Logoski coil

Abstract

This invention provides a Rogowski coil that eliminates the need for return wires by not using electrostatic shielding materials, and is easy to manufacture, thereby reducing costs. [Solution] The Rogowski coil according to the present invention comprises a Rogowski coil body 100 using a hollow hose through which a flexible gas, liquid, or powder flows, a pair of connectors provided at both ends of the Rogowski coil body 100 and mechanically joined to each other, a first output wire, and a second output wire. The Rogowski coil body 100 comprises a coil 120 made of a reinforcing conductor that reinforces the peripheral wall portion of the hollow hose, a starting end of the reinforcing conductor at one end of both ends, and a terminating end of the reinforcing conductor at the other end of both ends. The reinforcing conductor is housed inside a covering member 121 made of synthetic resin or rubber that constitutes the peripheral wall portion.

Description

Technical Field

[0001] This invention relates to a Rogowski coil installed, for example, on the tower of a wind power generation facility or the tower base of a transmission tower to measure the magnitude of lightning surge current and the number of lightning strikes during a lightning strike.

Background Art

[0002] Conventionally, as this type of Rogowski coil, for example, the one described in Patent Document 1 is known. FIG. 5 shows the Rogowski coil described in Patent Document 1. In FIG. 5, 10 is the Rogowski coil main body, 11 is the bobbin, 12 is the coil wound along the circumferential direction of the bobbin 11, 13 is the return wire of the coil 12, 14 and 15 are output wires, 16 is a measurement circuit that performs amplification, integration, etc. of the detection signal, 17 is a display unit that displays the measurement result, and 18 is an electrostatic shielding member that surrounds the inner and outer peripheral surfaces of the Rogowski coil main body 10.

[0003] As is well known, the Rogowski coil is installed so as to surround the conductor 20 through which the measured current I flows. The magnetic flux generated by the measured current I intersects the coil 12 to generate an induced electromotive force, and the current flowing due to this induced electromotive force is detected to measure the magnitude of the measured current I and the like. For example, when measuring the lightning surge current generated by a lightning strike on the blade or tower of a wind power generation facility or a transmission tower, it is necessary to install the Rogowski coil main body 10 so as to surround the tower or the tower base of the transmission tower. In order to collectively process the output wires 14 and 15 on one end side of the Rogowski coil main body 10, the end portion 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.

[0004] However, the operation of passing the return wire 13 through the center of the coil 12 and routing it to the start end side is extremely complicated, the manufacturing time is prolonged, and a great deal of labor is required. For this reason, as shown in Patent Document 2, for example, the Rogowski coil body 10A in Figure 6, the 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, thereby eliminating the need for the return line 13 in Figure 5. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 5547031 [Patent Document 2] Japanese Patent Publication No. 2011-174769 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, in the Rogowski coil described in Patent Document 2, the electrostatic shielding member 18 is indispensable, and if the electrostatic shielding member 18 is not provided, the structure shown in Figure 6 cannot be adopted. Furthermore, as the tower base of the tower or transmission tower on which the coil is installed increases, the circumferential length of the Rogowski coil increases. This requires considerable effort and time to wind the coil 12 along the winding core 11, which leads to higher costs.

[0007] Therefore, the problem that this invention aims to solve is to provide a Rogowski coil that eliminates the need for a return wire without using electrostatic shielding members, and that can be easily manufactured, thereby reducing costs. [Means for solving the problem]

[0008] To solve the above problems, the Rogowski coil of the present invention is as described in claim 1, A Rogowski coil body using a hollow hose through which a flexible gas, liquid, or powder flows, A pair of connectors are provided at both ends of the Rogowski coil body and are mechanically joined to each other, First output line and, Second output line and, Equipped with, The Rogowski coil body comprises a coil made of a reinforcing conductor that reinforces the peripheral wall portion of the hollow hose, a starting end of the reinforcing conductor at one end of the two ends, and a terminal end of the reinforcing conductor at the other end of the two ends, The reinforcing conductor is housed inside the covering member made of synthetic resin or rubber that constitutes the peripheral wall portion. The pair of connectors comprises a start-end connector provided at one end, a terminal-end connector provided at the other end, a first connecting member disposed inside the terminal-end connector, and a second connecting member disposed inside the start-end connector. The aforementioned starting end is connected to the first output line, The first connecting member is connected to the terminal portion, The second connecting member is connected to the second output line, The Rogowski coil body is configured to be positioned so as to surround another conductor through which the current to be measured flows, by mechanically and electrically connecting the first connecting member and the second connecting member. The current flowing through the coil in accordance with the current to be measured can be measured by the measurement circuit via the first output line and the second output line.

[0009] Furthermore, as described in claim 2, it is preferable that the reinforcing conductor is a steel wire. Furthermore, as described in claim 3, it is preferable that the covering member not include a return wire that returns the end portion to the vicinity of the start portion. [Effects of the Invention]

[0010] According to the present invention, a return wire can be made unnecessary without using an electrostatic shielding member or the like. Further, by using a reinforcing conductor provided on the peripheral wall portion of a hollow hose through which a gas, a liquid, or a powder flows as a coil and using the peripheral wall portion as a covering member, a Rogowski coil that is easy to manufacture and low in cost can be provided.

Brief Description of the Drawings

[0011] [Figure 1] It is an overall configuration diagram showing an embodiment of the present invention. [Figure 2] It is a partial cross-sectional view of a Rogowski coil main body in an embodiment of the present invention. [Figure 3] It is an enlarged explanatory view of a connector portion in an embodiment of the present invention. [Figure 4] It is a circuit diagram showing an example of the measurement circuit shown in FIG. 1. [Figure 5] It is a configuration diagram of a Rogowski coil showing the prior art. [Figure 6] It is a configuration diagram of a Rogowski coil showing another prior art.

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a Rogowski coil according to this embodiment. In FIG. 1, reference numeral 100 denotes a Rogowski coil main body whose both ends can be connected by a connector. The Rogowski coil main body 100 has a flexible whole so that a coil 120 for current detection is accommodated inside a covering member 121 and can surround a conductor 20 through which a measured current I flows. The conductor 20 is, for example, a ground wire built in a tower of a wind power generation facility or a tower leg portion of a transmission tower, and the measured current I is a lightning surge current flowing through the conductor 20.

[0013] Connectors 122 and 123 are provided at both ends of the logosky coil body 100 respectively. These connectors 122 and 123 are for mechanically and electrically connecting the first connection part 123b and the second connection part 122a, which will be described later, when the logosky coil body 100 is installed so as to surround the conductor 20. Also, on the connector 122 side, an output cable 124 for accommodating output lines 120c and 120d, which will be described later and are respectively connected to the start end and the end of the coil 120, is provided. The measurement circuit 16 and the display unit 17 are sequentially connected to this output cable 124.

[0014] Figure 2 is a partial cross-sectional view of the logosky coil body 100. As this logosky coil body 100, a hollow hose through which gas, liquid or powder flows can be used. A peripheral wall portion made of synthetic resin or rubber, etc. is used as the covering member 121, and a reinforcing conductor (such as a steel wire) wound around its inner surface can be used as the coil 120.

[0015] Figure 3 shows an enlarged view of the connector part of the logosky coil body 100. Inside one of the connectors 122, the start end (winding start part) 120a of the coil 120 is connected to the first output line 120c. Also, inside the connector 122, a second connection part 122a connected to the second output line 120d is arranged. The first output line 120c and the second output line 120d are connected to the measurement circuit 16 by the output cable 124. Furthermore, inside the other connector 123, a first connection part 123b connected to the end (winding end) 120b of the coil 120 is arranged. By coupling the connectors 122 and 123, the two connection parts 122a and 123b are configured to be mechanically and electrically connected.

[0016] In Figure 3, the shapes and structures of connectors 122, 123, the first connection part 123b, and the second connection part 122a are shown in a conceptual and principled manner, and their specific shapes and structures are not limited in any way to the illustrated examples. For example, the connection parts 122a and 123b may have connection structures other than the male-to-female type shown in the illustration. In other words, the connectors 122, 123 and the connecting parts 122a, 123b can have any shape or structure as long as they can electrically connect to each other by mechanically joining both ends of the Rogowski coil body 100.

[0017] Next, Figure 4 is a circuit diagram showing an example of the measurement circuit 16. In Figure 4, the output lines 120c and 120d of the aforementioned output cable 124 are connected to the input terminal IN. The resistor R1 and capacitor C1 function as a low-pass filter (integrator), allowing signals (current signals) in the range of 0.1 to 300 kHz to pass through within a range of ±3 dB from a 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 according to the length of the signal cable 124 and the outer diameter of the coil 120.

[0018] The connection point between resistor R1 and capacitor C1 is connected to the inverting input terminal of the first operational amplifier OP1, and the non-inverting input terminal of this operational amplifier OP1 is grounded. In addition, a series circuit of resistors R2 and R4 and a parallel circuit of capacitor C2 are connected to the feedback circuit of operational amplifier OP1, and the connection point between resistors R2 and R4 is grounded via resistor R3. The operational amplifier OP1, which has resistors R2, R3, R4 and capacitor C2 in its feedback circuit, operates to integrate the input signal via a low-pass filter (integrator) and output a voltage of a predetermined magnitude.

[0019] Furthermore, the connection point between resistor R4 and capacitor C2 is connected to the inverting input terminal of the second operational amplifier OP2 via resistor R5, and the non-inverting input terminal of this operational amplifier OP2 is grounded. In addition, resistor R6 is connected to the feedback circuit of operational amplifier OP2, and the amplified voltage according to the ratio of resistors R5 and R6 is sent from the output terminal OUT to the display unit 17 in Figure 1, and the magnitude of the lightning surge current is displayed along with the time and number of lightning strikes. Note that the positive and negative power supplies of operational amplifiers OP1 and OP2 are not shown in Figure 4. The signal obtained from the output terminal OUT may be transmitted externally for centralized monitoring.

[0020] The gist of this 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, and of course the configuration of the measurement circuit 16 is not limited in any way to what is shown in Figure 4. [Explanation of symbols]

[0021] 16: Measurement circuit 17: Display section 20: Conductor 100: Logoski coil body 120: Coil 120a: Starting point 120b: Termination part 120c: 1st output line 120d: Second output line 121: Covering member 122,123: Connectors 122a: Second connecting member 123b: First connecting member 124: Signal cable I: Current to be measured IN: Input terminal OUT: Output terminal OP1, OP2: Operational amplifiers R1~R6: Resistance C1, C2: Capacitors

Claims

1. A Rogowski coil body using a hollow hose through which a flexible gas, liquid, or powder flows, A pair of connectors are provided at both ends of the Rogowski coil body and are mechanically joined to each other, First output line and, Second output line and, Equipped with, The Rogowski coil body comprises a coil made of a reinforcing conductor that reinforces the peripheral wall portion of the hollow hose, a starting end of the reinforcing conductor at one end of the two ends, and a terminal end of the reinforcing conductor at the other end of the two ends, The reinforcing conductor is housed inside the covering member made of synthetic resin or rubber that constitutes the peripheral wall portion. The pair of connectors comprises a start-end connector provided at one end, a terminal-end connector provided at the other end, a first connecting member disposed inside the terminal-end connector, and a second connecting member disposed inside the start-end connector. The aforementioned starting end is connected to the first output line, The first connecting member is connected to the terminal portion, The second connecting member is connected to the second output line, The first connecting member and the second connecting member are mechanically and electrically connected, allowing the Rogowski coil body to be positioned to surround another conductor through which the current to be measured flows. A Rogowski coil characterized in that 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.

2. In the Rogowski coil described in claim 1, The Rogowski coil is characterized in that the reinforcing conductor is a steel wire.

3. In the Rogowski coil described in claim 1 or claim 2, A Rogowski coil characterized in that the covering member does not have a return wire inside that returns the terminal portion to the vicinity of the starting portion.

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