Capacitor block comprising a frame of electrically insulating material

Abstract

The invention relates to a capacitor block (100) comprising: at least one capacitor element (105); a first electrical conductor (110) comprising at least one conductive plate (112) bearing against a first end (105a) of the capacitor element (105) so as to be electrically connected to the capacitor element (105); and a first frame (101) made of electrically insulating material aligned with the peripheral edge of the conductive plate (112) so as to electrically insulate the plate relative to the environment of the capacitor block (100).

Description

Technical Field

[0001] The invention relates to a capacitor block, in particular a capacitor block for an electrical device, which is installed in a motor vehicle, in particular an electric or hybrid motor vehicle. Such an electrical device may be an inverter, a voltage converter or a battery charger. Background Art

[0002] As is known, in a capacitor block, a capacitor element can be arranged in a housing and embedded in a filling material, which mainly performs the function of supporting the capacitor element and protecting it from moisture. This filling material is usually in the form of a resin. The capacitor element is, for example, composed of a film wrapped around the terminals of the capacitor. Usually, the capacitor element is completely embedded in the resin so that the outside of the capacitor block is formed by the outer wall of the housing and the face formed by the resin. Only the electrical terminals extend out of the resin from the face. However, in some applications, particularly in electric or hybrid vehicles, it is sought to reduce the volume of electronic components. Now, in this capacitor block structure, the housing and the resin occupy a considerable space. In addition, it is necessary to leave space between the capacitor element and the side wall of the housing to allow the resin to flow before solidification.

[0003] A capacitor block is known in which the housing extends a height shorter than the height of the capacitor element. The housing then forms a basin just large enough to receive the resin at a first end of the capacitor block, the first end comprising an electrical connection between an electrical terminal of the capacitor block and an electrode of the capacitor element.

[0004] In this structure, the volume of the capacitor block is limited due to the short height of the housing. However, in this capacitor block structure, the portion of the capacitor element outside the resin is not protected from the external environment of the capacitor block. In particular, when the conductive plate is attached to the second end of the capacitor element, which is opposite to the first end, the conductive plate is not a priori insulated from the immediate environment.

[0005] Therefore, it is necessary to electrically protect the components of the capacitor block that are not protected by the resin. Summary of the invention

[0006] To this end, the present invention relates to a capacitor block, comprising:

[0007] at least one capacitive element;

[0008] a first electrical conductor comprising at least one conductive plate adjacent to a first end of the capacitive element to be electrically connected to the capacitive element; and

[0009] A first frame made of electrically insulating material is aligned with the peripheral edge of the conductive plates to electrically insulate the plates from the environment of the capacitive block.

[0010] By abutting the edges of the conductive plates, the first frame prevents current from flowing between conductive elements proximate to the capacitive block, flowing through the air and / or flowing along leakage paths.

[0011] According to an embodiment, the first frame comprises a first portion configured to abut a face of the conductive plate and a second portion extending laterally from the first portion to form a skirt around the conductive plate. Thus, the skirt forms an electrically insulating barrier relative to elements located near the conductive plate. In particular, the skirt faces an edge of the conductive plate. In particular, the face abutting the first portion is opposite to the first end of the capacitive element.

[0012] According to a variant, the skirt stops at a height from the first end that is less than half, or even one third or one quarter of the height of the capacitive element. Thus, the skirt does not extend over the entire height of the capacitive element, limiting the volume of the capacitive block.

[0013] According to a variant, the skirt extends from the first portion of the first frame for a distance to prevent current from flowing through the air between the conductive plate and the environment of the capacitive block.

[0014] According to an embodiment, the first electrical conductor comprises at least one connection portion extending from a peripheral edge of the conductive plate in a transverse direction relative to the conductive plate, and the first frame comprises a protective portion extending facing a face of the connection portion in order to electrically protect it from the environment of the capacitive block. In particular, the protective portion extends parallel to the face of the connection portion.

[0015] According to a variant, the first electrical conductor comprises a first connection portion extending away from the capacitive element and the first frame comprises a first protective portion extending from the first portion of the first frame in a direction opposite to that of the skirt formed by the second portion of the frame.

[0016] According to a variant, the first electrical conductor comprises a second connection portion extending from a conductive plate facing the capacitive element, and said first frame comprises a second protective portion formed by at least a portion of the skirt.

[0017] According to an embodiment, the first frame supports at least one second electrical conductor, which is configured to pass over the first electrical connector in order to connect the first electrical conductor to an electrical component other than the capacitive element, in particular to a filter element for filtering the power supply. Thus, the second electrical conductor is integrated into the first frame. Thus, the first frame has the function of an electrically insulating conductive plate and, by means of the second electrical conductor, also has the function of electrically connecting the first conductor and the different elements of the capacitive block.

[0018] According to a particular variant, one end of one connection portion, in particular the second connection portion, is configured to pass over one end of the second electrical conductor of the first frame in order to make an electrical connection.

[0019] According to one embodiment, the capacitor block further comprises an electrically insulating film in the form of a frame, which extends continuously along the inner edge of the first frame and radially towards the interior of the first frame. The insulating film in particular makes it possible to enlarge the leakage path between the conductive plate and the elements in the vicinity of the capacitor block, in particular the elements positioned facing the conductive plate.

[0020] According to an embodiment, the conductive plate adjoins at least one electrode of the capacitive element, said electrode being located at said first end of the capacitive element, so as to be connected thereto. In particular, the connection between the conductive plate and the electrode of the capacitive element is protected by a varnish.

[0021] The invention also relates to an electrical device, in particular configured to be installed in a vehicle, comprising a capacitor block according to the invention, a power electronics module and a cooling circuit. The conductive plate of the capacitor block abuts one face of the cooling circuit; and the power electronics module abuts the opposite face of the cooling circuit.

[0022] In particular, a power electronic module is an assembly comprising a plurality of semiconductor chips forming a circuit, the chips being packaged in the same package. More specifically, a power electronic module may form an inverter and include components through which power flows to supply an electric machine, such as an electric motor configured to drive a vehicle. The components are then intended to convert direct current into alternating current and vice versa. Such a power electronic module is particularly configured to allow power to flow in a controlled manner between a high voltage power supply battery and an electric machine.

[0023] According to an embodiment, the electrical device comprises a capacitor block, which comprises a first connection part and a first protection part. The first connection part is directly connected to an electrical terminal of the power electronic module, passing through a channel formed at least in part by an edge of a cooling circuit. Likewise, the first protection part of the first frame extends in the channel between the first connection part and the cooling circuit. Thus, the first protection part of the first frame electrically insulates the first connection part of the first electrical conductor from the cooling circuit. The first connection part in particular prevents arc formation in the air between the first connection part and the cooling circuit.

[0024] According to an embodiment, the electrical device comprises a layer of electrically insulating but thermally conductive material between the cooling circuit and the conductive plate, said layer of material entering the central opening of the first frame. The material enhances the electrical insulation of the conductive plate by insulating the conductive plate from elements of the environment positioned facing the outer face of the conductive plate. In particular, the material electrically insulates the conductive plate from the cooling circuit. However, the material facilitates heat exchange between the conductive plate and the cooling circuit.

[0025] According to an embodiment, the electrical device forms an inverter, a voltage converter or a battery charger. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The invention will be better understood and other details, characteristics and advantages of the invention will become apparent on reading the following description, which is given by way of non-limiting example with reference to the accompanying drawings, in which:

[0027] Figure 1 An example of a capacitor block according to an embodiment of the present invention is shown;

[0028] Figure 2 Shows Figure 1 The capacitor element of the capacitor block;

[0029] Figure 3 Shown without a frame Figure 1 Capacitor block;

[0030] Figure 4 Shows Figure 1 The frame of the capacitor block;

[0031] Figure 5 A variation is shown in which there is an additional insulating film on the frame;

[0032] Figure 6 A plan view of the frame is shown;

[0033] Figure 7 An example of an electrical device according to an embodiment of the present invention is shown;

[0034] Figure 8 Depicted in Figure 7 Examples of arcs that are prevented in electrical equipment;

[0035] Fig. 9 Depicted in Figure 7 Examples of leakage paths to be prevented in electrical equipment. DETAILED DESCRIPTION

[0036] It should be noted that the accompanying drawings disclose in a detailed manner an example according to the invention in order to implement the invention, said drawings can of course be used to better define the invention where appropriate.

[0037] Figure 1 A capacitor block 100 according to an example of the present invention is depicted. The capacitor block 100 includes a capacitor element 105. Such a capacitor element 105 is Figure 2. The capacitor element 105 particularly includes an electrode formed at a first end 105a of the capacitor element 105. The electrode may extend over the entire first end 105a. The capacitor element 105 particularly includes a body 107 that protects the capacitor element 105. In particular, the body 107 may be electrically insulating. The second end 105b opposite to the first end 105a includes an electrode with an opposite polarity to the electrode of the first end 105a. The electrode may extend over the entire second end 105b. Alternatively, the capacitor element 105 may group its electrodes together at a single end 105a, 105b. The capacitor element 105 is, for example, a film capacitor. The capacitor block 100 may include only a single capacitor element 105.

[0038] The capacitor block 100 further comprises a first electrical conductor 110, which comprises a conductive plate 112, which is adjacent to the first end 105a of the capacitor element 105 so as to be electrically connected thereto. In particular, the conductive plate 112 is adjacent to the electrode of the first end 105a so as to be connected thereto. To this end, the plate 112 may comprise a protrusion 112L, which may be Figure 3 As can be seen more clearly in FIG. 1 , a protrusion 112L is defined in the plate 112 so as to be welded to the first end 105a. A varnish, in particular a silicone varnish, may be applied to the connection between the protrusion 112L and the first end 105a, and may also be applied to the entire area of ​​the first end 105a for moisture protection. However, when the first end 105a has no electrode, a conductive plate may be adjacent to the first end 105a so as to ground the body 107 of the capacitive element 105.

[0039] The capacitor block 100 further comprises a first frame 101 made of an electrically insulating material, such as plastic. The frame 101 is aligned with the peripheral edge of the conductive plate 112 so as to electrically insulate the plate 112 from the environment of the capacitor block 100. For example, Figure 7 As shown (and described below), when the capacitor block 100 is integrated into an electrical device 200 , the frame 101 makes it possible to electrically insulate the conductive plates 112 from a cooling circuit 220 in the vicinity of the capacitor block 100 .

[0040] Figure 4 The frame 101 of the capacitor block 100 is shown. Thus, the frame 101 comprises a central opening bounded by an inner edge. The frame 101 particularly comprises a first portion 101a, which is configured to abut against a face of the conductive plate 112. The first portion 101a particularly abuts against a face of the conductive plate 112 opposite to the capacitor element 105. In particular, the first portion 101a comprises the inner edge of the frame 101.

[0041] The frame 101 may also include a second portion 101b extending laterally from the first portion 101a so as to form a skirt 101b surrounding the conductive plate 112. The skirt 101b helps to electrically insulate the conductive plate 112 from its environment. In particular, the skirt 101b faces the edge of the conductive plate 112 and exceeds the edge of the conductive plate 112 toward the second end 105b of the capacitor element 105. However, the skirt 101b does not reach the second end 105b of the capacitor element 105. Therefore, the volume of the capacitor block 100 is limited, especially in the direction perpendicular to the skirt 101b. In the accompanying drawings, the height of the skirt 101b, that is, the distance between the edge of the skirt 101b connected to the first portion 101a and the farthest edge of the skirt 101b, is less than half the height of the capacitor element 105. The height of the capacitor element 105 is in particular the distance between the first end 105a and the second end 105b.

[0042] For example, Figure 3 As shown, the capacitor block 100 may include an electrical terminal formed by connecting portions 113, 114 of a first conductor 110. The connecting portions 113, 114 extend from a peripheral edge of the conductive plate 112 in a lateral direction relative to the conductive plate 112. In particular, the first conductor 110 includes a first connecting portion 113 extending from the conductive plate 112 away from the capacitor element 105. The first connecting portion 113 is configured, for example, to abut a terminal of a power electronic module, in particular in an electrical device 200 (described below). The first electrical conductor 110 may include a second connecting portion 114 extending from the conductive plate 112 facing the capacitor element 105. The second portion 114 is configured, for example, to abut an electrical conductor in order to connect the capacitor block to a power source.

[0043] In order to protect the connection parts 113, 114, the frame 101 may include protection parts 103, 104 extending along the connection parts 113, 114 so as to electrically protect them from environmental influences of the capacitor block 100. In particular, the frame 101 includes a first protection part 103, which extends from the first part 101a of the frame 101 in a direction opposite to the direction of the skirt formed by the second part 101b of the frame 101. The first protection part 103 extends facing the face of the first connection part 113 so as to at least partially cover it. In particular, the first protection part 113 and the first connection part 103 overlap in a direction perpendicular to the face of the first connection part 113. The frame 101 includes a second protection part 104 formed by the skirt 101b. The protection parts 103, 104 in particular make it possible to electrically insulate the connection parts 113, 114 from nearby elements 200, in particular to prevent arcs from forming through the air or currents from flowing along leakage paths.

[0044] refer to Figure 6, the frame 101 may include at least one second electrical conductor 120 configured to cross the first electrical conductor 110 so as to connect the first electrical conductor 110 to an electrical component other than the capacitive element 105 , such as a filter element for filtering power.

[0045] In particular, the capacitor block 100 comprises a positive first conductor 110p and a negative first conductor 110n. The first conductors 110p, 110n are particularly coplanar on the face of the capacitor block 100 where the first end 105a of the capacitive element 105 is found. The frame 101 comprises a positive second electrical conductor 120p and a negative second electrical conductor 120n connected to the positive first conductor 110p and the negative first conductor 110n, respectively. Therefore, the second electrical conductor 120 is integrated into the frame 101. The second electrical conductor 120 is supported, for example, by the material of the frame 101 using a clip, or supported by press fit, or supported by overmolding. Therefore, the first frame 101 is also used to connect the first conductor 110 to an electrical component other than the capacitor element 105, such as a filter element for filtering power. In particular, one end 115 of the second connecting portion 114 is configured to cross one end 121 of the second electrical conductor 120 of the frame 101 for electrical connection. In particular, the connection area between the ends 115 , 121 is surrounded by a wall 106 which is integral with the insulating material of the frame 101 , in particular in order to provide electrical protection.

[0046] exist Figure 5 In the variant shown, an additional electrically insulating film 108 in the form of a frame extends continuously all along the inner edge of the frame 101, radially towards the interior of the frame 101, i.e. into the central opening of the frame 101. The insulating film 108 makes it possible in particular to enlarge the leakage path that passes along the first portion 101a of the frame 101 and that extends from the conductive plate 112 to elements in the vicinity of the capacitive block 100, in particular the cooling circuit 220 positioned facing the conductive plate, as will be described below. For example, the insulating film 108 is made of polyester (PET) and / or has a thickness of 200 microns, or a thickness of 180 to 220 microns.

[0047] Figure 7 An example of an electrical device 200 including a capacitor block 100 is shown. The electrical device 200 further includes a power electronics module 210 and a cooling circuit 220. The conductive plate 112 of the capacitor block 100 abuts one face of the cooling circuit 220, and the power electronics module 210 abuts the opposite face of the cooling circuit 220. The cooling circuit particularly includes a passage 221 between the power electronics module 210 and the capacitor block 100, through which a coolant flows. In particular, the components 105, 200, 220 are accommodated in a housing 225, in which Figure 7 Only part of it can be seen.

[0048] In particular, the first connection portion 113 of the first conductor 110 is directly connected to the electrical terminal 211 of the power electronic module 210. To this end, the first connection portion 113 spans the channel formed by the edge of the cooling circuit 220 and the wall of the housing 225. The first protective portion 103 of the frame 101 also extends in this channel between the first connection portion 113 and the cooling circuit 220. Therefore, the first protective portion 103 electrically insulates the first connection portion 103 from the cooling circuit 220. The first connection portion in particular prevents arcs from being formed in the air between the first connection portion 113 and the cooling circuit 220.

[0049] The electrical device 200 comprises in particular an electrically insulating but thermally conductive material layer 230, which may be Figure 8 and 9 This layer 230 is located between the cooling circuit 220 and the conductive plate 112. In particular, the layer 230 is a gap The material layer 230 is in particular adjusted to the central opening of the frame 101 in order to improve the contact between the material 230 and the conductive plate 112 and thus improve the heat dissipation between the conductive plate 112 and the cooling circuit 220 .

[0050] The first portion 101a of the frame 101 also has the function of limiting the compression of the material layer 230. For example, the first portion 101a prevents the material layer 230 from compressing more than 30% of the initial thickness of the layer 230. In particular, the thickness of the first portion 101a of the frame 101 is configured to prevent the layer 230 from compressing in this way. The first portion 101a of the frame 101 is, for example, 0.8 mm thick.

[0051] like Figure 8 As schematically shown, the frame 101 , in particular the skirt 101 b , improves the electrical insulation of the conductive plate 112 from the cooling circuit 220 , preventing the arc A1 from being formed through the air between the conductive plate 112 and the cooling circuit 220 .

[0052] like Fig. 9 As shown schematically, the insulating film 108 improves electrical insulation by enlarging the leakage path F2 between the conductive plate 112 and the cooling loop 220. This leakage path F2 starts from the conductive plate 112, along the boundary between the material layer 230 and the first part 101a of the frame 101, then the boundary between the material layer 230 and the insulating film 108, and ends at the cooling loop 220. Adding the insulating film 108 is more advantageous than enlarging the overlap between the first part 101a of the frame 101, because the insulating film 108 allows better heat dissipation than the frame 101.

[0053] According to one embodiment, referring to Figure 1 and 3The housing 150 can accommodate the second end 105b of the capacitor element 100 so as to receive the filler material to seal the second end 150b. The filler material is particularly an electrically insulating material, such as a resin. In particular, the first end 105a is located outside the housing 150. Before the housing 150 is filled with the filler material (particularly a liquid phase resin), the capacitor element 105 is positioned in the housing 150. The spacer 151 extending from the bottom of the housing 150 is adjacent to the conductive plate 112 forming a stopper. The spacer 151 determines the distance between the first end 105a of the capacitor element 105 and the bottom of the housing 105.

Claims

1. A capacitor block (100), comprising: at least one capacitive element (105), a first electrical conductor (110) comprising at least one conductive plate (112) adjacent to a first end (105a) of the capacitive element (105) to be electrically connected to the capacitive element (105), and a first frame (101) made of electrically insulating material, aligned with the peripheral edge of said conductive plate (112) to electrically insulate said plate (112) from the environment of the capacitor block (100), The first frame (101) comprises a first portion (101a) configured to abut against a surface of a conductive plate (112) and a second portion extending laterally from the first portion (101a) to form a skirt (101b) surrounding the conductive plate (112), And wherein the first electrical conductor (110) includes at least one connection portion (113, 114) extending from a peripheral edge of the conductive plate (112) in a lateral direction relative to the conductive plate (112), and wherein the first frame (101) includes a protective portion (103, 104) extending toward a surface of the connection portion (113, 114) to electrically protect it from the environment of the capacitor block (100).

2. The capacitor block (100) according to claim 1, wherein: The skirt (101b) extends from the first portion (101a) of the first frame (101) by a distance to prevent current from flowing through the air between the conductive plate (112) and the environment of the capacitor block (100).

3. The capacitor block (100) according to claim 1 or 2, wherein: The first electrical conductor (110) includes a first connecting portion (113) extending away from the capacitive element (105), and the first frame (101) includes a first protective portion (103) extending from a first portion (101a) of the first frame (101) in a direction opposite to the direction of a skirt formed by a second portion of the first frame (101).

4. The capacitor block (100) according to claim 1 or 2, wherein: The first electrical conductor (110) includes a second connection portion (114) extending from a conductive plate (112) facing the capacitive element (105), and the first frame (101) includes a second protective portion (104) formed by at least a portion of the skirt (101b).

5. The capacitor block (100) according to claim 1 or 2, wherein: The first frame (101) supports at least one second electrical conductor (120) configured to pass over the first electrical connector (110) to connect the first electrical conductor (110) to an electrical component other than the capacitive element (105).

6. The capacitor block (100) as claimed in claim 1 or 2, further comprising an electrically insulating film (108) in the form of a frame, which extends continuously along the inner edge of the first frame (101) and extends radially toward the inside of the first frame (101).

7. The capacitor block (100) according to claim 1 or 2, wherein: The conductive plate (112) abuts at least one electrode of the capacitive element (105), the electrode being located at the first end (105a) of the capacitive element (105) so as to be electrically connected thereto.

8. The capacitor block (100) according to claim 5, wherein: The first frame (101) supports at least one second electrical conductor (120) configured to pass over the first electrical connector (110) to connect the first electrical conductor (110) to a filter element for filtering power.

9. An electrical device (200), comprising a capacitor block (100), a power electronic module (210) and a cooling circuit (220) as described in any one of claims 1 to 8; the conductive plate (112) of the capacitor block (100) is adjacent to one surface of the cooling circuit (220), and the power electronic module (210) is adjacent to the opposite surface of the cooling circuit (220).

10. The electrical device (200) according to claim 9, wherein: The first frame (101) supports at least one second electrical conductor (120), the second electrical conductor being configured to pass over the first electrical connector (110) to connect the first electrical conductor (110) to an electrical component other than the capacitive element (105), and wherein the first connecting portion (113) is directly connected to an electrical terminal (211) of a power electronic module (220) through a channel at least partially formed by an edge of a cooling circuit (220), and wherein a first protective portion (103) of the first frame (101) extends in the channel between the first connecting portion (113) and the cooling circuit (220).

11. The electrical device (200) of claim 9 or 10, comprising an electrically insulating but thermally conductive material layer (230) between the cooling circuit (220) and the conductive plate (112), the material layer (230) entering the central opening of the first frame (101).

12. The electrical device (200) according to claim 9 or 10, wherein: The electric device (200) is configured to be installed in a vehicle.

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