JPH0526907A - Monitoring apparatus for distribution line - Google Patents

Abstract

PURPOSE:To reduce a change in characteristics due to a change in the potential of a conductor element such as a potential divider caused by rainfall or the like by a method wherein a distance between cases holding a distribution line between and fixing it and a core of high permeability surrounding the distribution line is made to be equal or larger than a distance between the core and the distribution line. CONSTITUTION:Upper and lower cases 18 and 19 of the present apparatus hold a distribution line 2 between and fix it. An optical current sensor 11, a voltage sensor 9, a capacitor potential divider and inner and outer electrodes 16 and 17 thereof are disposed inside the case 19 and an electrode 20 is disposed in the bottom part thereof, while a horseshoe-shaped core 12 having a gap 13 is provided. Incidence and emission of light on and from the sensors 9 and 11 are conducted through an optical fiber 15. In this constitution, the shortest distances to the potential divider and the electrode 20 incorporated are made to be equal or longer than the shortest spacing between the electrodes 16 and 17 and, besides, the short distance between the core 12 and the outer surface of the case 18 is made to equal or longer than the shortest distance between the core 12 and the distribution line 2. In this way, the effect of a change in the potential of the core on the potential divider and the electrode 20 can be reduced even when contamination or damage is caused by snow or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distribution line monitoring device, which is installed to monitor the operating condition of a distribution line or a transmission line having a relatively high voltage. To easily and accurately detect.

[0002]

2. Description of the Related Art In today's society, momentary power outages are unacceptable and the situation of power transmission or distribution is constantly grasped.
It is necessary to predict the occurrence of accidents or prevent them from occurring.

In response to such a demand, conventionally, a distribution line monitoring device used for an overhead power distribution line has a zero-phase current transformer (referred to as ZCT) or a built-in relay switch installed on a utility pole. It was electrically measured and monitored by a zero-phase transformer (called ZPT). However, in this method, since the electric lines to which a high voltage is applied are put together in the relay switch,
Insulation becomes very difficult. Further, since a high voltage is constantly applied, it cannot withstand long-term reliability.
In the past, many accidents occurred in this area, and it was necessary to regularly replace the distribution lines in the relay switch to prevent them.

FIG. 7 shows the installation situation of the relay switch on the utility pole. The three-phase distribution line 2 is installed on the telephone pole. The distribution line 2 is fixed to and pulled by the armor 4 on the utility pole by the tension insulators 3 provided at regular intervals on the utility pole 1.

In FIG. 7, the distribution line 2 is in a slack-free state, and a device such as a relay switch 5 is installed between the next connections. The three-phase distribution line 2 indicated by the arrow 6 is connected to the three-phase distribution line 2 indicated by the arrow 7 through the insulator 3 and the relay switch 5. Inside the relay switch 5 shown in FIG.
A PD and a distribution line cutoff switch (both not shown) are built in, and the ZCT or ZPD detects an abnormality in the middle of the distribution line, and cuts off communication communication to the substation or switch. Such an abnormality is configured to be transmitted to a substation or the like through a communication line 8 installed in the middle of the electric pole 1.

[0006]

[Problems to be Solved by the Invention] As shown in FIG.
The three distribution lines 2 are guided into the relay switch 5 and further Z
Focus on areas such as CT. Even in the case of ZPT, it will be connected via a capacitor or the like. For this reason, the interphase voltage of the distribution line is concentrated in a very narrow place, and insulation cannot be maintained depending on deterioration due to long-term use or the airtight state of the relay switch 5, resulting in short circuit between lines or distribution line In some cases, the cause of the accident itself occurred due to the progress of equipment short circuits.

The distribution line monitoring device constantly monitors the current and voltage flowing through the distribution line in order to detect or predict an accident. This information is
It must be stable and stable under all weather conditions. Therefore, it is desired that even when this device is configured differently, it is not subject to climate change as in the conventional relay switch. The main changes in climate are wetness due to rain, snowfall, etc.In addition, if the configuration is such that each of the three-phase distribution lines is individually monitored, it is required that the variation in characteristics be small enough to be ignored in the detection means. To be done.

The present invention aims to overcome such problems and obtain a distribution line information by installing a monitoring device in a state where three-phase distribution lines are installed at regular intervals.

[0009]

In order to achieve the above-mentioned object, the present invention comprises a case which is composed of two parts, an upper part and a lower part, for sandwiching and fixing a distribution line, and a high position which is arranged inside the case and which surrounds the distribution line. It is composed of a magnetic permeability core and magnetic flux detecting means for detecting a change in magnetic flux collected by the core, and the shortest distance between the core and the outer surface of the case is equal to or more than the shortest distance between the core and the distribution line. Is a distribution line monitoring device.

Further, a case composed of two parts, an upper part and a lower part, for fixing the distribution line by sandwiching it and at least one of the two cases, the voltage divider for dividing the stray capacitance between the distribution line and the ground into a capacitor. A voltage detecting means for detecting a voltage divided by the voltage divider, a high magnetic permeability core that circulates around a distribution line, and a magnetic flux detecting means for detecting a change in magnetic flux collected by the core, In the distribution line monitoring device, the core and the voltage divider are arranged such that the shortest distance between them is equal to or more than the distance between the conductors of the voltage divider.

Further, a case composed of two parts, an upper part and a lower part, for fixing the distribution line by sandwiching it and at least one of the two cases, the voltage divider for dividing the stray capacitance between the distribution line and the ground into a capacitor. A voltage detecting means for detecting the voltage divided by the voltage divider, a high-permeability core that circulates around the distribution line, a magnetic flux detecting means for detecting a change in the magnetic flux collected by the core, and the voltage divider. It consists of a conductor installed in the case body on the side where
The outer conductor of the capacitor voltage divider is connected to the conductor installed in the case body on the side that houses the voltage divider, and the shortest distance between the core and the voltage divider and the shortest distance between the core and the conductor installed in the case body. Is a distribution line monitoring device characterized in that both are arranged so as to be equal to or more than the distance between the conductors of the voltage divider, and further, the core includes an upper case body and a lower case body for accommodating the voltage divider. The distribution line monitoring device is characterized in that it is divided near the boundary and is connected between the divided cores via an insulator.

More specifically, an optical voltage / current sensor is housed in a case body, and the case body is provided with a recess so that it can be installed on a distribution line. The case body is located on the lower side, and another case body having a distribution line installation concave portion is sandwiched and fixed from above by the distribution line. Inside the lower case body, a capacitor voltage divider for dividing the stray capacitance between the distribution line and the ground is constructed by two conductors and built in. Furthermore, the outer conductor of the capacitor voltage divider is connected to the conductor installed on the inner bottom wall surface of the case body, and the optical voltage sensor has a structure in which the outer conductor of the capacitor voltage divider is connected to the conductor of the case body wall surface. Is installed. The connection of the voltage application to the voltage sensor is performed from the inside of the two conductors and the conductor portion connected to the conductors installed on the wall surface of the lower case body.

The high-permeability silicon steel core for the current sensor is fixed around the distribution line so that the gap of the core is located at the mounting position of the current sensor.

The sensor portion of the distribution line monitoring apparatus of the present invention is directly mounted on the distribution line, and is directly wet by rain, snowfall, etc., or there is snow on the case. It is necessary to make the case body structure so that the output of the internal capacitor voltage divider is not affected even under such a condition. For that purpose, the positional relationship between the core and the capacitor voltage divider housed inside and the size of the case body are important, and the shortest distance between the core and the outer surface of the case body is equal to or more than the shortest distance between the core and the distribution line. To do.

Both the shortest distance between the core and the voltage divider and the shortest distance between the core and the conductor installed in the case body are both equal to or greater than the inter-conductor distance of the voltage divider.

Further, the core is divided in the vicinity of the boundary between the lower case body and the upper case body, and an insulator or the like is arranged at the dividing position so that the divided cores are magnetically coupled. Avoid electrical connection.

[0017]

With the above structure, according to the present invention, by changing the shape of the outer case of the optical sensor of the distribution line monitoring device and the arrangement of the core for the current sensor, a change in the floating capacitance between the ground due to contaminants such as rain or snow is caused. To reduce fluctuations in the characteristics of the distribution line monitoring device due to changes in the potential of conductors such as voltage dividers for voltage sensors.

[0018]

The present invention will be described in detail below. First, the outline of the optical voltage sensor will be briefly described. The optical voltage sensor utilizes the Pockels effect, and detects the electric field by detecting the amount of change in the birefringence of the crystal with respect to the electric field when light passes through the Pockels element. In the present invention, the current sensor is housed in the case body at the same time as the voltage sensor, so an outline of the optical current sensor will also be described.

The optical type current sensor utilizes the Faraday effect and detects the magnetic field generated around the electric current when a current flows through the electric line by the rotation angle of the light passing through the Faraday element. FIG. 5 shows a schematic diagram in which such a voltage sensor and a current sensor are integrated and installed on a distribution line.

More specifically, a horseshoe-shaped core 12 having a gap 13 for a current sensor is installed on the distribution line 2, and the optical current sensor 11 is arranged in the gap 13. The optical voltage sensor 9 is provided with a capacitor voltage divider 10 for dividing stray capacitance, and two conductors of the voltage divider are connected to terminals (not shown) of the optical voltage sensor 9.
An optical fiber 15 for incidence and emission is connected to the optical voltage / current sensor, and one optical fiber cable 14 is formed midway and guided to a connector 19 at the end.

FIG. 6A shows an equivalent circuit between the distribution line, the voltage sensor and the ground. A capacitor voltage divider 10 and a voltage sensor 9 are installed between the distribution line 2 and the ground 42. C ₁₄
3 is an electrostatic capacitance between the conductor of the distribution line 2 and the inner electrode of the capacitor voltage divider 10. C ₂ 44 is the capacitance between the inner and outer electrodes of the capacitor voltage divider 10.
C ₃ 45 is a capacitance between terminals of the voltage sensor. C ₄ 46 is an electrostatic capacitance including the air formed between the outer electrode and the earth divider capacitive divider.

This C₁ 43, C₂ 44, C₃ 45, C_Four 
C out of 46₁ 43, C₂ 44, C ₃ 45 is a component
C can be determined by composition_Four Only 46 is affected by atmospheric humidity
And it changes depending on where the earth part, which is the ground, comes
It is a part. Also, the outer electrode of the capacitor voltage divider 10 and the large
A water film or snow that could become an electrode was formed between the ground.
Likewise C_Four The value of 46 fluctuates, and eventually the capacitor
The divided voltage output of the voltage divider 10 changes. Example
Is this C_Four Even if the capacitance value of 46 fluctuates, it will be affected
Get the divided voltage output from the capacitor voltage divider 10 without
It is what

FIG. 6 (b) shows a place where the equivalent circuit is considered to change due to external influence. If the side surface or the outer periphery of the distribution line monitoring device gets wet, the position of the outer electrode of the capacitor voltage divider with respect to the ground and the high-potential portion are confused and fluctuate. At that time, the capacitance between the earth and the earth becomes a variable capacitance such as C ₄ '47 due to a change in the area facing the earth. As described above, the present invention takes measures against a portion affected by water such as rain and snow.

A detailed example of the present invention will be described below. FIG. 1 shows a configuration perspective view of a distribution line monitoring apparatus according to a first embodiment of the present invention. Distribution line 2 is lower case 1
9 and the upper case body 18 are sandwiched between the upper and lower sides. Inside the lower case body 19, an optical current sensor 11, a voltage sensor 9, and an outer electrode 1 of a voltage sensor parallel capacitor voltage divider are provided.
6 and the inner electrode 17 are installed. The outer electrode 16 and the inner electrode 17 are connected to the voltage sensor 9 by a conductor wire 21. An electrode 20 is arranged inside the bottom of the lower case 19 and is electrically connected to the outer electrode 16. The current sensor horseshoe-shaped core 12 circulates around the distribution line 2, and is installed so that the current sensor 11 inside the lower case is located at the position of the gap 13. Light entering and exiting the current sensor 11 and the voltage sensor 9 is performed by the optical fiber 15, and is connected to the optical fiber cable 14 introduced from the outside in the lower case body 19. The inner electrode 17 is close to the distribution line 2, and the shortest distance between the inner electrode 17 and the outer electrode 16 is about 10 mm, the shortest distance between the core 12 and the distribution line 2 is about 5 mm, and the shortest distance between the core 12 and the outer surface of the upper case body. The shortest distance between the core and the capacitor voltage divider is about 20 mm, the shortest distance between the core and the electrode 20 is about 20 mm, and the distribution line 2 does not pass through the center of the core 12. By separating the core 12 and the upper and lower case bodies from each other in this way, even if there is snow or water wet on the outside, since they are not separated from each other, they are electrically weakly coupled to the capacitor voltage divider and the electrode 20. It is possible to reduce the potential change of the existing core 12. Further, by separating the core 12 and the capacitor voltage divider and the core and the electrode 20 from each other, the influence of the potential change of the core 12 on the capacitor voltage divider and the electrode 20 due to contamination can be reduced. However, since the stains due to weather such as rainfall or snow are concentrated on the upper and side portions, it is sufficient to separate only the upper case body 18 from the core 12.

FIG. 2 is a sectional view of the distribution line monitoring device of the present invention (AOB-A'O 'in FIG. 1) for showing the electric field distribution according to the positional relationship of each component inside the case body of this embodiment.
B '). However, the electric field distribution in the figure is distribution line 2
The electric field 22 is at a high electric potential, and the electric field 22 is
Starting from, proceed toward the earth 23. Further, minute electric field changes and the like which are not related to the present invention are omitted for convenience of explanation.
The electric field distribution on the upper side of the distribution line 2 advances in the vertical direction of the distribution line 2 as illustrated. On the other hand, the electric field distribution on the lower side of the distribution line goes straight in the direction of the capacitor voltage divider from the distribution line 2 to the outer electrode 16 except for the ends of the electrodes, but inside the bottom part of the outer electrode 16 and the lower case body 19. The electrode 20 provided on the
Since they are connected with each other, the outer electrode 16 and the electrode 20 are electrically conductive.
There is no electric field between them. Then, the electric field again proceeds from the electrode 20 toward the ground 23. In the direction away from the capacitor voltage divider, the electric field goes straight from the distribution line 2 toward the ground 23 as in the upper direction. However, the electric field distribution is complicated in the vicinity of the capacitor voltage divider end, and there is an electric field leaking laterally from the ends of the inner electrode 17 and the outer electrode 16 as shown in the figure, which is combined with the electric field traveling straight from the distribution line 2. If the distance from the core 12 to the outer surface of the case, the capacitor voltage divider, and the electrode 20 is set apart as in the present embodiment, the influence of external pollution such as rainfall or snow cover the inside of the lower case body via the core. It is possible to prevent the capacitor voltage divider from being reached.

In FIG. 3, the case body shape is fixed, and the distance between the distribution line 2 and the core (d in FIG. 2) and the distance between the distribution line 2 and the outer surface of the upper case body 18 (h in FIG. 2) are used as variables. In this case, the degree of influence of pollution is shown. The horizontal axis represents the distance d between the distribution line 2 and the core 12 (negative correlation with the distance between the core 12 and the outer surface of the upper case body 18), the vertical axis represents the degree of influence of contamination, and the curve 24 represents the distribution line 2 and the upper case body 18. Shows the difference in pollution influence degree depending on the distance h, and the larger h is, the smaller the pollution influence degree is.
As can be seen from the figure, the larger h is, the smaller the pollution influence degree is and the better the characteristics are. However, in consideration of the appearance, weight and the like, in this example, the curve on the point A was used. Regarding the relationship between the distance d between the distribution line 2 and the core 12 and the degree of pollution influence, the point where the point d is large is also high in the degree of pollution influence, and the smaller it is, the smaller it is and the smaller the point A is, the minimum value is shown. The smaller the value, the greater the pollution impact. This is because at point B, the core 12 and the capacitor voltage divider 10
Is small, the electric coupling between the core 12 and the capacitor voltage divider 10 is relatively strong, and the potential change of the core 12 due to pollution affects the capacitor voltage divider, and in the vicinity of the point A, the distance from the core 12 to the capacitor voltage divider and the electrode 20 is increased. Since the distances are different, the influence of external pollution is not transmitted to the voltage divider.
Where d is smaller than point A, this time the core 12 and the electrode 20
This is because the effect of pollution will appear again because the distance between the two becomes shorter.

As described above, according to this embodiment, the relative position of the core 12 and the electrodes 16 and 17 of the capacitor voltage divider can be controlled to reduce the potential change due to the disturbance of the electric field due to rainfall, snowfall, etc. be varied capacitance value of C ₄ 46 is, it is possible to obtain a divided voltage output from the capacitor divider 10 without being affected.

Next, FIG. 4 is a perspective view showing the configuration of the distribution line monitoring apparatus according to the second embodiment of the present invention. Since all are the same as the first embodiment except the arrangement of the core 12 and the current sensor 11,
Only different parts will be described below. The core 12 is arranged so that the distribution line 2 is at the center, divided near the boundary between the upper case body and the lower case body, and the spacer 25 such as an insulator is arranged in the divided portion to divide the core 12 into upper and lower parts. It weakens the electrical connection between the top and bottom. Here, the thickness of the spacer 25 is a polyethylene sheet having a thickness of about 0.3 mm to minimize the decrease in the strength of the magnetic field.

As described above, according to this embodiment, the core 12
The core 12 is divided into two to weaken the electrical coupling between the upper and lower parts of the core, so that the core 12 is frequently damaged by the upper and upper parts.
It is possible to prevent the change in the electric potential of the upper part from being transmitted to the capacitor voltage divider in the lower case body 19, and prevent the change in the electric potential of the core 12 due to the frequent contamination of the upper side to be transmitted to the capacitor voltage divider in the lower case body. be able to.

In the present invention, a plurality of or a part of the structures shown in the embodiments are adopted, but the inventions of each invention may be used alone or in combination. In the present embodiment, the description has been made with only one distribution line, but the same configuration and effect can be obtained when each is installed in a three-phase distribution line.

Further, the electrode shape of the voltage sensor voltage divider may be arbitrary as long as the required voltage intensity can be taken out.

[0032]

As described above, the present invention has the following effects. That is, in a distribution line monitoring device for detecting voltage or current by an optical method, it is possible to reduce climate change, particularly characteristic change due to wetness by rainwater, characteristic change due to snowfall, and to provide a stable device. . Further, according to this configuration, it is possible without making the device shape particularly large.

[Brief description of drawings]

FIG. 1 is a configuration perspective view of a distribution line monitoring device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the device.

[Fig. 3] Correlation diagram of placement of each part and degree of pollution influence

FIG. 4 is a distribution line monitoring device according to a second embodiment of the present invention.

FIG. 5 is a conceptual diagram of the same device using an optical voltage sensor and current sensor.

FIG. 6 is an equivalent circuit diagram between the distribution line on the voltage sensor side of the device, the capacitor voltage divider, and the ground, and an equivalent circuit diagram when the distribution line, the capacitor voltage divider, and the ground are externally affected.

[Fig. 7] Installation view of a conventional relay switch with a built-in zero-phase current transformer on a utility pole

[Explanation of symbols]

1 utility pole 2 distribution lines 3 Zhang insulator 4 armor 5 relay switches 8 communication lines 9 Voltage sensor 10 condenser voltage divider 11 Current sensor 12 High permeability horseshoe-shaped silicon steel core 13 Gaps 14 Optical fiber cable 15 Optical fiber core 16 Outer electrode 17 Inner electrode 18 Upper case body 19 Lower case body 20 electrodes 21 conductor wire 22 electric field 23 Earth

Claims (4)

[Claims] 1. A case composed of two parts, an upper part and a lower part, for sandwiching and fixing a distribution line, a high magnetic permeability core arranged inside the case and surrounding the distribution line, and a change in magnetic flux collected by the core. And a magnetic flux detecting means for detecting
A distribution line monitoring device, wherein the shortest distance between the core and the outer surface of the case is equal to or more than the shortest distance between the core and the distribution line. 2. A case composed of two parts, an upper part and a lower part, for sandwiching and fixing a distribution line, and a voltage divider for dividing the stray capacitance between the distribution line and the ground into a capacitor by at least one of the two cases. A voltage detecting means for detecting a voltage divided by the voltage divider, a high magnetic permeability core that circulates around a distribution line, and a magnetic flux detecting means for detecting a change in magnetic flux collected by the core, The distribution line monitoring device is arranged such that the shortest distance between the core and the voltage divider is not less than the distance between the conductors of the voltage divider. 3. A case composed of two parts, an upper part and a lower part, for sandwiching and fixing a distribution line, and a voltage divider for dividing the stray capacitance between the distribution line and the ground into a capacitor by at least one of the two cases. A voltage detecting means for detecting the voltage divided by the voltage divider, a high-permeability core that circulates around the distribution line, a magnetic flux detecting means for detecting a change in the magnetic flux collected by the core, and the voltage divider. And a conductor installed in the case body on the side of storing the capacitor, the outer conductor of the capacitor voltage divider is connected to the conductor installed in the case body on the side of storing the voltage divider, and the core and the voltage divider The distribution line monitoring device is arranged such that both the shortest distance and the shortest distance between the core and the conductor installed in the case body are equal to or greater than the distance between conductors of the voltage divider. 4. The core is divided in the vicinity of a boundary between an upper case body and a lower case body that house the voltage divider, and the divided cores are connected via an insulator. The distribution line monitoring device according to 1, 2, or 3.