WO2014103298A1

WO2014103298A1 - Reactor

Info

Publication number: WO2014103298A1
Application number: PCT/JP2013/007580
Authority: WO
Inventors: 智彰田宮; 正志澤田
Original assignee: 川崎重工業株式会社
Priority date: 2012-12-27
Filing date: 2013-12-25
Publication date: 2014-07-03
Also published as: JP6055306B2; JP2014127610A

Abstract

　This reactor (1) is equipped with: a magnetic core (2) having a gap (5); a winding (3) wrapped around the core (2) in a coil shape; and a plate-shaped cooling member (4) which is arranged between the winding (3) and a part of the core (2) that includes a gap (5), and the inside of which is provided with a flow path (9) for coolant.

Description

Reactor

The present invention relates to a reactor cooling structure having a winding wound in a coil shape around a magnetic core having a gap.

The reactor has a gap in the core to adjust the inductance. In a reactor having a structure in which the gap is located inside the winding, the leakage magnetic flux in the gap is linked to the neighboring winding, and an eddy current is generated in the winding. For this reason, it is known that the winding near the gap has a large copper loss and causes local heat generation. Winding heat can shorten the life of the equipment due to deterioration and, in some cases, cause serious accidents due to burning. Therefore, in the design of the reactor, it is required to efficiently cool the winding near the gap.

Conventional reactors often use air cooling or forced air cooling as a cooling method. However, in the reactor, the cooling between the core and the windings is hindered by an insulating material or a supporting material for windings, and it is difficult to efficiently cool the windings in the vicinity of the gap, which is a problem in air cooling or forced air cooling. For this reason, there is often a problem that a design having a sufficient space in the structure is adopted, resulting in a large product. Moreover, since a cooling fan (forced air cooling only) and a vent are required, there is a problem that noise and an increase in the size of the control panel are caused.

Also, as another cooling method, there is a structure in which a flow path is provided inside the winding to circulate the refrigerant. However, this method has a problem that the cost increases because the basic structure is different from the conventional one due to the use of special windings.

Recently, a water-cooled reactor has been proposed that has high heat dissipation efficiency and a basic structure that is almost the same as a conventional one (see, for example, Patent Document 1). In the conventional water-cooled reactor, only the heat radiating plate is inserted between the core and the winding, and heat exchange with the refrigerant pipe is performed at the end of the heat radiating plate.

Japanese Patent Laid-Open No. 11-288819

However, since the conventional water-cooled reactor performs heat exchange with the refrigerant pipe at the end of the heat sink inserted between the core and the winding, a certain distance is provided between the refrigerant pipe and the heat generating part. Occurs, and the area of the path to the end of the heat radiating plate that performs heat exchange is reduced. For this reason, there existed a subject that thermal resistance was large and the temperature gradient inside a heat sink became large.

This invention was made in order to solve the above problems, and it aims at providing the reactor which can suppress a temperature rise efficiently.

In order to solve the above problems, a reactor according to an aspect of the present invention includes a magnetic core having a gap, a winding wound around the core in a coil shape, and a portion of the core including the gap. A plate-like cooling member disposed between the windings and provided with a coolant channel therein.

With the above-described configuration, the plate-like cooling member (heat sink) in which the refrigerant flow path is provided directly cools the windings in the vicinity of the gap where the temperature rise is large, so that the reactor can be efficiently cooled. Furthermore, by selecting the flow path and flow rate of the refrigerant, it is possible to achieve an optimal heat dissipation design that reduces heat generation and increases heat dissipation, so that the reactor can be downsized.

The refrigerant flow path may be formed along the gap of the core. With the above configuration, a temperature rise near the gap can be more efficiently suppressed.

The cooling member may be a plate-like member having nonmagnetic properties and thermal conductivity.

With the above configuration, since the plate-like cooling member has nonmagnetic and thermal conductivity, a shielding effect against the leakage magnetic flux in the gap can be obtained, and the temperature rise of the winding can be suppressed. For example, copper or aluminum may be used as the non-magnetic and thermally conductive member.

An insulator may be further provided between the winding and the cooling member.

With the above configuration, since the insulation between the winding and the cooling member is reinforced, even when a high voltage is applied to the reactor, between the cooling member and the winding, which is a conductor, The possibility of a short circuit occurring can be suppressed.

The cooling member may be arranged so that both ends in the circumferential direction of the core do not contact each other.

With the above configuration, it is possible to prevent the circulating current from flowing through the cooling member induced by the magnetic flux passing through the core.

According to the present invention, it is possible to provide a reactor capable of efficiently suppressing a temperature rise.

The above object, other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.

FIG. 1 is a perspective view of a reactor according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the reactor of FIG. 1 along the line AA ′. 3 is a cross-sectional view of the reactor of FIG. 1 taken along the line BB ′. FIG. 4 is an exploded perspective view of a cooling member provided in the reactor of FIG. FIG. 5 is an enlarged partial cross-sectional view of the vicinity of the gap of the reactor of FIG. FIG. 6 is a first cross-sectional view of the reactor according to the second embodiment of the present invention. FIG. 7 is a second cross-sectional view of the reactor according to the second embodiment of the present invention. FIG. 8 is a cross-sectional view of a reactor according to a modification of the second embodiment of the present invention.

Embodiments of the present invention will be described with reference to the drawings. Below, the same code | symbol is attached | subjected to the element which is the same or it corresponds through all the drawings, and the overlapping description is abbreviate | omitted.

(Embodiment 1)
FIG. 1 is a perspective view of a reactor 1 according to Embodiment 1 of the present invention. As shown in FIG. 1, a reactor 1 includes a magnetic core 2, a winding 3 wound around the core 2 in a coil shape, and a plate-like cooling member 4 disposed between the core 2 and the winding 3. And comprising. Use of reactor 1 according to the present embodiment is not particularly limited. The reactor 1 is used for an input / output filter of an inverter, for example. In addition, the core 2 and the coil | winding 3 which comprise the reactor 1 do not need to use the member of a special specification, and can use a well-known thing.

FIG. 2 is a cross-sectional view taken along line AA ′ of reactor 1 in FIG. As shown in FIG. 2, the core 2 of the iron core that is a magnetic body has a gap 5. The core 2 penetrates the inside of the coiled winding 3. In the present embodiment, four gaps 5 are formed in the core 2. Then, the winding 3 is disposed in a portion including the gap 5 of the core 2, and the plate-like cooling member 4 provided with a flow path 9 between the portion including the gap 5 of the core 2 and the winding 3. Is arranged.

FIG. 3 is a cross-sectional view of the reactor of FIG. 1 taken along the line BB ′. As shown in FIG. 3, the cooling member 4 provided with the flow path 9 is disposed around the core 2 constituting the magnetic circuit, and the winding 3 is disposed outside thereof. Needless to say, the wires (electric wires) constituting the winding 3 are themselves covered with an insulating layer. In the present embodiment, four cooling members 4 are arranged in four directions around the core 2. Here, the cooling member 4 is disposed so that both ends in the circumferential direction of the core 2 do not contact each other. That is, the four cooling members 4 need to be arranged so that at least the ends in the circumferential direction of the core 2 do not contact each other. This is to prevent the circulating current from flowing through the cooling member 4 induced by the magnetic flux passing through the core 2. Here, the four cooling members are arranged so that both ends in the circumferential direction of the core 2 do not contact the adjacent cooling members 4.

FIG. 4 is an exploded perspective view of the cooling member 4 provided in the reactor 1. As shown in FIG. 4, the cooling member 4 is provided with a refrigerant flow path 9 therein. In the present embodiment, the cooling member 4 is configured by a plate-shaped water-cooled heat sink. The cooling member 4 has a three-layer structure in which three plate-like members are overlapped. Specifically, the cooling member 4 includes a flat plate 6, a plate 7 in which a groove (flow path) 9 through which a refrigerant passes, and a supply port 10 including through holes formed in upper and lower corners on one side. And a flat plate 8 having a discharge port 11.

The plates 6 to 8 are plate-like members having nonmagnetic and thermal conductivity. In the present embodiment, copper is used as a member having nonmagnetic properties and thermal conductivity.

The groove (flow path) 9 of the plate 7 is formed so as to meander in the plate plane of the cooling member 4 in the lateral direction along the gap 5 of the core 2 so that the refrigerant passes through the flow path. Yes. In the present embodiment, coolant that is liquid (for example, antifreeze) is used as the refrigerant passing through the flow path 9.

The refrigerant in the cooling member 4 is supplied from an external pump unit (not shown) to the cooling member 4 through the supply port 10, and after exchanging heat in the cooling member 4, the refrigerant is drained from the discharge port 11 to be pump unit. Return to. Thus, the refrigerant circulates through the flow path 9 in the cooling member 4. In addition, this pump unit may be used in common with other water cooling units, for example, a cooling unit for cooling the IGBT used in the inverter.

Next, the operation and effect of the reactor 1 having the above configuration will be described.

FIG. 5 is an enlarged partial sectional view of the vicinity of the gap 5 of the reactor 1 in FIG. Arrows indicate magnetic flux. As shown in FIG. 5, in the vicinity of the gap 5 of the core 2, a leakage magnetic flux (arrow in the figure) is generated outside the gap 5. As a result, an eddy current is generated in the winding 3. When the loss due to the eddy current in the winding 3 increases, the efficiency of the reactor decreases and the temperature of the winding 3 during operation becomes high.

Therefore, in the present embodiment, the coil 3 in the vicinity of the gap 5 having a large temperature rise is directly cooled by the plate-like cooling member 4 in which the refrigerant flow path 9 is provided. Thereby, the core 2 and the coil | winding 3 can be cooled efficiently simultaneously, and by extension, the reactor 1 can be cooled efficiently.

Also, since the plate-like cooling member 4 has non-magnetic and thermal conductivity, a shielding effect against the leakage magnetic flux in the gap can be obtained, and the temperature rise of the winding can be suppressed.

Furthermore, by selecting the flow path and flow rate of the refrigerant, it is possible to design an optimum heat dissipation that reduces heat generation and increases heat dissipation. Thereby, size reduction of a reactor is realizable. Further, since the cooling fan (forced air cooling) and the vent are not required, low noise and space saving can be realized.

In addition, since the cooling member (water-cooled heat sink) 4 in each direction is a conductor, when these are integrated, there is a concern about an increase in loss due to eddy current and a deterioration in the characteristics of the reactor 1. Therefore, in the present embodiment, the cooling member 4 (water-cooled heat sink) is arranged in four directions around the core 2 but is not integrated. That is, the four cooling members 4 as a whole are arranged so that both ends in the circumferential direction of the core 2 are not in contact with each other, and both ends in the circumferential direction of the core 2 are in contact with the adjacent cooling members 4. Arranged not to. Thereby, it is possible to prevent the circulating current from flowing to the cooling member due to the magnetic flux of the core.

When integrating the cooling member 4 (water-cooled heat sink), the heat sinks may be integrated after being insulated.

Next, the effect of this embodiment will be described in comparison with a conventional example.

In the conventional reactor, a heat sink is inserted between the core and the winding, and heat exchange is performed with the refrigerant pipe connected to the end of the heat sink. The conventional reactor is common to the present embodiment in that the liquid is used as the refrigerant and the refrigerant is circulated.

However, in the conventional example, a distance is generated between the refrigerant pipe and the core that is the heat generating portion, and the area of the path to the end of the heat radiating plate that performs heat exchange is reduced. For this reason, a thermal resistance is large and the temperature gradient inside a heat sink will become large.

On the other hand, in the present embodiment, as shown in FIG. 2, the cooling member 4 in which the refrigerant flow path 9 is provided is inserted between the core 2 and the winding 3, and the cooling member 4 generates heat. It is provided in the vicinity of the core gap 5 which is a portion. Thereby, since the coil | winding of the vicinity with a large temperature rise can be directly cooled, suppressing the change of a reactor as much as possible, a cooling capability can be improved compared with a prior art example.

In the conventional example, since a heat sink is used, if the coil and the heat sink, and the heat sink and the refrigerant pipe are not in close contact with each other, the cooling capacity is greatly reduced. On the other hand, since the heat radiation plate and the refrigerant pipe of the conventional example are integrated as the cooling member 4 in this embodiment, the coil and the cooling member 4 can be brought into close contact with each other, and a sufficient cooling effect is obtained. be able to. Since there is no significant change in the structure with respect to the conventional reactor, an increase in new production costs can be suppressed.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the following, description of the points common to the first embodiment will be omitted, and different points will be mainly described. 6 and 7 are cross-sectional views of the reactor 1 according to Embodiment 2 of the present invention. The reactor 1 of the second embodiment is different from the reactor 1 of the first embodiment in that it further includes an insulating member 12 disposed between the winding 3 and the cooling member 4. The insulating member 12 only needs to be an insulator having an insulating property against a high voltage. In the present embodiment, for example, an aramid fiber sheet is used.

Since the plate constituting the cooling member 4 of the reactor 1 is a conductor, there is a possibility that a short circuit occurs between the plate and the winding at a high voltage. Therefore, in the present embodiment, in addition to the effect of the first embodiment, the insulation between the winding 3 and the cooling member 4 is reinforced, so that a high voltage is applied to the reactor 1. In addition, the possibility of a short circuit occurring between the cooling member 4 and the winding 3 that are conductors can be suppressed.

In the present embodiment, the use of a very thin member for the insulating member 12 can minimize the influence on heat conduction.

[Modification]
Moreover, although the reactor 1 of Embodiment 2 of this invention was set as the structure which arrange | positions the insulating member 12 between the coil | winding 3 and the cooling member 4, as shown in the modification of FIG. May be inserted between the core 2 and the cooling member 4. Since the core 2 is usually a conductor, in the configuration of the second embodiment, there is a possibility that a loop-like flow path in which a circulating current flows undesirably by the core 2 and the cooling member 4 may be formed. Therefore, by disposing the insulating member 12, such a state can be avoided.

In this modification as well, as in the second embodiment, the use of a very thin member for the insulating member 12 can minimize the influence on heat conduction.

In each of the embodiments described above, the core 2 of the iron core, which is a magnetic material, includes four gaps 5, but the present invention is not limited to this. According to the present embodiment, since the winding can be directly cooled by the cooling member, there can be enough room for the temperature rise around one gap, and therefore the number of gaps 5 can be further reduced. Thus, for example, there may be two gaps. Thereby, the processing cost of a core gap can be held down.

In each of the above embodiments, copper is used as a member having nonmagnetic properties and thermal conductivity. However, other materials such as aluminum may be used.

In each of the above embodiments, the groove (flow path) 9 of the plate 7 is formed so as to meander in the plate plane of the cooling member 4 along the gap of the core. It is not limited to a simple configuration. The plate 7 only needs to have a flow path formed so that the plate 7 is cooled substantially uniformly by the refrigerant. For example, the plate 7 may be formed to meander in the vertical direction, or may include a plurality of flow paths.

In each of the above embodiments, the flow path through which the refrigerant flows is formed by sandwiching one plate with grooves between two plates, but is not limited to such a configuration. For example, a refrigerant pipe may be arranged inside the plate.

In each of the above-described embodiments, the cooling member 4 is installed on the four sides of the core 2 (cross-sectional view is square), but if it is between the portion including the gap 5 of the core 2 and the winding 3, for example, The core 2 may be installed on one side, two sides, or three sides.

In each of the above embodiments, the coolant flowing in the flow path of the cooling member is liquid cooling water (for example, antifreeze liquid). However, the present invention is not limited to this, and the coolant is a mixture of liquid and gas. There may be.

From the above description, many modifications and other embodiments of the present invention are apparent to persons skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

The present invention can be used for a reactor that performs a cooling system (for example, a water cooling system) using a liquid or a mixture of liquid and gas as a refrigerant.

1 Reactor 2 Core 3 Winding 4 Cooling member 5 Gap 6 Plate 7 Grooved plate 8 Plate with mouth 9 Groove (flow path)
10 Supply port 11 Discharge port 12 Insulating member

Claims

A magnetic core having a gap;
Windings coiled around the core;
A reactor comprising: a plate-like cooling member disposed between a portion including the gap of the core and the winding, and having a refrigerant flow path provided therein.
The reactor according to claim 1, wherein the flow path of the refrigerant is formed along a gap of the core.
The reactor according to claim 1 or 2, wherein the cooling member is a plate-like member having nonmagnetic properties and thermal conductivity.
The reactor according to any one of claims 1 to 3, further comprising an insulator disposed between the winding and the cooling member.
The reactor according to any one of claims 1 to 4, wherein the cooling member is disposed so that both ends in the circumferential direction of the core do not contact each other.