JP3148229B2 - Load measurement method for overhead wire - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for measuring a load of an overhead line such as an overhead power transmission line or an overhead ground wire and a load such as a snowfall weight.

[Prior Art] In order to measure the load of an overhead wire such as the weight of snow on an overhead power transmission line or the tension of an overhead ground wire, as shown in FIG. A load cell 21 for measuring the load due to the weight of the transmission line D supported by the arm is mounted between the upper part of the insulator string C and the arm B, and the load due to the tension of the overhead ground wire E suspended on the top of the tower is measured. The load cell 22 is attached to the overhead ground wire E, and the insulated conductors 23 and 24 connected to the load cells 21 and 22 are pulled down along the steel tower column and the amplifier 25 is lowered.
To amplify the output of the load cell and record it with the recorder 26 to measure the load due to the weight of the transmission line D and the load due to the tension of the overhead ground wire E. Reference numeral 27 denotes a power supply such as a solar cell or a battery. The amplifier 25 and the recorder 26 are grounded at 28 or 29.

The load cell is generally provided with an insulating material on a steel rod 30 having bolt mounting holes 31 at both ends as shown in FIG.
A tensile load cell to which a strain gauge 33 covered with 32 is attached is used, and the insulated conductor 23 or 24 is connected to the strain gauge 33.

[Problems to be Solved by the Invention] In the conventional load measuring method as described above, when a lightning strike occurs on an overhead ground wire or a tower, the potential of the tower rises due to the tower impedance or the ground resistance of the tower, and the load cells 21 and 22 There is a problem that a large potential difference is generated between the mounting point and the earths 28 and 29, and dielectric breakdown occurs in the insulating coating strain gauge 33 and the insulated conductors 23 and 24 of the load cell, so that the load cannot be measured.

An object of the present invention is to provide a method for measuring the load of an overhead wire in which the above-described insulation breakdown does not occur.

[Means for Solving the Problems] To achieve the above object, the overhead wire load measuring method of the present invention is to measure the weight load and the tensile load of overhead wires such as overhead transmission lines and overhead ground wires supported by a steel tower. In order to measure, the overhead wire load detection device and the detection electric signal input / output device are arranged on the ground side and installed on a steel tower supporting the overhead wire, and the electric power output from the detection electric signal input / output device is measured. A method of converting a signal into an optical signal or a wireless signal, transmitting the optical signal or the wireless signal to a recording and display device or the like by an optical fiber cable or wirelessly, and measuring the load on the overhead wire; This method measures the overhead wire load by making the height of the position where the input / output device is installed on the tower substantially equal to the height of the position where the load detection device is installed, making the ground potentials of both of them substantially equal, and (2) ) The above load detecting device It provided insulated from the installation frame a load cell provided in, which has a bypass portion to the load cell installation frame, which is constituted by a flexible metal (3) the bypass section.

[Operation] The load detection device includes a load cell, and the load cell receives a load on the overhead wire and outputs a detection electric signal corresponding to the load.

The detection electric signal input / output device amplifies the input detection electric signal and outputs the amplified electric signal to the electric / optical signal conversion device or the wireless signal transmission device.

The converted optical signal or wireless signal is transmitted to a recording and display device or a remote monitoring device or the like below the tower by an optical fiber cable or wirelessly to be recorded and displayed.

Since the height of the installation position of the load detection device and the installation position of the detected electric signal input / output device are almost equal, the ground potentials of both are almost equal, and there is almost no potential difference between the two, so there is no damage to the device. .

At a position at a height substantially equal to the height at which the detection electric signal input / output device is installed on the tower, the electric output signal of the detection electric signal input / output device is converted into an optical signal or a radio signal, and the converted signal is converted. Since optical signals are transmitted to recording and display devices by optical fiber cable or wirelessly, electric wires are not used, so even if the tower potential rises due to tower impedance during a lightning strike, the load detector and the detected electrical signal input / output device are also used. Does not damage.

Further, since the load cell is provided insulated and the bypass portion is provided in the load cell installation frame, even if lightning strikes, the ground fault current flows through the bypass portion and does not flow to the load cell, so that damage to the load cell is prevented.

In addition, since the bypass portion is made of a flexible metal, it can follow the movement of the load cell installation frame, so that no damage occurs. [Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a state in which a measuring instrument or the like is installed on a tower in the present invention, and FIG. 2 shows an enlarged view of a load detection device attached to a tower arm shown in FIG.
Denotes an arm, C denotes a suspended insulator series suspended from the arm B, and D denotes a transmission line held by a clamp F at a lower end of the insulator series.

Reference numeral 1 denotes an example of a load detecting device for a load cell mounted between the insulator at the upper end of the insulator and the arm B, and the upper U-shaped frame 4 is suspended by the horizontal bolt 3 suspended by the suspension rod 2 mounted on the arm B. The upper U-shaped frame 4 is supported by the upper U-shaped frame 4, the upper bottom 7 of the lower inverted U-shaped frame 6 is opposed to the lower U-shaped frame 6, and the upper U-shaped frame 4 is suspended by a support rod 8 attached to the lower inverted U-shaped frame 6. The lower rod 9 is suspended.

A load cell 10 using a strain gauge, a potentiometer, or the like is interposed between a lower bottom portion 5 of the upper U-shaped frame 4 and an upper bottom portion 7 of the lower inverted U-shaped frame 6.

This load cell 10 and the upper U-shaped frame 4 as its installation frame
The load cell 10 is provided insulated from the installation frame by interposing a plastic insulating plate 11 between the load cell 10 and the lower bottom 5.
This insulation prevents a ground fault current from flowing to the load cell 10.

Also, a bypass portion 12 made of a flexible metal is connected to the side plate portion 4 'of the upper U-shaped frame 4 and the side plate portion 6' of the lower inverted U-shaped frame 6, which are the installation frames of the load cell 10. As a result, the ground fault current does not flow through the load cell 10 but flows through the bypass unit 12.

In addition, the upper U-shaped frame 4 and the lower inverted U
Even if the character frames 6 move slightly relative to each other, the bypass portion 12 follows the movement because it is made of a flexible metal.

The above embodiment is an example in which a compression type load cell is used as the load cell 10, and the lower bottom 5 and the lower inverted U of the upper U-shaped frame 4 are used.
When a compressive load is applied between the upper and lower portions 7 of the character frame 6, a detected electric signal corresponding to the amount of strain due to the compressive load is obtained, but an appropriate load cell such as a tension type can also be used.

On a tower member located at substantially the same height as the position of the load detection device 1 attached between the tower arm B and the insulator string C,
An amplifier 13 serving as an input / output device of a detected electric signal of the load detecting device 1, an E / O 14 of an electric / optical converter for converting the amplified electric signal into an optical signal, and a power supply 15 such as a solar cell and a battery are installed. An insulated conductor 16 (shown by a broken line) derived from the load cell 10 is connected to the amplifier 13, and the optical signal output of the E / O 14 is transmitted through the optical fiber 17.

The optical fiber 17 is pulled down along the tower column material and connected to an O / E (optical / electrical exchange device) 18 installed at the lower part A 'of the tower. And the like, and if necessary, a power source such as a solar cell or a battery is also provided at the lower part A 'of the tower. Alternatively, the optical fiber 17 is connected to an optical fiber of an overhead ground wire (OPGW) containing an optical fiber which is stretched on the top of the tower A and transmitted as an optical signal to a remote monitoring point.

As described above, when transmitting the amplified electric signal of the detected electric signal input / output device of the load detecting device 1 to a recording display device or the like, the E / O 14, the optical fiber 17, and the O / E 18 are used as an optical signal and transmitted. Instead, it is possible to transmit wirelessly, install a wireless transmitter instead of E / O 14, install a wireless receiver instead of O / E 18, and transmit wirelessly without using the optical fiber 17. Good.

The top metal of the insulator at the upper end of the insulator chain C is suspended from the suspension rod 9 at the lower end of the load detector 1 supported by the tower arm B, and is suspended by the suspension clamp F suspended by the insulator at the lower end of the insulator chain. The transmission line D is suspended.

In the load detecting device 1 installed as described above, the lower inverted U-shaped portion 6 is pulled downward by the load due to the weight of the transmission line D suspended by the suspension clamp F, and the upper bottom portion 7 thereof faces the upper surface of the load cell 10. Since the signal is compressed, an electric signal corresponding to the amount of compressive strain of the load cell due to the transmission line load is input to the amplifier 13 installed on the tower arm B through the insulated conductor 16 and converted into an optical signal by the E / O 14 and the optical fiber 17 is converted. The load on the transmission line is recorded by a recorder 19 installed at the bottom of the tower. Alternatively, when this converted optical signal is transmitted to a remote monitoring point via an optical fiber overhead ground wire stretched over the top of the tower, the load of the transmission line is recorded and measured at the remote monitoring point.

When there is snow on the transmission line D, the load cell 10 is compressed by the load obtained by adding the weight of the snow, and the snow load is measured.

Since the input / output device of the detected electric signal is installed at a position of the tower height substantially equal to the position of the tower at which the load detecting device 1 is mounted, the load detecting device 1 and the input of the detected electric signal are input. Since the output device has substantially the same potential with respect to the ground, there is almost no potential difference between the two, so that the device is not damaged.

Also, when a lightning strike occurs, the potential of the tower rises due to the tower impedance and the grounding resistance, causing a large potential difference between the tower and the transmission line, damaging the insulator string and causing a ground fault current to flow to the load detector 1, but the upper U-shaped frame. Since the flow does not flow to the load cell 10 which is insulated by the insulating plate 11 and flows through the bypass portion 12 connecting the lower U-shaped frame 4 and the lower inverted U-shaped frame 6, the load cell 10 is not damaged.

In addition, since the output signals of the amplifier 13 and the E / O 14 are guided to the lower part of the tower by the optical fiber 17 instead of the conducting wire, they are not damaged even if the potential of the tower rises due to lightning strike or the like. There is no damage to the device when transmitting wirelessly.

The above-mentioned embodiment is an embodiment in which the load due to the weight of the transmission line D suspended and supported by the insulator string C is measured, but the load due to the tension of the overhead ground wire stretched on the top of the steel tower is measured. In the case, a load detector equipped with a load cell for measuring a tension load is attached to an overhead ground wire, and as in the above-described embodiment,
The amplifier, E / O and its power supply are installed near the top of the tower at the height of the load detector, and the optical signal output of the E / O is a recorder installed at the bottom of the tower with the optical fiber along the tower column. It is transmitted to a remote monitoring point as a light signal via an optical fiber of an overhead ground wire containing an optical fiber stretched on the top of the tower, or recorded and displayed, or transmitted wirelessly. To display the record.

[Effects of the Invention] As described above, the present invention arranges an overhead wire load detection device and an input / output device for the detected electric signal on an overhead wire support tower on the ground side, and A method of converting an output electric signal into an optical signal or a wireless signal, and transmitting the optical signal or the wireless signal to a recording display device or the like by an optical fiber cable or wireless to measure a load on an overhead wire, wherein the detected electrical signal is Since the height of the installation position of the input / output device is substantially equal to the height of the installation position of the load detection device and the ground potential of both is approximately equal to measure the overhead wire load, the detection electric signal input / output device There is no damage, and the load cell of the load detector is insulated and a bypass is provided.Even if lightning strikes, ground fault current does not flow through the bypass and the load cell is not damaged. No et al.

Further, since the bypass portion is made of a flexible metal, it can follow the movement of the load cell installation frame, so that no damage occurs.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of the present invention, FIG. 2 is a view showing an attached state of a load detecting device, FIG. 3 is a view showing a conventional example, FIG.
FIG. 1 shows an example of a conventional load cell. 1; load detector 3 to 8; load cell installation frame 10; load cell 12; bypass section 13, 14; detected electric signal input / output device 19; recording and display device

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-114515 (JP, A) JP-A-60-28935 (JP, A) JP-A-60-262104 (JP, A) JP-A-1- 300624 (JP, A) Hikaru 1-109213 (JP, U)

Claims (3)

(57) [Claims] An overhead wire load detecting device and an input / output device for an electric signal detected by the overhead wire are disposed on an overhead wire supporting tower on the ground side, and an electric signal output from the electric signal input / output device is converted into an optical signal. Or converting the optical signal or the wireless signal to a recording and display device or the like by transmitting the optical signal or the wireless signal to a recording and display device or the like wirelessly to measure the load on the overhead wire. A method for measuring the overhead wire load, wherein the overhead wire is measured by making the height substantially equal to the height of the installation position of the load detection device, and making the ground potentials of the two approximately equal. 2. The overhead wire load measuring method according to claim 1, wherein the load cell of the load detecting device is provided insulated from the installation frame, and the installation frame is provided with a bypass portion. 3. The overhead wire load measuring method according to claim 2, wherein the bypass portion is made of a flexible metal.