 can be attached, the radar always emits radio waves and observes it, so there is a concern about the problem of observation that the operator is mistaken for raindrops and the effect of strong radio waves on the human body. Because of this problem, it was necessary to stop the radar every time the observation equipment was installed, and there was practically no possibility.

On the other hand, in order to measure the entire structure occupying a large area, it is considered that a large-diameter Rogowski coil may be manufactured. However, in a building as shown in FIG. 1, considering a Rogowski coil 7 that can be wound around the lower end of the leg of the tower 2, the wire length becomes several hundred meters,
There is a time difference of several microseconds in the coil output voltage generated between the winding start side and the winding end side of the coil. For example, as shown in FIG. 2, when a Rogowski coil 7 having a donut shape with a diameter of 10 m and a coil diameter of 30 mm is manufactured,
The total length of the coil is 31.4m and the coil winding pitch is 3mm
Then, the number of turns (number of turns) of the coil is 10466 turns (31.4 m ÷ 3 mm), and the wire length of one turn of the coil is 94.2 mm (30 mm × 3.14), so that the total wire length is about 980 m ( 10466 turns x 94.2 mm). It is assumed that a current application line 8 is arranged inside such a Rogowski coil 7 and a high-frequency large current is applied to this.
Then, a voltage is simultaneously generated at the winding start side and winding end side of the Rogowski coil 7. However, the time required for the voltage on the winding start side to reach the coaxial cable 9 connected to the winding start side and the voltage on the winding end side are changed by the coaxial cable 9.
Compared with the time required to reach the coaxial cable 9, the reaching distance at the light speed of 1 μs is 300 m, so that the voltage at the winding end side reaches the coaxial cable 9 in about 3.27 μs (980 m ÷).
300m).

However, since the lightning current has a high frequency and the rise time is very fast, as shown in FIG. 3, on the order of 1 μs, it is good for a large-diameter Rogowski coil which requires 3 μs or more before the rise as described above. Frequency characteristics cannot be obtained. That is, since the time difference between the voltage generated on the winding start side and the winding end side of the coil is 3 μs or more, the lightning current that can be measured by such a Rogowski coil is limited to a waveform with a rise of 10 μs or more. In addition, there is also a problem that the diameter is too large to be inconvenient to handle. Therefore, an object of the present invention is to provide a large-diameter Rogowski coil device as a sensor that can collectively measure the entirety of a large-area structure or the like, and a large-current detection device using the same.

[0007]

In order to achieve the above object, a large-diameter Rogowski coil device according to the present invention is capable of forming donut-shaped Rogowski coils having a desired diameter and independently connecting each other. A plurality of divided coil bodies, an integrating amplifier connected to each of the divided coil bodies and integrating and outputting an output of the corresponding divided coil body, and an adding amplifier for adding the output of each of the integrating amplifiers. It is characterized by.

In order to achieve the above object, the large current detecting device according to the present invention is provided with means for performing, at least for the large-diameter Rogowski coil device, at least arithmetic processing of the addition amplifier output of the large-diameter Rogowski coil device. It is characterized by being connected.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the following, description will be made by assigning common reference numerals to parts common to the related art. FIG. 4 shows an example in which a large-diameter Rogowski coil device and a large-current detection device according to one embodiment of the present invention are used to configure a device for observing a lightning current that strikes the rainfall radar shown in FIG. 1. The apparatus according to the present embodiment includes a large-diameter Rogowski coil 1 around a base of a radar dome 4 on a steel tower 2, that is, around a scaffold 3 in the illustrated example.
A lightning current that strikes the lightning rod 5 with 0 is observed.

FIG. 5 is a block diagram showing the configuration of the large current detecting device according to this embodiment. As shown, the large-diameter Rogowski coil 10 of the present apparatus has a desired diameter, for example, 1 mm.
0 m or 20 m,
Four independently formed quarter quarter circles
Rogowski coils 11a, 11b, 11c and 11d are used in a circular arrangement. 1/4 Rogowski coil for each 1
1a to 11d are integrating amplifiers 12a and 12b, respectively.
12c, 12d, and each integrating amplifier 12a-12d
Is input to the addition amplifier 13, the output is A / D converted by the A / D converter 14, and further input to the microcomputer 15 for arithmetic processing. Although not shown, the processing result, that is, the detected lightning The current waveform is displayed on a well-known display device.

The large-diameter Rogowski coil 10 is formed by winding an electric wire around an outer periphery of a core material (not shown) made of an insulating material such as a vinyl hose or a plastic tube, as shown in FIG. It is connected to integrating amplifiers 12a to 12d via a coaxial cable 16. The integrating amplifiers 12a to 12d do not saturate but have a voltage of 1 to the coil output voltage because the Rogowski coil core is an air core (insulator).
Since a differential wave of the secondary current waveform is generated, the output voltage is integrated to obtain a waveform similar to the primary current.

The length of the coaxial cable 16 is 1 /
The four Rogowski coils 11a to 11d may be manufactured to have the same length so that the voltages can be transmitted to the integrating amplifiers 12a to 12d without a time difference. In addition, the integration amplifiers 12a-1
2d, an addition amplifier 13, an A / D converter 14, an electronic circuit such as a microcomputer 15, and an electronic device include a recording device 1.
As 7, the large-diameter Rogowski coil 10 may be installed as close as possible to the installation place by the coaxial cable 16.

The diameter and the number of divisions of the large-diameter Rogowski coil 10 are not limited to those of the embodiment described and illustrated above. That is, in the present embodiment, a divided Rogowski coil having a diameter of 10 m or 20 m is configured as a 1/4 Rogowski coil, but the diameter and the number of divisions can be freely set. However, if the length of one divided Rogowski coil is too long, the same problem as that of the integrated Rogowski coil occurs in the frequency characteristics.If the number of divisions is too large, the number of integrating amplifiers to be connected increases and the current consumption increases. In view of these points, the number of divisions is desirably as small as the frequency characteristics of the large-diameter Rogowski coil 10 allow. However, it is desirable that the winding pitch of the divided Rogowski coil and the cross-sectional area of each turn be constant as much as possible because if there is a variation in these windings, electromagnetic induction from outside is induced.

For example, as shown in FIG.
Assuming that a lightning current (A in the figure) flows for 2 seconds, as described above, if the rising characteristic of the output voltage of a non-divided Rogowski coil having a diameter of 10 m is 6 μs and the output is 1 V (B in the figure) ), The above-mentioned quartered 1/4 Rogowski coil 11
Since the coil wire length is 1/4, the rise time of a to 11d is about 1/4 of the rise time of the voltage output to the coil output end, and the number of coil turns is 1/4. , The generated voltage is lowered and the output voltage is reduced to about 0.25 V, which is one fourth. If it is divided into six, the rise of one divided Rogowski coil can be calculated in 1 μsec, which is very convenient.

It is necessary to calibrate the output voltage of the divided Rogowski coil so as to show the same output value for the same lightning current. FIG. 8 is a circuit diagram showing the configuration of the device for calibration. For calibration with this apparatus, only one 1/4 Rogowski coil 11a was made circular and the inside thereof was set so that the current application line 8 passed therethrough. Is applied so that the output of the integrating amplifier 12a becomes 1.0 V.
Adjust a. Next, the 1/4 Rogowski coil 11a is removed, and the next 1/4 Rogowski coil 11b is similarly attached and adjusted.
11d is adjusted similarly.

The four 1/4 Rogowski coils 11a to 11d, which have been calibrated as described above, are all set in a circular shape and set on the current application line 8, and the large current generator 18
When 00 kA is applied, the outputs of the integrating amplifiers 12a to 12d are all 1.0V, and the output of the adding amplifier 13 is 1.0V.
It becomes 400 kA at 4.0 V with × 4 times. When one circular coil is formed by the four 1/4 Rogowski coils 11a to 11d and set to the current application line 8 and 100 kA is applied, the integration amplifiers 12a to 12d
Are 0.25 V, and the output of the summing amplifier 13 is 1.0 V, which is 0.25 V × 4 times. That is, the divided 1/4 Rogowski coils 11a to 11d have the same performance even if the lengths of the four Rogowski coils are slightly different if the winding pitch and the cross-sectional area are constant. There will be no problem.

[0017]

As described above, the large-diameter Rogowski coil device according to the present invention has a large area by connecting a plurality of divided Rogowski coils to an integrating amplifier and adding their outputs. Calibration test can be easily configured even if it has a diameter that can collectively measure the entire structure, etc., and can improve the frequency characteristics compared to using a single non-divided Rogowski coil of the same diameter. Also, there is an effect that handling is convenient because the weight, size and the like per unit are reduced because the unit is divided.

As described above, the large current detecting device according to the present invention is a large-diameter Rogowski coil device in which a plurality of divided Rogowski coils are connected to integrating amplifiers, respectively, and the outputs thereof are added. And the output is calculated, so that the frequency characteristics of large current waveforms such as lightning current flowing in large-area structures can be collectively and faithfully observed, and the observation cost can be greatly improved. effective.

[Brief description of the drawings]

FIG. 1 is a diagram showing an arrangement of a radar dome installed on the roof of a building and a conventional observation device for lightning current flowing through a lightning rod thereof.

FIG. 2 is a conceptual diagram showing a large-diameter Rogowski coil composed of one coil.

FIG. 3 is a diagram illustrating a rising characteristic of a lightning current.

FIG. 4 is a view corresponding to FIG. 1 showing an apparatus according to an embodiment of the present invention.

FIG. 5 is a circuit diagram showing an embodiment of a large-diameter Rogowski coil device according to the present invention and a large-current detection device using the same.

FIG. 6 is a view showing a 1/4 Rogowski coil constituting the large-diameter Rogowski coil device of FIG. 5;

FIG. 7 is a diagram illustrating a difference in output voltage between a large-diameter Rogowski coil and a 1/4 Rogowski coil formed of one coil for the same applied current.

FIG. 8 is a diagram showing a calibration device for a 1/4 Rogowski coil.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Building 2 Steel tower 3 Scaffold 4 Radar dome 5 Lightning rod 8 Current application line 10 Large-diameter Rogowski coil 11a, 11b, 11c, 11d 1/4 Rogowski coil 12a, 12b, 12c, 12d Integral amplifier 13 Addition amplifier 14 A / D Converter 15 Microcomputer 16 Coaxial cable 17 Recording device 18 Large current generator

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01R 15/18 H01F 38/20-38/40

Claims (2)

(57) [Claims] 1. A plurality of split coil bodies which can form a donut-shaped Rogowski coil having a desired diameter and are independently connected to each other, and each of the split coil bodies is connected to a corresponding one of the split coil bodies. A large-diameter Rogowski coil device comprising: an integrating amplifier for integrating and outputting an output; and an adding amplifier for adding the output of each of the integrating amplifiers. 2. A large current detecting device comprising: a large-diameter Rogowski coil device according to claim 1; and at least means for calculating the addition amplifier output of said large-diameter Rogowski coil device. .