JP2728581B2 - Lightning impulse current meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention counts the degree of lightning strike on a protection facility in order to provide maintenance and management for lightning damage to weather observation facilities, road management facilities, production facilities or various facilities for academic research. It is related to the frequency meter to perform.

[0002]

2. Description of the Related Art Conventionally, a lightning impulse current is measured mainly by using an expensive measuring instrument for academic research, for example, a high-frequency current transformer, a high-speed storage oscillograph, etc., and performing a large-scale measurement to obtain a peak value of the lightning current. , Duration, waveforms, etc., which are used by various universities and research institutes, and are effective.

[0003] However, these are expensive and large-scale, and are not common. For maintenance of general production equipment using lightning arresters and lightning rods as a countermeasure against lightning damage, it is very effective to simply estimate how many times the lightning current will strike.

[0004] For this purpose, many measuring means have been proposed and are known.

[0005] 1. Method of measuring using magnetic steel slab
A lightning impulse current is passed through a coil of one or two turns,
Place a coercive iron piece inside this coil,
Magnetize the iron piece by lightning current and measure the degree of magnetization with a magnetometer.It has a large error, but you can get an overview of the magnitude of lightning current, and in that sense it is convenient, but the following disadvantages There is.

(A) The number of lightning current passages is unknown.

(B) It is difficult to make a coil without a specialized machine tool, and since there are few sales channels, it is custom-made and expensive compared to its function.

(C) It is necessary to periodically go to the mounting point and replace the iron piece.

(D) Both a magnetometer and a degausser are required.

[0010] 2. A method of measuring using a voltage divider.

[0011] A device in which "extremely low impedance" is inserted into a ground line, a voltage drop due to a lightning impulse current is divided at this portion, and this voltage is led to a detection circuit to operate a counter.

At present, almost all of the "lightning arrester discharge frequency measuring devices" are of this type. Although each is devised, there are the following problems.

(A) The passing lightning impulse current has a peak value ranging from about 100 A to several thousand A or more (according to a research report by the Central Research Institute of Electric Power Industry), and the detection performance can correspond to this. Absent.

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

(C) For this reason, there are many methods in which a voltage is once applied to the capacitor from the voltage divider. However, the withstand voltage of the capacitor needs to be appropriate for the estimated maximum value of the expected passing current from the viewpoint of maintenance, and protective measures are required.

(D) It is difficult to select the capacity of the capacitor, and depending on the passage time of the lightning current, the energy for operating the counter circuit may be insufficient, resulting in a miscount. (Since the impedance of the voltage divider and the capacitor are in parallel, the magnitude of the detection signal differs depending on the wavelength of the lightning impulse.)

In the above-mentioned conventional measuring means: The magnitude of the peak value of the lightning impulse current is extremely large, and a special measuring circuit and a protection circuit are required to cope with this.

2. Wavelength of lightning impulse current (duration)
However, it is necessary to devise a method for taking in the signal, and the reliability is not sufficient.

[0019]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks, to sufficiently cope with the difference between the peak values of the lightning impulse current, and to reliably use short pulses without using a voltage dividing circuit. An object of the present invention is to provide a power meter that can be grasped.

[0020]

The means of the present invention are as follows.

1. One end of a pair of leads made of ferromagnetic alloy is parallel to each other with a small space between them, and each is a movable piece, and both movable pieces are sealed in a glass tube and fixed, and a magnetically responsive switch is fixed by a lightning impulse It is installed at right angles to the down line of the lightning rod through which the current passes or the ground wire of the lightning arrester, and the magnetically responsive switch is opened and closed by using the magnetic attraction force caused by the instantaneous magnetic field generated by the lightning impulse current, so that the lightning impulse current is supplied A lightning impulse current meter that accumulates the number of times.

2. A C-shaped silicon steel sheet laminated iron core is provided around the lead wire of the lightning rod through which the lightning impulse current passes or the grounding lead wire of the lightning arrester, and one end of a set of leads made of a ferromagnetic alloy is slightly spaced. Each movable piece is opposed to and parallel to each other to form a movable piece, and a magnetically responsive switch in which both movable pieces are sealed and fixed in a glass tube is installed in parallel with the opening of the iron core, and the number of operations is integrated. And a power meter for lightning impulse current.

3. An excitation solenoid is connected in series between the down conductor of the lightning rod through which the lightning impulse current passes or the grounding down wire of the lightning arrester, and one end of a pair of ferromagnetic alloy leads is connected in parallel with a slight gap. A lightning impulse, characterized in that a magnetically responsive switch in which both movable pieces are sealed in a glass tube and fixed is mounted inside the solenoid, and the number of times of operation of the magnetically responsive switch is integrated. Electric current meter.

[0024]

The operation according to the present invention will be described with reference to FIG. 1. A solenoid 4 wound several times is sandwiched between a ground pull-down conductor 3 of a lightning arrester (or a lightning rod) 2 and a magnetic center is provided at the center of the center of the solenoid 4. And a magnetically responsive switch 8 containing a movable piece 7 having a movable distance as small as possible.

When a current flows through the solenoid 4, magnetic lines of magnetic force penetrate the inside of the solenoid, causing N and S poles to be induced in the lead pieces, and the movable piece 7 is closed by their magnetic attraction. In this case, although the energization time is very short, the movable piece 7 is closed by inertia even if the current disappears because it has a much larger ampere turn than the minimum operation ampere turn of the movable piece 7.

Next, the conduction time of the gate current for igniting the thyristor 12 shown in FIG. 2 may be very short, so if the contact is connected to the gate circuit of the thyristor 12, the thyristor 12 Arcing is performed to operate the counting circuit.

[0027]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an embodiment of a lightning impulse current meter according to the present invention.

FIG. 1 shows a detecting unit 1 in which a ground pull-down conductor 3 of an arrester 2 is cut, and a solenoid 4 wound once or several times is attached during the cutting. The solenoids 4 are fitted with stop members 5 and 5 up and down so as to fit in the center of the interior, and the socket body 6 is inserted and fitted. In addition, a magnetically responsive switch 8 containing movable pieces 7, 7 which are opposed to each other in parallel with a small interval so as to fit in the center is inserted into the socket body 6, and provided at the upper and lower ends of the magnetically responsive switch 8. It is fixed with a switch stopper and lead wire reinforcing piece 9. Connect the switch lead to signal line 1.
0 (two-core cable of a and b) is connected to the input terminal 11 (FIG. 2) of the counting unit.

FIG. 2 shows a counting unit. Terminals a and b of the two-core cable signal line 10 from FIG.
Connect to 1. The pulse entering the terminal 11 enters the gate through the resistor 13 connected to the gate of the thyristor 12. The gate signal is supplied from the power supply battery 14. When a current flows through the gate, the thyristor 12 fires, exciting the coil of the relay 15 and continuing the current. The contact a of the relay operates, the timer 16 starts, and the electromagnetic counter 17
Count.

The timer 16 has a preset time (50 to 100 m.
As soon as s) is passed, the b-contact is activated and the current of the thyristor main circuit is cut off. The relay and timer also return to the standby state. If necessary, the counter reset button 18 is pressed to return. When the battery 14 is left for a long time, it can be charged by the solar battery 19 and the diode 20 as appropriate.

Next, FIG. 3 shows another embodiment of the detecting section 1 utilizing a magnetic circuit generated by a high voltage. A C-shaped silicon steel sheet laminated iron core 29 is installed on the outer periphery of the down conductor 3 of the lightning rod. The iron core 29 strengthens the magnetic lines of force, and furthermore, the socket body 6 is positioned between the two poles of the iron core 29 at right angles to the pull-down conductor 3, and furthermore, it is movable within the socket body 6 so as to be centered. The magnetically responsive switch 8 containing the pieces 7 and 7 is inserted, and the lead wires provided at both ends of the magnetically responsive switch 8 are fixed by switch stopper and lead wire reinforcing pieces 9.
This lead wire is connected to the input terminal 11 of the counting section by a two-core cable signal line 10.

[0032]

According to the present invention, the detecting unit does not directly use the lightning impulse current but indirectly and instantaneously uses the magnetism generated by the current. Considerations can be ignored. In addition, since a magnetically responsive switch enclosed in a socket body made of a glass tube having a diameter of about 3 mm is used, even when the magnetizing force becomes extremely large, the magnetic field lines applied to the contact circuit are in a state similar to saturation, and are strong against the movable piece. There is no force or deformation of the contacts. Also, no residual magnetism remains. These have a peak value of 1 with a lightning impulse current (wave tail length 20 to 100 μs).
The experiment was repeated from about 00 A to several thousand A, and it was confirmed.

As the thyristor circuit, only the contact is used for the gate circuit, a power supply of about 12 V DC is sufficient, and there are almost no other trouble occurrence conditions.
Its operation is reliable and great reliability is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a detection unit of a lightning impulse current conduction meter according to the present invention.

FIG. 2 is an explanatory diagram of a counting unit according to the present invention.

FIG. 3 is an explanatory diagram showing another embodiment of the detection unit of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Overview of detection part 2 Lightning arrester 3 Pull-down grounding conductor 4 Solenoid by conductor 5 Stopping member 6 Socket body (protective cylinder) 7 Movable piece 8 Magnetically responsive switch 9 Switch stop and lead wire reinforcing piece 10 2-core cable signal wire 11 Input terminal 12 Thyristor 13 Resistance 14 Battery for power supply 15 Relay 16 Timer 17 Electromagnetic counter 18 Reset button 19 Solar battery 20 Diode

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-36701 (JP, A) JP-A-56-19331 (JP, A) JP-A-57-145523 (JP, A) 155771 (JP, A) JP-A-63-201569 (JP, A) JP-A-60-40968 (JP, A) JP-A-56-97879 (JP, A) JP-A-55-68023 (JP, A) Japanese Utility Model Showa 56-106018 (JP, U) Japanese Utility Model Showa 57-75426 (JP, U) Japanese Utility Model 2-44220 (JP, Y2) Japanese Utility Model Showa 61-4032 (JP, Y2)

Claims (3)

(57) [Claims] 1. A magnetically responsive device in which one end of a set of leads made of a ferromagnetic alloy is made parallel to each other with a small space therebetween to form movable pieces, and both movable pieces are sealed and fixed in a glass tube. A switch is installed at right angles to the down line of the lightning rod through which the lightning impulse current passes or the grounding wire of the lightning arrester, and the magnetically responsive switch is opened and closed by using magnetic attraction by an instantaneous magnetic field generated by the lightning impulse current, A lightning impulse current meter that accumulates the number of times lightning impulse current is applied. 2. A C-shaped silicon steel sheet laminated iron core is provided on the outer periphery of a lead wire of a lightning rod through which a lightning impulse current passes or a ground lead wire of a lightning arrester, and one end of a set of leads made of a ferromagnetic alloy is slightly reduced. Movable pieces are made to face each other in parallel with an interval, and a magnetically responsive switch in which both movable pieces are sealed and fixed in a glass tube is installed in parallel with the opening of the iron core, and the number of times of operation is set. A lightning impulse current meter that integrates. 3. An exciting solenoid is connected in series between a down conductor of a lightning rod through which a lightning impulse current passes or a ground down line of a lightning arrester, and one end of a pair of leads made of a ferromagnetic alloy is connected at a small interval. Each movable piece is made to face each other in parallel with the existence of a magnetically responsive switch, and both movable pieces are sealed in a glass tube, and a fixed magnetically responsive switch is mounted inside the solenoid, and the number of times of operation of the magnetically responsive switch is integrated. And a power meter for lightning impulse current.