JP2014199835A - Inductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inductor capable of preventing heat generation due to eddy current.SOLUTION: An inductor has a core assembly 1 and a fixing tool 3. The core assembly 1 has a gap g in a part of a magnetic path. The fixing tool 3 is attached to a position P2 not linked with a magnetic leakage flux generated in the gap g.

Description

  The present invention relates to an inductor, and more particularly, to an inductor used as a railway reactor or an impedance bond.

  Conventionally, inductors of various structures have been proposed and used in practical use. For example, the invention described in Patent Document 1 is a DC reactor installed on the return side of a DC substation for electric railways, and includes a coil and a core assembly inserted into the coil. The core assembly is a so-called gapd iron core, in which a plurality of iron core blocks made of a ferromagnetic material and a plurality of paramagnetic blocks interposed between the iron core blocks are alternately stacked to form a metal fixture. It has the cylindrical structure integrated by.

  By the way, it is known that this type of inductor is affected by leakage magnetic flux from the gap portion, and an eddy current is generated in the fixture to cause a problem of heat generation. In particular, when this type of inductor is a railway reactor, the railway reactor is used under a large current and a high voltage, and therefore, prevention of heat generation due to the generation of eddy current is required to a higher degree.

  In this regard, conventional railroad reactors employ an oil cooling system that cools heat generated by eddy currents by filling oil in a housing that houses the reactor.

  However, there are cases where the above-described oil cooling method cannot always be employed in railway facilities. For example, a railway reactor installed in a tunnel has a problem that an oil cooling method cannot be adopted from the viewpoint of fire prevention.

  No means for solving the above-described problem is disclosed in Patent Document 1.

JP 2009-177012 A

  The subject of this invention is providing the inductor which can prevent the heat_generation | fever by an eddy current.

  In order to solve the above-described problems, an inductor according to the present invention includes a core assembly and a fixture. The core assembly has a gap in a part of the magnetic path, and the fixture is attached at a position not interlinked with the leakage magnetic flux generated in the gap. According to this structure, since the fixture is attached at a position not interlinked with the leakage magnetic flux generated in the gap of the core assembly, the influence of the leakage magnetic flux on the fixture is avoided, thereby preventing the heat generation due to the eddy current. be able to.

  As described above, according to the present invention, an inductor capable of preventing heat generation due to eddy current can be provided.

  Other objects, configurations and advantages of the present invention will be described in more detail with reference to the accompanying drawings. The accompanying drawings are merely examples.

It is front sectional drawing of the inductor which concerns on embodiment of this invention. It is side surface sectional drawing of the inductor shown in FIG. FIG. 2 is a plan view showing an internal structure of the inductor shown in FIG. 1. FIG. 4 is a front view of the core assembly shown in FIGS. 1 to 3. FIG. 5 is a plan view of the coil shown in FIGS. 1 to 4. FIG. 4 is a perspective view of the core assembly of the inductor shown in FIGS. 1 to 3. FIG. 7 is a side view of the core assembly shown in FIG. 6.

  1 to 7, the same reference numerals indicate the same or corresponding parts. TECHNICAL FIELD The present invention relates to an inductor, and more specifically, to a railway return line reactor that is connected to an electric railway substation and sucks up a train current by being installed on the return line side, and an inductor used as an impedance bond for a railway. . The inductor of FIGS. 1 to 3 includes a core assembly 1 for high current and high magnetic flux density, and a coil 2. Since these are well-known components in the technical field, they will be briefly described below.

  The core assembly 1 is formed by combining at least two core portions into a cylindrical shape when viewed from the front, and has a gap (g) in a part of the magnetic path. Specifically, the core assembly 1 shown in FIGS. 1 to 3 is a so-called wound core, and includes a first core portion 11, a second core portion 12, a third core portion 13, and a fourth core. Part 14.

  Each of the first to fourth core portions 11 to 14 is a so-called iron core block, which is obtained by winding a magnetic metal plate a plurality of times, hardening it with resin, cutting it, and polishing it. The first and second core parts 11 and 12 have a U-shape when viewed from the front, and the both ends of the U-shape of the second core part 12 face the both ends of the first core part 11. Is arranged in. The third core portion 13 is disposed between one end of the first core portion 11 and one end of the second core portion 12, and the fourth core portion 14 is the other end of the first core portion 11 and the second core portion. 12 is arranged between the other end. That is, the core assembly 1 includes a pair of first and second core portions 11 and 12 and third and fourth core portions 13 and 14 that connect upper and lower ends of the first and second core portions 11 and 12. And has an integrated cylindrical structure by being fastened by a band-like fastening tool 15.

  The core assembly 1 has a gap g on both sides in the width direction w when viewed from the front. That is, the core assembly 1 is an iron core with a gap that forms an annularly connected magnetic path, and the gap g is between the first core portion 11 and the third core portion 13, and the first core portion 11. And the fourth core portion 14, between the second core portion 12 and the third core portion 13, and between the second core portion 12 and the fourth core portion 14.

  The coil 2 (see FIG. 5) is wound at a position overlapping the gap g on both side portions in the width direction w of the core assembly 1. The gap g is disposed within the height dimension of the coil 2.

  By the way, this type of inductor is affected by the leakage magnetic flux from the gap (g) portion, and eddy currents are generated in the fixture (eddy current loss) to generate heat and coil resistance (copper loss). It is known to generate heat in the coil (2). In particular, when this type of inductor is a railroad reactor, the railroad reactor is used under a large current and a high voltage, so that the prevention of heat generation due to eddy current loss and copper loss is more advanced. Is required.

  In this regard, conventional rail reactors employ an oil cooling system that cools heat generated by eddy current loss and copper loss by filling oil in a housing that houses the reactor.

  However, there are cases where the above-described oil cooling method cannot always be employed in railway facilities. For example, a railway reactor installed in a tunnel has a problem that an oil cooling method cannot be adopted from the viewpoint of fire prevention. In addition, the oil cooling method has a problem that the quality of the oil is rapidly deteriorated and the maintenance cost is high because the oil must be replaced frequently.

  One of the features of the inductor according to the present invention is to solve the above-mentioned problem, to reduce the influence of leakage magnetic flux on the fixture, and thus to prevent the eddy current loss (and heat generation). It is in the point which devised the aspect and the coupling | bonding aspect. The inductor shown in FIGS. 1 to 3 includes a fixture 3, a housing case 4, and a heat dissipating resin (not shown) for cooling.

  The fixture 3 is attached to a position P2 (see FIG. 4) that does not interlink with the leakage magnetic flux generated in the gap g. Both ends of the fixture 3 viewed in the axial direction a are bent along the both end faces 10 of the core assembly 1 and attached along the axial direction a on the outer periphery of the core assembly 1, whereby the core assembly 1. Is tightened in the height direction h intersecting the width direction w. The fixture 3 is fixed at both end sides across the outer peripheral direction (a).

  Here, the fixture 3 is fixed to a position P2 that is magnetically and physically spaced from the position P1 of the gap g (see FIG. 4). If the position P2 of the fixture 3 is separated from the position P1 by 5 times or more with reference to the gap g, an eddy current due to leakage magnetic flux does not occur. For example, when the gap g is 1 cm, generation of eddy current can be avoided by separating the gap g by 5 times or more. If the number of gaps g is increased and the gap per gap g is narrowed, the distance to be separated is reduced, so that heat generation can be avoided and the size can be reduced.

  The fixture 3 is coupled to the inside of the storage housing 4 in a state where the core assembly 1 is stored in the storage housing 4. Specifically, the core assembly 1 shown in FIGS. 1 to 3 is fixed to the bottom of the housing 4 with one stat bolt 6 on each side. With this configuration, the fixture 3 receives the fastening force F1 of the stat bolt 6 as viewed in the height direction h and the fastening force F1 with respect to the core assembly 1 in the housing 4 and the fixture 3 itself bends. Tightening force F2 in the front-rear direction (axial direction a) generated by this, and tightening force F3 (slip due to frictional force) generated when the fixture 3 is brought into close contact with the core assembly 1 by receiving the tightening force F1. The core assembly 1 is fixed in the housing 4 by applying a fixing force in three directions (see FIGS. 6 and 7).

  The heat dissipating resin (not shown) is filled in the internal space of the housing 4, and the core assembly 1 is covered with the heat dissipating resin.

  The inductor described with reference to FIGS. 1 to 7 can solve all the conventional problems described above. That is, the core assembly 1 has a gap g in a part of the magnetic path, and the fixture 3 is attached to a position P2 that does not interlink with the leakage magnetic flux generated in the gap g. According to this structure, the influence of the leakage magnetic flux on the fixture 3 can be reduced, and eddy current loss can be prevented.

  Moreover, since the fixing tool 3 provides the tightening forces F1 to F3, it is possible to prevent vibration and beat (magnetostriction) of the core assembly 1. Further, since the fixture 3 is directly fixed to the bottom of the housing 4 by one stat bolt 6 at the front and rear, the number of parts for fixing is small and the working efficiency is improved.

  Since the inductor adopts a resin cooling method in which the housing case 4 is filled with a heat-dissipating resin, heat generated in the coil 2 due to copper loss can be radiated and cooled. Thus, since the inductor is an oil-less resin cooling method, unlike the oil cooling method, there is no problem of quality degradation. Therefore, the maintenance cost can be reduced.

  However, the resin cooling method tends to have a lower heat dissipation efficiency than the conventional oil cooling method. In this regard, in the inductors shown in FIGS. 1 to 7, eddy current loss (and heat generation) is prevented by the arrangement of the fixture 3. In other words, in the inductors shown in FIGS. 1 to 7, it is only necessary to cool the heat generated by the copper loss, so that it is possible to adopt a resin cooling method using a heat-dissipating resin and the amount of heat-dissipating resin filled. Even if it is reduced, a sufficient cooling effect is realized.

  Although the contents of the present invention have been specifically described above with reference to the preferred embodiments, it is obvious that those skilled in the art can take various modifications based on the basic technical idea and teachings of the present invention. It is.

DESCRIPTION OF SYMBOLS 1 Core assembly 10 Both ends of core assembly 3 Fixing tool 4 Storage housing g Gap a Axial direction w Width direction h Height direction

Claims (6)

An inductor having a core assembly and a fixture,
The core assembly has a gap in a part of the magnetic path;
The fixture is attached at a position not interlinked with the leakage magnetic flux generated in the gap.
Inductor. An inductor according to claim 1,
The core assembly is cylindrical and has the gap on both sides in the width direction when viewed from the front.
The fixing device is attached along the axial direction on the outer periphery of the core assembly, and clamps the core assembly in a height direction intersecting the width direction.
Inductor. An inductor according to claim 2, wherein
Both ends of the fixing device viewed in the axial direction are bent along both end surfaces of the core assembly.
Inductor. The inductor according to any one of claims 1 to 3, further comprising a housing case,
The core assembly is housed in the housing;
The fixing device is coupled to the inside of the storage casing in a state where the core assembly is stored in the storage casing.
Inductor. The inductor according to claim 4, wherein the housing is filled with resin.
Inductor.   The inductor according to any one of claims 1 to 5, wherein the inductor is used as a reactor or an impedance bond.

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