JPH01316667A - Live line current measuring device - Google Patents

Abstract

PURPOSE:To execute a measurement of an activated wire current with a simple operation by only pressing a clamp core of a conductor clamp upon a conductor by providing a conductor guide means with the clamp core, and automatically holding a current value. CONSTITUTION:When a clamp core 1 is pressed against a compression spring 7 in an arrow direction while keeping guide members 9a and 9b pressed on the side of a conductor 10a, the members 9a and 9b are revolved around a shaft 3 as a fulcrum together with core members 1a, 1b and the core 1 is opened. When the core 1 is further pressed, the conductor 10a is fetched in an interior of the core 1. At this time, the members 1a, 1b are reverted by an energizing force of the spring 7, the core 1 is closed again then a conductor 10b is clamped. Accompanying with the open-close of this core 1, if a connection rod 4 moves apart from a switch 8, the switch 8 is turned ON, then, if the core 1 is closed, the switch 8 is pressed again and turned OFF. Moreover, if the core 1 is pulled from a clamp state in the direction opposite to the arrow, the members 9a, 9b are opened then the clamp of the conductor 10b is released.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention is applicable to high voltage applications such as those on top of power transmission towers.
The present invention relates to a live line current measuring device that measures the current flowing through a conductor such as a power transmission line.

[Conventional technology]

Generally, something called a clamp tester is used to easily measure the current in a conductor. There is also a clamp tester that is attached to the tip of an insulating rod in order to measure the current of a conductor at a high place, but the clamp tester that opens and closes the clamp part that clamps the conductor is operated remotely from the hand. has been completed.

[Problem to be solved by the invention]

Conventional clamp testers cannot measure current under high voltage, and the operation of the opening/closing mechanism of the clamp section is complicated. Conventionally, the current in a power transmission line could be checked at a substation, but in the case of multiple conductors, only the total current could be checked. There was no measuring device that could safely and easily measure flowing current in real time and at any location, such as on a power transmission tower.

The object of the present invention is to provide a live-line current measuring device that can safely measure the current of a conductor under high voltage at high places or any other place with simple operations. be.

[Means to solve the problem]

The live line current measuring device according to the present invention is provided with a conductor guide means that opens and closes the annular clamp core to clamp the conductor by simply pressing the clamp core against the conductor, and a switch that is linked to the opening and closing operation of the clamp core. established,
According to the operation of this switch, the current of the conductor clamped to the clamp core is measured at a predetermined time, and the measured current value is held.

[Effect]

The live line current measuring device according to the present invention clamps the conductor to the clamp core with a simple operation by the conductor guide means, and automatically measures the current at a predetermined time.
The current value is held.

〔Example〕

An embodiment according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an opening/closing structure a of a clamp core 1, and this clamp core 1 is formed into an annular shape by two core members 1a and lb. The core members 1a and lb have one end connected to a common shaft 3.
is rotatably connected to one end of the connecting rod 4.

A compression spring 7 is interposed between the flange portion 5 provided on the connecting rod 4 and the fixing member 6. The connecting rod 4 passes through the fixed member 6, and its end surface abuts the switch 8.

At the tips of the core members 1a, lb, conductor guide means 9a,
9b is provided. These conductor guide means 9a, 9b
In this embodiment, the guide member 9a has a semicircular shape.
, 9b are used. Further, 10a shown by a virtual line shows the conductor to be measured before being clamped, and 10b shows the conductor clamped to the clamp core 1.The clamp core 1 is provided with a detection coil to be described later. However, illustration is omitted here.

In the above configuration, as shown in the figure, when the clamp core 1 is pressed against the compression spring 7 in the direction of the arrow with the guide members 9a and 9b pressed against the side surface of the conductor 10a, the dotted line in the figure As shown, the guide members 9a, 9b are rotated together with the core members 1a, lb about the shaft 3, and the clamp core 1 is opened.

If the clamp core 1 is still pressed, the conductor 10a will be taken into the interior of the clamp core 1. At this time, the core member 1a,
lb is returned to its original state by the bias of the compression spring 7, the clamp core 1 is closed again, and the conductor 10b is clamped. As the clamp core 1 opens and closes, the connecting rod 4 first moves in the direction of arrow a and leaves the switch 8, which turns on the switch 8. Next, when the clamp core 1 closes, the switch 8
is pressed again to turn it off. Further, if the clamp core 1 is pulled in the direction opposite to the arrow a from the clamped state, the guide members 9a and 9b are opened and the clamp on the conductor 10b is released.

FIGS. 2 and 3 show the appearance of a live-line current measuring instrument equipped with the above-mentioned clamp core 1 and its opening/closing mechanism.

In FIGS. 2 and 3, the clamp core 1, its opening/closing mechanism, a current measurement and display circuit, etc., which will be described later, are provided in a case 11 shielded with an aluminum plate or the like. This case 11 is provided with a display section 12 having a display lid 12a, a battery 1113, etc., and is also appropriately provided with a power switch and the like (not shown). Further, this case 11 is attached to the tip of an insulating pipe 14 which is extendable and retractable. This insulating pipe 14 has adjustment screw portions 15° and 16
By adjusting the length, you can freely adjust the length. At the rear of this insulating pipe 14 is a grip section 1.
7 is provided. The total length from the rear end of the grip part 17 to the tips of the guide members 9a and 9b is the same as that of the insulating pipe 1.
By adjusting the length of 4, for example, 3.16 to 1.
It can be adjusted to about 7m.

According to the above configuration, after adjusting the insulating pipe 14 to an appropriate length, holding the grip part 17 by hand, pressing the insulating pipe 14 by pressing the guide parts 9a and 9b against the conductor to be measured. , the conductor can be flanged to the clamp core 1 as described above. Furthermore, the clamp can be easily released by pulling the insulating pipe 14 toward you.

Next, an embodiment of the electric circuit will be described with reference to FIG.

In FIG. 4, an internal shield 18 made of copper foil or the like is provided inside the case 11, and a current measurement and display circuit 19 and a control circuit F#1 are provided inside the internal shield 18.
20 are provided. Further, a detection coil 21 is wound around the clamp core l, and the current flowing through this detection coil 21 is measured by a current measurement and display circuit 19, and after the measured value is bolded by a current value hold circuit 22,
It is configured to be displayed on the display section 12.

In the control circuit 20, the switch 8 is turned on.

Inverter 23 applied via resistor R1 when turned off
The input level is changed. The capacitor C1 is provided to smooth noise caused by chattering of the switch 8 and the like.

The inverter 23 also has a Schmitt circuit configuration as a noise countermeasure. Monomulti 24 is
The time constant of resistor R2 and capacitor C2 is selected to be 6 seconds, for example, and depending on its Q and output, the transistor]
11 is controlled, and at the falling edge, monomulti 2
5 is triggered, and the oscillator 26 is operated. In the monomulti 25, the time constant due to the resistor R3 and the capacitor Cj is selected to be, for example, 15 seconds, and the output Q2 causes the transistor Tr2 to
The zero oscillator 26, which is configured to control
The output pulse is applied to the transistor Tr3.

The transistors T and I are connected in series with the transistor Tr2, and a relay 29 having a relay switch 29a is connected to the collector thereof.

The current measurement and display circuit 19 is controlled by this relay 29.
A speaker 30 is connected to the collector. The batch 31 supplies 10B to a predetermined circuit through the power switch 32.
tfi voltage.

Next, the operation of the above configuration will be explained with reference to FIG.

When the clamp core 1 is not clamping the conductor to be measured, the switch 8 is off, so the input of the inverter 23 is "H" (high level) and the output is "H" (high level).
At this time, the Q2 output of the monomulti 25 is rH, and the transistor Tr2 is turned on.

In this state, the above-described clamping operation of the clamp core 1 is performed, and when the clamp core 1 opens and closes to clamp the conductor 10b, the switch 8 is partially turned on and then turned off. By turning on this switch 8, the inverter 23
The input becomes rl, J, and the output rises to rHJ. At this rising edge, the monomulti 24 is triggered and its Q and output become r If J for 6 seconds. This turns on transistor T r+ and drives oscillator 26 .

When the transistors T and 1 are turned on, the relay 29 is energized and the relay switch 29a is turned on, thereby operating the current measurement and display circuit 19 and detecting the detection coil 21.
The current flowing through is measured for only 6 seconds. A current corresponding to the current flowing through the conductor 10b is induced in the detection coil 21 via the clamp core 1. On the other hand, the above 6
The oscillation output pulse of the oscillator 26 causes the transistor T,
3 is controlled and the speaker 30 is driven, whereby a signal tone of 3 KHz is emitted from the speaker 30.

When the current measurement is carried out for 6 seconds, the output Q falls to rL, the transistor Trl turns off, and the oscillator 2
6 stops oscillating, and the monomulti 25 is further triggered. Therefore, the relay switch 29a is turned off, and the speaker 30 stops emitting sound. As a result, the S current measurement and display circuit 19 stops measuring, and the measured current value is bolded in the current hold circuit 22 at the 0 display section 1.
2 displays this held current value as the current in the conductor 10b.

Also, after the mono multi 25 is triggered, the Q2 output is 15
This prevents the held current value from being released and prohibits re-measurement even if the switch 8 is accidentally turned on during these 15 seconds.

FIG. 6 is a block diagram conceptually showing the circuit of FIG. 5.

In FIG. 6, the switch 8 is operated in conjunction with the opening/closing operation of the clamp core 1, and thereby the control circuit 20 operates one current measurement and display circuit and the oscillation circuit 26.

As a result, current measurement is performed for 6 seconds, and an alarm sound is emitted from the speaker 30 during this time. When the measurement for 6 seconds is completed, the speaker 30 stops emitting sound, and the current measurement and display circuit 19 displays the measured current value.

Therefore, the displayed current value can be read after unclamping the conductor 10b.

〔Effect of the invention〕

According to the present invention, the guide members 9a, 9b are attached to the clamp core.
In addition to providing a conductor guide means such as , the current value is automatically held, so the conductor clamp can be easily operated by simply pressing the clamp core against the conductor without having to remotely control it at hand. It can be carried out. Furthermore, by attaching the clamp core to the tip of an insulated pipe or the like as in the embodiment, measurement work can be carried out safely and easily under high voltage at any location, such as on top of a power transmission tower.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the opening/closing mechanism of the clamp core in a live-line current measuring device according to an embodiment of the present invention, Fig. 2 is a side view showing the external appearance of the measuring device, and Fig. 3 is a main part of the measuring device. Fig. 4 is a circuit diagram showing an example of the electric circuit, Fig. 5 is a timing chart showing the operation of the electric circuit, and Fig. 6 is a block diagram conceptually showing the electric circuit. be. 1 is a clamp core, 8 is a switch, 9a and 9b are guide members, 19 is a current measurement and display circuit, 20 is a control circuit,
21 is a detection coil, and 22 is a current value hold circuit. In each figure, the same reference numerals indicate the same or the same corresponding parts. Patent applicant: Chubu Seiki Co., Ltd.
Chubu Electric Power Co., Ltd.

Claims (1)

[Claims] A clamp core having an annular shape and a part of the annular shape being able to be opened and closed; a detection coil provided in the clamp core; and a detection coil provided in the opening/closing portion of the clamp core that is pressed against the conductor to be measured. a conductor guide means for opening the core and taking the conductor to be measured into the inside of the clamp core; a switch controlled in conjunction with the opening/closing operation of the clamp core; a current measurement circuit that measures the current flowing through the conductor under test via the clamp core and the detection coil; and a control that controls the operation of the current measurement circuit at a predetermined time according to the operation of the switch. circuit and
and a current value hold circuit that holds the current value measured during the predetermined time.