JPH075422Y2 - Detectors by intensity of lightning impulse current - Google Patents

Description

[Detailed description of the device]

[0001]

[Industrial field of application] The present invention provides a lightning impulse at the time of a lightning strike to a weather observation facility, a road management facility, a production facility, or a protection facility for maintenance and management against lightning damage to various facilities for academic research. The present invention relates to a detector that detects electric current according to strength.

[0002]

2. Description of the Related Art Conventionally, as a method for measuring a lightning impulse current, a large-scale measurement has been performed by using an expensive measuring instrument mainly for academic research, for example, a high frequency current transformer, a high speed storage oscillograph, etc. There is a method of observing peak value, duration, waveform, etc., and it is used in universities, research institutions, etc. and is effective.

Further, as a general measurement, there are a method using a magnetic steel piece and a method using a voltage divider. The former measurement using a magnetic steel piece was conducted with a lightning impulse current of 1-2.
A coil of winding is energized, an iron piece with a strong coercive force is placed inside this coil, the iron piece is magnetized by a lightning current, and the degree of this magnetization is measured with a magnetometer. You can grab it. However, a degausser is needed as well as a degausser.

Furthermore, in the latter method of measuring using a voltage divider, an "extremely low impedance" is inserted in the ground wire portion,
There is a method of dividing the voltage drop due to the lightning impulse current in this portion and guiding this voltage to the detection circuit to operate the counter, but there are the following problems.

A) The passing lightning impulse current has a range from about 100 A to 10 KA or more in peak value, and the detection performance cannot cope with this.

B) The time of the passing lightning impulse current is approximately 100 μs or less, and sometimes 20 to 30 μs when the time is short.

C) For this reason, the voltage is often once received by the capacitor from the voltage divider.

1. The withstand voltage of the capacitor must match the estimated maximum value of the expected passing current, and protection measures will also be required.

2. It is difficult to select the capacitor capacity.

[0010]

In the above-mentioned conventional measuring method, the difference in the peak value of the lightning impulse current is remarkably large, and in order to cope with this, a special measuring circuit and a protective circuit are required, and it is sufficient. Unreliable. Also, since the wavelength of the lightning impulse current is short, it was necessary to take some measures to incorporate the signal.

Therefore, the present invention provides a method capable of coping with a large difference in the peak value of the lightning impulse current and capable of surely grasping a very short pulse without using a voltage dividing circuit.

[0012]

As means for solving the above-mentioned problems, even if there is a large difference in the peak value of the lightning impulse current, in order to cope with this, the number of turns of the series circuit of a part of the ground line and The exciting solenoids made of materials whose resistances are changed are arranged in parallel, and the magnetically responsive switch is located inside the exciting solenoids so that even very short pulses can be reliably grasped.

[0013]

In the present invention, branch circuit terminals 4 and 5 are provided in a part of the grounding pull-down conductor 3 of the lightning arrester 2, and the magnetic circuit switch 14 is provided in the branch circuit in the cylinder 9 of the exciting solenoid 10 in which the number of turns and the resistance are changed. And the exciting solenoid 10 is connected in parallel to both terminals 4 and 5 of the ground pulling-down conductor 3 by terminals 6 and 7. The lightning impulse current passing through the lightning arrester 2 has a peak value of about 100 A to a width of 10 KA or more, but if the current is small, the solenoid is directly energized, or the number of turns and resistance of the branch solenoid are reduced, and a large amount of current flows. On the contrary, when it is desired to detect a large current, the number of windings and resistance of the solenoid are increased and the current flowing through the solenoid is reduced.

When a current flows through the electromagnetic solenoid 10, a magnetic line of force is generated inside, whereby the alloy contact piece 13 of the response switch 14 is closed. At this time, although the energization time is minute, the lightning impulse current has a much larger ampere-turn than the lowest operating ampere-turn of the alloy contact piece 13, so that even if the current disappears, the alloy contact piece 13 is closed due to inertia and the lead wire. Will get the circuit and input.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a detector according to the intensity of a lightning impulse current according to the present invention, which will be described below with reference to the drawings.

Reference numeral 1 denotes a box body, and this box body 1 is located at the cut portion of the lightning arrester 2 where the grounding down conductor 3 is cut.

Further, inside the box 1, the end terminals 4 and 5 of the pull-down conducting wires 3 and 3 are located, and the terminals 4 and 5 are connected by the same conducting wire 8 as the ground pull-down line. I am doing it.

The terminals 4 and 5 of the conductors 3 and 3 are provided with the ends of the coil conductor 10a of the exciting solenoid 10 whose resistance and the number of turns wound around the outer periphery of the cylinder 9 of the insulator are changed by the terminals 6 and 7, respectively. The exciting solenoid 10 is connected in parallel to divide the current, and the cylinder 9 of the exciting solenoid 10 is provided with stopper members 11 and 11 on the upper and lower sides, and is mounted on a receiving piece 12 in the casing 1.

In the cylinder 9, a movable alloy contact piece 13 is provided.
The magnetically responsive switch 14 accommodating the above is inserted, and the magnetically responsive switch 14 is fixed in the cylinder 9 by the switch stopper / lead wire reinforcing pieces 15 provided at the upper and lower ends.

The switch lead wires a and b are connected to a connector 16 attached to the outside of the box body 1, and the lead wires a and b of the connector 16 are guided to the outside through a socket 17 to count. It is designed to be connected to the input side such as.

[0021]

According to the present invention, the lightning impulse current is detected by indirectly and instantaneously utilizing the magnetic force generated by the current that is shunted to the exciting solenoid connected in parallel with the grounding down wire. This exciting solenoid can detect the current by adapting to the magnitude of the current by changing the number of turns of the coil winding and the resistance, and the operation is reliable and reliable.

[Brief description of drawings]

FIG. 1 is a front view of a lightning impulse current detector of the present invention.

FIG. 2 is a layout of detectors.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shield 2 Lightning arrester 3 Grounding down conductor 4, 5, 6, 7 Terminal 8 Part of earthing down conductor 9 Cylindrical 10 Excitation solenoid 10a Coil conductor 11 Stop member 12 Receiving piece 13 Alloy contact piece 14 Magnetic response switch 15 Switch Fixing and lead wire reinforcement piece 16 Connector 17 Socket a, b Lead wire

Claims (1)

[Scope of utility model registration request] 1. A series circuit including an element for directly passing a current through a grounding pull-down wire of a lightning arrester through which a lightning impulse current passes, and an exciting solenoid having a number of turns and a resistance changed between the terminals of the series circuit are connected in parallel. A lightning impulse current intensity detector characterized in that a magnetic responsive switch is mounted inside the exciting solenoids connected in parallel as described above.