JPH09318674A - Simplified photoelectric ammeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric ammeter easily and safely installed to measure a current of a wiring line. SOLUTION: A photoelectric ammeter includes a front plate type core incorporated case 1 incorporating a front plate type core 21 hooked in a high voltage wiring line 101 and disposed in one insulating rod 3, a photoelectric current sensor incorporated case 2 incorporating a photoelectric current sensor for detecting a magnetic field produced around the high voltage wiring line 101 by a current flowing through the high voltage wiring line 101 and outputting a light detecting signal and disposed in the gap part of the front plate type core 21 and a current display part 6 disposed in the other insulating rod 3 for converting the detecting signal into a current value, and the current value is displayed on the current display part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simplified photoammeter for easily measuring a current flowing through an electric wire by intensity modulation of light. Especially for electric power, the current of the high-voltage distribution line can be measured easily and in a short time by using an indirect tool.

[0002]

2. Description of the Related Art Distribution lines are widely spread radially from a substation to supply electric power, and the specifications are three-phase 660.
It is a high voltage of 0V. From the distribution line to each home, a voltage is dropped by a transformer and is drawn. Distribution lines that start from substations are managed according to demand by changing the thickness of the lines depending on the size of the load of consumers connected to the substation. However, the demand for electric power is increasing due to the development of urbanization and the sophistication of life, and daily management of distribution lines is important. Conventionally, the current of the distribution line is measured by detecting the secondary current obtained from both ends of the thin wire by passing the distribution wire through the through hole of CT where the thin wire is wound around the iron core. I've been
This is a structure called an electric ammeter. However, in the configuration of this ammeter, there is a possibility that the worker may be in danger if the detection part is in contact with the high voltage part and the instantaneous high voltage is applied to the distribution line on the primary side by the action of lightning or the like. It was

For this reason, electric ammeters have taken measures such as providing a thick resin layer in the current detecting section in order to increase the insulation strength of the detecting section. As a result, the risks were not eliminated at all, to the extent that they were alleviated. Due to this measure, the current detector becomes very heavy, which is not desirable for workers and distribution lines in which the current detector is installed.

FIG. 6 shows an electric ammeter which has been conventionally used and is a device sold by Takemoto Electric Keiki Co., Ltd. under the trade name "outdoor high voltage hook CT". The current measurement range is 0 to 1000 A, the maximum circuit voltage used is 6900 V, and the weight is about 3.5 kg.

A brief description of FIG. 6 will be given. High voltage distribution line 10
1, an electric ammeter 102 is installed. Electric ammeter 1
02, the high voltage hook portion 103 and the electric wire 104 extended from the high voltage hook portion 103 are connected to the circuit display portion 105. The connection is made by the connector 106 at the end of the wire.
The high-voltage hook portion 103 is composed of an iron core portion 107 for hooking on the high-voltage distribution line 101, a portion 108 for fixing the iron core 107, and a handle portion 109 having a high-voltage hook. The distance between the handle portion 109 having the high-voltage hook 103 and the iron core portion 107 for hooking the high-voltage distribution line 101 is about 20 cm. The worker's hand 110 is shown.

In this structure, when the high voltage hook portion 103 is hooked on the distribution line 101, the distance between the operator's hand 110 and the high voltage distribution line 101 is about 20 cm. Also high voltage distribution line 1
The distance between 01 and the operator's body is 70 to 80 cm. The head can only keep a distance of 40 to 50 cm. This situation cannot be said to be a safe work, and is in the range of dangerous work. In addition, when attempting to measure each of the three-phase distribution lines, it is necessary to move the work vehicle at a high place for measurement, which further increases the risk. Further, since it is an electric type, the electric wire 104 is connected to the circuit display unit 105, and the electric wire 10 is kept close to the measurement operator.
Since 4 is extended, when a high voltage is applied to the high-voltage hook 103 by deterioration of insulation or the high-voltage distribution line 101 due to lightning or the like, insulation breakdown occurs and even the measuring operator always feels the danger of high voltage. It will be.

FIG. 7 shows another device of the electric ammeter 121, and a brief description will be given. In addition, a product name “High-voltage current waveform sensor”, which is a different product from the above, is sold by Multi Measuring Instruments Co., Ltd. However, the detection CT unit 122 has a distance of about 20 cm between the core portion 123 that hooks the high-voltage distribution line 101 and the handle portion / grip portion 124 that opens and closes a part of the core 123. In this product, the detection CT unit 122 for measuring current and the output unit main unit 125 are configured to communicate with each other through an optical fiber cable 126. The total length of the CT unit 122 for detection is about 30 cm, and a donut-shaped core 123 for penetrating the high-voltage distribution line 101 is installed at the tip, and the core 1 is provided on the other side.
A grip portion and a grip portion 124 for opening and closing 23 are configured. A detection circuit and a circuit 127 for converting the detected signal into light are incorporated between the center of the core 123 and the upper part of the grip portion 124. The distance from the center of the core 123 to the grip 124 is about 20 cm.
When installed in No. 1, "Outdoor high pressure hook C" shown in FIG.
It has the same danger as "T". The output body 125 is separated and insulated by the optical fiber cable 126, so that the danger during measurement can be considered. But for detection C
Installing the T part 122 on the high-voltage distribution line 101 is a dangerous work.

For these reasons, it has been desired that current can be measured by a safe method or tool under a high voltage environment.

As a method of measuring current under a high voltage, which is such a problem, a method of measuring current using light is being put to practical use.

With the recent advances in optical element technology, optical applied measurement technology, and optical communication technology, optical sensor devices and miniaturized optical components for optical communication have been put into practical use or are being researched and developed aiming for practical use. . For example, the application of the optical sensor device to the electric power field has been steadily put into practical use by taking advantage of its characteristics such as high insulation and resistance to electromagnetic induction noise such as lightning (for example, National Technical Report).
Vol. 38 No2 p127 (1992)).

An ammeter using light is a method in which magnetic field lines are generated around an electric wire through which a current flows, which is detected by a magnetic field sensor using a magneto-optical crystal and converted into a current.

FIG. 8 shows a simple structure for current measurement by the optical magnetic field sensor. High-voltage distribution line 10 in the center of the horseshoe-shaped core 21.
1, and the optical magnetic field sensor 133 is installed in the void 132 of the horseshoe-shaped core 21. A light source unit 134 and an optical fiber 136 from a light detection unit 135 are connected to the optical magnetic field sensor 133, and the signal processing unit 1 is provided after the light detection unit 135.
37 is connected. When a current flows through the high-voltage distribution line 101, magnetic lines of force are generated around the line, but in this configuration, the core 2
1, the magnetic field lines are captured and a magnetic field H138 is generated and guided in the void 132 of the core 21. In the gap 132, a magnetic field H138 proportional to the electric current modulates the light that emerges and passes through the optical magnetic field sensor.

FIG. 9 shows the internal structure of the optical magnetic field sensor 131 using the optical parts installed in the void of the horseshoe-shaped core shown in FIG. In this configuration, the light incident fiber 14
The light that has entered from 1 receives the ferrule 142 and the lens 14
3, polarizer 144, magneto-optical crystal 145, analyzer 14
6, total reflection mirror 147, lens 143, ferrule 1
42 and the light emitting fiber 148. In this system, light is modulated by applying a magnetic field when passing through the magneto-optical crystal 145. 149 in the figure is a lens holder.

However, even in the case of the optical system measurement, it is difficult to easily install the detecting portion on the high-voltage distribution line, and it is necessary to use a work vehicle at a high place and to approach the high-voltage distribution line very close to it.

FIG. 10 shows a working condition when the electric ammeter shown in FIGS. 6 and 7 is installed on the high voltage distribution line 101. In addition, the optical ammeter shown in FIG.
It is necessary to carry out the mounting work close to the high-voltage distribution line 101 as shown in 0. The work is carried out by an aerial work vehicle 161, and a worker 163 gets into the bucket 162 at the upper part and installs a current detection unit 164 to the high-voltage distribution line 101, but the current detection unit 164 is small in size and has a grip portion. The distance between the worker's body and the high-voltage distribution line is close even if the device is installed with the arms extended. In addition, it can be said that the worker's head is in closer proximity and is in a dangerous situation. In addition, on the ground, a display unit 165 that displays a signal from the current detection unit 164 as a current is displayed.
Is installed. An electric wire 166 connects between the current detection unit 164 and the display unit 165.

[0016]

The above-described electric ammeter has the following problems.

When an ammeter is installed on the distribution line, it is in a very dangerous situation because the worker is close to the high voltage and the insulation distance is short. Therefore, it has been necessary to remove the hand from the current detection unit even for a short time and to keep a safe distance from the distribution line. However, due to the heavy weight of the core, it was necessary for an operator to support the distribution line even after it was installed on the distribution line. Furthermore, when the current detection signal is extended to the circuit section by an electric signal, the danger of instantaneous high voltage due to lightning or the like extends to the circuit section.

On the other hand, even in the conventional optical sensor device, in order to install it on the distribution line, it was necessary to approach the distribution line as close as possible to fix the device to the wire and pull down the optical fiber as in the case of the electric type. Conventional optical sensor devices are installed as a part of distribution line automation and are mainly aimed at detecting accident information on distribution lines.In load monitoring, only the installed distribution lines are used for measurement, and there is no automation. The location was impossible to measure. The conventional optical sensor device is basically installed for a long period of time, not simple installation.

However, in order to grasp the change of load and the like, it is necessary to measure the current in every place, and there has been a demand for a method capable of measuring the current of the distribution line with a simple and safe installation.
There has also been a demand for a simple measuring instrument that simultaneously measures not only load changes but also three-phase load conditions to detect unbalanced conditions.

[0020]

In order to solve the above-mentioned conventional problems, the present invention has a core built-in portion which is provided on one side of an insulating rod with a built-in core hooked on a distribution line, and the distribution line. A detection means built-in portion arranged in a void portion of the core and having a built-in photocurrent detection means for detecting a magnetic field generated around the distribution line by an electric current and outputting a light detection signal; To a current value to display the current value, and a current display unit arranged on the other side of the insulating rod, to provide a simplified photoammeter.

Further, the core built-in portion and the detection means built-in portion are
It is rotatably arranged by operating an insulating rod, and by operating the insulating rod, the detection means built-in portion is arranged in the void portion of the core or separated from the void portion of the core.

Further, a spacer corresponding to the size of the distribution line is provided in order to arrange the distribution line in the central portion of the core built-in portion.

Further, the photocurrent detecting means and the arithmetic unit are connected by an optical fiber, and the optical fiber penetrates through the insulating rod.

Further, the core built-in portion and the detection means built-in portion can be temporarily fixed at a fixed position.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a case containing a horseshoe-shaped core is fixed to one of the insulating rods. For fixing, the insulating rod penetrates the end of the case, and the insulating rod is freely rotatable at the end portion of the case. Further, a case in which the photocurrent sensor is stored is installed immediately below the case in which the horseshoe-shaped core of the insulating rod is stored. The case accommodating the photocurrent sensor is fixed to the insulating rod, and when the insulating rod is rotated, the case moves in the same manner. On the other side of the insulating rod, a current display section for displaying current is installed and fixed, and is connected to the photocurrent sensor by an optical fiber.

Detailed description will be given below with reference to the drawings. FIG. 1 shows the appearance of a simplified photoammeter according to an embodiment of the present invention, which is installed in a high-voltage distribution line and is in a state in which current measurement is possible.

The horseshoe-shaped core built-in case 1 and the photocurrent sensor built-in case 2 are fixed to one of the insulating rods 3. When the horseshoe-shaped core built-in case 1 and the photocurrent sensor built-in case 2 are combined, the photocurrent sensor case 2 is configured so that a region 4 through which the high-voltage distribution line 101 can penetrate is formed in the central portion of the horseshoe-shaped core built-in case 1. The current detecting section 5 is composed of the horseshoe-shaped core built-in case 1 section and the photocurrent sensor built-in case 2 section. A current indicator 6 is installed on the other side of the insulating rod 3. Two rubber umbrellas 7 are installed in the middle of the insulating rod 3 in order to prevent the entire surface from being wet by rainwater, so that the structure is safe even against sudden rain. The length of the insulating rod 3 is about 1.
It is about 5 m. High-voltage distribution line 1 for insulated rod 3
The positional relationship of 01 is indicated by a chain double-dashed line. The rotating operation of the insulating rod is performed by the grip portion 8. The insulating rod 3 is fixed to end portions of the horseshoe-shaped core built-in case 1 and the photocurrent sensor built-in case 2. Insulated rod 3 for case 1 with horseshoe core
The rotation is fixed so that it can be freely rotated. The photocurrent sensor built-in case 2 is completely fixed to the insulating rod 3 and is configured to rotate faithfully with respect to the rotation of the insulating rod 3. The horseshoe-shaped core-containing case 1 is fixed to the insulating rod 3 and fixed to the mandrel 9 with screws 10. The current indicator 6 is completely fixed to the other side of the insulating rod 3.

FIG. 2 shows a state in which the horseshoe-shaped core built-in case and the photocurrent sensor built-in case of the simplified photoammeter according to one embodiment of the present invention are rotated by 90 ° and separated by operating the insulating rod (the same as FIG. 1). Explain by number).

The lower grip portion of the insulating rod 3 is rotated to separate the photocurrent sensor built-in case 2 from the horseshoe-shaped core built-in case 1 and the horseshoe-shaped core built-in case 1 is rotated clockwise while the high-voltage distribution line 103 is hooked. It is a state in which it is turned about 90 ° in the opposite direction. The hand 11 of the grip portion 8 belongs to the operator.

FIG. 3 shows the positional relationship between the horseshoe-shaped core built-in case 1 and the photocurrent sensor built-in case 2 (FIG. 1).
The same number will be used for explanation). FIG. 3A shows a high voltage distribution line 1
It is sectional drawing of the state which combined the horseshoe-shaped built-in core case 1 and the photocurrent sensor built-in case 2 which are a current detection part with 01. FIG. 3B is a plan view showing a state where the horseshoe-shaped core built-in case 1 and the photocurrent sensor built-in case 2 are combined. The photocurrent sensor built-in case 2 comes to the installation position while rotating. FIG. 3B shows a rotation region on the side near the center 12 of rotation and on the side far from the center 12 of rotation when the case having a thickness rotates, by two-dot chain lines. With this rotation operation, the size of the photocurrent sensor built-in case 2 installed in the space 13 is set to be slightly smaller than the size of the space 13 of the case 1 with built-in horseshoe core. This is because the case is rotated on the same axis, so the width of the case with built-in photocurrent sensor viewed from the center of rotation, that is, the inner and outer rotational diameters viewed from the center of rotation is different and it is necessary to consider the dimensional margin. Is. However, when the case thickness on the rotating side is thin, the gap 14
Can be narrowed naturally.

Depending on the diameter of the high-voltage distribution line to be measured, it is possible to narrow the gap of the horseshoe-shaped core to narrow the width of the built-in case and the case containing the photocurrent sensor to improve the measurement sensitivity.

FIG. 4 is a perspective view of the current detecting portion of the simplified photoammeter according to one embodiment of the present invention, in which the horseshoe-shaped core built-in case and the photocurrent sensor built-in case are rotated by about 90 °. The horseshoe-shaped core 21 is internally fixed to the upper case 1,
A screw 10 is fixed to the insulating rod 3 at the end of the case.
When the horseshoe-shaped core 21 is installed in the case 1, the core penetration portion is aligned with the recess of the case 1. Void portion 22 of horseshoe core 21
In order to penetrate the electric wire in the state of being installed in the case 1, it is designed by adding the case wall thickness of the void portion to the diameter of the electric wire to be measured. However, the narrower the space between the voids 22, the more sensitively the current can be measured. Insulated rod 3 of case 1
An excessive rotation prevention stopper 23 of the case 2 with built-in photocurrent sensor is formed at the end opposite to. A photocurrent sensor 24 is built in the case 2 and the end position is completely fixed to the insulating rod 3. Further, the case 2 is configured so that an optical fiber 25 for inputting / outputting an optical signal to / from the photocurrent sensor 24 is built in and inserted into the insulating rod 3. The photocurrent sensor 24 is installed and fixed to the convex portion 26 of the case 2. Further, when the insulating rod is rotated, the stop pin operates in a state where the photocurrent sensor built-in case is installed in the horseshoe-shaped core built-in case void, and the stop pin operates when rotated by about 90 ° (Fig. (Not shown). This stopper pin has a structure in which a hard ball is pressed by a spring and is installed in a horseshoe-shaped core built-in case to fix the photocurrent sensor built-in case.

FIG. 5 shows a situation in which the current of a high-voltage distribution line is measured by using the simplified photoammeter according to one embodiment of the present invention. A worker 163 rides on the bucket 162 of the aerial work vehicle 161 and carries the simplified photoammeter 200 of the present invention to measure the current of the high-voltage distribution line.
Can work at a sufficient distance from the high-voltage distribution line 101, and safety can be improved. Further, there is a current indicator (not shown) on the grip of the insulating rod, and the current detector can be installed on the distribution line and can be measured at the same time.

When the bucket is located at the lower center of the high-voltage distribution line, the three-phase electric lines can be sequentially measured without moving the bucket.

The operation of measuring the current of the high-voltage distribution line will be described below. Prior to installation on the high-voltage distribution line 101, the case 2 with built-in photocurrent sensor is installed in the space of the case 1 with built-in horseshoe-shaped core, and the power switch of the current detection unit is turned on. Since no magnetic field is generated in the horseshoe-shaped core, the current is displayed as 0A. After that, the insulating rod 3 is rotated to separate the case with built-in photocurrent sensor from the void portion of the case (state of FIG. 2), the high-voltage distribution line 101 is sandwiched in the central portion of the case 1 with built-in horseshoe-shaped core, and insulated as it is. By rotating the rod 3, the case 2 with built-in photocurrent sensor is installed in the space of the case 1 with built-in horseshoe-shaped core as shown in FIG. In this state, the current display unit 6 displays the current value.
The indication is the current flowing through the high voltage distribution line. To end the measurement, rotate the insulating rod 3 in the opposite direction from the installation, and move from the void of the horseshoe-shaped core built-in case 1 to the photocurrent sensor built-in case 2
And remove the insulation rod from the high-voltage distribution line by lifting it up.

A horseshoe-shaped core 21 having a void 22
Is known to cause an error in current measurement depending on the position of the high-voltage distribution line 101 penetrating therethrough. However, using the simplified photoammeter of the present embodiment, a worker lifts the insulating rod 3 to penetrate the distribution line. By positioning the high-voltage distribution line 101 in the central part of the area 4, the error can be reduced. Here, in order to measure the current more accurately, a wire diameter conversion rubber may be used, and the high-voltage distribution line 101 may be arranged at the center of the horseshoe-shaped core 21 according to the size of the distribution line.

In the description of this embodiment, the insulating rod is about 1.5 m long, but it is possible to easily increase the total length. In that case, the operability deteriorates and the weight increases. However, it has the effect of increasing safety. In the present embodiment, the power source of the current indicator is battery-powered, so that the measurement can be performed only at the location of the bucket, and it is not necessary to route the power source line and the work is simple.

Further, in the present embodiment, the current display is of the direct reading type, but it is also possible to store and capture the current waveform of a fixed time in a storage medium such as a memory card. In that case, the current can be measured even in a configuration in which the worker removes the hand from the insulating rod and suspends it from the distribution line.

If the diameter of the distribution line is much smaller than the distribution line penetrating region 4 of the horseshoe-shaped core built-in case 1, accurate current display cannot be performed if it is displaced from the center of the core. In that case, it is possible to measure the current with a smaller error by using the above-mentioned electric wire diameter converting rubber for reducing the hole diameter of the through region of the case.

In this embodiment, the optical sensor is installed in the void 22 of the horseshoe-shaped core 21. However, the same effect can be expected in a structure in which a Hall element is installed for current detection. is there.

Further, in the present embodiment, the ammeter using the photocurrent sensor is used, but an electric field sensor or a voltage sensor using a capacitor voltage divider can be configured with the same configuration.

In the present embodiment, the display by the current display unit 6 is not limited to the digital display (direct reading) of the current value, and the change of the current value at any past time may be displayed by the current waveform. Often, such a display makes it possible to know not only the current value but also the change in the current value.

[0043]

With the constitution of the present invention, the following effects can be obtained.

(A) Since the photocurrent detection means is formed at the tip of the insulating rod, the current can be measured from a place distant from the high voltage distribution line, and the safety can be maintained.

(B) The photocurrent detection means is used to transmit a signal to the current display unit by an optical fiber, and the optical fiber is penetrated through the insulating rod to separate high-voltage impulses due to lightning or the like. You can work safely on the display.

(C) By using the insulating rod, the basket of the aerial work vehicle can be installed at a position where the three phases can reach, so that the three phases can be measured without moving the bucket, and the efficiency of current measurement can be improved. .

(D) It is known that the core having a void portion causes an error in current measurement depending on the position of the electric wire penetrating therethrough. The error can be reduced by lifting and positioning the electric wire in the central portion of the through hole.

Further, by using a spacer according to the size of the distribution line so that the wire is arranged in the center of the core, the measurement accuracy can be improved.

[Brief description of drawings]

FIG. 1 is an external view of a simplified photoammeter according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which a case with a horseshoe-shaped core and a case with a built-in optical sensor are separated from each other in the simplified photoammeter of one embodiment of the present invention.

FIG. 3 is a diagram showing a combined state of a case with a built-in horseshoe-shaped core and a case with a built-in photocurrent sensor according to an embodiment of the present invention.

FIG. 4 is an internal perspective view of a simplified photoammeter according to an embodiment of the present invention.

FIG. 5 is a diagram showing a situation in which the simplified photoammeter of one embodiment of the present invention is installed on a high-voltage distribution line in an aerial work vehicle to measure current.

FIG. 6 is a diagram showing a configuration of a conventional electric ammeter for signal transmission by electric wires.

FIG. 7 is a diagram showing a configuration of a conventional electric ammeter for signal transmission using an optical fiber.

FIG. 8 is a configuration diagram of conventional current measurement by light.

FIG. 9 is a block diagram of a conventional optical magnetic field sensor.

FIG. 10 is an explanatory view of a situation in which a conventional ammeter is installed on a high-voltage distribution line in an aerial work vehicle to measure current.

[Explanation of symbols]

 1 Case with built-in horseshoe-shaped core 2 Case with built-in optical current sensor 3 Insulation rod 4 Penetration area of distribution line 5 Current detection part 6 Current display part 8 Grip part 12 Center of rotation 13 Void part with built-in horseshoe core 14 Gap 21 Horseshoe core 22 Void of horseshoe core Part 23 Excessive rotation prevention stop 24 Photocurrent sensor 25 Optical fiber

Claims (5)

[Claims] Claim: What is claimed is: 1. A core built-in portion having a core to be hooked on a distribution line and arranged on one side of an insulating rod, and a magnetic field generated around the distribution line by a current flowing through the distribution line to detect light. A detection means built-in portion which is arranged in the void portion of the core and has a built-in photocurrent detection means for outputting a signal;
A simplified photoammeter comprising: a current display unit arranged on the other side of the insulating rod to convert the detection signal into a current value and display the current value. 2. A core built-in portion and a detection means built-in portion are rotatably arranged by operating an insulating rod, and the detection means built-in portion is placed in a void portion of the core by operating the insulating rod. The simplified ammeter according to claim 1, wherein the simplified ammeter is configured to be separated from the void portion. 3. A simplified photoammeter according to claim 1, wherein a spacer corresponding to the size of the distribution line is provided to arrange the distribution line in the central portion of the core built-in portion. 4. A simplified photoammeter according to claim 1, wherein the photocurrent detecting means and the arithmetic unit are connected by an optical fiber, and the optical fiber penetrates through the insulating rod. 5. The simplified photoammeter according to claim 1, wherein the core built-in portion and the detection means built-in portion can be temporarily fixed at a fixed position.