JP2023149404A - Rogowskii coil - Google Patents

Abstract

To provide a Rogowskii coil which removes the necessity of a return line without using an electrostatic shield member and can reduce the cost since the coil can be easily manufactured.SOLUTION: The present invention includes: a coil 120 arranged to surround a conductor 20 in which a measurement target current I flows; a coating member 121; a first outlet line 120c connected to a beginning end part 120a of the coil 120; a first connection member 123b connected to a terminal end part 120b of the coil 120; a second connection member 122a electrically and mechanically connected to the first connection member 123b by a connector connection; and a second connection line 120d connected to the second connection member 122a. A current which is flowing in the coil 120 according to a measurement target current I is measured by a measurement circuit 16 by the first output line 120c and the second output line 120d in an output cable 124.SELECTED DRAWING: Figure 1

Description

The present invention relates to a Rogowski coil that is installed, for example, in a tower of a wind power generation facility or a tower leg of a power transmission tower to measure the magnitude of lightning surge current and the number of lightning strikes during lightning strikes.

Conventionally, as this type of Rogowski coil, the one described in Patent Document 1, for example, is known.
FIG. 5 shows the Rogowski coil described in Patent Document 1. In FIG. 5, 10 is the Rogowski coil body, 11 is the winding core, 12 is the coil wound along the circumferential direction of the winding core 11, 13 is the return wire of the coil 12, 14 and 15 are the output wires, and 16 is the detection wire. A measuring circuit for amplifying and integrating signals, 17 a display section for displaying measurement results, and 18 an electrostatic shielding member surrounding the inner and outer circumferential surfaces of the Rogowski coil body 10.

As is well known, the Rogowski coil is installed so as to surround the conductor 20 through which the current to be measured I flows, and the magnetic flux generated by the current to be measured I interlinks with the coil 12 to generate an induced electromotive force. The magnitude of the current to be measured I is measured by detecting the current flowing due to this induced electromotive force.
For example, when measuring lightning surge current caused by lightning striking a blade or tower of wind power generation equipment, or a power transmission tower, the Rogowski coil body 10 is installed so as to surround the tower leg of the tower or power transmission tower. In order to process the output wires 14 and 15 together at one end of the Rogowski coil main body 10, the terminal end of the coil 12 is returned to the vicinity of the start end by the return wire 13 and the output wires 14 and 15 are drawn out. ing.

However, the work of passing the return wire 13 through the center of the coil 12 and leading it to the starting end side is extremely complicated, prolongs the manufacturing time, and requires a great deal of labor.
For this reason, for example, in Patent Document 2, as shown in Rogowski coil body 10A in FIG. 6, the terminal end of the coil 12 is connected to an electrostatic shield member 18, and this electrostatic shield member 18 is used as an equivalent return line. By using this, the return line 13 in FIG. 5 is made unnecessary.

Patent No. 5547031 (Figure 1, etc.) JP 2011-174769 (Figure 1, etc.)

However, in the Rogowski coil described in Patent Document 2, the electrostatic shielding member 18 is essential, and if the electrostatic shielding member 18 is not provided, the structure shown in FIG. 6 cannot be adopted.
Additionally, the larger the base of the tower or power transmission tower to be installed, the longer the length of the Rogowski coil in the circumferential direction. , which led to high costs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a Rogowski coil that does not require an electrostatic shielding member or the like, eliminates the need for a return line, and can be easily manufactured to reduce costs.

In order to solve the above problems, the Rogowski coil of the present invention includes: a coil disposed to surround a conductor through which a current to be measured flows; a covering member covering the coil; A first output line connected to the starting end of the coil, a first connecting member connected to the terminal end of the coil, and a second connecting member mechanically and electrically connected to the first connecting member by connector coupling. , and a second output line connected to the second connection member, the current flowing through the coil in accordance with the current to be measured can be measured by a measurement circuit via the first output line and the second output line. It is.

Moreover, as described in claim 2, the reinforcing conductor arranged on the peripheral wall of a hollow hose through which gas, liquid, or powder flows is the coil, and the peripheral wall is connected to the covering member. It is desirable to use it as a.

According to the present invention, it is possible to eliminate the need for a return line without using an electrostatic shielding member or the like. In addition, if a reinforcing conductor provided on the peripheral wall of a hollow hose through which gas, liquid, or powder flows is used as a coil, and the peripheral wall is used as a covering member, manufacturing is easy and low-cost. Rogowski coils can be provided.

1 is an overall configuration diagram showing an embodiment of the present invention. FIG. 3 is a partial cross-sectional view of a Rogowski coil body in an embodiment of the present invention. FIG. 3 is an enlarged explanatory diagram of a connector portion in an embodiment of the present invention. 2 is a circuit diagram showing an example of the measurement circuit shown in FIG. 1. FIG. FIG. 1 is a configuration diagram of a Rogowski coil showing a prior art. FIG. 2 is a configuration diagram of a Rogowski coil showing another conventional technique.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an overall configuration diagram of the Rogowski coil according to this embodiment.
In FIG. 1, reference numeral 100 is a Rogowski coil body whose both ends can be connected with connectors. This Rogowski coil body 100 has a current detection coil 120 housed inside a covering member 121, and has flexibility as a whole so that it can surround the conductor 20 through which the current I to be measured flows. The conductor 20 is, for example, a grounding wire built into a tower of a wind power generation facility or a tower leg of a power transmission tower, and the current to be measured I is a lightning surge current flowing through the conductor 20.

Connectors 122 and 123 are provided at both ends of the Rogowski coil body 100, respectively. These connectors 122 and 123 are used to mechanically and electrically connect a first connecting portion 123b and a second connecting portion 122a, which will be described later, with the Rogowski coil body 100 installed so as to surround the conductor 20. belongs to.
Further, on the connector 122 side, an output cable 124 is provided that accommodates output lines 120c and 120d, which will be described later, which are connected to the starting end and the ending end of the coil 120, respectively. and display section 17 are connected in sequence.

FIG. 2 is a partial cross-sectional view of the Rogowski coil body 100. As the Rogowski coil body 100, a hollow hose through which gas, liquid, or powder flows can be used. A conductor (such as a steel wire) can be used as the coil 120.

FIG. 3 shows an enlarged view of the connector portion of the Rogowski coil body 100.
Inside one connector 122, a starting end (winding start) 120a of the coil 120 is connected to a first output line 120c. Further, a second connection portion 122a connected to a second output line 120d is arranged inside the connector 122, and the first output line 120c and the second output line 120d are connected to the measurement circuit by an output cable 124. 16.
Furthermore, inside the other connector 123, a first connection part 123b connected to the terminal end (winding end part) 120b of the coil 120 is arranged, and by joining the connectors 122 and 123, both the connection parts 122a , 123b are configured to be mechanically and electrically connected.

In FIG. 3, the shapes and structures of the connectors 122, 123, the first connecting portion 123b, and the second connecting portion 122a are shown conceptually and in principle in a simplified manner, and their specific shapes and structures are shown in the illustrated example. It is not limited in any way. For example, the connecting portions 122a and 123b may have a connection structure other than the male type and female type illustrated.
That is, the connectors 122, 123 and the connecting parts 122a, 123b may have any shape as long as they can electrically connect the connecting parts 122a, 123b by mechanically coupling both ends of the Rogowski coil body 100. , may be a structure.

Next, FIG. 4 is a circuit diagram showing an example of the measurement circuit 16.
In FIG. 4, output lines 120c and 120d of the output cable 124 described above are connected to the input terminal IN. The resistor R ₁ and the capacitor C ₁ function as a low-pass filter (integrator), and for example, pass a signal (current signal) of 0.1 to 300 [kHz] within a range of ±3 [dB] from the reference gain. . The resistor _R1 is configured as a variable resistor so that the gain of the output signal of this low-pass filter becomes a predetermined value depending on the length of the signal cable 124 and the outer diameter of the coil 120.

The connection point between the resistor R ₁ and _the capacitor C ₁ is connected to the inverting input terminal of the first operational amplifier OP 1, and the non-inverting input terminal of this operational amplifier OP ₁ is grounded. Furthermore, a series circuit of resistors R ₂ and R ₄ and a parallel circuit of a capacitor C ₂ are connected to the feedback circuit of the operational amplifier OP ₁ , and the connection point between the resistors R ₂ and R ₄ is grounded via a resistor R ₃ . has been done.
The operational amplifier OP ₁ , which has resistors R ₂ , R ₃ , R ₄ and a capacitor C ₂ in its feedback circuit, integrates a signal input through a low-pass filter (integrator) and outputs a voltage of a predetermined magnitude. It works like this.

Further, the connection point between the resistor _R4 and the capacitor _C2 is connected to the inverting input terminal of the second operational amplifier _OP2 via the resistor _R5 , and the non-inverting input terminal of this operational amplifier _OP2 is grounded. Further, a resistor _R6 is connected to the feedback circuit of the operational amplifier _OP2 , and a voltage amplified according to the ratio of the resistors _R5 and _R6 is sent from the output terminal OUT to the display section 17 in FIG. The magnitude of lightning surge current is displayed along with the time of lightning strike and the number of lightning strikes. Note that in FIG. 4, illustration of the positive and negative power supplies of the operational amplifiers OP ₁ and OP ₂ is omitted.
The signal obtained from the output terminal OUT may be transmitted to the outside and centrally monitored.

The gist of the present invention is to remove the return wire of the coil 120 from the Rogowski coil body 100 and to connect both ends of the Rogowski coil body 100 with a connector, etc., and the configuration of the measurement circuit 16 is as follows. Of course, the present invention is not limited to what is shown in FIG. 4.

16: Measurement circuit 17: Display section 20: Conductor 100: Rogowski coil body 120: Coil 120a: Starting end 120b: Terminating end 120c: First output line 120d: Second output line 121: Covering member 122, 123: Connector 122a : Second connection member 123b: First connection member 124: Signal cable I: Current to be measured IN: Input terminal OUT: Output terminal OP ₁ , OP ₂ : Operational amplifier R ₁ to R6: Resistor C ₁ , C ₂ : Capacitor

Claims (2)

a coil arranged to surround a conductor through which a current to be measured flows;
a covering member that covers the coil;
a first output line connected to the starting end of the coil;
a first connecting member to which a terminal end of the coil is connected;
a second connecting member mechanically and electrically connected to the first connecting member by connector coupling;
a second output line connected to the second connection member;
Equipped with
A Rogowski coil, characterized in that a current flowing through the coil in accordance with the current to be measured can be measured by a measuring circuit via the first output line and the second output line. The Rogowski coil according to claim 1,
A Rogowski coil, characterized in that the coil is a reinforcing conductor placed on a peripheral wall of a hollow hose through which gas, liquid, or powder flows, and the peripheral wall is used as the covering member.

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