JPH04118667U - Rogowski coil - Google Patents

Abstract

(57) [Summary] [Purpose] The present invention relates to a Rogowski coil used for measuring surge-prone current in a current probe that measures current without contact. Another object is to be able to easily measure current regardless of measurement conditions. [Structure] A flexible tube that has hardness with little deformation in the cross-sectional direction and flexibility in the longitudinal direction, and has a spiral groove on its surface, and an insulated core wire is attached to the flexible tube along the groove. It is characterized by comprising a coil formed by winding it, and a return line in which the terminal end of the insulated core wire forming the coil is passed through a flexible tube and folded back.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a current probe that measures current without contact. This article relates to Rogowski coils, which are commonly used.

0002

[Conventional technology]

To measure impulse voltage or current, steady-state DC or AC voltages and This requires a different approach than measuring current. Conventionally, accidents such as lightning surge current For general current measurement, there are two methods: measuring the polarity and peak current value using a piece of magnetic steel, and using a coaxial system. How to measure voltage and convert it to current value using a shunt resistor, loop antenna A method of measuring electromagnetic field changes and estimating current values using electromagnetic induction in Rogowski coils. A method of determining the current value by measuring the conducted voltage and other methods are used.

0003 Among them, the Rogowski coil measurement method requires changing the shape of the object to be measured. Since there is no need for communication cables or power cables, and current measurement is possible without contact. , or as a method of measuring lightning surge current flowing through structures such as pillars and beams of buildings. It is the most commonly used. FIG. 3 is a diagram showing the basic configuration of the Rogowski coil.

0004 In the figure, the Rogowski coil has an insulated core wire attached to an annular coil support 51. The coil 52 is wound at various pitches and the wire at the end is folded through the center of the coil 52. It has a return line 53 that has been turned back, and the core wire at the beginning of winding and the core wire that has been turned back are drawn close to each other. It is configured to be released. Reference numeral 54 indicates an object to be measured, and its cross section is shown. This measured When a current flows in the longitudinal direction of the fixed object 54 and the current passing through the ring changes, the coil 5 Since a voltage is induced in 2, the system is to integrate this voltage over time and obtain the measured current. It has become. Note that the integrator and other components are omitted in the figure.

[0005]

[Problem that the idea aims to solve] By the way, the Rogowski coil is used to stabilize its shape and improve sensitivity. In some cases, iron, ferrite, or other magnetic materials are used as the core material of the coil support. An electrostatic shield using iron, copper, aluminum, or other metal pipes is installed around the outside of the cell. It is often done.

[0006] Therefore, in conventional Rogowski coils, their size and shape are This was determined at the time of manufacture and could not be changed at the time of measurement. Sunawa Therefore, in order to handle many types of objects with different sizes and shapes, it is necessary to Manufacture and prepare a large number of Rogowski coils according to each size and shape. There was a need.

[0007] Also, if you need to set it through a gap, the Rogowski coil itself can be It was not flexible and lacked workability and flexibility. Therefore, the pillars and beams of a building It is not suitable for measuring current flowing through walls or walls, and there are few devices suitable for that purpose. It was. This invention can be used to measure objects of various sizes and shapes, and depends on the measurement conditions. We offer a highly versatile Rogowski coil that allows you to easily perform current measurements without The purpose is to provide

[0008]

[Means to solve the problem]

The Rogowski coil according to claim 1 has hardness with little deformation in the cross-sectional direction. It is flexible in the longitudinal direction and has spiral grooves on its surface. A flexible tube and an insulated core wire are wound around the flexible tube along the groove. The coil formed by attaching the coil and the terminal end of the insulated core wire forming the coil to the frame. It is characterized by having a return line that passes through the flexible tube and turns back.

[0009] The invention according to claim 2 is the Rogowski coil according to claim 1, in which: Contains a braided conductor or other flexible sleeve to provide electrostatic shielding around the perimeter. Features.

0010

[Effect]

The device according to claim 1 uses a flexible tube as a support. By forming an air-core coil, a rotor with a large diameter and excellent workability and flexibility can be created. Gosky coil can be realized. Therefore, the size and shape of the object to be measured The installation work can be carried out efficiently according to the measurement conditions.

[0011] Additionally, we create a spiral groove in the flexible tube and form a coil along it. This prevents the coil from shifting during deformation during installation of the Rogowski coil. Changes in linear density can be avoided. The invention according to claim 2 also includes a braided conductor in the electrostatic shield body of the Rogowski coil. Maintain the flexibility of the Rogowski coil by using other flexible sleeves. It is possible to provide electrostatic shielding while also providing electrostatic shielding.

0012

【Example】

FIG. 1 is a diagram showing an embodiment of the invention according to claim 1. In the figure, an air-core coil is formed using a flexible tube 11 as a support. . The flexible tube 11 has hardness with little deformation in the cross-sectional direction. It is flexible in the longitudinal direction and has a spiral groove 12 on its surface. Sunawa In other words, the material is not easily crushed as a tube and can be easily bent into an annular shape. use something For example, vinyl chloride, polyethylene and other hard or soft plastic pipes are used. In addition, inside this flexible tube 11 Flexibility is maintained by coating or laminating the walls with a thin magnetic material. Sensitivity can be increased while maintaining

[0013] The coil 13 is made by winding an insulated core wire around the flexible tube 11 along the groove 12. It's huge. The terminal end of this coil 13 is passed through the flexible tube 11. It is then turned back to form a return line 14, forming a Rogowski coil. In addition, The coil 13 is an insulated core wire with plastic or enamel insulation, and has a groove. Even if the flexible tube 11 is bent by being wrapped along the It is designed to prevent misalignment. In other words, it is possible to maintain a uniform pitch. It is possible to obtain stable characteristics even after repeated Rogowski coil installation work. It has a possible structure.

[0014] As shown in FIG. 1, the Rogowski coil of the present invention has a flexible tube 11 Since it is flexible and a part of it is open, the flap is not needed when measuring current. Pass the object to be measured through the open end of the flexible tube 11 while bending it. It is easy to set it in the center. Note that the current flowing through the measured object causes the The voltage induced in the coil 13 is taken out by an integrator or other current measuring means (not shown). The measured current can then be determined.

[0015] FIG. 2 is a diagram showing an embodiment of the device according to claim 2, and (a) is a schematic plan view thereof. Schematic diagram, (b) shows a sectional view taken along line A-A. In the figure, the flexible tube 11, coil 13 and return line shown in FIG. 14 is given the same reference numeral and will not be described. Although the groove 12 cannot be shown in the figure, It is provided in a spiral shape on the surface of the flexible tube 11.

[0016] The features of the present invention include the flexible tube 11, coil 13 and Copper wires are knitted in a mesh pattern around the outer circumference of the Rogowski coil constituted by the return line 14. By covering the conductor with a soldered braided conductor 21, an electrostatic shield is realized and performance deterioration due to electrostatic induction is suppressed. It has a structure that controls it. In addition, in order to realize electrostatic shielding, the braided conductor 21 must be used. Instead of a flexible sleeve, thread copper or acuminium tape or other metal tape. It may be wound spirally.

[0017]

[Effect of the idea]

As explained above, the invention according to claim 1 can be used as a support for a Rogowski coil. Since a flexible tube is used, it is possible to measure objects with slightly different shapes. However, it is versatile enough to be handled with just one Rogowski coil. In addition, a logo is placed on the object to be measured. When setting the ski coil, it can be deformed so it can be passed through gaps. It is easy and can realize high workability and flexibility. Furthermore, the coil The structure is such that the coil is fixed with a groove, so the pitch of the coil will change even if used repeatedly. Stable measurements can be performed without any problems.

[0018] The invention according to claim 2 provides electrostatic shielding using a flexible sleeve. In addition to the above-mentioned effects, it is possible to realize a highly accurate Rogowski coil. Ru. In addition, the Rogowski coil of this invention has a simple structure, so it can be manufactured easily and inexpensively. can be made.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the device according to claim 1.

FIG. 2 is a diagram showing an embodiment of the invention according to claim 2.

FIG. 3 is a diagram showing the principle configuration of a Rogowski coil.

[Explanation of symbols]

11 Flexible tube 12 Groove 13 Coil 14 Return route 21 Braided conductor 51 Coil support 52 coil 53 Return route 54 Object to be measured

──────────────────────────────────────────────── ─── Continuation of front page (72) Creator Koji Takemoto 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Within Hon Telegraph and Telephone Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. A flexible tube that has hardness with little deformation in the cross-sectional direction and flexibility in the longitudinal direction, and has a spiral groove on its surface, and an insulated core wire is disposed along the groove. A Rogowski coil comprising: a coil formed by winding it around the flexible tube; and a return line in which a terminal end of an insulated core wire forming the coil is passed through the flexible tube and folded back. 2. The Rogowski coil according to claim 1, further comprising a flexible sleeve such as a braided conductor that covers the outer periphery of the Rogowski coil for electrostatic shielding.