JP3765780B2 - Electromagnetic field sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric field magnetic field sensor used for non-contact measurement of a transmission voltage and a transmission current phenomenon of a transmission / distribution electric wire line or a substation facility which is an outdoor power facility.
[0002]
[Prior art]
Transformers, resistance voltage dividers, capacitor voltage dividers, insulator voltage dividers, optical PTs, electric field detectors, etc. are used for voltage measurement during power transmission or failure of power facilities, and current transformers, Z Type CT, Hall CT, optical CT, magnetic field detector, etc. are used.
[0003]
Transformers, resistance voltage dividers, capacitor voltage dividers, and insulator voltage dividers used for voltage measurement must be designed in consideration of withstand voltage because they are directly connected to the power line. Although there is a characteristic with respect to the frequency, there is no frequency characteristic with respect to a high-frequency voltage caused by a voltage phenomenon at the time of failure, for example, a phenomenon such as a lightning failure. The optical PT has characteristics from a commercial frequency to a high frequency, but is difficult to install because it needs to pass a power line. The electric field detector obtains characteristics from commercial frequency to high frequency without contact with the power equipment, but the detection output tends to fluctuate due to the influence of rain.
[0004]
A current transformer used for current measurement needs to be connected to a power line and does not have high-frequency characteristics. The Z-type CT needs to pass a power line, needs to be grounded in consideration of withstand voltage, and does not have good high frequency characteristics. The hall CT has frequency characteristics but needs to be in contact with the underground line. The optical CT also needs to be attached to the power line although it has frequency characteristics. The magnetic field detector has no frequency contact with the power line and good frequency characteristics.
[0005]
A system that has been used in a conventional overhead power transmission line to measure a transmission voltage and a transmission current phenomenon in a contactless manner will be described (for example, see Patent Document 1).
Fig. 1 is a schematic diagram of an overhead transmission line. In the figure, 1 is a power station on the supply side (transmission equipment), 2 is a neutral point resistor of a transformer, 3 is a three-phase overhead transmission line, and 4 is electricity on the demand side. It is a place. FIG. 2 is a conceptual diagram showing a state in which an electric field magnetic field sensor is arranged on a power transmission tower. In FIG. 2, 5 is a steel tower, 3a, 3b, 3c of the overhead power transmission line 3 shown in FIG. 1, 6a, 6b, 6c are These are electric field magnetic field sensors, and these sensors are opposed to the transmission lines 3a, 3b, and 3c in a non-contact manner. Hereinafter, the power transmission lines 3a, 3b, and 3c and the electric field magnetic field sensors 6a, 6b, and 6c are simply referred to as the power transmission line 3 and the electric field magnetic field sensor 6 except that they are specifically shown.
[0006]
FIG. 3 is a conceptual diagram showing a state in which an electric field magnetic field sensor is arranged on a gantry of a substation equipment, and reference numeral 7 in the figure receives the gantry of the power transmission equipment or electricity for transmitting electricity to the overhead power transmission line 3 shown in FIG. It is a stand for the power receiving facility of the demand side electric station 4, and in any case, the electric field magnetic field sensor 6 faces the power transmission line 3 in a non-contact manner as in FIG. 2.
[0007]
FIG. 4 is a conceptual diagram simply showing the configuration of a conventional electric field magnetic field sensor 6. In the figure, 10 is an electric field electrode for detecting voltage, 11 is an insulating pipe for fixing the electric field electrode, 12 is a magnetic field coil for detecting current, 13 is a connection box, and coaxial cable 14 (for example, 1.5D2V2). A cable containing the book and the electric field electrode 10 and the lead wire of the magnetic field coil 12) are wired. In the figure, 15 is a connector of the cable 14, and 16 is a mounting screw for installing the electric field magnetic field sensor 6 on the steel tower 5 or the gantry 7. This conventional electric field magnetic field sensor 6 has a frequency characteristic from a commercial frequency to a high frequency without contact with the transmission line 3.
[0008]
[Patent Document 1]
Japanese Examined Patent Publication No. 6-70665 [0009]
[Problems to be solved by the invention]
By the way, the conventional electric field magnetic field sensor 6 shown in FIG. 4 does not need to install two sensors in a limited place in terms of cost as compared with the case where the electric field sensor and the magnetic field sensor are separately provided. It is possible to measure voltage and current with a single sensor, which is directly proportional to the transmission voltage value and current value, and inversely proportional to the distance between the power line 3 and the electric field magnetic field sensor 6, but detected by the electric field electrode 10 The electric field value is likely to change under the influence of rain.
[0010]
This phenomenon is a major drawback that affects the performance of voltage measurement. The cause is that rainwater collects in the insulating pipe 11 and the junction box 13, and when the rainwater is in contact with the steel tower 5 or the gantry 7 which is the attachment member of the electric field magnetic field sensor 6, the weak current detected by the electric field electrode 10 is a water film. It is diverted to the ground through and becomes less sensitive. On the other hand, when rainwater collects in the insulating pipe 11 and the junction box 13 and contacts the electric field electrode 10 through the water film and does not contact the steel tower 5 or the gantry 7, the water film from rainwater also becomes the electric field electrode. This is because the sensitivity is increased by increasing the area. Due to the above two causes, the detected electric field value increases or decreases when it rains compared to when it is not raining.
However, for current measurement, since the insulating pipe 11 that fixes the magnetic field coil 12 passes the magnetic flux with resin, the frequency characteristics are good.
[0011]
In view of the above-mentioned conventional problems, the present invention can measure voltage and current with a single sensor without contact with a power transmission / distribution line, etc., and the measured voltage value is not affected by rainwater. An object of the present invention is to provide a supplementary electric field magnetic field sensor.
[0012]
[Means for Solving the Problems]
In order to achieve the above object , the electric field magnetic field sensor of the present invention is an electric field magnetic field sensor for non-contact measurement of a transmission voltage and a transmission current phenomenon of a transmission / distribution line or a substation, and includes an electric field detection unit and a magnetic field detection. And a connecting part for attaching the detecting part to the attaching part such as a steel tower, and a connecting member for connecting the detecting part and the connecting part apart from each other. In addition to covering with a cap, the bottom of the detection unit is formed in a concave shape to cover the upper end side of the connecting member .
[0013]
In order to achieve the above object, in the electric field magnetic field sensor having the above configuration, at least one wire-like conductor is exposed on the outer peripheral surface of the cap, and the conductor is connected to the electric field detection unit. It is characterized by becoming.
[0014]
In order to achieve the above object, in the electric field magnetic field sensor configured as described above, the outer wall of the detection unit is formed as an electric field detection unit, and the outer wall member is provided with a cut portion along the vertical direction. .
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In the following description, common parts are denoted by common reference numerals, and redundant description is omitted.
FIG. 5 is a conceptual diagram showing a configuration of an embodiment of an electric field magnetic field sensor according to the present invention, FIG. 6 is a conceptual diagram showing a state in which an electric field magnetic field sensor is arranged in a vertical direction on a power transmission tower, and FIG. A sectional view, FIG. 8 is a plan view of the cap, and FIG. 9 is a sectional view showing the configuration of the electric field magnetic field sensor in which the mounting direction of the magnetic field detection coil is changed.
In the figure, 20 is an electric field electrode, 21 is a magnetic field coil, 22 is a resin cap, 23 is a stainless steel pipe, 24 is a connection box, 25 is a coaxial cable, 26 is a cable connector, and 27 is a mounting screw.
Then, as shown in FIG. 5, the electric field electrode 20 as the electric field detection unit and the magnetic field coil 21 as the magnetic field detection unit are integrated into a cylindrical detection unit, and the electric field electrode 20 is the outer periphery of the cylindrical part of the detection unit. While being provided on the surface (outer wall member), the magnetic field coil 21 is mounted inside the detection unit.
[0016]
As shown in FIGS. 5 and 7, the electric field magnetic field sensor 6 of the present embodiment has a substantially cylindrical metal pole 20 made of, for example, a stainless steel pipe and cut vertically, for example, at one place so as not to shield magnetic flux. (The cut portion is indicated by reference numeral 20a). The stainless steel pipe 20d constituting the electric field electrode 20 is fixed to a resin bracket 20b through which magnetic flux passes. The bottom 20c of the bracket 20b is formed in a concave shape so that the stainless steel pipe 23, which is a connecting member to the connection box 24, is not wetted by rainwater.
Specifically, the magnetic field coil 21 is mounted inside the middle of the cylindrical case 20e, brackets 20b and 20f are fixed to the upper and lower ends, and a gap having a predetermined width in the vertical direction on the outer periphery of the cylindrical case 20e (cutting portion 20a). A stainless steel pipe 20d (electric field electrode 20) is provided. A part of the cylindrical case 20e is penetrated, and an electric wire is connected to the stainless steel pipe 20d at the position of the cut portion 20a and fixed with a molding material. The upper end of the stainless pipe 23 having a smaller diameter than that of the bracket 20 b is fixed to the center of the concave bottom of the bracket 20 b at the lower end, and the lower end of the stainless pipe 23 is fixed to the connection box 24.
[0017]
The magnetic field detection coil 21 is configured by winding the electric wire 21b several hundred times around the bobbin 21a in consideration of the frequency characteristic from commercial frequency to high frequency and the magnitude of the coil output voltage.
In the relationship between the power line 3 and the electric field magnetic field sensor 6, the mounting direction of the magnetic field detection coil 21 is as shown in FIG. 5 or 9, and the electric field magnetic field sensor 6 is mounted in an upright state.
[0018]
As shown in FIGS. 5 and 8, the cap 22 covering the top of the electric field electrode 20 (detection unit) is made of a conical resin so as not to shield magnetic flux and to easily allow rainwater to fall. . Further, in order to prevent the electric field detection state from changing even when wet with rainwater, for example, a stainless steel wire 22a is sewed to be exposed on the outer surface. Specifically, a plurality of exposed portions of the wire 22a are radially arranged on the inclined surface of the cap 22, and both end portions of the exposed wire 22a are connected to the back surface side through the inclined surface of the cap 22 and the like. The wire 22a exposed on the cap 22 is connected to the stainless steel pipe 20d provided on the outer peripheral surface of the detection unit in a cylindrical case 20e below the cap 22, and the other wire 22a of the stainless steel pipe 20d is also formed as a part of the electric field electrode 20. is doing. Of course, the shape of the cap 22 may be a pyramid or the like if rainwater can easily flow down.
[0019]
As shown in FIG. 5, the electric field electrode 20 (stainless steel pipe 20d and wire 22a) and the electric wire for flowing the signal of the magnetic field detection coil 21 are accommodated in the stainless steel pipe 23 which fixes the detection part and the connection box 24, and the stainless steel pipe As the outer covering material 23, a material that repels rainwater, for example, a shrinkable tube made of Teflon (registered trademark) is attached and protected.
[0020]
According to the above-described structure, the wire 22a provided on the cap 22 becomes a part of the electric field electrode 20, and even when rain water adheres to the cap 22 or the like and a water film is generated, it is exposed on the surface of the cap 22. Since the wire 22a is more conductive than the water film and has the effect of concentrating the electric field normally, the electric field electrode 20 becomes the stainless steel pipe 20d and the wire 22a regardless of rain water. The strength does not change.
Even if the detection unit or the connection box 24 gets wet with rainwater, the bottom of the detection unit (the bottom 20c of the bracket 20b) is concave, so that the outer peripheral surface (stainless steel pipe 20d) of the detection unit and the stainless steel pipe 23 of the connecting member. Since they are not contacted and separated from each other, the weak electric current of the detected electric field does not leak to the tower 5 or the gantry 7.
Therefore, even when it is raining, the power transmission voltage phenomenon is detected without being affected by rainwater as in the case of non-rainfall.
Further, the stainless steel pipe 20d provided with the electric field electrode 20 on the outer peripheral surface of the detection unit is provided with a cut portion 20a in the vertical direction and opens a part of the stainless steel pipe 20d, so that the magnetic flux due to the current of the power line 3 is shielded. Without being detected by the magnetic field detection coil 21.
[0021]
In the example of FIG. 5, if the coil 21 for detecting current is housed in the connection box 24 and the electric field detection unit and the magnetic field detection unit are separated, the distance between the transmission line and the electric field electrode 20 and the magnetic field coil 21 Since the angles are different, it is impossible to correctly obtain the zero-phase voltage and the zero-phase current obtained by adding the sensor outputs.
[0022]
【The invention's effect】
As described above, the electric field magnetic field sensor according to the present invention can measure the voltage and current with a single sensor without contact with a transmission line, etc., and is advantageous not only in terms of cost and installation space, or even not change the electric field detected intensity detection unit is wet with rain, because weak current of the detected electric field does not leak to the tower or the like, the transmission voltage phenomenon can stably detected without being affected by the rain water, also claim In 2 or 3, the magnetic field can be measured without shielding the magnetic flux.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of an overhead power transmission line showing a system of power equipment.
FIG. 2 is a conceptual diagram showing a state where an electric field magnetic field sensor is arranged on a power transmission tower.
FIG. 3 is a conceptual diagram showing a state in which an electric field magnetic field sensor is arranged on a gantry of a substation facility.
FIG. 4 is a conceptual diagram simply showing the configuration of a conventional electric field magnetic field sensor.
FIG. 5 is a cross-sectional view showing a configuration of an embodiment of an electric field magnetic field sensor according to the present invention.
FIG. 6 is a conceptual diagram showing a state where electric field magnetic field sensors are arranged in the vertical direction on a power transmission tower.
7 is a cross-sectional view taken along the line AA in FIG.
FIG. 8 is a plan view of the cap.
FIG. 9 is a cross-sectional view showing the configuration of an electric field magnetic field sensor in which the mounting direction of the magnetic field detection coil is changed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electricity station 2 Supply side Neutral resistor 3 Transformer overhead transmission line 4 Electric power station 5 Demand side power transmission tower 6, 6a, 6b, 6c Electric field magnetic field sensor 7 Power transmission or transformation equipment base 10 Field pole 11 Insulated pipe 12 Magnetic coil 13 Junction box 14 Coaxial cable 15 Cable connector 16 Mounting screw 20 Field pole 20a Pipe cutting section 20b forming the field pole Pipe bracket 20c forming the field pole Recessed bottom 20d of the bracket Field pole Stainless steel pipe 20e Cylindrical case 20f Bracket 21 Magnetic coil 21a Bobbin 21b Electric wire 22 Plastic cap 22a Wire 23 Stainless steel pipe 24 Connection box 25 Coaxial cable 26 Cable connector 27 Mounting screw

Claims (3)

An electric field magnetic field sensor for non-contact measurement of transmission voltage and transmission current phenomenon of transmission / distribution lines and substation equipment, and it is attached to a detection part that integrates an electric field detection part and a magnetic field detection part, and a mounting location such as a steel tower And a connecting member that separates and connects the detection unit and the connection unit. The top of the detection unit is covered with a conical cap, and the bottom of the detection unit is formed in a concave shape. In the electric field magnetic field sensor covering the upper end side of the connecting member ,
An electric field magnetic field sensor comprising: a wire-like conductor exposed on at least one of the outer peripheral surfaces of the cap; and the conductor is connected to the electric field detection unit. Electric field magnetic field sensor for non-contact measurement of transmission voltage and transmission current phenomenon of transmission / distribution electric lines and substation equipment, and is attached to a detection part that integrates an electric field detection part and a magnetic field detection part, and a mounting location such as a steel tower And a connecting member that separates and connects the detection unit and the connection unit, the top of the detection unit is covered with a cone-shaped cap, and the bottom of the detection unit is formed in a concave shape In the electric field magnetic field sensor covering the upper end side of the connecting member,
An electric field magnetic field sensor characterized in that an outer wall of the detection unit is formed as an electric field detection unit, and a cut portion is provided on the outer wall member along the vertical direction. 2. The electric field magnetic field sensor according to claim 1, wherein an outer wall of the detection unit is formed as an electric field detection unit, and a cut portion is provided in the outer wall member along the vertical direction.

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