JP2011096916A - Capacitor and power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitor capable of preventing an increase in the temperature of a capacitor element formed near a heat-generating body and preventing deterioration in the service life of the capacitor element. <P>SOLUTION: A plurality of capacitor elements 3 each having a pair of electrode surfaces 35 at both ends are accommodated in an accommodating case 2 so that the electrode surfaces 35 can face the same direction. Connecting portions 4a, 4b for connecting the plurality of capacitor elements 3 in parallel are disposed in pairs on the electrode surfaces 35. Of the plurality of capacitor elements 3, a capacitor element 30 closest to the heat-generating body 5 other than the capacitor elements 3 is a high-resistance capacitor element 30 having higher electric resistance between the electrode surfaces 35 than that of the other capacitor elements 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a capacitor having a plurality of capacitor elements and a power conversion device using the capacitor.

  Conventionally, a capacitor for use in a power converter or the like is known (see Patent Document 1 below). 15 and 16 are an exploded perspective view and a cross-sectional view of a conventional capacitor 90. FIG. As shown in the figure, the capacitor 90 is obtained by storing a plurality of capacitor elements 91 in a storage case 92 and sealing the capacitor elements 91 with a resin 95. Each capacitor element 91 has a pair of electrode surfaces 96 at both ends, and metal bus bars 93 and 94 are connected to the electrode surfaces 96. A plurality of capacitor elements 91 are connected in parallel by bus bars 93 and 94.

  As shown in FIGS. 15 and 16, the bus bars 93 and 94 include connection terminals 93a and 94a for connecting to other electronic components. The connection terminals 93 a and 94 a stand from the bus bars 93 and 94 toward the opening 97 of the storage case 92 and protrude from the surface of the resin 95.

On the other hand, as shown in FIG. 16, a heating element such as a reactor 99 is disposed in the vicinity of the capacitor 90. The reactor 99, the capacitor 90, a semiconductor module (not shown) and the like constitute the power converter.
When the power converter is used, a current flows through each capacitor element 91 of the capacitor 90, and the temperature of each capacitor element 91 rises due to resistance heat.

Japanese Patent No. 3864938

However, when the conventional capacitor 90 is used, resistance heat is also generated in the connection terminal 94a due to the current flowing therethrough, and the capacitor element 91a adjacent to the connection terminal 94a is connected to the connection terminal 94a. There is also a problem that the temperature tends to rise. The lifetime of the capacitor element 91 is shortened when the temperature during use becomes too high. For this reason, among the plurality of capacitor elements 91, the life of the capacitor element 91a adjacent to the connection terminal 94a tends to be particularly short.
Therefore, the conventional capacitor 90 has a problem that the life of the capacitor 90 as a whole is likely to be shortened due to some of the capacitor elements 91a even though the other capacitor elements 91 are normal. In order to prevent this, the conventional capacitor 1 has to be mounted with an extra capacitor element so that the life of the capacitor element 91a is exhausted and can operate normally as a whole even after a failure.

  Further, as shown in FIG. 16, the capacitor element 91b adjacent to the reactor 99 also receives the heat generated from the reactor 99, the temperature rises, and the life is likely to be shortened.

Further, when the capacitor 90 is mounted on a vehicle, there is a problem that only a part of the capacitor elements 91 are heated due to heat generated from the engine of the vehicle, and the life is shortened.
Therefore, there is a demand for a capacitor that can suppress an increase in temperature of a capacitor element existing near a heating element such as an engine, a reactor, or the connection terminal, and can prevent a decrease in the life of the capacitor element.

  The present invention has been made in view of such conventional problems, and includes a capacitor capable of suppressing a temperature rise of a capacitor element existing near a heating element and preventing a decrease in lifetime of the capacitor element, and the capacitor. An object of the present invention is to provide a power conversion device.

The first invention is a storage case;
A plurality of capacitor elements housed in the housing case so as to have a pair of electrode surfaces at both ends, the electrode surfaces facing the same direction;
A pair of electrodes disposed on the electrode surface of the capacitor element and connected in parallel to the plurality of capacitor elements;
Among the plurality of capacitor elements, the capacitor element closest to the heating element other than the capacitor element is a high resistance capacitor element having a higher electrical resistance between the electrode surfaces than the other capacitor elements. (Claim 1).

The second invention is a power conversion device having a semiconductor module incorporating a semiconductor chip constituting a power conversion circuit, a reactor, and a capacitor,
The capacitor is
A storage case,
A plurality of capacitor elements housed in the housing case so as to have a pair of electrode surfaces at both ends, the electrode surfaces facing the same direction;
A pair of electrodes disposed on the electrode surface of the capacitor element and connected in parallel to the plurality of capacitor elements;
Among the plurality of capacitor elements, the capacitor element closest to the heating element in the power conversion circuit is a high-resistance capacitor element having a higher electrical resistance between the electrode surfaces than the other capacitor elements. In the power conversion device to be (claim 8).

Next, the function and effect of the first invention will be described.
In the present invention, among the plurality of capacitor elements, the capacitor element closest to the heating element is a high resistance capacitor element having a higher electric resistance between the electrode surfaces than other capacitor elements.
If it does in this way, the temperature rise of the capacitor | condenser element near a heat generating body can be suppressed, and the lifetime reduction of this capacitor | condenser element can be prevented. That is, as described above, the capacitor includes a plurality of capacitor elements, and each capacitor element generates heat due to a current flowing during use. In the present invention, among the plurality of capacitor elements, the capacitor element closest to the heating element is a high resistance capacitor element, so that the current flowing through the high resistance capacitor element can be reduced and the generated resistance heat can be reduced. Can do.

Therefore, even if the high-resistance capacitor element receives heat from the heating element, the resistance heat generated by the high-resistance capacitor element is small, so that a problem that the temperature is particularly high is less likely to occur compared to other capacitor elements. Thereby, the temperature of several capacitor | condenser elements can be equalize | homogenized, and only the capacitor | condenser element close | similar to a heat generating body can prevent the malfunction which temperature becomes high and a lifetime falls.
Therefore, in the present invention, the lifetime of the entire capacitor element can be extended. Further, it is not necessary to mount an extra capacitor element so that the capacitor element close to the heating element can operate normally even after failure.

Next, the function and effect of the second invention will be described. According to the present invention, in a power conversion device including a semiconductor module, a capacitor, and a reactor, a capacitor element closest to the heating element in the power conversion circuit among the plurality of capacitor elements included in the capacitor is a high resistance capacitor element. .
If it does in this way, the temperature rise of the capacitor element nearest to a heat generating body can be suppressed, and the power converter device which can prevent the lifetime reduction of this capacitor element can be provided.
That is, in the power conversion device, a heating element such as a reactor or a discharge resistor and a capacitor are housed in one case and are close to each other, so that the capacitor element is likely to receive heat from the heating element. In addition, when the power conversion device is mounted on a vehicle, the capacitor element is likely to receive heat from an adjacent engine.
However, in the present invention, among the plurality of capacitor elements, the capacitor element closest to the heating element is a high-resistance capacitor element, so that the current flowing through the high-resistance capacitor element can be reduced and the generated resistance heat can be reduced. . Thereby, the temperature rise of the capacitor element close to the heating element can be suppressed, and the lifetime of the capacitor element can be prevented from being reduced.

  As described above, according to the present invention, it is possible to provide a capacitor capable of suppressing a temperature rise of a capacitor element existing near a heating element and preventing a decrease in the lifetime of the capacitor element, and a power conversion device including the capacitor. Can do.

FIG. 4 is a cross-sectional view of the capacitor according to the first embodiment, which is a cross-sectional view taken along the line BB in FIG. 3. FIG. 4 is a cross-sectional view of the capacitor according to the first embodiment, which is a cross-sectional view taken along the line CC in FIG. 3. AA sectional drawing of FIG. FIG. 3 is an exploded perspective view of the capacitor in the first embodiment. 2 is an exploded perspective view of a wound film capacitor element in Example 1. FIG. In Example 1, (A) Capacitor element with low electric resistance (B) Sectional drawing of a capacitor element with high electric resistance. 2 is an exploded perspective view of the multilayer film capacitor element in Example 1. FIG. The circuit diagram of the power converter device in Example 2. FIG. Sectional drawing of the capacitor | condenser in Example 2. FIG. It is sectional drawing of the capacitor | condenser in Example 3, Comprising: The electrical resistance of a high resistance capacitor | condenser element is changed in steps. In Example 4, (A) Capacitor element with low electric resistance (B) Perspective view of capacitor element with high electric resistance. In Example 5, (A) Capacitor element with low electric resistance (B) Sectional drawing of a capacitor element with high electric resistance. In Example 6, (A) Capacitor element with low electric resistance (B) Perspective view of capacitor element with high electric resistance. In Example 7, (A) Capacitor element with low electric resistance (B) Enlarged surface view of a metallized film of a capacitor element with high electric resistance. The disassembled perspective view of the capacitor | condenser in a prior art example. Sectional drawing of the capacitor | condenser in a prior art example.

A preferred embodiment of the present invention described above will be described.
In the first invention, it is preferable that the capacitor element is arranged so that the electric resistance increases stepwise as it approaches the heating element.
This makes it easy to equalize the temperatures of the plurality of capacitor elements. That is, the heat generation is suppressed by increasing the electrical resistance of a capacitor element that is closer to the heating element and is susceptible to heat. As a result, the temperatures of the plurality of capacitor elements can be equalized.

Further, the capacitor element is a film capacitor element formed by winding or laminating a metallized film in which a metal film is formed on the surface of a dielectric film, and the high resistance capacitor element has a thickness of the dielectric film. It is preferable that the electric resistance is increased by making it thicker than the other capacitor elements.
The film capacitor element is likely to change its characteristics or shorten its life due to temperature rise. Therefore, when the present invention is applied to a capacitor using a film capacitor element, a particularly remarkable effect can be obtained.
Moreover, since a thick dielectric film is less expensive than a thin dielectric film, the manufacturing cost of a high-resistance capacitor element can be reduced by using the above configuration.

The reason why the electrical resistance increases when the thickness of the dielectric film is increased is as follows. For example, when a capacitor element is configured by winding a metallized film, the number of turns is less when winding a thick dielectric film than when winding a thin dielectric film if the size of the capacitor element is the same. Become. Therefore, the length of the metal coating in the direction orthogonal to the direction of current flow is shortened, and the electrical resistance is increased.
Also, when a capacitor element is configured by laminating metallized films, if the size of the capacitor element is the same, the number of laminated layers is less when a thick dielectric film is laminated than when a thin dielectric film is laminated. Become. As a result, the number of metal coatings through which current flows decreases, and the electrical resistance increases.

Further, the capacitor element is a film capacitor element formed by winding or laminating a metallized film in which a metal film is formed on the surface of a dielectric film, and the high resistance capacitor element is the metallization between the electrode surfaces. It is preferable that the electrical resistance is increased by making the length of the film longer than that of the other capacitor elements.
If it does in this way, the electrical resistance of a capacitor | condenser element can be made high only by lengthening the length between the electrode surfaces of a metallization film. That is, in the film capacitor element, when the length of the metallized film between the electrode surfaces is increased, the length of the metal film in the direction in which the current flows is increased, and the electric resistance is increased.
With the above configuration, it is not necessary to change the material of the metallized film between the high resistance capacitor element and other capacitor elements. In other words, it is possible to easily manufacture a high-resistance capacitor element because the electric resistance can be changed simply by changing the length without changing the thickness or material of the dielectric film and the metal coating constituting the metallized film. become.

The capacitor element is a film capacitor element formed by winding or laminating a metallized film in which a metal film is formed on the surface of a dielectric film, and the high resistance capacitor element has other thicknesses than the metal film. It is preferable that the electric resistance is increased by making the capacitor element thinner than the capacitor element.
In this way, the size and the number of turns or the number of layers of the high-resistance capacitor element and other capacitor elements can be made substantially the same. That is, since the thickness of the dielectric film is about several μm and the thickness of the metal film is about several mm, even if the thickness of the metal film is changed, the thickness of the entire metallized film hardly changes. Therefore, for example, when a capacitor element is formed by winding a metallized film, a metallized film having a thin metal film and a metallized film having a thick metal film are wound by the same number of turns, and a high resistance capacitor element and other capacitor elements When formed, the size after winding becomes almost the same.
Similarly, when a capacitor element is configured by laminating metallized films, the same number of metallized films with a thin metal film and metallized films with a thick metal film are laminated to form a high-resistance capacitor element and other elements. When the capacitor element is formed, the size after lamination is almost the same.
Thus, if the size of the high-resistance capacitor element and the other capacitor element can be made the same, it becomes easy to assemble them when they are stored in the storage case.

The capacitor element is a film capacitor element formed by winding or laminating a metallized film having a metal film formed on the surface of a dielectric film, and the high resistance capacitor element and the other capacitor element are the same. The metallized film is used, and the high resistance capacitor element is configured such that the electrical resistance is increased by reducing the number of turns or the number of layers of the metallized film as compared with the other capacitor elements. (Claim 6).
If it does in this way, it will become possible to manufacture a high resistance capacitor element and another capacitor element using the same metallized film. That is, the electrical resistance of the capacitor element can be changed only by changing the number of turns or the number of layers without changing the material or length of the metallized film. This makes it possible to easily manufacture a high resistance capacitor element.

The capacitor element is a film capacitor element formed by winding or laminating a metallized film in which a metal film is formed on the surface of a dielectric film, and the metallized film has a value higher than a predetermined value. A fuse that blows when a current flows is formed by patterning the metal film, and the high-resistance capacitor element has a width of the fuse in a direction orthogonal to the direction in which the current flows, as compared to other capacitor elements. It is preferable that the electrical resistance is increased by narrowing.
In this way, a high-resistance capacitor element and other capacitor elements can be manufactured using a metallized film having the same film thickness and type as the dielectric film and the metal coating, and the high-resistance capacitor element and others can be manufactured. The sizes of the capacitor elements can be made the same. Therefore, it is easy to manufacture and control the characteristics of the high-resistance capacitor element and other capacitor elements, and it is easy to assemble them when they are stored in the storage case.

Example 1
The capacitor | condenser and power converter device concerning the Example of this invention are demonstrated using FIGS.
As shown in FIGS. 1 to 4, the capacitor 1 of this example includes a storage case 2. In addition, a plurality of capacitor elements 3 having a pair of electrode surfaces 35 at both ends are stored in the storage case 2 so that the electrode surfaces 35 face the same direction. A pair of connection portions 4 a and 4 b for connecting a plurality of capacitor elements 3 in parallel are arranged on the electrode surface 35.
Among the plurality of capacitor elements 3, the capacitor element 30 closest to the heating element 5 other than the capacitor element 3 is a high-resistance capacitor element 30 having a higher electrical resistance between the electrode surfaces 35 than the other capacitor elements 3.
The details will be described below.

As shown in FIG. 5, the capacitor element 3 of this example is a film capacitor element 3 formed by winding a metallized film 6 having a metal film 61 formed on the surface of a dielectric film 60. Further, as shown in FIGS. 6A and 6B, the high resistance capacitor element 30 has a higher electric resistance by making the dielectric film 60 thicker than the other capacitor elements 3. It is configured.
The reason why the electrical resistance increases when the dielectric film 60 is thick is as follows. That is, when the high resistance capacitor element 30 manufactured by winding the thick metallized film 6 and the capacitor element 3 manufactured by winding the thin metallized film 6 are compared, the size after winding is the same. The high resistance capacitor element 30 has fewer turns. As a result, the length of the metal coating 61 in the direction orthogonal to the direction in which the current flows is shortened. Therefore, the cross-sectional area of the metal coating 61 in the direction orthogonal to the direction in which the current flows is reduced, and the electrical resistance between the electrode surfaces 35 is increased.

  On the other hand, the capacitor element 30 has a pair of electrode surfaces 35 formed at both ends in the winding axis direction. As shown in FIGS. 1 to 4, the plurality of capacitor elements 3 are arranged in the storage case 2 with the winding axis direction being the vertical direction (direction perpendicular to the case bottom surface). The capacitor element 3 is embedded in the resin 12 in the storage case 2. The capacitor element 3 has a substantially elliptic cylinder shape.

  Moreover, the connection part 4 of this example is bus bars 4a and 4b which consist of copper plates. The bus bars 4 a and 4 b are embedded in the resin 12. The bus bars 4a and 4b have connection terminals 50a and 50b for connecting to other electronic components. As shown in FIG. 3, the connection terminals 50 a and 50 b stand from the side portions of the bus bars 4 a and 4 b to the opening side of the storage case 2 and protrude from the surface of the resin 12. When the capacitor 1 is used, the connection terminals 50a and 50b generate heat due to the current. In this example, the connection terminals 50 a and 50 b are the heating elements 5.

The capacitor element 3 of this example may be configured by laminating a metallized film 6 as shown in FIG. In this case, the electrical resistance of the high resistance capacitor element 30 can be increased by making the dielectric film 60 thicker than the other capacitor elements 3.
The reason why the electrical resistance increases when the dielectric film 60 is thick is as follows. That is, if the size of the capacitor element 3 is the same, the number of laminated layers is smaller when the thick dielectric film 60 is laminated than when the thin dielectric film 60 is laminated. As a result, the number of metal coatings 61 through which current flows decreases, and the electrical resistance increases.

The effect of this example will be described.
As shown in FIGS. 1 and 4, the capacitor 1 of the present example is such that the capacitor element 30 closest to the heating element 5 among the plurality of capacitor elements 3 is more electrically connected between the electrode surfaces 35 than the other capacitor elements 3. The high-resistance capacitor element 30 has a high resistance.
If it does in this way, the temperature rise of the capacitor | condenser element 30 near the heat generating body 5 can be suppressed, and the lifetime reduction of this capacitor | condenser element 30 can be prevented. That is, as described above, the capacitor 1 includes a plurality of capacitor elements 3, and each capacitor element 3 generates heat due to a current flowing during use. In the present invention, since the capacitor element 30 closest to the heating element 5 among the plurality of capacitor elements 3 is the high resistance capacitor element 30, the current flowing through the high resistance capacitor element 30 can be reduced, and the generated resistance Heat can be reduced.

Therefore, even if the high resistance capacitor element 30 receives heat from the heating element 5, the resistance heat generated by the high resistance capacitor element 30 is small, so that the problem that the temperature is particularly high is less likely to occur compared to the other capacitor elements 3. Thereby, the temperature of the several capacitor | condenser element 3 can be equalize | homogenized, and only the capacitor | condenser element 30 close | similar to the heat generating body 5 can prevent the malfunction which a temperature becomes high and a lifetime falls.
Therefore, in this example, the lifetime of the capacitor element 3 as a whole can be extended. Further, there is no need to mount an extra capacitor element 3 so that the capacitor element 30 close to the heating element 5 can operate normally even after failure.

5 to 7, the capacitor element 3 is a film capacitor element 3 formed by winding or laminating a metallized film 6 having a metal film 61 formed on the surface of a dielectric film 60, and has a high resistance. The capacitor element 30 is configured such that the electrical resistance is increased by making the dielectric film 60 thicker than the other capacitor elements 3.
The film capacitor element 3 is liable to change its characteristics or shorten its life due to temperature rise. Therefore, when the present invention is applied to the capacitor 1 using the film capacitor element 3, a particularly remarkable effect can be obtained.
Further, since the thick dielectric film 60 is less expensive than the thin dielectric film 60, the manufacturing cost of the high-resistance capacitor element 30 can be reduced by adopting the above configuration.

  As described above, according to this example, it is possible to provide the capacitor 1 that can suppress the temperature rise of the capacitor element 3 existing near the heating element 5 and can prevent the lifetime of the capacitor element 3 from being reduced.

(Example 2)
In this example, the power conversion device 10 is configured using the capacitor 1. As shown in FIG. 8, the power conversion device 10 of this example includes a semiconductor module 11 including a semiconductor chip constituting a power conversion circuit, a reactor 51, a discharge resistor 52, and a capacitor 1.

  The power conversion device 10 of this example is mounted on a vehicle such as a hybrid car or an electric vehicle. As shown in FIG. 8, the power converter 10 includes a booster 10a and an inverter 10b. The voltage of the DC power source 14 is boosted by the booster 10a, and the boosted DC power is converted into AC power by the inverter 10b. Then, the AC power is used to drive the three-phase AC motor 15 to drive the vehicle. The capacitor 1 is used as a smoothing capacitor 1a for smoothing the voltage boosted by the boosting unit 10a.

  On the other hand, if the three-phase AC motor 15 stops and the electric charge remains in the capacitor 1, this electric charge may cause an electric shock. A discharge resistor 52 is provided in parallel with the capacitor 1.

  Note that a boosting capacitor 16 is provided in the boosting unit 10a. The capacitor element constituting the boosting capacitor 16 and the capacitor element 3 constituting the smoothing capacitor 1a described above may be housed in one housing case 2.

FIG. 9 shows a cross-sectional view of the capacitor 1 used in the power conversion device 10 of this example. The perspective view is substantially the same as FIG. As shown in FIG. 9, the capacitor 1 includes a storage case 2, and a plurality of capacitor elements 3 having a pair of electrode surfaces 35 at both ends are stored in the storage case 2 so that the electrode surfaces 35 face the same direction. Yes. In addition, a pair of connection portions 4 a and 4 b for connecting a plurality of capacitor elements 3 in parallel are arranged on the electrode surface 35.
Among the plurality of capacitor elements 3, the capacitor element 3 closest to the heating element 5 in the power conversion circuit is a high-resistance capacitor element 30 having a higher electrical resistance between the electrode surfaces 35 than the other capacitor elements 3.

  In this example, since the heat generation at the connection terminals 50a and 50b is negligibly small compared to the discharge resistor 52, only the capacitor element 3 close to the discharge resistor 52 is made the high resistance capacitor element 30. That is, the heating element 5 in this example is only the discharge resistor 52, and the connection terminals 50 a and 50 b are not included in the heating element 5.

Next, the function and effect of this example will be described. As shown in FIGS. 8 and 9, the power conversion device 10 of this example includes a semiconductor module 11, a capacitor 1, a reactor 50, and a discharge resistor 52, and the capacitor 1 has a plurality of capacitor elements 3. The capacitor element 30 closest to the heating element 5 in the power conversion circuit is a high resistance capacitor element 30.
In this way, it is possible to provide the power conversion device 10 that can suppress the temperature rise of the capacitor element 3 closest to the heating element 5 and can prevent the lifetime of the capacitor element 3 from being reduced.
That is, in the power conversion device 10, since the heating element 5 such as the reactor 50 and the discharge resistor 52 and the capacitor 1 are housed in one case and are close to each other, the capacitor element 3 receives the heat of the heating element 5. Cheap. Further, when the power conversion device 10 is mounted on a vehicle, the capacitor element 3 is likely to receive heat from an adjacent engine.

  However, in this example, since the capacitor element 3 closest to the heating element 5 among the plurality of capacitor elements 3 is the high resistance capacitor element 30, the current flowing through the high resistance capacitor element 30 can be reduced, and the generated resistance heat can be reduced. Can be reduced. Thereby, the temperature rise of the capacitor | condenser element 3 near the heat generating body 5 can be suppressed, and the lifetime reduction of this capacitor | condenser element 3 can be prevented.

  As described above, according to this example, it is possible to provide a power conversion device that can suppress the temperature rise of the capacitor element 3 existing near the heating element 5 and can prevent the lifetime of the capacitor element 3 from being reduced.

(Example 3)
In this example, the resistance value of the capacitor element 3 is changed. As shown in FIG. 10, in this example, the capacitor element 3 is arranged such that the electrical resistance increases stepwise as the heating element 5 is approached.
That is, in this example, the electric resistance of the capacitor 3a that is most susceptible to the heat of the heating element 5 is the highest, and then the electric resistance of the capacitor 3b that is likely to receive the heat of the heating element 5 is the second highest, and the capacitor 3c Has the lowest electrical resistance.

In this example, since the heat generation at the connection terminals 50a and 50b is negligibly small as compared with the discharge resistor 52 and the reactor 51, they are close to the discharge resistor 52 and the reactor 51 that mainly have a thermal effect on the capacitor element. Only the capacitor element 3 is a high resistance capacitor element 30. That is, the heating element 5 in this example is only the discharge resistor 52 and the reactor 51, and the connection terminals 50 a and 50 b are not included in the heating element 5.
In addition, the configuration is the same as that of the first embodiment.

  The effect of this example will be described. With the above configuration, the temperatures of the plurality of capacitor elements 3 can be easily equalized. That is, as shown in FIG. 10, the heat generation is suppressed by increasing the electrical resistance of the capacitor element 3 that is close to the heating element 5 and easily receives heat. Thereby, the temperature of the several capacitor | condenser element 3 can be equalized.

Example 4
In this example, the configuration of the capacitor element 3 is changed. As shown in FIGS. 11A and 11B, the capacitor element 3 of this example is a film capacitor element 3 formed by winding a metallized film 6 having a metal film 61 formed on the surface of a dielectric film 60. In addition, the high resistance capacitor element 30 is configured such that the electrical resistance is increased by making the length L2 of the metallized film 6 between the electrode surfaces 35 longer than the length L1 of the other capacitor elements 3.
When the length L in the winding axis direction of the metallized film 6 is increased, the length of the metal coating 61 in the direction in which current flows is increased, and the electrical resistance is increased.

Further, the film capacitor elements 3 and 30 can be configured by laminating the metallized film 6 (see FIG. 7). In this case, the electrical resistance of the high resistance capacitor element 30 can be increased by making the length of the metallized film 6 between the electrode surfaces 35 of the high resistance capacitor element 30 longer than the lengths of the other capacitor elements 3. it can.
In addition, the same configuration as that of the first embodiment is provided.

The effect of this example will be described. With the above configuration, the electrical resistance of the capacitor element 3 can be increased only by increasing the length L between the electrode surfaces 35 of the metallized film 6, and there is no need to change the material of the metallized film 6. That is, since the electric resistance can be changed only by changing the length L without changing the thickness and material of the dielectric film 60 and the metal coating 61 constituting the metallized film 6, the high resistance capacitor element 30 can be easily formed. It becomes possible to manufacture.
In addition, the same functions and effects as those of the first embodiment are provided.

(Example 5)
In this example, the configuration of the capacitor element 3 is changed. 12A and 12B, the capacitor element 3 of this example is a film capacitor formed by winding or laminating a metallized film 6 having a metal film 61 formed on the surface of a dielectric film 60. The high-resistance capacitor element 30, which is the element 3, is configured such that the electric resistance is increased by making the thickness of the metal coating 61 thinner than that of the other capacitor elements 3.
When the metal coating 61 is thinned, the resistance of the metal coating 61 is increased, so that the electrical resistance between the electrode surfaces 35 of the high-resistance capacitor element 30 is increased.
In addition, the same configuration as that of the first embodiment is provided.

In this way, the size and the number of turns or the number of layers of the high-resistance capacitor element 30 and the other capacitor element 3 can be made substantially the same. That is, since the thickness of the dielectric film 60 is about several μm and the thickness of the metal film 61 is about several mm, even if the thickness of the metal film 61 is changed, the thickness of the entire metallized film 6 is almost the same. It does not change. Therefore, for example, when the capacitor element 3 is formed by winding the metallized film 6, the metallized film 6 having a thin metal film 61 and the metallized film having a thick metal film 61 are wound by the same number of turns to form a high resistance capacitor element. When 30 and other capacitor elements 3 are formed, the sizes after winding are almost the same.
Similarly, when the capacitor element 3 is configured by laminating the metallized film 6, the same number of the metallized film 6 having the thin metal film 61 and the metallized film 6 having the thick metal film 61 are laminated, When the resistive capacitor element 30 and the other capacitor element 3 are formed, the sizes after lamination are almost the same.
Thus, if the size of the high-resistance capacitor element 30 and the other capacitor element 3 can be made the same, it becomes easy to assemble them when they are stored in the storage case 2.
In addition, the same functions and effects as those of the first embodiment are provided.

(Example 6)
In this example, the configuration of the capacitor element 3 is changed. As shown in FIGS. 13A and 13B, the capacitor element 3 of this example is a film capacitor element 3 formed by winding a metallized film 6 having a metal film 61 formed on the surface of a dielectric film 60. Yes, the high-resistance capacitor element 30 and the other capacitor element 3 use the same metallized film 6, and the high-resistance capacitor element 30 has fewer turns of the metallized film 6 than the other capacitor elements 3. Thus, the electric resistance is increased.
Similarly, the film capacitor element 3 can be configured by laminating the metallized film 6 (see FIG. 7). In this case, the same metallized film 6 is used for the high-resistance capacitor element 30 and the other capacitor element 3, and the number of laminated metallized films 6 is smaller than that of the other capacitor elements 3, whereby the high-resistance capacitor element 30. The electrical resistance can be increased.

Since the high resistance capacitor element 30 of this example has a small number of turns of the metallized film 6, the area of the electrode surface 35 is smaller than that of the other capacitor elements 3. When the number of turns of the metallized film 6 is small, the length of the metallized film 6 in the direction perpendicular to the direction in which the current flows is shortened, and as a result, the electrical resistance between the electrode surfaces 35 is increased.
Further, when the capacitor element 3 is configured by laminating the metallized film 6, if the number of laminations is reduced, the number of laminations of the metal coating 61 is reduced, so that the electrical resistance between the electrode surfaces 35 is increased.
In addition, the same configuration as that of the first embodiment is provided.

The effect of this example will be described. With the above configuration, the high resistance capacitor element 30 and the other capacitor element 3 can be manufactured using the same metallized film 6. That is, the electrical resistance of the capacitor element 3 can be changed only by changing the number of turns or the number of layers without changing the material or length of the metallized film 6. Thereby, the high resistance capacitor element 30 can be easily manufactured.
In addition, the same functions and effects as those of the first embodiment are provided.

(Example 7)
In this example, the configuration of the capacitor element 3 is changed. As shown in FIGS. 14A and 14B, the capacitor element 3 of this example is a film capacitor formed by winding or laminating a metallized film 6 in which a metal film 61 is formed on the surface of a dielectric film 60. On the metallized film 6, which is the element 3, a fuse 62 that is blown when a current higher than a predetermined value flows is formed by patterning the metal film 61.
That is, in the metallized film 6, a plurality of T-shaped slits 63 are formed in the dielectric film 60 in the metal coating 61. A gap between two adjacent T-shaped slits 63 is a fuse 62.
The high resistance capacitor element 30 is configured such that the electric resistance is increased by making the width W2 of the fuse 62 in the direction orthogonal to the direction in which the current flows smaller than the width W1 of the fuse 62 of the other capacitor element 3. Yes.
In addition, the same configuration as that of the first embodiment is provided.

  The effect of this example will be described. With the above configuration, the high-resistance capacitor element 30 and the other capacitor element 3 can be manufactured using the metallized film 6 having the same film thickness and the same types of the dielectric film 60 and the metal coating 61, and high The size of the resistor capacitor element 30 and the other capacitor element 3 can be made the same. Therefore, it is easy to manufacture and control the characteristics of the high-resistance capacitor element 30 and the other capacitor element 3, and it is easy to assemble them when they are stored in the storage case 2.

DESCRIPTION OF SYMBOLS 1 Capacitor 10 Power converter 2 Storage case 3 Capacitor element 30 High resistance capacitor element 4 Connection part 5 Heating element 6 Metallized film 60 Dielectric film 61 Metal film 62 Fuse

Claims (8)

A storage case,
A plurality of capacitor elements housed in the housing case so as to have a pair of electrode surfaces at both ends, the electrode surfaces facing the same direction;
A pair of electrodes disposed on the electrode surface of the capacitor element and connected in parallel to the plurality of capacitor elements;
Among the plurality of capacitor elements, the capacitor element closest to the heating element other than the capacitor element is a high resistance capacitor element having a higher electrical resistance between the electrode surfaces than the other capacitor elements. Capacitor.   2. The capacitor according to claim 1, wherein the capacitor element is arranged such that the electric resistance increases stepwise as the heating element is approached.   3. The capacitor element according to claim 1, wherein the capacitor element is a film capacitor element formed by winding or laminating a metallized film in which a metal film is formed on a surface of a dielectric film. A capacitor characterized in that the electrical resistance is increased by making the dielectric film thicker than the other capacitor elements.   3. The capacitor element according to claim 1, wherein the capacitor element is a film capacitor element formed by winding or laminating a metallized film in which a metal film is formed on a surface of a dielectric film. A capacitor characterized in that the electrical resistance is increased by making the length of the metallized film between the electrode surfaces longer than the other capacitor elements.   3. The capacitor element according to claim 1, wherein the capacitor element is a film capacitor element formed by winding or laminating a metallized film in which a metal film is formed on a surface of a dielectric film. A capacitor characterized in that the electric resistance is increased by making the thickness of the metal coating thinner than that of the other capacitor elements.   3. The capacitor element according to claim 1, wherein the capacitor element is a film capacitor element formed by winding or laminating a metallized film in which a metal film is formed on a surface of a dielectric film. The same metallized film as the capacitor element is used, and the high resistance capacitor element has a higher electric resistance by reducing the number of turns or the number of layers of the metallized film than the other capacitor elements. A capacitor characterized by being configured as follows.   The capacitor element according to claim 1 or 2, wherein the capacitor element is a film capacitor element formed by winding or laminating a metallized film having a metal film formed on a surface of a dielectric film. A fuse that blows when a current higher than a predetermined value flows is formed by patterning the metal film, and the high-resistance capacitor element has a width of the fuse in a direction orthogonal to a direction in which the current flows. A capacitor characterized in that the electric resistance is increased by making it narrower than the other capacitor elements. A power conversion device having a semiconductor module including a semiconductor chip constituting a power conversion circuit, a reactor, and a capacitor,
The capacitor is
A storage case,
A plurality of capacitor elements housed in the housing case so as to have a pair of electrode surfaces at both ends, the electrode surfaces facing the same direction;
A pair of electrodes disposed on the electrode surface of the capacitor element and connected in parallel to the plurality of capacitor elements;
Among the plurality of capacitor elements, the capacitor element closest to the heating element in the power conversion circuit is a high-resistance capacitor element having a higher electrical resistance between the electrode surfaces than the other capacitor elements. Power converter.

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